Influence of the Leakage of Natural Non-azeotropic Mixture Refrigerant R600a/CO2 on System Performance of Auto-cascade Refrigeration Cycle

摘要

This paper investigated the leakage of nature non-azeotropic mixture refrigerant R600a/CO2 in an auto-cascade refrigeration cycle.Simulative analyses on the auto-cascade refrigerating cycle were performed to discuss the influence of leakage in different part on composition of refrigerant was analyzed based on the isothermal leakage of non-azeotropic refrigerant in two-phase area.The results show that the influence of leakage at exit of condenser,vapor-liquid separator and evaporator on the refrigerant composition is bigger than other points and the exit of evaporator is maximal.When the composition of refrigerant changes much due to the leakage,the adjusting ability of capacity and pressure ratio of compressor reduces obviously.Consequently,the system can not meet the requirement of working condition and the performance of cycle is worsening.The studies are useful for the application and popularization of ACR system and natural refrigerant.