Second-law design of a latent heat thermal energy storage with branched fins

Abstract

Purpose – The purpose of this paper is to investigate efficient designs of a shell-and-tube latent thermal energy storage system through an approach based on the analysis of entropy generation. It proposes innovative branched fins to maximize the performance of the system. Design/methodology/approach – A computational fluid dynamic (CFD) model is first used to detail the thermo-fluid dynamic transient behavior of the latent heat storage system. The model account for phase change, buoyancy driven fluid flow and heat transfer during the process of energy retrieval from the storage unit (solidification). The CFD model is then used to evaluate locally the entropy generation rate during the process. On the basis of the insight gathered through the analysis of the entropy generation, the design of the fins is gradually modified aiming at the maximization of the performance of the storage system. Findings – The best fins design leads to a twofold increase of the solidification rate in the latent heat storage uni...