Study On The Law Of Smoke Flow In Highway Tunnel Fire

Due to the space structure of highway tunnel is relatively closed and narrow,when the fire occurs in the tunnel,the rapid spread of smoke,resulting in personnel escape and fire rescue is very difficult.the relatively closed and narrow space structure,once the fire occurs,smoke spread rapidly.The tunnel space fire safety platform supported by Beijing scientific research funds based in Xiamen,a highway tunnel as the engineering background,the tunnel fire smoke flow and evacuation scheme was studied,the specific work as follows:(1)By similarity principle of tunnel fire and the principle of model test,the similarity relation between model and prototype corresponding physical quantity is given.In a fire section of actual highway tunnel as the prototype,according to the similarity theory,with the ratio of 1/9 to build a platform size shrinkage test tunnel,and the introduction of networking detection equipment for direct detection of fire smoke concentration.(2)According to the orthogonal design theory of orthogonal test scheme,orthogonal test of the fire in the tunnel model,completed the acquisition and consolidation of data,in the study of the mechanical exhaust under different fire heat release rate,affect the position of the gas and water distribution of fire smoke exhaust velocity and fire,and use range analysis,analysis of the main effect of three factors.(3)Using FDS software,a numerical model is built according to the test tunnel model.The numerical simulation analysis of nine test cases is carried out.The simulation results are compared with the experimental data,and the error reasons are analyzed.In addition,through the simulation results,the law of smoke diffusion,the horizontal and vertical distribution of CO and the distribution law of smoke temperature are emphatically analyzed.(4)The establishment of the original size of the tunnel numerical model,simulation of heat release rate of 20MW fire,analysis of flue gas concentration distribution under different exhaust velocity,and determine the conditions according to the evacuation,in different locations of the tunnel escape plan staff to study the effect of different exhaust velocity,and provides a basis for the fire escape.