Nonlinear Effect of Moisture Content on Thermal Conductivity of Building Materials with Different Pore Size Distribution.
Affiliation of Author(s):
建筑设备科学与工程学院
Journal:
International Journal of Thermo physics
Key Words:
中文关键字：建筑材料; 有效导热系数; 湿组分; 湿传递; 非线性; 孔径分布，英文关键字：Building materials; Effective thermal conductivity
Abstract:
Understanding the quantitative relationship between the effective thermal conductivity and the moisture content of a material is required to accurately calculate the envelope heat and mass transfer and, subsequently, the building energy consumption. We experimentally analyzed the pore size distributions and porosities of common building materials and the influence of the moisture content on the effective thermal conductivity of building materials. We determined the quantitative relationship between the effective thermal conductivity and moisture content of building materials. The results showed that a larger porosity led to a more significant effect of the moisture content on the effective thermal conductivity. When the volumetric moisture content reached 10 %, the thermal conductivities of foam concrete and aerated concrete increased by approximately 200 % and 100 %, respectively. The effective thermal conductivity increased rapidly in the low moisture content range and increased slowly in the high moisture content range. The effective thermal conductivity is related to the moisture content of the materials through an approximate power function. As the moisture content in the walls of a new building stabilizes, the effective thermal conductivity of normal concrete varies only slightly, whereas that of aerated concrete varies more significantly. The effective thermal conductivity of the material is proportional to the relative humidity of the environment. This trend is most noticeable when the wall material is aerated concrete.
First Author:
liujiaping,wangyingying,wangdengjia,liuyanfeng
Paper Publications
