System drop-in tests of refrigerant blend R-125/R-143a/R-134a (44%/52%/4%) compared to R-502
- National Research Council Canada, Ottawa, Ontario (Canada). Inst. for Environmental Research and Technology
The near-azeotropic blend R-125/R-143a/R-134a (44%/52%/4%) is a long-term, zero-ozone-depletion-potential replacement for the low-temperature refrigerant R-502. This blend has recently been assigned refrigerant number R-404A by the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (ASHRAE). A series of tests has been completed comparing the system drop-in performance of this blend with that of R-502. The tests were carried out, under controlled conditions in a well-instrumented alternative-refrigerants test facility, using an open-drive reciprocating compressor and counterflow heat exchangers. Measurements were conducted at two different condensing temperatures--54.4 C (130.0 F) and 43.3 C (110.0 F). The 3 refrigerant-evaporating temperature was varied over a range from {minus}30.0 C to {minus}15.0 C ({minus}22.0 F to 5.0 F). The refrigerant superheat at the evaporator outlet was maintained at approximately 5.0 C (9.0 F), and the return gas temperature to the compressor was maintained at 18.3 C (65.0 F). The degree of liquid subcooling at the condenser outlet was varied between 6.0 C and 18.0 C (10.8 F and 32.4 F). Test data were used to compare important compressor performance characteristics, including shaft power, pressure ratio, and compressor discharge temperature. System performance characteristics were also measured, including evaporator capacity, refrigerant mass flow, and cooling coefficient of performance (COP). The effect of additional liquid subcooling on the evaporator capacity and COP was also evaluated.
- OSTI ID:
- 87375
- Report Number(s):
- CONF-950104--
- Country of Publication:
- United States
- Language:
- English
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