建筑火灾烟气中CO迁移规律的FDS模拟

以T型"侧间-走廊"典型建筑火灾为模拟对象,分析烟气在走廊中的水平和垂直流动特征,并对火源房门高低、走廊端头启闭和多房门启闭等场景使用火灾模拟软件(FDS)进行了模拟和远距离房间CO浓度的迁移规律的分析。结果表明:烟气从火源房间经拱腹溢出在走廊中形成受限空间的顶棚射流;门檐高度决定了CO能够在走廊中的迁移量;烟气在走廊远距离封闭端头形成上部的热烟气层,中部回流层和下层的补气层;其中中部烟气回流层的高低、流速和CO浓度是影响临近非火源房间CO浓度的重要因素。走廊启闭和多房门火灾场景的模拟结果也进一步证明了CO的迁移规律。

Numerical Simulation on the Spreading Rule of CO in Building Fire by FDS

The structure of fire scenarios for simulation was a T-style Room-Corridor in this paper.The smoke flow characteristics of horizontal and vertical levels in corridor were analyzed.Some scenarios such as different soffit levels of fire room door,the vent condition of the two extremities in corridor and two distant locations,were evaluated by FDS.The CO concentration at a distant location was studied and the species transportation pattern was presented.The simulation results indicate that the smoke flow around the soffit of the fire room and impacts the opposite corridor wall.Then a limited jet flow on ceiling is formed.The quantity of CO transportation in corridor is decided by the soffit level.The upper hot-smoke layer,middle circumfluence layer and lower supply layer are formed near the end of corridor.The level of middle circumfluence layer,smoke flow rate and CO concentration are the main influence factor for CO concentration in distant locations.Those rulers of CO transportation are validated by the other two fire scenarios simulation.