公路隧道细水雾与纵向通风作用下的火灾烟气输运特性与控制方法研究

The tunnel is a long and relatively closed narrow space, once the tunnel fire happens, the heat smoke generated and spread quickly in the tunnel, and reduce the visibility, that cause the people evacuation and rescue difficulty. Extinction of fire and control of smoke spread is the important way to reduce the loss of tunnel fire accidents. Water mist is used widely for suppressing fires in tunnels, due to no due to high fire extinguishing effectiveness, safety to human and equipment, no pollution, etc. In this study, based on the scale model tests of tunnel ventilation for fire, the theoretical analysis, the numerical analysis and analysis of field data are adopted to investigate the following issues: under combined action of water mist and longitudinal ventilation, analysis the characteristics of fire plumes, ceiling jet flows and fire smoke transport in tunnel characteristics of tunnel fire, analysis the influence of water mist fire suppression system and longitudinal ventilation system on the ratio of air entrainment into the plumes, the temperature profiles of ceiling jet flows and the characteristic parameters of fire smoke transport, discussing the main mechanism of controlling fire smoke spreading by water mist and longitudinal ventilation; presenting the fire smoke control strategy in tunnel with water mist fire suppression system and longitudinal ventilation system. It is expected that this study will extend the application of water mist in extra-long tunnel, reduce the tunnel fire damage, and provide the scientific basis for fire smoke control strategy in tunnel with water mist fire suppression system and longitudinal ventilation system.

隧道内一旦发生火灾，大量高温有毒烟气迅速蔓延，人员疏散救援难度大，危害极大，有效抑制火灾发展、控制烟气蔓延是减小火灾事故损失的重要途径之一。细水雾灭火技术因其能够迅速抑制扑灭火灾、对环境影响小的特点，在公路隧道中获得推广。本项目以隧道细水雾作用下的火灾通风物理模型试验为基础，结合理论分析、数值模拟和现场实测数据分析等研究手段，分析隧道细水雾与纵向通风作用下的火灾顶棚射流与火羽流行为特性、火灾烟气输运特性，研究不同细水雾与纵向通风系统设计参数影响下的，隧道内火羽流卷吸系数、顶棚射流温度分布、烟气输运特征参数的变化规律，探讨隧道细水雾与纵向通风共同作用下，抑制熄灭火灾、减小烟气生成、抑制烟气流动的机理，提出隧道细水雾与纵向通风作用下的火灾烟气控制方法。研究成果预期可以进一步推动细水雾技术在隧道运营安全领域的应用，减小火灾损失，为具备细水雾自动灭火系统的隧道的火灾烟气控制提供理论依据。

隧道内一旦发生火灾，大量高温有毒烟气迅速蔓延，人员疏散救援难度大，危害极大，有效抑制火灾发展、控制烟气蔓延是减小火灾事故损失的重要途径之一。细水雾灭火技术因其能够迅速抑制扑灭火灾、对环境影响小的特点，在公路隧道中获得推广。然而，细水雾系统与纵向通风共同作用于隧道火灾时，水雾与烟层发生热量、质量以及动量交换，影响了烟层输运特性与烟气控制。本项目以隧道细水雾作用下的火灾通风物理模型试验为基础，结合理论分析、数值模拟分析等研究手段，解决了如下关键问题：1）分析了细水雾与纵向通风共同作用对隧道火灾拱顶温度分布的影响规律，明确了顶棚射流的发展规律，建立了拱顶温升预测模型；2）阐明了细水雾与纵向通风共同作用对隧道火灾烟气流动特性的影响机制，建立了不同细水雾设计参数与纵向风速组合下烟气逆流长度与温度的量化关系、临界风速与火源上方最高温度的量化关系；3）提出了隧道火灾细水雾与纵向通风组合设计参数与火灾烟气控制措施。研究成果在一定程度上丰富了隧道火灾防控理论研究，推动了细水雾自动灭火系统在公路隧道运营安全领域的应用，为优化隧道消防系统设计应用以及提高运营安全性提供理论支撑。本研究项目成果在国家青基资助下共发表期刊论文7篇，培养研究生3名。