Study On The Smoke Blockage By Air Curtains Installed At The Front Opening Of Stairs In Subway Station

The urbanization of our country brings great pressure to traffic. As a new kind of transport, subway can effectively improve our traffic condition. Subway was widely built by many cities. But there are many safety problems in subway, subway is a underground transportation, the roads are complex and intensive. Different from ground passenger flow volume in subway is great, coupled with sufficient of evacuation exit, it will more likely happen serious accident, which will cause the death and hurts of many people. The rational design of exhaust system and evacuation in the subway is a key way to reduce the loss cause by fire accident.So, the research of fire smoke separation technology is urgent. To provide the theoretical support to subway fire safety design, it is necessary to study the effect of different types of fire smoke separation technology.Air curtain was widely used in fire smoke separation technology, the effectiveness of air curtain was mainly up to flow speed and location. In this paper, we study the effectiveness of air curtain to fire smoke separation in different flow speed and angle through theoretical analysis, numerical simulation and full size experiment.First, we start our study based on theoretical analysis. We promote our study through full size computer simulation, At last, we conducted a full-size experimental study conducted full-scale experimental study to the Shuiyang station.The chief goal of our project is study the effectiveness of air curtain in smoke separation and it’s relationship with the fire power and the thickness of smoke layer. Considering the influence of the spray system and mechanical smoke extraction to glue gas flow, determine the best flow speed and direction of air curtain and provide the support to the use of air curtain in subway.Our study was focus on three aspects, first we study the requirements of the design of flow speed and direction in use of open stairs. Second we study the influence of smoke extraction and air make-up in platform to the air curtain with consider of smoke exhaust rate, smoke hanging wall of air curtain. Thirdly we study the effect of air curtain on low temperature flue gas mixing when reduce smoke buoyancy by water spray.We analyzed air curtain smoke flow field with numerical simulation based on FDS. Then compared with theoretical results,determine the design requirements of air curtain smoke At last, we obtain the experimental data under typical fire power by conducted a full-size experimental study conducted full-scale experimental study to. Test the effectiveness of the air curtain smoke and numerical simulation.We found that the most effectiveness of air curtain occur when the flow speed range from 5 m/s to 7 m/s, dip angle range from 15°to 30°through the numerical simulation and full-scale experimental. We found that the air curtain can be a effective way in the early of fire and it will not affect the exhaust system. So the air curtain is a useful technology in preventing the flow of smoke, it should be widely application in the subway.