带回热器的跨临界CO2空气源热泵系统性能实验研究

Experimental Study on Performance of Transcritical CO2 Air-Source Heat Pump System With Regenerator

本文对带回热的跨临界CO2空气源热泵循环在不同压缩机频率下运行时的特性进行了热力性能分析。结果表明:在25 Hz和30 Hz压缩机频率下,系统COPh随排气压力的升高都存在峰值。在35 Hz压缩机频率下,由于受限于系统高温保护,系统COPh随排气压力的升高逐渐增大,从趋势来看也存在峰值。压缩机频率升高,出水温度、气冷器出口温度和排气温度都升高,CO2质量流量增加,系统COPh减小。与25 Hz和35 Hz压缩机频率下的系统性能相比,30 Hz压缩机频率下的系统运行性能更优,系统最大COPh为3.88,对应的最优排气压力为9.2 MPa,对应的最高出水温度为91.1℃。

This paper presents an analysis on the thermal performance of the transcritical CO2 air-source heat pump cycle with regenerator at different compressor frequencies.The results show that the system COPhhas a peak value with the increase of discharge pressure at the compressor frequency of 25 Hz and 30 Hz.Due to the high temperature protection of the system,the system COPh increases with the increase of discharge pressure at the compressor frequency of 35 Hz.However,there is always a peak value based on the trend.With the increase of the compressor frequency,the pressure ratio increases,the water outlet temperature,the CO2 gas cooler outlet temperature and the discharge temperature all raise,the CO2 mass flow increases,and the system COPh reduces.The system performance shows better at the compressor frequency of 30 Hz than that at the compressor frequency of 25 Hz and 35 Hz,respectively,where the maximum COPh is 3.88,the corresponding optimal discharge pressure is 9.2 MPa,and the corresponding highest water outlet temperature is 91.1℃.