Analysis and Review of Refrigerants Properties for High Temperature Heat Pumps

Research and development efforts have been ongoing to replace fossil fuel-based energy systems with high-temperature heat pumps (HTHPs) in response to environmental challenges like global warming. This study investigates the use of hydrofluoroolefins (HFOs), hydrochlorofluoroolefins (HCFOs), and natural refrigerants in HTHPs operating at temperatures above 130℃. Performance evaluations were conducted based on thermophysical properties. A review of existing literature assessed the thermodynamic properties, ozone depletion potential (ODP), global warming potential (GWP), and safety group (SG) classifications of the candidate refrigerants. The findings suggest that R1336mzz(Z), R1130(E), and R718 are the most suitable refrigerants for operating temperatures above 160℃, while R1130(E) and R718 are the best choices for temperatures exceeding 200℃.