Dr. Omar Abdelaziz Dr. Som Shrestha - · PDF file · 2016-02-03Dr. Omar Abdelaziz...

ORNL is managed by UT-Battelle

for the US Department of Energy

Soft-optimization

Test of R-410A and

R-22 Alternatives

in Mini-split Air-

Conditioners

Dr. Omar Abdelaziz

Dr. Som Shrestha

AHRI Low-GWP AREP Conference

January 21, 2016. Orlando, FL

2Alternative Refrigerant Evaluation for High Ambient

Temperature Environments

Program Objective

• To evaluate the soft-optimized performance of mini-split air conditioners with alternative lower-GWP refrigerants to R-22 and R-410A at high-ambient temperature

• Help evaluate the viability of using alternative lower-GWP refrigerants in said markets to avoid a costly two-step transition from HCFC to HFC and then from HFC to lower-GWP refrigerants

http://www.unep.org/dewa/Portals/67/pdf/HFC_report.pdf

http://www.unep.org/dewa/Portals/67/pdf/HFC_report.pdf



Equipment

• Carrier mini-split AC systems with rotary compressors designed for high ambient applications

– R-22 Unit

• Capacity* = 18.5 kBtu/h (5.42 kW)

• EER* = 9.7 (COP ~ 2.84)

– R-410A Unit

• Capacity* = 18 kBtu/h (~ 5.28kW)

• EER* = 12.0 (COP ~ 3.52)

*Rated at ISO 5151 T1 (Indoor DBT 27°C (80.6°F), WBT 19°C (66.2°F)



R-22 Alternative Refrigerants

Refrigerant Manufacturer

ASHRAE

Safety

Class

GWP

AR4 AR5

R-22a - A1 1,810 1,760

N-20Bb Honeywell A1 988 904

DR-3b Chemours A2L 148 146

ARM-20Bb Arkema A2L 251 251

L-20Ab Honeywell A2L 295 295

DR-93b Chemours A1 1,258 1,153

R-290a - A3 3 3a Sources: IPCC AR4, 2007; IPCC AR5, 2013b GWP values for refrigerant blends not included in IPCC reports are

calculated as a weighted average using manufacturer-supplied compositions.



R-410A Alternative Refrigerants

a Sources: IPCC AR4, 2007; IPCC AR5, 2013b GWP values for refrigerant blends not included in IPCC reports are

calculated as a weighted average using manufacturer-supplied compositions.

Refrigerant Manufacturer

ASHRAE

Safety

Class

GWP

AR4 AR5

R-410Aa - A1 2088 1924

ARM-71Ab Arkema A2L 460 461

R-32a Daikin A2L 675 677

DR-55b Chemours A2L 698 676

L41-2b Honeywell A2L 583 572

HPR-2Ab Mexichem A2L 600 593



R-22 Experiment Setup



R-410A Experimental Setup



Soft optimization

• Optimization sequence:

– Calculate capillary tube length

– Calculate charge

– Adjust charge

– Adjust capillary tube

• Check performance at T3 to ensure superheat and subcooling

Cap tube header



Experiment Uncertainty

R-22 Unit

• Airside Uncertainty:

– Capacity: ±2.3%

– COP: ±2.4%

• Refrigerant side uncertainty:


– COP: <±0.8%

• Energy balance between air side and refrigerant side measurements:

– AHRI A: -2.30% to 2.89%

– AHRI B: -1.99% to 2.37%

R-410A Unit

• Airside uncertainty:


– COP: ±1.6%

• Refrigerant side uncertainty:


– COP: ±0.81%

• Energy balance between air side and refrigerant side measurements:

– AHRI A: -3.60% to 0.05%

– AHRI B: -3.97% to 0.05%



Test Conditions

Test

Condition

Outdoor Indoor

DBT DBT WBT RHa

°C (°F) °C (°F) °C (°F) %

AHRI Bb 27.8 (82.0) 26.7 (80.0) 19.4 (67.0) 50.9

AHRI Ab 35.0 (95.0) 26.7 (80.0) 19.4 (67.0) 50.9

T3*c 46 (114.8) 26.7 (80.0) 19 (66.2) 48.8

T3d 46 (114.8) 29 (84.2) 19 (66.2) 39.0

Hot 52 (125.6) 29 (84.2) 19 (66.2) 39.0

Extreme 55 (131.0) 29 (84.2) 19 (66.2) 39.0a RH at 0.973 atm (14.3 psi), typical barometric pressure in the labb Per AHRI Standard 210/240c T3* is a modified T3 condition where the indoor settings are similar to the AHRI conditionsd Per ISO 5151 standard



R-22 Unit

Refrigerant

Capillary

Tube Length,

mm (Inch)

Charge Mass,

kg (oz.)

R-22 (Baseline) 508 (20) 1.417 (50)

N-20B 152 (6) 2.087 (73.6)

DR-3 178 (7) 2.007 (70.8)

ARM-20B 178 (7) 1.588 (56)

L-20A (R-444B) 356 (14) 1.568 (55.3)

DR-93 152 (6) 1.828 (64.5)

R-290 203 (8) 0.731 (25.8)

ID: 2 mm (0.079”) for R-22, 1.65 mm (0.065”) for alternative refrigerants



Impact on Compressor Discharge

Temperature (Tcomp

)

-20

-15

-10

-5

0

5

10

B A T3* T3 Hot Extreme

T com

p–

T com

p, b

ase

line

, °C

L-20A (R-444B) DR-3 N-20B

ARM-20B R-290/POE DR-93



Performance Relative to R-22 at AHRI A

Conditions

L-20A

DR-3

N-20BARM-20B

R-290

DR-9380%

85%

90%

95%

100%

105%

110%

80% 85% 90% 95% 100% 105%

CO

P

Cooling Capacity



Performance Relative to R-22 at ISO T3

Conditions

L-20A

DR-3

N-20BARM-20B

R-290

DR-93

80%

85%

90%

95%

100%

105%

110%

80% 85% 90% 95% 100% 105%

CO

P

Cooling Capacity



Performance Relative to R-22 at Extreme

Conditions

L-20A

DR-3

N-20B

ARM-…

R-290

DR-93

80%

85%

90%

95%

100%

105%

110%

80% 85% 90% 95% 100% 105%

CO

P

Cooling Capacity



R-22 Conclusions

• The A1 alternative refrigerants lagged in performance

• Two A2L refrigerants showed capacity within 5% and efficiency within approximately 10% of the baseline system at ambient temperature at or above 46°C

• The A3 refrigerant (R-290) exhibited higher efficiency and capacity within 9% of the baseline



R-410A Unit

Refrigerant

Capillary Tube

Length, mm

(Inch)

Charge Mass,

kg (oz.)

R-410A 673 (26.5) 0.936 (33)

ARM-71A 610 (24) 0.765 (27)

R-32 1016 (40) 0.709 (25)

DR-55 660 (26) 0.811 (28.6)

L41-2 (R-447A) 864 (34) 0.780 (27.5)

HPR-2A 965 (38) 0.808 (28.5)

ID: 2 mm (0.079”) for R-410A, 1.65 mm (0.065”) for alternative refrigerants



Impact on Compressor Discharge

Temperature

0

5

10

15

20

25


T com

p–

T com

p, b

ase

line, °

C

R-32 DR-55 L41-2 (R-447A) ARM-71a HPR-2A



Performance Relative to R-410A at AHRI A

Conditions

R-32DR-55

L41-2

ARM-71AHPR-2A

90%

95%

100%

105%

110%

80% 90% 100% 110%

CO

P

Cooling Capacity



Performance Relative to R-410A at ISO T3

Conditions

R-32

DR-55L41-2

ARM-71A

HPR-2A

90%

95%

100%

105%

110%

80% 90% 100% 110%

CO

P

Cooling Capacity



Performance Relative to R-410A at

Extreme Conditions

R-32

DR-55L41-2

ARM-71A

HPR-…

90%

95%

100%

105%

110%

80% 90% 100% 110%

CO

P

Cooling Capacity



R-410 Conclusions

• R-32 showed better capacity and efficiency; but resulted in higher compressor discharge temperature

• DR-55 had consistently higher COPs and matched the capacity at higher ambient conditions.

• HPR-2A’s performance exceeded the baseline at all ambient temperatures higher than 35°C.

• R-447A and ARM-71A had lower capacity but R-447A had better COP than the baseline at ambient temperatures higher than 46°C.



Overall Conclusions

• The results are for soft optimized systems only; efficiency and capacity of the alternative refrigerants can be expected to improve through design modifications before introducing a new product to market.

• Multiple alternatives for R-22 performed well, and most R-410A alternatives matched or exceeded the performance of R-410A. These may be considered as prime candidate lower GWP refrigerants for high-ambient-temperature environments.



Acknowledgment

• US DOE/BTO Support: Dr. Patrick Phelan, Mr. Antonio Bouza

• Ms. Jaqueline Wong at the Executive Office of the President who coordinated to build support among hot climate countries for the accelerated transition

• Navigant Consulting: Mr. William Goetzler, Mr. Matthew Guernsey, Theo Kassuga

• ORNL: Randy Linkous, Jeffrey Munk, and Anthony Gehl

• Ankit Sethi at Honeywell

Panel of International Experts:

Dr. Radhey Agarwal (India)

Dr. Karim Amrane (USA)

Dr. Enio Bandarra (Brazil)

Dr. J. Bhambure (India)

Mr. Ayman El-Talouny (UNEP)

Dr. Tingxun Li (China)

Dr. Samuel Yana Motta

Mr. Maher Moussa (KSA)

Mr. Ole Nielsen (UNIDO)

Mr. Tetsuji Okada (Japan)

Dr. Alaa Olama (Egypt)

Dr. Alessandro Giuliano Peru (Italy)

Dr. Suely M. Carvalho (IPEN, Brazil) and

Dr. Patrick Phelan (Department of Energy, USA)



References

• IPCC, 2007: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA; section 2.10.2: Direct Global Warming Potentials. Available: https://www.ipcc.ch/publications_and_data/ar4/wg1/en/contents.html

• IPCC, 2013. Myhre, G., D. Shindell, F.-M. Bréon, W. Collins, J. Fuglestvedt, J. Huang, D. Koch, J.-F. Lamarque, D. Lee, B. Mendoza, T. Nakajima, A. Robock, G. Stephens, T. Takemura and H. Zhang, 2013: Anthropogenic and Natural Radiative Forcing. In: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley(eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA. Available: https://www.ipcc.ch/pdf/assessment-report/ar5/wg1/WG1AR5_Chapter08_FINAL.pdf

https://www.ipcc.ch/publications_and_data/ar4/wg1/en/contents.html

https://www.ipcc.ch/pdf/assessment-report/ar5/wg1/WG1AR5_Chapter08_FINAL.pdf



Discussion

Omar Abdelaziz, [email protected]

Som Shrestha, [email protected]

Visit our website: www.ornl.gov/buildings

Follow me on Twitter: @somsgrFollow us on Twitter: @ORNLbuildings

The detailed report is available to download at AHRI web site

http://www.ahrinet.org/App_Content/ahri/files/RESEARCH/AREP_

Final_Reports/AHRI_Low_GWP_AREP_Rpt_062.pdf

mailto:[email protected]

mailto:[email protected]

http://www.ahrinet.org/App_Content/ahri/files/RESEARCH/AREP_Final_Reports/AHRI_Low_GWP_AREP_Rpt_062.pdf

Additional/Backup

Slides



Test Chamber

Multi-Zone Environmental Chambers,

• Outdoor chamber is 6.1×4.6 m

• DBT is controlled at −23 to 55°C (−10 to 131°F) and relative humidity at 30 to 90%.

• The 8.5 m square indoor chamber can be divided into up to individually controlled four spaces



Instrumentation: R-22 system

• Custom built air enthalpy tunnel complying with AHRI Standard 210/240 and ANSI/ASHRAE Standard 37: 0.4%

• Coriolis mass flow meter: CMF25 with ±0.5% error

• Pressure sensors: ±0.08% BSL

• T-Type thermocouples: ±0.28°C (0.5°F)

• Dew point sensors: ±0.2°C (0.36°F)

• Barometric pressure sensors: ±0.6 hPa/mb

• Power meters: ±0.2% reading

All Instrumentation were calibrated either at ORNL metrology or third party calibration laboratory prior to initiating the experimental campaign



Instrumentation: R-410A system

• Code Tester complying with AHRI Standard 210/240 and ANSI/ASHRAE Standard 37

• Coriolis mass flow meter: CMF25 with ±0.5% error

• Pressure sensors: ±0.08% BSL

• RTD: ±0.15°C (0.27°F) @ 0°C

• Wet bulb sensors: ±0.15°C (0.27°F) @ 0°C

• Barometric pressure sensors: ±0.6 hPa/mb

• Power meters: ±0.2% reading

All Instrumentation were calibrated either at ORNL metrology or third party calibration laboratory prior to initiating the experimental campaign



Impact on Capacity

0

2

4

6

8


Co

olin

g C

apac

ity,

kW

R-22/mineral oil L-20A (R-444B) DR-3

N-20B ARM-20B R-290/POE

DR-93



Impact on COP

0.0

1.0

2.0

3.0

4.0

5.0


CO

P

R-22/mineral oil L-20A (R-444B) DR-3

N-20B ARM-20B R-290/POE

DR-93



Impact on Capacity

0

1

2

3

4

5

6


Co

olin

g C

apac

ity,

kW

R-410A R-32 DR-55

L-41 (R-447A) ARM-71a HPR-2A



Impact on COP

0

1

2

3

4

5


CO

P

R-410A R-32 DR-55

L-41 (R-447A) ARM-71a HPR-2A



Temperature glide at the evaporator for

R-22 and its alternatives



Temperature glide at the evaporator for

R-410A and its alternatives

Dr. Omar Abdelaziz Dr. Som Shrestha - · PDF file · 2016-02-03Dr. Omar Abdelaziz...

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