Numerical and optimization study on heat storage and release process of novel fin-metal foam composite structures under periodic heat source

This research uses numerical analysis to explore the comprehensive process of heat storage and release in a square phase change heat storage unit. A combination of fins and metal foam enhances heat transfer, along with a periodic sinusoidal heat source for heating and releasing storage. An experimental setup is constructed to validate the numerical analysis. The Box-Behnken design in the response surface method is applied for experimental optimization, indicating that fin position and metal foam pore density do not affect the volume of phase change material. Findings show that the initial structure with evenly distributed fins displays a refractory zone at the final phase transformation, and the temperature variation fluctuates due to heat source instability. Optimal outcomes suggest that increasing transverse fin spacing leads to a continuous reduction in total storage-release time. Moreover, increasing longitudinal fin spacing and pore density initially decreases and then increases the total storage-release time. The optimal structure achieved results in a substantial 29.55% decrease in total storage-release time, a 20.74% increase in average heat storage rate, and a 65.75% increase in average heat release rate during solidification compared to Case 1. Though the optimal case’s heat charging and discharging show a slight decline, the primary control of heat storage-release through latent heat shows minimal overall influence.