In this paper

homogeneous metal skeleton and gradient porosity skeleton are constructed by three-periodic minimal surface method ( TPMS). Based on the pore scale

the finite element method is used to simulate the solidification process with the solidification process of pure paraffin cavity

and investigate the influence law of the skeleton structure in the solidification of composite phase change material. Through the comprehensive analysis of solid-liquid phase change interface

overall solid phase rate

Nu number of cold source wall and cold storage performance

the following conclusion was obtained: Adding TPMS skeleton to the phase change cavity and the porosity of 0.78 phase change cavity was 94.1% shorter than the solidification time of pure paraffin phase change cavity

and the cooling storage rate was increased by 12.98 times. At the average porosity of 0.84

the porosity increases the solidification time of the cavity along the positive direction of x is the shortest

reducing the solidification time by 93.5%

and increasing the cooling storage rate by 12.60 times; the solidification time by 12.23% and the cooling storage rate by 15.3%.