大多数建筑墙体均为多孔介质材料,多孔介质墙体中湿迁移与热迁移是互相耦合的过程,湿迁移对热迁移有着重要的作用,例如会使热导率明显增加,同时,热过程对湿过程也有着影响作用。基于Fourier定律、Fick定律、Darcy定律,以温度和空气含湿量为驱动势建立了多层多孔介质墙体热湿耦合迁移数学模型,对两种常见墙体(红砖墙体和加气混凝土墙体)进行计算分析。结果表明,加气混凝土墙体比红砖墙体具有更好的保温隔热性能,但更容易发生湿积累和引发湿破坏。
Most building walls are composed by porous materials, in which heat transfer is coupled with moisture transfer, and moisture transfer has a great effect on heat transfer, e.g., leading an obvious in- crease to the thermal conductivity, and conversely heat transfer has a great effect on moisture transfer. Based on Fourier law, Fick law and Darcy law, with the critical potentials of temperature and air moisture content, a coupled heat and moisture transfer model was proposed, and used to analyze the heat and mois- ture transfer characteristic in two common walls(the red brick wall and aerated concrete wall). Results show that compared with red brick wall, aerated concrete wall has better insulation property, but easily accumu- lates moisture and suffers from moisture damaze.