Analysis of the First and Second Laws of Engine-Driven Heat Pumps Using Low GWP Refrigerant

The applicability of alternative refrigerants in GHP can be accurately decided by considering not only the thermodynamic efficiency of the GHP using the alternative refrigerant, but also the exergy loss.In this study, energy and exergy analyses were performed to evaluate the performance and performance improvement potential of GHP using a low-GWP refrigerant.The state of refrigerant at the inlet and outlet of the main components was calculated, and the exergy loss, exergy efficiency, and improvement potential of the main component of GHP using an alternative refrigerant were calculated using the calculation results.Exergy loss was lowest in GHP using R32, followed by those using R410A, R466A, R290, and R452B.The highest exergy loss was shown in the condenser, followed by the compressor, evaporator, and expansion device.Compared to R410A, the exergy loss in the compressor, condenser, evaporator, and expansion valve of GHP using R32 was 6.9%, 9.3%, 8.0%, and 0.5% lower than that using R410A, respectively.In addition, the exergy efficiency was in the reverse order of the exergy loss, and the improvement potential was in the same order as the exergy loss.The GHP using R452B showed the highest improvement potential; the improvement potential in the compressor, condenser, evaporator, and expansion valve was 4.1%, 8.7%, 6.3%, and 0.2% higher than that using R410A, respectively.These results confirm the suitability of R32 as an alternative refrigerant to R410.Furthermore, R452B would also be a suitable alternative refrigerant to R410A with a decrease in exergy loss.