Performance Analysis of Transcritical CO2 Compression Cycle

With the growing awareness of dual threats of global warming and ozone depletion, environmentally benign natural refrigerants have attracted considerable attention. As a natural refrigerant, CO2 is a potential substitute for synthesized refrigerants with favorable environmental properties. In order to improve the performance of the transcritical CO2 compression cycle, the mathematical models of three kinds single stage cycle and three kinds two stage cycle were developed and the performances were analyzed. The results showed that the optimum intermediate pressure affects the performance of transcritical CO2 two stage compression cycle. The system COP increases with the evaporating temperature rises. Oppositely, the COP decreases with the cooled temperature rises. Some fundamental data were obtained for improving cycle performance and developing the products of CO2 refrigeration air condition and heat pumps.