凹廊式高层建筑火灾烟气蔓延数值模拟分析

Numerical simulation analysis on fire smoke spread in high-rise buildings with corridor structure

以某火灾事故建筑为原型,运用FDS模拟凹廊式高层建筑火灾的蔓延过程,对比室外凹廊处和室内起火的条件下烟气蔓延情况,分析凹廊处起火烟气蔓延速度、温度、遮光率和烟气的质量浓度等参数的变化以及有无主导风向对火灾蔓延的影响。结果表明:烟气垂直方向蔓延速度表现为距离着火点越近速度越快;有凹廊设计的高层建筑更易形成"烟囱效应",加速火势蔓延,应提高凹廊处耐火限度,增加防火、防烟设施;凹廊式建筑设计施工中应对主导风向的下风向一侧提升耐火限度。

Taking the building of a fire accident as the prototype, FDS was used to simulate the spread process of high-rise building fire with corridor structure.Comparative analysis on the smoke spread of the outdoor corridor structure fire and indoor fire,changes in parameters such as fire smoke spread speed,temperature, shading rate,and smoke mass concentration at the alcove were analyzed,and the spread of fire with and without dominant wind direction was analyzed too.The results showed that:the closer to the ignition point,the faster the fire smoke spreads vertically.High-rise buildings with a corridor design are more likely to form a "chimney effect"and accelerate the spread of fire.Therefore,the fire resistance lhnit at the structure of the corridor should be increased,and fire prevention and smoke prevention facilities should be added. During the design and construction of a building with a corridor structure,the fire resistance limit at downwind side of the dominant wind should be raised.