地铁作为一种重要的城市交通方式，具有客运量大、快速安全、准时可靠、低碳环保等优点，已成为缓解城市交通堵塞的重要手段。在地铁日常运营中，火灾是后果最严重的安全事故。目前，《地铁车辆运营技术规范》中规定“列车接受到内部火灾报警信号后，在确保安全的情况下，根据火灾位置、火势大小及蔓延程度可采取关闭部分车辆的空调机组等措施”，但“部分车辆的空调机组”的说法仍存在模糊。着火车厢与非着火车厢间的贯通相连导致火灾时列车内的烟气流动受空调系统运行模式的影响很大，进而影响人员向相邻车厢的疏散的安全性。本文研究了地铁列车空调及排烟系统对车内火灾烟气流动及人员疏散安全性的影响，对于提升火灾时人员的安全性具有重要意义。
论文首先基于相似准则，搭建了缩尺比为1:2的地铁车辆火灾缩尺实验台，采用热烟的试验方法，研究了着火车厢内空调运行对车厢内烟气流动及温度分布的影响规律。实验结果表明，在EN45545点火模式5的火源荷载下，空调运行时沿顶板蔓延的烟气层被破坏，非火源区域烟气浓度下降、温度降低，车厢端部温度降低在20 ℃以上，紧急通风模式对车厢内的冷却作用弱于全新风空调模式。
其次，建立了三节车厢组成的地铁列车火灾数值计算模型，研究了空调运行对列车火灾蔓延影响。研究结果表明：行李起火情况下，旧式地铁与新型地铁中火灾都无法蔓延，不同车厢空调运行时火灾发展过程一致。发生人为纵火时，装载了阻燃材料的新型地铁车厢在防火性能方面得到了显著提升，火灾无法在车厢内蔓延，空调运行对着火车厢内火灾发展过程影响较小。旧式地铁发生人为纵火时，车厢内火灾发生蔓延，最大热释放速率可达6 MW。相邻车厢空调运行对着火车厢内火灾蔓延影响较小，火灾热释放速率与空调系统关闭时变化一致。着火车厢内空调运行时，空调送风促进了车厢内火灾的蔓延，空调送风时火灾热释放速率更大且增长的更快，两者最大差值为450 kW。
然后，通过数值模拟研究了列车空调运行模式和排烟运行模式对烟气流动的影响。研究结果表明：行李起火和人为纵火时，相邻车厢空调运行对着火车厢内烟气流动的影响较小。相邻车厢空调运行有利于减小烟气的蔓延范围，烟气主要集中在着火车厢内，降低了相邻车厢内温度和烟气毒性且提高了相邻车厢内的能见度。行李起火时，着火车厢内空调运行状态为全新风空调模式时可降低除火源区域外的温度和烟气浓度，紧急通风模式对烟气的冷却和稀释作用弱于空调模式。相邻车厢空调与着火车厢机械排烟运行有利于控制烟气的流向和分布，高温烟气主要集中在着火车厢内部。
最后，对行李起火时列车空调和排烟运行对人员疏散的影响进行了数值模拟研究，根据列车空调系统和排烟系统的不同运行状态下的可用的疏散时间，制定了列车内火灾烟气的控制策略。研究结果表明：相邻车厢空调运行能够提高相邻车厢人员在疏散过程中的安全性。相邻车厢空调和着火车厢排烟运行时，整个列车内人员的安全性均得到提升。列车内火灾烟气的控制策略为：在车厢内发生火灾时，非着火车厢空调应保持开启并处于全新风模式，着火车厢内应开启机械排烟并关闭空调系统。

As an important urban transportation mode, subway has the advantages of large passenger volume, fast and safe, punctual and reliable, low carbon and environmental protection, and has become an important means to alleviate urban traffic congestion. In the daily operation of subway, fire is the most serious safety accident. At present, the "Technical Specifications for the Operation of subway vehicles" stipulates that "after the train receives the internal fire alarm signal, in the case of ensuring safety, measures such as closing the air conditioning unit of some vehicles can be taken according to the location of the fire, the size of the fire and the extent of the spread of the fire", but the "air conditioning unit of some vehicles" is still vague. Due to the connection between the burning car and the non-burning car, the smoke flow in the train during the fire is greatly affected by the operation mode of the air conditioning system, which further affects the safety of personnel evacuation to the adjacent car. In this paper, the influence of air conditioning and smoke exhaust system on fire smoke flow and personnel evacuation safety in subway trains is studied, which is of great significance for improving the safety of personnel during fire.
Based on the similarity criterion, a scale scale test platform with a scale ratio of 1:2 was set up to study the effect of air conditioning operation on smoke flow and temperature distribution in a burning car. The experimental results show that under the fire source load of EN45545 ignition mode 5, the smoke layer spreading along the roof is destroyed, the smoke concentration and temperature in the non-fire source area are reduced, and the temperature at the end of the carriage is reduced to more than 20 ℃. The cooling effect of the emergency ventilation mode on the carriage is weaker than that of the full fresh air air-conditioning mode.
Secondly, the numerical calculation model of subway train fire composed of 3 cars is established, and the influence of air conditioning operation on train fire spread is studied. The results show that, in the case of luggage fire, the fire can not spread in the old subway and the new subway, and the fire development process is the same when the air conditioning is running in different carriages. In the event of arson, the new subway cars loaded with flame retardant materials have been significantly improved in terms of fire performance, the fire cannot spread in the car, and the air conditioning operation has little impact on the fire development process in the burning car. When arson occurs in the old subway, the fire in the carriage spreads, and the maximum heat release rate can reach 6 MW. The air conditioning operation of adjacent car has little effect on the fire spread in the burning car, and the fire heat release rate changes the same as when the air conditioning system is closed. When the air conditioner is running in the burning car, the air supply of the air conditioner promotes the spread of the fire in the car, and the fire heat release rate is larger and grows faster when the air conditioner is supplying the air. The maximum difference between the two is 450 kW.
Then, the effects of air conditioning operation mode and smoke exhaust operation mode on smoke flow were studied by numerical simulation. The results show that the air conditioning operation of adjacent cars has little effect on the smoke flow in the luggage fire and arson. The operation of air conditioning in adjacent compartments is conducive to reducing the spread of smoke, which is mainly concentrated in the burning compartment, reducing the temperature and smoke toxicity in adjacent compartments and improving the visibility in adjacent compartments. When the baggage is on fire, the air conditioner operating in the air conditioner mode can reduce the temperature and smoke concentration except the fire source area. The cooling and dilution effect of the emergency ventilation mode on the smoke is weaker than that of the air conditioner mode. The operation of air conditioning in adjacent cars and mechanical smoke exhaust in burning cars is conducive to controlling the flow direction and distribution of smoke, and the high-temperature smoke mainly concentrates in the interior of burning cars.
Finally, the effect of air conditioning and smoke exhaust operation on the evacuation of passengers is simulated numerically. According to the available evacuation time of air conditioning system and smoke exhaust system, the control strategy of fire smoke in train is developed. The results show that the air conditioning operation of adjacent compartments can improve the safety of adjacent compartments in the evacuation process. When air conditioning in adjacent cars and smoke exhaust in burning cars operate, the safety of personnel in the whole train is improved. The control strategy of fire smoke in the train is as follows: in case of fire in the train, the air conditioning in the non-burning car should be kept on and in the full fresh air mode, and the mechanical smoke exhaust system should be turned on and the air conditioning system closed in the burning car.