Abstract: In order to study the smoke control effect of point smoke exhaust system in the asymmetric V-shaped tunnel, the scale model experiments were carried out. Taking the design fire of 20 MW as an example, based on the study of the reasonable smoke exhaust volume rate in normal tunnel, the influences of different slope combinations and different opening modes of smoke exhaust vent on the smoke control effect were studied for the V-shaped tunnel when the fire source was located at the slope changing point. The results show that smoke exhaust of 140 m3/s can effectively control the smoke for the design fire of 20 MW. For the V-shaped tunnel, when 3 smoke vents are opened symmetrically on both sides of the fire source, the smoke diffusion on the side with a large slope cannot be effectively controlled. In this case, the number of smoke exhaust vents on the side with a large slope can be appropriately increased. When the slope difference between the two sides of V-shaped asymmetrical tunnel is too large, especially when the slope of the large slope side is too large, it is difficult to control the smoke effectively.

Key words: V-shaped tunnel, fire, small-scale experiment, point smoke exhaust system, smoke control