Effect of geometry modification on the thermal response of composite metal foam/phase change material for thermal energy storage

In this study, seven vertical shell-tube latent heat storage (LHS) systems are built to explore the effect of geometry on the melting and solidification behavior of phase change material (PCM). The performances of these systems using pure PCM (paraffin RT82) and composite PCM (paraffin RT82 embedded in copper foam) are investigated. Two-dimensional numerical model based on the enthalpy-porosity method and two-temperature energy equations is developed and verified with the experimental data. The solid-liquid interface, isotherms, time histories of liquid fraction and stored energy are used to evaluate the thermal performance. Results show that the conical shell system enhances natural convection compared with the cylinder system, whereas the frustum tube system enhances both convection and conduction. Geometry modification has little effect on the thermal performance of composite metal foam/PCM. Compared with the cylinder LHS system, the complete melting time with geometry modification is reduced by at least 9.2% for pure PCM, and less than 5.9% for composite metal foam/PCM. Moreover, it is also found that the frustum tube system outperforms the conical shell system in both melting and solidification, regardless of metal foam and HTF material. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

The study investigated the effect of geometry on the melting and solidification behavior of phase change material in vertical shell-tube latent heat storage systems. Different geometries were found to enhance natural convection and conduction, affecting the thermal performance. Geometry modification had little impact on the thermal performance of composite metal foam/PCM, but significantly reduced the melting time of pure PCM.