Phase transition enhancement through circumferentially arranging multiple phase change materials in a concentric tube

Abstract

In this paper, circumferentially arranging multiple phase change materials (PCMs) in a finned concentric tube thermal energy storage (TES) system is proposed to improve the phase transition uniformity. The phase transition area is divided into three regions by fins and filled with different PCMs. The effects of multiple PCMs arrangements and fins distributions on the thermal performance of the TES system were numerically studied using commercial software ANSYS FLUENT. The phase transition and energy storage rates were examined. Results demonstrate that using multiple PCMs shortens the melting-solidification time compared with using single PCM. The enhancement potential increases with the decrease of temperature difference between HTF and PCM. Multiple PCMs with non-uniform fins angle further enhances melting and solidification. The optimal case with multiple PCMs saves 14.7% melting-solidification time compared to the case with single PCM.