CO_2-NH_3低温复叠式制冷循环的热力学分析与比较

The thermodynamic analysis and comparison on low temperature CO2 - NH3 cascade refrigeration cycle

本文介绍了一种用于低温环境的采用自然工质CO2-NH3的复叠式制冷循环,介绍和分析了CO2和NH3的物性特征,并且进行了该复叠式制冷循环的热力学理论分析,通过计算得出了不同蒸发温度下的最佳低温循环的冷凝温度和最佳流量比。通过与R13-R22和NH3-NH3复叠式循环的比较,可以看出CO2-NH3的复叠式制冷循环在低温制冷条件下有明显优势。

This paper focuses on the cascade refrigeration cycle using the nature refrigerant CO2 - NH3.The properties of the refrigerants CO2 and NH3 are introduced and analyzed, the thermodynamic analysis on this cascade refrigeration system are privided,the optimum condensation temperature of the low temperature cycle part and the optimum flow ratio are calculated. By comparing with the R13 - R22 and NH3 - NH3 cascade refrigeration cycles, the obvious advantage of the CO2-NH3 cascade refrigeration cycle,at low temperature is demonstrated.