Theoretical study on a novel dual-nozzle ejector enhanced refrigeration cycle for household refrigerator-freezers

In this study, a novel dual-nozzle ejector enhanced refrigeration cycle is presented for dual evaporator household refrigerator-freezers. The proposed ejector equipped with two nozzles can efficiently recover the expansion work from cycle throttling processes and enhance cycle performances. The performances of the novel cycle are evaluated by using the developed mathematical model, and then compared with that of the conventional ejector enhanced refrigeration cycle and basic vapor-compression refrigeration cycle. The simulation results show that for the given operating conditions, the coefficient of performance (COP) of the novel cycle using refrigerant R134a is improved by 22.9-50.8% compared with that of the basic vapor-compression refrigeration cycle, and the COP improvement is 10.5-30.8% larger than that of the conventional ejector enhanced refrigeration cycle. The further simulation results of the novel cycle using refrigerant R600a indicate that the cycle COP and volumetric refrigeration capacity could be significantly improved.