玻化微珠保温砂浆导热系数模型研究

基于最小热阻力法则和均匀化方法估算了玻化微珠保温砂浆的等效导热系数.用ANSYS模拟玻化微珠保温砂浆二维单元胞体的热传导,发现对热阻网络的横向热阻的极端考虑会给计算结果带来误差.用ANSYS计算的三维单元体模型的等效导热系数值与3种理论计算值进行比较,发现用假设横向热阻无穷小与假设横向热阻无穷大求得的单元体等效热阻的平均值作为单元体的等效热阻来求单元体等效导热系数更精确,最后实验也验证了这一结论.实验值与本文提出的理论模型计算值偏差仅为0.2%,证明用该方法来估算玻化微珠保温砂浆的导热系数是可行的.

Study on the Thermal Conductivity Model of Hollow Beads Insulating Mortar

Based on the minimum thermal resistance theory and homogenization method, the effective thermal conductivity of hollow beads insulating mortar was estimated. With ANSYS imitating the heat transmission of the 2D unit model of hollow beads insulating mortar, we can find it will bring about calculation errors by considering the extreme cases of the transverse thermal resistance of resistance network. Compared with the effective thermal conductivity of 3D unit cell model calculated by ANSYS with three kinds of theoretical calculating value, it is more accurate than the effective thermal conductivity of unit calculated by the model of effective thermal resistance average. A model was built by assuming transverse thermal resistance infinitesimal and infinite. Final laboratory finding also confirms this conclusion. With only 0.2% deviation between the experiment values and the calculation of theoretical model, it is feasible to estimate the effective thermal conductivity of hollow bead insulating mortar.