三级自复叠制冷系统模拟研究

Simulation Study of Three-Stage Auto-Cascade Refrigeration System

摘要: 以采用R236fa/R23/R14非共沸混合工质为制冷剂的三级自复叠制冷装置为分析对象，借助模拟软件实现对参数的精准控制，分析不同工况下的模拟结果，比较制冷系统的吸排气温度、压缩机功耗、系统制冷量和性能系数，研究不同工况对制冷系统性能的影响规律。结果表明，在组分配比相同时，增加混合工质质量流量能够增加系统制冷量，但是压缩机耗功增加更为显著，导致系统性能系数下降；降低冷凝器出口温度，有助于改善压缩机运行工况，提高系统整体性能；进入蒸发器制冷的并不是纯净的R14，冷凝温度过低会减小进入蒸发器的工质流量，降低系统制冷量；在工质流量相同时，增加低沸点组分比例可以增加系统制冷量，获得更低的制冷温度，但会增大压缩机功耗，系统性能系数下降。研究结果为制冷装置的改进和优化提供了参考。

Abstract: A three-stage auto-cascade refrigeration device using R236fa/R23/R14 non-azeotropic mixture as refrigerant is taken as the analysis object. The simulation software is used to realize the accurate control of the parameters, and the simulation results under different working conditions are analyzed. The suction and discharge temperature, compressor power consumption, system cooling capacity and coefficient of performance of the refrigeration system are compared, and the influence of different working conditions on the performance of the refrigeration system is studied. The results show that increasing the mass flow rate of the mixed refrigerant can increase the cooling capacity of the system, but the power consumption of the compressor increases more significantly, resulting in a decrease in the coefficient of performance of the system. Reducing the outlet temperature of the condenser helps to improve the operating conditions of the compressor and improve the overall performance of the system. It is not pure R14 that enters the evaporator for refrigeration. If the condensation temperature is too low, the flow rate of the working fluid entering the evaporator will be reduced and the cooling capacity of the system will be reduced. When the flow rate of the working fluid is the same, increasing the proportion of low boiling point components can increase the cooling capacity of the system and obtain lower cooling temperature, but it will increase the power consumption of the compressor and decrease the coefficient of performance of the system. The research results provide a reference for the improvement and optimization of the refrigeration device.