Transcritical R41 single-stage compression heat pump cycle with internal heat exchanger

A theoretical model for the transcritical single-stage compression heat pump cycle with an internal heat exchanger was established, and the performances of the cycles using R41(fluoromethane) and CO₂ were analyzed respectively. The results show that both of them run in the transcritical ones at normal temperature, and the R41 cycle displays better comprehensive performance than that of the CO₂ cycle. Compared with the CO₂ cycle under the specified conditions, the average value of the optimal high side pressure of the R41 cycle decreases by more than 40.6% and the COP increases by over 14.2%, and the second law efficiency increases by 14.3%. Moreover, the greater heating capacity and the lower discharge temperature of the R41 cycle can be obtained. In addition, an idea was put forward to improve the exergy efficiency of system by reducing the temperature difference of gas cooler and the pressure difference of throttling process, and making full use of the cold energy in the evaporator.