制冷工质对原料奶速冷系统的冷却效率起着重要的作用,因此,需要深入地研究不同的制冷工质对系统的影响.通过利用Helmholtz自由能状态方程,模拟仿真得到原料奶速冷系统制冷性能系数(COP).再结合制冷工质的安全性和环保性要求,对比分析6种纯工质的优缺点.结果表明,R22是综合性能表现最佳的制冷工质.针对使用纯工质的原料奶速冷系统存在传热温差过大的问题,可以通过利用非共沸工质温度滑移的特性,有望在某种程度克服这些问题,进而改善原料奶速冷系统的能源效率.%Refrigerants plays an important role in the efficiency of rapid cooling systems of raw milk. Therefore,it is necessary to study the impact of different refrigerants on the performance of milk-cooling systems. By using Helmholtz free energy equations of state,this work simulates the coefficient of performance(COP)of raw milk rapid cooling systems using six refrigerants. The six refrigerants are compared according to COP and safety and environmental requirements. The results show that among these refrigerants R22 could be the best choice in terms of the overall performance. Since the rapid cooling systems using pure refrigerants have the problem with large heat transfer temperature difference,we infer that zeotropic refrigerants having temperature glides can alleviate the problem in some extent and improve the energy effi-ciency of raw milk rapid cooling systems.
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