Abstract: In order to study the effects of different smoke exhaust modes on the evacuation in a fire scenario, a double-deck island subway station was taken as example, the fire model was established by FDS, and the distribution of fire smoke temperature, CO concentration and visibility of subway stations under 4 exhaust modes were analyzed. Within the specified evacuation time of 360 s, at the height of the human eye as 1.6 m, the evacuation route under the natural smoke exhaust mode has the area which temperature is greater than 60 ℃, CO volume fraction is greater than (250×)10-6, and visibility is less than 10 m. Under the evacuation mode of the smoke exhaust, there is an area with visibility less than 10 m in the evacuation route. The mode of smoke exhaust in the public area of the station, and mixed smoke exhaust of station public area and station tunnel, the fire smoke temperature, CO concentration and visibility in the evacuation route area are lower than the evacuation index.

Key words: ventilation and exhaust, numerical simulation, temperature, visibility, CO concentration