Thermodynamic Analysis of an NH3/CO2 Cascade Refrigeration System with Subcooling in the Low-Temperature Circuit Utilizing the Expansion Work

NH3/CO2 cascade refrigeration system is recognized one of the most promising technologies in low-temperature application. In this paper, a with subcooling circuit driven by recovery expansion work has been proposed. The aim study to investigate proposed compared conventional system. Mathematical models based on energy conservation and exergy balance are established. selection different refrigerants auxiliary discussed. effects operating parameters such as condensation temperature circuit, evaporation temperature, expander efficiency performance evaluated. results show that coefficient about 7.56% 7.98% higher than discharge NH3 compressor can be significantly reduced 18.33%. isentropic large impact performance.