CO_(2)跨临界双级压缩机械过冷循环的性能分析

Performance analysis for mechanical subcooling cycle of CO_(2) transcritical two-stage compression

为了提高CO_(2)跨临界循环的性能,提出了一种双级压缩机械过冷带回热器(简称“TSC+MS+RE”)循环,将其与双级压缩机械过冷(简称“TSC+MS”)循环、双级压缩带回热器(简称“TSC+RE”)循环进行理论计算和性能比较,分析了蒸发温度、环境温度、过冷度、制冷剂流量和排气压力等参数的影响。结果表明:TSC+MS+RE循环的性能最好;在最佳过冷度下,TSC+MS+RE循环的COP比TSC+RE循环增加了33.3%,比TSC+MS循环增加了10.9%;TSC+MS+RE循环的最佳过冷度随着蒸发温度的升高而减小,压缩机耗功比随着蒸发温度的升高而逐渐增大;对于TSC+MS+RE循环,增设回热器导致了压缩机排气温度的升高。

In order to improve the performance of CO_(2) transcritical cycle,a new cycle of two-stage compression mechanical subcooling with internal heat exchanger was proposed.Its performance was calculated theoretically and was compared with twostage compression mechanical subcooling(TSC+MS)cycle and two-stage compression with internal heat exchanger(TSC+RE)cycle.In addition,the influences of evaporation temperature,ambient temperature,subcooling temperature,refrigerant mass flow rate and discharge pressure and so on were analyzed.The results show that the performance of TSC+MS+RE cycle is the best;the COP of TSC+MS+RE cycle was increased by 33.3% and 10.9% respectively compared with TSC+RE and TSC+MS cycle under the optimal subcooling temperature;The optimal subcooling temperature of TSC+MS+RE cycle decreases with the increase of evaporation temperature.The power consumption ratio of compressor rises gradually with the increase of evaporation temperature;For TSC+MS+RE cycle,the addition of internal heat exchanger results in the increase of compressor discharge temperature.