阻塞效应下隧道火灾烟气蔓延及温度分布特性研究

发布时间：2018-05-01 11:34

本文选题：隧道火灾 + FDS　；参考：《西安建筑科技大学》2017年硕士论文

【摘要】：随着中国城市化进程地加快,城市人口越来越多,城市交通系统承受的压力也越来越高。为了缓解交通压力,减轻交通拥堵,我国许多城市开始进行地铁建设。由于地铁结构的特殊性,在地铁区间隧道一旦发生火灾,极易造成群死群伤事故以及重大经济损失。目前,关于地铁隧道火灾的研究多是针对无坡隧道,不考虑列车阻塞的影响。而实际情况中,坡度以及阻塞效应不可忽略。基于此情况,确定本文的研究内容。本文以某一实际区间隧道内列车起火为原型(阻塞比为50%)建立了仿真模型,利用FDS模拟软件分别模拟了列车中部起火、尾部起火时列车停止在水平或不同坡度(分别为1%、2%、3%)的隧道内的动态烟气流场和温度场。模拟结果与缩尺模型试验结果相对比,验证了模型的正确性;在自然通风和纵向通风条件下,分别分析了坡度对隧道火灾烟气蔓延特性以及烟气沿隧道顶棚温度分布、隧顶最高温度及其出现位置的影响;接着分析了列车中部着火与列车左端着火时,隧道内烟气蔓延的不同规律,研究了列车左侧或右侧2m处,不同高度上的温度变化和CO浓度变化规律;分析了列车中部着火时,火源热释放速率对顶棚温度分布的影响;最后研究不同纵向通风速度(分别为0 m/s、1 m/s、2 m/s)对隧道内烟气蔓延特性及顶棚温度分布影响。结果发现:纵向通风速度对顶棚下的温度分布会产生明显的影响;火源位于列车左端时,由于火源左侧无阻塞物的影响,烟气有部分向下沉降;列车着火位置不同,坡度对顶棚下的最高温度及其出现位置的影响亦不同。
[Abstract]:With the acceleration of urbanization in China, the urban population is increasing, and the pressure on the urban transportation system is increasing. In order to relieve traffic pressure and traffic congestion, many cities in China began subway construction. Due to the particularity of subway structure, once a fire occurs in the subway tunnel, it is easy to cause mass death and mass injury, as well as great economic losses. At present, most of the researches on subway tunnel fire are aimed at slope-free tunnel and do not consider the influence of train congestion. In practice, the slope and the blocking effect can not be ignored. Based on this situation, the research content of this paper is determined. In this paper, a simulation model of train fire in a tunnel with a blocking ratio of 50 is established, and the fire in the middle of the train is simulated by FDS software. At the end of the fire, the train stops the dynamic flue gas flow field and temperature field in the tunnel with horizontal or different slopes (1 / 2 / 3 respectively). The simulation results are compared with the results of scale model test, and the correctness of the model is verified. Under the condition of natural ventilation and longitudinal ventilation, the characteristics of slope to the smoke spread of tunnel fire and the temperature distribution of flue gas along the tunnel roof are analyzed, respectively. The influence of the maximum temperature on the top of the tunnel and its occurrence position is analyzed, and then the different rules of smoke spread in the tunnel are analyzed when the train is on fire in the middle and the left end of the train, and the 2m on the left or right side of the train is studied. The influence of the heat release rate of fire source on the temperature distribution of the roof is analyzed when the train is on fire. Finally, the effects of different longitudinal ventilation velocities (0 m / s ~ (-1) m / s ~ (-1) / s ~ (2) m / s) on the smoke spread and temperature distribution in the tunnel were studied. The results show that the longitudinal ventilation velocity has obvious influence on the temperature distribution under the roof, and when the fire source is located at the left end of the train, the smoke has a partial downward settlement due to the influence of non-blocking material on the left side of the fire source, and the fire location of the train is different. The effect of slope on the maximum temperature and its appearance under the roof is also different.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U458

【参考文献】