Computational Studies on Metal Foam and Heat Pipe Enhanced Latent Thermal Energy Storage

Abstract

Thermal energy storage is a distinguishing component of a concentrating solar power (CSP) system, which enables uninterrupted operation of plant during periods of cloudy or intermittent solar availability. Latent thermal energy storage (LTES) which utilizes phase change material (PCM) as a heat storage medium is attractive due to its high energy storage density and low capital cost. However, the low thermal conductivity of the PCM restricts its solidification rate, leading to inefficient heat transfer between the PCM and the heat transfer fluid which carries thermal energy to the power block. To address this limitation, LTES embedded with heat pipes and PCM's stored within the framework of porous metal foam that have one to two orders of magnitude higher thermal conductivity than the PCM are considered in the present study. A transient, computational analysis of the metal foam enhanced LTES system with embedded heat pipes is performed to investigate the enhancement in the thermal performance of the system for different arrangements of heat pipes and design parameters of metal foam, during both charging and discharging operation.