Comparative Study of Supercritical CO2 Refrigeration Cycles from Energy, Exergy, Economic and Environmental Points of View

In this work, a comparative study has been presented for the most common configurations of the CO2 supercritical single stage refrigeration cycle from energy, exergy, economic and environmental points of view. In order to find out the effects of degree of superheating, using an internal heat exchanger and using an expander instead of expansion valve on the performance of the supercritical CO2 refrigeration cycle, a thermo-economic analysis has been performed. The results show that the increasing of coefficient of performance of the cycle with dual expansion process is not considerable. Also, the use of an internal heat exchanger in a cycle by an expander is not beneficial. Moreover, using expander in basic cycle leads to an increase of 27.3 % in thermodynamic performance and a decrease of 16.1% in total cost rate. This cycle has the lowest penalty cost due to emission of CO2.