A phase field model for heat transfer in a metal foam-embedded latent thermal energy storage (LTES) system

Abstract

A phase field model substitutes the boundary conditions by partial differential equations for the evolutions of phase fields. Therefore this mathematical method deals with free boundary problems without having to trace phase interface positions. Phase field model is for the first time employed to solve the phase change problem in a metal foam-embedded Latent Thermal Energy storage (LTES) system. It provides great potentials of being extended to consider complicated mechanism during melting: coupled phase change and volume change of PCMs. Validation studies are also carried out by comprising results between the model predictions and the experimental data in existing literatures. Two dimensionless groups of the material and structure parameters are identified to control the effectiveness of the system. An Effectiveness Map is also produced to distinguish the conditions under which incorporating metal foam into the PCMs is sensitive, lowly sensitive or irrelevant. The map provides a useful tool to guide the metal selection and structure design of the metal foams when used to enhance heat transfer property of PCMs. Finally case studies are also carried out by applying the map.