排烟口朝向与挡烟垂壁对地铁站台排烟效果的影响

Influence of smoke vent orientation and draft curtain on smoke exhaust effect of subway platform

为提高地铁站台的排烟效果,采用数值模拟方法,对地铁站不同排烟口朝向的机械排烟系统排烟效果进行分析,并进一步对比挡烟垂壁高度对排烟效果影响。研究结果表明:排烟口朝向不是影响烟气控制效果的主要因素,顶面排烟的排烟效果最佳,其总排热量是底面排烟的1.32倍,总排烟量是底面排烟的1.19倍;并通过分析3种排烟系统吸入烟气的方式和温度解释排烟效果产生差异的原因;增设挡烟垂壁可起到良好的控烟效果,当挡烟垂壁下沿高度分别降低至3.5,3.0,2.5 m时,顶面排烟,侧面排烟和底面排烟能够将烟气控制在起火防烟分区;挡烟垂壁与机械排烟系统具有协同作用,设置挡烟垂壁可以有效改善排烟效果,因此建议采用排烟管道顶面开口的排烟方式,并可通过设置一定高度的挡烟垂壁提高现有排烟系统的排烟效果。研究结果可为地铁站台排烟系统设计提供参考与借鉴。

In order to improve the smoke exhaust effect of subway platform,the smoke exhaust effect of the mechanical exhaust system in subway station with different smoke vent orientations was analyzed through numerical simulation,and the influence of the height of draft curtain on the smoke exhaust effect was further studied.The results show that the orientation of smoke vent is not the main factor affecting the smoke control effect,the exhaust effect of top surface smoke exhaust is the best,its total exhaust heat is 1.32 times that of the bottom smoke exhaust,and the total smoke exhaust volume is 1.19 times that of the bottom smoke exhaust.The reasons for the difference in smoke exhaust effect are explained by analyzing the inhalation methods and temperature of the three smoke exhaust systems.Adding the draft curtain can play a good smoke control effect,and when the lower height of the draft curtain is reduced to 3.5 m,3.0 m and 2.5 m respectively,the smoke can be controlled in the fire smoke control zone by top surface exhaust,lateral exhaust and bottom exhaust.The draft curtain has a synergistic effect with the mechanical smoke exhaust system,and the smoke exhaust effect can be effectively improved by setting draft curtain.Therefore,it is recommended to adopt the smoke exhaust mode with top surface vent of the smoke exhaust pipe,and the smoke exhaust effect of the existing smoke exhaust system can be improved by setting a certain height of the draft curtain.The research results can provide reference for the design of smoke exhaust system of subway platform.