Study On Sichuan Ming Yueshan Tunnel Fire Smoke Spread Characteristics Of The Local Numerical Simulation

Due to the special structure of the tunnel, especially long highway tunnel in case of fire, if not timely discovery and extinguished it, the fire will spread quickly.In this way, the other vehicles could not be evacuated as soon as possible, which causes heavy casualties and property losses. Many experts at home and abroad just have done a lot of research on the smoke temperature distribution and control scheme for tunnel fire, which use the longitudinal ventilation. But the role of the flue tunnel fire, such as smoke exhaust from different positions, and their influence of the smoke distribution and stratification. Based on " Sichuan Dianlin highway Mingyueshan tunnel ventilation and fire Rescue Research " project. We have done a lot of numerical simulation analysis. Finally, we summarized several conclusions as follows:(1) Wind speed of the exhaust does not affect the tunnel upstream control。When the fire far away from the smoke exhaust, the wind speed of the smoke exhaust has little effect on the downstream distribution of smoke (If the smoke float from the fire source about 400m, it will be completely diffusion).When the smoke exhaust near the fire source, the upward pressure which is generated by exhaust can make the smoke distribute clearly between the smoke exhaust and the fire source. So within 2m above the ground, the smoke concentration is lower; in this way the people and the vehicles would evacuate more easier. But in order to ensure that the smoke will not be disturbed in the smoke exhaust downstream, we must make import section flow Q1 and Q2 flow of smoke exhaust's ratio is greater than 1:1.(2) Obtained in case of traffic jam, the size of the critical wind speed with the different fire in the tunnel, and through the different traffic jam length (250m and lkm) simulation studies. Under the circumstance that the critical wind speed with fire have noting to do with length of the traffic jam.(3) Using numerical simulation to 4 different shapes and sizes of smoke exhaust section,to find the best one on exhaust Smoke effects.Through this article study, combining Mingyueshan tunnel operation equipment arrangement to provides the basis for tunnel fire rescue plan.