Development of heat transfer enhancement of a novel composite phase change material with adjustable phase change temperature

Latent thermal energy storage plays an indispensable role in exhaust heat recycles in various industries which is useful for reducing energy consumption. Different phase change temperatures and high thermal conductivities of composite phase change materials were required for various domains. In the present work, Alum as phase change material and Ala as melting point modifier, a series of phase change materials with adjustable melting temperatures were prepared by physical mixing method. Moreover, EG as porous skeleton and thermal conductive enhancer, composite with high thermal conductivity was obtained with simple physical adsorption method. The XRD and SEM were applied to characterize the phase crystal and microstructure of the composite phase change material. DSC results revealed that phase change temperatures of Alum-Ala mixtures could be adjustable from 91.11 °C to 74.61 °C and thermal conductivity of the composite was improved to 10.93 W·m−1·K−1, which is 21.9 times of pristine Alum-Ala mixture. The infrared thermography and temperature-time curves were obtained to represent the heat transfer performance and the subcooling degree intuitively. The subcooling degree was decreased from 2.238 K to 1.866 K. The result of TGA indicated that the composite possessed favorable thermal stability during the operating temperature. From the result, the composite obtained in the present work is a prospective candidate for exhaust heat recycles. •The Alum-Ala/EG composite was prepared with Sod as nucleating agent.•The melting temperature of the composite was adjustable from 74.61 to 91.11 °C.•Thermal conductivity was improved to 10.93 W·m−1·K−1 with an intensifying factor of 21.9.•The composite possessed favorable thermal stability and temperature regulated properties.