A review of the composite phase change materials: Fabrication, characterization, mathematical modeling and application to performance enhancement
Phase change materials (PCMs) are frequently and widely used in latent thermal energy storage (LTES) system and thermal management (TM) system due to their large latent heats and capabilities of maintaining nearly constant temperature. However, the performances of PCMs in LTES and TM systems are seriously limited by their low thermal conductivities and poor heat transfer performances, which consequently stimulates intensive experimental and theoretical investigations on improving the thermal conductivities and heat transfer performances of PCMs by using different methods. The present paper reviews the recent progresses of the investigations and applications of the composite PCMs with the enhanced performance. The focuses are placed on the composite PCMs fabricated by using the metal foams and carbon materials, which have been proved to be the most promising approaches for thermal conductivity and heat transfer promotion on PCMs. The fabrication processes of the composite PCMs are first introduced in the present paper followed by the thermal characterization. The measurement of the effective thermal conductivities of the composite PCMs is discussed in detail by comparing different measuring methods, and the theoretical models to predict the effective thermal conductivities of the composite PCMs are also presented. The mathematical models describing the phase change heat transfer characteristics of the composite PCMs which are very important for system modeling and design are also addressed and discussed in the present review. Furthermore, the applications of the composite PCMs to LTES and TM systems are introduced and summarized by illustrating the typical examples. It can be understood that the composite PCMs can effectively improve the performances of LTES and TM systems, which therefore calls for the further investigation in this research field. Finally, the future research topics are suggested.