Numerical investigation on sensible thermal energy storage with porous media for high temperature solar systems

In this paper different high temperature TES components are numerically analyzed. The difference is defined by the different type of porous medium employed in the storage. Two different porous media are considered: spheres or foams. In all cases a ceramic material is considered. In the formulation of the model it is assumed that the system geometry is cylindrical, the fluid and the solid thermophysical properties are temperature independents, the radiation heat transfer mechanism is taken into account. The commercial CFD Fluent code is used to solve the governing equations in transient regime and in local thermal non-equilibrium (LTNE). Numerical simulations are carried out at different mass flow rates of the heat-carrying fluid. The results show the effects of the porosity and of the working fluid mass flow rate on the stored thermal energy and on the storage time.