Keywords: liquid?solid phase change, natural convection, porous medium, supercooling phenomenon, numerical simulation, fluid flow, heat transfer, thermal energy storage, solidification
Numerical simulation of fluid flow and heat transfer in a phase change thermal energy storage
The objective of this work is the study of an industrial process of energy storage which consists in the use of a cylindrical tank filled with encapsulated Phase Change Materials (PCM). A particularity is present in this kind of processes; it concerns the delay of the crystallisation of PCM, called supercooling phenomenon. The development of a 2D porous-medium model for cold storage with coolant flowing enables a detailed analysis of this process. Fluid flows, forced and natural convections as well as the supercooling phenomenon in these packed capsules were particularly analysed using a thermal non-equilibrium model. The solidification process inside the spherical capsules is treated by employing the quasi-stationary formulation. The effects of different parameters on the behaviour of the tank, such as capsule size, porosity of the packed capsules and the tank dimension are examined when the tank is in horizontal position.