自然通风下横向走道防排烟方式和排烟口位置对烟气状态的影响模拟

Effect Simulation of Smoke-exhausting Way and Smoke-exhausting Position on Smoke Diffusion in Walkway under Natural Ventilation

通过建立高层建筑内烟气流动的数学模型,采用k-ε双方程三维紊流模型对高层建筑火灾时横向走道内不同防排烟方式和不同位置的排烟口对烟气状态的影响进行数值模拟;通过分析比较,得出对于火灾初期挡烟垂壁对延缓烟气扩散的效果明显,可以通过设置合理的挡烟垂壁高度和数量来延长疏散时间;笔者认为,重要场所应用机械排烟时,排烟口应避免设在前室附近,应将排烟口设置在以挡烟垂壁为防烟分区的中间部位;在保持总排烟量不变和不过分增加经济投入时应增设排烟口的数量以达到最佳排烟效果。

A mathematic model of smoke flow in high-rise building is established and a k -ε three-dimensional turbulence model with two equations are used to simulate the effect of smoke-exhausting way and smoke-exhausting position on the smoke distribution in the walkway under the natural ventilation. By comparison and analysis, it is concluded that the hang wall is obviously effective to prevent smoke diffusion in the early fire, and the evacuation time could be prolonged by designing reasonable height and numbers of the hang wall. For some important place where mechnical exhaust way is adopted, the exhaust outlets shouldn＇t be fixed around the atria, but in the center of the hang wall. The number of exhaust outlets should be added under the conditions of keeping the quantity of exhausted smoke unchangeable and not increasing economic input so as to get the best smoke-exhausting effect.