车窗开闭状态对双层列车车厢内火灾烟气特性的影响

车窗开闭状态对列车火灾影响较大,而在现有研究中,对双层列车火灾烟气特性研究较少。基于计算流体动力学理论(Computational dynamics theory, CFD),建立双层列车单节车厢的火灾数值计算模型,采用大涡模拟方法(Large eddy simulation,LES)对车内流场进行数值模拟。在火源位置、火源功率以及列车运行速度等参数不变的条件下,研究不同位置车窗的开闭状态对双层列车上下两层车厢内烟气特性的影响。结果表明,打开不同位置的车窗对车厢内烟气特性影响较大;打开火源前方的车窗使双层列车整节车厢的烟气层高度升高、CO浓度降低、烟气温度下降,车厢内烟气向有利于乘客逃生的方向发展;打开火源后方的车窗只降低车厢后部区域CO浓度和烟气温度,烟气层高度升高。根据研究结果,为双层列车逃生疏散设计提供参考。

Influence of Open and Closed Window on Fire Smoke Characteristics in Double-decker Trains

The window opening and closing state has a greater impact on train fires, and in existing studies, there are few studies on the smoke characteristics of double-decker trains. Based on the computational fluid dynamics theory(CFD), the fire numerical calculation model of the double-layer train is established, and the large eddy simulation method(LES) is used to numerically simulate the flow field in the vehicle. By setting parameters such as fire source position, fire source power, and train running speed unchanged, only changing the parameter of the window opening and closing state of the lower car of the double-decker train, studying the change of windows in different positions after a fire occurs during the train operation. The effect of the opening and closing state of the on the smoke characteristics of the upper and lower double-deck trains. Through research and analysis, it is found that opening the windows in different positions has a greater impact on the smoke characteristics in the car: Opening the window in front of the fire source causes the height of the smoke layer of the entire train of the double-decker train to increase, the CO concentration decreases, and the temperature of the smoke When it descends, the smoke in the carriage develops in a direction that is conducive to passenger escape. Opening the window behind the fire source only reduces the CO concentration and smoke temperature in the rear area of the cabin, and the height of the smoke layer increases. According to the research results, it provides a reference for the escape and evacuation design of double-deck trains.