Research progress of direct contact heat storage based on phase change heat storage

Abstract

Phase change heat storage presents a promising solution to address challenges related to new energy intermittency and waste heat recovery. However, for it to function as an effective energy hub, heat storage becomes crucial. Among the available options, the direct contact heat accumulator stands out due to its simple structure, substantial heat transfer area, and minimal heat transfer resistance, making it a favorable choice for enhancing energy storage rates. Although a great deal of research has been done on phase change materials and heat accumulators over the years, a systematic review of direct‐contact heat accumulators is lacking. This article reviews the related research on direct contact heat storage, aiming to summarize the research work on direct contact phase change heat storage systems. Various phase change materials (PCMs) for direct contact systems are analyzed, and the study of PCM melting crystallization behavior, heat transfer coefficients and system performance in direct contact systems is summarized, as well as the improvement methods for direct contact vessels and PCMs. It provides a useful reference for future research on direct‐contact heat storage systems.