R290／CO_2自然工质低温复叠式制冷循环理论分析  

Theoretical Analysis of R290/CO_2 Natural Refrigerants Cascaded Refrigeration Cycle for Low Temperatures

作　　者：宁静红[1] 马一太[1] 李敏霞[1] 

机构地区：[1]天津大学热能研究所,天津300072

出　　处：《天津大学学报》2006年第4期449-453,共5页Journal of Tianjin University(Science and Technology)

基　　金：国家自然科学基金资助项目(59876028).

摘　　要：介绍了低温环境下采用自然工质R290和CO_2的复叠式制冷循环,分析了R290和CO_2的物性特征,通过对R290／CO_2式制冷循环的理论分析,在一定的蒸发温度和冷凝蒸发器传热温差下,计算出循环存在最优的低温循环冷凝温度和最优质量流量比;为提高循环效率和保证循环的安全运行,应尽可能地升高蒸发温度、降低冷凝温度和减少冷凝蒸发器的传热温差,可以看出R290／CO_2的复叠式制冷循环在低温制冷条件下有很好的发展前景．A cascaded refrigeration cycle is introduced, which uses natural refrigerants of R290 and CO2 for low temperatures. The properties of R290 and CO2 are analyzed. Through theoretical analysis of R290/CO2 natural refrigerants cascaded refrigeration cycle, an optimum mass flow rate ratio and an optimum condensation temperature of low temperature cycle part are calculated at a definite evaporation temperature and heat-transfer temperature difference of condenser-evaporator. For enhancing the efficiency of cycle and ensuring the operation safety, it is necessary to increase evaporation temperature, decrease condensation temperature, and reduce heat-transfer temperature difference of condenser-evaporator. It can be concluded that R290/CO2 natural refrigerants cascaded refrigeration cycle has a good future.

关 键 词：R290/CO2 复叠式制冷循环 效率 质量流量比 

分 类 号：TB615[一般工业技术—制冷工程]