Thermal transport augmentation in latent heat thermal energy storage system by partially filled metal foam: A novel configuration

Abstract

Abstract Thermal transport augmentation in latent heat thermal energy storage (LHTES) system by local installation of metal foam-phase change material (PCM) composite is presented in the current work. The study highlights an optimal concentration and position of metal foam-PCM composite (MFPC) to elevate thermal performance without altering an overall melting time. Thus, a novel configuration MFPC is proposed according to the optimum thermal conductivity enhancer (TCE) density, a criterion defined based on the temporal variation of local temperature gradient during the melting process. The fundamental principle of the criterion is positioning the metal foam only at the maximum thermal potential region for the effective utilization efficiency of the metal foam. A numerical code based on a local thermal non-equilibrium coupled enthalpy porosity approach is developed and validated. The numerical results showed that the proposed configuration with the provision of MFPC at a high thermal potential region alleviates local conductive transport with enhancement in the overall melting rate. It is seen that the withdrawal of metal mass at low thermal potential region encompasses the beneficial influence of natural convective transport, which is observed to be impeded in the previous configuration. The total melting time is observed to be equal for the proposed configuration when compared to the LHTES with the full volume of metal foam. The elimination of metal mass can increase the mass of PCM and thermal energy storage capacity. Additionally, it can assist to reduce weight and economy of the LHTES system.