Abstract: 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.

Key words: Key words: tunnel fire, smoke vent, smoke deflector, smoke control, numerical simulation