Vapor compression heat pumps with pure Low-GWP refrigerants

Abstract

Global warming is a major environmental concern, which significantly impacts ecological systems and the safety of coastal cities. To address global warming, effective methods must be adopted to reduce greenhouse gas emissions and the consumption of fossil fuels. Vapor compression heat pumps offer an effective way to recover energy from waste heat sources and reduce primary energy consumption. However, the traditional working fluids used in heat pumps generally have a high global warming potential (GWP) and produce a significant greenhouse effect when leaked. Therefore, low-GWP (GWP<150) refrigerants have recently become a topic of widespread research interest for the continuing development of vapor compression heat pumps. Much research has examined the performance, characteristics, and application potential of low-GWP refrigerants in heat pumps. However, no published reviews have exclusively focused on the status of research on heat pumps with pure low-GWP refrigerants and no systematic application guidelines have been developed for these low-GWP vapor compression heat pumps. This review analyzes the use of 17 different pure low-GWP refrigerants, including natural refrigerants (R717, R718, and R744), hydrocarbons (R290, R600, R600a, R601, and R1270), hydrofluorocarbons (R152a and R161), hydrofluoroolefins (R1234yf, R1234ze(E), R1234ze(Z), R1336mzz(Z), and R1336mzz(E)), and hydrochlorofluorolefins (R1233zd(E) and R1224yd(Z)), for use in vapor compression heat pumps. Guidelines for the application of these heat pumps are also presented based on a review of the existing literature and a thorough comparison of simulation studies on heat pumps using pure low-GWP refrigerants.