Numerical modeling and multi-parameter study of porous media packed-bed latent heat thermal energy storage systems

Abstract

This investigation looked at using packed-bed thermal energy storage (TES) systems with phase-change materials (PCM) to improve the efficiency of latent heat storage in solar thermal systems. The effects of the diameter of the particles in the bed, the porosity of the bed, the inlet temperature and the heat flux on the time to charge the system, the propagation of the thermal front, and the change in the liquid fraction were analyzed using numerical simulations under local thermal non-equilibrium (LTNE) conditions. The results indicated that the melting was not uniform along the bed, that the fluid was responsive to heat earlier than the solid matrix, and that the process of phase change occurred differently at different locations in the bed. The results will assist in developing an optimized design for TES, improving the charge performance of TES, and increasing the energy density and power output from the packed-bed PCM system.