特长公路隧道群火灾烟气特性及通风方式研究

Study on Fire Smoke Characteristics and Ventilation Mode of Extra-long Highway Tunnel Group

为解决特长隧道群通风排烟难题,先对整个隧道群的需风量进行计算,后采用FDS软件建立特长隧道火灾场景三维数值模型,分析了特长隧道群全纵向排烟及分段式排烟的烟雾运动规律,提出了北中山1号、2号隧道需采用全纵向射流风机+辅助排烟通道的分段排烟方案;再通过结构形式、施工难度、工程造价等因素对北中山1号、2号隧道分段式排烟方案进行比选,获得最优方案。结果表明:1)采用分段排烟方式能较好地将火灾烟气控制在火源下游,保障隧道上游疏散安全;2)影响隧道纵向通风的主要因素是隧道纵坡及长度,对于下坡隧道,换气工况起主要控制作用,对于上坡隧道,80 km/h的运营工况起主要控制作用;3)考虑多因素比选分析后得出了较优通风方案,北中山1号隧道采用全纵向+平导+地上风机房方案,北中山2号隧道采用全纵向+竖井+地下风机房方案。研究结论可为类似工程提供借鉴和参考。

In order to solve the problem of ventilation and smoke exhaust in extra-long tunnels,a three-dimensional numerical model of fire scene in extra-long tunnels was established by FDS software through the calculation of tunnel air demand.The smoke movement law of full longitudinal smoke exhaust and segmented smoke exhaust in extra-long tunnels was analyzed,and a segmented smoke exhaust scheme of full longitudinal jet fan+auxiliary smoke exhaust channel was proposed for the Beizhongshan No.1 and No.2 tunnels.Then,the scheme of segmented smoke exhaust in the Beizhongshan No.1 and No.2 tunnels is compared.Finally,an optimal scheme is obtained through structural form,fan configuration,construction difficulty,project cost and other factors.The results show that:1)The segmented smoke exhaust method can effctively control the fire smoke downstream of the fire source and ensure the evacuation safety upstream of the tunnel.2)The main factors affecting the longitudinal ventilation of the tunnel are the longitudinal slope and length of the tunnel.For the downhill tunnel,the ventilation condition plays a major control role.For the uphill tunnel,the operating condition of 80 km perhour plays a major control role.After comparison and analysis.3)Considering multi factors,a better ventilation scheme is obtained.Beizhongshan No.1 tunnel adopts the scheme of full longitudinal+horizontal guide+ground fan room,and Beizhongshan No.2 tunnel adopts the scheme of full longitudinal+shaft+underground fan room.The research conclusions can provide reference for similar projects.