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Study of a Water-to-Water Heat Pump Using Flammable Refrigerants.


pdf icon Study of a Water-to-Water Heat Pump Using Flammable Refrigerants. (832 K)
Payne, W. V.; Domanski, P. A.; Muller, J.

Natural Working Fluids '98 IIR-Gustav Lorentzen Conference. IIF-IIR Sections B and E. Proceedings. June 2-5, 1998, Oslo, Norway, 1998.

Keywords:

heat pumps; refrigerants; brazed plate heat exchangers; entropic average; hydrocarbons; water-to-water heat pumps; zeotropic

Abstract:

This investigation compared the performance of R22 to the performance of R290 and that of flammable zeotropic mixtures, R32/290 and R32/152a. The tests were conducted in a test apparatus specially designed to simulate a residential water-to-water heat pump. Brazed plate heat exchangers used as the evaporator and condenser allowed for counter-flow heat transfer between the refrigerant and indoor-loop and outdoor-loop heat-transfer fluids. The performance of the system was characterized by air-side capacity and Coefficient of Performance (COP) at different compressor speeds. Performance comparisons at a constant capacity were also provided. In the cooling mode at a constant-capacity, the R32/290 (50/50) mixture produced the highest COP; 8% higher than R22. In the heating mode, the COP of R290 was the highest; from 6% to 8% higher than that of the remaining fluids. The cooling COP of R32/290 was 13% lower and the heating COP of R290 was 1% higher than the respective COPs of R22 in the reference water-to-air system.