跨临界CO_2双级压缩制冷循环的热力学分析与比较

Thermodynamic Analysis and Comparison of Transcritical CO_2 Two-stage Compression Refrigeration Cycles

对带中间冷却器的双级压缩制冷(TCEI)循环和带闪发器的双级压缩制冷(TCFI)循环进行了热力学分析与比较。结果表明:TCFI循环的最佳中间压力和最佳排气压力低于TCEI循环。在常规空调工况下,TCFI循环的COP高于TCEI循环。在蒸发温度从-10℃变化到10℃时,TCFI循环和TCEI循环的COP相对基本循环平均提高幅度分别为32.3%和18.7%。

The thermodynamic analysis and comparison of two-stage compression cycle with external intercooler （TCEI） and two-stage compression cycle with flash intercooler （TCFI） is presented. The results show that the optimum intermediate pressure and the optimum gas cooler pressure of the TCFI cycle are lower than that of the TCEI cycle. The cycle COP of the TCFI is higher than that of the TCEI cycle in the normal condition of air conditioning systems. The optimum COP of TCFI cycle and TCEI cycle shows averagely 32.3% and 18.7% improvement over that of the base cycle respectively when the evaporating temperature varies from-lO ℃ to 10 ℃.