挑檐和窗槛墙阻止火灾竖向蔓延性能的数值模拟分析

The performance analysis and numerical simulation on horizontal projection and spandrel in preventing fire vertical spread

为了阻止室内火灾通过窗户等开口沿着建筑外墙竖向蔓延 ,我国的防火设计规范规定需要设置一定高度的实体裙墙或窗槛墙 ,但在某些建筑中如落地玻璃窗的建筑通常采用一定长度的挑檐来代替实体裙墙或窗槛墙。运用 FDS模型对设置挑檐和设置实体裙墙建筑进行数值模拟 ,然后分析与比较计算结果 ,认为在防火性能上设置挑檐比设置实体裙墙或窗槛更合理 。

In order to prevent the fire spreading vertically along external walls form the openings such as windows,solid skirt-walls or spandrels were prescribed in fire protecting code of our county.In some buidings such as French window building,the spandrels were replaced by horizontal projection with a certain length.In this paper,numerical simulations on horizontal projection and spandrel were performed by using FDS(Fire Dynamics Simulator)model at first,and then calculated data were analyzed and compared.Finally,conclusions have been given that spandrel was more reasonable than horizontal projection in fire prevention function,and had a more availability to prevent fire from spreading vertically.