Simulation analysis of fire smoke in long mountain tunnels of underground railways

By establishing a large-scale unsteady model and using Fluent software, the smoke flow pattern of train fire in a long mountain tunnel is simulated. The influence of piston wind generated from the train running on the smoke flow of the burning train is analysed, and the different jet fan setting schemes are compared. The results show that in the ventilation and smoke exhaust scheme design of the long mountain tunnel, not only the smoke exhaust wind speed and critical wind speed from 2 to 11 m/s should be met, but also the wind speed requirement of restraining smoke reflux should be considered in order to better meet the safety requirements of personnel evacuation in case of fire. It is suggested that the number of jet fans can be increased, and 8 groups of jet fans should be installed at each end of each line.