Development of PCM-based shell-and-tube thermal energy storages for efficient EV thermal management

Electric vehicles face significant challenges in cold climates. Battery efficiency decreases, and cabin heating demands additional electricity, which diminishes the energy available for vehicle propulsion. In this context, a thermal energy storage system based on a phase change material (PCM) with diverse designs of shell -and -tube heat exchangers is investigated to meet cabin thermal load demands independently. A simulation model for a two-phase PCM heat exchanger is developed and validated using experimental data. The comparison revealed average temperature differences of 1.59 K and 1.61 K for the melting and solidification processes, respectively. Compared to the single tube design, the heat transfer performance of finned multitube design improved the melting process and reduced the melting time by 92.9% and reduced the solidification time by 87.6%. The average heat transfer rate of the finned multitube during the solidification process is 2.9 times higher than that of the single tube. Additionally, the use of PCM incorporating different types of nanomaterials is explored to enhance the melting and solidification performance through increased thermal conductivity. The graphene nanoplatelet PCM exhibited the most substantial improvements in thermal conductivity, resulting in melting and solidification time reductions by 54.2% and 48.9%, respectively.