多孔介质复合相变材料孔隙结构优化与传热强化研究OA

This study systematically investigates the optimization mechanisms of graded porous skeleton structures on the heat transfer and thermal energy storage performance of composite phase change materials(C-PCMs).The effects of pore size distribution,pore size gradient,and porosity distribution on the phase change process are examined.A pore-scale physical model of porous media is constructed,and the enthalpy-porosity method is employed for numerical simulations to analyze the melting behavior,liquid-phase flow,and thermal storage characteristics of phase change materials(PCMs)with different pore structures.The results show that pore size distribution markedly influences the melting process under uniform porosity conditions.Arranging large pores near the heat source and small pores at the far end maximizes the synergistic effects of natural convection and conduction within large and small pores,reducing the melting time by 16.8%.Moreover,transverse gradient pore structures induce localized microconvection,particularly at the interfaces between large and small pores,where the liquid front exhibits pronounced curvature,enhancing average thermal storage efficiency by up to 17.5%during the later melting stage.In contrast,the impact of porosity distribution is relatively minor:although increasing the proportion of low-porosity regions near the heat source slightly shortens melting time,it decreases total heat storage and average storage power by up to 1.6%and 1.7%,respectively.Overall,this work elucidates the influence of pore structure on the melting heat transfer of C-PCMs and provides theoretical guidance for achieving efficient energy storage through rational design of pore size distribution,gradient structures,and porosity,offering valuable insights for optimizing inorganic porous C-PCMs.