Energetic Analysis of Packed Bed Latent Heat Storage Systems

Nowadays, with the rapid growths in world population and economy, the world energy demand and consumption have increased enormously which led to a wide variety of harsh environmental impacts [1]. As a potential solution for energy conservation storing the excess energy to fill the gap between energy supply and demand, using phase change materials (PCMs) has received much attention. Thermal energy storage with PCM is a promising technology based on the principle of latent heat thermal energy storage (LHTES)[2], where PCM absorbs or releases large amounts of energy at a certain temperature during the phase change transition period (charging and discharging process), with a high heat of fusion around its phase change temperature range [3]. Thermal energy storage in packed beds is receiving increased attention as a necessary component for efficient implementation of concentrated solar power plants. In this study, the thermal characteristics, during a single charge period, of a packed bed made of PCM filled spherical capsules is presented. It was found that the energy efficiency of the system proved to be very sensitive to the choice of the PCM melting temperature.