楼梯井内烟囱效应对着火房间燃烧和溢出烟气的影响研究  

Study on the influence of stack effect in stairwell on the compartment combustion and the spill Plume

作　　者：孙晓乾[1] 许兆宇[1] 胡隆华[1] 李元洲[1] 霍然[1] 

机构地区：[1]中国科学技术大学火灾科学国家重点实验室,安徽合肥230027

出　　处：《火灾科学》2009年第2期80-87,共8页Fire Safety Science

基　　金：中港合作裘措基金"高层建筑主动消防策略"(基金号:5-ZH46);国家自然科学基金(基金号:50676090)

摘　　要：实验研究了楼梯井内的烟囱效应对着火房间燃烧速率、补风速度、羽流温度等的影响。实验在一个模拟尺寸的十二层的楼梯井实验台内进行,实验时开启楼梯井顶层直通室外门。火灾时楼梯井内的烟囱效应加速了空气在楼梯井内的对流,使火源区从外界单侧卷吸空气,形成着火房间单侧强补风下的燃烧,燃烧速率比开放空间下的燃烧快,同时使得火焰向前室一侧倾斜,出现火焰"分岔"现象。与火源位于一层的工况相比,当火源位于六层,且首层门开启时,楼梯井内下部空气向上部烟气的掺混较大,着火房间门口进风速度减小,羽流的倾斜角度变小,温度较高,而当首层门关闭时,则减小了楼梯井下部空气与上部烟气的掺混,使得楼梯井内的上部烟气温度较高。Experiments were conducted in a scaled 12 - layer - stairwell configuration to study the effect of vertical stairwell on the compartment combustion. In experiments the stairwell was directly opened to outside through the door in the top floor. The burning rate of fuel, the entrainment rate, plume temperature were measured. It was observed that the air convection was enhanced by the stack effect in stairwell, which accelated the combustion in the compartment and made it burned faster than the free combustion, due to that the strong air was only supplied through the compartment door to outside. The stack effect also made the flame nearly tilted, and the air supplied to the combustion region separated the flame into two branches. The compartment combustion was also affected by the fire position and the ventilation conditions. Compared with the situation where the fire locates in the first floor, when fire was put in the sixth floor, and while the stairwell was opened to outside in the 1 st floor through the vest, it was observed that more air mixed into the smoke in the stairwell from below the 6th floor, and the the air supply velocity through the compartment door was reduced, the tilted plume had a relative small angle and a higher temperature. It was further observed that when the doors in the 1 st floor of stairwell were closed, the mixing between the air and smoke in the stairwell was reduced, and the smoke in the stairwell had a higher temperature.

关 键 词：高层建筑 楼梯井 烟囱效应 掺混 

分 类 号：TU[建筑科学]