Impact of structural parameters on thermal performance of phase change thermal storage device based on flat plate micro heat pipe

Phase change energy storage technology utilizes the state transition of phase change materials (PCMs) to store and release energy, offering advantages such as high energy storage density and operational efficiency. Nevertheless, practical applications still exist challenges including uneven temperature distribution and suboptimal thermal efficiency. To enhance the thermal performance of thermal storage devices (TSD), this study develops a configuration employing flat plate micro heat pipes (FPMHPs) and rectangular fins as primary heat transfer components. The thermal performance is significantly influenced by several key design parameters, including the heat pipe distribution, the structural configuration of the shell surface, as well as the geometric characteristics of the fins—specifically their arrangement, width, thickness, and spacing. The results reveal the following key findings: (1) The system achieved optimal thermal performance at a heat pipe distribution parameter of N = 1.5. (2) A shell configuration with L = 15 reduced the PCM melting time by 8.69 % compared to that of conventional shell designs. (3) While increasing fin thickness showed marginal improvements, expanding the fin width from 40 mm to 60 mm significantly decreases the melting duration by 41.67 % enhanced energy storage capacity by 43.2 %. (4) Reducing the fin spacing from 9 mm to 5.6 mm shortened melting time by 34.76 % and increased the stored energy by 1.54 %. These findings will provide essential data-driven insights and a robust theoretical foundation for the optimization of TSD performance.