Control On The Subway Fire Of Mechanical Exhaust And Water Mist Coupling

In recent years, the underground fire at home and abroad and frequent accidents, causing a serious threat to the safety of life and property. Effective control of the spread of fire and smoke of the subway is particularly important to protect the safety of personnel evacuation. In this paper length×width×height100m×80m×5m subway platform Numerical simulation of water mist fire extinguishing simulation research has guiding significance for the promotion of water mist fire suppression technology and corresponding national standards launched.First simulation study on the subway platform2.5MW fire fuel heat release rate, site export1.5m at the height of the comparative analysis of the volume fraction of CO, respectively discuss water mist nozzle spacing2m and3m two conditions, fine waterextinguishing effect of fog on the subway platform.The research results show that the spacing of2m when water mist nozzles, water mist flow rate of10m/s to achieve extinguishing effect; water mist nozzle spacing of3m, water mist rate increased from10m/s to15m/s toachieve extinguishing effect. Water mist nozzle spacing the2m conditions change the location of the source of fire within the site, simulation analysis of water mist injection velocity on the subway platform fire extinguishing effect, draw water mist nozzle spacing of2m conditions, the fire source is located in the nozzle is below, the water mist nozzle flow rate of10m/s to reach the extinguishing effect; fire source is located in the nozzle just below the water mist nozzle flow rate increased from10m/s to15m/s to reach the extinguishing effect.Further discussion of water mist nozzle spacing2m of water mist fire source is located just below the two kinds of water mist flow rate of10m/s and when the fire source is located in a fine mist of non-just below the water mist flow rate of15m/sconditions, set the start time of mechanical exhaust were60s,120s, and150s three cases, changes in the power of the source of fire, the temperature at1m above the fire source and site export1.5m at the height of the volume fraction of CO contrast, analysis of different timeto start mechanical exhaust water mist fire extinguishing, discuss mechanical exhaust and water mist to the subway platform fire control. The results show that the mechanical exhaust and water mist extinguishing start condition shortest time and the best results.Finally, the measured piston wind fire occurred120s introduced into the subway platform fire simulation, First discuss the piston wind development on the subway platform fire source; piston wind and then discuss the role of water mist fire extinguishing; final discussion of the piston windwith mechanical exhaust under the joint action, the interaction of water mist with the subway fire. Unstable simulation results show that:the piston wind made the fire source fire heat release rate, the proliferation of toxic fumes fast, you need to take the necessary measures to control smoke diffusion; water mist fire heat release rate caused by the sudden increase to1.5MW; piston wind disrupt water mist spray range makes the the evacuation passage of CO concentration increased threat of evacuation; open at the same time under the influence of wind piston mechanical smoke and water mist fire play a very good subway platform control role, making the spread of toxic smoke has also been effectively curbed.