多火源地铁站的火灾模拟及烟气特性分析

Fire Simulation and Smoke Characteristics Analysis of Multi-Fire Source Subway Station

为探究岛式地铁站火灾环境下的烟气蔓延规律,本文以某岛式地铁站为研究对象,用Pyrosim建立地铁火灾模型,观测多火源场景下地铁火灾的发展过程,研究其楼梯和出口附近的烟气能见度、烟气温度、烟气高度和温度的变化规律。研究发现:火源分布位置均匀的情况下,烟气温度的扩散具有对称性;地铁火灾燃烧初期,靠近外部火源的楼梯附近的烟气能见度会在下降的过程出现回升的现象;在火灾达到充分发展阶段时,车站中部的一氧化碳浓度回落的幅度更加明显;110 s后,烟气高度开始波动,逐渐趋于稳定,地铁火灾发展到燃烧增长阶段,烟气温度的上升开始到威胁人身安全。

In order to explore the law of smoke spread in the fire environment of an island-style subway sta-tion, this article takes an island-style subway station as the research object, uses Pyrosim to build a subway fire model, observes the development process of subway fires in a multi-fire source scenario, and studies its stairs and exits. The nearby flue gas visibility, flue gas temperature, flue gas height and temperature changes. The study found that: when the fire source is evenly distributed, the diffusion of the flue gas temperature is symmetrical. In the early stage of a subway fire, the visibility of smoke near the stairs close to the external fire source will rise during the downward process. When the fire reached its full development stage, the concentration of carbon monoxide in the middle of the station dropped more significantly. After 110 s, the flue gas height began to fluctuate and gradually stabilized. The subway fire developed to the combustion growth stage, and the rise of the flue gas temperature began to threaten personal safety.