Performance Evaluation of Packed Bed Energy Storage System: A Simulation Study

Abstract

Packed bed energy storage (PBES) is an alternative system for thermal energy storage through a
sensible heat storage mechanism. With relatively local construction, PBES is suitable for various
purposes for both low and high temperature applications. It is packed with materials that do not
undergo phase change over the temperature range during the storage process. The materials have
good thermal storage capacity and effective thermal conductivity. The outer tank, insulation, inlet
and outlet pipelines, heat transfer fluid and energy source make up the system. This study aims to
simulate the system, and analyse its thermal energy behaviour including, absorption and heat
retention. For this study, the materials for the tank, insulation, and heat transfer fluid have been
selected using the Pugh Matrix Method. Steatite, Basalt rock and Sand are chosen as packing
materials due to their relatively desirable cost, availability and thermal properties. The simulation is
conducted in TRNSYS with the components: pump, boiler, tank and segmented rock beds. Heat
retention and the temperature change of the packed bed system are studied across different layers
and arrangements. It is observed through the simulation that the layer of basalt, followed by steatite,
and then sand showed better heat retention for identical ambient conditions and processes.