Performance of Heat Pump Air Conditioning with R1234ze (HFO) as a Refrigerant

Abstract

The study shows that refrigerants R1234ze (E) and R1234ze (Z), known for their low global warming potential, are likely to become primary choices in heat pump air conditioning for residential and commercial use. The research evaluates the thermodynamic properties of R1234ze (Z) using experimental, thermodynamic, and numerical analyses. It addresses F-gas regulation requirements and aligns with the Paris Agreement goals by exploring various refrigerants, including R227ea, R114, R236fa, R134a, R1234ze (Z), and R245fa, as potential candidates for evolving industry needs. The analysis indicates that R1234ze (Z) outperforms other working fluids in heat pump applications, with an optimized theoretical coefficient of performance (COP) at a condensation temperature 22 K lower than critical temperatures. However, actual COP deviates due to a significant pressure drop, especially with inadequate volumetric capacity. A key finding is that a substantial portion of the pressure reduction is attributed to mitigating irreversible losses, estimated at a condensation temperature of 70–75°C, emphasizing the complex relationship between pressure and performance. The study suggests that R1234ze (Z) is more suitable for high-temperature applications than traditional air conditioning systems. In a parallel assessment, the initial calculation of the coefficient of performance for R245fa evaluates the reliability of a new refrigeration industry arrangement. Test results for heat pump technology reveal that R1234ze (Z) achieves an impressive COP of up to 3.60 at a buildup temperature of 90°C with a temperature differential of 45 K. This positions R1234ze (Z) as a suitable choice for heat pump applications prioritizing simplicity in system design.