Performance analyses of CO2-N2O cascade system for cooling

Abstract

The excess usage of many refrigerants which includes chlorofluorocarbons (CFC) and hydro chlorofluorocarbons (HCFC) in cooling systems causes several environmental issues such as acid rain, stratospheric ozone depletion and global climate change. Therefore, the usage of these refrigerants is restricted. In this context, an increase occurs in the usage of the alternative refrigerants. In this study, a cascade system for cooling with N2O as the high temperature fluid and CO2 as the low temperature fluid is theoretical analyzed. Thermodynamic analysis of cooling system as evaporator temperature variations and pumps inlet pressure variations are investigated. Also, the effects of operating parameters on system performance are studied and illustrated in tables. The system of performance of cooling (COP) and exergy efficiency values are found to be 1.99 % and 31.11 % respectively, for condenser 30 °C and evaporator temperature of −25 °C. Also the system of total exergy destruction is calculated 26.16 kW.