Research ArticlePerformance Simulation Comparison for Parabolic Trough SolarCollectors in China

Jinping Wang123 Jun Wang13 Xiaolong Bi2 and Xiang Wang2

1 Jiangsu Provincial Key Laboratory of Solar Energy Science and Technology School of Energy and EnvironmentSoutheast University Nanjing 210096 China2School of Energy amp Power Engineering Nanjing Institute of Technology Nanjing 211167 China3College of Energy amp Environment Engineering Southeast University Nanjing 210096 China

Correspondence should be addressed to Jun Wang 101010980seueducn

Received 26 October 2015 Accepted 12 January 2016

Academic Editor Jegadesan Subbiah

Copyright copy 2016 Jinping Wang et al This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Parabolic trough systems are themost used concentrated solar power technologyThe operating performance and optical efficiencyof the parabolic trough solar collectors (PTCs) are different in different regions and different seasons To determine the optimumdesign and operation of the parabolic trough solar collector throughout the year an accurate estimation of the daily performanceis needed In this study a mathematical model for the optical efficiency of the parabolic trough solar collector was established andthree typical regions of solar thermal utilization in China were selectedThe performance characteristics of cosine effect shadowingeffect end loss effect and optical efficiency were calculated and simulated during a whole year in these three areas by using themathematical model The simulation results show that the optical efficiency of PTCs changes from 04 to 08 in a whole year Thehighest optical efficiency of PTCs is in June and the lowest is in December The optical efficiency of PTCs is mainly influenced bythe solar incidence angle The model is validated by comparing the test results in parabolic trough power plant with relative errorrange of 1 to about 5

1 Introduction

In recent years concentrated solar power (CSP) for electricityproduction promises to be one of the most viable optionsto replace fossil fuel power plants [1] Concentrated solarpower (CSP) systems use optical devices (usually mirrors)and sun-tracking systems to concentrate a large area ofsun light onto a smaller receiving area [2] There are fouravailable CSP technologies (a) parabolic troughs (b) solardishes (c) linear Fresnels and (d) solar power towers [3]China has announced plans to invest some CSPs projectsin Qinghai Tibet Gansu and other solar energy resourcerich regions during the Twelfth and Thirteenth Five-YearPlan (2014ndash2020) [4] Some of these projects are alreadyunder construction such as the 50MW parabolic troughsolar thermal power generation project in Delingha QinghaiProvince and the 10MW solar thermal power generationproject in Dunhuang Gansu Province [5] In the technol-ogy field of concentrated solar thermal power generationparabolic trough solar collector (PTC) plants are the most

developed ones of all commercially operating plants [6] Aparabolic trough consists of a linear parabolic mirror whichreflects and concentrates the received solar energy onto a tube(receiver) positioned along the focal line [7 8] PTCs can onlyuse direct solar radiation called beam radiation or DirectNormal Irradiance (DNI) that is the beam that come directlyfrom the solar disk but not those that could be reflected fromthe surroundings [9 10]

To determine the optimum design and operation of thesolar energy utilization technology throughout the year anaccurate estimation of the daily performance is essentialOver the years several researchers had generated calculationprocedures for obtaining synthetic data on a daily or hourlybasis Knight et al [11] had carried out the models for gen-erating hourly series of radiation and ambient temperaturevalues which aimed to replicate the statistics of long-termdata with just one year of generated data Petrakis et al[12] predicted and compared the performance and cost-effectiveness of passive and active solar systems in the islandby means of Typical Meteorological Year of Nicosia Cyprus

Hindawi Publishing CorporationInternational Journal of PhotoenergyVolume 2016 Article ID 9260943 16 pageshttpdxdoiorg10115520169260943

2 International Journal of Photoenergy

N (aperture normal)

S

(tracking angle)

(tracking axis)r

120588

120579i

Sun

Figure 1 A single axis tracking aperture

and then Florides et al [13] analyzed the weather data con-tained in a Typical Meteorological Year (TMY) and observedthe effect of these data on the simulated load of a typicalbuilding Garcıa-Barberena et al [14] evaluated the influenceof operational strategies on the performance of parabolictrough solar power plants with the aid of a computer programfor the simulation of the energy behavior of parabolic troughsolar power plants Bonilla et al [15] established a dynamicsimulator design and development of a direct steam genera-tion parabolic trough solar thermal power plant Wagner andWittmann [16] researched the influence of different operationstrategies on transient solar thermal power plant simulationmodels with molten salt as heat transfer fluid Huang et al[17] proposed a new analytical model of optical performanceand a modified integration algorithm is proposed to sim-ulate the performance of a parabolic trough solar collectorwith vacuum tube receiver Zhang et al [18] presented thebaseline for performance and economic evaluation of solarthermal systems based on the site test data and relatedreferences

The operating performance and optical efficiency of theparabolic trough solar collector are different in differentregions and different seasons The performance of PTCs isvery important for the operation and parabolic trough solarpower plants location choice However comparison analysison the operation performance of the parabolic trough solarcollectors in different regions was still relatively rare In thisstudy a mathematical model for the optical efficiency of theparabolic trough solar collector was established three typicalregions of solar thermal utilization in China were selectedThe operating characteristics of cosine effect shadowingeffect end loss effect and optical efficiency were calculatedand simulated by using the mathematical model during awhole year in these three areas

2 Methodology

21 Geometry Model for PTC Parabolic trough solar collec-tors are designed to operate with tracking about only one axisA tracking drive system rotates the collector about an axis ofrotation until the sun central ray and the aperture normal areaare coplanar Figure 1 shows the angle of incidence betweenthe collector normal and the beam radiation on a parabolictrough solar collector The angle of solar incidence resultsfrom the relationship between the sunrsquos position in the skyand the orientation of the collectors for a given location[19] The angle of solar incidence is not equal to 0∘ and the

Direct normal radiationDiffuse radiation

Figure 2 Direct and diffuse solar irradiation

reason is that the parabolic trough solar collector is generallyhorizontal layout single axis tracking the sun [20 21]

22 Mathematical Model of Total Optical Efficiency for PTCExtraterrestrial solar radiation follows a direct line fromthe sun to the earth Upon entering the earthrsquos atmospheresome solar radiation is diffused by air water moleculesand dust within the atmosphere The global solar irradianceover a horizontal surface that does not collect radiationdue to reflection or diffusion is composed of the directsolar irradiance and the diffuse irradiance [22] as shown inFigure 2

The relationship between the global solar irradiance thedirect solar irradiance and the diffuse irradiance can beexpressed as

119866ℎ= 119863ℎ+ 119861ℎ (1)

where 119861ℎis direct horizontal radiation and 119863

ℎis diffuse

radiationAs parabolic trough solar concentrators accept only DNI

diffuse irradiation is subtracted from the global irradiationto obtain the beam irradiation So formula (1) can be furtherdescribed as

119866ℎ= 119863ℎ+ 119861119899119860119888cos (120579

119894) (2)

where 119861119899is Direct Normal Irradiance (DNI) 120579

119894is the angle

of solar incidence and 119860119888is the collector aperture area

Power absorbed by the receiver of a parabolic trough solarconcentrator can be written as [23]

119876abs = 120578geo sdot 120578shadow sdot 120578endloss sdot 120578track sdot 120588119898 sdot 120578gen sdot 119870 sdot Cl

sdot 119860119888sdot 119861119899

(3)

where 120578geo is geometry effect 120578shadow is the factor for solarshading 120578endloss is the factor for the calculation of the relative

International Journal of Photoenergy 3

NSz

LPTC

120579i

Lf

Figure 3 End losses of a PTC

end loss 119870 is the Incident Angle Modifier Cl is the meancleanliness factor 120588

119898is the mirror reflectance 120578track is the

tracking error 120578gen is the general errorThe total optical efficiency for parabolic trough solar

collector is defined

120578opt =119876abs119860119888sdot 119861119899

= 120578geo sdot 120578shadow sdot 120578endloss sdot 120578track sdot 120588119898 sdot 120578gen sdot 119870 sdot Cl(4)

The values of 120578geo 120588119898 and 120578track can be measured by theinstrument [24]The incidence anglemodifier (IAM) correctsfor some additional reflection and absorption losses Theincidence angle modifier is given as an empirical fit toexperimental data for a given collector type The IncidentAngle Modifier 119870 is calculated according to [25 26]

119870 = cos (120579119894) + 000084120579

119894minus 000005369120579

119894

2

(5)

Figure 3 is a schematic diagram of the end loss of parabolictrough solar concentrator 119878 is the sun vector119873 is the vectorperpendicular to the aperture area and 120579

119894is the angle of solar

incidence When the sun light through the reflective mirrorgathered to the receiver a part of the length of the receivercannot accept the radiation energy by the reflective mirrorbecause the parabolic trough solar collector is generallyhorizontal layout and single axis tracking the sun The endlosses are the function of the focal length of the collector thelength of the collector and the incident angle The factor forthe end loss is [22 25]

120578endloss = 1 minus119871119891tan (120579

119894)

119871PTC (6)

where 119871119891is the focal length of PTCs 119871PTC is the length of

PTCsThe factor 120578shadow for the calculation of the shadow from

row to row at low solar altitude is [27] as shown in Figure 4Consider

120578shadow =1003816100381610038161003816cos 1205881003816100381610038161003816

119871 space

119908 (7)

where 119871 space is center distance of two parabolic troughconcentrators 119908 is aperture width 120588 is the sun-trackingangle Equation (7) is bounded with a minimum value of 0(rows are fully shaded) and a maximum value of 1 (rows arenot shaded)

w

Lspace

120588

120588

Figure 4 Two adjacent PTCs shadowing

23 Solar Incidence Angle Only the insolation that is directlynormal to the collector surface can be focused and thusbe available to warm the absorber tubes The angle ofincidence 120579

119894represents the angle between the beam radiation

on a surface and the plane normal to that surface Theangle of incidence will vary over the course of the day (aswell as throughout the year) and will heavily influence theperformance of the collectors [28]

Once the declination angle hour angle and zenith angleare known the angle of incidence on the collectors and thesun-tracking angle can be calculated The incidence anglefor a plane rotated about a horizontal north-south axiswith continuous east-west tracking to minimize the angle ofincidence and the sun-tracking angle is given by [29 30]

120579119894= arccosradiccos2 (120572) + cos2 (120575

119904) sin2 (120596)

120588 = tanminus1 [cos (120572

119904)

tan120572]

(8)

where 120596 is the hour angle 120575119904is the declination of the sun 120572

is the solar altitude angle 120572119904is the solar azimuth angle

24 Calculation for Position of the Sun The position ofthe sun depends on the hour angle the hour angle isnegative when the sun is east of the local meridian (in themorning) positive when the sun is west of the local meridian(afternoon) and zero when the sun is in line with the localmeridian (noon) The calculation formula of hour angle is[27]

120596 = (119905sol minus 12) sdot 15∘

(9)

where 119905sol is the solar time angleThere is an important distinction between standard time

and solar time In solar time the sun aligns with the localmeridian (120596 = 0) at exactly 1200 or ldquosolar noonrdquo Howeverstandard time is not based on the local meridian but on astandard meridian for the local time zoneThe standard timemust be adjusted to reflect the current time of day in solar

4 International Journal of Photoenergy

timeThe relationship between solar time and standard timein hours is

119905sol = 119905st minus 119905ad +119871 st minus 119871 loc15+EOT60 (10)

where 119905st is on a standardmeridian for the local time zone 119905adis daylight saving time adjustment 119871 st is standard meridianfor the local time zone 119871 loc is the local meridian of thecollector site EOT is an equation of time that determines thedeviation in local time from solar time as a function of theday of the year the calculation process of equation of time isas follows [29]

EOT = 000096 + 00171856 cos119861 minus 02951084 sin119861

minus 0134458 cos (2119861) minus 0376188 sin (2119861) (11)

where

119861 = 0986 (119889 minus 1) (12)

where 119889 is the day number of the year (1 for January 1 365 forDecember 31)

The declination angle is [30]

120575119904= 2345 sin (28011 + 0984119889) (13)

When the declination angle and hour angle were calcu-lated the solar altitude and solar azimuth which are used todescribe the sun position can be computedThe solar azimuth(120572119904) and the solar altitude (120572) angles are calculated [31]

120572 = arcsin [sin 120575119904sin120601 + cos120601 cos 120575

119904cos120596]

120572119904= sign (120596)

10038161003816100381610038161003816100381610038161003816

arccos [cos (90 minus 120572) sin120601 minus sin 120575

119904

sin (90 minus 120572) cos120601]

10038161003816100381610038161003816100381610038161003816

(14)

where 120601 is the latitude

25 Calculation Flowchart The flowchart of the method forthe end losses factor shadowing factor cosine effect andoptical efficiency of the PTC system is shown in the blockdiagram in Figure 5 From the flowchart it can be seen that thesolar altitude is calculated according time latitude angle andday number inputs then solar azimuth and angle of incidenceare calculated The cosine effect incidence angle modifierand sun-tracking angle are calculated by using the angle ofincidence The factor for the end loss is calculated by usingthe angle of incidence focus length and length of PTC Thetotal efficiency can be obtained by using the results of theabove calculation and the tracking error mirror reflectanceand general error inputs

26 Model Validation The model can be validated bycomparing Patnodersquos test results in SEGS VI concentratingsolar power station (2005) [28] based on some typical testconditions shown in Table 1 [7] The station is located at35∘0101584051010158401015840 north 117∘33101584032010158401015840 west [32] To calculate theoptical efficiency of the parabolic trough concentrator usingthe model the power absorbed by the receiver of the PTC

Input time Input latitudeangle

Input day number

Calculatesolar time

angleCalculate

declinationangle

Calculatesolar altitude

Calculatesolar azimuth

Calculateangle of

incidence

Input trackingerror mirror

reflectance andgeneral error

End

Input focus length and

length of PTC

Calculateincidence

angle modifierCalculate

sun-trackingangle

Calculatecosine effect

Calculatefactor for the

shadow

Calculatefactor for the

end loss

Calculate thecollector optical

efficiency

Figure 5 Flowchart of calculating the end losses factor shadowingfactor cosine effect and optical efficiency

Table 1 Main parameters of SEGS VIrsquos PTC [7]

Parameters DataFocus length 14mAperture width 5mLength of collector 471mAbsorber tube diameter 70mmAbsorptance 097Aperture area 2355m2

Mirror reflectance 094

is calculated according to formula (4) calculation resultsare compared with the test data The comparisons betweenthe simulations and experiments are shown in Figure 6 Ascan be seen from Figure 6 the numerical results on theheat rate error are between 4 and 20Wm2 with a relativeerror range of 1 to the estimated values of 5 Calculationresults are compared with that of experiments it is found thatcalculation results are lower than experiment data the mainreason is that the tracking error is assumed to be a constantin this paper and many other parameters like the thermicfluid and materials of the collector are not considered andthe error is affected Overall as can be seen from Figure 6themathematical model of this paper can correctly reflect theoperating characteristics of PTCs

3 Results and Discussion in TypicalAreas of China

A typical parabolic trough solar collector with the receiverof the radius of envelope 012 meters was calculated The

International Journal of Photoenergy 5

Table 2 Parameters of the parabolic trough solar collector

Parameters DataFocus length 18mAperture width 575mLength of collector 100mRadius of envelope of receiver 012mRow space 15mGeometry effects 098Cleanliness factor 095Mirror reflectance 0935Tracking error 0994

Hea

t rat

e (W

m2)

18 2012 14 168 106Time (h)

0

200

400

600

800

1000

1200

0

200

400

600

800

1000

1200

Dire

ct N

orm

al Ir

radi

ance

(Wm

2)

DNIPatnodersquos test result This paper

Figure 6 Comparisons between themode and Patnodersquos test resultsfor validation

parameters for the collector were shown at Table 2 prototypeas shown in Figure 7

The parabolic trough solar collector with these param-eters has been designed by Jiangsu Provincial Key Labora-tory of Solar Energy Science and Technology as shown inFigure 7

The three typical regions of China were chosen as thecomputing sites which are Lhasa Tibet Delingha Qinghaiand Dunhuang Gansu geographic coordinates as shown inTable 3

The optical efficiency cosine factor solar shading factorend loss factor and annual average values at any time inthese three areas were compared with simulation studies andanalysis For the convenience the first days per month in ayear were chosen for performance simulation Figure 8 showsthe changing trend of the collector optical efficiency Theoptical efficiency of PTC changes from 04 to 08 in a wholeyear The efficiency first decreased and then increased withthe turning point of the change at noonThehighest operatingcollector optical efficiency is in June and the efficiency isrelatively higher from April to August The lowest operatingcollector optical efficiency is in December and the efficiencyis relatively lower and the difference of efficiency in these

Table 3 Computing sites

Regions Geographic coordinatesDelingha N 3737∘ E 9737∘

Dunhuang N 4015∘ E 9468∘

Lhasa N 2967∘ E 9113∘

Figure 7 A prototype of parabolic trough solar collector

three areas is also greater in January October andNovemberFrom Figure 8 it is evident that the optical efficiency of PTCsoperated in Lhasa is higher than in Delingha and the opticalefficiency of PTCs operated in Delingha is higher than inDunhuang As can be seen from formula (4) the differenceof operating optical efficiency in these three regions is mainlydetermined by collector cosine effect end loss factor andsolar shading factor The angle of incidence of the sun is theangle between the rays of the sun and the normal The solarincidence angle changes with the angle of the solar zenithangle and the azimuth angle

From Figure 9 we can see that the changing trend of thecollector cosine effect is basically the same as the trend ofthe optical efficiency From October to March the value ofthe cosine effect is larger ranging from 07 to 098 whileit is smaller in October November December and JanuaryThe cosine effect in Lhasa is larger than in Delingha and inDelingha it is larger than Dunhuang

Figure 10 shows the changing trend of collector end lossfactor End losses occur at the ends of the PTCs where for anonzero incidence angle some length of the absorber tube isnot illuminated by solar radiation reflected from the mirrorsThe collector end loss factor is mainly affected by tangentangle of incidence of the sun As it can be seen from the figurethat the end loss factor is lowest at noon every day except forJune and July the minimum value appeared at sunrise andsunset in June and July and the value is relatively close inMarch February and November in all the three areas whichranged from 0985 to 1 The end loss factors in Delingha andDelingha are basically the same the value in Lhasa is slightlylarger than the other two areas

Figure 11 shows changing trend of shadowing effect Inthis study the two adjacent PTCs are arranged in parallelrows with about 15m of spacing within each row PTCstrack the sun toward the east at sunrise and toward thewest at sunset Due to the low solar altitude angle of the

6 International Journal of Photoenergy

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Jan

colle

ctor

aver

age o

ptic

al effi

cien

cy

(a)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Feb

colle

ctor

aver

age o

ptic

al effi

cien

cy

(b)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Mar

colle

ctor

aver

age o

ptic

al effi

cien

cy

(c)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10Ap

r col

lect

or av

erag

e opt

ical

effici

ency

(d)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

May

colle

ctor

aver

age o

ptic

al effi

cien

cy

(e)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Jun

colle

ctor

aver

age o

ptic

al effi

cien

cy

(f)

Figure 8 Continued

International Journal of Photoenergy 7

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10Ju

l col

lect

or av

erag

e opt

ical

effici

ency

(g)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Aug

colle

ctor

aver

age o

ptic

al effi

cien

cy

(h)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Sep

colle

ctor

aver

age o

ptic

al effi

cien

cy

(i)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Oct

colle

ctor

aver

age o

ptic

al effi

cien

cy

(j)

DunhuangLhasaDelingha

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Nov

colle

ctor

aver

age o

ptic

al effi

cien

cy

(k)

DunhuangLhasaDelingha

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Dec

colle

ctor

aver

age o

ptic

al effi

cien

cy

(l)

Figure 8 Collector optical efficiency

sun in the morning the eastern-most row of collectors willreceive full sun but this row will shade all subsequent rowsto the west As the sun rises and the collectors track thesun this mutual row shading effect decreases until a criticalzenith angle is reached at which no row shading occurs

Collector rows remain unshaded through the middle of theday from late morning through early afternoon As seen inthe figure losses are introduced by collector shading duringapproximately the first and last 90 minutes of operationeach day Because the collectors are single axis tracking in

8 International Journal of Photoenergy

00

02

04

06

08

10

Jan

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a)

00

02

04

06

08

10

Feb

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(b)

00

02

04

06

08

10

Mar

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c)

00

02

04

06

08

10Ap

r col

lect

or co

sine e

ffect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d)

00

02

04

06

08

10

May

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(e)

00

02

04

06

08

10

Jun

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(f)

Figure 9 Continued

International Journal of Photoenergy 9

00

02

04

06

08

10Ju

l row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(g)

00

02

04

06

08

10

Aug

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(h)

00

02

04

06

08

10

Sep

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(i)

00

02

04

06

08

10

Oct

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(j)

DunhuangLhasaDelingha

00

02

04

06

08

10

Nov

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(k)

DunhuangLhasaDelingha

00

02

04

06

08

10

Dec

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(l)

Figure 9 Collector cosine effect

a north-south orientation the length of time over which rowshading occurs does not vary significantly throughout theyear

The annual values of the twelve days of the data werecalculated Figure 12 shows the annual values of cosine effect

shadowing effect end loss effect and optical efficiency Asit can be seen from the figure that annual optical efficiencyof Lhasa is greater than Delingha and the latter is greaterthanDunhuang the annual optical efficiency per hour duringthe day of the sunrise to the sunset for Lhasa is 496

10 International Journal of Photoenergy

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Jan

end

loss

effec

t

(a)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Feb

end

loss

effec

t

(b)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Mar

end

loss

effec

t

(c)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000Ap

r end

loss

effec

t

(d)

4 6 8 10 12Time of day (h)

14 16 18 20 22 240965

0970

0975

0980

0985

0990

0995

1000

May

end

loss

effec

t

(e)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Jun

end

loss

effec

t

(f)

Figure 10 Continued

International Journal of Photoenergy 11

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000Ju

l end

loss

effec

t

(g)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Aug

end

loss

effec

t

(h)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Sep

end

loss

effec

t

(i)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Oct

end

loss

effec

t

(j)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Nov

end

loss

effec

t

DunhuangLhasaDelingha

(k)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Dec

end

loss

effec

t

DunhuangLhasaDelingha

(l)

Figure 10 End loss factor

Delingha is 461 andDunhuang is 448The annual valuesof shadowing effect and shadowing effect are very large closeto 100The trend of annual cosine effect change is consistentwith the trend of optical efficiency which reveals that theoptical efficiency is mainly influenced by the incident angle

of the sun nevertheless shadowing effect and end loss effectare weak in the effect of optical efficiency

From the analysis above we conclude that the opticalefficiency of parabolic trough solar concentrator collectorsmainly by the impact of the incident angle of the sun

12 International Journal of Photoenergy

00

02

04

06

08

10

Jan

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a)

00

02

04

06

08

10

Feb

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(b)

00

02

04

06

08

10

Mar

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c)

00

02

04

06

08

10Ap

r row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d)

00

02

04

06

08

10

May

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(e)

00

02

04

06

08

10

Jun

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(f)

Figure 11 Continued

International Journal of Photoenergy 13

00

02

04

06

08

10Ju

l row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(g)

00

02

04

06

08

10

Aug

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(h)

00

02

04

06

08

10

Sep

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(i)

00

02

04

06

08

10

Oct

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(j)

00

02

04

06

08

10

Nov

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

DunhuangLhasaDelingha

(k)

00

02

04

06

08

10

Dec

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

DunhuangLhasaDelingha

(l)

Figure 11 Shadowing effect

shadowing effect and end loss effect are almost negligibleThe incident angle of the sun ismainly influenced by differentgeographic locations of parabolic trough solar concentratingcollector So the conclusion has important implications for

the sites selection of parabolic trough solar thermal powerplant

For Parabolic Trough Power Plants location choice fromLhasa Dunhuang and Delingha in China the optical

14 International Journal of Photoenergy

DunhuangLhasaDelingha

00

02

04

06

08

10

Ann

ual c

olle

ctor

aver

age o

ptic

al effi

cien

cy

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a) Annual collector average optical efficiency

DunhuangLhasaDelingha

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Ann

ual e

nd lo

ss eff

ect

(b) Annual end loss effect

DunhuangLhasaDelingha

00

02

04

06

08

10

Ann

ual r

ow sh

adow

ing

effec

t

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c) Annual row shadowing

DunhuangLhasaDelingha

00

02

04

06

08

10A

nnua

l col

lect

or co

sine e

ffect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d) Annual collector cosine effect

Figure 12 Annual values of cosine effect shadowing effect end loss effect and optical efficiency

efficiency of PTCs in Lhasa is higher than the other 2regions

4 Conclusions

In the paper the optical efficiency calculation method ofparabolic trough solar collector was used to analyze andstudy the performance of parabolic trough solar collectorat Dunhuang Delingha and Lhasa in China The first dayof every month during a year was chosen as a time ofcalculation mainly cosine effect shadowing effect end losseffect and optical efficiency were calculated

From PTCs in these three areas in China simulationresults some overall conclusions could be derived as follows

(1) In this paper a mathematical model of parabolictrough solar concentrator is established which isvalidated by comparing the test results in SEGS VIand performance simulation results can correctlyreflect the operating characteristics of PTCs

(2) The optical efficiency of PTC changes from 04 to08 in a whole year The efficiency first decreased andthen increased with the turning point of the change atnoon The highest operating efficiency in these threeareas is in JuneThe lowest operating collector opticalefficiency is in December

(3) The shadowing losses are introduced by collectorshading during approximately the first and last 90

International Journal of Photoenergy 15

minutes of operation each day The end loss factorranged from 0985 to 1

(4) The optical efficiency of PTCs is mainly influencedby the incident angle of the sun shadowing effectand end loss effect are weak in the effect of opticalefficiency

(5) The annual optical efficiency of the parabolic troughsolar collector running in Lhasa is the highest in thesethree areas

The analytical method to performance simulation for theoptical efficiency of solar concentrator can be applied to otherconcentrated solar systems We are developing the programfor performance simulation for solar tower system in China

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

This study was simultaneously supported by the Key Labo-ratory Open Fund Project of Jiangsu Provincial Key Labo-ratory of Solar Energy Science and Technology (Grant noJPKLSST201504) and the Natural Science Foundation of theJiangsu Higher Education Institutions of China (Grant no14KJD470003)

References

[1] O Behar A Khellaf and K Mohammedi ldquoA review of studieson central receiver solar thermal power plantsrdquo Renewable andSustainable Energy Reviews vol 23 pp 12ndash39 2013

[2] A H Slocum D S Codd J Buongiorno et al ldquoConcentratedsolar power on demandrdquo Solar Energy vol 85 no 7 pp 1519ndash1529 2011

[3] H L Zhang J Baeyens J Degreve and G Caceres ldquoCon-centrated solar power plants review and design methodologyrdquoRenewable and Sustainable Energy Reviews vol 22 pp 466ndash4812013

[4] Office of the State Council of China ldquoStrategic action planfor energy development (2014ndash2020)rdquo 2014 (Chinese)httpwwwgovcnzhengcecontent2014-1119content 9222htm

[5] Dunhuang Energy Bureau Environmental Assessment Docu-ment for Dunhuang 10 MW of Solar Thermal Power Gen-eration Projects Dunhuang Energy Bureau 2015 (Chinese)httpwwwdunhuanggovcnReadNewsaspNewsID=16475

[6] A A Hachicha I Rodrıguez R Capdevila and A Oliva ldquoHeattransfer analysis and numerical simulation of a parabolic troughsolar collectorrdquoApplied Energy vol 111 no 11 pp 581ndash592 2013

[7] S A Kalogirou ldquoA detailed thermalmodel of a parabolic troughcollector receiverrdquo Energy vol 48 no 1 pp 298ndash306 2012

[8] H Muller-Steinhagen and F Trieb ldquolsquoConcentrating solarpowerrsquo A review of the technologyrdquo Quarterly of the RoyalAcademy of Engineering no 18 pp 43ndash50 2004

[9] A Fernandez-Garcıa E Zarza L Valenzuela and M PerezldquoParabolic-trough solar collectors and their applicationsrdquo

Renewable and Sustainable Energy Reviews vol 14 no 7 pp1695ndash1721 2010

[10] W Jinping W Jun Z Yaoming and B Xiaolong ldquoAnalysis ofheat transfer characteristics for parabolic trough solar collectorrdquoTransactions of the Chinese Society of Agricultural Engineeringvol 31 no 7 pp 185ndash192 2015 (Chinese)

[11] K M Knight S A Klein and J A Duffie ldquoA methodology forthe synthesis of hourly weather datardquo Solar Energy vol 46 no2 pp 109ndash120 1991

[12] M Petrakis H D Kambezidis S Lykoudis et al ldquoGeneration ofa lsquotypical meteorological yearrsquo for Nicosia Cyprusrdquo RenewableEnergy vol 13 no 3 pp 381ndash388 1998

[13] G Florides S Kalogirou K Theophilou et al ldquoAnalysis ofthe typical meteorological year (TMY) of Cyprus and houseload simulationrdquo in Proceedings of the 8th International IBPSAConference Eindhoven The Netherlands 2003

[14] J Garcıa-Barberena P GarciaM Sanchez et al ldquoAnalysis of theinfluence of operational strategies in plant performance usingSimulCET simulation software for parabolic trough powerplantsrdquo Solar Energy vol 86 no 1 pp 53ndash63 2012

[15] J Bonilla L J Yebra S Dormido and E Zarza ldquoParabolic-trough solar thermal power plant simulation scheme multi-objective genetic algorithm calibration and validationrdquo SolarEnergy vol 86 no 1 pp 531ndash540 2012

[16] P H Wagner and M Wittmann ldquoInfluence of different oper-ation strategies on transient solar thermal power plant simu-lation models with molten salt as heat transfer fluidrdquo EnergyProcedia vol 49 pp 1652ndash1663 2012

[17] W Huang P Hu and Z Chen ldquoPerformance simulation of aparabolic trough solar collectorrdquo Solar Energy vol 86 no 2 pp746ndash755 2012

[18] X Zhang W Xu T He et al ldquoSolar thermal system evaluationinChinardquo International Journal of Photoenergy vol 2015 ArticleID 163808 12 pages 2015

[19] W B Stine and R W Harrigan Solar Energy Fundamentalsand Design With Computer Applications John Wiley amp SonsHoboken NJ USA 1985

[20] W Jinping W Jun F Wei W Dengwen and Z YaomingldquoDevelopment and application of sun-tracking control systemfor parabolic trough solar collectorrdquo Transactions of the ChineseSociety of Agricultural Engineering vol 31 no 2 pp 45ndash52 2015

[21] R Dhanabal V Bharathi R Ranjitha A Ponni S Deepthi andP Mageshkannan ldquoComparison of efficiencies of solar trackersystems with static panel single-axis tracking system and dual-axis tracking system with fixed mountrdquo International Journal ofEngineering amp Technology vol 5 no 2 pp 1925ndash1933 2013

[22] CK Pandey andAKKatiyar ldquoAnote ondiffuse solar radiationon a tilted surfacerdquo Energy vol 34 no 11 pp 1764ndash1769 2009

[23] G Morin J Dersch W Platzer M Eck and A HaberleldquoComparison of linear Fresnel and parabolic trough collectorpower plantsrdquo Solar Energy vol 86 no 1 pp 1ndash12 2012

[24] K J Riffelmann ldquoComparison between PTR70 and UVACefficiency tests thermal loss measurements and Raytracingexperimentsrdquo Status Seminar vol 1 no 7 pp 187ndash197 2005

[25] F Lippke ldquoSimulation of the part load behaviour of a 30MW SEGS plantrdquo Tech Rep SAND95-1293 Sandia NationalLaboratories Albuquerque NM USA 1995

[26] V Dudley G Kolb M Sloan and D Kearney ldquoSEGS LS2solar collector test resultsrdquo Tech Rep SAND94-1884 SandiaNational Laboratories Albuquerque NM USA 1994

16 International Journal of Photoenergy

[27] M J Wagner and P Gilman ldquoTechnical manual for the SAMphysical trough modelrdquo Tech Rep Sandia National Laborato-ries Albuquerque NM USA 2011

[28] A M Patnode Simulation and performance evaluation ofparabolic trough solar power plants [Diss] University ofWisconsin-Madison Madison Wis USA 2006

[29] J Duffie and W Beckman Solar Engineering of Thermal Pro-cesses JohnWileyamp SonsHobokenNJUSA 3rd edition 2006

[30] M Ibanez Plana J Rosell Polo and J I Rosell Urrutia Tec-nologıa Solar Ediciones Mundi-Prensa Madrid Spain 2005

[31] B Bourges ldquoImprovement in solar declination computationrdquoSolar Energy vol 35 no 4 pp 367ndash369 1985

[32] httpwwwnrelgovcspsolarpacesproject detailcfmprojectID=33

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

2 International Journal of Photoenergy

N (aperture normal)

S

(tracking angle)

(tracking axis)r

120588

120579i

Sun

Figure 1 A single axis tracking aperture

and then Florides et al [13] analyzed the weather data con-tained in a Typical Meteorological Year (TMY) and observedthe effect of these data on the simulated load of a typicalbuilding Garcıa-Barberena et al [14] evaluated the influenceof operational strategies on the performance of parabolictrough solar power plants with the aid of a computer programfor the simulation of the energy behavior of parabolic troughsolar power plants Bonilla et al [15] established a dynamicsimulator design and development of a direct steam genera-tion parabolic trough solar thermal power plant Wagner andWittmann [16] researched the influence of different operationstrategies on transient solar thermal power plant simulationmodels with molten salt as heat transfer fluid Huang et al[17] proposed a new analytical model of optical performanceand a modified integration algorithm is proposed to sim-ulate the performance of a parabolic trough solar collectorwith vacuum tube receiver Zhang et al [18] presented thebaseline for performance and economic evaluation of solarthermal systems based on the site test data and relatedreferences

The operating performance and optical efficiency of theparabolic trough solar collector are different in differentregions and different seasons The performance of PTCs isvery important for the operation and parabolic trough solarpower plants location choice However comparison analysison the operation performance of the parabolic trough solarcollectors in different regions was still relatively rare In thisstudy a mathematical model for the optical efficiency of theparabolic trough solar collector was established three typicalregions of solar thermal utilization in China were selectedThe operating characteristics of cosine effect shadowingeffect end loss effect and optical efficiency were calculatedand simulated by using the mathematical model during awhole year in these three areas

2 Methodology

21 Geometry Model for PTC Parabolic trough solar collec-tors are designed to operate with tracking about only one axisA tracking drive system rotates the collector about an axis ofrotation until the sun central ray and the aperture normal areaare coplanar Figure 1 shows the angle of incidence betweenthe collector normal and the beam radiation on a parabolictrough solar collector The angle of solar incidence resultsfrom the relationship between the sunrsquos position in the skyand the orientation of the collectors for a given location[19] The angle of solar incidence is not equal to 0∘ and the

Direct normal radiationDiffuse radiation

Figure 2 Direct and diffuse solar irradiation

reason is that the parabolic trough solar collector is generallyhorizontal layout single axis tracking the sun [20 21]

22 Mathematical Model of Total Optical Efficiency for PTCExtraterrestrial solar radiation follows a direct line fromthe sun to the earth Upon entering the earthrsquos atmospheresome solar radiation is diffused by air water moleculesand dust within the atmosphere The global solar irradianceover a horizontal surface that does not collect radiationdue to reflection or diffusion is composed of the directsolar irradiance and the diffuse irradiance [22] as shown inFigure 2

The relationship between the global solar irradiance thedirect solar irradiance and the diffuse irradiance can beexpressed as

119866ℎ= 119863ℎ+ 119861ℎ (1)

where 119861ℎis direct horizontal radiation and 119863

ℎis diffuse

radiationAs parabolic trough solar concentrators accept only DNI

diffuse irradiation is subtracted from the global irradiationto obtain the beam irradiation So formula (1) can be furtherdescribed as

119866ℎ= 119863ℎ+ 119861119899119860119888cos (120579

119894) (2)

where 119861119899is Direct Normal Irradiance (DNI) 120579

119894is the angle

of solar incidence and 119860119888is the collector aperture area

Power absorbed by the receiver of a parabolic trough solarconcentrator can be written as [23]

119876abs = 120578geo sdot 120578shadow sdot 120578endloss sdot 120578track sdot 120588119898 sdot 120578gen sdot 119870 sdot Cl

sdot 119860119888sdot 119861119899

(3)

where 120578geo is geometry effect 120578shadow is the factor for solarshading 120578endloss is the factor for the calculation of the relative

International Journal of Photoenergy 3

NSz

LPTC

120579i

Lf

Figure 3 End losses of a PTC

end loss 119870 is the Incident Angle Modifier Cl is the meancleanliness factor 120588

119898is the mirror reflectance 120578track is the

tracking error 120578gen is the general errorThe total optical efficiency for parabolic trough solar

collector is defined

120578opt =119876abs119860119888sdot 119861119899

= 120578geo sdot 120578shadow sdot 120578endloss sdot 120578track sdot 120588119898 sdot 120578gen sdot 119870 sdot Cl(4)

The values of 120578geo 120588119898 and 120578track can be measured by theinstrument [24]The incidence anglemodifier (IAM) correctsfor some additional reflection and absorption losses Theincidence angle modifier is given as an empirical fit toexperimental data for a given collector type The IncidentAngle Modifier 119870 is calculated according to [25 26]

119870 = cos (120579119894) + 000084120579

119894minus 000005369120579

119894

2

(5)

Figure 3 is a schematic diagram of the end loss of parabolictrough solar concentrator 119878 is the sun vector119873 is the vectorperpendicular to the aperture area and 120579

119894is the angle of solar

incidence When the sun light through the reflective mirrorgathered to the receiver a part of the length of the receivercannot accept the radiation energy by the reflective mirrorbecause the parabolic trough solar collector is generallyhorizontal layout and single axis tracking the sun The endlosses are the function of the focal length of the collector thelength of the collector and the incident angle The factor forthe end loss is [22 25]

120578endloss = 1 minus119871119891tan (120579

119894)

119871PTC (6)

where 119871119891is the focal length of PTCs 119871PTC is the length of

PTCsThe factor 120578shadow for the calculation of the shadow from

row to row at low solar altitude is [27] as shown in Figure 4Consider

120578shadow =1003816100381610038161003816cos 1205881003816100381610038161003816

119871 space

119908 (7)

where 119871 space is center distance of two parabolic troughconcentrators 119908 is aperture width 120588 is the sun-trackingangle Equation (7) is bounded with a minimum value of 0(rows are fully shaded) and a maximum value of 1 (rows arenot shaded)

w

Lspace

120588

120588

Figure 4 Two adjacent PTCs shadowing

23 Solar Incidence Angle Only the insolation that is directlynormal to the collector surface can be focused and thusbe available to warm the absorber tubes The angle ofincidence 120579

119894represents the angle between the beam radiation

on a surface and the plane normal to that surface Theangle of incidence will vary over the course of the day (aswell as throughout the year) and will heavily influence theperformance of the collectors [28]

Once the declination angle hour angle and zenith angleare known the angle of incidence on the collectors and thesun-tracking angle can be calculated The incidence anglefor a plane rotated about a horizontal north-south axiswith continuous east-west tracking to minimize the angle ofincidence and the sun-tracking angle is given by [29 30]

120579119894= arccosradiccos2 (120572) + cos2 (120575

119904) sin2 (120596)

120588 = tanminus1 [cos (120572

119904)

tan120572]

(8)

where 120596 is the hour angle 120575119904is the declination of the sun 120572

is the solar altitude angle 120572119904is the solar azimuth angle

24 Calculation for Position of the Sun The position ofthe sun depends on the hour angle the hour angle isnegative when the sun is east of the local meridian (in themorning) positive when the sun is west of the local meridian(afternoon) and zero when the sun is in line with the localmeridian (noon) The calculation formula of hour angle is[27]

120596 = (119905sol minus 12) sdot 15∘

(9)

where 119905sol is the solar time angleThere is an important distinction between standard time

and solar time In solar time the sun aligns with the localmeridian (120596 = 0) at exactly 1200 or ldquosolar noonrdquo Howeverstandard time is not based on the local meridian but on astandard meridian for the local time zoneThe standard timemust be adjusted to reflect the current time of day in solar

4 International Journal of Photoenergy

timeThe relationship between solar time and standard timein hours is

119905sol = 119905st minus 119905ad +119871 st minus 119871 loc15+EOT60 (10)

where 119905st is on a standardmeridian for the local time zone 119905adis daylight saving time adjustment 119871 st is standard meridianfor the local time zone 119871 loc is the local meridian of thecollector site EOT is an equation of time that determines thedeviation in local time from solar time as a function of theday of the year the calculation process of equation of time isas follows [29]

EOT = 000096 + 00171856 cos119861 minus 02951084 sin119861

minus 0134458 cos (2119861) minus 0376188 sin (2119861) (11)

where

119861 = 0986 (119889 minus 1) (12)

where 119889 is the day number of the year (1 for January 1 365 forDecember 31)

The declination angle is [30]

120575119904= 2345 sin (28011 + 0984119889) (13)

When the declination angle and hour angle were calcu-lated the solar altitude and solar azimuth which are used todescribe the sun position can be computedThe solar azimuth(120572119904) and the solar altitude (120572) angles are calculated [31]

120572 = arcsin [sin 120575119904sin120601 + cos120601 cos 120575

119904cos120596]

120572119904= sign (120596)

10038161003816100381610038161003816100381610038161003816

arccos [cos (90 minus 120572) sin120601 minus sin 120575

119904

sin (90 minus 120572) cos120601]

10038161003816100381610038161003816100381610038161003816

(14)

where 120601 is the latitude

25 Calculation Flowchart The flowchart of the method forthe end losses factor shadowing factor cosine effect andoptical efficiency of the PTC system is shown in the blockdiagram in Figure 5 From the flowchart it can be seen that thesolar altitude is calculated according time latitude angle andday number inputs then solar azimuth and angle of incidenceare calculated The cosine effect incidence angle modifierand sun-tracking angle are calculated by using the angle ofincidence The factor for the end loss is calculated by usingthe angle of incidence focus length and length of PTC Thetotal efficiency can be obtained by using the results of theabove calculation and the tracking error mirror reflectanceand general error inputs

26 Model Validation The model can be validated bycomparing Patnodersquos test results in SEGS VI concentratingsolar power station (2005) [28] based on some typical testconditions shown in Table 1 [7] The station is located at35∘0101584051010158401015840 north 117∘33101584032010158401015840 west [32] To calculate theoptical efficiency of the parabolic trough concentrator usingthe model the power absorbed by the receiver of the PTC

Input time Input latitudeangle

Input day number

Calculatesolar time

angleCalculate

declinationangle

Calculatesolar altitude

Calculatesolar azimuth

Calculateangle of

incidence

Input trackingerror mirror

reflectance andgeneral error

End

Input focus length and

length of PTC

Calculateincidence

angle modifierCalculate

sun-trackingangle

Calculatecosine effect

Calculatefactor for the

shadow

Calculatefactor for the

end loss

Calculate thecollector optical

efficiency

Figure 5 Flowchart of calculating the end losses factor shadowingfactor cosine effect and optical efficiency

Table 1 Main parameters of SEGS VIrsquos PTC [7]

Parameters DataFocus length 14mAperture width 5mLength of collector 471mAbsorber tube diameter 70mmAbsorptance 097Aperture area 2355m2

Mirror reflectance 094

is calculated according to formula (4) calculation resultsare compared with the test data The comparisons betweenthe simulations and experiments are shown in Figure 6 Ascan be seen from Figure 6 the numerical results on theheat rate error are between 4 and 20Wm2 with a relativeerror range of 1 to the estimated values of 5 Calculationresults are compared with that of experiments it is found thatcalculation results are lower than experiment data the mainreason is that the tracking error is assumed to be a constantin this paper and many other parameters like the thermicfluid and materials of the collector are not considered andthe error is affected Overall as can be seen from Figure 6themathematical model of this paper can correctly reflect theoperating characteristics of PTCs

3 Results and Discussion in TypicalAreas of China

A typical parabolic trough solar collector with the receiverof the radius of envelope 012 meters was calculated The

International Journal of Photoenergy 5

Table 2 Parameters of the parabolic trough solar collector

Parameters DataFocus length 18mAperture width 575mLength of collector 100mRadius of envelope of receiver 012mRow space 15mGeometry effects 098Cleanliness factor 095Mirror reflectance 0935Tracking error 0994

Hea

t rat

e (W

m2)

18 2012 14 168 106Time (h)

0

200

400

600

800

1000

1200

0

200

400

600

800

1000

1200

Dire

ct N

orm

al Ir

radi

ance

(Wm

2)

DNIPatnodersquos test result This paper

Figure 6 Comparisons between themode and Patnodersquos test resultsfor validation

parameters for the collector were shown at Table 2 prototypeas shown in Figure 7

The parabolic trough solar collector with these param-eters has been designed by Jiangsu Provincial Key Labora-tory of Solar Energy Science and Technology as shown inFigure 7

The three typical regions of China were chosen as thecomputing sites which are Lhasa Tibet Delingha Qinghaiand Dunhuang Gansu geographic coordinates as shown inTable 3

The optical efficiency cosine factor solar shading factorend loss factor and annual average values at any time inthese three areas were compared with simulation studies andanalysis For the convenience the first days per month in ayear were chosen for performance simulation Figure 8 showsthe changing trend of the collector optical efficiency Theoptical efficiency of PTC changes from 04 to 08 in a wholeyear The efficiency first decreased and then increased withthe turning point of the change at noonThehighest operatingcollector optical efficiency is in June and the efficiency isrelatively higher from April to August The lowest operatingcollector optical efficiency is in December and the efficiencyis relatively lower and the difference of efficiency in these

Table 3 Computing sites

Regions Geographic coordinatesDelingha N 3737∘ E 9737∘

Dunhuang N 4015∘ E 9468∘

Lhasa N 2967∘ E 9113∘

Figure 7 A prototype of parabolic trough solar collector

three areas is also greater in January October andNovemberFrom Figure 8 it is evident that the optical efficiency of PTCsoperated in Lhasa is higher than in Delingha and the opticalefficiency of PTCs operated in Delingha is higher than inDunhuang As can be seen from formula (4) the differenceof operating optical efficiency in these three regions is mainlydetermined by collector cosine effect end loss factor andsolar shading factor The angle of incidence of the sun is theangle between the rays of the sun and the normal The solarincidence angle changes with the angle of the solar zenithangle and the azimuth angle

From Figure 9 we can see that the changing trend of thecollector cosine effect is basically the same as the trend ofthe optical efficiency From October to March the value ofthe cosine effect is larger ranging from 07 to 098 whileit is smaller in October November December and JanuaryThe cosine effect in Lhasa is larger than in Delingha and inDelingha it is larger than Dunhuang

Figure 10 shows the changing trend of collector end lossfactor End losses occur at the ends of the PTCs where for anonzero incidence angle some length of the absorber tube isnot illuminated by solar radiation reflected from the mirrorsThe collector end loss factor is mainly affected by tangentangle of incidence of the sun As it can be seen from the figurethat the end loss factor is lowest at noon every day except forJune and July the minimum value appeared at sunrise andsunset in June and July and the value is relatively close inMarch February and November in all the three areas whichranged from 0985 to 1 The end loss factors in Delingha andDelingha are basically the same the value in Lhasa is slightlylarger than the other two areas

Figure 11 shows changing trend of shadowing effect Inthis study the two adjacent PTCs are arranged in parallelrows with about 15m of spacing within each row PTCstrack the sun toward the east at sunrise and toward thewest at sunset Due to the low solar altitude angle of the

6 International Journal of Photoenergy

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Jan

colle

ctor

aver

age o

ptic

al effi

cien

cy

(a)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Feb

colle

ctor

aver

age o

ptic

al effi

cien

cy

(b)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Mar

colle

ctor

aver

age o

ptic

al effi

cien

cy

(c)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10Ap

r col

lect

or av

erag

e opt

ical

effici

ency

(d)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

May

colle

ctor

aver

age o

ptic

al effi

cien

cy

(e)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Jun

colle

ctor

aver

age o

ptic

al effi

cien

cy

(f)

Figure 8 Continued

International Journal of Photoenergy 7

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10Ju

l col

lect

or av

erag

e opt

ical

effici

ency

(g)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Aug

colle

ctor

aver

age o

ptic

al effi

cien

cy

(h)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Sep

colle

ctor

aver

age o

ptic

al effi

cien

cy

(i)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Oct

colle

ctor

aver

age o

ptic

al effi

cien

cy

(j)

DunhuangLhasaDelingha

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Nov

colle

ctor

aver

age o

ptic

al effi

cien

cy

(k)

DunhuangLhasaDelingha

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Dec

colle

ctor

aver

age o

ptic

al effi

cien

cy

(l)

Figure 8 Collector optical efficiency

sun in the morning the eastern-most row of collectors willreceive full sun but this row will shade all subsequent rowsto the west As the sun rises and the collectors track thesun this mutual row shading effect decreases until a criticalzenith angle is reached at which no row shading occurs

Collector rows remain unshaded through the middle of theday from late morning through early afternoon As seen inthe figure losses are introduced by collector shading duringapproximately the first and last 90 minutes of operationeach day Because the collectors are single axis tracking in

8 International Journal of Photoenergy

00

02

04

06

08

10

Jan

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a)

00

02

04

06

08

10

Feb

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(b)

00

02

04

06

08

10

Mar

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c)

00

02

04

06

08

10Ap

r col

lect

or co

sine e

ffect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d)

00

02

04

06

08

10

May

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(e)

00

02

04

06

08

10

Jun

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(f)

Figure 9 Continued

International Journal of Photoenergy 9

00

02

04

06

08

10Ju

l row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(g)

00

02

04

06

08

10

Aug

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(h)

00

02

04

06

08

10

Sep

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(i)

00

02

04

06

08

10

Oct

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(j)

DunhuangLhasaDelingha

00

02

04

06

08

10

Nov

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(k)

DunhuangLhasaDelingha

00

02

04

06

08

10

Dec

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(l)

Figure 9 Collector cosine effect

a north-south orientation the length of time over which rowshading occurs does not vary significantly throughout theyear

The annual values of the twelve days of the data werecalculated Figure 12 shows the annual values of cosine effect

shadowing effect end loss effect and optical efficiency Asit can be seen from the figure that annual optical efficiencyof Lhasa is greater than Delingha and the latter is greaterthanDunhuang the annual optical efficiency per hour duringthe day of the sunrise to the sunset for Lhasa is 496

10 International Journal of Photoenergy

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Jan

end

loss

effec

t

(a)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Feb

end

loss

effec

t

(b)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Mar

end

loss

effec

t

(c)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000Ap

r end

loss

effec

t

(d)

4 6 8 10 12Time of day (h)

14 16 18 20 22 240965

0970

0975

0980

0985

0990

0995

1000

May

end

loss

effec

t

(e)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Jun

end

loss

effec

t

(f)

Figure 10 Continued

International Journal of Photoenergy 11

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000Ju

l end

loss

effec

t

(g)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Aug

end

loss

effec

t

(h)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Sep

end

loss

effec

t

(i)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Oct

end

loss

effec

t

(j)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Nov

end

loss

effec

t

DunhuangLhasaDelingha

(k)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Dec

end

loss

effec

t

DunhuangLhasaDelingha

(l)

Figure 10 End loss factor

Delingha is 461 andDunhuang is 448The annual valuesof shadowing effect and shadowing effect are very large closeto 100The trend of annual cosine effect change is consistentwith the trend of optical efficiency which reveals that theoptical efficiency is mainly influenced by the incident angle

of the sun nevertheless shadowing effect and end loss effectare weak in the effect of optical efficiency

From the analysis above we conclude that the opticalefficiency of parabolic trough solar concentrator collectorsmainly by the impact of the incident angle of the sun

12 International Journal of Photoenergy

00

02

04

06

08

10

Jan

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a)

00

02

04

06

08

10

Feb

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(b)

00

02

04

06

08

10

Mar

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c)

00

02

04

06

08

10Ap

r row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d)

00

02

04

06

08

10

May

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(e)

00

02

04

06

08

10

Jun

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(f)

Figure 11 Continued

International Journal of Photoenergy 13

00

02

04

06

08

10Ju

l row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(g)

00

02

04

06

08

10

Aug

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(h)

00

02

04

06

08

10

Sep

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(i)

00

02

04

06

08

10

Oct

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(j)

00

02

04

06

08

10

Nov

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

DunhuangLhasaDelingha

(k)

00

02

04

06

08

10

Dec

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

DunhuangLhasaDelingha

(l)

Figure 11 Shadowing effect

shadowing effect and end loss effect are almost negligibleThe incident angle of the sun ismainly influenced by differentgeographic locations of parabolic trough solar concentratingcollector So the conclusion has important implications for

the sites selection of parabolic trough solar thermal powerplant

For Parabolic Trough Power Plants location choice fromLhasa Dunhuang and Delingha in China the optical

14 International Journal of Photoenergy

DunhuangLhasaDelingha

00

02

04

06

08

10

Ann

ual c

olle

ctor

aver

age o

ptic

al effi

cien

cy

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a) Annual collector average optical efficiency

DunhuangLhasaDelingha

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Ann

ual e

nd lo

ss eff

ect

(b) Annual end loss effect

DunhuangLhasaDelingha

00

02

04

06

08

10

Ann

ual r

ow sh

adow

ing

effec

t

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c) Annual row shadowing

DunhuangLhasaDelingha

00

02

04

06

08

10A

nnua

l col

lect

or co

sine e

ffect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d) Annual collector cosine effect

Figure 12 Annual values of cosine effect shadowing effect end loss effect and optical efficiency

efficiency of PTCs in Lhasa is higher than the other 2regions

4 Conclusions

In the paper the optical efficiency calculation method ofparabolic trough solar collector was used to analyze andstudy the performance of parabolic trough solar collectorat Dunhuang Delingha and Lhasa in China The first dayof every month during a year was chosen as a time ofcalculation mainly cosine effect shadowing effect end losseffect and optical efficiency were calculated

From PTCs in these three areas in China simulationresults some overall conclusions could be derived as follows

(1) In this paper a mathematical model of parabolictrough solar concentrator is established which isvalidated by comparing the test results in SEGS VIand performance simulation results can correctlyreflect the operating characteristics of PTCs

(2) The optical efficiency of PTC changes from 04 to08 in a whole year The efficiency first decreased andthen increased with the turning point of the change atnoon The highest operating efficiency in these threeareas is in JuneThe lowest operating collector opticalefficiency is in December

(3) The shadowing losses are introduced by collectorshading during approximately the first and last 90

International Journal of Photoenergy 15

minutes of operation each day The end loss factorranged from 0985 to 1

(4) The optical efficiency of PTCs is mainly influencedby the incident angle of the sun shadowing effectand end loss effect are weak in the effect of opticalefficiency

(5) The annual optical efficiency of the parabolic troughsolar collector running in Lhasa is the highest in thesethree areas

The analytical method to performance simulation for theoptical efficiency of solar concentrator can be applied to otherconcentrated solar systems We are developing the programfor performance simulation for solar tower system in China

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

This study was simultaneously supported by the Key Labo-ratory Open Fund Project of Jiangsu Provincial Key Labo-ratory of Solar Energy Science and Technology (Grant noJPKLSST201504) and the Natural Science Foundation of theJiangsu Higher Education Institutions of China (Grant no14KJD470003)

References

[1] O Behar A Khellaf and K Mohammedi ldquoA review of studieson central receiver solar thermal power plantsrdquo Renewable andSustainable Energy Reviews vol 23 pp 12ndash39 2013

[2] A H Slocum D S Codd J Buongiorno et al ldquoConcentratedsolar power on demandrdquo Solar Energy vol 85 no 7 pp 1519ndash1529 2011

[3] H L Zhang J Baeyens J Degreve and G Caceres ldquoCon-centrated solar power plants review and design methodologyrdquoRenewable and Sustainable Energy Reviews vol 22 pp 466ndash4812013

[4] Office of the State Council of China ldquoStrategic action planfor energy development (2014ndash2020)rdquo 2014 (Chinese)httpwwwgovcnzhengcecontent2014-1119content 9222htm

[5] Dunhuang Energy Bureau Environmental Assessment Docu-ment for Dunhuang 10 MW of Solar Thermal Power Gen-eration Projects Dunhuang Energy Bureau 2015 (Chinese)httpwwwdunhuanggovcnReadNewsaspNewsID=16475

[6] A A Hachicha I Rodrıguez R Capdevila and A Oliva ldquoHeattransfer analysis and numerical simulation of a parabolic troughsolar collectorrdquoApplied Energy vol 111 no 11 pp 581ndash592 2013

[7] S A Kalogirou ldquoA detailed thermalmodel of a parabolic troughcollector receiverrdquo Energy vol 48 no 1 pp 298ndash306 2012

[8] H Muller-Steinhagen and F Trieb ldquolsquoConcentrating solarpowerrsquo A review of the technologyrdquo Quarterly of the RoyalAcademy of Engineering no 18 pp 43ndash50 2004

[9] A Fernandez-Garcıa E Zarza L Valenzuela and M PerezldquoParabolic-trough solar collectors and their applicationsrdquo

Renewable and Sustainable Energy Reviews vol 14 no 7 pp1695ndash1721 2010

[10] W Jinping W Jun Z Yaoming and B Xiaolong ldquoAnalysis ofheat transfer characteristics for parabolic trough solar collectorrdquoTransactions of the Chinese Society of Agricultural Engineeringvol 31 no 7 pp 185ndash192 2015 (Chinese)

[11] K M Knight S A Klein and J A Duffie ldquoA methodology forthe synthesis of hourly weather datardquo Solar Energy vol 46 no2 pp 109ndash120 1991

[12] M Petrakis H D Kambezidis S Lykoudis et al ldquoGeneration ofa lsquotypical meteorological yearrsquo for Nicosia Cyprusrdquo RenewableEnergy vol 13 no 3 pp 381ndash388 1998

[13] G Florides S Kalogirou K Theophilou et al ldquoAnalysis ofthe typical meteorological year (TMY) of Cyprus and houseload simulationrdquo in Proceedings of the 8th International IBPSAConference Eindhoven The Netherlands 2003

[14] J Garcıa-Barberena P GarciaM Sanchez et al ldquoAnalysis of theinfluence of operational strategies in plant performance usingSimulCET simulation software for parabolic trough powerplantsrdquo Solar Energy vol 86 no 1 pp 53ndash63 2012

[15] J Bonilla L J Yebra S Dormido and E Zarza ldquoParabolic-trough solar thermal power plant simulation scheme multi-objective genetic algorithm calibration and validationrdquo SolarEnergy vol 86 no 1 pp 531ndash540 2012

[16] P H Wagner and M Wittmann ldquoInfluence of different oper-ation strategies on transient solar thermal power plant simu-lation models with molten salt as heat transfer fluidrdquo EnergyProcedia vol 49 pp 1652ndash1663 2012

[17] W Huang P Hu and Z Chen ldquoPerformance simulation of aparabolic trough solar collectorrdquo Solar Energy vol 86 no 2 pp746ndash755 2012

[18] X Zhang W Xu T He et al ldquoSolar thermal system evaluationinChinardquo International Journal of Photoenergy vol 2015 ArticleID 163808 12 pages 2015

[19] W B Stine and R W Harrigan Solar Energy Fundamentalsand Design With Computer Applications John Wiley amp SonsHoboken NJ USA 1985

[20] W Jinping W Jun F Wei W Dengwen and Z YaomingldquoDevelopment and application of sun-tracking control systemfor parabolic trough solar collectorrdquo Transactions of the ChineseSociety of Agricultural Engineering vol 31 no 2 pp 45ndash52 2015

[21] R Dhanabal V Bharathi R Ranjitha A Ponni S Deepthi andP Mageshkannan ldquoComparison of efficiencies of solar trackersystems with static panel single-axis tracking system and dual-axis tracking system with fixed mountrdquo International Journal ofEngineering amp Technology vol 5 no 2 pp 1925ndash1933 2013

[22] CK Pandey andAKKatiyar ldquoAnote ondiffuse solar radiationon a tilted surfacerdquo Energy vol 34 no 11 pp 1764ndash1769 2009

[23] G Morin J Dersch W Platzer M Eck and A HaberleldquoComparison of linear Fresnel and parabolic trough collectorpower plantsrdquo Solar Energy vol 86 no 1 pp 1ndash12 2012

[24] K J Riffelmann ldquoComparison between PTR70 and UVACefficiency tests thermal loss measurements and Raytracingexperimentsrdquo Status Seminar vol 1 no 7 pp 187ndash197 2005

[25] F Lippke ldquoSimulation of the part load behaviour of a 30MW SEGS plantrdquo Tech Rep SAND95-1293 Sandia NationalLaboratories Albuquerque NM USA 1995

[26] V Dudley G Kolb M Sloan and D Kearney ldquoSEGS LS2solar collector test resultsrdquo Tech Rep SAND94-1884 SandiaNational Laboratories Albuquerque NM USA 1994

16 International Journal of Photoenergy

[27] M J Wagner and P Gilman ldquoTechnical manual for the SAMphysical trough modelrdquo Tech Rep Sandia National Laborato-ries Albuquerque NM USA 2011

[28] A M Patnode Simulation and performance evaluation ofparabolic trough solar power plants [Diss] University ofWisconsin-Madison Madison Wis USA 2006

[29] J Duffie and W Beckman Solar Engineering of Thermal Pro-cesses JohnWileyamp SonsHobokenNJUSA 3rd edition 2006

[30] M Ibanez Plana J Rosell Polo and J I Rosell Urrutia Tec-nologıa Solar Ediciones Mundi-Prensa Madrid Spain 2005

[31] B Bourges ldquoImprovement in solar declination computationrdquoSolar Energy vol 35 no 4 pp 367ndash369 1985

[32] httpwwwnrelgovcspsolarpacesproject detailcfmprojectID=33

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

International Journal of Photoenergy 3

NSz

LPTC

120579i

Lf

Figure 3 End losses of a PTC

end loss 119870 is the Incident Angle Modifier Cl is the meancleanliness factor 120588

119898is the mirror reflectance 120578track is the

tracking error 120578gen is the general errorThe total optical efficiency for parabolic trough solar

collector is defined

120578opt =119876abs119860119888sdot 119861119899

= 120578geo sdot 120578shadow sdot 120578endloss sdot 120578track sdot 120588119898 sdot 120578gen sdot 119870 sdot Cl(4)

The values of 120578geo 120588119898 and 120578track can be measured by theinstrument [24]The incidence anglemodifier (IAM) correctsfor some additional reflection and absorption losses Theincidence angle modifier is given as an empirical fit toexperimental data for a given collector type The IncidentAngle Modifier 119870 is calculated according to [25 26]

119870 = cos (120579119894) + 000084120579

119894minus 000005369120579

119894

2

(5)

Figure 3 is a schematic diagram of the end loss of parabolictrough solar concentrator 119878 is the sun vector119873 is the vectorperpendicular to the aperture area and 120579

119894is the angle of solar

incidence When the sun light through the reflective mirrorgathered to the receiver a part of the length of the receivercannot accept the radiation energy by the reflective mirrorbecause the parabolic trough solar collector is generallyhorizontal layout and single axis tracking the sun The endlosses are the function of the focal length of the collector thelength of the collector and the incident angle The factor forthe end loss is [22 25]

120578endloss = 1 minus119871119891tan (120579

119894)

119871PTC (6)

where 119871119891is the focal length of PTCs 119871PTC is the length of

PTCsThe factor 120578shadow for the calculation of the shadow from

row to row at low solar altitude is [27] as shown in Figure 4Consider

120578shadow =1003816100381610038161003816cos 1205881003816100381610038161003816

119871 space

119908 (7)

where 119871 space is center distance of two parabolic troughconcentrators 119908 is aperture width 120588 is the sun-trackingangle Equation (7) is bounded with a minimum value of 0(rows are fully shaded) and a maximum value of 1 (rows arenot shaded)

w

Lspace

120588

120588

Figure 4 Two adjacent PTCs shadowing

23 Solar Incidence Angle Only the insolation that is directlynormal to the collector surface can be focused and thusbe available to warm the absorber tubes The angle ofincidence 120579

119894represents the angle between the beam radiation

on a surface and the plane normal to that surface Theangle of incidence will vary over the course of the day (aswell as throughout the year) and will heavily influence theperformance of the collectors [28]

Once the declination angle hour angle and zenith angleare known the angle of incidence on the collectors and thesun-tracking angle can be calculated The incidence anglefor a plane rotated about a horizontal north-south axiswith continuous east-west tracking to minimize the angle ofincidence and the sun-tracking angle is given by [29 30]

120579119894= arccosradiccos2 (120572) + cos2 (120575

119904) sin2 (120596)

120588 = tanminus1 [cos (120572

119904)

tan120572]

(8)

where 120596 is the hour angle 120575119904is the declination of the sun 120572

is the solar altitude angle 120572119904is the solar azimuth angle

24 Calculation for Position of the Sun The position ofthe sun depends on the hour angle the hour angle isnegative when the sun is east of the local meridian (in themorning) positive when the sun is west of the local meridian(afternoon) and zero when the sun is in line with the localmeridian (noon) The calculation formula of hour angle is[27]

120596 = (119905sol minus 12) sdot 15∘

(9)

where 119905sol is the solar time angleThere is an important distinction between standard time

and solar time In solar time the sun aligns with the localmeridian (120596 = 0) at exactly 1200 or ldquosolar noonrdquo Howeverstandard time is not based on the local meridian but on astandard meridian for the local time zoneThe standard timemust be adjusted to reflect the current time of day in solar

4 International Journal of Photoenergy

timeThe relationship between solar time and standard timein hours is

119905sol = 119905st minus 119905ad +119871 st minus 119871 loc15+EOT60 (10)

where 119905st is on a standardmeridian for the local time zone 119905adis daylight saving time adjustment 119871 st is standard meridianfor the local time zone 119871 loc is the local meridian of thecollector site EOT is an equation of time that determines thedeviation in local time from solar time as a function of theday of the year the calculation process of equation of time isas follows [29]

EOT = 000096 + 00171856 cos119861 minus 02951084 sin119861

minus 0134458 cos (2119861) minus 0376188 sin (2119861) (11)

where

119861 = 0986 (119889 minus 1) (12)

where 119889 is the day number of the year (1 for January 1 365 forDecember 31)

The declination angle is [30]

120575119904= 2345 sin (28011 + 0984119889) (13)

When the declination angle and hour angle were calcu-lated the solar altitude and solar azimuth which are used todescribe the sun position can be computedThe solar azimuth(120572119904) and the solar altitude (120572) angles are calculated [31]

120572 = arcsin [sin 120575119904sin120601 + cos120601 cos 120575

119904cos120596]

120572119904= sign (120596)

10038161003816100381610038161003816100381610038161003816

arccos [cos (90 minus 120572) sin120601 minus sin 120575

119904

sin (90 minus 120572) cos120601]

10038161003816100381610038161003816100381610038161003816

(14)

where 120601 is the latitude

25 Calculation Flowchart The flowchart of the method forthe end losses factor shadowing factor cosine effect andoptical efficiency of the PTC system is shown in the blockdiagram in Figure 5 From the flowchart it can be seen that thesolar altitude is calculated according time latitude angle andday number inputs then solar azimuth and angle of incidenceare calculated The cosine effect incidence angle modifierand sun-tracking angle are calculated by using the angle ofincidence The factor for the end loss is calculated by usingthe angle of incidence focus length and length of PTC Thetotal efficiency can be obtained by using the results of theabove calculation and the tracking error mirror reflectanceand general error inputs

26 Model Validation The model can be validated bycomparing Patnodersquos test results in SEGS VI concentratingsolar power station (2005) [28] based on some typical testconditions shown in Table 1 [7] The station is located at35∘0101584051010158401015840 north 117∘33101584032010158401015840 west [32] To calculate theoptical efficiency of the parabolic trough concentrator usingthe model the power absorbed by the receiver of the PTC

Input time Input latitudeangle

Input day number

Calculatesolar time

angleCalculate

declinationangle

Calculatesolar altitude

Calculatesolar azimuth

Calculateangle of

incidence

Input trackingerror mirror

reflectance andgeneral error

End

Input focus length and

length of PTC

Calculateincidence

angle modifierCalculate

sun-trackingangle

Calculatecosine effect

Calculatefactor for the

shadow

Calculatefactor for the

end loss

Calculate thecollector optical

efficiency

Figure 5 Flowchart of calculating the end losses factor shadowingfactor cosine effect and optical efficiency

Table 1 Main parameters of SEGS VIrsquos PTC [7]

Parameters DataFocus length 14mAperture width 5mLength of collector 471mAbsorber tube diameter 70mmAbsorptance 097Aperture area 2355m2

Mirror reflectance 094

is calculated according to formula (4) calculation resultsare compared with the test data The comparisons betweenthe simulations and experiments are shown in Figure 6 Ascan be seen from Figure 6 the numerical results on theheat rate error are between 4 and 20Wm2 with a relativeerror range of 1 to the estimated values of 5 Calculationresults are compared with that of experiments it is found thatcalculation results are lower than experiment data the mainreason is that the tracking error is assumed to be a constantin this paper and many other parameters like the thermicfluid and materials of the collector are not considered andthe error is affected Overall as can be seen from Figure 6themathematical model of this paper can correctly reflect theoperating characteristics of PTCs

3 Results and Discussion in TypicalAreas of China

A typical parabolic trough solar collector with the receiverof the radius of envelope 012 meters was calculated The

International Journal of Photoenergy 5

Table 2 Parameters of the parabolic trough solar collector

Parameters DataFocus length 18mAperture width 575mLength of collector 100mRadius of envelope of receiver 012mRow space 15mGeometry effects 098Cleanliness factor 095Mirror reflectance 0935Tracking error 0994

Hea

t rat

e (W

m2)

18 2012 14 168 106Time (h)

0

200

400

600

800

1000

1200

0

200

400

600

800

1000

1200

Dire

ct N

orm

al Ir

radi

ance

(Wm

2)

DNIPatnodersquos test result This paper

Figure 6 Comparisons between themode and Patnodersquos test resultsfor validation

parameters for the collector were shown at Table 2 prototypeas shown in Figure 7

The parabolic trough solar collector with these param-eters has been designed by Jiangsu Provincial Key Labora-tory of Solar Energy Science and Technology as shown inFigure 7

The three typical regions of China were chosen as thecomputing sites which are Lhasa Tibet Delingha Qinghaiand Dunhuang Gansu geographic coordinates as shown inTable 3

The optical efficiency cosine factor solar shading factorend loss factor and annual average values at any time inthese three areas were compared with simulation studies andanalysis For the convenience the first days per month in ayear were chosen for performance simulation Figure 8 showsthe changing trend of the collector optical efficiency Theoptical efficiency of PTC changes from 04 to 08 in a wholeyear The efficiency first decreased and then increased withthe turning point of the change at noonThehighest operatingcollector optical efficiency is in June and the efficiency isrelatively higher from April to August The lowest operatingcollector optical efficiency is in December and the efficiencyis relatively lower and the difference of efficiency in these

Table 3 Computing sites

Regions Geographic coordinatesDelingha N 3737∘ E 9737∘

Dunhuang N 4015∘ E 9468∘

Lhasa N 2967∘ E 9113∘

Figure 7 A prototype of parabolic trough solar collector

three areas is also greater in January October andNovemberFrom Figure 8 it is evident that the optical efficiency of PTCsoperated in Lhasa is higher than in Delingha and the opticalefficiency of PTCs operated in Delingha is higher than inDunhuang As can be seen from formula (4) the differenceof operating optical efficiency in these three regions is mainlydetermined by collector cosine effect end loss factor andsolar shading factor The angle of incidence of the sun is theangle between the rays of the sun and the normal The solarincidence angle changes with the angle of the solar zenithangle and the azimuth angle

From Figure 9 we can see that the changing trend of thecollector cosine effect is basically the same as the trend ofthe optical efficiency From October to March the value ofthe cosine effect is larger ranging from 07 to 098 whileit is smaller in October November December and JanuaryThe cosine effect in Lhasa is larger than in Delingha and inDelingha it is larger than Dunhuang

Figure 10 shows the changing trend of collector end lossfactor End losses occur at the ends of the PTCs where for anonzero incidence angle some length of the absorber tube isnot illuminated by solar radiation reflected from the mirrorsThe collector end loss factor is mainly affected by tangentangle of incidence of the sun As it can be seen from the figurethat the end loss factor is lowest at noon every day except forJune and July the minimum value appeared at sunrise andsunset in June and July and the value is relatively close inMarch February and November in all the three areas whichranged from 0985 to 1 The end loss factors in Delingha andDelingha are basically the same the value in Lhasa is slightlylarger than the other two areas

Figure 11 shows changing trend of shadowing effect Inthis study the two adjacent PTCs are arranged in parallelrows with about 15m of spacing within each row PTCstrack the sun toward the east at sunrise and toward thewest at sunset Due to the low solar altitude angle of the

6 International Journal of Photoenergy

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Jan

colle

ctor

aver

age o

ptic

al effi

cien

cy

(a)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Feb

colle

ctor

aver

age o

ptic

al effi

cien

cy

(b)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Mar

colle

ctor

aver

age o

ptic

al effi

cien

cy

(c)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10Ap

r col

lect

or av

erag

e opt

ical

effici

ency

(d)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

May

colle

ctor

aver

age o

ptic

al effi

cien

cy

(e)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Jun

colle

ctor

aver

age o

ptic

al effi

cien

cy

(f)

Figure 8 Continued

International Journal of Photoenergy 7

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10Ju

l col

lect

or av

erag

e opt

ical

effici

ency

(g)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Aug

colle

ctor

aver

age o

ptic

al effi

cien

cy

(h)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Sep

colle

ctor

aver

age o

ptic

al effi

cien

cy

(i)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Oct

colle

ctor

aver

age o

ptic

al effi

cien

cy

(j)

DunhuangLhasaDelingha

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Nov

colle

ctor

aver

age o

ptic

al effi

cien

cy

(k)

DunhuangLhasaDelingha

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Dec

colle

ctor

aver

age o

ptic

al effi

cien

cy

(l)

Figure 8 Collector optical efficiency

sun in the morning the eastern-most row of collectors willreceive full sun but this row will shade all subsequent rowsto the west As the sun rises and the collectors track thesun this mutual row shading effect decreases until a criticalzenith angle is reached at which no row shading occurs

Collector rows remain unshaded through the middle of theday from late morning through early afternoon As seen inthe figure losses are introduced by collector shading duringapproximately the first and last 90 minutes of operationeach day Because the collectors are single axis tracking in

8 International Journal of Photoenergy

00

02

04

06

08

10

Jan

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a)

00

02

04

06

08

10

Feb

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(b)

00

02

04

06

08

10

Mar

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c)

00

02

04

06

08

10Ap

r col

lect

or co

sine e

ffect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d)

00

02

04

06

08

10

May

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(e)

00

02

04

06

08

10

Jun

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(f)

Figure 9 Continued

International Journal of Photoenergy 9

00

02

04

06

08

10Ju

l row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(g)

00

02

04

06

08

10

Aug

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(h)

00

02

04

06

08

10

Sep

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(i)

00

02

04

06

08

10

Oct

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(j)

DunhuangLhasaDelingha

00

02

04

06

08

10

Nov

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(k)

DunhuangLhasaDelingha

00

02

04

06

08

10

Dec

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(l)

Figure 9 Collector cosine effect

a north-south orientation the length of time over which rowshading occurs does not vary significantly throughout theyear

The annual values of the twelve days of the data werecalculated Figure 12 shows the annual values of cosine effect

shadowing effect end loss effect and optical efficiency Asit can be seen from the figure that annual optical efficiencyof Lhasa is greater than Delingha and the latter is greaterthanDunhuang the annual optical efficiency per hour duringthe day of the sunrise to the sunset for Lhasa is 496

10 International Journal of Photoenergy

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Jan

end

loss

effec

t

(a)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Feb

end

loss

effec

t

(b)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Mar

end

loss

effec

t

(c)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000Ap

r end

loss

effec

t

(d)

4 6 8 10 12Time of day (h)

14 16 18 20 22 240965

0970

0975

0980

0985

0990

0995

1000

May

end

loss

effec

t

(e)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Jun

end

loss

effec

t

(f)

Figure 10 Continued

International Journal of Photoenergy 11

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000Ju

l end

loss

effec

t

(g)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Aug

end

loss

effec

t

(h)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Sep

end

loss

effec

t

(i)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Oct

end

loss

effec

t

(j)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Nov

end

loss

effec

t

DunhuangLhasaDelingha

(k)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Dec

end

loss

effec

t

DunhuangLhasaDelingha

(l)

Figure 10 End loss factor

Delingha is 461 andDunhuang is 448The annual valuesof shadowing effect and shadowing effect are very large closeto 100The trend of annual cosine effect change is consistentwith the trend of optical efficiency which reveals that theoptical efficiency is mainly influenced by the incident angle

of the sun nevertheless shadowing effect and end loss effectare weak in the effect of optical efficiency

From the analysis above we conclude that the opticalefficiency of parabolic trough solar concentrator collectorsmainly by the impact of the incident angle of the sun

12 International Journal of Photoenergy

00

02

04

06

08

10

Jan

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a)

00

02

04

06

08

10

Feb

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(b)

00

02

04

06

08

10

Mar

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c)

00

02

04

06

08

10Ap

r row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d)

00

02

04

06

08

10

May

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(e)

00

02

04

06

08

10

Jun

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(f)

Figure 11 Continued

International Journal of Photoenergy 13

00

02

04

06

08

10Ju

l row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(g)

00

02

04

06

08

10

Aug

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(h)

00

02

04

06

08

10

Sep

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(i)

00

02

04

06

08

10

Oct

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(j)

00

02

04

06

08

10

Nov

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

DunhuangLhasaDelingha

(k)

00

02

04

06

08

10

Dec

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

DunhuangLhasaDelingha

(l)

Figure 11 Shadowing effect

shadowing effect and end loss effect are almost negligibleThe incident angle of the sun ismainly influenced by differentgeographic locations of parabolic trough solar concentratingcollector So the conclusion has important implications for

the sites selection of parabolic trough solar thermal powerplant

For Parabolic Trough Power Plants location choice fromLhasa Dunhuang and Delingha in China the optical

14 International Journal of Photoenergy

DunhuangLhasaDelingha

00

02

04

06

08

10

Ann

ual c

olle

ctor

aver

age o

ptic

al effi

cien

cy

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a) Annual collector average optical efficiency

DunhuangLhasaDelingha

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Ann

ual e

nd lo

ss eff

ect

(b) Annual end loss effect

DunhuangLhasaDelingha

00

02

04

06

08

10

Ann

ual r

ow sh

adow

ing

effec

t

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c) Annual row shadowing

DunhuangLhasaDelingha

00

02

04

06

08

10A

nnua

l col

lect

or co

sine e

ffect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d) Annual collector cosine effect

Figure 12 Annual values of cosine effect shadowing effect end loss effect and optical efficiency

efficiency of PTCs in Lhasa is higher than the other 2regions

4 Conclusions

In the paper the optical efficiency calculation method ofparabolic trough solar collector was used to analyze andstudy the performance of parabolic trough solar collectorat Dunhuang Delingha and Lhasa in China The first dayof every month during a year was chosen as a time ofcalculation mainly cosine effect shadowing effect end losseffect and optical efficiency were calculated

From PTCs in these three areas in China simulationresults some overall conclusions could be derived as follows

(1) In this paper a mathematical model of parabolictrough solar concentrator is established which isvalidated by comparing the test results in SEGS VIand performance simulation results can correctlyreflect the operating characteristics of PTCs

(2) The optical efficiency of PTC changes from 04 to08 in a whole year The efficiency first decreased andthen increased with the turning point of the change atnoon The highest operating efficiency in these threeareas is in JuneThe lowest operating collector opticalefficiency is in December

(3) The shadowing losses are introduced by collectorshading during approximately the first and last 90

International Journal of Photoenergy 15

minutes of operation each day The end loss factorranged from 0985 to 1

(4) The optical efficiency of PTCs is mainly influencedby the incident angle of the sun shadowing effectand end loss effect are weak in the effect of opticalefficiency

(5) The annual optical efficiency of the parabolic troughsolar collector running in Lhasa is the highest in thesethree areas

The analytical method to performance simulation for theoptical efficiency of solar concentrator can be applied to otherconcentrated solar systems We are developing the programfor performance simulation for solar tower system in China

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

This study was simultaneously supported by the Key Labo-ratory Open Fund Project of Jiangsu Provincial Key Labo-ratory of Solar Energy Science and Technology (Grant noJPKLSST201504) and the Natural Science Foundation of theJiangsu Higher Education Institutions of China (Grant no14KJD470003)

References

[1] O Behar A Khellaf and K Mohammedi ldquoA review of studieson central receiver solar thermal power plantsrdquo Renewable andSustainable Energy Reviews vol 23 pp 12ndash39 2013

[2] A H Slocum D S Codd J Buongiorno et al ldquoConcentratedsolar power on demandrdquo Solar Energy vol 85 no 7 pp 1519ndash1529 2011

[3] H L Zhang J Baeyens J Degreve and G Caceres ldquoCon-centrated solar power plants review and design methodologyrdquoRenewable and Sustainable Energy Reviews vol 22 pp 466ndash4812013

[4] Office of the State Council of China ldquoStrategic action planfor energy development (2014ndash2020)rdquo 2014 (Chinese)httpwwwgovcnzhengcecontent2014-1119content 9222htm

[5] Dunhuang Energy Bureau Environmental Assessment Docu-ment for Dunhuang 10 MW of Solar Thermal Power Gen-eration Projects Dunhuang Energy Bureau 2015 (Chinese)httpwwwdunhuanggovcnReadNewsaspNewsID=16475

[6] A A Hachicha I Rodrıguez R Capdevila and A Oliva ldquoHeattransfer analysis and numerical simulation of a parabolic troughsolar collectorrdquoApplied Energy vol 111 no 11 pp 581ndash592 2013

[7] S A Kalogirou ldquoA detailed thermalmodel of a parabolic troughcollector receiverrdquo Energy vol 48 no 1 pp 298ndash306 2012

[8] H Muller-Steinhagen and F Trieb ldquolsquoConcentrating solarpowerrsquo A review of the technologyrdquo Quarterly of the RoyalAcademy of Engineering no 18 pp 43ndash50 2004

[9] A Fernandez-Garcıa E Zarza L Valenzuela and M PerezldquoParabolic-trough solar collectors and their applicationsrdquo

Renewable and Sustainable Energy Reviews vol 14 no 7 pp1695ndash1721 2010

[10] W Jinping W Jun Z Yaoming and B Xiaolong ldquoAnalysis ofheat transfer characteristics for parabolic trough solar collectorrdquoTransactions of the Chinese Society of Agricultural Engineeringvol 31 no 7 pp 185ndash192 2015 (Chinese)

[11] K M Knight S A Klein and J A Duffie ldquoA methodology forthe synthesis of hourly weather datardquo Solar Energy vol 46 no2 pp 109ndash120 1991

[12] M Petrakis H D Kambezidis S Lykoudis et al ldquoGeneration ofa lsquotypical meteorological yearrsquo for Nicosia Cyprusrdquo RenewableEnergy vol 13 no 3 pp 381ndash388 1998

[13] G Florides S Kalogirou K Theophilou et al ldquoAnalysis ofthe typical meteorological year (TMY) of Cyprus and houseload simulationrdquo in Proceedings of the 8th International IBPSAConference Eindhoven The Netherlands 2003

[14] J Garcıa-Barberena P GarciaM Sanchez et al ldquoAnalysis of theinfluence of operational strategies in plant performance usingSimulCET simulation software for parabolic trough powerplantsrdquo Solar Energy vol 86 no 1 pp 53ndash63 2012

[15] J Bonilla L J Yebra S Dormido and E Zarza ldquoParabolic-trough solar thermal power plant simulation scheme multi-objective genetic algorithm calibration and validationrdquo SolarEnergy vol 86 no 1 pp 531ndash540 2012

[16] P H Wagner and M Wittmann ldquoInfluence of different oper-ation strategies on transient solar thermal power plant simu-lation models with molten salt as heat transfer fluidrdquo EnergyProcedia vol 49 pp 1652ndash1663 2012

[17] W Huang P Hu and Z Chen ldquoPerformance simulation of aparabolic trough solar collectorrdquo Solar Energy vol 86 no 2 pp746ndash755 2012

[18] X Zhang W Xu T He et al ldquoSolar thermal system evaluationinChinardquo International Journal of Photoenergy vol 2015 ArticleID 163808 12 pages 2015

[19] W B Stine and R W Harrigan Solar Energy Fundamentalsand Design With Computer Applications John Wiley amp SonsHoboken NJ USA 1985

[20] W Jinping W Jun F Wei W Dengwen and Z YaomingldquoDevelopment and application of sun-tracking control systemfor parabolic trough solar collectorrdquo Transactions of the ChineseSociety of Agricultural Engineering vol 31 no 2 pp 45ndash52 2015

[21] R Dhanabal V Bharathi R Ranjitha A Ponni S Deepthi andP Mageshkannan ldquoComparison of efficiencies of solar trackersystems with static panel single-axis tracking system and dual-axis tracking system with fixed mountrdquo International Journal ofEngineering amp Technology vol 5 no 2 pp 1925ndash1933 2013

[22] CK Pandey andAKKatiyar ldquoAnote ondiffuse solar radiationon a tilted surfacerdquo Energy vol 34 no 11 pp 1764ndash1769 2009

[23] G Morin J Dersch W Platzer M Eck and A HaberleldquoComparison of linear Fresnel and parabolic trough collectorpower plantsrdquo Solar Energy vol 86 no 1 pp 1ndash12 2012

[24] K J Riffelmann ldquoComparison between PTR70 and UVACefficiency tests thermal loss measurements and Raytracingexperimentsrdquo Status Seminar vol 1 no 7 pp 187ndash197 2005

[25] F Lippke ldquoSimulation of the part load behaviour of a 30MW SEGS plantrdquo Tech Rep SAND95-1293 Sandia NationalLaboratories Albuquerque NM USA 1995

[26] V Dudley G Kolb M Sloan and D Kearney ldquoSEGS LS2solar collector test resultsrdquo Tech Rep SAND94-1884 SandiaNational Laboratories Albuquerque NM USA 1994

16 International Journal of Photoenergy

[27] M J Wagner and P Gilman ldquoTechnical manual for the SAMphysical trough modelrdquo Tech Rep Sandia National Laborato-ries Albuquerque NM USA 2011

[28] A M Patnode Simulation and performance evaluation ofparabolic trough solar power plants [Diss] University ofWisconsin-Madison Madison Wis USA 2006

[29] J Duffie and W Beckman Solar Engineering of Thermal Pro-cesses JohnWileyamp SonsHobokenNJUSA 3rd edition 2006

[30] M Ibanez Plana J Rosell Polo and J I Rosell Urrutia Tec-nologıa Solar Ediciones Mundi-Prensa Madrid Spain 2005

[31] B Bourges ldquoImprovement in solar declination computationrdquoSolar Energy vol 35 no 4 pp 367ndash369 1985

[32] httpwwwnrelgovcspsolarpacesproject detailcfmprojectID=33

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

4 International Journal of Photoenergy

timeThe relationship between solar time and standard timein hours is

119905sol = 119905st minus 119905ad +119871 st minus 119871 loc15+EOT60 (10)

where 119905st is on a standardmeridian for the local time zone 119905adis daylight saving time adjustment 119871 st is standard meridianfor the local time zone 119871 loc is the local meridian of thecollector site EOT is an equation of time that determines thedeviation in local time from solar time as a function of theday of the year the calculation process of equation of time isas follows [29]

EOT = 000096 + 00171856 cos119861 minus 02951084 sin119861

minus 0134458 cos (2119861) minus 0376188 sin (2119861) (11)

where

119861 = 0986 (119889 minus 1) (12)

where 119889 is the day number of the year (1 for January 1 365 forDecember 31)

The declination angle is [30]

120575119904= 2345 sin (28011 + 0984119889) (13)

When the declination angle and hour angle were calcu-lated the solar altitude and solar azimuth which are used todescribe the sun position can be computedThe solar azimuth(120572119904) and the solar altitude (120572) angles are calculated [31]

120572 = arcsin [sin 120575119904sin120601 + cos120601 cos 120575

119904cos120596]

120572119904= sign (120596)

10038161003816100381610038161003816100381610038161003816

arccos [cos (90 minus 120572) sin120601 minus sin 120575

119904

sin (90 minus 120572) cos120601]

10038161003816100381610038161003816100381610038161003816

(14)

where 120601 is the latitude

25 Calculation Flowchart The flowchart of the method forthe end losses factor shadowing factor cosine effect andoptical efficiency of the PTC system is shown in the blockdiagram in Figure 5 From the flowchart it can be seen that thesolar altitude is calculated according time latitude angle andday number inputs then solar azimuth and angle of incidenceare calculated The cosine effect incidence angle modifierand sun-tracking angle are calculated by using the angle ofincidence The factor for the end loss is calculated by usingthe angle of incidence focus length and length of PTC Thetotal efficiency can be obtained by using the results of theabove calculation and the tracking error mirror reflectanceand general error inputs

26 Model Validation The model can be validated bycomparing Patnodersquos test results in SEGS VI concentratingsolar power station (2005) [28] based on some typical testconditions shown in Table 1 [7] The station is located at35∘0101584051010158401015840 north 117∘33101584032010158401015840 west [32] To calculate theoptical efficiency of the parabolic trough concentrator usingthe model the power absorbed by the receiver of the PTC

Input time Input latitudeangle

Input day number

Calculatesolar time

angleCalculate

declinationangle

Calculatesolar altitude

Calculatesolar azimuth

Calculateangle of

incidence

Input trackingerror mirror

reflectance andgeneral error

End

Input focus length and

length of PTC

Calculateincidence

angle modifierCalculate

sun-trackingangle

Calculatecosine effect

Calculatefactor for the

shadow

Calculatefactor for the

end loss

Calculate thecollector optical

efficiency

Figure 5 Flowchart of calculating the end losses factor shadowingfactor cosine effect and optical efficiency

Table 1 Main parameters of SEGS VIrsquos PTC [7]

Parameters DataFocus length 14mAperture width 5mLength of collector 471mAbsorber tube diameter 70mmAbsorptance 097Aperture area 2355m2

Mirror reflectance 094

is calculated according to formula (4) calculation resultsare compared with the test data The comparisons betweenthe simulations and experiments are shown in Figure 6 Ascan be seen from Figure 6 the numerical results on theheat rate error are between 4 and 20Wm2 with a relativeerror range of 1 to the estimated values of 5 Calculationresults are compared with that of experiments it is found thatcalculation results are lower than experiment data the mainreason is that the tracking error is assumed to be a constantin this paper and many other parameters like the thermicfluid and materials of the collector are not considered andthe error is affected Overall as can be seen from Figure 6themathematical model of this paper can correctly reflect theoperating characteristics of PTCs

3 Results and Discussion in TypicalAreas of China

A typical parabolic trough solar collector with the receiverof the radius of envelope 012 meters was calculated The

International Journal of Photoenergy 5

Table 2 Parameters of the parabolic trough solar collector

Parameters DataFocus length 18mAperture width 575mLength of collector 100mRadius of envelope of receiver 012mRow space 15mGeometry effects 098Cleanliness factor 095Mirror reflectance 0935Tracking error 0994

Hea

t rat

e (W

m2)

18 2012 14 168 106Time (h)

0

200

400

600

800

1000

1200

0

200

400

600

800

1000

1200

Dire

ct N

orm

al Ir

radi

ance

(Wm

2)

DNIPatnodersquos test result This paper

Figure 6 Comparisons between themode and Patnodersquos test resultsfor validation

parameters for the collector were shown at Table 2 prototypeas shown in Figure 7

The parabolic trough solar collector with these param-eters has been designed by Jiangsu Provincial Key Labora-tory of Solar Energy Science and Technology as shown inFigure 7

The three typical regions of China were chosen as thecomputing sites which are Lhasa Tibet Delingha Qinghaiand Dunhuang Gansu geographic coordinates as shown inTable 3

The optical efficiency cosine factor solar shading factorend loss factor and annual average values at any time inthese three areas were compared with simulation studies andanalysis For the convenience the first days per month in ayear were chosen for performance simulation Figure 8 showsthe changing trend of the collector optical efficiency Theoptical efficiency of PTC changes from 04 to 08 in a wholeyear The efficiency first decreased and then increased withthe turning point of the change at noonThehighest operatingcollector optical efficiency is in June and the efficiency isrelatively higher from April to August The lowest operatingcollector optical efficiency is in December and the efficiencyis relatively lower and the difference of efficiency in these

Table 3 Computing sites

Regions Geographic coordinatesDelingha N 3737∘ E 9737∘

Dunhuang N 4015∘ E 9468∘

Lhasa N 2967∘ E 9113∘

Figure 7 A prototype of parabolic trough solar collector

three areas is also greater in January October andNovemberFrom Figure 8 it is evident that the optical efficiency of PTCsoperated in Lhasa is higher than in Delingha and the opticalefficiency of PTCs operated in Delingha is higher than inDunhuang As can be seen from formula (4) the differenceof operating optical efficiency in these three regions is mainlydetermined by collector cosine effect end loss factor andsolar shading factor The angle of incidence of the sun is theangle between the rays of the sun and the normal The solarincidence angle changes with the angle of the solar zenithangle and the azimuth angle

From Figure 9 we can see that the changing trend of thecollector cosine effect is basically the same as the trend ofthe optical efficiency From October to March the value ofthe cosine effect is larger ranging from 07 to 098 whileit is smaller in October November December and JanuaryThe cosine effect in Lhasa is larger than in Delingha and inDelingha it is larger than Dunhuang

Figure 10 shows the changing trend of collector end lossfactor End losses occur at the ends of the PTCs where for anonzero incidence angle some length of the absorber tube isnot illuminated by solar radiation reflected from the mirrorsThe collector end loss factor is mainly affected by tangentangle of incidence of the sun As it can be seen from the figurethat the end loss factor is lowest at noon every day except forJune and July the minimum value appeared at sunrise andsunset in June and July and the value is relatively close inMarch February and November in all the three areas whichranged from 0985 to 1 The end loss factors in Delingha andDelingha are basically the same the value in Lhasa is slightlylarger than the other two areas

Figure 11 shows changing trend of shadowing effect Inthis study the two adjacent PTCs are arranged in parallelrows with about 15m of spacing within each row PTCstrack the sun toward the east at sunrise and toward thewest at sunset Due to the low solar altitude angle of the

6 International Journal of Photoenergy

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Jan

colle

ctor

aver

age o

ptic

al effi

cien

cy

(a)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Feb

colle

ctor

aver

age o

ptic

al effi

cien

cy

(b)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Mar

colle

ctor

aver

age o

ptic

al effi

cien

cy

(c)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10Ap

r col

lect

or av

erag

e opt

ical

effici

ency

(d)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

May

colle

ctor

aver

age o

ptic

al effi

cien

cy

(e)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Jun

colle

ctor

aver

age o

ptic

al effi

cien

cy

(f)

Figure 8 Continued

International Journal of Photoenergy 7

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10Ju

l col

lect

or av

erag

e opt

ical

effici

ency

(g)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Aug

colle

ctor

aver

age o

ptic

al effi

cien

cy

(h)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Sep

colle

ctor

aver

age o

ptic

al effi

cien

cy

(i)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Oct

colle

ctor

aver

age o

ptic

al effi

cien

cy

(j)

DunhuangLhasaDelingha

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Nov

colle

ctor

aver

age o

ptic

al effi

cien

cy

(k)

DunhuangLhasaDelingha

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Dec

colle

ctor

aver

age o

ptic

al effi

cien

cy

(l)

Figure 8 Collector optical efficiency

sun in the morning the eastern-most row of collectors willreceive full sun but this row will shade all subsequent rowsto the west As the sun rises and the collectors track thesun this mutual row shading effect decreases until a criticalzenith angle is reached at which no row shading occurs

Collector rows remain unshaded through the middle of theday from late morning through early afternoon As seen inthe figure losses are introduced by collector shading duringapproximately the first and last 90 minutes of operationeach day Because the collectors are single axis tracking in

8 International Journal of Photoenergy

00

02

04

06

08

10

Jan

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a)

00

02

04

06

08

10

Feb

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(b)

00

02

04

06

08

10

Mar

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c)

00

02

04

06

08

10Ap

r col

lect

or co

sine e

ffect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d)

00

02

04

06

08

10

May

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(e)

00

02

04

06

08

10

Jun

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(f)

Figure 9 Continued

International Journal of Photoenergy 9

00

02

04

06

08

10Ju

l row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(g)

00

02

04

06

08

10

Aug

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(h)

00

02

04

06

08

10

Sep

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(i)

00

02

04

06

08

10

Oct

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(j)

DunhuangLhasaDelingha

00

02

04

06

08

10

Nov

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(k)

DunhuangLhasaDelingha

00

02

04

06

08

10

Dec

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(l)

Figure 9 Collector cosine effect

a north-south orientation the length of time over which rowshading occurs does not vary significantly throughout theyear

The annual values of the twelve days of the data werecalculated Figure 12 shows the annual values of cosine effect

shadowing effect end loss effect and optical efficiency Asit can be seen from the figure that annual optical efficiencyof Lhasa is greater than Delingha and the latter is greaterthanDunhuang the annual optical efficiency per hour duringthe day of the sunrise to the sunset for Lhasa is 496

10 International Journal of Photoenergy

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Jan

end

loss

effec

t

(a)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Feb

end

loss

effec

t

(b)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Mar

end

loss

effec

t

(c)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000Ap

r end

loss

effec

t

(d)

4 6 8 10 12Time of day (h)

14 16 18 20 22 240965

0970

0975

0980

0985

0990

0995

1000

May

end

loss

effec

t

(e)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Jun

end

loss

effec

t

(f)

Figure 10 Continued

International Journal of Photoenergy 11

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000Ju

l end

loss

effec

t

(g)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Aug

end

loss

effec

t

(h)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Sep

end

loss

effec

t

(i)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Oct

end

loss

effec

t

(j)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Nov

end

loss

effec

t

DunhuangLhasaDelingha

(k)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Dec

end

loss

effec

t

DunhuangLhasaDelingha

(l)

Figure 10 End loss factor

Delingha is 461 andDunhuang is 448The annual valuesof shadowing effect and shadowing effect are very large closeto 100The trend of annual cosine effect change is consistentwith the trend of optical efficiency which reveals that theoptical efficiency is mainly influenced by the incident angle

of the sun nevertheless shadowing effect and end loss effectare weak in the effect of optical efficiency

From the analysis above we conclude that the opticalefficiency of parabolic trough solar concentrator collectorsmainly by the impact of the incident angle of the sun

12 International Journal of Photoenergy

00

02

04

06

08

10

Jan

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a)

00

02

04

06

08

10

Feb

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(b)

00

02

04

06

08

10

Mar

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c)

00

02

04

06

08

10Ap

r row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d)

00

02

04

06

08

10

May

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(e)

00

02

04

06

08

10

Jun

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(f)

Figure 11 Continued

International Journal of Photoenergy 13

00

02

04

06

08

10Ju

l row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(g)

00

02

04

06

08

10

Aug

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(h)

00

02

04

06

08

10

Sep

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(i)

00

02

04

06

08

10

Oct

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(j)

00

02

04

06

08

10

Nov

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

DunhuangLhasaDelingha

(k)

00

02

04

06

08

10

Dec

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

DunhuangLhasaDelingha

(l)

Figure 11 Shadowing effect

shadowing effect and end loss effect are almost negligibleThe incident angle of the sun ismainly influenced by differentgeographic locations of parabolic trough solar concentratingcollector So the conclusion has important implications for

the sites selection of parabolic trough solar thermal powerplant

For Parabolic Trough Power Plants location choice fromLhasa Dunhuang and Delingha in China the optical

14 International Journal of Photoenergy

DunhuangLhasaDelingha

00

02

04

06

08

10

Ann

ual c

olle

ctor

aver

age o

ptic

al effi

cien

cy

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a) Annual collector average optical efficiency

DunhuangLhasaDelingha

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Ann

ual e

nd lo

ss eff

ect

(b) Annual end loss effect

DunhuangLhasaDelingha

00

02

04

06

08

10

Ann

ual r

ow sh

adow

ing

effec

t

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c) Annual row shadowing

DunhuangLhasaDelingha

00

02

04

06

08

10A

nnua

l col

lect

or co

sine e

ffect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d) Annual collector cosine effect

Figure 12 Annual values of cosine effect shadowing effect end loss effect and optical efficiency

efficiency of PTCs in Lhasa is higher than the other 2regions

4 Conclusions

In the paper the optical efficiency calculation method ofparabolic trough solar collector was used to analyze andstudy the performance of parabolic trough solar collectorat Dunhuang Delingha and Lhasa in China The first dayof every month during a year was chosen as a time ofcalculation mainly cosine effect shadowing effect end losseffect and optical efficiency were calculated

From PTCs in these three areas in China simulationresults some overall conclusions could be derived as follows

(1) In this paper a mathematical model of parabolictrough solar concentrator is established which isvalidated by comparing the test results in SEGS VIand performance simulation results can correctlyreflect the operating characteristics of PTCs

(2) The optical efficiency of PTC changes from 04 to08 in a whole year The efficiency first decreased andthen increased with the turning point of the change atnoon The highest operating efficiency in these threeareas is in JuneThe lowest operating collector opticalefficiency is in December

(3) The shadowing losses are introduced by collectorshading during approximately the first and last 90

International Journal of Photoenergy 15

minutes of operation each day The end loss factorranged from 0985 to 1

(4) The optical efficiency of PTCs is mainly influencedby the incident angle of the sun shadowing effectand end loss effect are weak in the effect of opticalefficiency

(5) The annual optical efficiency of the parabolic troughsolar collector running in Lhasa is the highest in thesethree areas

The analytical method to performance simulation for theoptical efficiency of solar concentrator can be applied to otherconcentrated solar systems We are developing the programfor performance simulation for solar tower system in China

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

This study was simultaneously supported by the Key Labo-ratory Open Fund Project of Jiangsu Provincial Key Labo-ratory of Solar Energy Science and Technology (Grant noJPKLSST201504) and the Natural Science Foundation of theJiangsu Higher Education Institutions of China (Grant no14KJD470003)

References

[1] O Behar A Khellaf and K Mohammedi ldquoA review of studieson central receiver solar thermal power plantsrdquo Renewable andSustainable Energy Reviews vol 23 pp 12ndash39 2013

[2] A H Slocum D S Codd J Buongiorno et al ldquoConcentratedsolar power on demandrdquo Solar Energy vol 85 no 7 pp 1519ndash1529 2011

[3] H L Zhang J Baeyens J Degreve and G Caceres ldquoCon-centrated solar power plants review and design methodologyrdquoRenewable and Sustainable Energy Reviews vol 22 pp 466ndash4812013

[4] Office of the State Council of China ldquoStrategic action planfor energy development (2014ndash2020)rdquo 2014 (Chinese)httpwwwgovcnzhengcecontent2014-1119content 9222htm

[5] Dunhuang Energy Bureau Environmental Assessment Docu-ment for Dunhuang 10 MW of Solar Thermal Power Gen-eration Projects Dunhuang Energy Bureau 2015 (Chinese)httpwwwdunhuanggovcnReadNewsaspNewsID=16475

[6] A A Hachicha I Rodrıguez R Capdevila and A Oliva ldquoHeattransfer analysis and numerical simulation of a parabolic troughsolar collectorrdquoApplied Energy vol 111 no 11 pp 581ndash592 2013

[7] S A Kalogirou ldquoA detailed thermalmodel of a parabolic troughcollector receiverrdquo Energy vol 48 no 1 pp 298ndash306 2012

[8] H Muller-Steinhagen and F Trieb ldquolsquoConcentrating solarpowerrsquo A review of the technologyrdquo Quarterly of the RoyalAcademy of Engineering no 18 pp 43ndash50 2004

[9] A Fernandez-Garcıa E Zarza L Valenzuela and M PerezldquoParabolic-trough solar collectors and their applicationsrdquo

Renewable and Sustainable Energy Reviews vol 14 no 7 pp1695ndash1721 2010

[10] W Jinping W Jun Z Yaoming and B Xiaolong ldquoAnalysis ofheat transfer characteristics for parabolic trough solar collectorrdquoTransactions of the Chinese Society of Agricultural Engineeringvol 31 no 7 pp 185ndash192 2015 (Chinese)

[11] K M Knight S A Klein and J A Duffie ldquoA methodology forthe synthesis of hourly weather datardquo Solar Energy vol 46 no2 pp 109ndash120 1991

[12] M Petrakis H D Kambezidis S Lykoudis et al ldquoGeneration ofa lsquotypical meteorological yearrsquo for Nicosia Cyprusrdquo RenewableEnergy vol 13 no 3 pp 381ndash388 1998

[13] G Florides S Kalogirou K Theophilou et al ldquoAnalysis ofthe typical meteorological year (TMY) of Cyprus and houseload simulationrdquo in Proceedings of the 8th International IBPSAConference Eindhoven The Netherlands 2003

[14] J Garcıa-Barberena P GarciaM Sanchez et al ldquoAnalysis of theinfluence of operational strategies in plant performance usingSimulCET simulation software for parabolic trough powerplantsrdquo Solar Energy vol 86 no 1 pp 53ndash63 2012

[15] J Bonilla L J Yebra S Dormido and E Zarza ldquoParabolic-trough solar thermal power plant simulation scheme multi-objective genetic algorithm calibration and validationrdquo SolarEnergy vol 86 no 1 pp 531ndash540 2012

[16] P H Wagner and M Wittmann ldquoInfluence of different oper-ation strategies on transient solar thermal power plant simu-lation models with molten salt as heat transfer fluidrdquo EnergyProcedia vol 49 pp 1652ndash1663 2012

[17] W Huang P Hu and Z Chen ldquoPerformance simulation of aparabolic trough solar collectorrdquo Solar Energy vol 86 no 2 pp746ndash755 2012

[18] X Zhang W Xu T He et al ldquoSolar thermal system evaluationinChinardquo International Journal of Photoenergy vol 2015 ArticleID 163808 12 pages 2015

[19] W B Stine and R W Harrigan Solar Energy Fundamentalsand Design With Computer Applications John Wiley amp SonsHoboken NJ USA 1985

[20] W Jinping W Jun F Wei W Dengwen and Z YaomingldquoDevelopment and application of sun-tracking control systemfor parabolic trough solar collectorrdquo Transactions of the ChineseSociety of Agricultural Engineering vol 31 no 2 pp 45ndash52 2015

[21] R Dhanabal V Bharathi R Ranjitha A Ponni S Deepthi andP Mageshkannan ldquoComparison of efficiencies of solar trackersystems with static panel single-axis tracking system and dual-axis tracking system with fixed mountrdquo International Journal ofEngineering amp Technology vol 5 no 2 pp 1925ndash1933 2013

[22] CK Pandey andAKKatiyar ldquoAnote ondiffuse solar radiationon a tilted surfacerdquo Energy vol 34 no 11 pp 1764ndash1769 2009

[23] G Morin J Dersch W Platzer M Eck and A HaberleldquoComparison of linear Fresnel and parabolic trough collectorpower plantsrdquo Solar Energy vol 86 no 1 pp 1ndash12 2012

[24] K J Riffelmann ldquoComparison between PTR70 and UVACefficiency tests thermal loss measurements and Raytracingexperimentsrdquo Status Seminar vol 1 no 7 pp 187ndash197 2005

[25] F Lippke ldquoSimulation of the part load behaviour of a 30MW SEGS plantrdquo Tech Rep SAND95-1293 Sandia NationalLaboratories Albuquerque NM USA 1995

[26] V Dudley G Kolb M Sloan and D Kearney ldquoSEGS LS2solar collector test resultsrdquo Tech Rep SAND94-1884 SandiaNational Laboratories Albuquerque NM USA 1994

16 International Journal of Photoenergy

[27] M J Wagner and P Gilman ldquoTechnical manual for the SAMphysical trough modelrdquo Tech Rep Sandia National Laborato-ries Albuquerque NM USA 2011

[28] A M Patnode Simulation and performance evaluation ofparabolic trough solar power plants [Diss] University ofWisconsin-Madison Madison Wis USA 2006

[29] J Duffie and W Beckman Solar Engineering of Thermal Pro-cesses JohnWileyamp SonsHobokenNJUSA 3rd edition 2006

[30] M Ibanez Plana J Rosell Polo and J I Rosell Urrutia Tec-nologıa Solar Ediciones Mundi-Prensa Madrid Spain 2005

[31] B Bourges ldquoImprovement in solar declination computationrdquoSolar Energy vol 35 no 4 pp 367ndash369 1985

[32] httpwwwnrelgovcspsolarpacesproject detailcfmprojectID=33

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

International Journal of Photoenergy 5

Table 2 Parameters of the parabolic trough solar collector

Parameters DataFocus length 18mAperture width 575mLength of collector 100mRadius of envelope of receiver 012mRow space 15mGeometry effects 098Cleanliness factor 095Mirror reflectance 0935Tracking error 0994

Hea

t rat

e (W

m2)

18 2012 14 168 106Time (h)

0

200

400

600

800

1000

1200

0

200

400

600

800

1000

1200

Dire

ct N

orm

al Ir

radi

ance

(Wm

2)

DNIPatnodersquos test result This paper

Figure 6 Comparisons between themode and Patnodersquos test resultsfor validation

parameters for the collector were shown at Table 2 prototypeas shown in Figure 7

The parabolic trough solar collector with these param-eters has been designed by Jiangsu Provincial Key Labora-tory of Solar Energy Science and Technology as shown inFigure 7

The three typical regions of China were chosen as thecomputing sites which are Lhasa Tibet Delingha Qinghaiand Dunhuang Gansu geographic coordinates as shown inTable 3

The optical efficiency cosine factor solar shading factorend loss factor and annual average values at any time inthese three areas were compared with simulation studies andanalysis For the convenience the first days per month in ayear were chosen for performance simulation Figure 8 showsthe changing trend of the collector optical efficiency Theoptical efficiency of PTC changes from 04 to 08 in a wholeyear The efficiency first decreased and then increased withthe turning point of the change at noonThehighest operatingcollector optical efficiency is in June and the efficiency isrelatively higher from April to August The lowest operatingcollector optical efficiency is in December and the efficiencyis relatively lower and the difference of efficiency in these

Table 3 Computing sites

Regions Geographic coordinatesDelingha N 3737∘ E 9737∘

Dunhuang N 4015∘ E 9468∘

Lhasa N 2967∘ E 9113∘

Figure 7 A prototype of parabolic trough solar collector

three areas is also greater in January October andNovemberFrom Figure 8 it is evident that the optical efficiency of PTCsoperated in Lhasa is higher than in Delingha and the opticalefficiency of PTCs operated in Delingha is higher than inDunhuang As can be seen from formula (4) the differenceof operating optical efficiency in these three regions is mainlydetermined by collector cosine effect end loss factor andsolar shading factor The angle of incidence of the sun is theangle between the rays of the sun and the normal The solarincidence angle changes with the angle of the solar zenithangle and the azimuth angle

From Figure 9 we can see that the changing trend of thecollector cosine effect is basically the same as the trend ofthe optical efficiency From October to March the value ofthe cosine effect is larger ranging from 07 to 098 whileit is smaller in October November December and JanuaryThe cosine effect in Lhasa is larger than in Delingha and inDelingha it is larger than Dunhuang

Figure 10 shows the changing trend of collector end lossfactor End losses occur at the ends of the PTCs where for anonzero incidence angle some length of the absorber tube isnot illuminated by solar radiation reflected from the mirrorsThe collector end loss factor is mainly affected by tangentangle of incidence of the sun As it can be seen from the figurethat the end loss factor is lowest at noon every day except forJune and July the minimum value appeared at sunrise andsunset in June and July and the value is relatively close inMarch February and November in all the three areas whichranged from 0985 to 1 The end loss factors in Delingha andDelingha are basically the same the value in Lhasa is slightlylarger than the other two areas

Figure 11 shows changing trend of shadowing effect Inthis study the two adjacent PTCs are arranged in parallelrows with about 15m of spacing within each row PTCstrack the sun toward the east at sunrise and toward thewest at sunset Due to the low solar altitude angle of the

6 International Journal of Photoenergy

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Jan

colle

ctor

aver

age o

ptic

al effi

cien

cy

(a)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Feb

colle

ctor

aver

age o

ptic

al effi

cien

cy

(b)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Mar

colle

ctor

aver

age o

ptic

al effi

cien

cy

(c)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10Ap

r col

lect

or av

erag

e opt

ical

effici

ency

(d)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

May

colle

ctor

aver

age o

ptic

al effi

cien

cy

(e)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Jun

colle

ctor

aver

age o

ptic

al effi

cien

cy

(f)

Figure 8 Continued

International Journal of Photoenergy 7

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10Ju

l col

lect

or av

erag

e opt

ical

effici

ency

(g)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Aug

colle

ctor

aver

age o

ptic

al effi

cien

cy

(h)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Sep

colle

ctor

aver

age o

ptic

al effi

cien

cy

(i)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Oct

colle

ctor

aver

age o

ptic

al effi

cien

cy

(j)

DunhuangLhasaDelingha

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Nov

colle

ctor

aver

age o

ptic

al effi

cien

cy

(k)

DunhuangLhasaDelingha

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Dec

colle

ctor

aver

age o

ptic

al effi

cien

cy

(l)

Figure 8 Collector optical efficiency

sun in the morning the eastern-most row of collectors willreceive full sun but this row will shade all subsequent rowsto the west As the sun rises and the collectors track thesun this mutual row shading effect decreases until a criticalzenith angle is reached at which no row shading occurs

Collector rows remain unshaded through the middle of theday from late morning through early afternoon As seen inthe figure losses are introduced by collector shading duringapproximately the first and last 90 minutes of operationeach day Because the collectors are single axis tracking in

8 International Journal of Photoenergy

00

02

04

06

08

10

Jan

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a)

00

02

04

06

08

10

Feb

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(b)

00

02

04

06

08

10

Mar

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c)

00

02

04

06

08

10Ap

r col

lect

or co

sine e

ffect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d)

00

02

04

06

08

10

May

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(e)

00

02

04

06

08

10

Jun

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(f)

Figure 9 Continued

International Journal of Photoenergy 9

00

02

04

06

08

10Ju

l row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(g)

00

02

04

06

08

10

Aug

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(h)

00

02

04

06

08

10

Sep

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(i)

00

02

04

06

08

10

Oct

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(j)

DunhuangLhasaDelingha

00

02

04

06

08

10

Nov

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(k)

DunhuangLhasaDelingha

00

02

04

06

08

10

Dec

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(l)

Figure 9 Collector cosine effect

a north-south orientation the length of time over which rowshading occurs does not vary significantly throughout theyear

The annual values of the twelve days of the data werecalculated Figure 12 shows the annual values of cosine effect

shadowing effect end loss effect and optical efficiency Asit can be seen from the figure that annual optical efficiencyof Lhasa is greater than Delingha and the latter is greaterthanDunhuang the annual optical efficiency per hour duringthe day of the sunrise to the sunset for Lhasa is 496

10 International Journal of Photoenergy

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Jan

end

loss

effec

t

(a)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Feb

end

loss

effec

t

(b)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Mar

end

loss

effec

t

(c)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000Ap

r end

loss

effec

t

(d)

4 6 8 10 12Time of day (h)

14 16 18 20 22 240965

0970

0975

0980

0985

0990

0995

1000

May

end

loss

effec

t

(e)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Jun

end

loss

effec

t

(f)

Figure 10 Continued

International Journal of Photoenergy 11

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000Ju

l end

loss

effec

t

(g)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Aug

end

loss

effec

t

(h)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Sep

end

loss

effec

t

(i)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Oct

end

loss

effec

t

(j)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Nov

end

loss

effec

t

DunhuangLhasaDelingha

(k)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Dec

end

loss

effec

t

DunhuangLhasaDelingha

(l)

Figure 10 End loss factor

Delingha is 461 andDunhuang is 448The annual valuesof shadowing effect and shadowing effect are very large closeto 100The trend of annual cosine effect change is consistentwith the trend of optical efficiency which reveals that theoptical efficiency is mainly influenced by the incident angle

of the sun nevertheless shadowing effect and end loss effectare weak in the effect of optical efficiency

From the analysis above we conclude that the opticalefficiency of parabolic trough solar concentrator collectorsmainly by the impact of the incident angle of the sun

12 International Journal of Photoenergy

00

02

04

06

08

10

Jan

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a)

00

02

04

06

08

10

Feb

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(b)

00

02

04

06

08

10

Mar

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c)

00

02

04

06

08

10Ap

r row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d)

00

02

04

06

08

10

May

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(e)

00

02

04

06

08

10

Jun

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(f)

Figure 11 Continued

International Journal of Photoenergy 13

00

02

04

06

08

10Ju

l row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(g)

00

02

04

06

08

10

Aug

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(h)

00

02

04

06

08

10

Sep

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(i)

00

02

04

06

08

10

Oct

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(j)

00

02

04

06

08

10

Nov

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

DunhuangLhasaDelingha

(k)

00

02

04

06

08

10

Dec

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

DunhuangLhasaDelingha

(l)

Figure 11 Shadowing effect

shadowing effect and end loss effect are almost negligibleThe incident angle of the sun ismainly influenced by differentgeographic locations of parabolic trough solar concentratingcollector So the conclusion has important implications for

the sites selection of parabolic trough solar thermal powerplant

For Parabolic Trough Power Plants location choice fromLhasa Dunhuang and Delingha in China the optical

14 International Journal of Photoenergy

DunhuangLhasaDelingha

00

02

04

06

08

10

Ann

ual c

olle

ctor

aver

age o

ptic

al effi

cien

cy

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a) Annual collector average optical efficiency

DunhuangLhasaDelingha

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Ann

ual e

nd lo

ss eff

ect

(b) Annual end loss effect

DunhuangLhasaDelingha

00

02

04

06

08

10

Ann

ual r

ow sh

adow

ing

effec

t

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c) Annual row shadowing

DunhuangLhasaDelingha

00

02

04

06

08

10A

nnua

l col

lect

or co

sine e

ffect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d) Annual collector cosine effect

Figure 12 Annual values of cosine effect shadowing effect end loss effect and optical efficiency

efficiency of PTCs in Lhasa is higher than the other 2regions

4 Conclusions

In the paper the optical efficiency calculation method ofparabolic trough solar collector was used to analyze andstudy the performance of parabolic trough solar collectorat Dunhuang Delingha and Lhasa in China The first dayof every month during a year was chosen as a time ofcalculation mainly cosine effect shadowing effect end losseffect and optical efficiency were calculated

From PTCs in these three areas in China simulationresults some overall conclusions could be derived as follows

(1) In this paper a mathematical model of parabolictrough solar concentrator is established which isvalidated by comparing the test results in SEGS VIand performance simulation results can correctlyreflect the operating characteristics of PTCs

(2) The optical efficiency of PTC changes from 04 to08 in a whole year The efficiency first decreased andthen increased with the turning point of the change atnoon The highest operating efficiency in these threeareas is in JuneThe lowest operating collector opticalefficiency is in December

(3) The shadowing losses are introduced by collectorshading during approximately the first and last 90

International Journal of Photoenergy 15

minutes of operation each day The end loss factorranged from 0985 to 1

(4) The optical efficiency of PTCs is mainly influencedby the incident angle of the sun shadowing effectand end loss effect are weak in the effect of opticalefficiency

(5) The annual optical efficiency of the parabolic troughsolar collector running in Lhasa is the highest in thesethree areas

The analytical method to performance simulation for theoptical efficiency of solar concentrator can be applied to otherconcentrated solar systems We are developing the programfor performance simulation for solar tower system in China

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

This study was simultaneously supported by the Key Labo-ratory Open Fund Project of Jiangsu Provincial Key Labo-ratory of Solar Energy Science and Technology (Grant noJPKLSST201504) and the Natural Science Foundation of theJiangsu Higher Education Institutions of China (Grant no14KJD470003)

References

[1] O Behar A Khellaf and K Mohammedi ldquoA review of studieson central receiver solar thermal power plantsrdquo Renewable andSustainable Energy Reviews vol 23 pp 12ndash39 2013

[2] A H Slocum D S Codd J Buongiorno et al ldquoConcentratedsolar power on demandrdquo Solar Energy vol 85 no 7 pp 1519ndash1529 2011

[3] H L Zhang J Baeyens J Degreve and G Caceres ldquoCon-centrated solar power plants review and design methodologyrdquoRenewable and Sustainable Energy Reviews vol 22 pp 466ndash4812013

[4] Office of the State Council of China ldquoStrategic action planfor energy development (2014ndash2020)rdquo 2014 (Chinese)httpwwwgovcnzhengcecontent2014-1119content 9222htm

[5] Dunhuang Energy Bureau Environmental Assessment Docu-ment for Dunhuang 10 MW of Solar Thermal Power Gen-eration Projects Dunhuang Energy Bureau 2015 (Chinese)httpwwwdunhuanggovcnReadNewsaspNewsID=16475

[6] A A Hachicha I Rodrıguez R Capdevila and A Oliva ldquoHeattransfer analysis and numerical simulation of a parabolic troughsolar collectorrdquoApplied Energy vol 111 no 11 pp 581ndash592 2013

[7] S A Kalogirou ldquoA detailed thermalmodel of a parabolic troughcollector receiverrdquo Energy vol 48 no 1 pp 298ndash306 2012

[8] H Muller-Steinhagen and F Trieb ldquolsquoConcentrating solarpowerrsquo A review of the technologyrdquo Quarterly of the RoyalAcademy of Engineering no 18 pp 43ndash50 2004

[9] A Fernandez-Garcıa E Zarza L Valenzuela and M PerezldquoParabolic-trough solar collectors and their applicationsrdquo

Renewable and Sustainable Energy Reviews vol 14 no 7 pp1695ndash1721 2010

[10] W Jinping W Jun Z Yaoming and B Xiaolong ldquoAnalysis ofheat transfer characteristics for parabolic trough solar collectorrdquoTransactions of the Chinese Society of Agricultural Engineeringvol 31 no 7 pp 185ndash192 2015 (Chinese)

[11] K M Knight S A Klein and J A Duffie ldquoA methodology forthe synthesis of hourly weather datardquo Solar Energy vol 46 no2 pp 109ndash120 1991

[12] M Petrakis H D Kambezidis S Lykoudis et al ldquoGeneration ofa lsquotypical meteorological yearrsquo for Nicosia Cyprusrdquo RenewableEnergy vol 13 no 3 pp 381ndash388 1998

[13] G Florides S Kalogirou K Theophilou et al ldquoAnalysis ofthe typical meteorological year (TMY) of Cyprus and houseload simulationrdquo in Proceedings of the 8th International IBPSAConference Eindhoven The Netherlands 2003

[14] J Garcıa-Barberena P GarciaM Sanchez et al ldquoAnalysis of theinfluence of operational strategies in plant performance usingSimulCET simulation software for parabolic trough powerplantsrdquo Solar Energy vol 86 no 1 pp 53ndash63 2012

[15] J Bonilla L J Yebra S Dormido and E Zarza ldquoParabolic-trough solar thermal power plant simulation scheme multi-objective genetic algorithm calibration and validationrdquo SolarEnergy vol 86 no 1 pp 531ndash540 2012

[16] P H Wagner and M Wittmann ldquoInfluence of different oper-ation strategies on transient solar thermal power plant simu-lation models with molten salt as heat transfer fluidrdquo EnergyProcedia vol 49 pp 1652ndash1663 2012

[17] W Huang P Hu and Z Chen ldquoPerformance simulation of aparabolic trough solar collectorrdquo Solar Energy vol 86 no 2 pp746ndash755 2012

[18] X Zhang W Xu T He et al ldquoSolar thermal system evaluationinChinardquo International Journal of Photoenergy vol 2015 ArticleID 163808 12 pages 2015

[19] W B Stine and R W Harrigan Solar Energy Fundamentalsand Design With Computer Applications John Wiley amp SonsHoboken NJ USA 1985

[20] W Jinping W Jun F Wei W Dengwen and Z YaomingldquoDevelopment and application of sun-tracking control systemfor parabolic trough solar collectorrdquo Transactions of the ChineseSociety of Agricultural Engineering vol 31 no 2 pp 45ndash52 2015

[21] R Dhanabal V Bharathi R Ranjitha A Ponni S Deepthi andP Mageshkannan ldquoComparison of efficiencies of solar trackersystems with static panel single-axis tracking system and dual-axis tracking system with fixed mountrdquo International Journal ofEngineering amp Technology vol 5 no 2 pp 1925ndash1933 2013

[22] CK Pandey andAKKatiyar ldquoAnote ondiffuse solar radiationon a tilted surfacerdquo Energy vol 34 no 11 pp 1764ndash1769 2009

[23] G Morin J Dersch W Platzer M Eck and A HaberleldquoComparison of linear Fresnel and parabolic trough collectorpower plantsrdquo Solar Energy vol 86 no 1 pp 1ndash12 2012

[24] K J Riffelmann ldquoComparison between PTR70 and UVACefficiency tests thermal loss measurements and Raytracingexperimentsrdquo Status Seminar vol 1 no 7 pp 187ndash197 2005

[25] F Lippke ldquoSimulation of the part load behaviour of a 30MW SEGS plantrdquo Tech Rep SAND95-1293 Sandia NationalLaboratories Albuquerque NM USA 1995

[26] V Dudley G Kolb M Sloan and D Kearney ldquoSEGS LS2solar collector test resultsrdquo Tech Rep SAND94-1884 SandiaNational Laboratories Albuquerque NM USA 1994

16 International Journal of Photoenergy

[27] M J Wagner and P Gilman ldquoTechnical manual for the SAMphysical trough modelrdquo Tech Rep Sandia National Laborato-ries Albuquerque NM USA 2011

[28] A M Patnode Simulation and performance evaluation ofparabolic trough solar power plants [Diss] University ofWisconsin-Madison Madison Wis USA 2006

[29] J Duffie and W Beckman Solar Engineering of Thermal Pro-cesses JohnWileyamp SonsHobokenNJUSA 3rd edition 2006

[30] M Ibanez Plana J Rosell Polo and J I Rosell Urrutia Tec-nologıa Solar Ediciones Mundi-Prensa Madrid Spain 2005

[31] B Bourges ldquoImprovement in solar declination computationrdquoSolar Energy vol 35 no 4 pp 367ndash369 1985

[32] httpwwwnrelgovcspsolarpacesproject detailcfmprojectID=33

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

6 International Journal of Photoenergy

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Jan

colle

ctor

aver

age o

ptic

al effi

cien

cy

(a)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Feb

colle

ctor

aver

age o

ptic

al effi

cien

cy

(b)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Mar

colle

ctor

aver

age o

ptic

al effi

cien

cy

(c)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10Ap

r col

lect

or av

erag

e opt

ical

effici

ency

(d)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

May

colle

ctor

aver

age o

ptic

al effi

cien

cy

(e)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Jun

colle

ctor

aver

age o

ptic

al effi

cien

cy

(f)

Figure 8 Continued

International Journal of Photoenergy 7

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10Ju

l col

lect

or av

erag

e opt

ical

effici

ency

(g)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Aug

colle

ctor

aver

age o

ptic

al effi

cien

cy

(h)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Sep

colle

ctor

aver

age o

ptic

al effi

cien

cy

(i)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Oct

colle

ctor

aver

age o

ptic

al effi

cien

cy

(j)

DunhuangLhasaDelingha

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Nov

colle

ctor

aver

age o

ptic

al effi

cien

cy

(k)

DunhuangLhasaDelingha

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Dec

colle

ctor

aver

age o

ptic

al effi

cien

cy

(l)

Figure 8 Collector optical efficiency

sun in the morning the eastern-most row of collectors willreceive full sun but this row will shade all subsequent rowsto the west As the sun rises and the collectors track thesun this mutual row shading effect decreases until a criticalzenith angle is reached at which no row shading occurs

Collector rows remain unshaded through the middle of theday from late morning through early afternoon As seen inthe figure losses are introduced by collector shading duringapproximately the first and last 90 minutes of operationeach day Because the collectors are single axis tracking in

8 International Journal of Photoenergy

00

02

04

06

08

10

Jan

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a)

00

02

04

06

08

10

Feb

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(b)

00

02

04

06

08

10

Mar

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c)

00

02

04

06

08

10Ap

r col

lect

or co

sine e

ffect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d)

00

02

04

06

08

10

May

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(e)

00

02

04

06

08

10

Jun

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(f)

Figure 9 Continued

International Journal of Photoenergy 9

00

02

04

06

08

10Ju

l row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(g)

00

02

04

06

08

10

Aug

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(h)

00

02

04

06

08

10

Sep

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(i)

00

02

04

06

08

10

Oct

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(j)

DunhuangLhasaDelingha

00

02

04

06

08

10

Nov

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(k)

DunhuangLhasaDelingha

00

02

04

06

08

10

Dec

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(l)

Figure 9 Collector cosine effect

a north-south orientation the length of time over which rowshading occurs does not vary significantly throughout theyear

The annual values of the twelve days of the data werecalculated Figure 12 shows the annual values of cosine effect

shadowing effect end loss effect and optical efficiency Asit can be seen from the figure that annual optical efficiencyof Lhasa is greater than Delingha and the latter is greaterthanDunhuang the annual optical efficiency per hour duringthe day of the sunrise to the sunset for Lhasa is 496

10 International Journal of Photoenergy

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Jan

end

loss

effec

t

(a)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Feb

end

loss

effec

t

(b)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Mar

end

loss

effec

t

(c)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000Ap

r end

loss

effec

t

(d)

4 6 8 10 12Time of day (h)

14 16 18 20 22 240965

0970

0975

0980

0985

0990

0995

1000

May

end

loss

effec

t

(e)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Jun

end

loss

effec

t

(f)

Figure 10 Continued

International Journal of Photoenergy 11

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000Ju

l end

loss

effec

t

(g)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Aug

end

loss

effec

t

(h)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Sep

end

loss

effec

t

(i)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Oct

end

loss

effec

t

(j)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Nov

end

loss

effec

t

DunhuangLhasaDelingha

(k)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Dec

end

loss

effec

t

DunhuangLhasaDelingha

(l)

Figure 10 End loss factor

Delingha is 461 andDunhuang is 448The annual valuesof shadowing effect and shadowing effect are very large closeto 100The trend of annual cosine effect change is consistentwith the trend of optical efficiency which reveals that theoptical efficiency is mainly influenced by the incident angle

of the sun nevertheless shadowing effect and end loss effectare weak in the effect of optical efficiency

From the analysis above we conclude that the opticalefficiency of parabolic trough solar concentrator collectorsmainly by the impact of the incident angle of the sun

12 International Journal of Photoenergy

00

02

04

06

08

10

Jan

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a)

00

02

04

06

08

10

Feb

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(b)

00

02

04

06

08

10

Mar

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c)

00

02

04

06

08

10Ap

r row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d)

00

02

04

06

08

10

May

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(e)

00

02

04

06

08

10

Jun

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(f)

Figure 11 Continued

International Journal of Photoenergy 13

00

02

04

06

08

10Ju

l row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(g)

00

02

04

06

08

10

Aug

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(h)

00

02

04

06

08

10

Sep

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(i)

00

02

04

06

08

10

Oct

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(j)

00

02

04

06

08

10

Nov

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

DunhuangLhasaDelingha

(k)

00

02

04

06

08

10

Dec

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

DunhuangLhasaDelingha

(l)

Figure 11 Shadowing effect

shadowing effect and end loss effect are almost negligibleThe incident angle of the sun ismainly influenced by differentgeographic locations of parabolic trough solar concentratingcollector So the conclusion has important implications for

the sites selection of parabolic trough solar thermal powerplant

For Parabolic Trough Power Plants location choice fromLhasa Dunhuang and Delingha in China the optical

14 International Journal of Photoenergy

DunhuangLhasaDelingha

00

02

04

06

08

10

Ann

ual c

olle

ctor

aver

age o

ptic

al effi

cien

cy

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a) Annual collector average optical efficiency

DunhuangLhasaDelingha

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Ann

ual e

nd lo

ss eff

ect

(b) Annual end loss effect

DunhuangLhasaDelingha

00

02

04

06

08

10

Ann

ual r

ow sh

adow

ing

effec

t

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c) Annual row shadowing

DunhuangLhasaDelingha

00

02

04

06

08

10A

nnua

l col

lect

or co

sine e

ffect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d) Annual collector cosine effect

Figure 12 Annual values of cosine effect shadowing effect end loss effect and optical efficiency

efficiency of PTCs in Lhasa is higher than the other 2regions

4 Conclusions

In the paper the optical efficiency calculation method ofparabolic trough solar collector was used to analyze andstudy the performance of parabolic trough solar collectorat Dunhuang Delingha and Lhasa in China The first dayof every month during a year was chosen as a time ofcalculation mainly cosine effect shadowing effect end losseffect and optical efficiency were calculated

From PTCs in these three areas in China simulationresults some overall conclusions could be derived as follows

(1) In this paper a mathematical model of parabolictrough solar concentrator is established which isvalidated by comparing the test results in SEGS VIand performance simulation results can correctlyreflect the operating characteristics of PTCs

(2) The optical efficiency of PTC changes from 04 to08 in a whole year The efficiency first decreased andthen increased with the turning point of the change atnoon The highest operating efficiency in these threeareas is in JuneThe lowest operating collector opticalefficiency is in December

(3) The shadowing losses are introduced by collectorshading during approximately the first and last 90

International Journal of Photoenergy 15

minutes of operation each day The end loss factorranged from 0985 to 1

(4) The optical efficiency of PTCs is mainly influencedby the incident angle of the sun shadowing effectand end loss effect are weak in the effect of opticalefficiency

(5) The annual optical efficiency of the parabolic troughsolar collector running in Lhasa is the highest in thesethree areas

The analytical method to performance simulation for theoptical efficiency of solar concentrator can be applied to otherconcentrated solar systems We are developing the programfor performance simulation for solar tower system in China

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

This study was simultaneously supported by the Key Labo-ratory Open Fund Project of Jiangsu Provincial Key Labo-ratory of Solar Energy Science and Technology (Grant noJPKLSST201504) and the Natural Science Foundation of theJiangsu Higher Education Institutions of China (Grant no14KJD470003)

References

[1] O Behar A Khellaf and K Mohammedi ldquoA review of studieson central receiver solar thermal power plantsrdquo Renewable andSustainable Energy Reviews vol 23 pp 12ndash39 2013

[2] A H Slocum D S Codd J Buongiorno et al ldquoConcentratedsolar power on demandrdquo Solar Energy vol 85 no 7 pp 1519ndash1529 2011

[3] H L Zhang J Baeyens J Degreve and G Caceres ldquoCon-centrated solar power plants review and design methodologyrdquoRenewable and Sustainable Energy Reviews vol 22 pp 466ndash4812013

[4] Office of the State Council of China ldquoStrategic action planfor energy development (2014ndash2020)rdquo 2014 (Chinese)httpwwwgovcnzhengcecontent2014-1119content 9222htm

[5] Dunhuang Energy Bureau Environmental Assessment Docu-ment for Dunhuang 10 MW of Solar Thermal Power Gen-eration Projects Dunhuang Energy Bureau 2015 (Chinese)httpwwwdunhuanggovcnReadNewsaspNewsID=16475

[6] A A Hachicha I Rodrıguez R Capdevila and A Oliva ldquoHeattransfer analysis and numerical simulation of a parabolic troughsolar collectorrdquoApplied Energy vol 111 no 11 pp 581ndash592 2013

[7] S A Kalogirou ldquoA detailed thermalmodel of a parabolic troughcollector receiverrdquo Energy vol 48 no 1 pp 298ndash306 2012

[8] H Muller-Steinhagen and F Trieb ldquolsquoConcentrating solarpowerrsquo A review of the technologyrdquo Quarterly of the RoyalAcademy of Engineering no 18 pp 43ndash50 2004

[9] A Fernandez-Garcıa E Zarza L Valenzuela and M PerezldquoParabolic-trough solar collectors and their applicationsrdquo

Renewable and Sustainable Energy Reviews vol 14 no 7 pp1695ndash1721 2010

[10] W Jinping W Jun Z Yaoming and B Xiaolong ldquoAnalysis ofheat transfer characteristics for parabolic trough solar collectorrdquoTransactions of the Chinese Society of Agricultural Engineeringvol 31 no 7 pp 185ndash192 2015 (Chinese)

[11] K M Knight S A Klein and J A Duffie ldquoA methodology forthe synthesis of hourly weather datardquo Solar Energy vol 46 no2 pp 109ndash120 1991

[12] M Petrakis H D Kambezidis S Lykoudis et al ldquoGeneration ofa lsquotypical meteorological yearrsquo for Nicosia Cyprusrdquo RenewableEnergy vol 13 no 3 pp 381ndash388 1998

[13] G Florides S Kalogirou K Theophilou et al ldquoAnalysis ofthe typical meteorological year (TMY) of Cyprus and houseload simulationrdquo in Proceedings of the 8th International IBPSAConference Eindhoven The Netherlands 2003

[14] J Garcıa-Barberena P GarciaM Sanchez et al ldquoAnalysis of theinfluence of operational strategies in plant performance usingSimulCET simulation software for parabolic trough powerplantsrdquo Solar Energy vol 86 no 1 pp 53ndash63 2012

[15] J Bonilla L J Yebra S Dormido and E Zarza ldquoParabolic-trough solar thermal power plant simulation scheme multi-objective genetic algorithm calibration and validationrdquo SolarEnergy vol 86 no 1 pp 531ndash540 2012

[16] P H Wagner and M Wittmann ldquoInfluence of different oper-ation strategies on transient solar thermal power plant simu-lation models with molten salt as heat transfer fluidrdquo EnergyProcedia vol 49 pp 1652ndash1663 2012

[17] W Huang P Hu and Z Chen ldquoPerformance simulation of aparabolic trough solar collectorrdquo Solar Energy vol 86 no 2 pp746ndash755 2012

[18] X Zhang W Xu T He et al ldquoSolar thermal system evaluationinChinardquo International Journal of Photoenergy vol 2015 ArticleID 163808 12 pages 2015

[19] W B Stine and R W Harrigan Solar Energy Fundamentalsand Design With Computer Applications John Wiley amp SonsHoboken NJ USA 1985

[20] W Jinping W Jun F Wei W Dengwen and Z YaomingldquoDevelopment and application of sun-tracking control systemfor parabolic trough solar collectorrdquo Transactions of the ChineseSociety of Agricultural Engineering vol 31 no 2 pp 45ndash52 2015

[21] R Dhanabal V Bharathi R Ranjitha A Ponni S Deepthi andP Mageshkannan ldquoComparison of efficiencies of solar trackersystems with static panel single-axis tracking system and dual-axis tracking system with fixed mountrdquo International Journal ofEngineering amp Technology vol 5 no 2 pp 1925ndash1933 2013

[22] CK Pandey andAKKatiyar ldquoAnote ondiffuse solar radiationon a tilted surfacerdquo Energy vol 34 no 11 pp 1764ndash1769 2009

[23] G Morin J Dersch W Platzer M Eck and A HaberleldquoComparison of linear Fresnel and parabolic trough collectorpower plantsrdquo Solar Energy vol 86 no 1 pp 1ndash12 2012

[24] K J Riffelmann ldquoComparison between PTR70 and UVACefficiency tests thermal loss measurements and Raytracingexperimentsrdquo Status Seminar vol 1 no 7 pp 187ndash197 2005

[25] F Lippke ldquoSimulation of the part load behaviour of a 30MW SEGS plantrdquo Tech Rep SAND95-1293 Sandia NationalLaboratories Albuquerque NM USA 1995

[26] V Dudley G Kolb M Sloan and D Kearney ldquoSEGS LS2solar collector test resultsrdquo Tech Rep SAND94-1884 SandiaNational Laboratories Albuquerque NM USA 1994

16 International Journal of Photoenergy

[27] M J Wagner and P Gilman ldquoTechnical manual for the SAMphysical trough modelrdquo Tech Rep Sandia National Laborato-ries Albuquerque NM USA 2011

[28] A M Patnode Simulation and performance evaluation ofparabolic trough solar power plants [Diss] University ofWisconsin-Madison Madison Wis USA 2006

[29] J Duffie and W Beckman Solar Engineering of Thermal Pro-cesses JohnWileyamp SonsHobokenNJUSA 3rd edition 2006

[30] M Ibanez Plana J Rosell Polo and J I Rosell Urrutia Tec-nologıa Solar Ediciones Mundi-Prensa Madrid Spain 2005

[31] B Bourges ldquoImprovement in solar declination computationrdquoSolar Energy vol 35 no 4 pp 367ndash369 1985

[32] httpwwwnrelgovcspsolarpacesproject detailcfmprojectID=33

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

International Journal of Photoenergy 7

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10Ju

l col

lect

or av

erag

e opt

ical

effici

ency

(g)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Aug

colle

ctor

aver

age o

ptic

al effi

cien

cy

(h)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Sep

colle

ctor

aver

age o

ptic

al effi

cien

cy

(i)

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Oct

colle

ctor

aver

age o

ptic

al effi

cien

cy

(j)

DunhuangLhasaDelingha

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Nov

colle

ctor

aver

age o

ptic

al effi

cien

cy

(k)

DunhuangLhasaDelingha

6 8 10 12 14 16 18 20 22 244Time of day (h)

00

02

04

06

08

10

Dec

colle

ctor

aver

age o

ptic

al effi

cien

cy

(l)

Figure 8 Collector optical efficiency

sun in the morning the eastern-most row of collectors willreceive full sun but this row will shade all subsequent rowsto the west As the sun rises and the collectors track thesun this mutual row shading effect decreases until a criticalzenith angle is reached at which no row shading occurs

Collector rows remain unshaded through the middle of theday from late morning through early afternoon As seen inthe figure losses are introduced by collector shading duringapproximately the first and last 90 minutes of operationeach day Because the collectors are single axis tracking in

8 International Journal of Photoenergy

00

02

04

06

08

10

Jan

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a)

00

02

04

06

08

10

Feb

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(b)

00

02

04

06

08

10

Mar

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c)

00

02

04

06

08

10Ap

r col

lect

or co

sine e

ffect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d)

00

02

04

06

08

10

May

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(e)

00

02

04

06

08

10

Jun

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(f)

Figure 9 Continued

International Journal of Photoenergy 9

00

02

04

06

08

10Ju

l row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(g)

00

02

04

06

08

10

Aug

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(h)

00

02

04

06

08

10

Sep

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(i)

00

02

04

06

08

10

Oct

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(j)

DunhuangLhasaDelingha

00

02

04

06

08

10

Nov

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(k)

DunhuangLhasaDelingha

00

02

04

06

08

10

Dec

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(l)

Figure 9 Collector cosine effect

a north-south orientation the length of time over which rowshading occurs does not vary significantly throughout theyear

The annual values of the twelve days of the data werecalculated Figure 12 shows the annual values of cosine effect

shadowing effect end loss effect and optical efficiency Asit can be seen from the figure that annual optical efficiencyof Lhasa is greater than Delingha and the latter is greaterthanDunhuang the annual optical efficiency per hour duringthe day of the sunrise to the sunset for Lhasa is 496

10 International Journal of Photoenergy

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Jan

end

loss

effec

t

(a)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Feb

end

loss

effec

t

(b)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Mar

end

loss

effec

t

(c)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000Ap

r end

loss

effec

t

(d)

4 6 8 10 12Time of day (h)

14 16 18 20 22 240965

0970

0975

0980

0985

0990

0995

1000

May

end

loss

effec

t

(e)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Jun

end

loss

effec

t

(f)

Figure 10 Continued

International Journal of Photoenergy 11

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000Ju

l end

loss

effec

t

(g)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Aug

end

loss

effec

t

(h)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Sep

end

loss

effec

t

(i)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Oct

end

loss

effec

t

(j)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Nov

end

loss

effec

t

DunhuangLhasaDelingha

(k)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Dec

end

loss

effec

t

DunhuangLhasaDelingha

(l)

Figure 10 End loss factor

Delingha is 461 andDunhuang is 448The annual valuesof shadowing effect and shadowing effect are very large closeto 100The trend of annual cosine effect change is consistentwith the trend of optical efficiency which reveals that theoptical efficiency is mainly influenced by the incident angle

of the sun nevertheless shadowing effect and end loss effectare weak in the effect of optical efficiency

From the analysis above we conclude that the opticalefficiency of parabolic trough solar concentrator collectorsmainly by the impact of the incident angle of the sun

12 International Journal of Photoenergy

00

02

04

06

08

10

Jan

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a)

00

02

04

06

08

10

Feb

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(b)

00

02

04

06

08

10

Mar

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c)

00

02

04

06

08

10Ap

r row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d)

00

02

04

06

08

10

May

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(e)

00

02

04

06

08

10

Jun

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(f)

Figure 11 Continued

International Journal of Photoenergy 13

00

02

04

06

08

10Ju

l row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(g)

00

02

04

06

08

10

Aug

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(h)

00

02

04

06

08

10

Sep

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(i)

00

02

04

06

08

10

Oct

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(j)

00

02

04

06

08

10

Nov

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

DunhuangLhasaDelingha

(k)

00

02

04

06

08

10

Dec

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

DunhuangLhasaDelingha

(l)

Figure 11 Shadowing effect

shadowing effect and end loss effect are almost negligibleThe incident angle of the sun ismainly influenced by differentgeographic locations of parabolic trough solar concentratingcollector So the conclusion has important implications for

the sites selection of parabolic trough solar thermal powerplant

For Parabolic Trough Power Plants location choice fromLhasa Dunhuang and Delingha in China the optical

14 International Journal of Photoenergy

DunhuangLhasaDelingha

00

02

04

06

08

10

Ann

ual c

olle

ctor

aver

age o

ptic

al effi

cien

cy

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a) Annual collector average optical efficiency

DunhuangLhasaDelingha

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Ann

ual e

nd lo

ss eff

ect

(b) Annual end loss effect

DunhuangLhasaDelingha

00

02

04

06

08

10

Ann

ual r

ow sh

adow

ing

effec

t

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c) Annual row shadowing

DunhuangLhasaDelingha

00

02

04

06

08

10A

nnua

l col

lect

or co

sine e

ffect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d) Annual collector cosine effect

Figure 12 Annual values of cosine effect shadowing effect end loss effect and optical efficiency

efficiency of PTCs in Lhasa is higher than the other 2regions

4 Conclusions

In the paper the optical efficiency calculation method ofparabolic trough solar collector was used to analyze andstudy the performance of parabolic trough solar collectorat Dunhuang Delingha and Lhasa in China The first dayof every month during a year was chosen as a time ofcalculation mainly cosine effect shadowing effect end losseffect and optical efficiency were calculated

From PTCs in these three areas in China simulationresults some overall conclusions could be derived as follows

(1) In this paper a mathematical model of parabolictrough solar concentrator is established which isvalidated by comparing the test results in SEGS VIand performance simulation results can correctlyreflect the operating characteristics of PTCs

(2) The optical efficiency of PTC changes from 04 to08 in a whole year The efficiency first decreased andthen increased with the turning point of the change atnoon The highest operating efficiency in these threeareas is in JuneThe lowest operating collector opticalefficiency is in December

(3) The shadowing losses are introduced by collectorshading during approximately the first and last 90

International Journal of Photoenergy 15

minutes of operation each day The end loss factorranged from 0985 to 1

(4) The optical efficiency of PTCs is mainly influencedby the incident angle of the sun shadowing effectand end loss effect are weak in the effect of opticalefficiency

(5) The annual optical efficiency of the parabolic troughsolar collector running in Lhasa is the highest in thesethree areas

The analytical method to performance simulation for theoptical efficiency of solar concentrator can be applied to otherconcentrated solar systems We are developing the programfor performance simulation for solar tower system in China

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

This study was simultaneously supported by the Key Labo-ratory Open Fund Project of Jiangsu Provincial Key Labo-ratory of Solar Energy Science and Technology (Grant noJPKLSST201504) and the Natural Science Foundation of theJiangsu Higher Education Institutions of China (Grant no14KJD470003)

References

[1] O Behar A Khellaf and K Mohammedi ldquoA review of studieson central receiver solar thermal power plantsrdquo Renewable andSustainable Energy Reviews vol 23 pp 12ndash39 2013

[2] A H Slocum D S Codd J Buongiorno et al ldquoConcentratedsolar power on demandrdquo Solar Energy vol 85 no 7 pp 1519ndash1529 2011

[3] H L Zhang J Baeyens J Degreve and G Caceres ldquoCon-centrated solar power plants review and design methodologyrdquoRenewable and Sustainable Energy Reviews vol 22 pp 466ndash4812013

[4] Office of the State Council of China ldquoStrategic action planfor energy development (2014ndash2020)rdquo 2014 (Chinese)httpwwwgovcnzhengcecontent2014-1119content 9222htm

[5] Dunhuang Energy Bureau Environmental Assessment Docu-ment for Dunhuang 10 MW of Solar Thermal Power Gen-eration Projects Dunhuang Energy Bureau 2015 (Chinese)httpwwwdunhuanggovcnReadNewsaspNewsID=16475

[6] A A Hachicha I Rodrıguez R Capdevila and A Oliva ldquoHeattransfer analysis and numerical simulation of a parabolic troughsolar collectorrdquoApplied Energy vol 111 no 11 pp 581ndash592 2013

[7] S A Kalogirou ldquoA detailed thermalmodel of a parabolic troughcollector receiverrdquo Energy vol 48 no 1 pp 298ndash306 2012

[8] H Muller-Steinhagen and F Trieb ldquolsquoConcentrating solarpowerrsquo A review of the technologyrdquo Quarterly of the RoyalAcademy of Engineering no 18 pp 43ndash50 2004

[9] A Fernandez-Garcıa E Zarza L Valenzuela and M PerezldquoParabolic-trough solar collectors and their applicationsrdquo

Renewable and Sustainable Energy Reviews vol 14 no 7 pp1695ndash1721 2010

[10] W Jinping W Jun Z Yaoming and B Xiaolong ldquoAnalysis ofheat transfer characteristics for parabolic trough solar collectorrdquoTransactions of the Chinese Society of Agricultural Engineeringvol 31 no 7 pp 185ndash192 2015 (Chinese)

[11] K M Knight S A Klein and J A Duffie ldquoA methodology forthe synthesis of hourly weather datardquo Solar Energy vol 46 no2 pp 109ndash120 1991

[12] M Petrakis H D Kambezidis S Lykoudis et al ldquoGeneration ofa lsquotypical meteorological yearrsquo for Nicosia Cyprusrdquo RenewableEnergy vol 13 no 3 pp 381ndash388 1998

[13] G Florides S Kalogirou K Theophilou et al ldquoAnalysis ofthe typical meteorological year (TMY) of Cyprus and houseload simulationrdquo in Proceedings of the 8th International IBPSAConference Eindhoven The Netherlands 2003

[14] J Garcıa-Barberena P GarciaM Sanchez et al ldquoAnalysis of theinfluence of operational strategies in plant performance usingSimulCET simulation software for parabolic trough powerplantsrdquo Solar Energy vol 86 no 1 pp 53ndash63 2012

[15] J Bonilla L J Yebra S Dormido and E Zarza ldquoParabolic-trough solar thermal power plant simulation scheme multi-objective genetic algorithm calibration and validationrdquo SolarEnergy vol 86 no 1 pp 531ndash540 2012

[16] P H Wagner and M Wittmann ldquoInfluence of different oper-ation strategies on transient solar thermal power plant simu-lation models with molten salt as heat transfer fluidrdquo EnergyProcedia vol 49 pp 1652ndash1663 2012

[17] W Huang P Hu and Z Chen ldquoPerformance simulation of aparabolic trough solar collectorrdquo Solar Energy vol 86 no 2 pp746ndash755 2012

[18] X Zhang W Xu T He et al ldquoSolar thermal system evaluationinChinardquo International Journal of Photoenergy vol 2015 ArticleID 163808 12 pages 2015

[19] W B Stine and R W Harrigan Solar Energy Fundamentalsand Design With Computer Applications John Wiley amp SonsHoboken NJ USA 1985

[20] W Jinping W Jun F Wei W Dengwen and Z YaomingldquoDevelopment and application of sun-tracking control systemfor parabolic trough solar collectorrdquo Transactions of the ChineseSociety of Agricultural Engineering vol 31 no 2 pp 45ndash52 2015

[21] R Dhanabal V Bharathi R Ranjitha A Ponni S Deepthi andP Mageshkannan ldquoComparison of efficiencies of solar trackersystems with static panel single-axis tracking system and dual-axis tracking system with fixed mountrdquo International Journal ofEngineering amp Technology vol 5 no 2 pp 1925ndash1933 2013

[22] CK Pandey andAKKatiyar ldquoAnote ondiffuse solar radiationon a tilted surfacerdquo Energy vol 34 no 11 pp 1764ndash1769 2009

[23] G Morin J Dersch W Platzer M Eck and A HaberleldquoComparison of linear Fresnel and parabolic trough collectorpower plantsrdquo Solar Energy vol 86 no 1 pp 1ndash12 2012

[24] K J Riffelmann ldquoComparison between PTR70 and UVACefficiency tests thermal loss measurements and Raytracingexperimentsrdquo Status Seminar vol 1 no 7 pp 187ndash197 2005

[25] F Lippke ldquoSimulation of the part load behaviour of a 30MW SEGS plantrdquo Tech Rep SAND95-1293 Sandia NationalLaboratories Albuquerque NM USA 1995

[26] V Dudley G Kolb M Sloan and D Kearney ldquoSEGS LS2solar collector test resultsrdquo Tech Rep SAND94-1884 SandiaNational Laboratories Albuquerque NM USA 1994

16 International Journal of Photoenergy

[27] M J Wagner and P Gilman ldquoTechnical manual for the SAMphysical trough modelrdquo Tech Rep Sandia National Laborato-ries Albuquerque NM USA 2011

[28] A M Patnode Simulation and performance evaluation ofparabolic trough solar power plants [Diss] University ofWisconsin-Madison Madison Wis USA 2006

[29] J Duffie and W Beckman Solar Engineering of Thermal Pro-cesses JohnWileyamp SonsHobokenNJUSA 3rd edition 2006

[30] M Ibanez Plana J Rosell Polo and J I Rosell Urrutia Tec-nologıa Solar Ediciones Mundi-Prensa Madrid Spain 2005

[31] B Bourges ldquoImprovement in solar declination computationrdquoSolar Energy vol 35 no 4 pp 367ndash369 1985

[32] httpwwwnrelgovcspsolarpacesproject detailcfmprojectID=33

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

8 International Journal of Photoenergy

00

02

04

06

08

10

Jan

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a)

00

02

04

06

08

10

Feb

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(b)

00

02

04

06

08

10

Mar

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c)

00

02

04

06

08

10Ap

r col

lect

or co

sine e

ffect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d)

00

02

04

06

08

10

May

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(e)

00

02

04

06

08

10

Jun

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(f)

Figure 9 Continued

International Journal of Photoenergy 9

00

02

04

06

08

10Ju

l row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(g)

00

02

04

06

08

10

Aug

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(h)

00

02

04

06

08

10

Sep

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(i)

00

02

04

06

08

10

Oct

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(j)

DunhuangLhasaDelingha

00

02

04

06

08

10

Nov

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(k)

DunhuangLhasaDelingha

00

02

04

06

08

10

Dec

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(l)

Figure 9 Collector cosine effect

a north-south orientation the length of time over which rowshading occurs does not vary significantly throughout theyear

The annual values of the twelve days of the data werecalculated Figure 12 shows the annual values of cosine effect

shadowing effect end loss effect and optical efficiency Asit can be seen from the figure that annual optical efficiencyof Lhasa is greater than Delingha and the latter is greaterthanDunhuang the annual optical efficiency per hour duringthe day of the sunrise to the sunset for Lhasa is 496

10 International Journal of Photoenergy

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Jan

end

loss

effec

t

(a)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Feb

end

loss

effec

t

(b)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Mar

end

loss

effec

t

(c)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000Ap

r end

loss

effec

t

(d)

4 6 8 10 12Time of day (h)

14 16 18 20 22 240965

0970

0975

0980

0985

0990

0995

1000

May

end

loss

effec

t

(e)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Jun

end

loss

effec

t

(f)

Figure 10 Continued

International Journal of Photoenergy 11

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000Ju

l end

loss

effec

t

(g)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Aug

end

loss

effec

t

(h)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Sep

end

loss

effec

t

(i)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Oct

end

loss

effec

t

(j)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Nov

end

loss

effec

t

DunhuangLhasaDelingha

(k)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Dec

end

loss

effec

t

DunhuangLhasaDelingha

(l)

Figure 10 End loss factor

Delingha is 461 andDunhuang is 448The annual valuesof shadowing effect and shadowing effect are very large closeto 100The trend of annual cosine effect change is consistentwith the trend of optical efficiency which reveals that theoptical efficiency is mainly influenced by the incident angle

of the sun nevertheless shadowing effect and end loss effectare weak in the effect of optical efficiency

From the analysis above we conclude that the opticalefficiency of parabolic trough solar concentrator collectorsmainly by the impact of the incident angle of the sun

12 International Journal of Photoenergy

00

02

04

06

08

10

Jan

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a)

00

02

04

06

08

10

Feb

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(b)

00

02

04

06

08

10

Mar

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c)

00

02

04

06

08

10Ap

r row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d)

00

02

04

06

08

10

May

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(e)

00

02

04

06

08

10

Jun

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(f)

Figure 11 Continued

International Journal of Photoenergy 13

00

02

04

06

08

10Ju

l row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(g)

00

02

04

06

08

10

Aug

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(h)

00

02

04

06

08

10

Sep

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(i)

00

02

04

06

08

10

Oct

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(j)

00

02

04

06

08

10

Nov

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

DunhuangLhasaDelingha

(k)

00

02

04

06

08

10

Dec

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

DunhuangLhasaDelingha

(l)

Figure 11 Shadowing effect

shadowing effect and end loss effect are almost negligibleThe incident angle of the sun ismainly influenced by differentgeographic locations of parabolic trough solar concentratingcollector So the conclusion has important implications for

the sites selection of parabolic trough solar thermal powerplant

For Parabolic Trough Power Plants location choice fromLhasa Dunhuang and Delingha in China the optical

14 International Journal of Photoenergy

DunhuangLhasaDelingha

00

02

04

06

08

10

Ann

ual c

olle

ctor

aver

age o

ptic

al effi

cien

cy

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a) Annual collector average optical efficiency

DunhuangLhasaDelingha

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Ann

ual e

nd lo

ss eff

ect

(b) Annual end loss effect

DunhuangLhasaDelingha

00

02

04

06

08

10

Ann

ual r

ow sh

adow

ing

effec

t

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c) Annual row shadowing

DunhuangLhasaDelingha

00

02

04

06

08

10A

nnua

l col

lect

or co

sine e

ffect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d) Annual collector cosine effect

Figure 12 Annual values of cosine effect shadowing effect end loss effect and optical efficiency

efficiency of PTCs in Lhasa is higher than the other 2regions

4 Conclusions

In the paper the optical efficiency calculation method ofparabolic trough solar collector was used to analyze andstudy the performance of parabolic trough solar collectorat Dunhuang Delingha and Lhasa in China The first dayof every month during a year was chosen as a time ofcalculation mainly cosine effect shadowing effect end losseffect and optical efficiency were calculated

From PTCs in these three areas in China simulationresults some overall conclusions could be derived as follows

(1) In this paper a mathematical model of parabolictrough solar concentrator is established which isvalidated by comparing the test results in SEGS VIand performance simulation results can correctlyreflect the operating characteristics of PTCs

(2) The optical efficiency of PTC changes from 04 to08 in a whole year The efficiency first decreased andthen increased with the turning point of the change atnoon The highest operating efficiency in these threeareas is in JuneThe lowest operating collector opticalefficiency is in December

(3) The shadowing losses are introduced by collectorshading during approximately the first and last 90

International Journal of Photoenergy 15

minutes of operation each day The end loss factorranged from 0985 to 1

(4) The optical efficiency of PTCs is mainly influencedby the incident angle of the sun shadowing effectand end loss effect are weak in the effect of opticalefficiency

(5) The annual optical efficiency of the parabolic troughsolar collector running in Lhasa is the highest in thesethree areas

The analytical method to performance simulation for theoptical efficiency of solar concentrator can be applied to otherconcentrated solar systems We are developing the programfor performance simulation for solar tower system in China

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

This study was simultaneously supported by the Key Labo-ratory Open Fund Project of Jiangsu Provincial Key Labo-ratory of Solar Energy Science and Technology (Grant noJPKLSST201504) and the Natural Science Foundation of theJiangsu Higher Education Institutions of China (Grant no14KJD470003)

References

[1] O Behar A Khellaf and K Mohammedi ldquoA review of studieson central receiver solar thermal power plantsrdquo Renewable andSustainable Energy Reviews vol 23 pp 12ndash39 2013

[2] A H Slocum D S Codd J Buongiorno et al ldquoConcentratedsolar power on demandrdquo Solar Energy vol 85 no 7 pp 1519ndash1529 2011

[3] H L Zhang J Baeyens J Degreve and G Caceres ldquoCon-centrated solar power plants review and design methodologyrdquoRenewable and Sustainable Energy Reviews vol 22 pp 466ndash4812013

[4] Office of the State Council of China ldquoStrategic action planfor energy development (2014ndash2020)rdquo 2014 (Chinese)httpwwwgovcnzhengcecontent2014-1119content 9222htm

[5] Dunhuang Energy Bureau Environmental Assessment Docu-ment for Dunhuang 10 MW of Solar Thermal Power Gen-eration Projects Dunhuang Energy Bureau 2015 (Chinese)httpwwwdunhuanggovcnReadNewsaspNewsID=16475

[6] A A Hachicha I Rodrıguez R Capdevila and A Oliva ldquoHeattransfer analysis and numerical simulation of a parabolic troughsolar collectorrdquoApplied Energy vol 111 no 11 pp 581ndash592 2013

[7] S A Kalogirou ldquoA detailed thermalmodel of a parabolic troughcollector receiverrdquo Energy vol 48 no 1 pp 298ndash306 2012

[8] H Muller-Steinhagen and F Trieb ldquolsquoConcentrating solarpowerrsquo A review of the technologyrdquo Quarterly of the RoyalAcademy of Engineering no 18 pp 43ndash50 2004

[9] A Fernandez-Garcıa E Zarza L Valenzuela and M PerezldquoParabolic-trough solar collectors and their applicationsrdquo

Renewable and Sustainable Energy Reviews vol 14 no 7 pp1695ndash1721 2010

[10] W Jinping W Jun Z Yaoming and B Xiaolong ldquoAnalysis ofheat transfer characteristics for parabolic trough solar collectorrdquoTransactions of the Chinese Society of Agricultural Engineeringvol 31 no 7 pp 185ndash192 2015 (Chinese)

[11] K M Knight S A Klein and J A Duffie ldquoA methodology forthe synthesis of hourly weather datardquo Solar Energy vol 46 no2 pp 109ndash120 1991

[12] M Petrakis H D Kambezidis S Lykoudis et al ldquoGeneration ofa lsquotypical meteorological yearrsquo for Nicosia Cyprusrdquo RenewableEnergy vol 13 no 3 pp 381ndash388 1998

[13] G Florides S Kalogirou K Theophilou et al ldquoAnalysis ofthe typical meteorological year (TMY) of Cyprus and houseload simulationrdquo in Proceedings of the 8th International IBPSAConference Eindhoven The Netherlands 2003

[14] J Garcıa-Barberena P GarciaM Sanchez et al ldquoAnalysis of theinfluence of operational strategies in plant performance usingSimulCET simulation software for parabolic trough powerplantsrdquo Solar Energy vol 86 no 1 pp 53ndash63 2012

[15] J Bonilla L J Yebra S Dormido and E Zarza ldquoParabolic-trough solar thermal power plant simulation scheme multi-objective genetic algorithm calibration and validationrdquo SolarEnergy vol 86 no 1 pp 531ndash540 2012

[16] P H Wagner and M Wittmann ldquoInfluence of different oper-ation strategies on transient solar thermal power plant simu-lation models with molten salt as heat transfer fluidrdquo EnergyProcedia vol 49 pp 1652ndash1663 2012

[17] W Huang P Hu and Z Chen ldquoPerformance simulation of aparabolic trough solar collectorrdquo Solar Energy vol 86 no 2 pp746ndash755 2012

[18] X Zhang W Xu T He et al ldquoSolar thermal system evaluationinChinardquo International Journal of Photoenergy vol 2015 ArticleID 163808 12 pages 2015

[19] W B Stine and R W Harrigan Solar Energy Fundamentalsand Design With Computer Applications John Wiley amp SonsHoboken NJ USA 1985

[20] W Jinping W Jun F Wei W Dengwen and Z YaomingldquoDevelopment and application of sun-tracking control systemfor parabolic trough solar collectorrdquo Transactions of the ChineseSociety of Agricultural Engineering vol 31 no 2 pp 45ndash52 2015

[21] R Dhanabal V Bharathi R Ranjitha A Ponni S Deepthi andP Mageshkannan ldquoComparison of efficiencies of solar trackersystems with static panel single-axis tracking system and dual-axis tracking system with fixed mountrdquo International Journal ofEngineering amp Technology vol 5 no 2 pp 1925ndash1933 2013

[22] CK Pandey andAKKatiyar ldquoAnote ondiffuse solar radiationon a tilted surfacerdquo Energy vol 34 no 11 pp 1764ndash1769 2009

[23] G Morin J Dersch W Platzer M Eck and A HaberleldquoComparison of linear Fresnel and parabolic trough collectorpower plantsrdquo Solar Energy vol 86 no 1 pp 1ndash12 2012

[24] K J Riffelmann ldquoComparison between PTR70 and UVACefficiency tests thermal loss measurements and Raytracingexperimentsrdquo Status Seminar vol 1 no 7 pp 187ndash197 2005

[25] F Lippke ldquoSimulation of the part load behaviour of a 30MW SEGS plantrdquo Tech Rep SAND95-1293 Sandia NationalLaboratories Albuquerque NM USA 1995

[26] V Dudley G Kolb M Sloan and D Kearney ldquoSEGS LS2solar collector test resultsrdquo Tech Rep SAND94-1884 SandiaNational Laboratories Albuquerque NM USA 1994

16 International Journal of Photoenergy

[27] M J Wagner and P Gilman ldquoTechnical manual for the SAMphysical trough modelrdquo Tech Rep Sandia National Laborato-ries Albuquerque NM USA 2011

[28] A M Patnode Simulation and performance evaluation ofparabolic trough solar power plants [Diss] University ofWisconsin-Madison Madison Wis USA 2006

[29] J Duffie and W Beckman Solar Engineering of Thermal Pro-cesses JohnWileyamp SonsHobokenNJUSA 3rd edition 2006

[30] M Ibanez Plana J Rosell Polo and J I Rosell Urrutia Tec-nologıa Solar Ediciones Mundi-Prensa Madrid Spain 2005

[31] B Bourges ldquoImprovement in solar declination computationrdquoSolar Energy vol 35 no 4 pp 367ndash369 1985

[32] httpwwwnrelgovcspsolarpacesproject detailcfmprojectID=33

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

International Journal of Photoenergy 9

00

02

04

06

08

10Ju

l row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(g)

00

02

04

06

08

10

Aug

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(h)

00

02

04

06

08

10

Sep

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(i)

00

02

04

06

08

10

Oct

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(j)

DunhuangLhasaDelingha

00

02

04

06

08

10

Nov

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(k)

DunhuangLhasaDelingha

00

02

04

06

08

10

Dec

colle

ctor

cosin

e effe

ct

6 8 10 12 14 16 18 20 22 244Time of day (h)

(l)

Figure 9 Collector cosine effect

a north-south orientation the length of time over which rowshading occurs does not vary significantly throughout theyear

The annual values of the twelve days of the data werecalculated Figure 12 shows the annual values of cosine effect

shadowing effect end loss effect and optical efficiency Asit can be seen from the figure that annual optical efficiencyof Lhasa is greater than Delingha and the latter is greaterthanDunhuang the annual optical efficiency per hour duringthe day of the sunrise to the sunset for Lhasa is 496

10 International Journal of Photoenergy

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Jan

end

loss

effec

t

(a)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Feb

end

loss

effec

t

(b)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Mar

end

loss

effec

t

(c)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000Ap

r end

loss

effec

t

(d)

4 6 8 10 12Time of day (h)

14 16 18 20 22 240965

0970

0975

0980

0985

0990

0995

1000

May

end

loss

effec

t

(e)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Jun

end

loss

effec

t

(f)

Figure 10 Continued

International Journal of Photoenergy 11

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000Ju

l end

loss

effec

t

(g)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Aug

end

loss

effec

t

(h)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Sep

end

loss

effec

t

(i)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Oct

end

loss

effec

t

(j)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Nov

end

loss

effec

t

DunhuangLhasaDelingha

(k)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Dec

end

loss

effec

t

DunhuangLhasaDelingha

(l)

Figure 10 End loss factor

Delingha is 461 andDunhuang is 448The annual valuesof shadowing effect and shadowing effect are very large closeto 100The trend of annual cosine effect change is consistentwith the trend of optical efficiency which reveals that theoptical efficiency is mainly influenced by the incident angle

of the sun nevertheless shadowing effect and end loss effectare weak in the effect of optical efficiency

From the analysis above we conclude that the opticalefficiency of parabolic trough solar concentrator collectorsmainly by the impact of the incident angle of the sun

12 International Journal of Photoenergy

00

02

04

06

08

10

Jan

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a)

00

02

04

06

08

10

Feb

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(b)

00

02

04

06

08

10

Mar

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c)

00

02

04

06

08

10Ap

r row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d)

00

02

04

06

08

10

May

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(e)

00

02

04

06

08

10

Jun

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(f)

Figure 11 Continued

International Journal of Photoenergy 13

00

02

04

06

08

10Ju

l row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(g)

00

02

04

06

08

10

Aug

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(h)

00

02

04

06

08

10

Sep

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(i)

00

02

04

06

08

10

Oct

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(j)

00

02

04

06

08

10

Nov

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

DunhuangLhasaDelingha

(k)

00

02

04

06

08

10

Dec

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

DunhuangLhasaDelingha

(l)

Figure 11 Shadowing effect

shadowing effect and end loss effect are almost negligibleThe incident angle of the sun ismainly influenced by differentgeographic locations of parabolic trough solar concentratingcollector So the conclusion has important implications for

the sites selection of parabolic trough solar thermal powerplant

For Parabolic Trough Power Plants location choice fromLhasa Dunhuang and Delingha in China the optical

14 International Journal of Photoenergy

DunhuangLhasaDelingha

00

02

04

06

08

10

Ann

ual c

olle

ctor

aver

age o

ptic

al effi

cien

cy

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a) Annual collector average optical efficiency

DunhuangLhasaDelingha

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Ann

ual e

nd lo

ss eff

ect

(b) Annual end loss effect

DunhuangLhasaDelingha

00

02

04

06

08

10

Ann

ual r

ow sh

adow

ing

effec

t

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c) Annual row shadowing

DunhuangLhasaDelingha

00

02

04

06

08

10A

nnua

l col

lect

or co

sine e

ffect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d) Annual collector cosine effect

Figure 12 Annual values of cosine effect shadowing effect end loss effect and optical efficiency

efficiency of PTCs in Lhasa is higher than the other 2regions

4 Conclusions

In the paper the optical efficiency calculation method ofparabolic trough solar collector was used to analyze andstudy the performance of parabolic trough solar collectorat Dunhuang Delingha and Lhasa in China The first dayof every month during a year was chosen as a time ofcalculation mainly cosine effect shadowing effect end losseffect and optical efficiency were calculated

From PTCs in these three areas in China simulationresults some overall conclusions could be derived as follows

(1) In this paper a mathematical model of parabolictrough solar concentrator is established which isvalidated by comparing the test results in SEGS VIand performance simulation results can correctlyreflect the operating characteristics of PTCs

(2) The optical efficiency of PTC changes from 04 to08 in a whole year The efficiency first decreased andthen increased with the turning point of the change atnoon The highest operating efficiency in these threeareas is in JuneThe lowest operating collector opticalefficiency is in December

(3) The shadowing losses are introduced by collectorshading during approximately the first and last 90

International Journal of Photoenergy 15

minutes of operation each day The end loss factorranged from 0985 to 1

(4) The optical efficiency of PTCs is mainly influencedby the incident angle of the sun shadowing effectand end loss effect are weak in the effect of opticalefficiency

(5) The annual optical efficiency of the parabolic troughsolar collector running in Lhasa is the highest in thesethree areas

The analytical method to performance simulation for theoptical efficiency of solar concentrator can be applied to otherconcentrated solar systems We are developing the programfor performance simulation for solar tower system in China

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

This study was simultaneously supported by the Key Labo-ratory Open Fund Project of Jiangsu Provincial Key Labo-ratory of Solar Energy Science and Technology (Grant noJPKLSST201504) and the Natural Science Foundation of theJiangsu Higher Education Institutions of China (Grant no14KJD470003)

References

[1] O Behar A Khellaf and K Mohammedi ldquoA review of studieson central receiver solar thermal power plantsrdquo Renewable andSustainable Energy Reviews vol 23 pp 12ndash39 2013

[2] A H Slocum D S Codd J Buongiorno et al ldquoConcentratedsolar power on demandrdquo Solar Energy vol 85 no 7 pp 1519ndash1529 2011

[3] H L Zhang J Baeyens J Degreve and G Caceres ldquoCon-centrated solar power plants review and design methodologyrdquoRenewable and Sustainable Energy Reviews vol 22 pp 466ndash4812013

[4] Office of the State Council of China ldquoStrategic action planfor energy development (2014ndash2020)rdquo 2014 (Chinese)httpwwwgovcnzhengcecontent2014-1119content 9222htm

[5] Dunhuang Energy Bureau Environmental Assessment Docu-ment for Dunhuang 10 MW of Solar Thermal Power Gen-eration Projects Dunhuang Energy Bureau 2015 (Chinese)httpwwwdunhuanggovcnReadNewsaspNewsID=16475

[6] A A Hachicha I Rodrıguez R Capdevila and A Oliva ldquoHeattransfer analysis and numerical simulation of a parabolic troughsolar collectorrdquoApplied Energy vol 111 no 11 pp 581ndash592 2013

[7] S A Kalogirou ldquoA detailed thermalmodel of a parabolic troughcollector receiverrdquo Energy vol 48 no 1 pp 298ndash306 2012

[8] H Muller-Steinhagen and F Trieb ldquolsquoConcentrating solarpowerrsquo A review of the technologyrdquo Quarterly of the RoyalAcademy of Engineering no 18 pp 43ndash50 2004

[9] A Fernandez-Garcıa E Zarza L Valenzuela and M PerezldquoParabolic-trough solar collectors and their applicationsrdquo

Renewable and Sustainable Energy Reviews vol 14 no 7 pp1695ndash1721 2010

[10] W Jinping W Jun Z Yaoming and B Xiaolong ldquoAnalysis ofheat transfer characteristics for parabolic trough solar collectorrdquoTransactions of the Chinese Society of Agricultural Engineeringvol 31 no 7 pp 185ndash192 2015 (Chinese)

[11] K M Knight S A Klein and J A Duffie ldquoA methodology forthe synthesis of hourly weather datardquo Solar Energy vol 46 no2 pp 109ndash120 1991

[12] M Petrakis H D Kambezidis S Lykoudis et al ldquoGeneration ofa lsquotypical meteorological yearrsquo for Nicosia Cyprusrdquo RenewableEnergy vol 13 no 3 pp 381ndash388 1998

[13] G Florides S Kalogirou K Theophilou et al ldquoAnalysis ofthe typical meteorological year (TMY) of Cyprus and houseload simulationrdquo in Proceedings of the 8th International IBPSAConference Eindhoven The Netherlands 2003

[14] J Garcıa-Barberena P GarciaM Sanchez et al ldquoAnalysis of theinfluence of operational strategies in plant performance usingSimulCET simulation software for parabolic trough powerplantsrdquo Solar Energy vol 86 no 1 pp 53ndash63 2012

[15] J Bonilla L J Yebra S Dormido and E Zarza ldquoParabolic-trough solar thermal power plant simulation scheme multi-objective genetic algorithm calibration and validationrdquo SolarEnergy vol 86 no 1 pp 531ndash540 2012

[16] P H Wagner and M Wittmann ldquoInfluence of different oper-ation strategies on transient solar thermal power plant simu-lation models with molten salt as heat transfer fluidrdquo EnergyProcedia vol 49 pp 1652ndash1663 2012

[17] W Huang P Hu and Z Chen ldquoPerformance simulation of aparabolic trough solar collectorrdquo Solar Energy vol 86 no 2 pp746ndash755 2012

[18] X Zhang W Xu T He et al ldquoSolar thermal system evaluationinChinardquo International Journal of Photoenergy vol 2015 ArticleID 163808 12 pages 2015

[19] W B Stine and R W Harrigan Solar Energy Fundamentalsand Design With Computer Applications John Wiley amp SonsHoboken NJ USA 1985

[20] W Jinping W Jun F Wei W Dengwen and Z YaomingldquoDevelopment and application of sun-tracking control systemfor parabolic trough solar collectorrdquo Transactions of the ChineseSociety of Agricultural Engineering vol 31 no 2 pp 45ndash52 2015

[21] R Dhanabal V Bharathi R Ranjitha A Ponni S Deepthi andP Mageshkannan ldquoComparison of efficiencies of solar trackersystems with static panel single-axis tracking system and dual-axis tracking system with fixed mountrdquo International Journal ofEngineering amp Technology vol 5 no 2 pp 1925ndash1933 2013

[22] CK Pandey andAKKatiyar ldquoAnote ondiffuse solar radiationon a tilted surfacerdquo Energy vol 34 no 11 pp 1764ndash1769 2009

[23] G Morin J Dersch W Platzer M Eck and A HaberleldquoComparison of linear Fresnel and parabolic trough collectorpower plantsrdquo Solar Energy vol 86 no 1 pp 1ndash12 2012

[24] K J Riffelmann ldquoComparison between PTR70 and UVACefficiency tests thermal loss measurements and Raytracingexperimentsrdquo Status Seminar vol 1 no 7 pp 187ndash197 2005

[25] F Lippke ldquoSimulation of the part load behaviour of a 30MW SEGS plantrdquo Tech Rep SAND95-1293 Sandia NationalLaboratories Albuquerque NM USA 1995

[26] V Dudley G Kolb M Sloan and D Kearney ldquoSEGS LS2solar collector test resultsrdquo Tech Rep SAND94-1884 SandiaNational Laboratories Albuquerque NM USA 1994

16 International Journal of Photoenergy

[27] M J Wagner and P Gilman ldquoTechnical manual for the SAMphysical trough modelrdquo Tech Rep Sandia National Laborato-ries Albuquerque NM USA 2011

[28] A M Patnode Simulation and performance evaluation ofparabolic trough solar power plants [Diss] University ofWisconsin-Madison Madison Wis USA 2006

[29] J Duffie and W Beckman Solar Engineering of Thermal Pro-cesses JohnWileyamp SonsHobokenNJUSA 3rd edition 2006

[30] M Ibanez Plana J Rosell Polo and J I Rosell Urrutia Tec-nologıa Solar Ediciones Mundi-Prensa Madrid Spain 2005

[31] B Bourges ldquoImprovement in solar declination computationrdquoSolar Energy vol 35 no 4 pp 367ndash369 1985

[32] httpwwwnrelgovcspsolarpacesproject detailcfmprojectID=33

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

10 International Journal of Photoenergy

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Jan

end

loss

effec

t

(a)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Feb

end

loss

effec

t

(b)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Mar

end

loss

effec

t

(c)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000Ap

r end

loss

effec

t

(d)

4 6 8 10 12Time of day (h)

14 16 18 20 22 240965

0970

0975

0980

0985

0990

0995

1000

May

end

loss

effec

t

(e)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Jun

end

loss

effec

t

(f)

Figure 10 Continued

International Journal of Photoenergy 11

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000Ju

l end

loss

effec

t

(g)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Aug

end

loss

effec

t

(h)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Sep

end

loss

effec

t

(i)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Oct

end

loss

effec

t

(j)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Nov

end

loss

effec

t

DunhuangLhasaDelingha

(k)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Dec

end

loss

effec

t

DunhuangLhasaDelingha

(l)

Figure 10 End loss factor

Delingha is 461 andDunhuang is 448The annual valuesof shadowing effect and shadowing effect are very large closeto 100The trend of annual cosine effect change is consistentwith the trend of optical efficiency which reveals that theoptical efficiency is mainly influenced by the incident angle

of the sun nevertheless shadowing effect and end loss effectare weak in the effect of optical efficiency

From the analysis above we conclude that the opticalefficiency of parabolic trough solar concentrator collectorsmainly by the impact of the incident angle of the sun

12 International Journal of Photoenergy

00

02

04

06

08

10

Jan

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a)

00

02

04

06

08

10

Feb

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(b)

00

02

04

06

08

10

Mar

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c)

00

02

04

06

08

10Ap

r row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d)

00

02

04

06

08

10

May

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(e)

00

02

04

06

08

10

Jun

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(f)

Figure 11 Continued

International Journal of Photoenergy 13

00

02

04

06

08

10Ju

l row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(g)

00

02

04

06

08

10

Aug

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(h)

00

02

04

06

08

10

Sep

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(i)

00

02

04

06

08

10

Oct

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(j)

00

02

04

06

08

10

Nov

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

DunhuangLhasaDelingha

(k)

00

02

04

06

08

10

Dec

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

DunhuangLhasaDelingha

(l)

Figure 11 Shadowing effect

shadowing effect and end loss effect are almost negligibleThe incident angle of the sun ismainly influenced by differentgeographic locations of parabolic trough solar concentratingcollector So the conclusion has important implications for

the sites selection of parabolic trough solar thermal powerplant

For Parabolic Trough Power Plants location choice fromLhasa Dunhuang and Delingha in China the optical

14 International Journal of Photoenergy

DunhuangLhasaDelingha

00

02

04

06

08

10

Ann

ual c

olle

ctor

aver

age o

ptic

al effi

cien

cy

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a) Annual collector average optical efficiency

DunhuangLhasaDelingha

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Ann

ual e

nd lo

ss eff

ect

(b) Annual end loss effect

DunhuangLhasaDelingha

00

02

04

06

08

10

Ann

ual r

ow sh

adow

ing

effec

t

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c) Annual row shadowing

DunhuangLhasaDelingha

00

02

04

06

08

10A

nnua

l col

lect

or co

sine e

ffect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d) Annual collector cosine effect

Figure 12 Annual values of cosine effect shadowing effect end loss effect and optical efficiency

efficiency of PTCs in Lhasa is higher than the other 2regions

4 Conclusions

In the paper the optical efficiency calculation method ofparabolic trough solar collector was used to analyze andstudy the performance of parabolic trough solar collectorat Dunhuang Delingha and Lhasa in China The first dayof every month during a year was chosen as a time ofcalculation mainly cosine effect shadowing effect end losseffect and optical efficiency were calculated

From PTCs in these three areas in China simulationresults some overall conclusions could be derived as follows

(1) In this paper a mathematical model of parabolictrough solar concentrator is established which isvalidated by comparing the test results in SEGS VIand performance simulation results can correctlyreflect the operating characteristics of PTCs

(2) The optical efficiency of PTC changes from 04 to08 in a whole year The efficiency first decreased andthen increased with the turning point of the change atnoon The highest operating efficiency in these threeareas is in JuneThe lowest operating collector opticalefficiency is in December

(3) The shadowing losses are introduced by collectorshading during approximately the first and last 90

International Journal of Photoenergy 15

minutes of operation each day The end loss factorranged from 0985 to 1

(4) The optical efficiency of PTCs is mainly influencedby the incident angle of the sun shadowing effectand end loss effect are weak in the effect of opticalefficiency

(5) The annual optical efficiency of the parabolic troughsolar collector running in Lhasa is the highest in thesethree areas

The analytical method to performance simulation for theoptical efficiency of solar concentrator can be applied to otherconcentrated solar systems We are developing the programfor performance simulation for solar tower system in China

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

This study was simultaneously supported by the Key Labo-ratory Open Fund Project of Jiangsu Provincial Key Labo-ratory of Solar Energy Science and Technology (Grant noJPKLSST201504) and the Natural Science Foundation of theJiangsu Higher Education Institutions of China (Grant no14KJD470003)

References

[1] O Behar A Khellaf and K Mohammedi ldquoA review of studieson central receiver solar thermal power plantsrdquo Renewable andSustainable Energy Reviews vol 23 pp 12ndash39 2013

[2] A H Slocum D S Codd J Buongiorno et al ldquoConcentratedsolar power on demandrdquo Solar Energy vol 85 no 7 pp 1519ndash1529 2011

[3] H L Zhang J Baeyens J Degreve and G Caceres ldquoCon-centrated solar power plants review and design methodologyrdquoRenewable and Sustainable Energy Reviews vol 22 pp 466ndash4812013

[4] Office of the State Council of China ldquoStrategic action planfor energy development (2014ndash2020)rdquo 2014 (Chinese)httpwwwgovcnzhengcecontent2014-1119content 9222htm

[5] Dunhuang Energy Bureau Environmental Assessment Docu-ment for Dunhuang 10 MW of Solar Thermal Power Gen-eration Projects Dunhuang Energy Bureau 2015 (Chinese)httpwwwdunhuanggovcnReadNewsaspNewsID=16475

[6] A A Hachicha I Rodrıguez R Capdevila and A Oliva ldquoHeattransfer analysis and numerical simulation of a parabolic troughsolar collectorrdquoApplied Energy vol 111 no 11 pp 581ndash592 2013

[7] S A Kalogirou ldquoA detailed thermalmodel of a parabolic troughcollector receiverrdquo Energy vol 48 no 1 pp 298ndash306 2012

[8] H Muller-Steinhagen and F Trieb ldquolsquoConcentrating solarpowerrsquo A review of the technologyrdquo Quarterly of the RoyalAcademy of Engineering no 18 pp 43ndash50 2004

[9] A Fernandez-Garcıa E Zarza L Valenzuela and M PerezldquoParabolic-trough solar collectors and their applicationsrdquo

Renewable and Sustainable Energy Reviews vol 14 no 7 pp1695ndash1721 2010

[10] W Jinping W Jun Z Yaoming and B Xiaolong ldquoAnalysis ofheat transfer characteristics for parabolic trough solar collectorrdquoTransactions of the Chinese Society of Agricultural Engineeringvol 31 no 7 pp 185ndash192 2015 (Chinese)

[11] K M Knight S A Klein and J A Duffie ldquoA methodology forthe synthesis of hourly weather datardquo Solar Energy vol 46 no2 pp 109ndash120 1991

[12] M Petrakis H D Kambezidis S Lykoudis et al ldquoGeneration ofa lsquotypical meteorological yearrsquo for Nicosia Cyprusrdquo RenewableEnergy vol 13 no 3 pp 381ndash388 1998

[13] G Florides S Kalogirou K Theophilou et al ldquoAnalysis ofthe typical meteorological year (TMY) of Cyprus and houseload simulationrdquo in Proceedings of the 8th International IBPSAConference Eindhoven The Netherlands 2003

[14] J Garcıa-Barberena P GarciaM Sanchez et al ldquoAnalysis of theinfluence of operational strategies in plant performance usingSimulCET simulation software for parabolic trough powerplantsrdquo Solar Energy vol 86 no 1 pp 53ndash63 2012

[15] J Bonilla L J Yebra S Dormido and E Zarza ldquoParabolic-trough solar thermal power plant simulation scheme multi-objective genetic algorithm calibration and validationrdquo SolarEnergy vol 86 no 1 pp 531ndash540 2012

[16] P H Wagner and M Wittmann ldquoInfluence of different oper-ation strategies on transient solar thermal power plant simu-lation models with molten salt as heat transfer fluidrdquo EnergyProcedia vol 49 pp 1652ndash1663 2012

[17] W Huang P Hu and Z Chen ldquoPerformance simulation of aparabolic trough solar collectorrdquo Solar Energy vol 86 no 2 pp746ndash755 2012

[18] X Zhang W Xu T He et al ldquoSolar thermal system evaluationinChinardquo International Journal of Photoenergy vol 2015 ArticleID 163808 12 pages 2015

[19] W B Stine and R W Harrigan Solar Energy Fundamentalsand Design With Computer Applications John Wiley amp SonsHoboken NJ USA 1985

[20] W Jinping W Jun F Wei W Dengwen and Z YaomingldquoDevelopment and application of sun-tracking control systemfor parabolic trough solar collectorrdquo Transactions of the ChineseSociety of Agricultural Engineering vol 31 no 2 pp 45ndash52 2015

[21] R Dhanabal V Bharathi R Ranjitha A Ponni S Deepthi andP Mageshkannan ldquoComparison of efficiencies of solar trackersystems with static panel single-axis tracking system and dual-axis tracking system with fixed mountrdquo International Journal ofEngineering amp Technology vol 5 no 2 pp 1925ndash1933 2013

[22] CK Pandey andAKKatiyar ldquoAnote ondiffuse solar radiationon a tilted surfacerdquo Energy vol 34 no 11 pp 1764ndash1769 2009

[23] G Morin J Dersch W Platzer M Eck and A HaberleldquoComparison of linear Fresnel and parabolic trough collectorpower plantsrdquo Solar Energy vol 86 no 1 pp 1ndash12 2012

[24] K J Riffelmann ldquoComparison between PTR70 and UVACefficiency tests thermal loss measurements and Raytracingexperimentsrdquo Status Seminar vol 1 no 7 pp 187ndash197 2005

[25] F Lippke ldquoSimulation of the part load behaviour of a 30MW SEGS plantrdquo Tech Rep SAND95-1293 Sandia NationalLaboratories Albuquerque NM USA 1995

[26] V Dudley G Kolb M Sloan and D Kearney ldquoSEGS LS2solar collector test resultsrdquo Tech Rep SAND94-1884 SandiaNational Laboratories Albuquerque NM USA 1994

16 International Journal of Photoenergy

[27] M J Wagner and P Gilman ldquoTechnical manual for the SAMphysical trough modelrdquo Tech Rep Sandia National Laborato-ries Albuquerque NM USA 2011

[28] A M Patnode Simulation and performance evaluation ofparabolic trough solar power plants [Diss] University ofWisconsin-Madison Madison Wis USA 2006

[29] J Duffie and W Beckman Solar Engineering of Thermal Pro-cesses JohnWileyamp SonsHobokenNJUSA 3rd edition 2006

[30] M Ibanez Plana J Rosell Polo and J I Rosell Urrutia Tec-nologıa Solar Ediciones Mundi-Prensa Madrid Spain 2005

[31] B Bourges ldquoImprovement in solar declination computationrdquoSolar Energy vol 35 no 4 pp 367ndash369 1985

[32] httpwwwnrelgovcspsolarpacesproject detailcfmprojectID=33

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

International Journal of Photoenergy 11

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000Ju

l end

loss

effec

t

(g)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Aug

end

loss

effec

t

(h)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Sep

end

loss

effec

t

(i)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Oct

end

loss

effec

t

(j)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Nov

end

loss

effec

t

DunhuangLhasaDelingha

(k)

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Dec

end

loss

effec

t

DunhuangLhasaDelingha

(l)

Figure 10 End loss factor

Delingha is 461 andDunhuang is 448The annual valuesof shadowing effect and shadowing effect are very large closeto 100The trend of annual cosine effect change is consistentwith the trend of optical efficiency which reveals that theoptical efficiency is mainly influenced by the incident angle

of the sun nevertheless shadowing effect and end loss effectare weak in the effect of optical efficiency

From the analysis above we conclude that the opticalefficiency of parabolic trough solar concentrator collectorsmainly by the impact of the incident angle of the sun

12 International Journal of Photoenergy

00

02

04

06

08

10

Jan

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a)

00

02

04

06

08

10

Feb

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(b)

00

02

04

06

08

10

Mar

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c)

00

02

04

06

08

10Ap

r row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d)

00

02

04

06

08

10

May

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(e)

00

02

04

06

08

10

Jun

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(f)

Figure 11 Continued

International Journal of Photoenergy 13

00

02

04

06

08

10Ju

l row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(g)

00

02

04

06

08

10

Aug

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(h)

00

02

04

06

08

10

Sep

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(i)

00

02

04

06

08

10

Oct

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(j)

00

02

04

06

08

10

Nov

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

DunhuangLhasaDelingha

(k)

00

02

04

06

08

10

Dec

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

DunhuangLhasaDelingha

(l)

Figure 11 Shadowing effect

shadowing effect and end loss effect are almost negligibleThe incident angle of the sun ismainly influenced by differentgeographic locations of parabolic trough solar concentratingcollector So the conclusion has important implications for

the sites selection of parabolic trough solar thermal powerplant

For Parabolic Trough Power Plants location choice fromLhasa Dunhuang and Delingha in China the optical

14 International Journal of Photoenergy

DunhuangLhasaDelingha

00

02

04

06

08

10

Ann

ual c

olle

ctor

aver

age o

ptic

al effi

cien

cy

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a) Annual collector average optical efficiency

DunhuangLhasaDelingha

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Ann

ual e

nd lo

ss eff

ect

(b) Annual end loss effect

DunhuangLhasaDelingha

00

02

04

06

08

10

Ann

ual r

ow sh

adow

ing

effec

t

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c) Annual row shadowing

DunhuangLhasaDelingha

00

02

04

06

08

10A

nnua

l col

lect

or co

sine e

ffect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d) Annual collector cosine effect

Figure 12 Annual values of cosine effect shadowing effect end loss effect and optical efficiency

efficiency of PTCs in Lhasa is higher than the other 2regions

4 Conclusions

In the paper the optical efficiency calculation method ofparabolic trough solar collector was used to analyze andstudy the performance of parabolic trough solar collectorat Dunhuang Delingha and Lhasa in China The first dayof every month during a year was chosen as a time ofcalculation mainly cosine effect shadowing effect end losseffect and optical efficiency were calculated

From PTCs in these three areas in China simulationresults some overall conclusions could be derived as follows

(1) In this paper a mathematical model of parabolictrough solar concentrator is established which isvalidated by comparing the test results in SEGS VIand performance simulation results can correctlyreflect the operating characteristics of PTCs

(2) The optical efficiency of PTC changes from 04 to08 in a whole year The efficiency first decreased andthen increased with the turning point of the change atnoon The highest operating efficiency in these threeareas is in JuneThe lowest operating collector opticalefficiency is in December

(3) The shadowing losses are introduced by collectorshading during approximately the first and last 90

International Journal of Photoenergy 15

minutes of operation each day The end loss factorranged from 0985 to 1

(4) The optical efficiency of PTCs is mainly influencedby the incident angle of the sun shadowing effectand end loss effect are weak in the effect of opticalefficiency

(5) The annual optical efficiency of the parabolic troughsolar collector running in Lhasa is the highest in thesethree areas

The analytical method to performance simulation for theoptical efficiency of solar concentrator can be applied to otherconcentrated solar systems We are developing the programfor performance simulation for solar tower system in China

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

This study was simultaneously supported by the Key Labo-ratory Open Fund Project of Jiangsu Provincial Key Labo-ratory of Solar Energy Science and Technology (Grant noJPKLSST201504) and the Natural Science Foundation of theJiangsu Higher Education Institutions of China (Grant no14KJD470003)

References

[1] O Behar A Khellaf and K Mohammedi ldquoA review of studieson central receiver solar thermal power plantsrdquo Renewable andSustainable Energy Reviews vol 23 pp 12ndash39 2013

[2] A H Slocum D S Codd J Buongiorno et al ldquoConcentratedsolar power on demandrdquo Solar Energy vol 85 no 7 pp 1519ndash1529 2011

[3] H L Zhang J Baeyens J Degreve and G Caceres ldquoCon-centrated solar power plants review and design methodologyrdquoRenewable and Sustainable Energy Reviews vol 22 pp 466ndash4812013

[4] Office of the State Council of China ldquoStrategic action planfor energy development (2014ndash2020)rdquo 2014 (Chinese)httpwwwgovcnzhengcecontent2014-1119content 9222htm

[5] Dunhuang Energy Bureau Environmental Assessment Docu-ment for Dunhuang 10 MW of Solar Thermal Power Gen-eration Projects Dunhuang Energy Bureau 2015 (Chinese)httpwwwdunhuanggovcnReadNewsaspNewsID=16475

[6] A A Hachicha I Rodrıguez R Capdevila and A Oliva ldquoHeattransfer analysis and numerical simulation of a parabolic troughsolar collectorrdquoApplied Energy vol 111 no 11 pp 581ndash592 2013

[7] S A Kalogirou ldquoA detailed thermalmodel of a parabolic troughcollector receiverrdquo Energy vol 48 no 1 pp 298ndash306 2012

[8] H Muller-Steinhagen and F Trieb ldquolsquoConcentrating solarpowerrsquo A review of the technologyrdquo Quarterly of the RoyalAcademy of Engineering no 18 pp 43ndash50 2004

[9] A Fernandez-Garcıa E Zarza L Valenzuela and M PerezldquoParabolic-trough solar collectors and their applicationsrdquo

Renewable and Sustainable Energy Reviews vol 14 no 7 pp1695ndash1721 2010

[10] W Jinping W Jun Z Yaoming and B Xiaolong ldquoAnalysis ofheat transfer characteristics for parabolic trough solar collectorrdquoTransactions of the Chinese Society of Agricultural Engineeringvol 31 no 7 pp 185ndash192 2015 (Chinese)

[11] K M Knight S A Klein and J A Duffie ldquoA methodology forthe synthesis of hourly weather datardquo Solar Energy vol 46 no2 pp 109ndash120 1991

[12] M Petrakis H D Kambezidis S Lykoudis et al ldquoGeneration ofa lsquotypical meteorological yearrsquo for Nicosia Cyprusrdquo RenewableEnergy vol 13 no 3 pp 381ndash388 1998

[13] G Florides S Kalogirou K Theophilou et al ldquoAnalysis ofthe typical meteorological year (TMY) of Cyprus and houseload simulationrdquo in Proceedings of the 8th International IBPSAConference Eindhoven The Netherlands 2003

[14] J Garcıa-Barberena P GarciaM Sanchez et al ldquoAnalysis of theinfluence of operational strategies in plant performance usingSimulCET simulation software for parabolic trough powerplantsrdquo Solar Energy vol 86 no 1 pp 53ndash63 2012

[15] J Bonilla L J Yebra S Dormido and E Zarza ldquoParabolic-trough solar thermal power plant simulation scheme multi-objective genetic algorithm calibration and validationrdquo SolarEnergy vol 86 no 1 pp 531ndash540 2012

[16] P H Wagner and M Wittmann ldquoInfluence of different oper-ation strategies on transient solar thermal power plant simu-lation models with molten salt as heat transfer fluidrdquo EnergyProcedia vol 49 pp 1652ndash1663 2012

[17] W Huang P Hu and Z Chen ldquoPerformance simulation of aparabolic trough solar collectorrdquo Solar Energy vol 86 no 2 pp746ndash755 2012

[18] X Zhang W Xu T He et al ldquoSolar thermal system evaluationinChinardquo International Journal of Photoenergy vol 2015 ArticleID 163808 12 pages 2015

[19] W B Stine and R W Harrigan Solar Energy Fundamentalsand Design With Computer Applications John Wiley amp SonsHoboken NJ USA 1985

[20] W Jinping W Jun F Wei W Dengwen and Z YaomingldquoDevelopment and application of sun-tracking control systemfor parabolic trough solar collectorrdquo Transactions of the ChineseSociety of Agricultural Engineering vol 31 no 2 pp 45ndash52 2015

[21] R Dhanabal V Bharathi R Ranjitha A Ponni S Deepthi andP Mageshkannan ldquoComparison of efficiencies of solar trackersystems with static panel single-axis tracking system and dual-axis tracking system with fixed mountrdquo International Journal ofEngineering amp Technology vol 5 no 2 pp 1925ndash1933 2013

[22] CK Pandey andAKKatiyar ldquoAnote ondiffuse solar radiationon a tilted surfacerdquo Energy vol 34 no 11 pp 1764ndash1769 2009

[23] G Morin J Dersch W Platzer M Eck and A HaberleldquoComparison of linear Fresnel and parabolic trough collectorpower plantsrdquo Solar Energy vol 86 no 1 pp 1ndash12 2012

[24] K J Riffelmann ldquoComparison between PTR70 and UVACefficiency tests thermal loss measurements and Raytracingexperimentsrdquo Status Seminar vol 1 no 7 pp 187ndash197 2005

[25] F Lippke ldquoSimulation of the part load behaviour of a 30MW SEGS plantrdquo Tech Rep SAND95-1293 Sandia NationalLaboratories Albuquerque NM USA 1995

[26] V Dudley G Kolb M Sloan and D Kearney ldquoSEGS LS2solar collector test resultsrdquo Tech Rep SAND94-1884 SandiaNational Laboratories Albuquerque NM USA 1994

16 International Journal of Photoenergy

[27] M J Wagner and P Gilman ldquoTechnical manual for the SAMphysical trough modelrdquo Tech Rep Sandia National Laborato-ries Albuquerque NM USA 2011

[28] A M Patnode Simulation and performance evaluation ofparabolic trough solar power plants [Diss] University ofWisconsin-Madison Madison Wis USA 2006

[29] J Duffie and W Beckman Solar Engineering of Thermal Pro-cesses JohnWileyamp SonsHobokenNJUSA 3rd edition 2006

[30] M Ibanez Plana J Rosell Polo and J I Rosell Urrutia Tec-nologıa Solar Ediciones Mundi-Prensa Madrid Spain 2005

[31] B Bourges ldquoImprovement in solar declination computationrdquoSolar Energy vol 35 no 4 pp 367ndash369 1985

[32] httpwwwnrelgovcspsolarpacesproject detailcfmprojectID=33

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

12 International Journal of Photoenergy

00

02

04

06

08

10

Jan

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a)

00

02

04

06

08

10

Feb

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(b)

00

02

04

06

08

10

Mar

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c)

00

02

04

06

08

10Ap

r row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d)

00

02

04

06

08

10

May

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(e)

00

02

04

06

08

10

Jun

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(f)

Figure 11 Continued

International Journal of Photoenergy 13

00

02

04

06

08

10Ju

l row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(g)

00

02

04

06

08

10

Aug

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(h)

00

02

04

06

08

10

Sep

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(i)

00

02

04

06

08

10

Oct

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(j)

00

02

04

06

08

10

Nov

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

DunhuangLhasaDelingha

(k)

00

02

04

06

08

10

Dec

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

DunhuangLhasaDelingha

(l)

Figure 11 Shadowing effect

shadowing effect and end loss effect are almost negligibleThe incident angle of the sun ismainly influenced by differentgeographic locations of parabolic trough solar concentratingcollector So the conclusion has important implications for

the sites selection of parabolic trough solar thermal powerplant

For Parabolic Trough Power Plants location choice fromLhasa Dunhuang and Delingha in China the optical

14 International Journal of Photoenergy

DunhuangLhasaDelingha

00

02

04

06

08

10

Ann

ual c

olle

ctor

aver

age o

ptic

al effi

cien

cy

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a) Annual collector average optical efficiency

DunhuangLhasaDelingha

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Ann

ual e

nd lo

ss eff

ect

(b) Annual end loss effect

DunhuangLhasaDelingha

00

02

04

06

08

10

Ann

ual r

ow sh

adow

ing

effec

t

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c) Annual row shadowing

DunhuangLhasaDelingha

00

02

04

06

08

10A

nnua

l col

lect

or co

sine e

ffect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d) Annual collector cosine effect

Figure 12 Annual values of cosine effect shadowing effect end loss effect and optical efficiency

efficiency of PTCs in Lhasa is higher than the other 2regions

4 Conclusions

In the paper the optical efficiency calculation method ofparabolic trough solar collector was used to analyze andstudy the performance of parabolic trough solar collectorat Dunhuang Delingha and Lhasa in China The first dayof every month during a year was chosen as a time ofcalculation mainly cosine effect shadowing effect end losseffect and optical efficiency were calculated

From PTCs in these three areas in China simulationresults some overall conclusions could be derived as follows

(1) In this paper a mathematical model of parabolictrough solar concentrator is established which isvalidated by comparing the test results in SEGS VIand performance simulation results can correctlyreflect the operating characteristics of PTCs

(2) The optical efficiency of PTC changes from 04 to08 in a whole year The efficiency first decreased andthen increased with the turning point of the change atnoon The highest operating efficiency in these threeareas is in JuneThe lowest operating collector opticalefficiency is in December

(3) The shadowing losses are introduced by collectorshading during approximately the first and last 90

International Journal of Photoenergy 15

minutes of operation each day The end loss factorranged from 0985 to 1

(4) The optical efficiency of PTCs is mainly influencedby the incident angle of the sun shadowing effectand end loss effect are weak in the effect of opticalefficiency

(5) The annual optical efficiency of the parabolic troughsolar collector running in Lhasa is the highest in thesethree areas

The analytical method to performance simulation for theoptical efficiency of solar concentrator can be applied to otherconcentrated solar systems We are developing the programfor performance simulation for solar tower system in China

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

This study was simultaneously supported by the Key Labo-ratory Open Fund Project of Jiangsu Provincial Key Labo-ratory of Solar Energy Science and Technology (Grant noJPKLSST201504) and the Natural Science Foundation of theJiangsu Higher Education Institutions of China (Grant no14KJD470003)

References

[1] O Behar A Khellaf and K Mohammedi ldquoA review of studieson central receiver solar thermal power plantsrdquo Renewable andSustainable Energy Reviews vol 23 pp 12ndash39 2013

[2] A H Slocum D S Codd J Buongiorno et al ldquoConcentratedsolar power on demandrdquo Solar Energy vol 85 no 7 pp 1519ndash1529 2011

[3] H L Zhang J Baeyens J Degreve and G Caceres ldquoCon-centrated solar power plants review and design methodologyrdquoRenewable and Sustainable Energy Reviews vol 22 pp 466ndash4812013

[4] Office of the State Council of China ldquoStrategic action planfor energy development (2014ndash2020)rdquo 2014 (Chinese)httpwwwgovcnzhengcecontent2014-1119content 9222htm

[5] Dunhuang Energy Bureau Environmental Assessment Docu-ment for Dunhuang 10 MW of Solar Thermal Power Gen-eration Projects Dunhuang Energy Bureau 2015 (Chinese)httpwwwdunhuanggovcnReadNewsaspNewsID=16475

[6] A A Hachicha I Rodrıguez R Capdevila and A Oliva ldquoHeattransfer analysis and numerical simulation of a parabolic troughsolar collectorrdquoApplied Energy vol 111 no 11 pp 581ndash592 2013

[7] S A Kalogirou ldquoA detailed thermalmodel of a parabolic troughcollector receiverrdquo Energy vol 48 no 1 pp 298ndash306 2012

[8] H Muller-Steinhagen and F Trieb ldquolsquoConcentrating solarpowerrsquo A review of the technologyrdquo Quarterly of the RoyalAcademy of Engineering no 18 pp 43ndash50 2004

[9] A Fernandez-Garcıa E Zarza L Valenzuela and M PerezldquoParabolic-trough solar collectors and their applicationsrdquo

Renewable and Sustainable Energy Reviews vol 14 no 7 pp1695ndash1721 2010

[10] W Jinping W Jun Z Yaoming and B Xiaolong ldquoAnalysis ofheat transfer characteristics for parabolic trough solar collectorrdquoTransactions of the Chinese Society of Agricultural Engineeringvol 31 no 7 pp 185ndash192 2015 (Chinese)

[11] K M Knight S A Klein and J A Duffie ldquoA methodology forthe synthesis of hourly weather datardquo Solar Energy vol 46 no2 pp 109ndash120 1991

[12] M Petrakis H D Kambezidis S Lykoudis et al ldquoGeneration ofa lsquotypical meteorological yearrsquo for Nicosia Cyprusrdquo RenewableEnergy vol 13 no 3 pp 381ndash388 1998

[13] G Florides S Kalogirou K Theophilou et al ldquoAnalysis ofthe typical meteorological year (TMY) of Cyprus and houseload simulationrdquo in Proceedings of the 8th International IBPSAConference Eindhoven The Netherlands 2003

[14] J Garcıa-Barberena P GarciaM Sanchez et al ldquoAnalysis of theinfluence of operational strategies in plant performance usingSimulCET simulation software for parabolic trough powerplantsrdquo Solar Energy vol 86 no 1 pp 53ndash63 2012

[15] J Bonilla L J Yebra S Dormido and E Zarza ldquoParabolic-trough solar thermal power plant simulation scheme multi-objective genetic algorithm calibration and validationrdquo SolarEnergy vol 86 no 1 pp 531ndash540 2012

[16] P H Wagner and M Wittmann ldquoInfluence of different oper-ation strategies on transient solar thermal power plant simu-lation models with molten salt as heat transfer fluidrdquo EnergyProcedia vol 49 pp 1652ndash1663 2012

[17] W Huang P Hu and Z Chen ldquoPerformance simulation of aparabolic trough solar collectorrdquo Solar Energy vol 86 no 2 pp746ndash755 2012

[18] X Zhang W Xu T He et al ldquoSolar thermal system evaluationinChinardquo International Journal of Photoenergy vol 2015 ArticleID 163808 12 pages 2015

[19] W B Stine and R W Harrigan Solar Energy Fundamentalsand Design With Computer Applications John Wiley amp SonsHoboken NJ USA 1985

[20] W Jinping W Jun F Wei W Dengwen and Z YaomingldquoDevelopment and application of sun-tracking control systemfor parabolic trough solar collectorrdquo Transactions of the ChineseSociety of Agricultural Engineering vol 31 no 2 pp 45ndash52 2015

[21] R Dhanabal V Bharathi R Ranjitha A Ponni S Deepthi andP Mageshkannan ldquoComparison of efficiencies of solar trackersystems with static panel single-axis tracking system and dual-axis tracking system with fixed mountrdquo International Journal ofEngineering amp Technology vol 5 no 2 pp 1925ndash1933 2013

[22] CK Pandey andAKKatiyar ldquoAnote ondiffuse solar radiationon a tilted surfacerdquo Energy vol 34 no 11 pp 1764ndash1769 2009

[23] G Morin J Dersch W Platzer M Eck and A HaberleldquoComparison of linear Fresnel and parabolic trough collectorpower plantsrdquo Solar Energy vol 86 no 1 pp 1ndash12 2012

[24] K J Riffelmann ldquoComparison between PTR70 and UVACefficiency tests thermal loss measurements and Raytracingexperimentsrdquo Status Seminar vol 1 no 7 pp 187ndash197 2005

[25] F Lippke ldquoSimulation of the part load behaviour of a 30MW SEGS plantrdquo Tech Rep SAND95-1293 Sandia NationalLaboratories Albuquerque NM USA 1995

[26] V Dudley G Kolb M Sloan and D Kearney ldquoSEGS LS2solar collector test resultsrdquo Tech Rep SAND94-1884 SandiaNational Laboratories Albuquerque NM USA 1994

16 International Journal of Photoenergy

[27] M J Wagner and P Gilman ldquoTechnical manual for the SAMphysical trough modelrdquo Tech Rep Sandia National Laborato-ries Albuquerque NM USA 2011

[28] A M Patnode Simulation and performance evaluation ofparabolic trough solar power plants [Diss] University ofWisconsin-Madison Madison Wis USA 2006

[29] J Duffie and W Beckman Solar Engineering of Thermal Pro-cesses JohnWileyamp SonsHobokenNJUSA 3rd edition 2006

[30] M Ibanez Plana J Rosell Polo and J I Rosell Urrutia Tec-nologıa Solar Ediciones Mundi-Prensa Madrid Spain 2005

[31] B Bourges ldquoImprovement in solar declination computationrdquoSolar Energy vol 35 no 4 pp 367ndash369 1985

[32] httpwwwnrelgovcspsolarpacesproject detailcfmprojectID=33

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

International Journal of Photoenergy 13

00

02

04

06

08

10Ju

l row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(g)

00

02

04

06

08

10

Aug

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(h)

00

02

04

06

08

10

Sep

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(i)

00

02

04

06

08

10

Oct

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(j)

00

02

04

06

08

10

Nov

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

DunhuangLhasaDelingha

(k)

00

02

04

06

08

10

Dec

row

shad

owin

g eff

ect

6 8 10 12 14 16 18 20 22 244Time of day (h)

DunhuangLhasaDelingha

(l)

Figure 11 Shadowing effect

shadowing effect and end loss effect are almost negligibleThe incident angle of the sun ismainly influenced by differentgeographic locations of parabolic trough solar concentratingcollector So the conclusion has important implications for

the sites selection of parabolic trough solar thermal powerplant

For Parabolic Trough Power Plants location choice fromLhasa Dunhuang and Delingha in China the optical

14 International Journal of Photoenergy

DunhuangLhasaDelingha

00

02

04

06

08

10

Ann

ual c

olle

ctor

aver

age o

ptic

al effi

cien

cy

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a) Annual collector average optical efficiency

DunhuangLhasaDelingha

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Ann

ual e

nd lo

ss eff

ect

(b) Annual end loss effect

DunhuangLhasaDelingha

00

02

04

06

08

10

Ann

ual r

ow sh

adow

ing

effec

t

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c) Annual row shadowing

DunhuangLhasaDelingha

00

02

04

06

08

10A

nnua

l col

lect

or co

sine e

ffect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d) Annual collector cosine effect

Figure 12 Annual values of cosine effect shadowing effect end loss effect and optical efficiency

efficiency of PTCs in Lhasa is higher than the other 2regions

4 Conclusions

In the paper the optical efficiency calculation method ofparabolic trough solar collector was used to analyze andstudy the performance of parabolic trough solar collectorat Dunhuang Delingha and Lhasa in China The first dayof every month during a year was chosen as a time ofcalculation mainly cosine effect shadowing effect end losseffect and optical efficiency were calculated

From PTCs in these three areas in China simulationresults some overall conclusions could be derived as follows

(1) In this paper a mathematical model of parabolictrough solar concentrator is established which isvalidated by comparing the test results in SEGS VIand performance simulation results can correctlyreflect the operating characteristics of PTCs

(2) The optical efficiency of PTC changes from 04 to08 in a whole year The efficiency first decreased andthen increased with the turning point of the change atnoon The highest operating efficiency in these threeareas is in JuneThe lowest operating collector opticalefficiency is in December

(3) The shadowing losses are introduced by collectorshading during approximately the first and last 90

International Journal of Photoenergy 15

minutes of operation each day The end loss factorranged from 0985 to 1

(4) The optical efficiency of PTCs is mainly influencedby the incident angle of the sun shadowing effectand end loss effect are weak in the effect of opticalefficiency

(5) The annual optical efficiency of the parabolic troughsolar collector running in Lhasa is the highest in thesethree areas

The analytical method to performance simulation for theoptical efficiency of solar concentrator can be applied to otherconcentrated solar systems We are developing the programfor performance simulation for solar tower system in China

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

This study was simultaneously supported by the Key Labo-ratory Open Fund Project of Jiangsu Provincial Key Labo-ratory of Solar Energy Science and Technology (Grant noJPKLSST201504) and the Natural Science Foundation of theJiangsu Higher Education Institutions of China (Grant no14KJD470003)

References

[1] O Behar A Khellaf and K Mohammedi ldquoA review of studieson central receiver solar thermal power plantsrdquo Renewable andSustainable Energy Reviews vol 23 pp 12ndash39 2013

[2] A H Slocum D S Codd J Buongiorno et al ldquoConcentratedsolar power on demandrdquo Solar Energy vol 85 no 7 pp 1519ndash1529 2011

[3] H L Zhang J Baeyens J Degreve and G Caceres ldquoCon-centrated solar power plants review and design methodologyrdquoRenewable and Sustainable Energy Reviews vol 22 pp 466ndash4812013

[4] Office of the State Council of China ldquoStrategic action planfor energy development (2014ndash2020)rdquo 2014 (Chinese)httpwwwgovcnzhengcecontent2014-1119content 9222htm

[5] Dunhuang Energy Bureau Environmental Assessment Docu-ment for Dunhuang 10 MW of Solar Thermal Power Gen-eration Projects Dunhuang Energy Bureau 2015 (Chinese)httpwwwdunhuanggovcnReadNewsaspNewsID=16475

[6] A A Hachicha I Rodrıguez R Capdevila and A Oliva ldquoHeattransfer analysis and numerical simulation of a parabolic troughsolar collectorrdquoApplied Energy vol 111 no 11 pp 581ndash592 2013

[7] S A Kalogirou ldquoA detailed thermalmodel of a parabolic troughcollector receiverrdquo Energy vol 48 no 1 pp 298ndash306 2012

[8] H Muller-Steinhagen and F Trieb ldquolsquoConcentrating solarpowerrsquo A review of the technologyrdquo Quarterly of the RoyalAcademy of Engineering no 18 pp 43ndash50 2004

[9] A Fernandez-Garcıa E Zarza L Valenzuela and M PerezldquoParabolic-trough solar collectors and their applicationsrdquo

Renewable and Sustainable Energy Reviews vol 14 no 7 pp1695ndash1721 2010

[10] W Jinping W Jun Z Yaoming and B Xiaolong ldquoAnalysis ofheat transfer characteristics for parabolic trough solar collectorrdquoTransactions of the Chinese Society of Agricultural Engineeringvol 31 no 7 pp 185ndash192 2015 (Chinese)

[11] K M Knight S A Klein and J A Duffie ldquoA methodology forthe synthesis of hourly weather datardquo Solar Energy vol 46 no2 pp 109ndash120 1991

[12] M Petrakis H D Kambezidis S Lykoudis et al ldquoGeneration ofa lsquotypical meteorological yearrsquo for Nicosia Cyprusrdquo RenewableEnergy vol 13 no 3 pp 381ndash388 1998

[13] G Florides S Kalogirou K Theophilou et al ldquoAnalysis ofthe typical meteorological year (TMY) of Cyprus and houseload simulationrdquo in Proceedings of the 8th International IBPSAConference Eindhoven The Netherlands 2003

[14] J Garcıa-Barberena P GarciaM Sanchez et al ldquoAnalysis of theinfluence of operational strategies in plant performance usingSimulCET simulation software for parabolic trough powerplantsrdquo Solar Energy vol 86 no 1 pp 53ndash63 2012

[15] J Bonilla L J Yebra S Dormido and E Zarza ldquoParabolic-trough solar thermal power plant simulation scheme multi-objective genetic algorithm calibration and validationrdquo SolarEnergy vol 86 no 1 pp 531ndash540 2012

[16] P H Wagner and M Wittmann ldquoInfluence of different oper-ation strategies on transient solar thermal power plant simu-lation models with molten salt as heat transfer fluidrdquo EnergyProcedia vol 49 pp 1652ndash1663 2012

[17] W Huang P Hu and Z Chen ldquoPerformance simulation of aparabolic trough solar collectorrdquo Solar Energy vol 86 no 2 pp746ndash755 2012

[18] X Zhang W Xu T He et al ldquoSolar thermal system evaluationinChinardquo International Journal of Photoenergy vol 2015 ArticleID 163808 12 pages 2015

[19] W B Stine and R W Harrigan Solar Energy Fundamentalsand Design With Computer Applications John Wiley amp SonsHoboken NJ USA 1985

[20] W Jinping W Jun F Wei W Dengwen and Z YaomingldquoDevelopment and application of sun-tracking control systemfor parabolic trough solar collectorrdquo Transactions of the ChineseSociety of Agricultural Engineering vol 31 no 2 pp 45ndash52 2015

[21] R Dhanabal V Bharathi R Ranjitha A Ponni S Deepthi andP Mageshkannan ldquoComparison of efficiencies of solar trackersystems with static panel single-axis tracking system and dual-axis tracking system with fixed mountrdquo International Journal ofEngineering amp Technology vol 5 no 2 pp 1925ndash1933 2013

[22] CK Pandey andAKKatiyar ldquoAnote ondiffuse solar radiationon a tilted surfacerdquo Energy vol 34 no 11 pp 1764ndash1769 2009

[23] G Morin J Dersch W Platzer M Eck and A HaberleldquoComparison of linear Fresnel and parabolic trough collectorpower plantsrdquo Solar Energy vol 86 no 1 pp 1ndash12 2012

[24] K J Riffelmann ldquoComparison between PTR70 and UVACefficiency tests thermal loss measurements and Raytracingexperimentsrdquo Status Seminar vol 1 no 7 pp 187ndash197 2005

[25] F Lippke ldquoSimulation of the part load behaviour of a 30MW SEGS plantrdquo Tech Rep SAND95-1293 Sandia NationalLaboratories Albuquerque NM USA 1995

[26] V Dudley G Kolb M Sloan and D Kearney ldquoSEGS LS2solar collector test resultsrdquo Tech Rep SAND94-1884 SandiaNational Laboratories Albuquerque NM USA 1994

16 International Journal of Photoenergy

[27] M J Wagner and P Gilman ldquoTechnical manual for the SAMphysical trough modelrdquo Tech Rep Sandia National Laborato-ries Albuquerque NM USA 2011

[28] A M Patnode Simulation and performance evaluation ofparabolic trough solar power plants [Diss] University ofWisconsin-Madison Madison Wis USA 2006

[29] J Duffie and W Beckman Solar Engineering of Thermal Pro-cesses JohnWileyamp SonsHobokenNJUSA 3rd edition 2006

[30] M Ibanez Plana J Rosell Polo and J I Rosell Urrutia Tec-nologıa Solar Ediciones Mundi-Prensa Madrid Spain 2005

[31] B Bourges ldquoImprovement in solar declination computationrdquoSolar Energy vol 35 no 4 pp 367ndash369 1985

[32] httpwwwnrelgovcspsolarpacesproject detailcfmprojectID=33

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

14 International Journal of Photoenergy

DunhuangLhasaDelingha

00

02

04

06

08

10

Ann

ual c

olle

ctor

aver

age o

ptic

al effi

cien

cy

6 8 10 12 14 16 18 20 22 244Time of day (h)

(a) Annual collector average optical efficiency

DunhuangLhasaDelingha

6 8 10 12 14 16 18 20 22 244Time of day (h)

0965

0970

0975

0980

0985

0990

0995

1000

Ann

ual e

nd lo

ss eff

ect

(b) Annual end loss effect

DunhuangLhasaDelingha

00

02

04

06

08

10

Ann

ual r

ow sh

adow

ing

effec

t

6 8 10 12 14 16 18 20 22 244Time of day (h)

(c) Annual row shadowing

DunhuangLhasaDelingha

00

02

04

06

08

10A

nnua

l col

lect

or co

sine e

ffect

6 8 10 12 14 16 18 20 22 244Time of day (h)

(d) Annual collector cosine effect

Figure 12 Annual values of cosine effect shadowing effect end loss effect and optical efficiency

efficiency of PTCs in Lhasa is higher than the other 2regions

4 Conclusions

In the paper the optical efficiency calculation method ofparabolic trough solar collector was used to analyze andstudy the performance of parabolic trough solar collectorat Dunhuang Delingha and Lhasa in China The first dayof every month during a year was chosen as a time ofcalculation mainly cosine effect shadowing effect end losseffect and optical efficiency were calculated

From PTCs in these three areas in China simulationresults some overall conclusions could be derived as follows

(1) In this paper a mathematical model of parabolictrough solar concentrator is established which isvalidated by comparing the test results in SEGS VIand performance simulation results can correctlyreflect the operating characteristics of PTCs

(2) The optical efficiency of PTC changes from 04 to08 in a whole year The efficiency first decreased andthen increased with the turning point of the change atnoon The highest operating efficiency in these threeareas is in JuneThe lowest operating collector opticalefficiency is in December

(3) The shadowing losses are introduced by collectorshading during approximately the first and last 90

International Journal of Photoenergy 15

minutes of operation each day The end loss factorranged from 0985 to 1

(4) The optical efficiency of PTCs is mainly influencedby the incident angle of the sun shadowing effectand end loss effect are weak in the effect of opticalefficiency

(5) The annual optical efficiency of the parabolic troughsolar collector running in Lhasa is the highest in thesethree areas

The analytical method to performance simulation for theoptical efficiency of solar concentrator can be applied to otherconcentrated solar systems We are developing the programfor performance simulation for solar tower system in China

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

This study was simultaneously supported by the Key Labo-ratory Open Fund Project of Jiangsu Provincial Key Labo-ratory of Solar Energy Science and Technology (Grant noJPKLSST201504) and the Natural Science Foundation of theJiangsu Higher Education Institutions of China (Grant no14KJD470003)

References

[1] O Behar A Khellaf and K Mohammedi ldquoA review of studieson central receiver solar thermal power plantsrdquo Renewable andSustainable Energy Reviews vol 23 pp 12ndash39 2013

[2] A H Slocum D S Codd J Buongiorno et al ldquoConcentratedsolar power on demandrdquo Solar Energy vol 85 no 7 pp 1519ndash1529 2011

[3] H L Zhang J Baeyens J Degreve and G Caceres ldquoCon-centrated solar power plants review and design methodologyrdquoRenewable and Sustainable Energy Reviews vol 22 pp 466ndash4812013

[4] Office of the State Council of China ldquoStrategic action planfor energy development (2014ndash2020)rdquo 2014 (Chinese)httpwwwgovcnzhengcecontent2014-1119content 9222htm

[5] Dunhuang Energy Bureau Environmental Assessment Docu-ment for Dunhuang 10 MW of Solar Thermal Power Gen-eration Projects Dunhuang Energy Bureau 2015 (Chinese)httpwwwdunhuanggovcnReadNewsaspNewsID=16475

[6] A A Hachicha I Rodrıguez R Capdevila and A Oliva ldquoHeattransfer analysis and numerical simulation of a parabolic troughsolar collectorrdquoApplied Energy vol 111 no 11 pp 581ndash592 2013

[7] S A Kalogirou ldquoA detailed thermalmodel of a parabolic troughcollector receiverrdquo Energy vol 48 no 1 pp 298ndash306 2012

[8] H Muller-Steinhagen and F Trieb ldquolsquoConcentrating solarpowerrsquo A review of the technologyrdquo Quarterly of the RoyalAcademy of Engineering no 18 pp 43ndash50 2004

[9] A Fernandez-Garcıa E Zarza L Valenzuela and M PerezldquoParabolic-trough solar collectors and their applicationsrdquo

Renewable and Sustainable Energy Reviews vol 14 no 7 pp1695ndash1721 2010

[10] W Jinping W Jun Z Yaoming and B Xiaolong ldquoAnalysis ofheat transfer characteristics for parabolic trough solar collectorrdquoTransactions of the Chinese Society of Agricultural Engineeringvol 31 no 7 pp 185ndash192 2015 (Chinese)

[11] K M Knight S A Klein and J A Duffie ldquoA methodology forthe synthesis of hourly weather datardquo Solar Energy vol 46 no2 pp 109ndash120 1991

[12] M Petrakis H D Kambezidis S Lykoudis et al ldquoGeneration ofa lsquotypical meteorological yearrsquo for Nicosia Cyprusrdquo RenewableEnergy vol 13 no 3 pp 381ndash388 1998

[13] G Florides S Kalogirou K Theophilou et al ldquoAnalysis ofthe typical meteorological year (TMY) of Cyprus and houseload simulationrdquo in Proceedings of the 8th International IBPSAConference Eindhoven The Netherlands 2003

[14] J Garcıa-Barberena P GarciaM Sanchez et al ldquoAnalysis of theinfluence of operational strategies in plant performance usingSimulCET simulation software for parabolic trough powerplantsrdquo Solar Energy vol 86 no 1 pp 53ndash63 2012

[15] J Bonilla L J Yebra S Dormido and E Zarza ldquoParabolic-trough solar thermal power plant simulation scheme multi-objective genetic algorithm calibration and validationrdquo SolarEnergy vol 86 no 1 pp 531ndash540 2012

[16] P H Wagner and M Wittmann ldquoInfluence of different oper-ation strategies on transient solar thermal power plant simu-lation models with molten salt as heat transfer fluidrdquo EnergyProcedia vol 49 pp 1652ndash1663 2012

[17] W Huang P Hu and Z Chen ldquoPerformance simulation of aparabolic trough solar collectorrdquo Solar Energy vol 86 no 2 pp746ndash755 2012

[18] X Zhang W Xu T He et al ldquoSolar thermal system evaluationinChinardquo International Journal of Photoenergy vol 2015 ArticleID 163808 12 pages 2015

[19] W B Stine and R W Harrigan Solar Energy Fundamentalsand Design With Computer Applications John Wiley amp SonsHoboken NJ USA 1985

[20] W Jinping W Jun F Wei W Dengwen and Z YaomingldquoDevelopment and application of sun-tracking control systemfor parabolic trough solar collectorrdquo Transactions of the ChineseSociety of Agricultural Engineering vol 31 no 2 pp 45ndash52 2015

[21] R Dhanabal V Bharathi R Ranjitha A Ponni S Deepthi andP Mageshkannan ldquoComparison of efficiencies of solar trackersystems with static panel single-axis tracking system and dual-axis tracking system with fixed mountrdquo International Journal ofEngineering amp Technology vol 5 no 2 pp 1925ndash1933 2013

[22] CK Pandey andAKKatiyar ldquoAnote ondiffuse solar radiationon a tilted surfacerdquo Energy vol 34 no 11 pp 1764ndash1769 2009

[23] G Morin J Dersch W Platzer M Eck and A HaberleldquoComparison of linear Fresnel and parabolic trough collectorpower plantsrdquo Solar Energy vol 86 no 1 pp 1ndash12 2012

[24] K J Riffelmann ldquoComparison between PTR70 and UVACefficiency tests thermal loss measurements and Raytracingexperimentsrdquo Status Seminar vol 1 no 7 pp 187ndash197 2005

[25] F Lippke ldquoSimulation of the part load behaviour of a 30MW SEGS plantrdquo Tech Rep SAND95-1293 Sandia NationalLaboratories Albuquerque NM USA 1995

[26] V Dudley G Kolb M Sloan and D Kearney ldquoSEGS LS2solar collector test resultsrdquo Tech Rep SAND94-1884 SandiaNational Laboratories Albuquerque NM USA 1994

16 International Journal of Photoenergy

[27] M J Wagner and P Gilman ldquoTechnical manual for the SAMphysical trough modelrdquo Tech Rep Sandia National Laborato-ries Albuquerque NM USA 2011

[28] A M Patnode Simulation and performance evaluation ofparabolic trough solar power plants [Diss] University ofWisconsin-Madison Madison Wis USA 2006

[29] J Duffie and W Beckman Solar Engineering of Thermal Pro-cesses JohnWileyamp SonsHobokenNJUSA 3rd edition 2006

[30] M Ibanez Plana J Rosell Polo and J I Rosell Urrutia Tec-nologıa Solar Ediciones Mundi-Prensa Madrid Spain 2005

[31] B Bourges ldquoImprovement in solar declination computationrdquoSolar Energy vol 35 no 4 pp 367ndash369 1985

[32] httpwwwnrelgovcspsolarpacesproject detailcfmprojectID=33

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

International Journal of Photoenergy 15

minutes of operation each day The end loss factorranged from 0985 to 1

(4) The optical efficiency of PTCs is mainly influencedby the incident angle of the sun shadowing effectand end loss effect are weak in the effect of opticalefficiency

(5) The annual optical efficiency of the parabolic troughsolar collector running in Lhasa is the highest in thesethree areas

The analytical method to performance simulation for theoptical efficiency of solar concentrator can be applied to otherconcentrated solar systems We are developing the programfor performance simulation for solar tower system in China

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

This study was simultaneously supported by the Key Labo-ratory Open Fund Project of Jiangsu Provincial Key Labo-ratory of Solar Energy Science and Technology (Grant noJPKLSST201504) and the Natural Science Foundation of theJiangsu Higher Education Institutions of China (Grant no14KJD470003)

References

[1] O Behar A Khellaf and K Mohammedi ldquoA review of studieson central receiver solar thermal power plantsrdquo Renewable andSustainable Energy Reviews vol 23 pp 12ndash39 2013

[2] A H Slocum D S Codd J Buongiorno et al ldquoConcentratedsolar power on demandrdquo Solar Energy vol 85 no 7 pp 1519ndash1529 2011

[3] H L Zhang J Baeyens J Degreve and G Caceres ldquoCon-centrated solar power plants review and design methodologyrdquoRenewable and Sustainable Energy Reviews vol 22 pp 466ndash4812013

[4] Office of the State Council of China ldquoStrategic action planfor energy development (2014ndash2020)rdquo 2014 (Chinese)httpwwwgovcnzhengcecontent2014-1119content 9222htm

[5] Dunhuang Energy Bureau Environmental Assessment Docu-ment for Dunhuang 10 MW of Solar Thermal Power Gen-eration Projects Dunhuang Energy Bureau 2015 (Chinese)httpwwwdunhuanggovcnReadNewsaspNewsID=16475

[6] A A Hachicha I Rodrıguez R Capdevila and A Oliva ldquoHeattransfer analysis and numerical simulation of a parabolic troughsolar collectorrdquoApplied Energy vol 111 no 11 pp 581ndash592 2013

[7] S A Kalogirou ldquoA detailed thermalmodel of a parabolic troughcollector receiverrdquo Energy vol 48 no 1 pp 298ndash306 2012

[8] H Muller-Steinhagen and F Trieb ldquolsquoConcentrating solarpowerrsquo A review of the technologyrdquo Quarterly of the RoyalAcademy of Engineering no 18 pp 43ndash50 2004

[9] A Fernandez-Garcıa E Zarza L Valenzuela and M PerezldquoParabolic-trough solar collectors and their applicationsrdquo

Renewable and Sustainable Energy Reviews vol 14 no 7 pp1695ndash1721 2010

[10] W Jinping W Jun Z Yaoming and B Xiaolong ldquoAnalysis ofheat transfer characteristics for parabolic trough solar collectorrdquoTransactions of the Chinese Society of Agricultural Engineeringvol 31 no 7 pp 185ndash192 2015 (Chinese)

[11] K M Knight S A Klein and J A Duffie ldquoA methodology forthe synthesis of hourly weather datardquo Solar Energy vol 46 no2 pp 109ndash120 1991

[12] M Petrakis H D Kambezidis S Lykoudis et al ldquoGeneration ofa lsquotypical meteorological yearrsquo for Nicosia Cyprusrdquo RenewableEnergy vol 13 no 3 pp 381ndash388 1998

[13] G Florides S Kalogirou K Theophilou et al ldquoAnalysis ofthe typical meteorological year (TMY) of Cyprus and houseload simulationrdquo in Proceedings of the 8th International IBPSAConference Eindhoven The Netherlands 2003

[14] J Garcıa-Barberena P GarciaM Sanchez et al ldquoAnalysis of theinfluence of operational strategies in plant performance usingSimulCET simulation software for parabolic trough powerplantsrdquo Solar Energy vol 86 no 1 pp 53ndash63 2012

[15] J Bonilla L J Yebra S Dormido and E Zarza ldquoParabolic-trough solar thermal power plant simulation scheme multi-objective genetic algorithm calibration and validationrdquo SolarEnergy vol 86 no 1 pp 531ndash540 2012

[16] P H Wagner and M Wittmann ldquoInfluence of different oper-ation strategies on transient solar thermal power plant simu-lation models with molten salt as heat transfer fluidrdquo EnergyProcedia vol 49 pp 1652ndash1663 2012

[17] W Huang P Hu and Z Chen ldquoPerformance simulation of aparabolic trough solar collectorrdquo Solar Energy vol 86 no 2 pp746ndash755 2012

[18] X Zhang W Xu T He et al ldquoSolar thermal system evaluationinChinardquo International Journal of Photoenergy vol 2015 ArticleID 163808 12 pages 2015

[19] W B Stine and R W Harrigan Solar Energy Fundamentalsand Design With Computer Applications John Wiley amp SonsHoboken NJ USA 1985

[20] W Jinping W Jun F Wei W Dengwen and Z YaomingldquoDevelopment and application of sun-tracking control systemfor parabolic trough solar collectorrdquo Transactions of the ChineseSociety of Agricultural Engineering vol 31 no 2 pp 45ndash52 2015

[21] R Dhanabal V Bharathi R Ranjitha A Ponni S Deepthi andP Mageshkannan ldquoComparison of efficiencies of solar trackersystems with static panel single-axis tracking system and dual-axis tracking system with fixed mountrdquo International Journal ofEngineering amp Technology vol 5 no 2 pp 1925ndash1933 2013

[22] CK Pandey andAKKatiyar ldquoAnote ondiffuse solar radiationon a tilted surfacerdquo Energy vol 34 no 11 pp 1764ndash1769 2009

[23] G Morin J Dersch W Platzer M Eck and A HaberleldquoComparison of linear Fresnel and parabolic trough collectorpower plantsrdquo Solar Energy vol 86 no 1 pp 1ndash12 2012

[24] K J Riffelmann ldquoComparison between PTR70 and UVACefficiency tests thermal loss measurements and Raytracingexperimentsrdquo Status Seminar vol 1 no 7 pp 187ndash197 2005

[25] F Lippke ldquoSimulation of the part load behaviour of a 30MW SEGS plantrdquo Tech Rep SAND95-1293 Sandia NationalLaboratories Albuquerque NM USA 1995

[26] V Dudley G Kolb M Sloan and D Kearney ldquoSEGS LS2solar collector test resultsrdquo Tech Rep SAND94-1884 SandiaNational Laboratories Albuquerque NM USA 1994

16 International Journal of Photoenergy

[27] M J Wagner and P Gilman ldquoTechnical manual for the SAMphysical trough modelrdquo Tech Rep Sandia National Laborato-ries Albuquerque NM USA 2011

[28] A M Patnode Simulation and performance evaluation ofparabolic trough solar power plants [Diss] University ofWisconsin-Madison Madison Wis USA 2006

[29] J Duffie and W Beckman Solar Engineering of Thermal Pro-cesses JohnWileyamp SonsHobokenNJUSA 3rd edition 2006

[30] M Ibanez Plana J Rosell Polo and J I Rosell Urrutia Tec-nologıa Solar Ediciones Mundi-Prensa Madrid Spain 2005

[31] B Bourges ldquoImprovement in solar declination computationrdquoSolar Energy vol 35 no 4 pp 367ndash369 1985

[32] httpwwwnrelgovcspsolarpacesproject detailcfmprojectID=33

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

16 International Journal of Photoenergy

[27] M J Wagner and P Gilman ldquoTechnical manual for the SAMphysical trough modelrdquo Tech Rep Sandia National Laborato-ries Albuquerque NM USA 2011

[28] A M Patnode Simulation and performance evaluation ofparabolic trough solar power plants [Diss] University ofWisconsin-Madison Madison Wis USA 2006

[29] J Duffie and W Beckman Solar Engineering of Thermal Pro-cesses JohnWileyamp SonsHobokenNJUSA 3rd edition 2006

[30] M Ibanez Plana J Rosell Polo and J I Rosell Urrutia Tec-nologıa Solar Ediciones Mundi-Prensa Madrid Spain 2005

[31] B Bourges ldquoImprovement in solar declination computationrdquoSolar Energy vol 35 no 4 pp 367ndash369 1985

[32] httpwwwnrelgovcspsolarpacesproject detailcfmprojectID=33

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Carbohydrate Chemistry

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chromatography Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Applied ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Theoretical ChemistryJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Spectroscopy

Analytical ChemistryInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Quantum Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Organic Chemistry International

ElectrochemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CatalystsJournal of