倾斜导烟板对隧道机械排烟效果影响研究

摘 要：排烟口风速随着负压差增大而增大，而增大排烟口负压容易出现吸穿效应，同时由于烟气沿顶棚纵向扩散时存在水平惯性力，往往还未进入排烟口就流向其后方，使控烟效果变差。针对上述问题，在排烟口下方设计了一种倾斜导烟板（ISD）来优化排烟口处流场，增大排烟口处的负压差，抵挡排烟口下方烟气的水平惯性力并抑制吸穿效应，提高排烟效率。应用FDS模拟验证ISD对排烟效果的影响，结果表明，ISD装置能明显提高排烟口的排烟能力，当倾斜挡烟板垂直高度为600 mm时，与普通排烟口相比，流向下游的热量流量减少99.8%，排烟口下方负压增大3倍，并且对抑制吸穿现象效果明显，机械排烟效率得到提高。

Influence of inclined smoke deflector on mechanical smoke exhaust effect of tunnel

Abstract: The wind speed at the exhaust outlet increases with the increase of negative pressure difference, increasing the negative pressure of the smoke exhaust outlet is prone to suction through effect. At the same time, due to the horizontal inertial force when the smoke diffuses longitudinally along the ceiling, it often flows to the rear before entering the smoke exhaust outlet, which makes the smoke control effect worse. To solve the above problems, an inclined smoke inflector (ISD) is designed under the smoke outlet to optimize the flow field at the smoke outlet, increase the negative pressure difference at the smoke outlet, resist the horizontal inertia force of the smoke below the smoke outlet, inhibit the penetration effect and improve the smoke exhaust efficiency. FDS simulation is used to verify the influence of inclined smoke deflector on smoke exhaust effect. The results show that ISD device can significantly improve the smoke exhaust capacity of smoke exhaust outlet. When the vertical height of inclined smoke deflector is 600 mm, compared with ordinary smoke exhaust outlet, the heat flow to downstream is reduced by 99.8%, and the negative pressure under smoke exhaust outlet is increased by 3 times. Moreover, it has obvious effect on inhibiting the phenomenon of suction penetration, and the smoke exhaust effect is improved.