Post on 08-Apr-2016
EXPERIMENTAL MANUAL
MODEL: HE158C
SOLUTION ENGINEERING SDN. BHD.NO.3, JALAN TPK 2/4, TAMAN PERINDUSTRIAN KINRARA,47100 PUCHONG, SELANGOR DARUL EHSAN, MALAYSIA.
TEL: 603-80758000 FAX: 603-80755784E-MAIL: solution@solution.com.my
WEBSITE: www.solution.com.my
236-0510-HE
HEAT EXCHANGERTRAINING
APPARATUS
HEAT EXCHANGERTRAINING
APPARATUS
SOLTEQ® EQUIPMENT FOR ENGINEERING EDUCATION
Table of Contents
Page
List of Figures ....................................................................................................................................... i
List of Tables ....................................................................................................................................... ii
1.0 INTRODUCTION ........................................................................................................................... 1
2.0 GENERAL DESCRIPTION
2.1 Description and Assembly .................................................................................................. 2
2.2 Experimental Capabilities ................................................................................................... 5
2.3 Process Instruments ........................................................................................................... 5
2.4 Overall Dimensions ............................................................................................................. 6
2.5 General Requirements ........................................................................................................ 6
3.0 INSTALLATION AND COMMISSIONING………………………………………………………….. .. 7
3.1 Installation procedures ....... ……………………………………………………………………..7
3.2 Commissioning procedures……………………………………………………………………..7
4.0 SUMMARY OF THEORY
4.1 Shell & Tube Heat Exchanger ............................................................................................ 8
4.2 Spiral Heat Exchanger ...................................................................................................... 17
4.3 Concentric (Double Pipe) Heat Exchanger ....................................................................... 17
4.4 Plate Heat Exchanger ....................................................................................................... 18
5.0 GENERAL OPERATING PROCEDURES .................................................................................. 21
5.1 General Start-up Procedures ............................................................................................ 21
5.2 General Shut-down Procedures ....................................................................................... 21
6.0 EXPERIMENTAL PROCEDURE
6.1 Experiment 1.A: Counter-Current Shell & Tube Heat Exchanger. ................................... 22
6.2 Experiment 1.B: Co-Current Shell & Tube Heat Exchanger............................................. 24
6.3 Experiment 2.A: Counter-Current Spiral Heat Exchanger ................................................ 26
6.4 Experiment 2.B: Co-Current Spiral Heat Exchanger ........................................................ 27
6.5 Experiment 3.A: Counter-Current Concentric Heat Exchanger ........................................ 28
6.6 Experiment 3.B: Co-Current Concentric Heat Exchanger ................................................ 29
6.7 Experiment 4.A: Counter-Current Plate Heat Exchanger ................................................. 30
6.8 Experiment 4.B: Co-Current Plate Heat Exchanger ......................................................... 31
7.0 EQUIPMENT MAINTENANCE ................................................................................................... 32
8.0 SAFETY PRECAUTIONS ........................................................................................................... 32
9.0 REFERENCES ............................................................................................................................ 33
APPENDIX A: EXPERIMENTAL DATA SHEETS
APPENDIX B: CONVERSION FACTORS
APPENDIX C: HEAT EXCHANGER CALCULATION DATA
APPENDIX D: RESULTS SUMMARY
APPENDIX E: SAMPLE CALCULATIONS
APPENDIX F: TEMPERATURE SENSOR CALIBRATION
i
List of Figures Page Figure 1 Schematic Diagram for Heat Exchanger Training Apparatus 4
(Model: HE 158 C)
Figure 2a Temperature profile for a parallel-flow heat exchanger 8 Figure 2b Temperature profile for a counter-flow heat exchanger 8 Figure 2c Temperature profile for a 1:2 heat exchanger 8 Figure 3 Single pass flow plate heat exchanger diagram 20
ii
List of Tables Page Table 1 Valves Arrangement for Flow Selection 5 Table 2 Valves Arrangement for Heat Exchanger Selection 5
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
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1.0 INTRODUCTION
The SOLTEQ® Heat Exchanger Training Apparatus (Model: HE 158C) has been designed to allow students to get familiarized with different kinds of heat exchangers and to collect the necessary experimental data for the calculation of heat losses, heat transfer coefficient, log mean temperature difference, etc. Students will also be able to study the effect of flow rate on the heat transfer rate. The students may apply this knowledge to complex industrial heat exchangers. The unit comes with four different types of heat exchangers and two stainless steel sump tanks for hot and cold water source. The hot tank is fitted with an 11.5 kW immersion type heater that is protected against possible over heating. Each tank has a centrifugal pump capable of delivering the required 10 LPM of water. The pumps are protected from dry-run by electronic level switches installed. All necessary electronic sensors are fitted at suitable locations for measuring the inlet and outlet temperatures of the hot and cold water, and also the flow rates of the hot and cold water streams. Digital indicators are provided on the control panel for students to read the appropriate data. The unit comes with non-corroding type of piping and fittings including all necessary regulating valves. Upon request, an optional data acquisition system can be provided with the unit which includes personal computer, electronic signal conditioning system, stand alone data acquisition modules and Windows based software for data collection and manipulation. The four heat exchangers supplied with the unit are: a) Shell and Tube Heat Exchanger b) Spiral Heat Exchanger c) Concentric (Double Pipe) Heat Exchanger d) Plate Heat Exchanger
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
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2.0 GENERAL DESCRIPTION
2.1 Description and Assembly The SOLTEQ® Heat Exchanger Training Apparatus (Model: HE 158C) consists
of mainly the following items.
a) Shell & Tube Heat Exchanger Tube O.D. (do) : 9.53 mm Tube I.D. (di) : 7.75 mm Tube Length (L) : 500 mm Tube Count (Nt) : 10 (single pass) Tube Pitch (pt) : 18 mm Tube arrangement : Triangle Shell O.D. : 100 mm Shell I.D. (Ds) : 85 mm Baffle Count : 8 Baffle Cut (Bc) : 20 % Baffle Distance (lB) : 50 mm Material of Construction : 316L Stainless Steel/Borosilicate Glass
b) Spiral Heat Exchanger Coil Tubing O.D. : 9.53 mm Coil Tubing I.D. : 7.05 mm Coil Length (L) : 5.00 m Shell O.D. : 100 mm Coil I.D. : 34 mm Coil O.D. : 44 mm Shell I.D. (Ds) : 85 mm Material of Construction : 316L Stainless Steel/Borosilicate
c) Concentric (Double Pipe) Heat Exchanger Tube O.D. (do) : 33.40 mm Tube I.D. (di) : 26.64 mm Length (L) : 500 mm Shell O.D. : 100 mm Shell I.D. (Ds) : 85 mm Material of Construction : 316L Stainless Steel/Borosilicate Glass
d) Plate Heat Exchanger
Nominal Surface : 0.50 m2 Plate Material : 316L stainless steel/copper brazed
No.of plates : 4 Plate length : 309.88 mm Plate channel : 43.18 mm Plate width : 124.46 mm
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
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e) Cold Water Circuit Tank : 50 liter Material : Stainless Steel Circulation Pump : Centrifugal type Operating Flow rate : 10 LPM (dry-run protected by level switch)
f) Hot Water Circuit
Tank : 50 liter Material : Stainless Steel Circulation Pump : Centrifugal type Operating Flow rate : 20 LPM (dry-run protected by level switch) Heating System : 11.5 kW immersion type heater protected by
temperature controller and level switch g) Instrumentations
Measurements of inlet and outlet temperatures for hot water and cold water streams Measurements of flow rates for the hot water and cold water circuits
h) Control Panel To mount all the necessary digital indicators, temperature controller and all switches To house electrical components and wirings To house all the necessary data acquisition modules and signal conditioning unit
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
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Figure 1: Schematic Diagram for Heat Exchanger Training Apparatus (Model: HE 158 C)
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
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2.2 Experimental Capabilities Energy Balance for Heat Exchangers Temperature Profiles in Co-current
2.3 Process Instruments
It is important that the user read and fully understand all the instructions and
precautions stated in the manufacturer's manuals supplied with the unit prior to operating. The following procedures serve as a quick reference for operating the unit.
a) Temperature Controller
The first line displays the liquid temperature in the tank while the second line displays the set value. Adjust the set value as follows:
Press the ENT button, and then press UP or DOWN arrow key continuously until almost near the desired set value.
Press UP or DOWN arrow key one by one until desired set value is reached. Notice that the least digit point is flashing.
Press ENT to register the data. Notice that the least digit point goes off. b) Valve Arrangements
Table 1: Valves Arrangement for Flow Selection OPEN CLOSE LEAVE ALONE Co-Current
V1, V12, V16, V17, V28
V15, V18, V27, V29, V30
V2, V3, V4 - V11, V13, V14, V19 - V26
Counter-Current
V1, V12, V15, V18, V28
V16, V17, V27, V29, V30
V2, V3, V4 – V11, V13, V14, V19 – V26
Table 2: Valves Arrangement for Heat Exchanger Selection OPEN CLOSE Shell & Tube Heat Exchanger V4, V5, V19, V20 V6 - V11, V21 - V26
Spiral Heat Exchanger
V6, V7, V21, V22 V4, V5, V8 - V11, V19, V20, V23 - V26
Concentric Heat Exchanger
V8, V9, V23, V24 V4 - V7, V10, V11, V19 - V22, V25, V26
Plate Heat Exchanger V10, V11, V25, V26 V4 - V9, V19 - V24
Valve V3 : to vary hot water flowrate Valve V14 : to vary cold water flowrate Valve V2 and V13 : Flow bypass for water pump. These valves should be
partially opened all the time. If the water flowrates are not stable, reduce the bypass.
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
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c) Flow Measurements
FT1: Hot water flowrate FT2: Cold water flowrate The flowrates are digitally displayed in LPM.
d) Temperature Measurements
i) Counter-Current TT1: Hot water inlet temperature TT2: Hot water outlet temperature TT3: Cold water inlet temperature TT4: Cold water outlet temperature
ii) Co-Current TT1: Hot water inlet temperature TT2: Hot water outlet temperature TT3: Cold water outlet temperature TT4: Cold water inlet temperature
e) Operating Limits
Temperature : max. 70 ºC 2.4 Overall Dimensions
Height : 1.60 m Width : 2.00 m Depth : 0.60 m
2.5 General Requirements
Electrical : 415VAC/50Hz (3 phase) @ 50Amps Cooling water : Laboratory tap water, 20 LPM @ 2 m head Drainage point
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
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3.0 INSTALLATIONS AND COMMISIONING
3.1 Installation Procedures
1. The unit must be placed on rigid and level floor that has adequate strength to support its complete weight.
2. Connect the electrical socket 415-VAC/50Hz/3 phase power supply. 3. Connect hoses to the water supply and the drain ports.
3.2 Commissioning Procedures
1. Push the reset button on the Earth Leakage Circuit Breaker (ELCB) inside the
control panel after the main power supply is switched on. The ELCB should be kicked off, indicating that the ELCB is functioning properly. If not, get a trained electrician to inspect the electrical connection for any electrical leakage. The ELCB should be tested at least once a month.
2. Ensure that all valves are closed. 3. Fill up water in the tank 1 and tank 2 by opening valves V27 and V28. 4. Switch on the main switch. All indicators should lit-up. 5. Check all temperature readings on the indicators. The measurements should
be closed to the surrounding temperature. 6. Switch on the water heater switch on the control panel and set the set point of
the temperature controller to 50ºC according to section 2.3 (a). Notice that the water temperature in the hot water tank rises.
7. Set the valves to co-current Shell and Tube Heat Exchanger testing arrangement according to Section 2.3 (b).
8. Switch on the hot and the cold water pump (Pump 1 and Pump 2) and set the flowrates of both streams to 5 LPM by adjusting valves V3 and V14. Check that both pumps are functioning well.
9. Read the water flowrate on the water flow indicators (FT1 and FT2) and check that they are showing the correct readings.
10. Check all pipelines and Shell and tube Heat Exchangers and identify any leakage. Fix the leaking if there is any. Then, proceed to check the other heat exchangers.
11. Use the differential pressure transmitters (high range and low range) located on the bench to measure the pressure drop across the heat exchangers. Read the measurements on the indicators.
12. The unit is now ready for use.
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
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4.0 SUMMARY OF THEORY 4.1 Shell & Tube Heat Exchanger
Most chemical processes involve heat transfer to and from the process fluids. The most commonly used heat-transfer equipment is the shell and tube heat exchanger. If the fluids both flow in the same direction, as shown in Figure 2a, it is referred to as a parallel-flow type; if they flow in the opposite directions, a counterflow type.
T1, ms
T2
T2
t2ΔT2
T1
Heat Transfered
Flu
id T
emp
.
t1t2t1, mt
ΔT1
Figure 2a: Temperature profile for a parallel-flow heat exchanger.
Figure 2b: Temperature profile for a counterflow heat exchanger.
Figure 2c: Temperature profile for a 1:2 heat exchanger.
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
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Heat Balance For a parallel-flow shell and tube heat exchanger with one tube pass and one shell pass shown in Figure 2a, the heat balance is given as: mtCpt (t2 - t1) = msCps(T1 - T2) = q (1) Similarly, for the counterflow shell and tube heat exchanger with one tube pass and one shell pass shown in Figure 2b, the heat balance is given as: mtCpt (t2 - t1) = msCps(T1 - T2) = q (2) where, mt = mass flowrate of cold fluid in the tube (kgs-1) ms = mass flowrate of hot fluid in the shell (kgs-1) Cpt = specific heat of cold fluid in the tube (kJkg-1°C-1) Cps = specific heat of hot fluid in the shell (kJkg-1°C-1) t1, t2 = temperature of cold fluid entering/leaving the tube (°C) T1, T2 = temperature of hot fluid entering/leaving the shell (°C) q = heat exchange rate between fluid (kW)
Heat Transfer The general equation for heat transfer across the tube surface in a shell and tube heat exchanger is given by: q = Uo Ao Tm = Ui AiTm (3) where, Ao = outside area of the tube (m2) Ai = inside area of the tube (m2) Tm = mean temperature difference (°C) Uo = overall heat transfer coefficient based on the outside area of the tube (kWm-2°C-1) Ui = overall heat transfer coefficient based on the inside area of the tube (kWm-2°C-1) The coefficients Uo and Ui are given by:
ii
o
idi
o
w
ioo
odoo hdd
hdd
kddd
hhU
2)ln(111
(4)
and,
oo
i
odo
i
w
ioi
idii hdd
hdd
k
ddd
hhU
2
)ln(111 (5)
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
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where, ho = outside fluid film coefficient (kWm-2°C-1) hi = inside fluid film coefficient (kWm-2°C-1) hod = outside dirt coefficient (fouling factor) (kWm-2°C-1) hid = inside dirt coefficient (kWm-2°C-1) kw = thermal conductivity of the tube wall material (kWm-1°C-1) do = tube outside diameter (m) di = tube inside diameter (m) The mean temperature difference for both parallel and counterflow shell and tube heat exchanger with single shell pass and single tube pass is normally expressed in terms of log-mean temperature difference,
2
1
21
ln TT
TTTlm (6)
where, T1 and, T2 are as shown in Fig. 2a and Fig. 2b. For a more complex heat exchanger, such as 1:2 heat exchanger (Fig. 2c), an estimate of the true temperature difference is given by, Tm = Ft Tlm (7) where Ft is the temperature correction factor as a function of two dimensionless temperature ratios R and S:
)()(
12
21
ttTT
R
and, )()(
11
12
tTtt
S
(8)
Having calculated R and S, then Ft is determined from the standard correction factor figures. (Figure C.1 in Appendix C) Tube-side Heat-transfer Coefficient, hi For turbulent flow, Sieder-Tate equation can be used: 14.033.08.0 )/(PrRe wfCNu (9) where, Re = Reynolds Number = fetfetf dGdu //
Nu = Nusselt Number = fei kdh /
Pr = Prandtl Number = ffp kC /
de = equivalent (or hydraulic) diameter (m) = 4 x (cross-sectional area of flow) / wetted perimeter = di for tubes
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
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Gt = mass velocity, mass flow per unit area (kg/ s.m2) µf = fluid viscosity of bulk fluid temperature (Nsm-2) µw = fluid viscosity at the wall (Nsm-2) ρf = fluid density (kgm-3) ut = fluid velocity in tube (ms-1) Cp = fluid specific heat, heat capacity (J/kg°C) C = 0.023 for non-viscous liquids = 0.027 for viscous liquids fk = Fluid thermal conductivity (W/m°C) For laminar flow (Re < 2000), the following correlation is used:
14.033.033.0 )/(Pr).(Re86.1 wfe LdNu (10) where, L = the tube length (m) Tube-side Pressure Drop, Pt The tube-side pressure drop is given by:
2
5.2)/(82tfm
wifpt
udLjNP
(11)
where, Pt = tube-side pressure drop (N/m2) Np = number of tube-side passes
jf = tube dimensionless friction factor (Figure C.3 in Appendix C)
L = length of one tube, (m) ut = tube-side velocity (m/s) m = 0.25 for laminar, Re < 2100 = 0.14 for turbulent, Re > 2100 Shell-side Heat-transfer Coefficient, hs (Kern’s Method) In order to determine the heat transfer coefficient for fluid film in shell, first calculate the cross-sectional area of flow As for hypothetical row of tubes of the shell as follows:
tBsots plDdpA /)( (12) where, do = tube outside diameter (m) pt = tube pitch (m) Ds = shell inside diameter (m) lB = distance between baffle (m)
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
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Then, the shell-side mass velocity, Gs and linear velocity, us are calculated as follows:: Gs = W s /A s (13)
us = G s /ρ f (14) where, W s = Fluid flowrate on the shell-side (kg/s) ρ f = shell-side fluid density (kg/m3) The shell equivalent diameter, de is given by:
22
22
785.027.1
)4/(4
oto
o
ote
dpd
ddp
d
(15)
(For square pitch arrangement)
22
2
917.010.1
2/
4/21
87.02
4
oto
o
ott
e
dpd
d
dpp
d
(16)
(For equilateral triangular pitch arrangement) Thus, Reynolds number in shell is given by: Re = Gs de / µf = us de ρ f / µf (17) Baffle cut, Bc, is used to specify the dimensions of a segmental baffle. It is the height of the segment removed to form the baffle, expressed as a percentage of the baffle disc diameter. Using this Reynolds number and given Bc value, the heat transfer factor, jh value is determined from Figure C.4. Then, the heat transfer coefficient for fluid film in shell is calculated from:
14.033.0PrRe/ wfhfes jkdhNu (18)
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
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Shell-side Pressure Drop, Ps (Kern’s Method) The shell-side pressure drop is given by:
14.02
2)/)(/(8 wf
sBesfs
ulLdDjP
(19)
where, ΔPs = shell pressure drop (N/m2) jf = shell dimensionless friction factor from Figure C.5 lB = distance between baffle (m) us = shell-side velocity (m/s) Shell-side Heat-transfer Coefficient, hs (Bell’s Method) The shell-side heat transfer coefficient is given by:
Lbwnocs FFFFhh (20)
where, hoc = heat transfer coefficient calculated for cross-flow over an ideal tube bank, no leakage or by-passing, Fn = correction factor to allow for the effect of the number of vertical tube rows, Fw = window effect correction factor, Fb = by-pass stream correction factor, FL = leakage correction factor. The ideal cross-flow heat transfer coefficient hoc is given by,
14.033.0 )(PrRe wfhf
ooc jk
dh (21)
where, Re = Gs do/ µf = us do ρ f / µf Heat-transfer coefficient for an ideal cross-flow tube banks can be calculated using the heat transfer factors, hj from Figure C.6 in Appendix C. The correction factor Fn is determined as follows: a) For Re > 2000, turbulent, take Fn from Figure C.7 b) For Re > 100 to 2000, transition region, take Fn = 1.0 c) For Re < 100, laminar region, 18.0)( cn NF
where cN = numbers of rows crossed in series from end to end of the
shell.
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
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The window correction factor Fw is plotted against Rw as shown in Figure C.8 where Rw is the ratio of the numbers of tubes in the window zones to the total number in the bundle. The by-pass correction factor Fb is,
2/ for /21exp 31cvscvs
s
bb NNNN
A
AF
(22)
where, = 1.5 for laminar flow, Re < 100, = 1.35 for transitional and turbulent flow Re > 100 Ab = clearance area between the bundle and the shell As = maximum area for cross-flow
Ns = number of sealing strips encountered by the by-pass stream in the cross-flow zone Ncv = the number of constrictions, tube rows, encountered in the cross-flow section.
If there is no sealing strips used, Fb is obtained from Figure C.9. The leakage correction factor FL is,
LsbtbLL AAAF /21 (23)
where L = a factor obtained from Figure C.10. Atb = tube-to-baffle clearance area, per baffle, Asb = shell-to-baffle clearance area, per baffle, AL = total leakage area, Atb + Asb
Shell-side Pressure Drop, Ps (Bell’s Method) The total shell-side pressure drop is the sum of pressure drop in cross-flow and window zones, determined separately. The pressure drop in the cross-flow zones ∆Pc between the baffle tips is calculated from the correlations for ideal tube banks, and corrected for leakage and bypassing. Lbic FFPP (24)
where, Pi = pressure drop calculated for an equivalent ideal tube bank,
= 14.02
28
ws
cvf
uNj
(25)
Ncv = number of tube rows crossed (in the cross-flow region),
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
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us = shell-side velocity, based on the clearance area As at the bundle equator,
jf = friction factor from Figure C.11 for Re calculated with us bF = by-pass correction factor,
LF = leakage correction factor. Calculate bF from Equation 21 with = 5.0 for laminar region, Re < 100 and =
4.0 for transition and turbulent region, Re > 100. If no sealing strips used, take
bF from Figure C.12.
Calculate LF from Equation 22 taking L from Figure C.13. The window-zone pressure drop is,
2)6.02( 2zwvLw uNFP (26)
where, uz = geometric mean velocity, = swuu
uw = velocity in the window zone = ws AW ,
Ws = shell-side fluid mass flow (kg/s), Nwv = number of restrictions for cross-flow in window zone, approximately equal to the number of tube rows.
The end-zone pressure drop is,
bcvcvwvie FNNNPP (27)
Thus, the total shell-side pressure drop is the sum of pressure drops over all the zones in series from inlet to outlet:
wbcbe
bbs
PNPNP
NNP
)1(2=
zones) (window + zones) (crossflow)1( + zones) 2(end
(28) where, Nb = number of baffles = (L/ lB – 1) (29) Shell and Bundle Geometry The shell and bundle geometry described below shall be used for calculating the correction factors above. where
Hc = baffle cut height = Bc x Ds, where Bc is the baffle cut as a fraction,
Hb = height from the baffle chord to the top of the tube bundle,
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
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Bb = “bundle cut” = Hb / Db, b = angle subtended by the baffle chord (rads), Db = bundle diameter Subsequently,
)5.0(2/ csbb BDDH (30)
tbbcv pHDN /)2( (31)
tbwv pHN / (32)
where tp = vertical tube pitch,
= pt for square pitch, = 0.87 pt for equilateral triangular pitch. The number of tubes in a window zone Nw is given by:
atw RNN (33)
where aR can be obtained from Figure C.15, for the appropriate “bundle cut”, Bb.
The number of tubes in a cross-flow zone Nc is given by, Nc=Nt – 2 Nw (34) and Rw=2 Nw / Nt (35)
)4()4( 22owsaw dNDRA (36)
where Ra is obtained from Figure C.15 for the appropriate baffle cut, Bc.
)()2( wtottb NNdcA (37)
where ct is the diametrical tube-to-baffle clearance, typically 0.8mm.
)2()2( bsssb DcA (38)
where cs is the baffle-to-shell clearance and θb can be obtained from Figure C.15 for the appropriate baffle cut, Bc. Ab=lB (Ds – Db) (39)
where lB is the baffle spacing.
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
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4.2 Spiral Heat Exchanger A Spiral Heat Exchanger is actually a form of concentric heat exchanger (Please refer to Section 3.3), but coiled in such a way that the effectiveness of the heat transfer is increased. The correlation for forced convective heat transfer in conduits can be used to predict the heat transfer coefficient in the annulus, with the following modification of the equivalent diameter.
de = perimeterwetted
areationalcross sec4 (40)
= 123
21
22
234
4
ddd
ddd
= 123
21
22
23
ddd
ddd
where, d3 = Shell Inside Diameter d2 = Coil Inside Diameter d1 = Coil Outside Diameter
4.3 Concentric (Double Pipe) Heat Exchanger A concentric (double pipe) heat exchanger is actually the simplest form of shell and tube heat exchanger. The correlation for forced convective heat transfer in conduits (Equation 39) can be used to predict the heat transfer coefficient in the annulus, using the appropriate equivalent diameter:
12
12
21
224
4
4
dd
dd
dd
perimeterwettedareationalcrossx
de
sec
(41)
where d2 = inside diameter of the outer pipe d1 = outside diameter of the inner pipe
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
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4.4 Plate Heat Exchanger
Plate heat exchangers are used extensively in the food and beverage industries due to the fact that they are easily taken apart for cleaning and inspection. Their used in other industries will depend on the relative cost as compared to other types of heat exchanger such as the shell and tube heat exchangers. The general equation for heat transfer across a surface is:
Q = U A Tm (42)
where, Q = heat transfer per unit time, W U = the overall heat transfer coefficient, W/m2°C A = heat transfer area, m2. Tm = the mean temperature difference, the temperature driving force, °C For counter-current arrangement, the temperature difference correction factor Ft will be close to 1. Therefore,
Tm = Tlm (43) where,
12
21
1221
lntT
tTtTtT
Tlm
(44)
Tlm = log mean temperature difference T1 = inlet hot water temperature T2 = outlet hot water temperature t1 = inlet cold water temperature t2 = outlet cold water temperature From heat balance, Q = m Cp T (45) where, m = mass flowrate of fluid in the plates (kgs-1) Ct = specific heat of fluid in the plates (kJkg-1°C-1) T = temperature difference of fluid entering/leaving the plates (°C) One may use the equation for forced-convective heat transfer in conduits to the plate heat exchangers by applying appropriate constant C and indices a, b, and c. For the purpose of designing the exchanger, a typical equation as given below is useful for making a preliminary estimate of the area required.
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
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14.0
4.065.0 PrRe26.0
w
f
f
ep
k
dh
(46)
where, hp = plate film coefficient.
epdG
Re (47)
and
f
p
k
C Pr (48)
where, Gp = mass flow rate per unit cross-sectional area = W/Af Af = cross-sectional area for flow de = equivalent (hydraulic) diameter = twice the gap between the plates Cp = fluid specific heat, heat capacity The flow arrangement in a plate heat exchanger is much closer to true counter-current flow than in a shell and tube heat exchanger. Therefore, the mean temperature difference will generally be higher in a plate heat exchanger. For a series arrangement the logarithmic mean temperature difference correction factor Ft will be close to 1. The plate pressure drop can be estimated using a form of the equation for flow in a conduit:
28
2p
e
pfp
u
d
LjP
(49)
where, Lp = the path length up = Gp/. For preliminary calculations the following relationship can be used for turbulent flow:
3.0Re25.1 fj (50) The transition from laminar to turbulent flow will normally occur at a Reynolds number of 100 to 400, depending on the plate design. With some designs, turbulence can be achieved at very low Reynolds numbers, which makes plate heat exchangers very suitable for use with viscous fluid.
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
20
Figure 3: Single pass flow plate heat exchanger diagram
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
21
5.0 GENERAL OPERATING PROCEDURES
5.1 General Start-up Procedures
1. Perform a quick inspection to make sure that the equipment is in a proper working condition.
2. Be sure that all valves are initially closed, except V1 and V12. 3. Fill up hot water tank via a water supply hose connected to valve V27. Once
the tank is full, close the valve. 4. Fill up the cold-water tank by opening valve V 28 and leave the valve opened
for continues water supply. 5. Connect a drain hose to the cold water drain point. 6. Switch on main power. Switch on the heater for the hot water tank and set
point the temperature controller to 50 C. Note: Recommended maximum temperature controller set point is 70 C
7. Allow the water temperature in the hot water tank to reach the set-point. 8. The equipment is now ready to be run.
5.2 General Shut-down Procedures
1. Switch off heater. Wait until the hot water temperature drops below 40°C. 2. Switch off pump P1 and pump P2. 3. Switch off main power. 4. Drain off all water in the process lines. Retain water in the hot and cold water
tanks for next laboratory session. 5. Close all valves.
Note: If the equipment is not to be run for a long period, drain all water completely.
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
22
6.0 EXPERIMENTAL PROCEDURES
6.1 Experiment 1.A: Counter-Current Shell & Tube Heat Exchanger
In this experiment, cold water enters the shell at room temperature while hot water enters the tubes in the opposite direction. Students shall vary the hot water and cold water flow rates and record the inlet and outlet temperatures of both the hot water and cold water streams at steady state. Procedure: 1. Perform general start-up procedures in Section 4.1. 2. Switch the valves to counter-current Shell & Tube Heat Exchanger
arrangement (Please refer to Section 2.3). 3. Switch on pumps P1 and P2. 4. Open and adjust valves V3 and V14 to obtain the desired flowrates for hot
water and cold water streams, respectively. 5. Allow the system to reach steady state for 10 minutes. 6. Record FT1, FT2, TT1, TT2, TT3 and TT4. 7. Record pressure drop measurements for shell-side and tube-side for pressure
drop studies. 8. Repeat steps 4 to 7 for different combinations of flowrate FT1 and FT2 as in
the results sheet. 9. Switch off pumps P1 and P2 after the completion of experiment. 10. Proceed to the next experiment or shut-down the equipment. Results:
FT 1 (LPM)
FT 2 (LPM)
TT 1 (°C)
TT 2 (°C)
TT 3 (°C)
TT 4 (°C)
DPT1 (mmH2O)
DPT2 (mmH2O)
10 2 10 4 10 6 10 8 10 10
FT 1
(LPM) FT 2
(LPM) TT 1 (°C)
TT 2 (°C)
TT 3 (°C)
TT 4 (°C)
DPT1 (mmH2O)
DPT2 (mmH2O)
2 10 4 10 6 10 8 10 10 10
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
23
Assignments: 1. Calculate the heat transfer and heat loss for energy balance study. 2. Calculate the LMTD. 3. Calculate heat transfer coefficients. 4. Calculate the pressure drop and compare with the experimental result. 5. Perform temperature profile study and the flow rate effects on heat transfer.
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
24
6.2 Experiment 1.B: Co-Current Shell & Tube Heat Exchanger
In this experiment, cold water enters the shell at room temperature while hot water enters the tubes in the same direction. Students shall vary the hot water and cold water flow rates and record the inlet and outlet temperatures of both the hot water and cold water streams at steady state. Procedure: 1. Perform general start-up procedures in Section 4.1. 2. Switch the valves to co-current Shell & Tube Heat Exchanger arrangement
(Please refer to Section 2.3). 3. Switch on pumps P1 and P2. 4. If there is air trap in the shell-side, switch the valves to counter-current and
bleed the air with high water flowrate. Then switch the valves position back to co-current position.
5. Open and adjust valves V3 and V14 to obtain the desired flowrates for hot water and cold water streams, respectively.
6. Allow the system to reach steady state for 10 minutes. 7. Record FT1, FT2, TT1, TT2, TT3 and TT4. 8. Record pressure drop measurements for shell-side and tube-side for pressure
drop studies. 9. Repeat steps 5 to 8 for different combinations of flowrate FT1 and FT2 as in
the results sheet. 10. Switch off pumps P1 and P2 after the completion of experiment. 11. Proceed to the next experiment or shut-down the equipment.
Results:
FT 1 (LPM)
FT 2 (LPM)
TT 1 (°C)
TT 2 (°C)
TT 3 (°C)
TT 4 (°C)
DPT1 (mmH2O)
DPT2 (mmH2O)
10 2 10 4 10 6 10 8 10 10
FT 1 (LPM)
FT 2 (LPM)
TT 1 (°C)
TT 2 (°C)
TT 3 (°C)
TT 4 (°C)
DPT1 (mmH2O)
DPT2 (mmH2O)
2 10 4 10 6 10 8 10 10 10
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
25
Assignments: 1. Calculate the heat transfer and heat loss for energy balance study. 2. Calculate the LMTD. 3. Calculate heat transfer coefficients. 4. Calculate the pressure drop and compare with the experimental result. 5. Perform temperature profile study and the flow rate effects on heat transfer.
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
26
6.3 Experiment 2.A: Counter-Current Spiral Heat Exchanger
In this experiment, cold water enters the shell at room temperature while hot water enters the tubes in the opposite direction. Students shall vary the hot water and cold water flow rates and record accordingly the inlet and outlet temperatures of both the hot water and cold water streams at steady state. Procedure: 1. Perform general start-up procedures in Section 4.1. 2. Switch the valves to counter-current Spiral Heat Exchanger arrangement
(Please refer to Section 2.3). 3. Switch on pumps P1 and P2. 4. Open and adjust valves V3 and V14 to obtain the desired flowrates for hot
water and cold water streams, respectively. 5. Allow the system to reach steady state for 10 minutes. 6. Record FT1, FT2, TT1, TT2, TT3 and TT4. 7. Record pressure drop measurements for shell-side and tube-side for pressure
drop studies. 8. Repeat steps 4 to 7 for different combinations of flowrate FT1 and FT2 as in
the results sheet. 9. Switch off pumps P1 and P2 after the completion of experiment. 10. Proceed to the next experiment or shut-down the equipment.
Results:
FT 1 (LPM)
FT 2 (LPM)
TT 1 (°C)
TT 2 (°C)
TT 3 (°C)
TT 4 (°C)
5.0 2.0 5.0 3.0 5.0 4.0 5.0 5.0
FT 1
(LPM) FT 2
(LPM) TT 1 (°C)
TT 2 (°C)
TT 3 (°C)
TT 4 (°C)
2.0 5.0 3.0 5.0 4.0 5.0 5.0 5.0
Assignments: 1. Calculate the heat transfer and heat loss for energy balance study. 2. Calculate the LMTD. 3. Calculate heat transfer coefficients. 4. Perform temperature profile study and the flow rate effects on heat transfer.
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
27
6.4 Experiment 2.B: Co-Current Spiral Heat Exchanger
In this experiment, cold water enters the shell at room temperature while hot water enters the tubes in the same direction. Students shall vary the hot water and cold water flow rates and record accordingly the inlet and outlet temperatures of both the hot water and cold water streams at steady state. Procedure: 1. Perform general start-up procedures in Section 4.1. 2. Switch the valves to co-current Spiral Heat Exchanger arrangement (Please
refer to Section 2.3). 3. Switch on pumps P1 and P2. 4. Open and adjust valves V3 and V14 to obtain the desired flowrates for hot
water and cold water streams, respectively. 5. Allow the system to reach steady state for 10 minutes. 6. Record FT1, FT2, TT1, TT2, TT3 and TT4. 7. Record pressure drop measurements for shell-side and tube-side for pressure
drop studies. 8. Repeat steps 4 to 7 for different combinations of flowrate FT1 and FT2 as in
the results sheet. 9. Switch off pumps P1 and P2 after the completion of experiment. 10. Proceed to the next experiment or shut-down the equipment.
Results:
FT 1 (LPM)
FT 2 (LPM)
TT 1 (°C)
TT 2 (°C)
TT 3 (°C)
TT 4 (°C)
5.0 2.0 5.0 3.0 5.0 4.0 5.0 5.0
FT 1
(LPM) FT 2
(LPM) TT 1 (°C)
TT 2 (°C)
TT 3 (°C)
TT 4 (°C)
2.0 5.0 3.0 5.0 4.0 5.0 5.0 5.0
Assignments: 1. Calculate the heat transfer and heat loss for energy balance study. 2. Calculate the LMTD. 3. Calculate heat transfer coefficients. 4. Perform temperature profile study and the flow rate effects on heat transfer.
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
28
6.5 Experiment 3.A: Counter-Current Concentric Heat Exchanger
In this experiment, cold water enters the shell at room temperature while hot water enters the tubes in the opposite direction. Students shall vary the hot water and cold water flow rates and record the inlet and outlet temperatures of both the hot water and cold water streams at steady state. Procedure: 1. Perform general start-up procedures in Section 4.1. 2. Switch the valves to counter-current Concentric Heat Exchanger arrangement
(Please refer to Section 2.3). 3. Switch on pumps P1 and P2. 4. Open and adjust valves V3 and V14 to obtain the desired flowrates for hot
water and cold water streams, respectively. 5. Allow the system to reach steady state for 10 minutes. 6. Record FT1, FT2, TT1, TT2, TT3 and TT4. 7. Record pressure drop measurements for shell-side and tube-side for pressure
drop studies. 8. Repeat steps 4 to 7 for different combinations of flowrate FT1 and FT2 as in
the results sheet. 9. Switch off pumps P1 and P2 after the completion of experiment. 10. Proceed to the next experiment or shut-down the equipment.
Results:
FT 1 (LPM)
FT 2 (LPM)
TT 1 (°C)
TT 2 (°C)
TT 3 (°C)
TT 4 (°C)
10.0 2.0 10.0 4.0 10.0 6.0 10.0 8.0 10.0 10.0
FT 1 (LPM)
FT 2 (LPM)
TT 1 (°C)
TT 2 (°C)
TT 3 (°C)
TT 4 (°C)
2.0 10.0 4.0 10.0 6.0 10.0 8.0 10.0
10.0 10.0 Assignments: 1. Calculate the heat transfer and heat loss for energy balance study. 2. Calculate the LMTD. 3. Calculate heat transfer coefficients. 4. Perform temperature profile study and the flow rate effects on heat transfer.
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
29
6.6 Experiment 3.B: Co-Current Concentric Heat Exchanger
In this experiment, cold water enters the shell at room temperature while hot water enters the tubes in the same direction. Students shall vary the hot water and cold water flow rates and record the inlet and outlet temperatures of both the hot water and cold water streams at steady state. Procedure: 1. Perform general start-up procedures in Section 4.1. 2. Switch the valves to co-current Concentric Heat Exchanger arrangement
(Please refer to Section 2.3). 3. Switch on pumps P1 and P2. 4. Open and adjust valves V3 and V14 to obtain the desired flowrates for hot
water and cold water streams, respectively. 5. Allow the system to reach steady state for 10 minutes. 6. Record FT1, FT2, TT1, TT2, TT3 and TT4. 7. Record pressure drop measurements for shell-side and tube-side for pressure
drop studies. 8. Repeat steps 4 to 7 for different combinations of flowrate FT1 and FT2 as in
the results sheet. 9. Switch off pumps P1 and P2 after the completion of experiment. 10. Proceed to the next experiment or shut-down the equipment.
Results:
FT 1 (LPM)
FT 2 (LPM)
TT 1 (°C)
TT 2 (°C)
TT 3 (°C)
TT 4 (°C)
10.0 2.0 10.0 4.0 10.0 6.0 10.0 8.0 10.0 10.0
FT 1
(LPM) FT 2
(LPM) TT 1 (°C)
TT 2 (°C)
TT 3 (°C)
TT 4 (°C)
2.0 10.0 4.0 10.0 6.0 10.0 8.0 10.0
10.0 10.0 Assignments: 1. Calculate the heat transfer and heat loss for energy balance study. 2. Calculate the LMTD. 3. Calculate heat transfer coefficients. 4. Perform temperature profile study and the flow rate effects on heat transfer.
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
30
6.7 Experiment 4.A: Counter-Current Plate Heat Exchanger
In this experiment, cold water enters the heat exchanger at room temperature while hot water enters the heat exchanger in the opposite direction. Students shall vary the hot water and cold water flow rates and record the inlet and outlet temperatures of both the hot water and cold water streams at steady state. Procedure: 1. Perform general start-up procedures in Section 4.1. 2. Switch the valves to counter-current Plate Heat Exchanger arrangement
(Please refer to Section 2.3). 3. Switch on pumps P1 and P2. 4. Open and adjust valves V3 and V14 to obtain the desired flowrates for hot
water and cold water streams, respectively. 5. Allow the system to reach steady state for 10 minutes. 6. Record FT1, FT2, TT1, TT2, TT3 and TT4. 7. Record pressure drop measurements for shell-side and tube-side for pressure
drop studies. 8. Repeat steps 4 to 7 for different combinations of flowrate FT1 and FT2 as in
the results sheet. 9. Switch off pumps P1 and P2 after the completion of experiment. 10. Proceed to the next experiment or shut-down the equipment.
Results:
FT 1 (LPM)
FT 2 (LPM)
TT 1 (°C)
TT 2 (°C)
TT 3 (°C)
TT 4 (°C)
8.0 2.0 8.0 4.0 8.0 6.0 8.0 8.0 8.0 10.0
FT 1
(LPM) FT 2
(LPM) TT 1 (°C)
TT 2 (°C)
TT 3 (°C)
TT 4 (°C)
2.0 8.0 4.0 8.0 6.0 8.0 8.0 8.0
10.0 8.0 Assignments: 1. Calculate the heat transfer and heat loss for energy balance study. 2. Calculate the LMTD. 3. Calculate heat transfer coefficients. 4. Perform temperature profile study and the flow rate effects on heat transfer.
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
31
6.8 Experiment 4.B: Co-Current Plate Heat Exchanger
In this experiment, cold water enters the heat exchanger at room temperature while hot water enters in the same direction. Students shall vary the hot water and cold water flow rates and record accordingly the inlet and outlet temperatures of both the hot water and cold water streams at steady state. Procedure: 1. Perform general start-up procedures in Section 4.1. 2. Switch the valves to co-current Plate Heat Exchanger arrangement (Please
refer to Section 2.3). 3. Switch on pumps P1 and P2. 4. Open and adjust valves V3 and V14 to obtain the desired flowrates for hot
water and cold water streams, respectively. 5. Allow the system to reach steady state for 10 minutes. 6. Record FT1, FT2, TT1, TT2, TT3 and TT4. 7. Record pressure drop measurements for shell-side and tube-side for pressure
drop studies. 8. Repeat steps 4 to 7 for different combinations of flowrate FT1 and FT2 as in
the results sheet. 9. Switch off pumps P1 and P2 after the completion of experiment. 10. Proceed to the next experiment or shut-down the equipment.
Results:
FT 1 (LPM)
FT 2 (LPM)
TT 1 (°C)
TT 2 (°C)
TT 3 (°C)
TT 4 (°C)
7.5 2.0 7.5 4.0 7.5 6.0 7.5 8.0 7.5 9.5
FT 1 (LPM)
FT 2 (LPM)
TT 1 (°C)
TT 2 (°C)
TT 3 (°C)
TT 4 (°C)
7.5 2.0 7.5 4.0 7.5 6.0 7.5 8.0 7.5 9.5
Assignments: 1. Calculate the heat transfer and heat loss for energy balance study. 2. Calculate the LMTD. 3. Calculate heat transfer coefficients. 4. Perform temperature profile study and the flow rate effects on heat transfer.
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
32
7.0 EQUIPMENT MAINTENANCE
1. Restore the system to operating conditions after any repair job. 2. Only properly trained personnel shall be allowed to carry out any servicing. 3. Before servicing, shut down the whole operation and let the system to cool down.
8.0 SAFETY PRECAUTION
1. The unit must be operated under the supervision of trained personnel. 2. All operating instructions supplied with the unit must be read and understood before
attempting to operate the unit. 3. Always check and rectify any leak. 4. Always make sure that the heater is fully immersed in the water. 5. Do not touch the hot components of the unit. 6. Be extremely careful when handling liquid at high temperature. 7. Always switch off the heater and allow the liquid to cool down before draining.
SOLTEQ® HEAT EXCHANGER TRAINING APPARATUS (Model: HE 158C) _______________________________
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9.0 REFERENCES
Chopey, N.P. “Handbook of Chemical Engineering Calculations (2nd Edition)”, McGraw-Hill, 1994.
Coulson, J.M. and Richardson, J.F. “Chemical Engineering, Volume 1 (3rd Edition)”, Pergamon Press, 1977.
Coulson, J.M. and Richardson, J.F. “Chemical Engineering, Volume 6 (Revised 3rd Edition)”, Butterworth-Heinemann, 1996.
Kern, D.Q. “Process Heat Transfer (Int’l Edition)”, McGraw-Hill, 1965.
Perry, R.H., Green, D.W. and Maloney, J.O. “Perry’s Chemical Engineering Handbook (6th Edition)”, McGraw-Hill, 1984.
Experiment 1.A: Co-Current Shell & Tube Heat Exchanger
FI 1 (LPM)
FI 2 (LPM)
TT 1 (°C)
TT 2 (°C)
TT 3 (°C)
TT 4 (°C)
DPT1 (mmH2O)
DPT2 (mmH2O)
Experiment 1.B: Counter-Current Shell & Tube Heat Exchanger
FI 1 (LPM)
FI 2 (LPM)
TT 1 (°C)
TT 2 (°C)
TT 3 (°C)
TT 4 (°C)
DPT1 (mmH2O)
DPT2 (mmH2O)
Experiment 2.A: Co-Current Helical Coil Heat Exchanger
Experiment 2.B: Counter-Current Helical Coil Heat Exchanger
FI 1 (LPM)
FI 2 (LPM)
TT 1 (°C)
TT 2 (°C)
TT 3 (°C)
TT 4 (°C)
FI 1 (LPM)
FI 2 (LPM)
TT 1 (°C)
TT 2 (°C)
TT 3 (°C)
TT 4 (°C)
Experiment 3.A: Co-Current Concentric Heat Exchanger
FI 1 (LPM)
FI 2 (LPM)
TT 1 (°C)
TT 2 (°C)
TT 3 (°C)
TT 4 (°C)
Experiment 3.B: Counter-Current Concentric Heat Exchanger
FI 1 (LPM)
FI 2 (LPM)
TT 1 (°C)
TT 2 (°C)
TT 3 (°C)
TT 4 (°C)
Experiment 4.A: Co-Current Plate Heat Exchanger
FI 1 (LPM)
FI 2 (LPM)
TT 1 (°C)
TT 2 (°C)
TT 3 (°C)
TT 4 (°C)
Experiment 4.B: Counter-Current Plate Heat Exchanger
FI 1 (LPM)
FI 2 (LPM)
TT 1 (°C)
TT 2 (°C)
TT 3 (°C)
TT 4 (°C)
Table B.1: Conversion Factors for Single Terms
To convert from To Multiply by Btu (thermochemical) Calorie (thermochemical) Foot lbf Foot poundal Kilowatt hour Watt hour
Energy Joule Joule Joule Joule Joule Joule
1054.35026448 4.184 1.3558179 0.042140110 3.6 x 106
3600
Dyne Kilogram force (kgf) Ounce force (avoirdupois) Pound force, lbf (avoirdupois) Poundal
Force Newton Newton Newton Newton Newton
1.0 x 10-5
9.80665 0.27801385 4.44822161526 0.1382549543
Angstrom Foot Inch Micron Mil Mile (U.S state) Yard
Length Meter Meter Meter Meter Meter Meter Meter
1.0 x 10-10
0.3048 0.0254
1.0 x 10-6 2.54 x 10-5
1609.344 0.9144
Gram Kgf second2 meter Lbm (avoirdupois) Ounce mass (avoirdupois) Ton (long) Ton (metric) Ton (short, 2000 pound)
Mass Kilogram Kilogram Kilogram Kilogram Kilogram Kilogram Kilogram
1.0 x 10-3 9.80665 0.45359237 0.028349523 1016.0469 1000 907.18474
Celcius Fahrenheit Fahrenheit Kelvin Rankine
Temperature Kelvin Celcius Kelvin Celcius Kelvin
K = C + 273.15
C = 9
5 ( F – 32 )
C = 9
5 ( F – 459.67 )
C = 9
5 F – 273.15
C = 9
5 R
To convert from To Multiply by Btu (thermochemical) Calorie (thermochemical) Foot lbf Foot poundal Kilowatt hour Watt hour
Energy Joule Joule Joule Joule Joule Joule
1054.35026448 4.184 1.3558179 0.042140110 3.6 x 106
3600
Dyne Kilogram force (kgf) Ounce force (avoirdupois) Pound force, lbf (avoirdupois) Poundal
Force Newton Newton Newton Newton Newton
1.0 x 10-5
9.80665 0.27801385 4.44822161526 0.1382549543
Angstrom Foot Inch Micron Mil Mile (U.S state) Yard
Length Meter Meter Meter Meter Meter Meter Meter
Gram Kgf second2 meter Lbm (avoirdupois) Ounce mass (avoirdupois) Ton (long) Ton (metric) Ton (short, 2000 pound)
Mass Kilogram Kilogram Kilogram Kilogram Kilogram Kilogram Kilogram
1.0 x 10-3 9.80665 0.45359237 0.028349523 1016.0469 1000 907.18474
Celcius Fahrenheit Fahrenheit Kelvin Rankine
Temperature Kelvin Celcius Kelvin Celcius Kelvin
K = C + 273.15
C = 9
5 ( F – 32 )
C = 9
5 ( F – 459.67 )
C = 9
5 F – 273.15
C = 9
5 R
Table B.2: Conversion Factors for Compound Terms
To convert from To Multiply by Foot/ second2
Inch/second2
Acceleration Meter/ second2 Meter/ second2
0.3048 0.0254
Gram/ centimeter Lbm/ foot3 Slug/ foot3
Density Kilogram/ meter3 Kilogram/ meter3 Kilogram/ meter3
1000 16.018463 515.379
Btu/ foot2 – hour *Calories/ second Watt/ centimeter2
Energy/ Area-Time Watt/ meter3
Watt/ meter3
Watt/ meter3
3.1524808 697.33333 10000
Btu/ second Calories/ second Foot lbf/ second horsepower (5550 ft lbf/ second) horsepower (electric) horsepower (metric)
Power Watt Watt Watt Watt Watt Watt
1054.3502644 4.184 1.3558179 745.69987 746.00 735.499
Atmosphere Bar Milimeter of mercury (0ºC) Centimeter of water (4ºC) Dyne/ centimeter2 Kgf/ centimeter2 Lbf/ inch2 (psi) Pascal Torr (0ºC)
Pressure Newton/ meter2
Newton/ meter2 Newton/ meter2 Newton/ meter2 Newton/ meter2 Newton/ meter2 Newton/ meter2 Newton/ meter2 Newton/ meter2
1.01325 x 105 1.0 x 105 133.322 98.0638 0.100 98066.5 6894.7572 1.00 133.322
Foot/ second Kilometer/ hour Knot (international) Mile/ hour (U.S state)
Speed Meter/ second Meter/ second Meter/ second Meter/ second
0.3048 0.27777778 0.51444444 0.44704
Btu inch/ foot2 Second-ºF Btu/ food-hour ºF
Thermal Conductivity Joule/ meter-second-K Joule/ meter-second-K
518.87315 1.7295771
Table B.3: Conversion Factors for Compound Terms (Continued)
To convert from To Multiply by Centipoises Centistoke Foot2/ second Lbm/ food-second Lbf second/ foot2 Poise Poundal second/ ft2 Slug/ foot-second Stoke
Viscosity Newton second/ meter2 Meter2/ second Meter2/ second Newton second/ meter2
Newton second/ meter2 Newton second/ meter2 Newton second/ meter2 Newton second/ meter2 Meter2/ second
1.0 x 10-3 1.0 x 10-6 0.09290304 1.4881639 47.880258 0.10 1.4881639 47.880258 1.0 x 10-4
Fluid ounce (U.S) Foot3 Gallon (British) Gallon (U.S dry) Gallon (U.S liquid) Liquid (H2O at 4ºC) Liter (SI) Pint (U.S liquid) Quart (U.S liquid) Yard3
Volume Meter3
Meter3
Meter3
Meter3
Meter3
Meter3
Meter3
Meter3
Meter3
Meter3
2.95735295 x 10-5 0.0283168465 4.546087 x 10-3 4.40488377 x 10-3 3.78541178 x 10-3 1.000028 x 10-3 1.0 x 10-3 4.73176473 x 10-4 9.4635295 x 10-4 0.764554857
Table B.4: Heat Transfer Properties of Liquid Water, SI Units
T (ºC) T (K) ρ (kg/m3) cp (kJ/kg.K) k (W/m.K) NPr μ x 103 (Pa.s)
0.0 273.2 999.6 4.229 0.5694 13.3 1.786
15.6 288.8 998.0 4.187 0.5884 8.07 1.131
26.7 299.9 996.4 4.183 0.6109 5.89 0.860
37.8 311.0 994.7 4.183 0.6283 4.51 0.682
65.6 338.8 981.9 4.187 0.6629 2.72 0.432
93.3 366.5 962.7 4.229 0.6802 1.91 0.3066
121.1 394.3 943.5 4.271 0.6836 1.49 0.2381
148.9 422.1 917.9 4.312 0.6836 1.22 0.1935
204.4 477.6 858.6 4.522 0.6611 0.950 0.1384
260.0 533.2 784.9 4.982 0.6040 0.859 0.1042
315.6 588.8 679.2 6.322 0.5071 1.07 0.0862
Experiment 1.A: Counter-Current Shell & Tube Heat Exchanger
TYPICAL CHEMICAL DATA
Hot water
Density: 988.18 kg/m3
Heat capacity: 4175.00 J/kg.K
Thermal cond: 0.6436 W/m.K
Viscosity: 0.0005494 Pa.s
Cold water
Density: 995.67 kg/m3
Heat capacity: 4183.00 J/kg.K
Thermal cond: 0.6155 W/m.K
Viscosity: 0.0008007 Pa.s
CALCULATIONS FOR SHELL AND TUBE (Counter-Current)
Fixed Hot water flow rate at 10 LPM
TEST 1 TEST 2 TEST 3 TEST 4 TEST 5
Hot fluid (Tube): Water
Volumetric flowrate L/min 10.0 10.0 10.0 9.9 9.8
Mass flow kg/s 0.1647 0.1647 0.1647 0.1630 0.1614
Inlet temp oC 50.8 50.8 51.0 51.4 51.2
Outlet temp oC 48.6 47.9 47.6 47.4 47.1
Heat transfer rate J/s 1512.74 1994.06 2337.87 2722.93 2762.81
Pressure drop mmH2O 420.00 420.00 412.00 407.00 388.00
Cold fluid (Shell): Water
Volumetric flowrate L/min 2.0 3.8 5.6 7.3 9.1
Mass flow kg/s 0.0332 0.0631 0.0929 0.1211 0.1510
Inlet temp oC 31.2 30.4 30.3 30.2 30.2
Outlet temp oC 40.7 37.3 35.8 34.9 34.3
Heat transfer rate J/s 1318.88 1820.06 2137.98 2381.62 2589.87
Pressure drop mmH2O 35.50 116.30 238.40 400.20 over
Temp difference
Hot side inlet T, T1 oC 50.8 50.8 51 51.4 51.2
Hot side outlet T, T2 oC 48.6 47.9 47.6 47.4 47.1
Cold side inlet T, t1 oC 31.2 30.4 30.3 30.2 30.2
Cold side outlet T, t2 oC 40.7 37.3 35.8 34.9 34.3
T log mean, Tlm oC 13.42 15.41 16.23 16.85 16.00
Heat Loss W 193.86 174.01 199.89 341.31 172.95
Efficiency % 87.18 91.27 91.45 87.47 93.74
Overall heat transfer coeff
Total exchange area m2 0.15 0.15 0.15 0.15 0.15
Overall heat transfer coeff W/m2.K 752.97 864.22 962.41 1079.66 1153.50
Exchanger layout
Tube 1 1 1 1 1
Shell 1 1 1 1 1
Length of tubes m 0.5 0.5 0.5 0.5 0.5
Tube ID mm 7.75 7.75 7.75 7.75 7.75
Tube OD mm 9.53 9.53 9.53 9.53 9.53
Tube pitch mm 18 18 18 18 18
Tube surface area m2 0.0150 0.0150 0.0150 0.0150 0.0150
Number of tubes 10 10 10 10 10
Shell diameter mm 85 85 85 85 85
Baffle distance mm 50 50 50 50 50
Tube side
Cross section area m2 4.72E-05 4.72E-05 4.72E-05 4.72E-05 4.72E-05
Number of tubes 10 10 10 10 10
Total cross section area m2 4.72E-04 4.72E-04 4.72E-04 4.72E-04 4.72E-04
Mass velocity kg/m2.s 349.13 349.13 349.13 345.64 342.15
Linear velocity m/s 0.3533 0.3533 0.3533 0.3498 0.3462
Reynolds 4924.98 4924.98 4924.98 4875.73 4826.48
Prandtl 3.56 3.56 3.56 3.56 3.56
Type of flow turbulent turbulent turbulent turbulent turbulent
L/ID 64.52 64.52 64.52 64.52 64.52
Heat transfer factor, jh 3.90E-03 3.90E-03 3.90E-03 3.90E-03 3.90E-03
Tube coeff, hi W/m2.K 2426.16 2426.16 2426.16 2401.90 2377.64
Shell side
Cross flow area m2 2.00E-03 2.00E-03 2.00E-03 2.00E-03 2.00E-03
Mass velocity kg/m2.s 16.60 31.53 46.47 60.57 75.51
Linear velocity m/s 0.0167 0.0317 0.0467 0.0608 0.0758
Equivalent diameter mm 27.78 27.78 27.78 27.78 27.78
Reynolds 575.88 1094.17 1612.46 2101.96 2620.25
Prandtl 5.44 5.44 5.44 5.44 5.44
Type of flow laminar laminar laminar turbulent turbulent
Baffle cut % 20 20 20 20 20
Heat transfer factor, jh 2.30E-02 1.80E-02 1.60E-02 1.40E-02 1.20E-02
Shell coeff, hs W/m2.K 513.18 763.08 999.59 1140.16 1218.25
Pressure drops across heat exchanger
Tube-side friction factor, jf 5.80E-03 5.80E-03 5.80E-03 5.80E-03 5.80E-03
Shell-side friction factor, jf 9.80E-02 8.60E-02 7.50E-02 7.20E-02 7.00E-02
Tube-side pressure drop, Dptube (Pa) 338.8 338.8 338.8 332.1 325.4
Tube-side pressure drop, DPtube (mmH2O) 33.4 33.4 33.4 32.8 32.1
Shell-side pressure drop, DPshell (Pa) 3.3 10.5 19.9 32.5 49.1
Shell-side pressure drop, DPshell (mmH2O) 0.3 1.0 2.0 3.2 4.8
Experiment 1.B: Co-Current Shell & Tube Heat Exchanger
TYPICAL CHEMICAL DATA
Hot water
Density: 988.18 kg/m3
Heat capacity: 4175.00 J/kg.K
Thermal cond: 0.6436 W/m.K
Viscosity: 0.0005494 Pa.s
Cold water
Density: 995.67 kg/m3
Heat capacity: 4183.00 J/kg.K
Thermal cond: 0.6155 W/m.K
Viscosity: 0.0008007 Pa.s
CALCULATIONS FOR SHELL AND TUBE (Co-Current)
Fixed Hot water flow rate at 10 LPM
TEST 1 TEST 2 TEST 3 TEST 4 TEST 5
Hot fluid (Tube): Water
Volumetric flowrate L/min 9.9 9.9 9.9 9.9 10.1
Mass flow kg/s 0.1630 0.1630 0.1630 0.1630 0.1663
Inlet temp oC 51.1 51.1 51.3 51.2 51.2
Outlet temp oC 49.0 48.2 47.8 47.2 46.9
Heat transfer rate J/s 1429.54 1974.12 2382.56 2722.93 2986.28
Pressure drop mmH2O 405.00 405.00 408.00 406.00 402.00
Cold fluid (Shell): Water
Volumetric flowrate L/min 2.0 3.8 5.6 7.5 9.2
Mass flow kg/s 0.0332 0.0631 0.0929 0.1245 0.1527
Inlet temp oC 31.6 30.8 30.4 30.3 30.4
Outlet temp oC 40.2 36.8 35.4 34.5 34.1
Heat transfer rate J/s 1193.93 1582.66 1943.61 2186.57 2362.88
Pressure drop mmH2O 35.40 117.00 233.00 411.30 over
Temp difference
Hot side inlet T, T1 oC 51.1 51.1 51.3 51.2 51.2
Hot side outlet T, T2 oC 49 48.2 47.8 47.2 46.9
Cold side inlet T, t1 oC 31.6 30.8 30.4 30.3 30.4
Cold side outlet T, t2 oC 40.2 36.8 35.4 34.5 34.1
T log mean, Tlm oC 13.45 15.42 16.28 16.46 16.48
Heat Loss W 235.60 391.47 438.95 536.36 623.40
Efficiency % 83.52 80.17 81.58 80.30 79.12
Overall heat transfer coeff
Total exchange area m2 0.15 0.15 0.15 0.15 0.15
Overall heat transfer coeff W/m2.K 710.11 854.97 977.52 1105.01 1210.67
Exchanger layout
Tube 1 1 1 1 1
Shell 1 1 1 1 1
Length of tubes m 0.5 0.5 0.5 0.5 0.5
Tube ID mm 7.75 7.75 7.75 7.75 7.75
Tube OD mm 9.53 9.53 9.53 9.53 9.53
Tube pitch mm 18 18 18 18 18
Tube surface area m2 0.0150 0.0150 0.0150 0.0150 0.0150
Number of tubes 10 10 10 10 10
Shell diameter mm 85 85 85 85 85
Baffle distance mm 50 50 50 50 50
Tube side
Cross section area m2 4.72E-05 4.72E-05 4.72E-05 4.72E-05 4.72E-05
Number of tubes 10 10 10 10 10
Total cross section area m2 4.72E-04 4.72E-04 4.72E-04 4.72E-04 4.72E-04
Mass velocity kg/m2.s 345.64 345.64 345.64 345.64 352.62
Linear velocity m/s 0.3498 0.3498 0.3498 0.3498 0.3568
Reynolds 4875.73 4875.73 4875.73 4875.73 4974.23
Prandtl 3.56 3.56 3.56 3.56 3.56
Type of flow turbulent turbulent turbulent turbulent turbulent
L/ID 64.52 64.52 64.52 64.52 64.52
Heat transfer factor, jh 3.90E-03 3.90E-03 3.90E-03 3.90E-03 3.90E-03
Tube coeff, hi W/m2.K 2401.90 2401.90 2401.90 2401.90 2450.43
Shell side
Cross flow area m2 2.00E-03 2.00E-03 2.00E-03 2.00E-03 2.00E-03
Mass velocity kg/m2.s 16.60 31.53 46.47 62.23 76.34
Linear velocity m/s 0.0167 0.0317 0.0467 0.0625 0.0767
Equivalent diameter mm 27.78 27.78 27.78 27.78 27.78
Reynolds 575.88 1094.17 1612.46 2159.55 2649.04
Prandtl 5.44 5.44 5.44 5.44 5.44
Type of flow laminar laminar laminar turbulent turbulent
Baffle cut % 20 20 20 20 20
Heat transfer factor, jh 2.40E-02 1.80E-02 1.60E-02 1.50E-02 1.30E-02
Shell coeff, hs W/m2.K 535.49 763.08 999.59 1255.06 1334.27
Pressure drops across heat exchanger
Tube-side friction factor, jf 5.80E-03 5.80E-03 5.80E-03 5.80E-03 5.80E-03
Shell-side friction factor, jf 9.20E-02 8.20E-02 7.50E-02 7.20E-02 7.00E-02
Tube-side pressure drop, Dptube (Pa) 332.1 332.1 332.1 332.1 345.6
Tube-side pressure drop, DPtube (mmH2O) 32.8 32.8 32.8 32.8 34.1
Shell-side pressure drop, DPshell (Pa) 3.1 10.0 19.9 34.3 50.1
Shell-side pressure drop, DPshell (mmH2O) 0.3 1.0 2.0 3.4 4.9
Experiment 2.A: Counter-Current Spiral Heat Exchanger
TYPICAL CHEMICAL DATA
Hot water
Density: 988.18 kg/m3
Heat capacity: 4175.00 J/kg.K
Thermal cond: 0.6436 W/m.K
Viscosity: 0.0005494 Pa.s
Cold water
Density: 995.67 kg/m3
Heat capacity: 4183.00 J/kg.K
Thermal cond: 0.6155 W/m.K
Viscosity: 0.0008007 Pa.s
CALCULATIONS FOR SPIRAL HEAT EXCHANGER (Counter-Current)
Fixed Hot water flow rate at 5 LPM
TEST 1 TEST 2 TEST 3 TEST 4 TEST 5
Hot fluid (Tube): Water
Volumetric flowrate L/min 4.90 4.90 4.90 4.90
Mass flow kg/s 8.07E-02 8.07E-02 8.07E-02 8.07E-02
Inlet temp oC 51.00 51.00 51.10 51.10
Outlet temp oC 47.90 47.60 47.50 47.10
Heat transfer rate J/s 1044.48 1145.56 1212.94 1347.71
Cold fluid (Shell): Water
Volumetric flowrate L/min 2.10 3.00 3.70 4.70
Mass flow kg/s 0.03 0.05 0.06 0.08
Inlet temp oC 31.10 30.90 30.60 30.60
Outlet temp oC 37.60 35.80 34.90 34.20
heat transfer rate J/s 947.51 1020.40 1104.39 1174.50
Temp difference
Hot side inlet T, T1 oC 51.00 51.00 51.10 51.10
Hot side outlet T, T2 oC 47.90 47.60 47.50 47.10
Cold side inlet T, t1 oC 31.10 30.90 30.60 30.60
Cold side outlet T, t2 oC 37.60 35.80 34.90 34.20
T log mean, Tlm oC 15.04 15.94 16.55 16.70
Heat Loss W 96.97 125.16 108.55 173.21
Efficiency % 90.72 89.07 91.05 87.15
Overall heat transfer coeff
Total exchange area m2 0.15 0.15 0.15 0.15
Overall heat transfer coeff W/m2.K 420.96 427.68 445.84 469.83
Exchanger layout
Coil 1.00 1.00 1.00 1.00
Shell 1.00 1.00 1.00 1.00
Length of tubes m 5.00 5.00 5.00 5.00
Tube ID mm 7.05 7.05 7.05 7.05
Tube OD mm 9.53 9.53 9.53 9.53
Coil surface area m2 0.15 0.15 0.15 0.15
Shell diameter mm 85.00 85.00 85.00 85.00
Coil ID mm 34.00 34.00 34.00 34.00
Coil OD mm 44.00 44.00 44.00 44.00
Tube side
Cross section area m2 3.90E-05 3.90E-05 3.90E-05 3.90E-05
Mass velocity kg/m2.s 2067.34 2067.34 2067.34 2067.34
Linear velocity m/s 2.09 2.09 2.09 2.09
Reynolds 26528.53 26528.53 26528.53 26528.53
Prandtl 3.56 3.56 3.56 3.56
Type of flow turbulent turbulent turbulent turbulent
Tube coeff, hi W/m2.K 11047.45 11047.45 11047.45 11047.45
Shell side
Cross flow area m2 0.01 0.01 0.01 0.01
Mass velocity kg/m2.s 6.88 9.83 12.13 15.41
Linear velocity m/s 0.00691 0.00988 0.01218 0.01548
Equivalent diameter mm 39.54 39.54 39.54 39.54
Reynolds 339.97 485.67 598.99 760.88
Prandtl 5.44 5.44 5.44 5.44
Type of flow laminar laminar laminar laminar
Nusselt Number 4.26 5.67 6.71 8.12
Stanton Number 0.00230 0.00215 0.00206 0.00196
Heat transfer factor, jh 0.00717 0.00668 0.00640 0.00610
Shell coeff, hs W/m2.K 66.35 88.26 104.39 126.40
Experiment 2.B: Co-Current Spiral Heat Exchanger
TYPICAL CHEMICAL DATA
Hot water
Density: 988.18 kg/m3
Heat capacity: 4175.00 J/kg.K
Thermal cond: 0.6436 W/m.K
Viscosity: 0.0005494 Pa.s
Cold water
Density: 995.67 kg/m3
Heat capacity: 4183.00 J/kg.K
Thermal cond: 0.6155 W/m.K
Viscosity: 0.0008007 Pa.s
CALCULATIONS FOR SPIRAL HEAT EXCHANGER (Co-Current)
Fixed Hot water flow rate at 5 LPM
TEST 1 TEST 2 TEST 3 TEST 4 TEST 5
Hot fluid (Tube): Water
Volumetric flowrate L/min 5.00 5.00 5.00 5.00
Mass flow kg/s 0.08 0.08 0.08 0.08
Inlet temp oC 51.10 51.10 51.00 51.10
Outlet temp oC 48.20 47.50 47.00 46.90
Heat transfer rate J/s 997.03 1237.70 1375.22 1443.98
Cold fluid (Shell): Water
Volumetric flowrate L/min 2.00 2.80 3.80 4.80
Mass flow kg/s 0.03 0.05 0.06 0.08
Inlet temp oC 32.30 31.90 31.80 31.60
Outlet temp oC 38.00 36.70 36.00 35.10
heat transfer rate J/s 791.33 932.93 1107.86 1166.17
Temp difference
Hot side inlet T, T1 oC 51.10 51.10 51.00 51.10
Hot side outlet T, T2 oC 48.20 47.50 47.00 46.90
Cold side inlet T, t1 oC 32.30 31.90 31.80 31.60
Cold side outlet T, t2 oC 38.00 36.70 36.00 35.10
T log mean, Tlm oC 14.06 14.60 14.72 15.33
Heat Loss W 205.70 304.76 267.36 277.81
Efficiency % 79.37 75.38 80.56 80.76
Overall heat transfer coeff
Total exchange area m2 0.15 0.15 0.15 0.15
Overall heat transfer coeff W/m2.K 375.85 426.88 502.72 508.20
Exchanger layout
Coil 1.00 1.00 1.00 1.00
Shell 1.00 1.00 1.00 1.00
Length of tubes m 5.00 5.00 5.00 5.00
Tube ID mm 7.05 7.05 7.05 7.05
Tube OD mm 9.53 9.53 9.53 9.53
Coil surface area m2 0.15 0.15 0.15 0.15
Shell diameter mm 85.00 85.00 85.00 85.00
Coil ID mm 34.00 34.00 34.00 34.00
Coil OD mm 44.00 44.00 44.00 44.00
Tube side
Cross section area m2 0.00 0.00 0.00 0.00
Mass velocity kg/m2.s 2109.53 2109.53 2109.53 2109.53
Linear velocity m/s 2.13 2.13 2.13 2.13
Reynolds 27069.93 27069.93 27069.93 27069.93
Prandtl 3.56 3.56 3.56 3.56
Type of flow turbulent turbulent turbulent turbulent
Tube coeff, hi W/m2.K 11227.45 11227.45 11227.45 11227.45
Shell side
Cross flow area m2 0.01 0.01 0.01 0.01
Mass velocity kg/m2.s 6.56 9.18 12.46 15.74
Linear velocity m/s 0.01 0.01 0.01 0.02
Equivalent diameter mm 39.54 39.54 39.54 39.54
Reynolds 323.78 453.29 615.18 777.07
Prandtl 5.44 5.44 5.44 5.44
Type of flow laminar laminar laminar laminar
Nusselt Number 4.10 5.37 6.85 8.26
Stanton Number 0.00 0.00 0.00 0.00
Heat transfer factor, jh 0.01 0.01 0.01 0.01
Shell coeff, hs W/m2.K 63.81 83.52 106.64 128.55
Experiment 3.A: Counter-Current Concentric Heat Exchanger
TYPICAL CHEMICAL DATA
Hot water
Density: 988.18 kg/m3
Heat capacity: 4175.00 J/kg.K
Thermal cond: 0.6436 W/m.K
Viscosity: 0.0005494 Pa.s
Cold water
Density: 995.67 kg/m3
Heat capacity: 4183.00 J/kg.K
Thermal cond: 0.6155 W/m.K
Viscosity: 0.0008007 Pa.s
CALCULATIONS FOR CONCENTRIC HEAT EXCHANGER (Counter-Current)
Fixed Hot water flow rate at 10 LPM
TEST 1 TEST 2 TEST 3 TEST 4 TEST 5
Hot fluid (Tube): Water
Volumetric flowrate L/min 9.70 9.60 9.60 9.70 9.70
Mass flow kg/s 0.15976 0.15811 0.15811 0.15976 0.15976
Inlet temp oC 51.10 51.10 51.10 51.10 51.10
Outlet temp oC 50.00 49.90 49.80 49.70 49.70
Heat transfer rate J/s 733.68 792.13 858.14 933.77 933.77
Cold fluid (Shell): Water
Volumetric flowrate L/min 2.00 3.70 5.40 7.20 8.90
Mass flow kg/s 0.03319 0.06140 0.08961 0.11948 0.14769
Inlet temp oC 32.70 31.90 31.70 31.40 31.40
Outlet temp oC 35.30 33.70 33.20 32.70 32.60
Heat transfer rate J/s 360.96 462.30 562.26 649.72 741.35
Temp difference
Hot side inlet T, T1 oC 51.10 51.10 51.10 51.10 51.10
Hot side outlet T, T2 oC 50.00 49.90 49.80 49.70 49.70
Cold side inlet T, t1 oC 32.70 31.90 31.70 31.40 31.40
Cold side outlet T, t2 oC 35.30 33.70 33.20 32.70 32.60
T log mean, Tlm oC 16.54 17.70 18.00 18.35 18.40
Heat Loss W 372.72 329.82 295.88 284.05 192.42
Efficiency % 49.20 58.36 65.52 69.58 79.39
Overall heat transfer coeff
Total exchange area m2 0.05 0.05 0.05 0.05 0.05
Overall heat transfer coeff W/m2.K 845.55 853.09 908.70 969.93 967.30
Exchanger layout
Tube 1.00 1.00 1.00 1.00 1.00
Shell 1.00 1.00 1.00 1.00 1.00
Length of tubes m 0.50 0.50 0.50 0.50 0.50
Tube ID mm 26.64 26.64 26.64 26.64 26.64
Tube OD mm 33.40 33.40 33.40 33.40 33.40
Tube surface area m2 0.05 0.05 0.05 0.05 0.05
Shell diameter mm 85.00 85.00 85.00 85.00 85.00
Tube side
Cross section area m2 0.000557 0.000557 0.000557 0.000557 0.000557
Mass velocity kg/m2.s 286.61 283.66 283.66 286.61 286.61
Linear velocity m/s 0.29004 0.28705 0.28705 0.29004 0.29004
Reynolds 13897.73 13754.45 13754.45 13897.73 13897.73
Prandtl 3.56 3.56 3.56 3.56 3.56
Nuselt number 72.15 71.55 71.55 72.15 72.15
Type of flow turbulent turbulent turbulent turbulent turbulent
Stanton Number 0.00146 0.00146 0.00146 0.00146 0.00146
Heat transfer factor, jh 0.00341 0.00342 0.00342 0.00341 0.00341
Tube coeff, hi W/m2.K 1743.02 1728.63 1728.63 1743.02 1743.02
Shell side
Cross flow area m2 0.0048 0.0048 0.0048 0.0048 0.0048
Mass velocity kg/m2.s 6.917 12.796 18.675 24.900 30.780
Linear velocity m/s 0.00695 0.01285 0.01876 0.02501 0.03091
Equivalent diameter mm 51.60 51.60 51.60 51.60 51.60
Reynolds 445.74 824.62 1203.50 1604.67 1983.55
Prandtl 5.44 5.44 5.44 5.44 5.44
Type of flow laminar laminar laminar laminar laminar
Nuselt number 5.29 8.66 11.72 14.75 17.48
Stanton Number 0.00218 0.00193 0.00179 0.00169 0.00162
Heat transfer factor, jh 0.00679 0.00600 0.00557 0.00526 0.00504
Shell coeff, hs W/m2.K 63.15 103.30 139.78 175.96 208.47
Experiment 3.B: Co-Current Concentric Heat Exchanger
TYPICAL CHEMICAL DATA
Hot water
Density: 988.18 kg/m3
Heat capacity: 4175.00 J/kg.K
Thermal cond: 0.6436 W/m.K
Viscosity: 0.0005494 Pa.s
Cold water
Density: 995.67 kg/m3
Heat capacity: 4183.00 J/kg.K
Thermal cond: 0.6155 W/m.K
Viscosity: 0.0008007 Pa.s
CALCULATIONS FOR CONCENTRIC HEAT EXCHANGER (Co-Current)
Fixed Hot water flow rate at 10 LPM
TEST 1 TEST 2 TEST 3 TEST 4 TEST 5
Hot fluid (Tube): Water
Volumetric flowrate L/min 9.4 9.4 9.6 9.8 9.7
Mass flow kg/s 0.1548 0.1548 0.1581 0.1614 0.1598
Inlet temp oC 51.1 51.1 51.1 51.1 51.0
Outlet temp oC 49.7 49.7 49.7 49.7 49.6
Heat transfer rate J/s 904.89 904.89 924.15 943.40 933.77
Cold fluid (Shell): Water
Volumetric flowrate L/min 2.0 3.7 5.5 7.2 8.9
Mass flow kg/s 0.0332 0.0614 0.0913 0.1195 0.1477
Inlet temp oC 32.6 31.8 31.7 31.6 31.6
Outlet temp oC 35.7 33.9 33.0 32.7 32.5
Heat transfer rate J/s 430.37 539.35 496.32 549.77 556.01
Temp difference
Hot side inlet T, T1 oC 51.1 51.1 51.1 51.1 51
Hot side outlet T, T2 oC 49.7 49.7 49.7 49.7 49.6
Cold side inlet T, t1 oC 32.6 31.8 31.7 31.6 31.6
Cold side outlet T, t2 oC 35.7 33.9 33 32.7 32.5
T log mean, Tlm oC 16.15 17.49 18.02 18.22 18.23
Heat Loss W 474.52 365.54 427.83 393.63 377.76
Efficiency % 47.56 59.60 53.71 58.27 59.54
Overall heat transfer coeff
Total exchange area m2 0.05 0.05 0.05 0.05 0.05
Overall heat transfer coeff W/m2.K 1068.26 986.05 977.71 986.84 976.53
Exchanger layout
Tube 1 1 1 1 1
Shell 1 1 1 1 1
Length of tubes m 0.5 0.5 0.5 0.5 0.5
Tube ID mm 26.64 26.64 26.64 26.64 26.64
Tube OD mm 33.4 33.4 33.4 33.4 33.4
Tube surface area m2 0.0525 0.0525 0.0525 0.0525 0.0525
Shell diameter mm 85 85 85 85 85
Tube side
Cross section area m2 5.57E-04 5.57E-04 5.57E-04 5.57E-04 5.57E-04
Mass velocity kg/m2.s 277.75 277.75 283.66 289.57 286.61
Linear velocity m/s 0.2811 0.2811 0.2871 0.2930 0.2900
Reynolds 13467.90 13467.90 13754.45 14041.00 13897.73
Prandtl 3.56 3.56 3.56 3.56 3.56
Nuselt number 70.36 70.36 71.55 72.74 72.15
Type of flow turbulent turbulent turbulent turbulent turbulent
Stanton Number 1.47E-03 1.47E-03 1.46E-03 1.45E-03 1.46E-03
Heat transfer factor, jh 3.43E-03 3.43E-03 3.42E-03 3.41E-03 3.41E-03
Tube coeff, hi W/m2.K 1699.75 1699.75 1728.63 1757.38 1743.02
Shell side
Cross flow area m2 4.80E-03 4.80E-03 4.80E-03 4.80E-03 4.80E-03
Mass velocity kg/m2.s 6.92 12.80 19.02 24.90 30.78
Linear velocity m/s 0.0069 0.0129 0.0191 0.0250 0.0309
Equivalent diameter mm 51.60 51.60 51.60 51.60 51.60
Reynolds 445.74 824.62 1225.79 1604.67 1983.55
Prandtl 5.44 5.44 5.44 5.44 5.44
Type of flow laminar laminar laminar laminar laminar
Nuselt number 5.29 8.66 11.89 14.75 17.48
Stanton Number 2.18E-03 1.93E-03 1.78E-03 1.69E-03 1.62E-03
Heat transfer factor, jh 6.79E-03 6.00E-03 5.55E-03 5.26E-03 5.04E-03
Shell coeff, hs W/m2.K 63.15 103.30 141.85 175.96 208.47
Experiment 4.A: Counter-Current Plate Heat Exchanger
TYPICAL CHEMICAL DATA
Hot water
Density: 988.18 kg/m3
Heat capacity: 4175.00 J/kg.K
Thermal cond: 0.6436 W/m.K
Viscosity: 0.0005494 Pa.s
Cold water
Density: 995.67 kg/m3
Heat capacity: 4183.00 J/kg.K
Thermal cond: 0.6155 W/m.K
Viscosity: 0.0008007 Pa.s
CALCULATIONS FOR COUNTER-CURRENT FLOW PLATE HEAT EXCHANGER
Fixed Hot water flow rate at 7.5 LPM TEST 1 TEST 2 TEST 3 TEST 4 TEST 5
Hot fluid: Water
Actual volume flow L/min 7.18 7.18 7.18 7.18 7.18
Mass flow kg/s 0.11825 0.11825 0.11825 0.11825 0.11825
Inlet temp (calibrated temp) oC 50.5 50.5 50.5 50.5 50.5
Outlet temp (calibrated temp) oC 45.9 43.5 41.6 40.4 39.7
Heat transfer rate J/s 2298.2 3487.2 4379.0 4973.5 5320.3
Cold fluid: Water Actual volume flow L/min 2.10 3.74 5.48 7.39 8.82
Mass flow kg/s 0.03485 0.06206 0.09094 0.12263 0.14636
Inlet temp (calibrated temp) oC 32.9 32.5 32.5 32.5 32.5
Outlet temp (calibrated temp) oC 48.2 45.9 43.8 42.0 41.1
Heat transfer rate J/s 2235.6 3458.0 4261.5 4867.7 5254.1
Temp difference
Hot side inlet T, T1 oC 50.52 50.52 50.52 50.52 50.52
Hot side outlet T, T2 oC 45.86 43.45 41.65 40.44 39.74
Cold side inlet T, t1 oC 32.85 32.55 32.55 32.55 32.55
Cold side outlet T, t2 oC 48.19 45.87 43.75 42.04 41.13
T log mean, Tlm oC 6.21 7.34 7.87 8.18 8.24
Heat loss W 62.6 29.3 117.5 105.9 66.3
Efficiency % 97.3 99.2 97.3 97.9 98.8
Overall heat transfer coeff
Total plate area m2 0.092 0.092 0.092 0.092 0.092
Overall heat transfer coeff W/m2.K 4024.32 5167.48 6046.14 6607.78 7019.42
Exchanger layout
Plate channel mm 1.29 1.29 1.29 1.29 1.29
No of plates 6 6 6 6 6
Plate width mm 71 71 71 71 71
Plate Length mm 308 308 308 308 308
Plate area m2 0.018 0.018 0.018 0.018 0.018
Cross sectional area m2 0.00009 0.00009 0.00009 0.00009 0.00009
Plate film coefficient (hot)
Total cross section m2 2.75E-04 2.75E-04 2.75E-04 2.75E-04 2.75E-04
Equivalent diameter, de m 2.58E-03 2.58E-03 2.58E-03 2.58E-03 2.58E-03
Mass velocity kg/m2.s 430.37 430.37 430.37 430.37 430.37
Linear velocity m/s 0.4355 0.4355 0.4355 0.4355 0.4355
Reynolds 2021.02 2021.02 2021.02 2021.02 2021.02
Prandtl 3.56 3.56 3.56 3.56 3.56
Hot film coeff W/m2.K 15183.17 15183.17 15183.17 15183.17 15183.17
Plate film coefficient (cold)
Total cross section m2 2.75E-04 2.75E-04 2.75E-04 2.75E-04 2.75E-04
Equivalent diameter, de m 2.58E-03 2.58E-03 2.58E-03 2.58E-03 2.58E-03
Mass velocity kg/m2.s 126.8277 225.8741 330.9599 446.3128 532.6764
Linear velocity, Gp m/s 0.1274 0.2269 0.3324 0.4483 0.5350
Reynolds 408.66 727.81 1066.41 1438.10 1716.38
Prandtl 5.44 5.44 5.44 5.44 5.44
Cold film coeff W/m2.K 6084.99 8854.91 11350.76 13785.94 15465.79
Experiment 4.B: Co-Current Plate Heat Exchanger
TYPICAL CHEMICAL DATA
Hot water
Density: 988.18 kg/m3
Heat capacity: 4175.00 J/kg.K
Thermal cond: 0.6436 W/m.K
Viscosity: 0.0005494 Pa.s
Cold water
Density: 995.67 kg/m3
Heat capacity: 4183.00 J/kg.K
Thermal cond: 0.6155 W/m.K
Viscosity: 0.0008007 Pa.s
CALCULATIONS FOR CO-CURRENT FLOW PLATE HEAT EXCHANGER
Fixed Hot water flow rate at 7.5 LPM TEST 1 TEST 2 TEST 3 TEST 4 TEST 5
Hot fluid: Water
Actual volume flow L/min 6.66 6.66 6.66 6.66 6.66
Mass flow kg/s 0.11 0.11 0.11 0.11 0.11
Inlet temp (calibrated temp) oC 50.5 50.5 50.5 50.5 50.5
Outlet temp (calibrated temp) oC 46.6 44.7 42.8 41.9 41.4
Heat transfer rate J/s 1792.86 2683.23 3510.42 3924.01 4153.79
Cold fluid: Water Actual volume flow L/min 2.07 3.68 5.74 7.50 8.88
Mass flow kg/s 0.03 0.06 0.10 0.12 0.15
Inlet temp (calibrated temp) oC 33.7 33.4 33.1 32.9 32.9
Outlet temp (calibrated temp) oC 46.0 43.8 41.4 40.3 39.5
Heat transfer rate J/s 1764.58 2673.72 3327.30 3875.40 4091.55
Temp difference
Hot side inlet T, T1 oC 50.52 50.52 50.52 50.52 50.52
Hot side outlet T, T2 oC 46.60 44.66 42.85 41.95 41.44
Cold side inlet T, t1 oC 33.67 33.37 33.07 32.86 32.86
Cold side outlet T, t2 oC 45.95 43.83 41.42 40.31 39.50
T log mean, Tlm oC 4.97 5.37 6.41 6.74 7.12
Heat loss W 28.28 9.51 183.12 48.62 62.24
Efficiency % 98.42 99.65 94.78 98.76 98.50
Overall heat transfer coeff
Total plate area m2 0.092 0.092 0.092 0.092 0.092
Overall heat transfer coeff W/m2.K 3918.48 5429.50 5954.82 6331.88 6342.69
Exchanger layout
Plate channel mm 1.29 1.29 1.29 1.29 1.29
No of plates 6 6 6 6 6
Plate width mm 71 71 71 71 71
Plate Length mm 308 308 308 308 308
Plate area m2 0.018 0.018 0.018 0.018 0.018
Cross sectional area m2 0.00009 0.00009 0.00009 0.00009 0.00009
Plate film coefficient (hot)
Total cross section m2 2.75E-04 2.75E-04 2.75E-04 2.75E-04 2.75E-04
Equivalent diameter, de m 2.58E-03 2.58E-03 2.58E-03 2.58E-03 2.58E-03
Mass velocity kg/m2.s 399.20 399.20 399.20 399.20 399.20
Linear velocity m/s 0.40 0.40 0.40 0.40 0.40
Reynolds 1874.65 1874.65 1874.65 1874.65 1874.65
Prandtl 3.56 3.56 3.56 3.56 3.56
Hot film coeff W/m2.K 14459.05 14459.05 14459.05 14459.05 14459.05
Plate film coefficient (cold)
Total cross section m2 2.75E-04 2.75E-04 2.75E-04 2.75E-04 2.75E-04
Equivalent diameter, de m 2.58E-03 2.58E-03 2.58E-03 2.58E-03 2.58E-03
Mass velocity kg/m2.s 125.02 222.25 346.66 452.96 536.30
Linear velocity, Gp m/s 0.13 0.22 0.35 0.45 0.54
Reynolds 402.82 716.13 1117.01 1459.51 1728.06
Prandtl 5.44 5.44 5.44 5.44 5.44
Cold film coeff W/m2.K 6028.35 8762.31 11697.97 13918.98 15534.10
Sample Calculation for Shell and Tube Heat Exchanger TYPICAL CHEMICAL DATA Hot water Density: 988.18 kg/m3 Heat capacity: 4175.00 J/kg.K Thermal cond: 0.6436 W/m.K Viscosity: 0.0005494 Pa.s Cold water Density: 995.67 kg/m3 Heat capacity: 4183.00 J/kg.K Thermal cond: 0.6155 W/m.K Viscosity: 0.0008007 Pa.s
Cold Water Flowrate = 2.0 LPM
COUNTER-CURRENT FLOW (Hot water inlet at 50'C)
Hot fluid (Tube-side): Water
Volume flow L/min 10.0
Inlet temp oC 50.8
Outlet temp oC 48.6
Cold fluid(Shell-Side): Water
Volume flow L/min 2.0
Inlet temp oC 31.2
Outlet temp oC 40.7
SHELL AND TUBE HEAT EXCHANGER LAYOUT
Tube 1
Shell 1
Length of tubes m 0.5
Tube ID mm 7.75
Tube OD mm 9.53
Tube pitch mm 18
Tube surface area m2 0.015
Number of tubes 10
Shell diameter mm 85
Baffle length mm 50
Baffle Cut % 20
1. Calculation of Heat transfer and heat Lost:
The Heat Transfer rate of both hot and cold water are both calculated using the heat balance
equation.
W
CCkg
J
m
kg
sL
mL
TCmQ phhot
74.1512
)6.488.50(.
417518.98860
min1
1000
1
min0.10
(W) Hot Water,for RateTransfer Heat
3
3
W
CCkg
J
m
kg
sL
mL
TCmQ pccold
88.1318
)2.317.40(.
418367.99560
min1
1000
1
min0.2
(W) Water,Coldfor ReteTransfer Heat
3
3
%18.87%10074.1512
88.1318%100/Efficiency
86.19388.131874.1512 LostHeat
hotcold
coldhot
WQQRate
2. Calculation of Log Mean Temperature Difference:
C
inTcoutThoutTcinThToutThoutTcinThTlm
42.13
2.316.48
7.408.50ln
)2.316.48()7.408.50(
,,/,,ln/inc,,,,
3. Calculation of the tube and shell heat transfer coefficients by Kern’s method: For 1-shell pass; 1-tube pass, Tm = Tlm
Heat transfer coefficient at Tube side:
Cross Flow Area, A = 4
πd 2i
= 4
00775.03.142 2
= 0.0000472 m2
Total cross Flow Area, At = 0.0000472 x number of tubes
= 0.0000472 x 10
= 0.000472 m2
Mass velocity, Gt = t
t
A
m
= 0.000472
0.1647
= 349.13 kg/m2.s
Linear Velocity, ut = ρ
Gt
= 988.18
349.13
= 0.3533 m/s
Renolds No, Re =
et dG
= 1000
1
0.0005494
75.713.349
= 4924.8 (Turbulent Flow)
Prandtl No, Pr = kCp
= 0.6436
41750005494.0
= 3.56
Tube side heat transfer factor, jh = 0.0039 (From Fig. C.2, Appendix C)
Tube Side Coefficient, hi = i
h
d
kj 33.0PrRe
= 0.00775
6436.056.398.49240.0039 0.33
= 2426.16 Wm-2K
Heat transfer coefficient at shell side:
Cross Flow Area, As = [(Tube pitch-Tube OD) x (Shell Diameter) x (Baffle distance)]/Tube pitch
= 0.002 m2
Mass velocity, Gs = s
s
A
W
= 0.002
0.0332
= 16.60 kg/m2.s
Linear Velocity, us = ρ
Gs
= 995.67
16.60
= 0.0167m/s
Equivalent Diameter, de = 2o
2t
o
0.917dpd1.1
= 22 )0.917(9.53819.531.1
= 27.78 mm
Reynolds Number, Re =
es dG
= 1000
1
0.0008007
78.2760.16
= 575.88 (Laminar Flow)
Prandtl No, Pr = kCp
= 0.6155
00.18340008007.0
= 5.44
Shell side heat transfer factor, jh = 0.023 (From Fig. C.4, Appendix C)
Shell Side Coefficient, hi = de
kjh 33.0PrRe
= 0.02053
6155.044.516.605023.0 0.33
= 513.18 W/m2.K
Overall heat transfer coefficient:
Total exchange area, A = Number of tube x x Tube OD x Length of Tubes
= 10 x x (9.53/1000) x 0.5
= 0.15 m2
Overall heat transfer coefficient, U = lm
hot
TA
Q
= 752.97 W/m2.K
4. Calculation of Pressure Drop across Tube and Shell
5.2)/(82
2
mwif
tpt dLj
uNP
= 5.2)00775.0/5.0(0058.082
3533.018.988 2
= 338.8 Pa
14.02
2)/)(/(8 w
sBesfs
ulLdDjP
Pa
Ps
3.3
0.12
)0167.0)(67.995(
05.0
5.0
02778.0
085.0)098.0)(8( 14.0
2
The pressure drop measured experimentally is the combination of pressure drop across the heat exchanger construction and fittings. Therefore, the measured pressure drops will be much greater than the actual pressure drops across the heat exchanger. 5. Temperature Profile for counter-current Shell and Tube Heat Exchanger
Sample Calculation for Spiral Heat Exchanger TYPICAL CHEMICAL DATA Hot water Density: 988.18 kg/m3 Heat capacity: 4175.00 J/kg.K Thermal cond: 0.6436 W/m.K Viscosity: 0.0005494 Pa.s Cold water Density: 995.67 kg/m3 Heat capacity: 4183.00 J/kg.K Thermal cond: 0.6155 W/m.K Viscosity: 0.0008007 Pa.s
Cold Water Flowrate = 2.0 LPM
COUNTER-CURRENT FLOW (Hot water inlet at 50'C)
Hot fluid (Tube-side): Water
Volume flow L/min 4.90
Inlet temp oC 51.0
Outlet temp oC 47.9
Cold fluid(Shell-Side): Water
Volume flow L/min 2.10
Inlet temp oC 31.1
Outlet temp oC 37.6
SPIRAL HEAT EXCHANGER LAYOUT Coil 1
Shell 1
Length of tubes m 5
Tube ID mm 7.05
Tube OD mm 9.53
Coil surface area m2 0.15
Shell diameter mm 85
Coil ID mm 34
Coil OD mm 44
1. Calculation of Heat transfer and heat Lost:
The Heat Transfer rate of both hot and cold water are both calculated using the heat balance equation.
W
CCkg
Jm
kg
sL
mL
TCmQ phhot
48.1044
)9.470.51(.
4175
18.98860
min1
1000
1
min90.4
(W) Hot Water,for RateTransfer Heat
3
3
W
CCkg
Jm
kg
sL
mL
TCmQ pccold
51.947
)1.316.37(.
4183
67.99560
min1
1000
1
min1.2
(W) Water,Coldfor ReteTransfer Heat
3
3
%72.90%10048.1044
51.947%100/Efficiency
97.9651.94748.1044 LostHeat
hotcold
coldhot
WQQRate
2. Calculation of Log Mean Temperature Difference:
C
inTcoutThoutTcinThToutThoutTcinThTlm
04.15
1.319.47
6.370.51ln
)1.319.47()6.370.51(
,,/,,ln/inc,,,,
3. Calculation of the tube and shell heat transfer coefficients by Kern’s method: Assuming, Tm = Tlm
Heat transfer coefficient at Tube side:
Cross Flow Area, At = 4
πd 2i
= 4
00705.03.142 2
= 0.000039 m2
Mass velocity, Gt = t
t
A
m
= 0.000039
0.0807
= 2067.34 kg/m2.s
Linear Velocity, ut = ρ
Gt
= 988.18
2067.34
= 2.09 m/s
Renolds No, Re =
et dG
= 1000
1
0.0005494
05.734.2067
= 26528.53 (Turbulent Flow)
Prandtl No, Pr = kCp
= 0.6436
41750005494.0
= 3.56
Tube Side Coefficient, hi = ed
k33.08.0 PrRe023.0
= 0.00705
6436.056.353.26528023.0 0.338.0
= 11047.45Wm-2K
Heat transfer coefficient at shell side:
Cross Flow Area, As = 21
22
234
DDD
= 222 033.0044.0085.04
= 0.00506 m2
Mass velocity, Gs = s
s
A
W
= 0.005060.0332
= 6.88kg/m2.s
Linear Velocity, us = ρ
Gs
= 995.67
6.88
= 0.00691m/s
Equivalent Diameter, de =
321
21
22
23
ddd
ddd
=
344485344485 222
= 39.54 mm
Reynolds Number, Re =
es dG
= 1000
1
0.0008007
54.3988.6
= 339.97 (Laminar Flow)
Prandtl Number, Pr = kCp
= 0.6155
00.18340008007.0
= 5.44
Nuselt Number, Nu = 33.08.0 PrRe023.0
= 33.08.0 44.597.339023.0
= 4.26
Stanton Number, St = PrRe
Nu
= 44.597.339
27.4
= 0.00230
Heat transfer factor, jh = 67.0PrSt
= 67.044.500230.0
= 00717.0
Shell Side Coefficient, hs = de
kjh 33.0PrRe
= 0.03954
6155.044.597.33900717.0 0.33
= 66.35W/m2.K
Overall heat transfer coefficient:
Total exchange area, A = x (0.00953/1000) x 5.0
= 0.15 m2
Overall heat transfer coefficient, U = lm
hot
TA
Q
= 420.96 W/m2.K
4. Temperature Profile for counter-current Spiral Heat Exchanger
Sample Calculation for Concentric Heat Exchanger TYPICAL CHEMICAL DATA Hot water Density: 988.18 kg/m3 Heat capacity: 4175.00 J/kg.K Thermal cond: 0.6436 W/m.K Viscosity: 0.0005494 Pa.s Cold water Density: 995.67 kg/m3 Heat capacity: 4183.00 J/kg.K Thermal cond: 0.6155 W/m.K Viscosity: 0.0008007 Pa.s
Cold Water Flowrate = 2.0 LPM
COUNTER-CURRENT FLOW (Hot water inlet at 50'C)
Hot fluid (Tube-side): Water
Volume flow L/min 9.70
Inlet temp oC 51.1
Outlet temp oC 50.0
Cold fluid(Shell-Side): Water
Volume flow L/min 2.0
Inlet temp oC 32.7
Outlet temp oC 35.3
SHELL AND TUBE HEAT EXCHANGER LAYOUT Tube 1
Shell 1
Length of tubes m 0.5
Tube ID mm 26.64
Tube OD mm 33.4
Tube surface area m2 0.0525
Shell diameter mm 85
1. Calculation of Heat transfer and heat Lost:
The Heat Transfer rate of both hot and cold water are both calculated using the heat balance equation.
W
CCkg
Jm
kg
sL
mL
TCmQ phhot
68.733
)0.501.51(.
4175
18.98860
min1
1000
1
min70.9
(W) Hot Water,for RateTransfer Heat
3
3
W
CCkg
Jm
kg
sL
mL
TCmQ pccold
96.360
)7.323.35(.
4183
67.99560
min1
1000
1
min0.2
(W) Water,Coldfor ReteTransfer Heat
3
3
%20.49%10068.733
96.360%100/Efficiency
72.37296.36068.733 LostHeat
hotcold
coldhot
WQQRate
2. Calculation of Log Mean Temperature Difference:
C
inTcoutThoutTcinThToutThoutTcinThTlm
54.16
7.320.50
3.351.51ln
)7.320.50()3.351.51(
,,/,,ln/inc,,,,
3. Calculation of the tube and shell heat transfer coefficients by Kern’s method: Assuming, Tm = Tlm
Heat transfer coefficient at Tube side:
Cross Flow Area, At = 4
πd 2i
= 4
02664.03.142 2
= 0.000557 m2
Mass velocity, Gt = t
t
A
m
= 0.000557
0.1597
= 286.61 kg/m2.s
Linear Velocity, ut = ρ
Gt
= 988.18
286.61
= 0.29004 m/s
Renolds Number, Re =
et dG
= 1000
1
0.0005494
64.2661.286
= 13897.73 (Turbulent Flow)
Prandtl No, Pr = kCp
= 0.6436
41750005494.0
= 3.56
Nuselt Number, Nu = 33.08.0 PrRe023.0
= 33.08.0 56.373.13897023.0
= 72.15
Stanton Number, St = PrRe
Nu
= 56.373.13897
15.72
= 0.00146
Heat transfer factor, jh = 67.0PrSt
= 67.056.300146.0
= 0.00341
Tube Side Coefficient, hi = id
k33.08.0 PrRe023.0
= 0.02664
6436.056.373.13897023.0 0.338.0
= 1743.02 Wm-2K
Heat transfer coefficient at shell side:
Cross Flow Area, As = 22
4 os dD
= 0.0048 m2
Mass velocity, Gs = s
s
A
W
= 0.0048
0.0332
= 6.917 kg/m2.s
Linear Velocity, us = ρ
Gs
= 995.67
6.917
= 0.00695 m/s
Equivalent Diameter, de = 12 dd
= 4.330.85
= 51.6 mm
Reynolds Number, Re =
es dG
= 1000
1
0.0008007
6.51917.6
= 445.74 (Laminar Flow)
Prandtl No, Pr = kCp
= 0.6155
00.18340008007.0
= 5.44
Nuselt Number, Nu = 33.08.0 PrRe023.0
= 33.08.0 44.574.445023.0
= 5.29
Stanton Number, St = PrRe
Nu
= 44.574.445
29.5
= 0.00218
Heat transfer factor, jh = 67.0PrSt
= 67.044.500218.0
= 0.00679
Shell Side Coefficient, hs = de
kjh 33.0PrRe
= 0.0516
6155.029.574.44500679.0 0.33
= 63.15 W/m2.K
Overall heat transfer coefficient:
Total exchange area, A = x Tube OD x Length of Tubes
= x (26.64/1000) x 0.5
= 0.05 m2
Overall heat transfer coefficient, U = lm
hot
TA
Q
= 845.55 W/m2.K
4. Temperature Profile for counter-current Shell and Tube Heat Exchanger
Sample Calculation for Plate Heat Exchanger TYPICAL CHEMICAL DATA Hot water Density: 988.18 kg/m3 Heat capacity: 4175.00 J/kg.K Thermal cond: 0.6436 W/m.K Viscosity: 0.0005494 Pa.s Cold water Density: 995.67 kg/m3 Heat capacity: 4183.00 J/kg.K Thermal cond: 0.6155 W/m.K Viscosity: 0.0008007 Pa.s
Cold Water Flowrate = 2.0 LPM
COUNTER-CURRENT FLOW (Hot water inlet at 50'C)
Hot fluid (Tube-side): Water
Volume flow L/min 7.18
Inlet temp oC 50.5
Outlet temp oC 45.9
Cold fluid(Shell-Side): Water
Volume flow L/min 2.10
Inlet temp oC 32.9
Outlet temp oC 48.2
PLATE HEAT EXCHANGER LAYOUT
Total cross section area m2 0.000275
Plate width mm 71
Plate length mm 308
Plate channel mm 1.29
No. of plate 6
1. Calculation of Heat Lost and Efficiency:
The heat transfer rate of both hot and cold water is both calculated using the heat balance equation.
W
CCkg
Jm
kg
s
m
TCmQ phhot
2.2298
)9.455.50(.
4175
18.98860
min1
min1000
18.7
(W) Hot Water,for ratefer heat trans
3
3
W
CCkg
Jm
kg
s
m
TCmQ pccold
6.2235
)9.322.48(.
4183
67.99560
min1
min1000
10.2
(W) Water,Coldfor ratefer Heat trans
3
3
%3.97%1002.2298
6.2235%100/Efficiency
6.626.22352.2298 =LostPower
coldhot
coldhot
WQQ
2. Calculation of Log Mean Temperature Difference:
C
inTcoutThoutTcinThToutThoutTcinThTlm
21.6
9.329.45
2.485.50ln
)9.329.45()2.485.50(
,,/,,ln/inc,,,,
3. Calculation of the hot and cold plate heat transfer coefficients: Heat Transfer Coefficient at Hot Plate
Mass Velocity = AreaSectionCrossTotal
RateFlowMass
= 2m0
s0.11825kg/000275.
= 430.37 kg/m2.s
Linear Velocity = Density
VelocityMass
= 3
2
mkg/9skg/m
18.88
37.430
= 0.4355 m/s Equivalent Diameter, de = depth2 = 2 x 0.00129 = 0.00258 m
Reynolds No = viscocity
deVelocity Mass
= Pa.s0.00054940.00258ms30.37kg/m2 4
= 2021.02
Prandtl No = tyConductiviThermal
ViscocityCapacityHeat
= W/m.s0.6436
Pa.s0.0005494CJ/kg.00.1754
= 3.56
Plate Film Coefficient at Hot Side, hpH = de
kPrRe0.26 0.40.65
= 0.00258
0.64363 0.26 0.40.65 56.02.2021 x
= 15183.17 W/m2.K Heat Transfer Coefficient at Cold Plate
Mass Velocity = AreaSectionCrossTotal
RateFlowMass
= 2m0
kg/s
000275.
03485.0
= 126.8277 kg/m2.s
Linear Velocity = Density
VelocityMass
= 3
2
mkg/995.67
skg/m126.8277
= 0.1274 m/s
Reynolds No = viscocity
deVelocity Mass
= Pa.s0.00080071
m0skg/m126.8277 2 00258.
= 408.66
Prandtl No = tyConductiviThermal
ViscocityCapacityHeat
= W/m.s6155.0
Pa.s0008007.0CJ/kg.00.1834
= 5.44
Plate Film Coefficient at Cold Side, hpC = de
kPrRe0.26 0.40.65
= 0.00258
.50.26 0.40.65 6155044.66.408
= 6084.99W/m2.K
Temperature Sensor Calibration Table
Actual Temperature Sensor Temperature
T1 T2 T3 T4
30 30.0 29.7 30.0 29.2
35 35.0 34.8 35.0 34.0
40 40.0 39.7 40.0 39.7
45 44.8 44.6 45.0 44.6
50 49.6 49.5 49.7 49.4
55 54.5 54.4 54.8 54.5
60 59.7 59.6 60.0 59.5
65 64.0 64.4 64.8 64.4
70 69.6 69.5 69.8 69.4
75 74.5 74.4 74.8 74.4
80 79.6 79.4 79.8 79.2
85 84.2 84.4 84.6 84.2
90 88.8 89.5 89.3 89.0
slope 0.9920 0.9924 0.9965 0.9898
correcting factor for the calibrated sensor temperature
1.0081 1.0077 1.0035 1.0103
Note: The temperature recorded from the indicator need to multiply the correcting factor to get the accurate temperature reading.