CO2及CO2/R41跨临界单/双级循环系统的热力学性能对比研究OA

In order to improve the comprehensive performance of the CO2 transcritical heat pump water heater system,thermodynamic models of single-stage and two-stage cycles adopting pure CO₂ and CO₂/R41 azeotropic mixture as working fluids are established.Based on energy and exergy analysis methods,the comprehensive performance of the four cycle systems is calculated and comparatively analyzed.The results show that the two-stage cycle can effectively reduce the compressor discharge temperature(a maximum reduction of 61.79℃)and power consumption,accompanied by a partial decline in exergy efficiency.The CO ₂/R41 mixed working fluid dramatically decreases the optimal high pressure(a maximum reduction of 20.96%)and increases the specific heating capacity(a maximum increment of 19.68%),while raising the specific power consumption of the compressor.The addition of R41 exerts a slight influence on the irreversible loss ratio of each component in the CO₂ transcritical cycle.Among the four cycle systems,the capillary tube presents relatively high irreversible loss.The CO₂/R41 two-stage cycle system achieves the highest COP and superior specific heating capacity,as well as a relatively low discharge temperature and operating pressure.This study can provide theoretical support for the engineering application and performance optimization of CO₂/R41 mixed working fluids in two-stage transcritical heat pump systems.