地铁站台煤油火灾烟气蔓延的数值模拟

Numerical Simulation of Kerosene Fire/Smoke Spread over Subway Station Platform

以沈阳地下铁路工程为例.利用计算流体力学的SIMPLE算法,在5种防排烟方式下,对地铁站台煤油火灾烟气的蔓延情况进行数值模拟.选取距地铁站台地面2m平面上,两楼梯口中心点作为测点,得到了不同防排烟情况下测点温度及CO_2摩尔分数的实时曲线,及地铁火场温度和CO_2浓度场云图,分析不同的防排烟方式对地铁站台煤油火灾烟气蔓延情况的影响.模拟结果表明,当仅使用机械排烟时,排烟口位置不同,排烟效果相差不大.加压送风系统与机械排烟同时使用,能有效遏制烟气蔓延,并出现周期性衰减的情况;远离火源的楼梯口可作为更加安全的疏散通道.

Based on the Shenyang subway project, a numerical simulation of kerosene fire/smoke spread over the subway station platform was performed by the software CFD and SIMPLE algorithm for fluid mechanics, including 5 different types of smoke exhaust systems. The centers of two stairway openings on the plane 2 m above platform floor were taken as test points where the time-dependent relationship between temperature and CO2 mole fraction and the cloud charts of fire scene temperature and CO2 concentration fields were obtained to analyze how the different ways to exhaust smoke affect the spread of fire/smoke at subway station platform. The results showed that when the mechanical smoke exhauster is used solely, the position difference of exhauster outlets affects unobviously the fire/smoke control effectiveness. But, the exhauster in combination with forced draft system can inhibit more efficiently the spread of fire/smoke though periodical attenuation is found during the inhibition. The stairway farther from the fire center is proved the safer exit for human evacuation.