中文摘要：

根据硬硅钙石-气凝胶复合绝热材料的微观结构特点，建立了描述材料内气固耦合导热的三维单元体传热模型．通过模型计算对硬硅钙石型硅酸钙、气凝胶及硬硅钙石-气凝胶复合绝热材料的导热系数进行了对比研究．结果表明：硬硅钙石型硅酸钙密度是影响复合绝热材料有效导热系数的关键因素，而气凝胶密度的影响不大；在高温下，复合绝热材料的导热系数要明显低于硬硅钙石型硅酸钙及二氧化硅气凝胶的导热系数．

英文摘要：

Based on the microstructure features of xonotlite-aerogel composite insulation material, a three dimensional unit cell model was developed for the coupled heat transfer of gas and solid in the material. The effective thermal conductivities of xonotlite-type calcium silicate, aerogel and xonotlite-aerogel composite insulation material were compared by model calculation. The results show that the density of xonotlite-type calcium silicate has great influence on the effective thermal conductivity of xonotlite-aerogel composite insulation material, but the density of aerogel has little influence. The effective thermal conductivity of xonotlite-aerogel composite insulation material is apparently lower than those of xonotlite-type calcium silicate and aerogel at an elevated temperature.