【作者】 孟娜；

【导师】 杨立中； 胡隆华；

【作者基本信息】 中国科学技术大学 ， 安全科学与工程， 2014， 博士

【摘要】 随着城市的不断发展,地铁应运而生。地铁的出现极大的解决了城市的交通拥堵问题,然而自地铁出现以来,地铁火灾便不可避免。研究表明地铁发生火灾时,火灾烟气是威胁人员安全的主要原因。地铁火灾可发生在站厅层、站台层和行驶中的列车上。站厅层发生火灾时,由于站厅层直接与地面相连,因此,人员疏散和火灾救援相比站台层火灾和列车火灾相对容易一些。站台层发生火灾时,站台层的人员往往通过站厅与站台之间连通的楼梯或自动扶梯疏散至站厅层,因此,站台火灾时站台与站厅关键结合部位的烟气流动与控制研究非常重要。行驶中的地铁列车发生火灾时,由于在隧道内不利于火灾扑救和人员疏散,因此应尽量行驶至前方车站停靠站台进行火灾扑救和人员疏散。着火列车停靠车站时,列车车门和站台屏蔽门均处于打开状态,隧道轨行区和站台区处于连通状态,火灾烟气会由隧道轨行区向站台区蔓延,因此,研究此火灾场景下烟气在隧道和站台关键结合部位的流动特性具有重要意义。对于地铁列车火灾的扑救,越来越多的研究者想把细水雾系统应用于地铁火灾扑救中,细水雾在火灾扑救中将受隧道纵向风的影响,因此,细水雾和纵向风都会对烟气流动产生影响。现阶段地铁车站往往设有多套烟气控制系统,那么列车火灾停靠车站时,车站多套烟气控制系统的协同优化工作模式也需要进一步深入研究。本文针对地铁车站火灾时车站关键结合部位烟气流动特性与控制模式优化采用实验研究、理论分析和数值模拟的方法开展研究。建立了1：10模拟尺度的地铁车站烟气控制实验台和全尺寸列车火灾模拟实验台,通过对火灾时烟气流动的特征参数温度、有毒气体浓度等参数的测量,揭示了地铁站火灾时烟气在关键结合部位的流动特性,并提出了优化的烟气控制模式。具体工作包括：研究了站台火灾时,站台到站厅关键结合部位挡烟垂壁的设置对站台顶棚烟气温度分布的影响。通过理论分析,建立了站台火灾时顶棚温度衰减指数与火源功率和挡烟垂壁高度之间的耦合关系模型,并通过开展小尺寸实验对该模型进行了验证。研究了列车火灾停靠车站时,火灾烟气在隧道和站台关键结合部位的流动特性。通过在小尺寸实验台开展实验,揭示了车站烟气控制系统失效情况下,隧道区烟气温度衰减规律,以及火源位置和火源功率对站台区温度分布的影响。研究了列车火灾停靠车站时,在细水雾和纵向风耦合作用下,火灾烟气在隧道和站台关键结合部位的蔓延特性。通过在全尺寸实验台开展实验,揭示了火源位于不同位置时,细水雾和纵向风的耦合作用下,隧道区和站台区的能见度、温度场以及CO有毒气体浓度的分布特性。研究了列车火灾停靠地铁车站时,车站多套烟气控制系统的协同优化工作模式。通过数值模拟的方法,对全封闭式屏蔽门和半高安全门两种设置形式的地铁车站多套烟气控制系统组合模式下的烟气控制效果进行对比分析,提出了优化的烟气控制模式。模拟还对车站关键结合部位辅助烟气控制设施的设置形式优化开展了研究。更多还原

【Abstract】 With the continuous development of cities, subway emerged as the times. The traffic problem in cities has been solved greatly since the appearance of subway. However, since subway come into being, subway fire has been inevitable. Studies have shown that in case of a fire at subway, the main threat to personnel safety is smoke. Fires at subway station might occur at the lobby floor, at the platform floor or in the moving train. In case of a fire at the lobby floor, because the lobby floor and the ground are directly connected, personnel evacuation and fire rescue might be easier in comparison with fires at the platform floor or in the travelling train. When a fire happens at the platform floor, passengers there usually go through the stairs or escalators to the lobby floor. Therefore, studies on the smoke movement and its corresponding control at conjunction areas between the platform floor and the lobby floor are very important. When a travelling train is on fire, as it is not convenient to carry out fire-fighting and personnel evacuation in the tunnel, the train should better move to the subway station in front and stops for fire rescue. When a train stops at the subway station, doors of the train and the platform screen doors are all open, so the tunnel rail track space and the platform area are connected in space. Smoke can spill out of the train carriage and propagates in the tunnel and the platform area, so, it is of great importance to investigate the smoke flowing characteristics at key conjunction areas between tunnel and platform. As for the fire fighting for train fire, more and more researchers try to employ the water mist system in fire-fighting at subway station. The performance of the water mist system is also affected by the longitudinal ventilation during its fire suppression in tunnels; as a result, smoke flowing can be influenced both by water mist and longitudinal ventilation. At present, multiple smoke control systems are set at subway station, so for train on fire stopping at subway station, the optimization of the multiple smoke control modes also needs to be further investigated.In this paper, the smoke flowing characteristics and its corresponding smoke control mode optimization at conjunction areas of subway station are studied based on experimental research, theoretical analysis and numerical simulation methods. A1:10scale model experimental facility for smoke controlling at subway station and a full scale experimental facility for train fire simulation are established. Based on the measurement of smoke flowing characteristic parameters, such as temperature, toxic gas concentration, et.al, the smoke flowing characteristics at key conjunction areas of subway station are revealed, and optimized smoke control mode is proposed. The specific work is as follows:For platform fire, the influence of the installation of smoke screen at the key conjunction areas between platform floor and lobby floor on the platform ceiling temperature distribution is studied. A scaling correlation is proposed to characterize the smoke temperature decay index by heat release rate and smoke screen height. A series of small-scale experiments are carried out to verify this model.The smoke flowing characteristics between key conjunction areas between the tunnel and the platform is studied in case of a train on fire stopping at subway station. Experiments are conducted in the scale model facility as to study the smoke distribution in the tunnel and at the platform floor when the smoke control systems are all deactivated. The smoke temperature decay law in the tunnel is revealed, and the effects of fire position and fire heat release rate on the temperature distribution at the platform floor are also presented.The smoke flowing characteristics at key conjunction areas between tunnel and platform are also studied under the coupling effects of water mist and longitudinal ventilation when a train on fire stopping at subway station. Based on full-scale experiments, the visibility, temperature distribution, and CO distribution characteristics are revealed when fires are placed at different positions.When a train on fire stops at subway station, the optimization of the smoke control mode is investigated. Based on numerical simulation, comparative analysis are carried out to study the smoke control effects when multiple smoke control modes are employed at subway stations with full-seal platform screen door or half-height safety door. Optimized smoke control modes are put forward respectively for subway stations with full-seal platform screen door or half-height safety door. Numerical simulation is also carried out to study the optimization of the installation of the auxiliary smoke control facilities at conjunction areas at subway station.更多还原