Tendency study of heat pump phase change heat storage defrosting technology based on patent bibliometric analysis

The problem of frosting restricts the application and development of air-source heat pumps. Based on the patent bibliometric analysis, taking the phase change heat storage defrosting technology with good energy-saving performance in the heat pump field as the theme, this paper systematically reviews the global patent applications from 2001 to 2022, and analyses the application trend, applicant distribution, applicant countries, foreign applicants’ applications in China, technical efficacy, and technological evolution. GREE, Midea and Matsushita Electric are the main applicants. This field mainly includes five technical branches, i.e. single refrigerant pipeline in the heat storage device, multiple refrigerant pipelines in the heat storage device, recovery of compressor waste heat by the heat storage device, recovery of solar energy by the heat storage device, and structural design of the heat storage device. In order to ensure indoor comfort, technology research and development focuses on realizing heating during heat pump defrosting. The technology of heat storage device recovering compressor waste heat can be distinguished from Matsushita Electric in terms of phase change materials and technical effects.