R22与其替代工质的性能比较与分析

1前言传统的单工质蒸气压缩理论循环分析认为在冷凝器和蒸发器中,制冷剂的冷凝温度和蒸发温度等于相变温度,而忽略了压缩机进出口的过热段以及冷凝器出口过冷段的温度变化,直接造成了人们对回热循环和过热循环的认识偏差,产生了许多误解,其评价标准是有缺陷的。本文以变温热源的可逆循环为基础,考虑了在实际中是可以利用的过热段以及过冷段的温度变化,假设在冷凝器和蒸发器中,制冷剂与外界高、低温热源无换热温差,使循环更接近可逆循环。以此为基础的当量温度法可完善单工质的理论循环分析,同时可用于朗肯循环与劳伦兹循环之间的…

THE PERFORMANCE COMMRISON OF R22AND ITS ALTERNATIVES

This paper uses the concept of "equivalent temperature" and presents a new standard used to evaluate vapor compression cycle. The evaluation standard eliminates the error of superheat temperature, and builds the relation of Rankine cycle and Lorenz cycle. Based on the standard, the paper compares cycle performance of R22 and its alternatives including pure refrigerants and mixtures. Refrigerant thermodynamic properties are calculated by using the Carnahan-Starling-DeSantis equation of state. The results indicate that intracycle can improve COP of all refrigerants. Intracycle reduces the volumetric refrigeration capacity of R22, R32 and R717(NH3), but all mixture alternatives can be improved.