三级复叠式制冷系统低温级制冷剂的应用分析

Application analysis of low temperature refrigerant for three stages cascade refrigeration system

中文关键词: 三级复叠式制冷系统 制冷剂 热力学分析 ?分析

英文关键词: three stages cascade refrigeration system  refrigerant  thermodynamic analysis  exergy analysis

中文摘要:

      为研究三级复叠制冷系统中低温循环制冷剂替代的可行性方案，采用R1150/R170/R717、R50/R170/R717和R14/R170/R717三种工质组合，对三级复叠式制冷系统的高低温循环压缩机的排气温度"T" _"d" 、压缩机输入功率W、系统性能系数COP、热力学完善度ηⅡ、系统的?效率ηχ、?损失χ以及系统中各个部件?损失所占比例δi随蒸发温度Te的变化进行热力学分析。研究结果表明：不同蒸发温度下均存在最佳中间循环冷凝温度，使COP值最大。蒸发温度由-100℃升高到-80℃时，R1150/R170/R717的?损失最小，COP、热力学完善度和?效率最大。R1150/R170/R717的COP由0.60增大到0.82。R1150/R170/R717的COP比R14/R170/R717的COP高3.47%~4.49%。主要的?损失部件是冷凝器。冷凝器的?损失所占比例随蒸发温度的升高而升高。综上所述，推荐在三级复叠式制冷系统中采用R1150/R170/R717制冷剂组合方案，研究结果为三级复叠式制冷系统工质组的选择提供理论依据。

英文摘要:

      The purpose of this paper is to explore the feasibility of substitution of low-temperature circulating refrigerant in the three stages cascade refrigeration system (TCRS). Adopting refrigerant group of R1150/R170/R717, R50/R170/R717 and R14/R170/R717, the change of discharge temperature of compressor of high-temperature cycle, medium-temperature cycle and low-temperature cycle, the input power of the compressor, COP, thermodynamic perfect degree, the exergy loss of the system, exergy efficiency of the system and the proportion of exergy loss of each component in the system with the evaporation temperature has been studied by thermodynamic analysis in TCRS, respectively. The results show that: There is an optimal intermediate cycle condensation temperature that makes the COP value maximum under different evaporation temperatures. when the evaporation temperature Te rises from -100 C to -80 C, using the refrigerant groups of R1150/R170/R717, the exergy loss of the system is minimum, COP, thermodynamic perfect degree and exergy loss of the system is maximum. The COP of R1150/R170/R717 increases from 0.60 to 0.82. R1150/R170/R717''s COP is higher than the COP of R14 / R170 / R717 by 3.47% and 4.49%. The main component of exergy loss is the condenser and the proportion of energy loss of condenser increases with evaporation temperature. In summary, the refrigerant group of R1150/R41/R717 is recommended to using in three cascade refrigeration system. The research results provide a theoretical basis for the selection of refrigerant groups in three cascade refrigeration system.