考虑传湿时影响墙体传热系数的因素分析

Analysis of factors affecting heat transfer coefficient of walls under effects of moisture transfer

利用热湿耦合数学模型,通过数值计算分析不同因素时湿传递对围护结构的传热影响,并将该影响等效为对传热系数的修正。结果表明:传湿时围护结构传热系数随材料水蒸气渗透系数的增大而增大,随导热系数增大而减小。室外温度高于室内温度,传热系数修正幅度随室外气温升高而增大,反之减小。当室外气温低于室内时,传热系数随室外相对湿度的升高而增大;反之减小。室内外温湿度相差较大地区,更需考虑湿迁移对传热的影响。从减小湿传递和节能角度考虑,炎热潮湿地区宜采用内保温,传热系数比外保温时低约4.0%;寒冷干燥地区宜采用外保温,传热系数比内保温低约0.7%。

In order to analyze the effects of moisture transfer,heat transfer of building enclosure was evaluated under different factors by using coupled heat,moisture transfer mathematical model and numerical calculation.;It was equalized to the amendment of heat transfer coefficient.Results showed that the amendment of the heat transfer coefficient increased with the growth of the material＇s water vapor penetration coefficient,and decreased with the growth of coefficient of thermal conductivity.When outdoor temperature was higher than the indoor temperature,the amendment amplitude increased as outdoor temperature rose.Otherwise,it decreased.When outdoor temperature was lower than the indoor temperature,the heat transfer coefficient decreased with increasing outdoor relative humidity.Otherwise,it increased.In order to reduce moisture transfer and save energy,hot and humid regions may adopt internal insulation,and the heat transfer coefficient was about 4.0%lower than adopting exterior insulation.Cold and dry regions would adopt exterior insulation,and the heat transfer coefficient was about 0.7%lower than adopting internal insulation.