三种CO2跨临界制冷循环热力分析

Thermal analysis of three CO2 trans-critical refrigeration cycles

通过建立热力学模型,对三种不同的CO2跨临界制冷循环进行研究,系统地分析了排气压力、气冷器出口温度、蒸发温度等参数对循环系统性能的影响。研究结果表明:三种循环的COP都随排气压力升高先增后减,随气冷器出口温度升高而减小,随蒸发温度升高而增大;通过单级压缩循环与两级压缩循环的COP对比,可以发现相同条件下,CO2两级压缩循环的COP比单级压缩循环高;对两种两级压缩循环进行对比,可以发现带闪蒸器的制冷循环系统的COP高于带中冷器的制冷循环系统的COP。

In this paper,three different CO2 trans-critical refrigeration cycles were studied by establishing a thermodynamic model.The effects of parameters such as exhaust pressure,air cooler outlet temperature and evaporation temperature on the cycle performance were systematically analyzed.The results show that the COP of the three cycles increases first and then decreases with the increase of exhaust pressure,decreases with the increase of the outlet temperature of the air cooler,and increases with the increase of evaporation temperature;through the single-stage compression cycle and the two-stage compression cycle compared with the COP,it can be found that the COP of the CO2 two-stage compression cycle is higher than the single-stage compression cycle under the same conditions.Comparing the two twostage compression cycles,it can be found that the COP of the refrigeration cycle system with the flasher is higher than the COP of the refrigeration cycle system with the intercooler.