回热器对双级压缩和复叠式压缩制冷系统影响的分析

为了研究回热器对双级压缩制冷系统和复叠式压缩制冷系统的影响,以R404A双级压缩制冷系统和R404A/R23复叠式压缩制冷系统为例,通过建立两种制冷系统的热力学模型和(火用)分析法,分析了回热器效率对压缩机排气温度、单位质量制冷量、制冷剂质量流量、系统制热能效比(COP)、系统总(火用)损、系统各部件(火用)损和系统(火用)效率的影响。结果表明,在双级压缩制冷系统中,当回热器效率ε 取0.1～0.9时,系统COP增大4.0%,系统的总(火用)损减少9.6%,而系统(火用)效率增大7.1%;在复叠式压缩制冷系统中,系统COP和系统(火用)效率随高温级回热器效率ε 增大而增大,随低温级回热器效率ε增大而减小,而系统总的(火用)损随高温级回热器效率ε 增大而减小,随低温级回热器效率ε 增大而增大。

Effect of internal heat exchanger on two-stage compression and cascade compression refrigeration system

In order to study the effect of internal heat exchanger on two-stage compression and cascade compression refrigeration system,R404A two-stage compression refrigeration system and R404A/R23 cascade compression refrigeration system were taken as examples. Through exergy analysis and establishment of two kinds of refrigeration systems thermodynamic model,the compressor discharge temperature,cooling capacity per unit mass,refrigerant mass flow,system COP,total system exergy loss and exergy efficiency of the regenerator were analyzed. In the two-stage compression refrigeration system,when thermal efficiency was between 0.1 and 0.9,system COP increased by 4.0%,leading to a reduction in total loss of 9.6 percent exergy system and the system exergy efficiency could increase by 7.1%. In the cascade compression refrigeration system,system COP and exergy efficiency of the system increased with increasing high-temperature regenerator efficiency and decreased with decreasing low-level heat recovery efficiency. The total loss of exergy systems decreased with increasing high temperature level regenerator efficiency and increased with increasing low-level heat recovery efficiency.