From common low temperature to ultra-low temperature: overview of frosting characteristics and defrosting techniques in equipment

With the rapid advancement of low-temperature refrigeration technology, its applications have expanded beyond conventional low-temperature civilian equipment to include large-scale industrial equipment in the field of ultra-low temperatures. The operation of cryogenic equipment inherently involves heat exchange with the surrounding environment. In low-temperature, high-humidity conditions, the surfaces of heat exchangers in such equipment are highly susceptible to frosting. Frost accumulation increases thermal resistance, significantly reducing energy efficiency and causing substantial power wastage. The frosting rates of cryogenic equipment vary due to differences in operating conditions across devices. This review systematically examines recent advancements in frosting characteristics, influencing factors, and anti-frosting and defrosting technologies across various equipment and operating environments. Identifying and implementing suitable anti-frosting and defrosting strategies for specific conditions can significantly improve equipment performance and efficiency. This article categorizes temperature into three zones: common low temperature, transitional low temperature, and ultra-low temperature. It provides a detailed analysis of the frosting characteristics of representative equipment in each zone. Based on the research findings, targeted anti-frosting and defrosting strategies are proposed to optimize the maintenance and management of low-temperature refrigeration equipment. The insights presented serve as a valuable reference for researchers, manufacturers, and designers aiming to enhance equipment performance.