Performance evaluation of an ejector subcooling refrigeration cycle with zeotropic mixture R290/R170 for low-temperature freezer applications

In this study, an ejector subcooling refrigeration cycle (ESRC) with zeotropic mixture R290/R170 for low-temperature freezer applications is proposed. In the ESRC, an ejector is introduced with a new cycle configuration to reduce the throttling loss and lift the suction pressure of compressor. A major advantage of the proposed cycle is that it does not need any a vapour-liquid separator. The performances of the ESRC, the baseline vapor-compression refrigeration cycles (BVRC) and the standard ejector-expansion refrigeration cycle (EERC) are compared utilizing energy and exergy analysis methods, and several important parameters are also discussed in detail. The results indicate that the ESRC is feasible and there are obvious performance improvements in terms of the COP, volumetric refrigeration capacity and exergic efficiency. Especially, the ESRC can achieve COP improvements of 17.4% and 26.6% compared with the EERC and BVRC in typical operating conditions, respectively. In general, the performance characteristics of the proposed cycle demonstrate its potential applications in low-temperature freezers.