Energy and Exergetic Analysis of Thermal Transport in Latent Heat Thermal Energy Storage Systems Impregnated with Metal Foam

Abstract

A thermal performance of the metal foam impregnated phase change material (PCM) is widely evaluated based on the first law of thermodynamics. It is, however, rare to avail literature that report energetic, as well as exergetic analysis of metal foam-PCM composite (MFPC) infused latent heat thermal energy storage (LHTES) systems. The thermal performance of such system is, therefore, investigated using the first and second law of thermodynamics during the melting process in a present study. The influence of metal foam porosity on thermal transport is analysed. A numerical code is developed to realize the enhancement in thermal performance. Results show that phase change thermal transport can be improved substantially by infusion of a metal foam. The conduction as mode of heat transport dominates the melting process, while the natural convective transport is observed to be hindered with a decrease in the metal foam porosity. The metal foam with porosity of 0.97 and 0.90 improves the overall melting rate by 40% and 66.67%, respectively, compared to the pure PCM. It is observed that the reduction in the porosity eliminates the high temperature difference and, hence, an entropy generation rate/irreversibility. Subsequently, the steady state exergetic efficiency is found to be 89.20% and 97.87% using pure PCM and MFPC, respectively.