新型双蒸发制冷系统制冷剂的研究

摘要

The development of flow inside a two-phase ejector was investigated and a thermodynamic model was established by mass,momentum and energy balance.The effects of different refrigerants on the performance of the double evaporation refrigeration system(DERS) were studied.Results show that under the new double evaporation refrigeration system,the evaprotion temperature and condensation temperature are fixed,R152a have a better performance than the other four refrigerants.R143a is better than the other four refrigerants in mass flow rate ratio,compression efficiency of ejector,cooling capacity,the improvement of the coefficient of performance.The evaprotion temperature is fixed,the improvement of the coefficient of performance decreases with the increase of condensation temperature,at condensation temperature 55℃,with R143a as refrigerant,the improvement of the coefficient of performance peaks up to 20％.%研究了喷射器内部流体流动过程,应用质量守恒、动量守恒、能量守恒对两相喷射器建立了热力学模型,分析了不同制冷剂对新型双蒸发制冷系统性能的影响.计算结果表明:新型双蒸发系统中,当蒸发和冷凝温度相同时,R152a的性能系数高于其他4种制冷剂,R143a的喷射系数、喷射器的压缩效率、制冷量和性能系数提高率均高于其他4种制冷剂;当蒸发温度不变时,性能系数提高率随着冷凝温度的升高而降低,冷凝温度为30℃时,制冷剂为R143a,性能系数提高率达20％.