Abstract
Carbon dioxide is one of the most hopeful refrigerants because of less emission of greenhouse gases. But when carbon dioxide is used in refrigeration cycle, the energy loss at the expansion valve is increased by three times compared with refrigerants R-134a. This lowers the coefficient of performance. We had been researching the two-phase ejector that recovers this energy to deduce the compressor work. On the other hand, the regeneration is effective for the conventional refrigeration cycle. To elucidate the connection between the two-phase ejector system and the regeneration system, the theoretical research is carried out in this study. The coefficients of performance of the regeneration cycle with conventional expansion valve are shown to be considerably lower than that of the ejector system.
