一种新型机械过冷喷射制冷系统的理论研究

提出了一种新型机械过冷喷射制冷系统(NERS).该循环系统引入了一个辅助的液体-气体射流泵,通过消耗少量泵功,对冷凝器出来的液体进行过冷.与常规喷射制冷系统(CERS)相比,该系统可以有较大的过冷度.建立了新系统的数学模型,并针对环保制冷剂R600a和R152a两种工质进行了模拟计算.重点分析了发生器温度和机械过冷度对新循环性能的影响,并与常规喷射制冷循环进行了性能比较.计算结果表明,新循环能有效提高系统的性能系数(COP).对于制冷剂R600a和R152a,新循环COP比常规循环可分别提高约12%和11%.尽管新循环消耗的泵功稍有增加,但从火用的角度分析,新循环可以节约7%~8%的输入火用.对一定的制冷剂和工况,有相应的最佳机械过冷度存在.

Theoretical study on a new mechanical subcooling ejector refrigeration system

A new mechanical subcooling ejector refrigeration system(NERS)is proposed.An additional jet-pump(liquid-gas ejector)was used to subcool the refrigerant from condenser in this new system.Compared with a conventional ejector refrigeration system(CERS),the NERS has larger subcooling degree.A mathematical model was developed and simulation calculation was carried out for environment-friendly refrigerants R600a and R152a.The effect of generator temperature and mechanical subcooling degree on the performance of the NERS was mainly discussed,and the performance of the NERS was compared with that of the CERS.Results of simulation show that the NERS can efficiently improve the coefficient of performance(COP).COP can be improved about 12% for R600a and about 11% for R152a.Though slightly more pump work is consumed in NERS,from view of exergy,the NERS can save 7%-8% input exergy.The analysis indicates that an optimum mechanical subcooling degree should exist for a refrigerant and operating condition.