广西居住建筑围护结构线性热桥数值模拟研究

Numerical Simulation of Linear Thermal Bridge for Residential Building Envelope in Guangxi

为研究广西居住建筑不同保温方式的线性热桥对围护结构热工性能的影响,以某剪力墙结构的住宅建筑为例,应用BECS节能设计软件,对典型线性热桥的线传热系数和案例建筑的外墙热工性能进行数值模拟和分析。结果表明,线性热桥对墙体传热的影响显著,在外墙平均传热系数中因线性热桥所致的外墙平均传热系数分项约占1/3;当外墙采用内保温时,外墙与内墙、外墙与垂直外挑楼板部位的线传热系数最大,其次是外墙与楼板、外墙与水平外挑楼板部位;当外墙采用外保温时,外墙与垂直外挑楼板部位的线传热系数最大,其次是门窗上口、下口、左右口及外墙与水平外挑楼板部位。同时发现,不同保温方式的线性热桥对外墙平均传热系数的影响程度不同,内保温方式的线性热桥对外墙平均传热系数的影响高于外保温;且保温材料越厚,线性热桥对外墙平均传热系数的影响越大。

In order to study the influence of linear thermal bridge with different thermal insulation methods on the thermal performance of the envelope of residential buildings in Guangxi,taking a residential building with shear wall structure as an example,the linear heat transfer coefficient of typical linear thermal bridges and the thermal performance of the external wall of the case building were numerically simulated and analyzed by using the BECS energy-saving design software.The results show that the linear thermal bridge has a significant effect on the heat transfer of the wall,and the proportion of the average heat transfer coefficient of the external wall caused by the linear thermal bridge is nearly one third.When the external wall adopts internal insulation,the linear heat transfer coefficient at the junction of external wall and internal wall,and the junction of external wall and vertical overhanging floor is the largest,followed by the junction of external wall and floor,and the junction of external wall and horizontal overhanging floor;When external insulation is used for external wall,the linear heat transfer coefficient at the junction of external wall and vertical overhanging floor is the largest,followed by the upper,lower,left and right openings of doors and windows,and the junction of external wall and horizontal overhanging floor.Meanwhile,it is found that the linear thermal bridge with different insulation methods has different influence on the average heat transfer coefficient of the external wall,and the linear thermal bridge with internal insulation method has higher influence on the average heat transfer coefficient of the external wall than that with external insulation;And the thicker the insulation material,the greater the influence of the linear thermal bridge on the average heat transfer coefficient of the exterior wall.