室外风对火灾烟气蔓延影响的数值模拟研究

Numerical Simulation of Outdoor Wind Influence on Smoke Movement

通过数值模拟分析室外风作用下烟气蔓延特征,以期为高层建筑灭火救援提供理论依据。利用FDS软件建立高层建筑起火层全尺寸模型,分析室外风风速对火灾烟气蔓延规律的影响。模拟结果表明:风速为6.5 m·s^(-1)场景热释放速率峰值约为无风条件下的1.6倍,当室外风风速大于10 m·s^(-1)时,热释放速率随风速增大反而减小;室外风进入起火房间后,起火楼层各区域温度、能见度、烟气层高度、流体速度均与无风条件下存在较大差异。针对此情况,需采取优化系统性能、充分侦察评估、精准应用设施、灵活选用装备等相应对策确保灭火救援作战安全。

This paper analyzes the characteristics of smoke movement under the influence of outdoor wind by Numeri⁃cal Simulation in order to provide theoretical basis for firefighting and rescue of high-rise buildings.Full-scale FDS model of the floor on fire with different velocity of outdoor wind is built to simulate and analyze smoke movement properties.The results show that:the peak heat release rate of the scenario with a wind speed of 6.5 m·s^(-1) is about 1.6 times that of the windless condition.When the outdoor wind speed is greater than 10 m·s^(-1),the heat release rate decreases with the increase of the wind speed.After the outdoor wind enters the room on fire,the temperature,vis⁃ibility,smoke layer height,and fluid velocity of various areas of the fire floor are significantly different from the windless condition.In this situation,it is necessary to take such countermeasures as optimizing the smoke control system performance,conducting thorough investigation and assessment,employing facilities with precision,and selecting equipment flexibly to ensure the safety of firefighting and rescue operations.