Diffusion Simulation And Emergency Study Beijing Subway Station Gas Leak

Subway, as a convenient means of transport,plays an important role in daily life.Without property emergency plan, the emergence circumstance will result in immeasurablecasualties and property losses.This paper discuss gas diffusion problem of Beijing subway station emergencies. Themodel was determinedaccording to the basic equations of fluid and gas diffusion equationsmodel problem,selecting FLUENT14.5software for geometric modeling, meshing,boundary conditions, etc. The paper discuss gas diffusion regular pattern in the gas bombsmode of the subway station. As can be seen from the poison gas leakage and diffusionconcentration distribution, gas distribution disorders early, then gradually both sides of thespread of various air vents below the competition unfold, and gas spread upward andstretched wider distribution of high concentration area, located in the passenger platformlayer will be exposed to high concentrations of large chlorine environment, when800s,spread to the hall, but the concentration is gradually decreased.The effect of different settings (release position and air exhaust mode) on the poisongas diffusion is analyzed. Results showed that it is much more dangerous when poison gasreleasing from station layer and the fan should not be opened until the gar spread to stationlayer. The semi open mode is more efficient than whole open air exhaust mode. The“ground” air exhaust mode could reach a better air exhaust efficient due to the heavierdensity of chlorine.The lethal zone, serious injury zone, minor wound zone and mild symptoms zonewere divided according to probability function. And the evacuation plans of different zoneswere put forward. At the same time, the contingency plan of Beijing railway station weresupplemented and improved based on platform layer, station layer and carriage.