Theoretical study of heat transfer model of silica aerogel based on the porous structure of secondary particles

Abstract

In this paper, the secondary particles of silica aerogels are equivalently modeled using the spherical hollow cube model, and the heat transfer of porous silica aerogels are linked to their internal structural parameters, thus establishing a theoretical model of the heat transmission process of porous silica aerogels formed by the interconnected accumulation of secondary particles. The model analyzes and calculates the pertinent parameters as well as the overall thermal conductivity while accounting for the secondary particles' porous structure. It then compares its predictions with experimental results and predictions from other models for various pressures and temperatures. The results demonstrate good agreement between the constructed model and the experimental data, the deviation is controlled within 12% and the minimum deviation can reach 1.6%. The model is beneficial for enhancing the thermal insulation performance of nanoporous aerogels because it is effective in predicting the heat transmission process within the porous medium silica aerogel.