System Soft-optimization Tests of Refrigerant R-32 in a 6-ton Rooftop Packaged Air-Conditioner Mohammad Khawaldeh Director, Unitary & Applied Product Units
Presentation Outline Objectives Challenges Base Unit Information vs. Optimization of R-32 Test Lab and Test Setup Instrumentation Test Conditions Test Results Conclusion 2/2/2016 2
Objectives Evaluate the performance of the Low GWP alternative R-32 to replace R-410A refrigerant at high ambient conditions. Create a comparison between R-410A and R-32 refrigerants in terms of Capacity & EER at high ambient conditions. Build experience on R-32 system at high ambient conditions, to understand the required modifications on the existing R-410A system. 2/2/2016 3
Challenges Material availability, such as, Refrigerant, TXV & Compressor. Safety measures for mild flammable refrigerant. Testing condition stability at extreme high ambient. Cooling capacity decreases due to higher condensing temperature. Refrigerant and Oil decomposition at high discharge temperature. Viscosity of the oil decreases at high ambient. 2/2/2016 4
Base Unit - Equipment Description PTH006 Rooftop Packaged Air Conditioner Single Refrigerant Circuit Scroll Compressor Thermostatic Expansion Valve R-410A design 2/2/2016 5
Base Unit Information vs. Optimization of R-32 R-410A R-32 PTH006 Base Unit Information Optimization of R-32 Nominal Cooling Capacity 71,848 BTU/HR 78,343 BTU/HR Nominal Air Flow 2500 CFM 2500 CFM Compressor ZP61K5E ZP61KCE (Sample) Refrigerant Charge 295 Oz 260 Oz Expansion Valve Size TGEL 6.5 TGEL 4.5 Lubrication POE Oil /42 Oz /96 cst POE Oil /56 Oz/96 cst Super heat 11 ~15 ºF 11 ~15 ºF Subcooling 15 ~17 º F 15 ~17 º F Power Supply 460 V-3 ph-60 hz 460 V-3 ph-60 hz Evaporator Coil Condenser Coil Copper tube and aluminum fin, 8.0 ft²,3/8" tubes, 3 rows, 14 FPI Copper tube and aluminum fin, 12.7 ft²,3/8" tubes, 2 rows, 14 FPI 2/2/2016 6
Test Laboratory - IKHTIBAR Tests were held in Ikhtebar Lab Saudi Arabia Founded in 2006. It is the first independent laboratory for testing climate control solutions in the Middle East. It was constructed by Intertek Testing Services (ITS) as per ASHRAE-37 standard. Ikhtebar Lab has been accredited according to SASO/ISO17025 standard. Facility Calorimetric Test Rooms (3 NO) Psychrometric Test Rooms (3 NO) Chiller Test Facility Sound Lab Reliability Test Facility Application Used for testing the capacities of consumer range of air conditioners Tests Unitary range of air conditioning units up to 30 TR Measures the cooling capacity of chillers, up to 200 TR Consists of two reverberant sound rooms to measure sound power levels of air conditioners under load conditions and a hemi-anechoic facility to isolate and analyze the unit sound sources Qualifies window and mini-split air conditioners to sustain the severe ambient conditions by running rigorous tests of component cycling and durability 2/2/2016 7
Test Setup INDOOR ROOM OUTDOOR ROOM Data Measurement Locations Temperature Data Locations T#1 Evaporator Inlet Temperature P#1 Compressor Suction Pressure T#2 Evaporator Outlet Temperature P#2 Compressor Discharge Pressure T#3 Compressor Suction Temperature P#3 Condenser Outlet Pressure T#4 Compressor Discharge Temperature T#5 Condenser Outlet Temperature Pressure Data Locations Total 5 Total 3 Extra Measurements * Evaporator Air Inlet Temperature * Evaporator Air Outlet Temperature * Condenser Air Inlet Temperature * Condenser Air Outlet Temperature * Evaporator Air Flow * Condenser Air Flow 2/2/2016 8
Test Setup Indoor Room Outdoor Room Compressor Reading 1. Maintain the indoor air conditions 2. Measure the evaporator air flow 1. Maintain the outdoor air conditions 2. Measure the condenser air flow 1. Measure the suction and discharge pressure 2. Measure the discharge temperature 2/2/2016 9
Test Conditions AHRI 340/360 Standard for All Ambient Conditions Test Indoor Outdoor DB ( F) WB ( F) DB ( F) WB ( F) Operations T1 80 67 95 75 Cooling Capacity & EER T3 80 67 115 75 Cooling Capacity & EER Hot Ambient 80 67 125 75 Cooling Capacity & EER Extreme Ambient 80 67 130 75 Cooling Capacity & EER Low Ambient 1 80 67 81.5 NA IEER Low Ambient 2 80 67 68 NA IEER Low Ambient 3 80 67 65 NA IEER 2/2/2016 10
Test Results
Refrigerant Charge (Ib) Test Results - Refrigerant Charge 20 19 18 17 16-12 % 15 14 R410A 18.43 R32 16.25 R-32 charge is 12% lower than R-410A charge 2/2/2016 12
Lubricant Charge (Ib) Test Results - Lubricant Charge 4 3.5 3 2.5 2 1.5 1 0.5 0 R410A 1.71 R32 2.29 +34 % R-32 lubricant has larger lubricant charge by 34% more than R-410A R-32 prototype compressor has slightly lager displacement volume than R-410A compressor (7.18 ft 3 /min Vs 7.06 ft 3 /min ) 2/2/2016 13
Cooling Capacity ( Btu/hr) Test Results - Cooling Capacity 90000 80000 70000 60000 50000 40000 30000 20000 10000 +9% +10% +11% +12% +11% +12% +16% +13% 0 95 100 105 110 115 120 125 130 R410A 71848 70634 68217 65872 64706 61272 56472 54167 R32 78343 77619 75734 73936 71611 68378 65344 61467 Ambient Temperature (ºF) R-32 has higher capacity by 12% (Avg.) than R-410A. At high ambient condition, R-32 shows higher capacity (up to 16 %) 2/2/2016 14
Cooling Capacity ( Btu/hr) Test Results - Degradation on Cooling Capacity 90000 80000 70000 60000 50000 40000 30000 20000 10000 0-1% -3% -6% -9% -13% -17% -22% -2% -5% -8% -10% -15% -21% -25% 95 100 105 110 115 120 125 130 Ambient Temperature (ºF) R-410A Curve R-32 Curve R410A has reduction in capacity by 10% at 115 ºF ambient and 25% at 130ºF ambient 2/2/2016 15
EER ( Btu/hr/W) Test Results - Energy Efficiency Ratio 14.00 12.00 10.00 8.00 6.00 4.00 2.00 +2% +3% +4% +5% +4% +5% +10% +8% 0.00 95 100 105 110 115 120 125 130 R410A 12.19 11.46 10.51 9.67 8.98 8.09 7.03 6.41 R32 12.44 11.77 10.92 10.16 9.37 8.51 7.73 6.90 Ambient Temperature (ºF) R-32 has higher energy efficiency ratio by 5% (Avg.) than R-410A At high ambient condition, R-32 shows higher EER (up to 10 %) 2/2/2016 16
IEER Test Results - Integrated Energy Efficiency Ratio 15 14.5 +4% 14 13.5 13 12.5 12 R410A 14.38 R32 13.85 R410A has better integrated energy efficiency ratio (IEER) by 4% than R32 2/2/2016 17
Suction Pressure ( Psig) Test Results - Suction Pressure 155.0 150.0 145.0 +6 +2 +3 +3 +3 +4 +4 +3 140.0 135.0 130.0 95 100 105 110 115 120 125 130 R410A 139.3 142.5 143.4 144.4 145.1 145.8 147.5 148.7 R32 144.9 144.9 146.2 147.5 148.3 150.0 151.2 152.1 Ambient Temperature (ºF) R-32 has suction pressure higher by +4 Psi (Avg.) than R-410A 2/2/2016 18
Discharge Pressure (Psig) Test Results - Discharge Pressure 700.0 600.0 500.0 400.0 300.0 200.0 100.0 +12 +24 +20 +27 +29 +31 +30 +32 0.0 95 100 105 110 115 120 125 130 R410A 403.1 422.1 454.3 476.7 504.9 533.7 567.9 599.4 R32 415.4 446.5 474.7 503.7 533.7 565.1 597.5 631.0 Ambient Temperature (ºF) R-32 has discharge pressure higher by +26 Psi (Avg.) than R-410A At 130 ºF ambient, R-32 discharge pressure is +32 Psi higher than R-410A 2/2/2016 19
Discharge Temperature ( ºF) Test Results - Discharge Temperature 300.0 250.0 200.0 150.0 100.0 50.0 +29 +31 +33 +34 +36 +38 +38 +44 0.0 95 100 105 110 115 120 125 130 R410A 159.4 166.2 172.3 180.2 186.8 194.4 203.3 211.6 R32 188.2 196.9 205.5 213.9 223.2 232.0 241.8 255.9 Ambient Temperature (ºF) R-32 has discharge temperature higher by +35 ºF (Avg.) than R-410A At 130 ºF ambient, R-32 discharge temperature is +44 ºF higher than R-410A 2/2/2016 20
Conclusions R-32 refrigerant is compatible to the existing of R-410A system with minor modifications. Unit has been tested up to 130 ºF ambient without any fault or tripping due to optimized condenser design. R-32 has better performance and efficiency than R-410A at high ambient. R-32 performance results may improve as the R-32 compressor design is optimized. R-32 systems need additional oil cooling or discharge Gas cooling system to reduce the high discharge temperature at high ambient conditions. 2/2/2016 21
Thank you.