GWP, R404A, Screw compressor, Scroll compressor, Economizer, Transport refrigeration
Two economizer style compressors are explored, where the high pressure liquid is sub-cooled with a heat exchanger while the evaporation side in the heat exchanger is connected to an intermediate port with higher pressure than the suction pressure and lower pressure than the discharge pressure. One of the compressors is a screw compressor and the other one is a scroll compressor. One of the compressors is an open shaft compressor and the other one is a hermetic style compressor. Both compressor styles have been modeled based on test data with R404A and at conditions mainly corresponding to TRU (transport refrigeration unit) applications. Those compressor models have been used to explore lower GWP refrigerants such as R407A, R407F, N-40a, DR7 and DR33. For each compressor model each alternative refrigerant is compared with the baseline refrigerant R404A, based on capacity, coefficient of performance and discharge temperature. GWP of the refrigerants are compared as well. There is also some discussion relative to the indirect GWP and how it can correlate to the compressors coefficient of performance.