Innovative approaches to thermal energy storage: The role of porous media and rotational techniques

Active and passive methods in energy storage play a crucial role in significantly improving the performance of storage systems. This study numerically investigates an energy storage reservoir featuring a heated pipe at its center, designed with a cylindrical geometry. The effects of rotation, as an active method, and a porous medium, as a passive method, are analyzed simultaneously on energy storage performance. Different rotation patterns, both continuous and instantaneous, at varying speeds, as well as two distinct volumes of the porous medium with different geometries, are evaluated. The results demonstrate that the application of this hybrid approach can substantially reduce charging times. The impact of rotation on energy storage performance varies depending on the geometries of the porous medium. In the semi-porous case, the effect of rotation influences the liquid fraction changes at lower times compared to the fully porous case. In the fully porous state, the charging time can be reduced by up to 30.59 %. For the semi-porous case, the 4-Part Porous Rotating Storage Unit shows an improvement in energy storage time of up to 57.7 %. These findings highlight the potential of combining active and passive methods to optimize energy storage systems in practical applications. • The combined effects of rotation and porous media on energy storage performance were investigated. • A total of 10 configurations, incorporating various porous geometries and rotation speeds, were analyzed. • Rotation combined with a porous medium can reduce melting time by more than 50 % in certain configurations. • Charging time is reduced by up to 30.59 % in fully porous cases and by 57.7 % in semi-porous cases.