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R-410A Alternative Lower GWP Refrigerants Drop in Testing: System and ComponentsOmar Abdelaziz, and Som Shrestha
January 16th, 2014New York City
2 R-410A Alternative Lower GWP Refrigerants Drop in Testing: System and Components
Overview
• System Drop-In Testing• Indoor Heat Exchanger Evaluation• Compressor Testing
3 R-410A Alternative Lower GWP Refrigerants Drop in Testing: System and Components
System Drop-In Testing
4 R-410A Alternative Lower GWP Refrigerants Drop in Testing: System and Components
System Description
• 5-TR heat pump unit– Outdoor unit: fixed capacity compressor, single speed fan– Single zone air handler: single
speed blower, draw-through configuration
• R410A baseline: GWP = 2100†
• R32/R152a (95% R32 -5%R152a): GWP ~ 687
† UNEP 2010
5 R-410A Alternative Lower GWP Refrigerants Drop in Testing: System and Components
Heat Exchanger
• A-Coil – 8 circuits– OD = 3/8” (9.53 mm)– Tube thickness = 0.012”
(0.305 mm)
• Air flows from bottom to top• R410A TXV, set at ~ 5ºF
(3ºC) superheat
6 R-410A Alternative Lower GWP Refrigerants Drop in Testing: System and Components
System Setup
7 R-410A Alternative Lower GWP Refrigerants Drop in Testing: System and Components
Results – System performance
0
10
20
30
40
50
60
70
80
A B C H1 H2 H3
Air-S
ide H
eat C
apac
ity (k
Btu/
W·h
)
R410A R32/R152a
02468
1012141618
A B C H1 H2 H3
EER
(Btu
/W·h
)
R410A R32/R152a
8 R-410A Alternative Lower GWP Refrigerants Drop in Testing: System and Components
Additional System Performance Indicators
050
100150200250300350400450
A B C H1 H2 H3
Disc
harg
e Pre
ssur
e (ps
i)
R410A R32/R152a
0
1000
2000
3000
4000
5000
6000
A B C H1 H2 H3
Tota
l Pow
er C
onsu
mpt
ion
(W)
R410A R32/R152a
9 R-410A Alternative Lower GWP Refrigerants Drop in Testing: System and Components
Compressor Discharge Temperature
100
120
140
160
180
200
220
A B C H1 H2 H3
Com
pres
sor D
ischa
rge T
empe
ratu
re, °
F
R410A R32/R152a
10 R-410A Alternative Lower GWP Refrigerants Drop in Testing: System and Components
Indoor HX Evaluation
1.51.61.71.81.9
22.12.22.32.42.5
100 125 150 175 200 225
Over
all U
A, kW
/m2
Mass Flux, kg/m2.s
Evaporating Mode
R410AR32/R152a
11 R-410A Alternative Lower GWP Refrigerants Drop in Testing: System and Components
Indoor HX Evaluation
0.50.55
0.60.65
0.70.75
0.80.85
0.90.95
50 75 100 125 150
Over
all U
A, kW
/m2
Mass Flux, kg/m2.s
Condensing Mode
R410AR32/R152a
12 R-410A Alternative Lower GWP Refrigerants Drop in Testing: System and Components
Conclusions
• R32/R152a (95.22/4.78 by mass) was tested as a drop-in replacement to R410A
• R32/R152a has higher volumetric capacity and lower pressure drop through heat exchanger
• R32/R152a exhibited higher or similar system capacity for all test conditions
• In the evaporating mode, R32/R152a had comparable overall heat transfer characteristics to R410A even at much lower mass flux
• In the condensing mode, R32/R152a showed lower overall UA (5 to 21% lower) than R410A
13 R-410A Alternative Lower GWP Refrigerants Drop in Testing: System and Components
Compressor Calorimeter Testing
14 R-410A Alternative Lower GWP Refrigerants Drop in Testing: System and Components
Tested Refrigerants
Refrigerant ComponentsMass Fraction, % GWP100(†)
R-410a R-32/R-125 50/50 2100R-32 R-32 100 716DR-5 R-32/R-1234yf 72.5/27.5 520*L-41a R-32/R-1234yf/R-1234ze(E) 73/15/12 524*R-32/R-134a R-32/R-134a 94.07/5.93 755*† GWP100 based on UNEP, 2010* Calculated based on the GWP values of pure refrigerants and their mass fraction in the blend
15 R-410A Alternative Lower GWP Refrigerants Drop in Testing: System and Components
Results
16 R-410A Alternative Lower GWP Refrigerants Drop in Testing: System and Components
Results
17 R-410A Alternative Lower GWP Refrigerants Drop in Testing: System and Components
Results
18 R-410A Alternative Lower GWP Refrigerants Drop in Testing: System and Components
Results – R32/R134a
Test ConditionEER Capacity Discharge
TemperatureEvap 45°F/ Cond 130°F -2.20% -0.80% +37°REvap 50°F/ Cond 100°F -4.30% -2.8 +22°ROver the range -5.2% to -1.4% -4.9% to +0.3% +16 to +50°R
Deviation from R-410A performanceDeviation from R-410A performance
19 R-410A Alternative Lower GWP Refrigerants Drop in Testing: System and Components
Conclusions
• R-32 resulted in capacity gain at the cost of slight efficiency loss and higher compressor discharge temperature
• DR-5 resulted in moderate capacity loss, less than 5% penalty in EER with increased discharge temperature within 20°R
• L-41a resulted in the most capacity degradation; however it behaved exceptionally well at high saturation discharge temperature (>130°F)
• At all test conditions, the EER with R-32/134a was lower than that with R-410A (by 1.4 to 5.2%). At higher discharge dew point temperatures, the ratio generally increased as the suction dew point temperature increased
20 R-410A Alternative Lower GWP Refrigerants Drop in Testing: System and Components
Acknowledgements
• The authors would like to acknowledge funding from DOE-BTP and thank Mr. Antonio Bouza for his support
• The authors would like to thank Dr. Isaac Mahderekal, Mr. Vishaldeep Sharma, Randy Linkous and Brian Goins (ORNL), Kyle Karber (Post Graduate Research Associate), and Evelyn Tio for their technical support
21 R-410A Alternative Lower GWP Refrigerants Drop in Testing: System and Components
Bibliography
• Open Source Life Cycle Climate Performance Design Tool: http://lccp.umd.edu/ornllccp/• Evelyn Tio, Randy Linkous, Neal Durfee, Omar Abdelaziz, 2012. “System Drop-in Test of R-32/R-152a
(95/5) in a 5-ton Air Source Heat Pump”, TEST REPORT #3, Air-Conditioning, Heating, and Refrigeration Institute Low-GWP Alternative Refrigerants Evaluation Program http://www.ahrinet.org/App_Content/ahri/files/RESEARCH/AREP_Final_Reports/AHRI%20Low-GWP%20AREP-Rpt-003.pdf
• UNEP 2010. “2010 Report of the refrigeration, air conditioning and heat pumps technical options committee; Chapter 2, Refrigerants.” United Nations Environment Programme (UNEP) Ozone Secretariat, Nairobi, Kenya, http://ozone.unep.org/teap/Reports/RTOC/RTOC-Assessment-report-2010.pdf
• Som Shrestha, Isaac Mahderekal, Vishaldeep Sharma, Omar Abdelaziz, 2013. “Compressor Calorimeter Test of R-410A Alternatives R-32, DR-5, and L-41a”, TEST REPORT #11, Air-Conditioning, Heating, and Refrigeration Institute Low-GWP Alternative Refrigerants Evaluation Program http://www.ahrinet.org/App_Content/ahri/files/RESEARCH/AREP_Final_Reports/AHRI%20Low-GWP%20AREP-Rpt-011.pdf
22 R-410A Alternative Lower GWP Refrigerants Drop in Testing: System and Components
Questions?
Omar [email protected]
23 R-410A Alternative Lower GWP Refrigerants Drop in Testing: System and Components
Appendix
24 R-410A Alternative Lower GWP Refrigerants Drop in Testing: System and Components
Heat Pump Drop-In Test Instrumentation
• Airflow: Self-averaging Pitot, ±2% of reading• Refrigerant mass flow rate (liquid line): Coriolis flow and
density, bi-direction calibration, ±0.5% of reading• Refrigerant pressure measurement: ±0.08% Full scale of BSL
with ±1% span shift • Indoor airside temperature and relative humidity
measurements: ±0.15°C and ±1.5% RH • Refrigerant side temperature measurements: in-stream T-type
thermocouple ±1°F
25 R-410A Alternative Lower GWP Refrigerants Drop in Testing: System and Components
Heat Pump Drop-In Test Instrumentation
• Outdoor airside measurement: T-type thermocouple grid ±1°F• Power measurement:
– Compressor: 0-20 kW ±0.5% F.S.– Outdoor Fan: 0-1 kW ±0.5% F.S.– Indoor Blower: 0-500 W ±0.5% F.S.
• Uncertainty propagation for the R410A Cooling Test A based on air side performance is‡:– Q=62933 [Btu/hr] ±881 (±1.4%)– EER=14.12 [Btu/hr-W] ±0.201 (±1.42%)
‡ Based on averaging 82 data points
26 R-410A Alternative Lower GWP Refrigerants Drop in Testing: System and Components
Compressor Calorimeter Test Setup
• Test condition:– 70°F to 140°F SDT in 10°F
increments – 10°F to 55°F SST in 5°F
increments
27 R-410A Alternative Lower GWP Refrigerants Drop in Testing: System and Components
Compressor Calorimeter Instrumentation
The measured cooling capacity and EER were within 2.7% and 1.0%, respectively, of the manufacturer’s data.Intermediate tests confirmed repeatability of cooling capacity within 1.5% and EER within 2% at standard test conditions. Properties of refrigerants were calculated using REFPROP version 9.0 (Lemmon et al., 2010). Interaction parameters and “mixture” files provided by the refrigerant manufacturers were used in REFPROP to calculate properties of the alternative refrigerants (except for R-32 and R-32 + R-134a mixture) tested.
Instrument Measured AccuracyRTDs Temperature ± 0.4°FMass Flow Sensor Refrigerant mass flow rate ±0.10%
Power and Energy Meter Compressor and evaporator power ±0.5%
Pressure Transmitter Refrigerant pressure, high pressure side 0.25% F.S. [750 psia]
Pressure Transmitter Refrigerant pressure, low pressure side 0.25% F.S. [200 psia]