Influence of Inclined Non-Uniform Fins on the Melting of Phase Change Materials Under Constant-Power Heating Condition

The low thermal conductivity of phase change materials (PCMs) limits their widespread application in practical energy storage systems. The integration of fins has emerged as an effective approach to enhance PCM melting rates. This study numerically investigates the effects of fin length and tilt angle variations on PCM melting processes through two-dimensional modeling. A rectangular container with vertical constant-power heating was simulated, which incorporated natural convection effects. Initially, the analysis of equal-length fins with varying dimensions revealed that longer fins and appropriate tilt angles could significantly accelerate the PCM melting. Subsequent investigation under constant total fin lengths demonstrated that two factors enhanced the heat transfer and reduced the melting duration: large fin length differences and the enclosed regions between the fins and the container bottom. Studies of extreme tilt angles during angular variation indicated that the configuration with a 30 mm length difference with limit angles could positively affect the melting performance. The findings offer valuable insights for the optimal design of phase change energy storage systems.