XPS外保温系统竖向火蔓延大涡模拟与危险性分析  

Large-eddy Simulation and Risk Analysis on Upward Fire Spread of XPS Exterior Insulation System

作　　者：张国维[1] 朱国庆[1] 黄丽丽[1,2] 

机构地区：[1]中国矿业大学安全工程学院,江苏徐州221008 [2]广州中国科园院工业技术研究院,广东广州510000

出　　处：《应用基础与工程科学学报》2013年第5期973-982,共10页Journal of Basic Science and Engineering

基　　金：江苏省自然科学基金面上项目(BK20131117);住房和城乡建设部科学技术项目(2011-K1-53)

摘　　要：对XPS外保温系统竖向火蔓延问题,提出了基于XPS保温板燃烧特性实验数据的大涡模拟方法.实验获得了XPS保温板燃点、燃烧热值以及热流作用下的质量损失速率.基于实验数据,以某七层住宅建筑为例,采用大涡模拟方法研究了XPS保温板竖向火蔓延的火灾危险性,分析了竖向火焰前锋蔓延速度,火场烟气温度、烟气能见度及烟气毒性等危险性指标.研究结果表明,辐射热流作用下XPS保温板质量损失呈现平缓热解阶段、急剧骤减阶段和相对稳定阶段,其中质量骤减阶段质量呈明显的线性变化.保温板竖向火焰前锋位置为时间的幂函数,竖向火焰蔓延速度远大于水平火焰蔓延速度.外立面保温板燃烧火焰通过门窗洞口窜入室内,引发建筑立体式火灾.过火房间内温度超过600℃,存有发生轰燃的可能性,起火点以上楼层火灾危险性随楼层高度成递减趋势.Large-eddy simulation based on experimental data was proposed to study the upward fire spread of Expanded Polystyrene （XPS） exterior insulation system. Groups of experiments were conducted to study ignition temperature, combustion heat and mass loss rate of XPS board firstly. With the help of experimental data, a large-eddy simulation on upward fire spread and risk analysis was made to study fire spread rate, smoke temperature, smoke visibility and CO content in a seven-story building＇ exterior insulation system fire. The study showed that mass loss rate in the experiment had three stages：slow pyrolysis stage, rapid reduction stage and relatively stable stage and that mass of XPS boards decreased linearly during the rapid reduction stage. Flame front position could be expressed as a power function of time while flame spread faster in vertical direction than that in horizontal direction. Meanwhile fire spreading on the building＇ exterior insulation could flow into room through vents. There is possibility of flashover indoor for the smoke temperature exceeds 600℃ in room. The danger approaches time away from the fire sources increase with the floor height

关 键 词：XPS板 大涡模拟 火灾危险性 竖向火蔓延 

分 类 号：X4[环境科学与工程—灾害防治] TU998.1[建筑科学—市政工程]