Study on Heat Transfer of Copper Foam Microstructure in Phase Change Materials

The foam metal, possessing a remarkable skeletal framework, exhibits outstanding specific strength and stiffness, in conjunction with excellent thermal conductivity. Its spatially continuous porous structure not only promotes the infiltration of phase change materials but also renders it an extraordinary enhancer of thermal conductivity within phase change energy storage systems. In order to comprehensively explore the influence of copper foam structure on the heat transfer characteristics of phase change materials, this study constructs a series of structural models of copper foam frames with diverse configurations. By leveraging the finite element analysis approach, it meticulously simulates the melting processes of five unique composite copper foam structures, namely Kelvin, Gyroid, IWP, Primitive, and Hollow hexahedral. Through a detailed analysis of thermal conductivity associated with each structural model, as well as the flux variation and average temperature under a constant flow, the study scrutinizes the heat transfer properties of these disparate structures. The obtained results will provide substantial theoretical support for the optimization design of heat transfer performance in phase change heat storage systems. The results indicate that the effective thermal conductivity of MFPCMs largely depends on the structural type and its unique configuration, rather than just the porosity of the structure. Under isothermal conditions, using the melting time of the Kelvin model as a baseline, the melting time of the PCM in the Gyroid structure was reduced by approximately 20.9%, the IWP structure by 3.8%, the Primitive structure by 28.6%, and the hollow hexahedral structure by 29.9%. Under constant heat flux conditions, the melting time of the phase change material does not depend on the type of metal foam structure. The heat transfer performance of the other structures is all superior to that of the Kelvin structure. At around 150 s, all structures had their PCM completely melted, at which point the highest temperature was observed in the MFPCM based on the primitive structure, and there may be potential for further temperature increase if further studies are conducted. Therefore, these new structures hold broad application prospects in phase change energy storage systems.