A United Technologies company - Carrier UK · Temperature Rise C 1850 1900 1950 2000 2050 Year....

TOSHIBA

A United Technologies companyA United Technologies company

Andrew Keogh

Refrigerant

Matters

TOSHIBA

Refrigerant Matters

Agenda

Phaseouts

Environmental Issues

Total Environmental Warming Impact

Refrigerant Chemistry

Natural Refrigerants

HFC’s

Chiller Technology

TOSHIBA

Hamilton Sundstrand

Carrier Pratt & Whitney

Sikorsky

Otis

TOSHIBA

Toshiba Carrier UK Ltd

OfficesOffices

Leatherhead (HQ)

Plymouth (Warehouse)

Orpington

Heathrow

Warrington

Birmingham

Glasgow

Belfast

HeadcountHeadcount

Plymouth 40

Carrier Service 110

Sales and Admin 100

TOTAL 250

TOSHIBA

• Light Commercial focus

• High brand awareness

• National account focus

• VRF segment growing

Toshiba

TOSHIBA

• Commercial focus

• Target specified work

• Prestige installations

• Brand known as commercial

Carrier

TOSHIBA

Thomas MidgleyInventor Of Chlorocarbon Refrigerants

TOSHIBA

EC Regulation 2037/2000

Ban CFC’s for servicing A/C from July 2001

Bring forward the HCFC phase out dates

50 % cut 2001

75 % cut 2004

90 % cut 2010

Tighten HCFC end-use controls

Ban in new Air Conditioning >100kW from 1/1/2001

Ban in new Air Conditioning <100 kW from 1/7/2002

Ban for new heat pumps from 2004

No virgin HCFC’s for service from 2010

TOSHIBA

‘F’ Gas Directive

Take all practical steps to minimise leakage

Mandatory inspections for leakage

> 3 kg – inspect annually

> 30 kg – inspect bi-annually

> 300 kg – inspect quarterly

Mandatory leak detection on equipment > 300 kg

Mandatory record of gas usage for plant > 3kg

Improved recovery of refrigerants

Mandatory training

TOSHIBA

Environmental Issues

Ozone Depletion

Greenhouse Effect

What RefrigerantWhat Refrigerant

Today ?Today ?

TOSHIBA

The Greenhouse Effect

Global warming

Increase in the greenhouse effect as the result of

human industrial activity

Accelerating production of natural gases

– CO2, CH4

Production of new gases

– NO2, CFC & HCFC

TOSHIBA

Relative Contributions to the

Greenhouse Effect

0

10

20

30

40

50

60

%

CO2 CFC's CH4 HCFC's NO2 H2O

Compound

TOSHIBA

Growth in Carbon Dioxide Levels

250

270

290

310

330

350

370

PPM

1720 1760 1800 1840 1880 1920 1960 2000

Year

TOSHIBA

Predicted Development of Global Warming

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2T

em

pe

ratu

re R

ise

C

1850 1900 1950 2000 2050

Year

TOSHIBA

TEWI

INDIRECT + DIRECT

TOSHIBA

Calculating TEWI for a Chiller

Chiller life (years) 20

Refrigerant Charge (kg) 60

Refrigerant Type R22

Loss rate (% / yr) 3

ITH (20 -100 - 500 years) 100

GWP 1700

Direct emission of CO2 (kg ) 61,200

TOSHIBA

Calculating TEWI for a Chiller

Nominal cooling capacity (kW) 300

Annual capacity load factor (%) 50

COP (kW/kW) 4

Chiller total power input (kWh) 3,000,000

Cooler PD (kPa) 50

Condenser PD (kPa) 50

Annual pumps load factor (%) 100

Cooler pump total power input (kWh) 47,000

Cond. pump total power input (kWh) 47,000

Country UK

Regional Conversion factor (kg CO2/kW) 0.5

Indirect Global Warming Effect 1,547,000

TOSHIBA

Relative Contributions to Global Warming

5%

95%DIRECT

INDIRECT

TOSHIBA

Refrigerant GWP Capacity Cycle COP

R22 1700 1.00 1.00

R134a 1300 0.64 1.01

R407c 1610 1.02 1.05

R404a 3750 1.10 0.91

R410a 1890 1.38 0.95

Alternative Refrigerants

Summary of Properties

TOSHIBA

Build on the concept of TEWI

Total TEWI is dependent upon:

Equipment performance

System design

System control

System maintenance

TOSHIBA

System Evaluation

0

50000

00000

50000

00000

50000

00000

0.21

0.22

0.23

0.24

0.25

0.26

0.27

0.28

0.29

0.30

0.31

0.32

0.33

0 10 20 30 40 50 60 70 80 90 100

Cooli

ng kW

h Per

Year

Chiller System ikW/kW

Building Load (%)

Cooling kWh Chiller System ikW/kW

TOSHIBA

Understanding Refrigerant Chemistry

A Guide To What’s Left After ThePhaseouts

TOSHIBA

Periodic Table of the Elements

Refrigerant components

Tend to Form Solids

Toxic or Unstable (Reactive)

Unstable, Manmade or

Radioactive & Rare

Does Not React

H

Na Mg

K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Ar

Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe

Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Ti Pb Bl Po At Rn

Fr Ra As

H He

B C N O F Ne

Al Si P S Cl Ar

Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu

Th Pg U Np Pu Am Cm Bk Ct Es Fm Md No Lw

Li Be

TOSHIBA

CL

H F

Flammable

Compromises in the Properties ofRefrigerants

TOSHIBA

CL

Toxic

Flammable

H F


TOSHIBA

CL

Flammable

H F

R-22

R-12

R-11Toxic

R-123

R-134a


TOSHIBA


R11

R12

CFC

R22

R123

HCFC

R32

R134a

R125

R143a

HFC

R717

R290

H2O

CO2

Natural

Pure Fluids

Refrigerants

TOSHIBA

Long used, well established refrigerant

Zero ODP and no direct GWP

High efficiency

Very corrosive to copper and copper alloys

Toxic, fatal at concentrations of 0.5% v/v

Flammable at concentrations of 15 to 28% v/v

Code restrictions on use

See latest edition of EN 378

Alternative Refrigerants - Ammonia

TOSHIBA

Zero ODP and no direct GWP

Capacity slightly lower but efficiency is equal to R22

No material problems

Mineral oils can be used as a lubricant

Highly flammable / explosive

1 kg of hydrocarbon is equivalent to 1 Kg of TNT

Code restrictions on use

See latest edition of EN 378

Alternative Refrigerants - Hydrocarbons

TOSHIBA

ARE YOU LIABLE FOR REFRIGERANT CHOICE ?

“I would say that if you are bringing into yourbuilding, a substance for which there is analternative that is less dangerous, you’re goingto be scrutinized if there is a problem...”

Helen ZukinManager,Environmental Litigation GroupLos Angeles, CA

TOSHIBA

Comparison of TEWI

0

20

40

60

80

100

120

140

160T

EW

I

R404a R407c R22 R410a R134a NH3

TOSHIBA

Safe

Environmentally Acceptable

Good Thermophysical Properties


Water

TOSHIBA


Water

For a cooling capacity of 100TR (350 kW)

Mass flow of water is 0.140 kg/s

The volume flow of water vapour at 0.007 barA

is about 25.6 m3/s

Conventional vapour compression equipment

capable of handling such a volume is both large

and expensive

TOSHIBA

TOSHIBA

Environmental Considerations

Carbon dioxide emissions

Vapour Compression

350 kW @ COP = 4

Energy Input = 87.5 kWe

CO2 equivalence = 0.414

CO2 Emission = 36.23 kg

Absorption

350 kW @ COP = 1.1

Energy Input = 318 kWg

CO2 equivalence = 0.194

CO2 emission = 61.7 kg

TOSHIBA

Absorption Chiller with CHP

Electrical Load

Heating Load

Engine GeneratorCooling

Tower

Absorption

ChillerCooling Load

HX

TOSHIBA

Absorption and CHP

Very low electrical demand

Low thermal efficiency

Large plant

Water cooled with very high

specific heat of rejection

Operation down to 20 deg C

without tower bypass

control

Low noise & vibration levels

typical 80dBA

TOSHIBA

Absorption and CHP - Economic Considerations

Climate change levy (April 2001)

Surcharge on electricity of 0.43 pence per kWh

Surcharge on gas of 0.15 pence per kWh

Exemptions for CHP provided

Quality Index > 100 for exisiting schemes

Quality Index > 110 for new schemes

QI = 200* e + 130* t

Systems qualify for ECA’s

TOSHIBA

Air Cycle

TOSHIBA

Air Cycle

Motor

Compressor Expander

Heat Exchanger

Air In Air Out

TOSHIBA

TOSHIBA

Air Cycle - Performance

1.542.041.542.071.542.04COP Overall

1.181.471.181.491.181.47COP Heating

0.360.570.360.570.360.57COP Cooling

56 kW140 kW56 kW139 kW56 kW140 kWInput Power kW

66 kW206 kW66 kW208 kW66 kW206 kWHeating kW

20 kW80 kW20 kW80 kW20 kW80 kWCooling kW

-3 C-3 C15 C15 C28 C28 CAmbient

TOSHIBA

Air Cycle - Advantages

Simultaneous cooling and heating

80 deg C + hot water temperatures

COP’s independent of ambient

Robust equipment

Easy re-charging

Low air temperatures possible

TOSHIBA

Air Cycle – Disadvantages

Requires ‘balanced’ load

Poor COP’s

A/C chiller 3.0 (cooling) at 28 C ambient (cf 0.5)

With heat recovery COP rises to 4

Noise

Cost

Nobody makes a commercial version

TOSHIBA

Carbon Dioxide

TOSHIBA

Carbon Dioxide – R744

Used in early part of 20th Century

Low cost / Non-flammable / Non-toxic

Competition

Ammonia

Sulphur dioxide

Methyl Chloride

CFC’s and HCFC’s were superior in all respects

Low efficiencies and high pressures

TOSHIBA

Properties

2301313268394210214H vapourisation

1284658100854913411331Density liquid

1.251.361.761.201.161.27Cp Ratio

1.414.532.192.411.291.15Cp liquid

17106810711P/T Sensitivity

4712362288292164296Pressure kPa

73133319710196Critical Temp

R410aR717R744R290R134aR22Refrigerant

TOSHIBA

Trans-critical Cycle

200

250

300

350

400

-500 -400 -300 -200 -100 0.00 100

Enthalpy, h, [kJ/kg]

TOSHIBA

Basic Cycles

.31.16.55.300.290.25Inlet Quality

1681102123279147163Refrigeration

Effect

3.924.953.153.684.704.03Pressure ratio

4.394.752.534.544.614.66Cooling COP

R410aR717R744R290R134aR22Refrigerant

TOSHIBA

R744 - Development

To meet current levels of efficiency

New heat exchanger designs

Improved heat transfer technology

Efficient expander

New, high efficiency compressor

Potential as a secondary heat transfer fluid

TOSHIBA


R11

R12

CFC

R22

R123

HCFC

R32

R134a

R125

R143a

HFC

R717

R290

H2O

CO2

Natural

Pure Fluids

R407c

R404a

Zeotropes

R502

R507

R410a

Azeotropes

Mixtures

Refrigerants

TOSHIBA

Properties of Alternative Refrigerants

Op

era

tin

g P

res

su

re

0 250 500 750 1000 1250 1500 1750

Volumetric Capacity

0

2

4

6

8

10

12

R12

R134a

R22

R407c

R502

R125

R507R410a

R32

R404a

TOSHIBA

Numbering system

R134a tetrafluoro-ethane C2H2F4

134+90 = 224

2 carbon 2 hydrogen 4 fluorine

C

FL

FL

H

Add 90 to the number

C H

FL

FL

TOSHIBA

Widely used :

Automobile Air Conditioning

Centrifugal Chillers

Pharmaceutical Applications

As component in nearly all HFC blends


R134a

TOSHIBA

Widely used :





No application restrictions

Other alternatives limited by low critical temperature


R134a

TOSHIBA

Widely used :







Low GWP and TEWI


R134a

TOSHIBA

Widely used :







Low GWP and TEWI

Simplicity

‘Pure’ Refrigerant

No fractionation - No Service Complications

No Glide - No Danger of Freezing Cooler Tubes


R134a

TOSHIBA


Op

era

tin

g P

res

su

re

0 250 500 750 1000 1250 1500 1750

Volumetric Capacity

0

2

4

6

8

10

12

R12

R134a

R22

R407c

R502

R125

R507R410a

R32

R404a

TOSHIBA

TOSHIBA

Screw Compressor Design for R134a

Rotors optimised for R134a

Slide valve capacity control

TOSHIBA

TOSHIBA

R22R407

High

Pressure

&

Capacity

Low

Pressure

&

Capacity

R125

H

FL

FL

FL

FL

C CFLFL FL

H

C

R32

H

R134a

FL H

FL

FL FL

C C

H

TOSHIBA

R22’s closest functional equivalent;

Was initially regarded as retro-fittable with only

minor system modifications


R407c

TOSHIBA


was initially regarded as retro-fittable with only

minor modifications

Overall system capacity and efficiency loss

compared to R22.


R407c

TOSHIBA

McQuay water-cooled screw chiller (BRE)

Carried out with the help of ICI

COP reduced by 9%

Capacity reduced by 8 %

Results attributed to poor heat transfer coefficients

Site Test Results

TOSHIBA

Heat Transfer Characteristics

Evaporator

0

2000

4000

6000

8000

10000

0 0.2 0.4 0.6 0.8 1

Quality x

HT

C (

W/m

2 C

)

R22

R407c

TOSHIBA

Mixture Boiling Characteristic

Light component

Heavy component

Nucleation

site

Vapour bubble

TOSHIBA


was initially regarded as retrofittable with only

minor modifications


compared to R22.

The tendency to fractionate can compromise

performance and complicate maintenance.


R407c

TOSHIBA


was initially regarded as retrofittable with only

minor modifications


compared to R22.

The tendency to fractionate can compromise

performance and complicate maintenance.

5.5 Deg C Glide


R407c

TOSHIBA

Glide

Enthalpy

Pre

ss

ure

Enthalpy

Pre

ss

ure

PsatTsat

Tdew

Tbub

Glide

Psat

TOSHIBA

Te

mp

era

ture

Length

R22

Water

Te

mp

era

ture

Length

R407c

Water

Te

mp

era

ture

Length

R407c

Water

Mixed Flow Mixed Flow

TOSHIBA

+

=

Aquasnap Chiller

TOSHIBA


Op

era

tin

g P

res

su

re

0 250 500 750 1000 1250 1500 1750

Volumetric Capacity

0

2

4

6

8

10

12

R12

R134a

R22

R407c

R502

R125

R507R410a

R32

R404a

TOSHIBA

R410a

High

Pressure

&

Capacity

Low

Pressure

&

Capacity

R125

H

FL

FL

FL

FL

C CFLFL FL

H

C

R32

H

TOSHIBA


R410a

Inferior Thermodynamics (low critical temperature)

Higher Pressures

Higher vapour density

Higher capacity

Superior heat transfer and low pressure drops

Good isentropic compressor efficiency

Mixture that behaves like a pure fluid

TOSHIBA

Evaporative Heat Transfer Performance

4

4.5

5

5.5

6

6.5

7

7.5

8

0.2 0.3 0.4 0.5 0.6 0.7 0.8

Quality

He

at

Tra

nsfe

rfi

R22

R410A

R134a

R407C

Liquid Vapour

TOSHIBA

Ambient Air Temperature

Leaving Chilled Water Temperature

Discharge Pressure Drop

Condensing Temp

Suction Pressure Drop

Evaporating temp

Compression

R407C

Temperature

R410A System Advantages

TOSHIBA

Ambient Air Temperature

Leaving Chilled Water Temperature

Discharge Pressure Drop

Condensing Temp

Suction Pressure Drop

Evaporating temp

Compression

R407C

Temperature

R410A System Advantages

R410A

Reduced

Lift

Every 1 deg C

reduction in

temperature lift

equates to ~ 3%

improvement in COP

TOSHIBA

190 - 760 kW

190 - 500 kW

TOSHIBA

Summary

HFC Alternatives

R407c

Performance depends on HX technology

Fractionation makes service complicated

Losing ground to R410A

R134a

Cheap, simple and widely used

No application limitations

Requires increased compressor displacement

R410a

Promises higher efficiencies than R407c

Standard for most splits / VRF

Application range extended into medium chillers

A United Technologies company - Carrier UK · Temperature Rise C 1850 1900 1950 2000 2050 Year....

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Transcript of A United Technologies company - Carrier UK · Temperature Rise C 1850 1900 1950 2000 2050 Year....