Heat Transfer Behaviors of Parallel Plate Systems in Sensible Thermal Energy Storage

In the present investigation a simplified analysis is accomplished to handle a parallel plate system with parallel channels as a porous media and to evaluate the permeability, inertia coefficient, the interfacial heat transfer coefficient between solid matrix and fluid and the specific area for the equivalent porous medium. In the local heat transfer coefficient is also considered the radiative heat transfer which will be temperature dependent. The evaluation of these two terms will be carried out numerically by the Ansys-Fluent code to compare the simplified and numerical model results. The analysis should allow the estimation of an optimized configuration, in terms of number of pore per inch (PPI) or channels per unit of length (CPL), as a balance between pressure drop and heat transfer rate inside the parallel plates configuration. Results show the effects of storage medium, different porosity values, porosity effect and mass flow rate on stored thermal energy and storage time. Results in terms of stored thermal energy as function of time are presented. Moreover, the behavior related to fluid pressure losses and internal heat transfer is analyzed. (C) 2017 The Authors. Published by Elsevier Ltd.