跨临界CO_2热泵性能试验及优化分析

Performance test and optimization analysis of transcritical CO_2 heat pump

为进一步研究跨临界CO_2热泵的系统性能,针对所设计CO_2热泵系统进行实验。实验结果表明:在风机频率一定时,系统热负荷、压缩机轴功率、系统出风温度均随压缩机频率的增大而增大。蒸发温度从-2℃升至4℃,COP增幅为26%,CO_2在气冷器出口温度降低10℃左右时,系统COP增幅大于30%。实验工况下跨临界CO_2热泵系统出风温度变化范围在50℃-100℃,在获得大于75℃出风温度时,热力学第二定律效率超过30%,CO_2气冷器出口温度、高压侧压力、蒸发温度的升高都会提高系统热力学第二定律效率。

In order to further study the performance of transcritical CO2 heat pump system, the experiment of system per- formance was carried out for the designed CO2 heat pump system. The experimental results show that when the fan frequency is constant, the system heating capacity, the compressor shaft power and the heated air temperature increase with the increase of the compressor frequency. Evaporation temperature increases from -2 ℃ to 4 ℃, COP increases by 26% ; The outlet temperature of CO2 in the gas cooler decreases by about 10 ℃, the system COP increases by more than 30%. The temperature of the exhaust air of the transeritical CO2 heat pump system under test conditions varies from 50℃ to 100℃. The second law of thermo - dy- namics efficiency exceeds 30% when the temperature of air outlet is more than 75℃. The increase of the CO2 gas cooler outlet temperature, high pressure side pressure and evaporation temperature will increase the efficiency of the second law of thermo - dynamics.