加气混凝土典型自保温墙体结露问题数值判断

加气混凝土自保温结构是建筑外墙自保温的重要结构形式之一,分析该种墙体热桥的内表面是否会发生结露现象是节能设计中不可缺少的计算环节.本文采用CFD软件Fluent,用有限体积法对南京地区冬季粉煤灰加气混凝土典型自保温墙体结构的传热过程进行了数值模拟计算,得到了典型结构内部的温度场,并得到如下结论:冬季时,加气混凝土自保温墙体内表面温度最低点均处于热桥部位室内表面宽度的中心处或阴角处,应重点考虑这些部位的结露问题；冬季时,各种加气混凝土自保温墙体内表面的最低温度均在13.5℃以上,高于室内空气的露点温度,不会出现结露现象.

Numerical Analysis on the Condensation Problem of Typical Self-thermal Insulation Wall with Aerated Concrete

Aerated concrete self-thermal insulation construction is one of the important self-thermal insulation construction styles of exterior wall.Whether the condensation phenomenon will happen on interior surface of thermal bridges of this kind of wall is an essential calculation section during the energy conservation design.In this paper,the CFD software Fluent and finite volume method were used to simulate the heat transfer process of the typical fly ash aerated concrete self-thermal insulation wall in winter in Nanjing,and the inner temperature field was obtained.The simulation results indicated that the minimum temperature points of interior surface located at the center vertical lines on the width of interior surface of thermal bridges and the inside corners,the condensation problem of these positions should be seriously considered.Furthermore,the minimum temperature values of interior surfaces of different aerated concrete self-thermal insulation constructions were larger than 13.5 ℃,which was higher than the dew-point temperature of indoor air,the condensation phenomenon would not happen.