Study of a Water-to-Water Heat Pump Using Flammable Refrigerants.
Study of a Water-to-Water Heat Pump Using Flammable
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.
heat pumps; refrigerants; brazed plate heat exchangers;
entropic average; hydrocarbons; water-to-water heat
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