Abstract: It introduces the concepts and working principles of thermal diode，as well as therm ophysical properties which solar phase—change materials should have．Some experiments are also performed to study heat transfer performance of thermal diode and phase—change rules of energy storage materials．Experimental results show that ther．real diode has a good start—up performance and isotherm al heat transfer characteristics． When the working fluid filling rate in the heating section is about 85％ ．heat transfer eficiency of thermal diode and coeficient of heat transfer in the condenser section can be achieved to the best value．Meanwhile，there exists non-uniform Dhase transiti0n in the inner part of material，and the heat transfer coefi cient between the condenser section and the material is small．

Key words: thermal diode；energy storage material；heat transfer coeficient