The simulation of heat transfer in phase change material melting based on the smoothed particle hydrodynamics method

Purpose In this paper, the Smooth Particle Hydrodynamics (SPH) method is used to numerically investigate heat transfer during phase change material (PCM) melting in a triplex-tube energy storage unit. The study analyzes the combined effects of fin positioning and nanomaterial incorporation on PCM melting. The purpose of this study is to investigate the mechanisms underlying enhanced heat transfer in three-tube phase change thermal storage systems. Design/methodology/approach To address computational instabilities in phase transition simulations using the SPHs method and to effectively characterize phase transition phenomena, a velocity correction algorithm for the mushy zone is introduced. The Boussinesq assumption is adopted to simulate natural convection under gravitational effects. To prevent unphysical particle penetration, a boundary repulsion method is used for wall surfaces. Findings Research shows that within the scope of this paper, a single-walled carbon nanotube (SWCNT) volume fraction of 5% maximizes thermal conductivity enhancement while minimizing convective suppression. Fin placement significantly influences the melting process. An offset arrangement of inner and outer fins optimizes heat flow pathways and enhances natural convection. The melting process accelerates with increased Stefan number, but average thermal storage power gains from further increases become progressively diminishing. Originality/value A multiphase SPH model for the melting of PCMs in triple-tube heat exchange units was developed and validated. The effects of factors such as the SWCNT volume fraction, fin position, fin length and Stefan number on the melting of PCMs were systematically investigated.