Low GWP R-410A Alternatives in Heat Pumps: Drop-in LCCP Evaluation

Transcription

1 Low GWP Alternatives in Heat Pumps: Drop-in LCCP Evaluation 214 Gang Li Yunho Hwang Center for Environmental Energy Engineering Department of Mechanical Engineering University of Maryland College Park, MD

2 Outline Introduction Experimental Apparatus Heat Pump Performance LCCP Assumptions LCCP Evaluation under Different US Cities LCCP Sensitivity Analysis Conclusions 2

3 Motivation 11 th IIR Gustav Lorentzen Conference on Natural Refrigerants Low GWP replacements needed in HVAC applications ODP= GWP: 2,88 ODP= Low GWP GWP: 675 GWP: 494 GWP: 272 AHRI supports AREP program LCCP analysis needed to evaluate the environmental impact (GHG emissions) Currently limited LCCP evaluation for low GWP refrigerants in HPs 3

4 4 11 th IIR Gustav Lorentzen Conference on Natural Refrigerants Refrigerant Properties Table 1: Comparison of Thermophysical Properties of Refrigerants Parameter Unit Temperature C Sat. Vapor Pressure kpa 2,653 1,81 2,73 1,17 2,49 1,16 2, Temperature Glide K Sat. Liquid Density kg/m , , ,74.3 Sat. Vapor Density kg/m Latent Heat kj/kg Sat. Liq. Spec. Heat kj/(kg-k) Sat. Vap. Spec. Heat kj/(kg-k) Sat. Liq. Therm. mw/(m-k) Conductivity Sat. Vap. Therm. mw/(m-k) Conductivity Sat. Liquid Viscosity μpa-s Sat. Vapor Viscosity μpa-s Vol. Cooling Capacity kj/m 3-8,84-9,39-7,656-6,22 GWP - 2,

5 Experimental Apparatus 5

6 Test Matrix 11 th IIR Gustav Lorentzen Conference on Natural Refrigerants Cooling Heating 6

7 LCCP Assumptions Refrigerant Charge amount Unit temp. switch: T_off: F T_on: 1 F Back up heat combustion data: Combustion efficiency 8% 7

8 Heat Pump Performance Capacity (kw) 8 6 COP Cooling A Cooling B Heating (high temp.) system test mode Heating (low temp.) Cooling A Cooling B Heating (high temp.) System test mode Heating (low temp.) 8

9 Heat Pump Performance- Charge Effects Cooling A 9 As the refrigerant charge amount is increased, the cooling capacity is increased and COP is increased first and then decreased

10 Heat Pump Performance- Charge Effects Cooling A 1 As the refrigerant charge amount is increased, the cooling capacity is increased and COP is increased first and then decreased

11 LCCP Evaluation under Different US Cities LCCP per lifetime (kg_co Cooling HP heating Backup heat R -32 From cold areas to hot areas: Cooling demand percentage is increased; No backup heat in hot areas; High emission reduction for and Minneapolis Chicago Philadelphia Richmond Los Angeles Houston Miami 11 Cold US c ities Hot

12 LCCP per lifetime (kg_co 2 11 th IIR Gustav Lorentzen Conference on Natural Refrigerants LCCP Evaluation under Different US Cities % -15.4% -25.7% From cold areas to hot areas: Direct emissions nearly remain constant; Indirect emissions are high in both cold and hot areas; Low emissions exist in mild area (LA) % % -17.4% Direct -27.1% % -27.1% Indirect % -2.6% -13.% -2.7% R % -14.1% -2.4% Minneapolis Chicago P hiladelphia Richmond Los Angeles Houston Miami 12 Cold US cities Hot

13 LCCP Evaluation under Different US Cities Direct Emissions: 14. Emissions - Annual Leakage Emissions - EOL Emissions - Service Emissions - Accidents 85.5 Indirect Emissions: 85.8% Emissions - Energy Consumption Emissions - Materials Emissions - Recycling Emissions - Charge High direct emissions Direct Emissions: 3.4% Emissions - Annual Leakage Emissions - EOL Emissions - Service Emissions - Accidents 96.3 Indirect Emissions: 96.6% Emissions - Energy Consumption Emissions - Materials Emissions - Recycling Emissions - Charge 9.74%.58% ,.19%.1%.16% %.46%.46%,.2.1%. Direct Emissions: 3.9% Emissions - Annual Leakage Emissions - EOL Emissions - Service Emissions - Accidents Indirect Emissions: 96.1% Emissions - Energy Consumption Emissions - Materials Emissions - Recycling Emissions - Charge Direct Emissions: 2.4% Emissions - Annual Leakage Emissions - EOL Emissions - Service Emissions - Accidents Indirect Emissions: 97.6% Emissions - Energy Consumption Emissions - Materials Emissions - Recycling Emissions - Charge % 13.16%.54%.54%,..1% %.3.3,.26%.1%.6%

14 LCCP Sensitivity Analysis Effect of COP Improvements Cooling HP heating Backup heat Direct Indirect (COP,%) 5 (COP,%) 1 (COP,%) 15 (COP,%) (COP,%) (COP,%) 5 (COP,%) 1 (COP,%) 15 (COP,%) (COP,%) 5 (COP,%) 1 (COP,%) 15 (COP,%) (COP,%) 5 (COP,%) 1 (COP,%) 15 (COP,%) 1 (COP,%) 5 14 COP Improvement It has high influence on emissions Direct emissions remain constant (COP,%) 15 (COP,%) (COP,%) 5 (COP,%) 1 (COP,%) 15 LCCP per lifetime (kg_co2 LCCP per lifetime (kg_co % % -24.6% % -27.1% -3.4% % -3.9% -7.4% -1.6% (COP,%) (COP,%) (COP,%) 5 (COP,%) 1 (COP,%) 15 (COP,%) (COP,%) 5 (COP,%) 1 (COP,%) 15 COP Improvement

15 LCCP per lifetime (kg_ 11 th IIR Gustav Lorentzen Conference on Natural Refrigerants LCCP Sensitivity Analysis Effect of Annual Leakage Rates Cooling HP heating Backup heat LCCP per lifetime (kg_ Annual leakage -3.9% 3.9% 7.8% Direct % Indirect -16.9% -16.1% -27.6% -27.1% -26.6% % 9% 7% 9% 9% 7% Annual Leakage Rate 7% 9% It has high influence on emissions Indirect emissions remain constant Direct emissions varied (due to annual leakage) 7% 9% 7% 9% 7% 9% Annual Leakage Rate 9% 7%

16 LCCP per lifetime (kg_ 11 th IIR Gustav Lorentzen Conference on Natural Refrigerants LCCP Sensitivity Analysis Effect of Refrigerant EOLs Cooling HP heating Backup heat LCCP per lifetime (kg_ Ref EOL %.7% -6.6% -6.4% -6. Direct -6.1% -18.% -17.8% Indirect -17.7% -17.6% % -27.% 16 1% 1 1% 1 1% 1 Refrigerant EOL 1% 1 It has small influence on emissions Indirect emissions remain constant (All these conclusions can be analyzed with emission distributions in slide page 11 ) 1% 1 1% 1 Refrigerant EOL 1% 1 1% 1

17 LCCP per lifetime (kg_ 11 th IIR Gustav Lorentzen Conference on Natural Refrigerants LCCP Sensitivity Analysis Effect of Service Leakage Rates Cooling HP heating Backup heat LCCP per lifetime (kg_ Service leakage % Direct -5.6% -17.9% -17.7% Indirect % -27.% -26.8% 17 8% 11% 8% 11% 8% 11% Service Leakage Rate 8% 11% It has small influence on emissions Indirect emissions remain constant 8% 11% 8% 11% 8% 11% Service Leakage Rate 8% 11%

18 LCCP per lifetime (kg_ 11 th IIR Gustav Lorentzen Conference on Natural Refrigerants LCCP Sensitivity Analysis Effect of Accident Leakage Rates Cooling HP heating Backup heat LCCP per lifetime (kg_ Accident leakage 2.% 3.9% 5.9% -5.8% % Direct % Indirect -16.6% % % 18 % 1% % 1% % 1% Accident Leakage Rate % 1% It has high influence on emissions Indirect emissions remain constant (All these conclusions can be analyzed with emission distributions in slide page 11 ) % 1% % 1% % 1% Accident Leakage Rate % 1%

19 LCCP per lifetime (kg_ 11 th IIR Gustav Lorentzen Conference on Natural Refrigerants LCCP Sensitivity Analysis Effect of Refrigerant Charge Cooling HP heating Backup heat LCCP per lifetime (kg_ Direct Indirect kg kg 5.25 kg 5.5 kg 4. kg 4.25 kg 4.5 kg 4.75 kg 4.5 kg 4.75 kg 5. kg 5.25 kg 4.75 kg 5. kg 5.25 kg 5.5 kg Refrigerant Charge (Capacity and COP changed) COP and capacity results with different refrigerant charge amount were used for LCCP evaluation Both direct and indirect emissions are increased 4.75 kg 5. kg 5.25 kg 5.5 kg 4. kg 4.25 kg 4.5 kg 4.75 kg 4.5 kg 4.75 kg 5. kg 5.25 kg 4.75 kg 5. kg 5.25 kg 5.5 kg Refrigerant Charge (Capacity and COP changed)

20 Conclusions 2 11 th IIR Gustav Lorentzen Conference on Natural Refrigerants In general, has about 4% emission reduction as compared with. Lower capacity refrigerants ( and ) have the reduction of around 17% and 27%, respectively. But their proper evaluation should be made after capacity matching. Mild area has lower emissions than that of cold and hot areas. has a high direct emission contribution (14.) while its alternatives have lower within 4%. COP improvement has a highest impact on emission reduction.

21 Thank You! Any Questions? 21