Experimental Study on the Heating and Cooling Performance of a Vapor Injection Heat Pump Using Low-GWP Refrigerants

Abstract

Heat pumps have been used in buildings owing to their high energy efficiency and low carbon dioxide emissions. However, the performance degradation of heat pumps is inevitable under severe weather conditions. In recent years, the refrigerant injection technique has been extensively investigated to mitigate this problem. Among various injection cycles, the vapor injection cycle (VIC) is one of the most popular types and is widely used due to its simple control. Heo et al. [1] investigated the performance of a flash tank VIC at low temperatures. The coefficient of performance (COP) and heating capacity of the heat pump increased by 10% and 25%, respectively, at -15 ℃ . Qin et al. [2] tested an internal heat exchanger VIC for electric vehicles at -20 ℃. It was found that the heating capacity increas ed up to 31% compared to that of the conventional cycle. restrict the of warming Therefore, which is