公交车内火灾灭火实验及数值模拟研究

发布时间：2018-03-22 04:08

  本文选题：公交车　切入点：全尺寸实验　出处：《北京建筑大学》2017年硕士论文　论文类型：学位论文

【摘要】：近年来我国公交车火灾事件频发,对社会稳定和安全造成了极大的危害,因此对公交车火灾灭火进行研究十分必要。论文开展了对公交车火灾细水雾灭火的实验与模拟研究。理论分析了公交车火灾及灭火后烟气毒性的加权评价模型。火灾灭火实验在实体公交车内进行,在车厢内安装细水雾灭火系统,火灾采用油盘汽油火,进行了四种工况的火灾灭火实验。实验研究了公交车内细水雾灭火系统的灭火性能、火灾及灭火后车厢内温度分布、烟气毒性等问题。模拟研究了车厢内火灾及灭火后烟气流动的规律,具体分析了车窗不同开启位置、门窗开启时间和火源位置分别对车厢内温度、能见度和烟气流动的影响。通过分析公交车火灾的特点、火灾及灭火后烟气对人体的危害,分析比较了烟气毒性的FED模型和N-Gas模型两种加权评价模型。四种不同工况的实验研究得到灭火时间最短为4s,最长为9s。温度最高点出现在火源上方,最高温度为380℃,公交车顶部最高温度达到了230℃,中部最高温度达到了155℃,底部最高温度达到了65℃。O2最低含量降至17.9%,CO2最高含量达到了2.2%,CO最高浓度达到了424ppm,SO2最高浓度达到了45ppm,氮氧化物中只有NO,最高浓度为12ppm,碳氢化合物的最高浓度达到了373ppm。应用FED模型对CO进行分析,计算结果为0.024,在安全值0.1以内。应用N-Gas模型对实验烟气进行综合分析,计算值最大为0.2,小于安全值0.8。实验中的温度和烟气的毒性不会对车上人员造成生命危险。模拟研究发现车窗开启位置的不同对车厢内的能见度和烟气流动都有影响。车窗开启的区域烟气向外蔓延的较快,能见度较高。开启所有车窗的情况下,烟气排出外界的速度最快,开启灭火系统25s后车内能见度恢复到安全水平5m以上。门窗开启时间的不同对车厢内的温度和烟气流动都有影响。门窗开启的越早车内所达到的最高温度越大,但是越有利于烟气向外界排放。火灾的位置对车厢内的温度、能见度和烟气流动都有影响。火源附近的温度在发生火灾时会迅速升高,所达到的最高温度也最大,火源顶部最高温度达到了150℃。能见度下降最快,最低降至1.5m,烟气浓度也最高。建议当公交车内发生火灾后应保证车窗关闭,人员立即远离火源并从车门逃生,待灭火结束后立即开启全部车窗。
[Abstract]:In recent years, the frequent fire incidents of buses in China have caused great harm to social stability and safety. Therefore, it is necessary to study the fire extinguishing of the bus. The experiment and simulation of the fire extinguishing with water mist are carried out in this paper. The weighted evaluation model of the fire and smoke toxicity after the fire is analyzed theoretically. The fire extinguishing experiment was carried out in a real bus. The water mist fire extinguishing system was installed in the car, and the oil pan gasoline fire was used in the fire. Four fire extinguishing experiments were carried out. The fire extinguishing performance of the water mist fire extinguishing system in the bus, the temperature distribution in the car after the fire and the fire extinguishing were studied. This paper simulates and studies the rule of smoke flow after the fire and fire extinguishing in the car, and analyzes the different opening positions of the window, the opening time of the window and the location of the fire source respectively to the temperature inside the car. The effects of visibility and smoke flow. By analyzing the characteristics of bus fires, the hazards to human health caused by fire and smoke after extinguishing are analyzed. Two weighted evaluation models of smoke toxicity, FED model and N-Gas model, were analyzed and compared. The shortest fire extinguishing time was 4 s and the longest was 9 s. The highest temperature appeared above the fire source and the highest temperature was 380 鈩，

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