带回热器的R1234yf热泵系统能量分析和分析

Energy and exergy analysis of R1234yf heat pump system with internal heat exchanger

蒸汽压缩式系统引入回热器,可有效提高系统性能。与R134a相比,制冷剂R1234yf具有较低温室效应潜值,其环保效应更加明显。针对R1234yf热泵系统建立能量平衡方程和平衡方程,分析了蒸发温度、冷凝温度和过热度对系统性能系数COP、制热量、排气温度和系统效率的影响,并与R134a系统对比。结果表明:R134a系统COP和制热量比R1234yf系统分别高1.39%—4.06%和0.53%—4.08%,系统效率比R1234yf热泵系统高2.03%—3.27%。随过热度的提高,两系统COP和效率的差值不断减小。

The introduction of internal heat exchanger can improve system perfomance in vapor compression system. Compared with R134a, refrigerant R1234yf has a lower global warming potential, and its environmental effect is more obvious. The energy balance equation and the exergy balance equation were established for R1234yf heat pump system. The effects of evaporation temperature, condensation temperature and superheat degree on the system coefficient of perfomance COP, heating capacity, exhaust temperature and system efficiency were analyzed and compared with R134a system. The t^sults show that the performance of the two systems is similar, but the COP and the heating capacity of the R134a system are 1.39%-4.06% and 0. 53%-4. 08% higher than that of the R1234yf heat pump system, respectively, and the system efficiency is 2.03%-3.27% higher than that of the R1234yf heat pump system. As the degree of superheat increases, the difference between the COP and the efficiency of the two systems are reducing.