采用非共沸混合工质的原奶速冷式系统热力学仿真与性能分析

Thermodynamic simulation and performance analysis on rapid raw milk cooling system using non-azeotropic mixture

通过利用Helmholtz自由能状态方程,模拟计算6种非共沸混合工质的原奶速冷式系统制冷性能系数(COP),并与纯工质作比较,分析非共沸混合工质的优缺点。结果表明,非共沸混合工质的原奶速冷式系统COP普遍大于采用纯工质的原奶速冷式系统COP,R436A是6种混合工质中综合性能最好的。尽管采用非共沸混合工质可以有效地改善原奶速冷式系统传热温差过大的问题,但原奶速冷式系统的传热温差仍旧偏大。指出在将来的研究中若采用组合式原奶速冷式系统,可在某种程度克服这些问题,进而改善原奶速冷式系统的能源效率。

By using state equetions of Helmholtz free energy, the coefficient of per-formance （COP） of rapid raw milk cooling system using six kinds of non-azeotropic mix-ture is simulated. Compared with pure refrigerant, the advantages and disadvantages of non-azeotropic mixture are analyzed. The results show that the COP of rapid raw milk cooling system with non-azeotropic mixture is generally greater than that of pure refriger-ant. In the six kinds of mixture？ R436A has the best comprehensive properties. Although the non-azeotropic mixture can effectively improve the issue of overlarge temperature drop of transfer heat in rapid raw milk cooling system, the value is still large. It is pointed out that the combined rapid raw milk cooling system can overcome these issues in a certain de-gree 9 and improve the energy efficiency of rapid raw milk cooling system.