纵向风速对隧道细水雾灭火效果影响探讨  

Discussion on influence of longitudinal wind speed on fire extinguishing effect of water mist system in tunnel

作　　者：张奥宇 邓敏[1,2] ZHANG Ao-yu;DENG Min(China Communication Second Highway Consultant Company,Hubei Wuhan 430000,China;Wuhan China Communication Transportation Engineering Company,Hubei Wuhan 430000,China)

机构地区：[1]中交第二公路勘察设计研究院有限公司,湖北武汉430000 [2]武汉中交交通工程有限责任公司,湖北武汉430000

出　　处：《消防科学与技术》2022年第6期792-796,共5页Fire Science and Technology

基　　金：中交建重大科研项目(KJFZ-2019-086);建宁西路过江通道地下互通工程运营通风及烟气控制模型试验研究(JNXL-2019-Z010)。

摘　　要：为了探究细水雾和纵向通风共同作用下隧道内烟气运动情况,确定配置有细水雾灭火系统的隧道最佳通风策略。采用FDS建立了隧道细水雾数值模拟模型,分别计算了不同纵向风速情况下隧道内温度、有害气体浓度及辐射热通量的变化情况。结果表明:30 MW火灾规模下,烟气层在火源上风向15 m的喷雾区开始出现逐渐层降,烟气层下降至2 m以下;至300 s灭火结束时,上风向150 m内,烟气层全部下降至2 m以下。故火灾发生5 min后,人员疏散距离应大于150 m。对比相同通风风速下(1 m/s)细水雾施加前后辐射热通量变化情况得出,开启细水雾灭火系统25 s后,火源下游5 m处热辐射强度由6 kW/m;降至0。建议开启细水雾灭火系统时尽量保持隧道内1 m/s的通风风速。In order to research smoke movement under water mist firefighting system and longitudinal ventilation,consequently,ensure best ventilation strategy under water mist firefighting system.A serious of numerical simulation model was conducted with fire dynamics simulator,and the change of temperature,carbon monoxide concentration and radiant heat flux under different longitudinal wind speeds were obtained.The results show that:under the fire scale of 30 MW,the smoke layer begins to gradually drop in the spray area 15 m upwind from the fire source,and the smoke layer drops below 2 m;when the fire is extinguished in 300 s,within 150 m upwind,the smoke layer all dropped below 2 m.Therefore,5 minutes after the fire broke out,the evacuation distance of personnel should be greater than150 m.Comparing the changes of radiant heat flux before and after the application of water mist under the same ventilation wind speed (1 m/s),it can be concluded that after the water mist fire extinguishing system is turned on for 25 s,the heat radiation intensity at 5 m downstream of the fire source decreases from 6 kW/m~2to 0.It is recommended to keep the ventilation wind speed of 1 m/s in the tunnel as much as possible when turning on the water mist fire extinguishing system.

关 键 词：桥梁与隧道工程 隧道火灾 细水雾灭火系统 数值模拟 纵向通风 

分 类 号：U458.1[建筑科学—桥梁与隧道工程] X951[交通运输工程—道路与铁道工程]