Refrigerant Selection Considerations

Transcription

1 Refrigerant Selection Considerations Daniel Dettmers Industrial Refrigeration Consortium University of Wisconsin (866)

2 What is a Refrigerant? Refrigerant - the vital working fluid in refrigeration, air-conditioning, and heat pumping systems. - absorbs heat from one area, such as an air-conditioned space, and rejects it into another, such as outdoors, usually through evaporation and condensation process, respectively. -ASHRAE Fundamentals Chpt. 16

3 Refrigerant Selection Criteria Safety, risk & regulation Environmental impacts Likelihood of future availability Refrigerant properties Toxicity & flammability Thermodynamic & transport Other Economics Operating efficiency Capital costs (refrigerant & equipment) Staff capabilities

4 Composition of Fluorocarbons CFC-12 HCFC-22 HFC-32 Cl Cl H Cl H H C C C F F F F F F C hloro F luoro C arbons H ydro C hloro F luoro C arbons H ydro F luoro C arbons

5 HCFC Phaseout Schedule (US) % Reduction in National Consumption 100% 65% HCFC-22 HCFC-142b Production Freeze Ban in New Equipment HCFC-22 HCFC-142b Production Ban 35% HCFC-141b Production Ban All other HCFCs Production Freeze All other HCFCs Ban in New Equipment All other HCFCs Production Ban 10% 0.5%

6 ODP and GWP ODP Ozone Depletion Potential Damage substance does to the ozone layer, relative to CFC-11 GWP Global Warming Potential Contribution of substance to the atmosphere s heat retention, relative to CO 2 or CFC Same as CFC-11 or CO 2 None

7 ODP and GWP from CFCs Global Warming Potential CFCs HCFCs HFCs Ozone Depletion Potentia ODP and GWP are relative to CFC-11 Source: World Meteorological Organization

8 ODP and GWP of Non-CFCs 123 Ozone Pepletion Potential Global Warming Potential b b 134a a CFCs HCFCs HFCs ODP and GWP are relative to CFC-11 Source: World Meteorological Organization 152a 32

9 Safety & ODP/GWP of Refrigerants Chemical Lifetime ODP GWP Safety Refrigerant Formula Years (R11) (CO 2 ) Classification CFC-11 CCl 3 F A1 CFC-12 CCL 2 F A1 CFC-113 CCl 2 FCClF A1 CFC-114 CClFCClF A1 CFC-115 CClF 2 CF A1 HCFC-22 CHClF A1 HCFC-123 CF 3 CHCl B1 HCFC-124 CHClFCF A1 HCFC-141b CH 3 CCl 2 F HCFC-142b CH 3 CClF A2 HFC-32 CH 2 F A2 HFC-125 CHF 2 CF A1 HFC-134a CF 3 CH 2 F A1 HFC-143a CH 3 CF A2 HFC-152a CH 3 CHF A2 R-717 NH B2 R-718 H 2 O A1 HC-290 C 3 H A3

10 ASHRAE Standard Refrigerant Classification Safety Group Higher Flammability Lower Flammability No Flame Propagation Increasing Flammability A3 Propane, Butane A2 R-142b, R-152a A1 R-11, R-12, R-114 Lower Toxicity B3 B2 Ammonia B1 R-123, SO 2 Higher Toxicity Increasing Toxicity

11 Ideal Cycle Efficiency Comparison: Influence of Refrigerant Selection Refrigerant COP kw/ton HP/ton CFC CFC HCFC HFC-134a HCFC R R R-410A R-407C R-404A Source: ASHRAE Handbook of Fundamentals, 20 F evaporating and 105 F condensing temperatures

12 ASHRAE Numbering System From ASHRAE Standard 34 Single Component Fluorocarbons 000 Series - Methane Based Molecules 100 Series - Ethane Based 200 Series - Propane Based Fluids 300 Series - Butane Based Mixtures 400 Series - Zeotropic Blends (or Non-Azeotropic ) 500 Series - Azeotropes Others 600 Series - Miscellaneous Organic Compounds 700 Series - Inorganic Compounds

13 ASHRAE Numbering System From ASHRAE Standard 34 Single Component Fluorocarbons 000 Series - Methane Based Molecules 100 Series - Ethane Based 200 Series - Propane Based Fluids 300 Series - Butane Based Mixtures 400 Series - Zeotropic Blends (or Non-Azeotropic ) 500 Series - Azeotropes Others 600 Series - Miscellaneous Organic Compounds 700 Series - Inorganic Compounds

14 Refrigerant Mixtures Zeotropes (Blends or Simple Mixtures) R-400 series Tend to average properties Segregate (Easy to separate) Offer greatest flexibility Azeotropes R-500 series Behave like pure fluid Higher or lower B.P. than components Non segregating (Difficult to separate) Some Some Zeotropes are are very very close close to to Azeotropes

15 Evaporation Characteristics-Blends Boiling Point Boiling Point Dew GLIDE Bubble Point RANGE Point FLUID A Low-Boiler BLEND Non-Azeotropic (400 Series) FLUID B High-Boiler

16 Zeoptropic Refrigerant Behavior 250 R-407c Pressure [psia] ΔT~11 F Dew Point Bubble Point Temperature [F]

17 Phaseout Refrigerants Refrigerant CFC 11 CFC 12 CFC 502 CFC 13/R-503 HCFC 22 HCFC 123 Application Low Pressure Chillers Refrigerators, MVAC, Commercial Refrigeration Units Low Temperature Refrigeration Extremely Low Temperature Refrigeration Everywhere Low Pressure Chillers Alternative HCFC 123 HFC 134a R-404A (HFC) R-507A (HFC) HFC 23, R-508B, R NH 3, NH 3 -CO 2 Cascade R-717, R-410AR R-245ca* *Allowed by EPA, but I wouldn t use it quite yet.

18 Composition of R-502 Alternatives Large Glide

19 Long Term R-502 Alternatives Option 1 Option 2 Components 125 / 143a 125 / 143a / 134a Percentage 50% / 50% 44% / 52% / 4% ASHRAE # R-507A R-404A Trade names AZ-50 HP62 / Forane-404A Manufacturers Allied-Signal DuPont / Elf Atochem Glide 0.1 F 1.6 F Pressure * 359 psig 354 psig Capacity ** up 10% same COP ** up 0-5% up 5% * Condenser pressure at 130 F; R-502 is 321 psig ** Relative to R-502 Source: Dave Godwin, ARI AREP results

20 Composition of R-22 Alternatives Trade Name ASHRAE Number HFC-32 HFC-125 HFC-134a R-600 Several 134A 100% KLEA 407C, AC9000 AZ-20, Puron, Suva 9100 Large Glide 407C 23% 25% 52% 410A 50% 50% AC B 45% 55% Nu-22, ISCEON % 50% 3.4%

21 Long Term HCFC-22 Alternatives Option 1 Option 2 Option 3 Components 134a 32 / / 125 / 134a Percentage 100% 50% / 50% 23% / 25% / 52% ASHRAE # R-134a R-410A R-407C Trade names several AZ-20/PuronAC9000/KLEA66 Manufacturers several Allied-Signal DuPont/ICI Glide none 0.2 F 8-10 F Pressure * 200 psig 479 psig 310 psig Capacity ** down 30-40% up 40-50% up 10% COP ** within 5% down 5-13% down 5% * Condenser pressure at 130 F; HCFC-22 is 297 psig ** Relative to HCFC-22 Source: Dave Godwin, ARI AREP results

22 Other HCFC-22 Alternatives R-507A & R-404a System conversion possible with valve and lubricant change out Higher operating pressure & capacity R-417a (Nu-22) 125/134a/600 (46.6%/50%/3.4%) Drop-in, uses butane for MO miscibility Reported oil return problems, reduced low temp Copeland voids warranty if R-417a is used Many other refrigerants like it (R-422A, R-427A)

23 Alternatives to R-13/R-503 CFC 13 & R-503 (40.1/59.9 of R-23/R-13) Traditional refrigerants for extremely low temperature refrigeration (below -40 F) applications HFC 23 & R-508B (46/54 of R-23/R-116) GWP of 12,240 and 12,000 respectively Both have no ODP NH 3 -CO 2 Cascade Finding favor lately both in U.S. and Europe

24 CO 2 -NH 3 Cascade Refrigeration System Evaporative Condenser(s) High Temperature Evaporator(s) Low Temperature Evaporator(s) High Pressure Receiver Cascade Heat Exchanger T Low Temperature Recirculator 5 CO 2 Compressor(s) Ammonia Compressor(s)

25 CO 2 -NH 3 Cascade System No direct environmental impacts GWP, ODP High working pressures for CO 2 Low side 70 [psig] High side 300 [psig] Industrial scale systems currently in operation in both Europe and US Photos: Nestlé

26 CO 2 -NH 3 Cascade Efficiency Ammonia Efficiency [hp/ton] CO 2 /NH 3 Cascade Saturation Temperature [ F]

27 How to Protect Yourself 1. Check to make sure it is SNAP approved Check with compressor manufacturer Check warranties, oil issues, etc. 3. Check contractor s reference list Make sure they have successfully worked with this refrigerant in the past 4. Check cost Refrigerant, tax & operating cost