超市展示柜中应用R404A/R744复叠制冷系统的理论分析  

Theoretic analysis on application of R404A/R744 cascade refrigeration system in display case in supermarket

作　　者：冯明坤[1] 曹小林[1] 潘雯[1] 陈惠[1] 杨思思[1] 

机构地区：[1]中南大学能源科学与工程学院,长沙410083

出　　处：《制冷与空调（四川）》2008年第5期31-34,共4页Refrigeration and Air Conditioning

摘　　要：提出了一种可以应用于超市展示柜中的R404A/R744复叠制冷系统,该系统以R404A作为高温级制冷剂,以R744作为低温及制冷剂。并通过对该系统和R22制冷系统进行热力学性能和压缩机输气系数的计算和比较。研究表明:在蒸发温度和冷凝温度固定的情况下,存在一个最佳中间温度使系统的性能系数最大;R404A/R744复叠制冷系统的性能系数和R22制冷系统基本相当,而复叠系统的压缩机输气系数明显高于单级制冷系统。A cascade refrigeration system, in which R404A is used as the refiigerant in the high-temperature stage and R744 is used as the refrigerant in the low-temperature stage, is introduced in this paper. The thermodynamic performance and volumetric efficiency of compressor in both this cascade refrigeration system and a single stage R22 refrigeration system are analyzed. It is shown that there exists an optimum mean temperature in evaporator-condenser to maximize the COP of the system, it is also shown that the volumetric efficiency of compressor in cascade refrigeration system is much higher than that in single stage refrigeration system.

关 键 词：R744 复叠制冷系统 输气系数 

分 类 号：TB6[一般工业技术—制冷工程]