夏热冬冷地区外墙内保温热桥处理做法探讨

Study on the Heat Bridge Treatment of Interior Thermal Insulation of Exterior Wall in Hot Summer and Cold Winter Zone

外墙内保温热桥的处理影响墙体整体热工性能,现行国家或地方标准设计图集有针对建筑外墙内保温热桥相应的节点构造做法,但占用室内使用面积、影响室内装修等问题,导致外墙内保温体系在工程中应用受限.本文针对夏热冬冷地区气候条件,将外墙与内墙相交处T型热桥作为研究对象,通过对比分析两种工况下的热桥内表面最低温度及单位面积热桥附加热流量,从而确定在该地区外墙内保温热桥处理方式.模拟结果表明,翻边时热桥内表面最低温度为13.7℃,单位面积热桥附加热流量为1.830 W/m^(2);不翻边时热桥内表面最低温度为14.1℃,单位面积热桥附加热流量为3.986 W/m^(2),两种工况的热桥附加热流量的绝对值较小,且内表面均不会产生结露现象,若同时满足外墙平均传热系数小于节能标准规定值,内墙可不做翻边保温处理.

Thermal bridge treatments of interior thermal insulation on external walls will influence the thermal performance of the entire building envelope. Although there are corresponding construction practice of joints aiming at thermal bridges in interior thermal insulation on external walls in existing national or local standard design atlas,it is restricted in engineering to apply interior thermal insulation system on external walls due to the problems of occupying indoor usable area,affecting interior decoration and so forth. This paper studied on the thermal bridge of‘T’shape in intersecting joints between external walls and inner partitions under the climate conditions of hot summer and cold winter zone. Comparing and analyzing the lowest temperature on internal surfaces and the additional heat flow per unit area of thermal bridges under two scenarios,the thermal bridge treatment was determined for interior thermal insulation on external walls in this climatic zone. The simulation results show that with flanging of the thermal insulation layers,the lowest temperature on internal surfaces of thermal bridges is 13.7℃ and the additional heat flow per unit area of thermal bridges is 1.830 W/m2,while without flanging of the thermal insulation layers,the parameters reach 14.1 ℃ and 3. 986 W/m2 respectively. The absolute values of the additional heat flow per unit area of thermal bridges are relatively low under the two scenarios and dewing on the internal surfaces would not occur in both. In addition,the internal partitions can be designed and constructed without flanging of the thermal insulation layers when the average heat transfer coefficient of external walls is proved lower than the specified value in design standard for energy efficiency.