Optimization of Pin Fins for a Heat Exchanger by Entropy Generation Minimization and Constructal Law

Abstract

Pinfins are considered as one of the best elements for heat transfer enhancement in heat exchangers. In this study, the topology of pinfins (length, diameter, and shape) is optimized based on the entropy generation minimization (EGM) theory coupled with the constructal law (CL). Such pinfins are employed in a heat exchanger in a sensible thermal energy storage (TES) system so as to enhance the rate of heat transfer. First, the EGM method is used to obtain the optimal length of pinfins, and then the CL is applied to get the optimal diameter and shape of pinfins. Reliable computational fluid dynamics (CFD) simulations of various constructal pinfin models are performed, and detailed flow and heat transfer characteristics are presented. The results show that by using the proposed system with optimized pinfin heat exchanger the stored thermal energy can be increased by 10.2%.