三级复叠式制冷系统回热优化仿真研究

Simulation Study on Optimization of Heat Rejection in Three-Stage Cascade Refrigeration System

通过建立热力学模型,结合MATLAB软件,对回热优化效果进行仿真研究。研究分析了回热器对压缩机排气温度、压缩机单位质量制冷量和制冷剂质量流量以及系统COP的影响。实验结果显示,随着回热器效率ε在0.1~0.9范围内逐渐增大,高、低温两级压缩机的排气温度逐渐升高,单位质量制冷量qe逐渐增大,而制冷剂质量流量却逐渐减小。此外,系统的COP随低温级回热器效率的增大而减小,随高温级回热器效率的增大而增大。所得结果具有一定的参考价值,可为三级复叠制冷系统的优化研究提供依据。

In this paper,using the natural working medium combination R717/R170/R1150 as refrigerant,we design the three-stage stacked refrigeration system,and optimize its high temperature and low temperature stage.The thermodynamic model was combined with MATLAB software.The effects of reheater on compressor exhaust temperature,compressor unit mass and refrigerant mass flow and system COP are analyzed.The experimental results show that with the gradual increase of the efficiency of the reheaterεin the range of 0.1~0.9,the exhaust temperature of the high and low temperature compressor gradually increases,and the cooling capacity per unit mass qe gradually increases,while the mass flow of refrigerant gradually decreases.Moreover,the COP of the system decreases with the increasing efficiency of the low-temperature stage reheater.The results have certain reference value and can provide a basis for the optimization of tertiary cascade refrigeration system.