【作者】 赖艳华； 邵长波； 吕明新； 董震； 王庆为；

【Author】 Lai Yanhua~1 Shao Changbo~2 LuMingxin~1 Dong Zhen~1 Wang Qingwei~1 (1.School of Energy and Power Engineering,Shandong University,Jinan 250061; 2.Shandong Institute of Commerce and Technology,Jinan 250103)

【机构】 山东大学能源与动力工程学院； 山东商业职业技术学院；

【摘要】 本文针对所建立的新型R404A/CO₂复叠式制冷设备进行了理论研究,该系统可提供零下40℃以下的低温环境。根据R404A和CO₂的物性特征及复叠式循环流程,通过数值模拟寻找一定工况下CO₂低温级的最佳冷凝温度及二者的最佳质量流量比,分析冷凝蒸发器的工作温度、CO₂侧蒸发温度、R404侧的冷凝温度等对R404A/CO₂复叠式系统COP的影响。结果表明,为了提高循环效率并保证循环的安全运行,应尽可能地升高低温段蒸发温度、降低高温段冷凝温度,缩小冷凝蒸发器的传热温差,环保工质R404A和CO₂的复叠式制冷系统在低温制冷条件下有良好的发展前景。更多还原

【Abstract】 A R404A/CO₂ cascaded refrigeration equipment has been established,which can provide low er than -40℃temperatures.Based on physical properties of R404A and CO₂ and cascaded refrgeration cycle,through simulation and theoretical analysis,an optimum mass flow rate ratio and an optimum condensation temperature of low temperature cycle part are acquired at a definite evaporation temperature and temperature difference of condenser-evaporator heat exchanger.Results show that increasing evaporation temperature of low temperature cycle,decreasing condensation teanperature of R404A,and reducing the temperature difference in cascade heat exchanger are better way to improve COP of this system,at the same time ensuring the operation safety.It can be concluded that R404A/CO₂ environmentally-friendly refrigerants cascaded refrigeration cycle has a good future.更多还原