Effect of Graphite Particle Size on the Thermal Properties of EG/Erythritol CPCM

Erythritol (ET) is a promising medium–low temperature organic phase change material. To solve the problems of supercooling, leakage, and low thermal conductivity, expanded graphite (EG) with four different particle sizes of 32 mesh, 50 mesh, 80 mesh, and 100 mesh was used as supporting material. A shape-stabilized composite phase change material (CPCM) with a mass ratio of EG to ET of 9:1 was prepared by the ultrasonic impregnation method. The properties were tested and analyzed by DSC, SEM, FTIR, XRD, and TGA. The experimental results showed that 50 mesh EG was more suitable as an adsorption carrier for erythritol among the four different particle sizes of EG. Compared with pure erythritol, the supercooling degree of 50 mesh EG/ET composite decreased by 35.2 %, the latent heat of solidification increased by 8 %, and the thermal conductivity increased by 250.8 %, which increased the heat storage and release capacity of the material by 19.2 %, and the 50 mesh EG/ET composite phase change material had good thermal stability. In this study, the relationship between the supercooling degree of EG/ET and EG particle size was analyzed, and EG/ET thermal storage materials with high thermal storage density and exothermic density were prepared. It helps to promote the application of EG-based composite thermal storage materials and the development of thermal storage technology.