Cooperative optimization of heat conduction and natural convection in composite phase-change materials

The introduction of metal skeletons significantly improves the heat conduction efficiency of phase-change materials, but weakens natural flow characteristics and increases overall mass. In this paper, the thermal properties of composite phase-change materials were analyzed by numerical simulation, and the effects of porosity on heat conduction, natural convection and light mass were investigated. The key design variables were selected and the response surface regression equation was constructed using the Box-Behnken experimental method. The heat conduction contribution, natural convection contribution and weight were optimized by NSGA-Ⅱ multi-objective genetic algorithm, and the optimal solution set was selected by TOPSIS selection method. The results showed that the basic scheme could balance heat conduction (84.44%), natural flow (15.56%) and lightweight (2.23g) according to different weights. The heat conduction efficiency of w₁ scheme which focused on heat conduction was as high as 86.41%. The flow contribution of the w₂ scheme which focused on natural flow could reach 18.51%. The quality of w₃ scheme which focused on light weight was reduced to 2.15g. Based on the above analysis, the overall performance regulation laws of composite phase-change materials under different requirements were obtained, which provided theoretical guidance for micro scale thermal management technology and composite phase-change materials design.