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摘 要： 设计了典型的CO2- NH3复叠式制冷流程和NH3两级压缩制冷流程，对流程进行了模拟计算，比较了两者的关键参数，并分析了换热器的热流分布及氨系统的参数优化。结果表明：在蒸发温度-45℃的条件下，复叠式系统的压缩机总功耗、制冷剂NH3流量小于氨系统，但氨系统具有较大规模的中温制冷量，其总制冷系数COP大于复叠式系统。复叠式系统冷凝蒸发器的两相流间换热温差较小，而氨系统中间冷却器的换热温差较大。随着高压级排气压力的上升，以及中间温度的降低，氨两级压缩机的总功耗呈下降趋势。 关键词 ：CO2- NH3；复叠；NH3；制冷系统；流程参数 Parameters Comparison Of Processes Between Co2-Nh3 Cascade And Nh3 Refrigeration Systems Cao Wensheng1 Lu Xuesheng2 (1 Mechanical Engineering College of Jimei University, Xiamen 361021, Fujian, China; 2 Institute of Refrigeration and Cryogenics of Shanghai Jiao Tong University, Shanghai 200240, China) Abstract： Two typical types of CO2- NH3 cascade and NH3 two stage compression refrigeration processes were designed and calculated. The key parameters of the two processes were compared, and the heat flow distributions of heat exchangers were also analyzed, as well as parameters optimization of the NH3 refrigeration system. The results show that in terms of evaporation temperature at -45℃, the total power consumption of compressors and NH3 flow of the CO2- NH3 cascade process are less than that of the NH3 process. But there is massive refrigeration capacity at medium temperature in NH3 process, so the COP of NH3 process is higher than of CO2- NH3 process. The difference in temperature of two phase liquids in the condensation-evaporator of cascade system is less, and that in the midst cooler of NH3 system is larger. Along with the ascending exhaust pressure of high-pressure stage compressor and the descending midst temperature, the total power consumption of the NH3 process of two stage compression will be downtrend. Key words: CO2- NH3 cascade NH3 refrigeration system process parameter