Comparative study of two types of medium temperature phase change materials

Abstract

This work presents a numerical comparative study of the melting and solidification processes of two medium temperature phase change materials (PCMs) for latent heat thermal energy storage (LHTES) applications. The PCMs compared are an inorganic solar salt and a Sn-based metal alloy, with the phase change temperatures around 220°C. The numerical comparative study was conducted in a 2D rectangular unit model with constant heat flux, the simulations were conducted deploying the enthalpy method in Ansys FLUENT software. The numerical results were validated using experimental results for one of the phase change materials studied. The charging and discharging times of the designed LHTES were studied for both phase change materials, finding that the metallic PCM LHTES showing superior performance. The charging and discharging time obtained for the solar salt LHTES, duplicate the time required using metallic PCM LHTES. Moreover, the final average temperature for the solar salt LHTES, shows significantly compare with the phase change temperature.