热湿气候地区保温复合墙体内部冷凝研究

摘要

According to the work of Motakef and EI-Masri, the wall is divided into dry-wet-dry zones. Based on the heat and moisture transfer through porous media, considered the vapor condensation as a vapor sink, water source and heat source, coupled heat and moisture equations for wet zone were established. Closed-form analytical expressions for the condensation rate, moisture content and the time at which critical moisture content value is reached are obtained. The analysis has indicated that the condensation rate exhibits a strong dependence on the ratio of temperature drops across the wet zone to the square of that zone width and the maximum condensation rate value is reached at the boundary of wet zone close to lower temperature.%根据Motakef和El-Masri的研究,将墙体分为“干—湿—干”三个区域.以多孔介质传热传质学为基础,将水蒸气冷凝看成是湿源、热源、蒸汽汇,建立起墙体热湿耦合传递方程.通过分析解得到了墙体内冷凝率和液态含湿量的分布曲线以及达到临界含湿量所需的时间.分析结果表明墙体内的冷凝率跟湿区域两侧的温差成正比,最大冷凝率出现在低温侧的湿区域边界处.根据湿分布情况得出了导热系数的变化情况.最后,以石膏板—玻璃纤维—砖墙复合墙体为例,分析了热湿气候地区墙体内部冷凝情况及其对导热系数的影响.