Analysis of a refrigeration cycle driven by refrigerant steam turbine

Abstract

The objectives of this paper are to develop a novel cycle with refrigerant Rankine and refrigeration cycles, and to discuss the thermodynamic analysis of the cycle and the adequacy of the development. The combined cycle uses only one working fluid, has a simple mechanical system and does not have abrading parts. Three different refrigerants are evaluated to find the best candidate for the novel combined cycle—R123, R134a and R245ca. It is found that the R123 cycle gives the highest cycle efficiency among all cycles considered in the present study. The base cycle has a low efficiency because of the high temperature at the turbine outlet. By recovering the heat at the turbine outlet, the overall COP increases by 47% in case of the R245ca cycle. In the base cycle, COP depends mostly on the boiler pressure, while in the modified cycle with the recuperator, the cycle efficiency depends mostly on the boiler temperature. Considering the cycle efficiency and environmental issues, it is concluded that R245ca is the most promising refrigerant out of the cycles considered in the present paper.