Research On Highway Tunnel Fire Simulation And Fire Ventilation

With the quantity and the length of tunnel increasing and the traffic density growing, therate and expand of fire accident hazard in highway tunnel is growing. A large amount of datashows that fires happened in highway tunnel have caused enormous social impact andeconomic losses. Main factors causing harm is toxic smoke generated with high temperatureflow, and the reasonable ventilation project can control the smoke effective flow temperatureand its spread speed and direction. Study on the tunnel fire ventilation control, which hasimportant significance for fire damage of rescue and prevent high temperature tunnelstructure.In this paper, using the computer fluid dynamics (CFD) numerical simulation technology,and using pyrosim software for tunnel fire simulation, discusses the model built tunnel smokespread rule under different wind speed. Calculated by simulating fire size is20MW, under thenatural ventilation condition how the spread of smoke flow and temperature conditions move.Then in different mechanical ventilation velocity transient simulation, calculated consideringthe ventilation changes in wind speed, gets smoke diffusion range and highest temperaturechange rule, at the same time draw the critical wind speed of fire whose scale is20MW, andoffer advice to the Tunnel disaster relief. At last based on the characteristics of tunnel fireventilation control of time lag, a fire in the middle of tunnel was also simulated in differentreaction time to find the influence of reaction time, according to the fire regularity of escapeand spread of smoke temperature, Identify the most conducive to staff can effectively controlthe smoke flow and escape the reaction time and the mechanical ventilation and wind speed.Finally, according to the characteristics of tunnel fire ventilation control time lag and thefire evacuation of smoke temperature spread rules, find out effectively control the smoke flowand the most conducive to the workers fled the reaction time and the velocity of mechanicalventilation.