Study of heat pump performance using mixtures of R32/R134A and R32/R125/R134A as drop-in' working fluids for R22 with and without a liquid-suction heat exchanger

Technical Report · Wed Dec 01 04:00:00 EST 1993

OSTI ID:7187554

Rothfleisch, P I; Didion, D A

A ductless mini-split residential heat pump with a modified indoor coil was utilized to compare the performance of R22 and a mixture of 34% R32/66% R134a by weight. This test was intended to serve as an indicator of 'drop-in' performance so the system was optimized for each refrigerant by varying only the charge mass and expansion valve setting. At the 27.8 C (82 F) cooling test condition the capacity and COP of the mixture were 94% and 90% of the values for R22, respectively. Additional tests were conducted with a liquid-suction intracycle heat exchanger. The modified system was operated with both single-phase and two-phase refrigerant entering the low pressure side of the liquid-suction heat exchanger. The addition of the liquid-suction heat exchanger showed a minimal performance improvement with the performance of the two-phase variation being slightly higher. The best performing liquid-suction heat exchanger variant (two-phase refrigerant on the low pressure side) was also run with a ternary mixture of 30% R32/10% R125/60% R134a, by weight. The results for this mixture were similar to the binary mixture.

• Research Organization: National Inst. of Standards and Technology (BFRL), Gaithersburg, MD (United States). Building Environment Div.
• OSTI ID: 7187554
• Report Number(s): PB-94-218559/XAB; NISTIR--5321
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
320303* -- Energy Conservation
Consumption
& Utilization-- Industrial & Agricultural Processes-- Equipment & Processes
FLUIDS
HEAT EXCHANGERS
OPTIMIZATION
PERFORMANCE TESTING
REFRIGERANTS
TESTING
WORKING FLUIDS