Physical simulation and enhancement design of the below-tye material heat exchanger

Abstract

Phase change material (PCM) based thermal energy storage (TES) is attractive for waste heat recovery and thermal management due to its high energy density and near-isothermal heat storage/release characteristics. To address the performance differences and optimization needs associated with TES configurations, operating conditions, and PCM selection, this work conducts a thermo-physical numerical study and performance comparison of two representative TES units: a shell-and-tube TES and a packed-bed TES. Multi-physics coupled models were developed in COMSOL Multiphysics under unified boundary conditions and a consistent stopping criterion (simulation terminated when the minimum PCM-domain temperature reached 70∘C). A unified evaluation framework was established using the volume-averaged liquid fraction β, the volumetric energy density of PCM Ev,pcm and the volumetric power Pv, enabling fair comparisons across configurations and materials.