DME或R600a与角鲨烷为工质对的吸收式制冷循环性能分析

Performance Analysis of Absorption Refrigeration Cycles Using DME or R600a and Squalane as Working Pair

本文分析了R600a/角鲨烷和DME/角鲨烷工质对在单效和压缩辅助吸收式制冷循环中的热力学性能。利用NRTL模型关联了两种工质对的汽液相平衡数据,分析了发生温度、蒸发温度和压缩机压比对循环性能系数(COP)、[火用]效率和循环倍率的影响。结果表明:R600a工质对的性能更优。相比于单效循环,压缩辅助循环性能明显更高。在蒸发温度为278.15 K时,两种循环的COP和[火用]效率均随发生温度升高存在峰值;在发生温度为363.15 K时,两工质对的COP随蒸发温度的升高而单调增加,而[火用]效率存在峰值。随发生温度和蒸发温度的升高,R600a和DME工质对的COP最高可达0.675和0.655。DME工质对的性能随压缩机压比的增加不断增大,而R600a工质对在压比为1.5时性能最优。随着发生温度、蒸发温度和压比的升高,循环倍率不断减小。

The thermodynamic performance of R600a/squalane and DME/squalane working pairs in single-effect and compression-assisted absorption refrigeration systems was analyzed in this study.The vapor-liquid equilibrium data were correlated using the NRTL model.The effects of the generation temperature,evaporation temperature,and compressor pressure ratio on the COP,exergy efficiency,and circulation ratio were analyzed.The results show that the R600a/squalane working pair performed better.The performance of the compression-assisted cycle was significantly better than that of the single-effect cycle.At an evaporation temperature of 278.15 K,peaks occur in the COP and exergy efficiency curves for single-effect and compression-assisted cycles with the increase in evaporation temperature.At a generation temperature of 363.15 K,the COP of the two working pairs increases monotonously with the increase in evaporation temperature,and the exergy efficiency curves exhibit peaks.With increasing generation and evaporation temperatures,the maximum COP and exergy efficiency values for the R600a and DME working pairs in the two cycles were 0.675 and 0.655,respectively.The performance of the DME working pair increased with an increase in the compression ratio,whereas that of the R600a working pair peaked at a ratio of 1.5.The circulation ratio decreased as the generation temperature,evaporation temperature,and pressure ratio increased.