喷淋和排烟系统对地铁站台火灾的影响研究

Study on the Influence of Water Sprinkler and Smoke Exhaust System on Subway Platform Fire

采用火灾动力学软件FDS对沈阳某二层岛式地铁站站台火灾场景进行模拟,分析站台不同位置发生火灾以及由喷淋和排烟系统组合成不同工况时,站台内不同高度处温度、CO浓度和热辐射的变化,为地铁站防火措施和人员疏散方案提供参考。结果表明:不同位置发生火灾时,站台内的火灾烟气运动规律不同,端部火灾的影响范围较中部火灾的小;站台顶棚处的温度比2 m高度处的高,CO浓度比2 m高度处的大;距火源5 m内,顶棚的热通量比2 m高度处的低,但距火源5 m外,顶棚的热通量比2 m高度处的高。开启喷淋或排烟系统都可降低站台温度,喷淋系统主要降低火源周围温度,排烟系统可有效降低CO浓度并改善能见度;喷淋和排烟系统还可以降低火灾发生时站台顶棚处的热通量。

The fire dynamic software(FDS)was used to simulate the scene of a two-floor subway when fire accident happened on the platform,in which the changes of temperature,CO concentration and heat flux radiation at different heights of the platform were analyzed when the fire occurred at different positions of the platform and under different working conditions combined with water spray and smoke exhaust system.The results show when fire happens in different positions,the smoke moves differently in different positions and the influence of the side fire is smaller than the middle fire;the temperature of 4.7 m-high is higher than that of 2 m-high;CO concentration is larger than that of 2 m-high;heat flux radiation is lower than that of 2 m-high within 5 meters from fire source,but higher than that of 2 m-high when 5 meters away from fire source.The opening of sprinkler and smoke exhaust can both reduce the temperature when the fire accident occurs,in which the sprinkler reduces the temperature around the burner mainly and the smoke exhaust system can effectively reduce the CO concentration and improve the visibility,and both of them can reduce the heat flux when fire accident happens on the platform.