湿传递对建筑墙体传热性能的影响

建筑物的耗能与建筑围护结构的传热传湿密切相关,了解建筑墙体内部的热湿传递对建筑节能有重要影响。以相对湿度和温度梯度为驱动势建立墙体一维非稳态热、湿和空气耦合传递模型(HAM模型),并利用有限元法进行了数值求解,重点关注了湿传递对传热的影响。数值结果表明:考虑传湿时墙体内部温度波动小,墙体进行热湿传递会产生湿积累,降低墙体使用年限;考虑传湿时通过墙体总传热量比不考虑传湿时多7.5%;考虑传湿时内壁面最大平均数比不考虑传湿时大0.78。

Moisture Transfer Effects on Heat Transfer Performance of Building Wall

Building energy dissipation is closely related to the heat and moisture transfer of building envelope,so it is important to understand the transfer phenomena inside the building wall.One-dimensional unsteady heat,wet and air coupled transfer model (HAM) of the wall is founded,with relative humidity and temperature gradient being the driving force.And the finite element method is used to solve the numerical model.The numerical results show that the temperature fluctuation of the inner wall is small due to moisture transfer,but moisture would be accumulated in the transfer process,which lead to the wall service life reduce.The total heat transfer quantity of the wall considering moisture transfer increases 7.5％ compared with that ignore the mass transfer.The maximum of average number of inner wall surface with moisture transfer is 0.78 larger than that condition without mass transfer.