寒冷地区外保温墙体热湿耦合特性

为了研究外保温墙体非稳态热湿耦合传递规律，降低墙体内部受潮的危害，以寒冷地区保定市典型的外保温墙体为研究对象，针对以现浇混凝土为基层和以轻质砌块为基层的外墙外保温系统，通过模拟对它们的热湿传递特性进行横向对比研究。同时从隔汽层的设置与空气层安装这两方面，分析其对墙体热湿性能的影响。模拟结果表明：在寒冷地区冬季工况下，现浇混凝土墙体保温层受潮位置在靠近室外一侧，轻质砌块墙体保温层受潮位置主要在保温层中间及靠近基层墙体一侧，其中轻质砌块墙体的保温层受潮程度较为严重，保温层的最大相对湿度达到71.5%且长期高于室外环境相对湿度，容易发生湿积累。安装隔汽层后，轻质砌块系统保温层含水量下降了17.3%，保温层相对湿度下降到50%以下。安装空气层后，现浇混凝土系统的热阻提高，采暖期最冷日墙体平均温度上升了2.88 ℃，采暖期保温层最高相对湿度下降到了34%，但会增加夏季保温层的相对湿度，综合效果不佳。

Research on Coupled Heat and Moisture Transmission Characteristics of Exterior Thermal Insulation System in Cold Regions

In order to study the unsteady heat and humidity coupling transfer law of external thermal insulation walls and reduce the harm of moisture inside the walls, the typical external thermal insulation walls in Baoding City, cold areas were taken as the research object, and the exterior wall external insulation systems with cast-in-place con-crete as the base layer and lightweight blocks as the base layer were compared horizontally by simulation. At the same time, from the two aspects of the setting of the vapor barrier layer and the installation of the air layer, the influence on the thermal and humid performance of the wall was analyzed. The simulation results show that, un-der winter conditions in cold regions, the cast-in-place concrete wall insulation layer is affected by moisture on the side near the outdoor, and the lightweight block wall insulation layer is mainly affected by moisture in the middle of the insulation layer and on the side near the base wall. The latter is seriously affected by moisture, and the maximum relative humidity of the insulation layer is 71.5% which is higher than the outdoor ambient relative humidity for a long time. After installing the vapor barrier, the moisture content of the insulation layer of the lightweight block system decreased by 17.3%, and the relative humidity of the insulation layer dropped to less than 50%. After installing the air layer, the thermal resistance of the cast-in-place concrete system increased, the average temperature of the wall on the coldest day of the heating period increased by 2.88 °C, and the maximum relative humidity of the insulation layer during the heating period decreased to 34%, but the relative humidity of the summer insulation layer was increased, and the comprehensive effect was not good.