Research on Smoke Flow Characteristic in Subway Tunnel Fire

摘要

With the rapid development of construction and management of subway in China, fire safety has drawn more attention in subway tunnel. It is necessary to study and simulate the situations like the power and position of fire, smoke diffusion, temperature distributing and fan operation, and the result can help analyzing fire state at the pot, controlling the and and evacuating people. A three-dimensional mathematical model of the smoke movement in tunnel fires was established. Finite volume method was used to discretize the governing equations and the SIMPLE algorithm was employed to solve the governing equations. A scaling model (1:8) of the subway tunnel was buiR up based on similarity theory. The steady and unsteady fire situations of experiment have been done on the scaling benchmark model. Further computer simulation will also be applied on it and compared with the result in experiment to validate the usefulness of simulation. In experiment we considered both different positions of fire on the train and different starting times of exhaust fan in the tunnel. The disciplines of smoke temperature, smoke diffusion and wind velocity have then been compared with the situation changes. The study brings forward a conclusion which is useful to analyze people evacuating and fire controlling in emergent of tunnel fire in Beijing subway system.