Experimental and Computational Fluid Dynamics Analysis of Energy Storage in Packed Bed Direct Contact Heat Exchanger

Abstract

This work presents a Computational and experimental study of transient heat transfer in fluid flow through porous media. The process of heat transfer and fluid flow through porous media is of interest to a wide range of applications of such as reactors, separators and dryers etc. Porous media used here is packed bed of spheres. The experimental arrangement comprises spheres of high carbon steel which are randomly packed in a 450 mm hollow tube of 45 mm inner diameter. The diameters of carbon steel spheres are 10 mm. The arrangement resulted in a porosity is 0.47. Hot air from a source was allowed to flow into the packed bed at various inlet conditions of velocity varying from 2.5 to 4 m/s and temperature ranging from 104°C to 39° C. The spheres were heated from initial temperatures of 30°C to near steady state conditions. ‘K’ type thermocouples were used to sense the temperatures. Three dimensional geometrical model of the storage system were modeled, meshed and simulated by using some commercial CFD software package. The thermal performance of storage system and also energy storage capacity were increased. The result of computational analysis was compared to the experimental analysis of validations.