船用自复叠制冷系统与双级压缩制冷系统热力性能对比研究

Comparative Study on Thermal Performance of Marine Self-cascading Refrigeration System and Two-stage Compression Refrigeration System

采用流程模拟计算的方法,研究了新型四元混合制冷剂的自复叠制冷系统与传统制冷剂的双级压缩制冷系统的热力学性能,分析了针对-65℃的目标制冷温区下,两种系统的吸排气压力、系统性能系数(COP)。结果表明:当自复叠制冷系统选择R14/R23/R134a/R245fa(0.35/0.36/0.1/0.19)混合制冷剂时,系统COP可达1.037,排气压力与吸气压力分别为1 590 kPa与740 kPa,压比小于3,并且排气温度仅为61℃,工况参数良好。针对双级压缩制冷系统,通过调节两级压缩的中间压力获得系统运行最佳工况,通过对比发现,自复叠制冷系统的COP比R22制冷系统COP低7.32%,但其COP分别高于R404A及R407C制冷系统27.15%及5%。

The process simulation calculation method is used to study the thermodynamic performance of the self cascading refrigeration system of the mixed refrigerant and the two-stage compression refrigeration system of the traditional refrigerant.The suction and exhaust pressure,system coefficient of performance(COP)and so on of the two systems are analyzed under the target refrigeration temperature zone of-65℃.The results showed that,for the target cooling temperature of-65℃,when R14/R23/R134a/R245fa(0.35/0.36/0.10/0.19)is selected as the mixed refrigerant,the COP could reach 1.037,the suction and exhaust pressure the are 740 kPa and 1590 kPa,the pressure ratio is less than 3,and the exhaust temperature is only 61℃,and the working condition parameters are excellent.By adjusting the intermediate pressure of two-stage compression,the optimal operating condition of the system is obtained.It is found that the COP of the self-cascading refrigeration system is 7.32%lower than that of the traditional R22 refrigeration system,27.15%and 5%higher than that of the R404Aand R407C systems,respectively.