Abstract: The technique of high temperature thermal storage is one of the critical techniques of a solar dynamic power system. Solid liquid phase change latent thermal storage is commonly used. The volume of most salts will contract while changing from liquid to solid, which leads to the forming of void in the container. The void enlarges heat resistance, and then affects the phase change heat transfer process. The differences of solid liquid phase change heat transfer process between two different void positions are analyzed through numerical simulation.

Key words: lat ent thermal energy, therma l storage, enthalpy, phase change mater ial, void