Thermodynamic analyses of a modified ejector enhanced dual temperature refrigeration cycle for domestic refrigerator/freezer application

This paper presents a modified ejector enhanced dual temperature refrigeration cycle (MERC) with mixture refrigerant R290/R600a for domestic refrigerator/freezer application. The proposed cycle eliminates the vapor-liquid separator and allows low boiling component refrigerant R290 enters the freezer evaporator, which results in an enhancement of evaporating pressure at the same evaporating temperature. The thermodynamic modeling through energetic and exergetic analysis method is employed to evaluate the cycle performance of MERC and compared with that of basic ejector enhanced dual temperature refrigeration cycle (BERC). The simulation results show that the COP and q(ev) of MERC are improved by 23.1% and 34.7% compared with BERC under the typical operating condition. And every component of MERC shows relatively lower level of exergy destruction than that of BERC, which has 22.9% improvement in exergy efficiency eta(ex). Overall, the MERC could achieve higher cycle performance when a lower cooling capacity ratio of freezer evaporator to refrigerating evaporator is demanded. Furthermore, the highest COPs and eta(ex)could be obtained at the optimal R290 mass fraction of 0.7. The theoretical results reveal the practical application potential of MERC in the domestic refrigerator/freezer. (C)& nbsp;2021 Elsevier Ltd. All rights reserved.