Study On The Spread Regularity And Control Of Fire Smoke In Large Scale Interchange Tunnel

In recent years with the development of our country highway road network, road tunnel because of its neat highway linear, decrease the distance of driving, etc, are increasingly applied to the construction of highway network. With the development of tunnel construction technology, large-scale interchanges tunnel gradually appear in highway tunnel. Because interchanges tunnel in structure form the convergence of the tunnel and bifurcation, exist in the tunnel fire, especially in the bifurcation in a fire, the fire smoke migration rule and control of the fire smoke is different from the traditional single tube tunnel. In this paper, which is based on Shenzhen transit expressway connecting line project, using numerical simulation software Fluent, the large-scale interchanges in case a fire occurs in a tunnel ventilation resistance and the flue gas migration rule and control are analyzed.Second, because the tunnel ventilation resistance is the important factors that affect the whole tunnel ventilation performance and effect, therefore, comprehensive and systematic analysis and study on the influence of the tunnel ventilation resistance is very important. Grew up in this paper using Fluent software, the interchanges tunnel ventilation svstem all details of the three-dimensional numerical simulation analysis and research. Main content includes:different section straight line tunnel of frictional resistance and the frictional resistance of the tunnel cross section curve, local resistance when opening the dealership horizontal channel, bifurcation tunnel of local resistance.Then, based on the Shenzhen east channel connecting engineering has the characteristics of the convergence of the tunnel and the bifurcation tunnel, when the fire broke out in the flue gas field and velocity field is different from the traditional single tube tunnel, therefore using Fluent software, the Shenzhen east channel connecting engineering tunnel under different fire scenarios of flue gas field, temperature field and velocity field were analyzed and studied. By using 20 MW fire source, and analyzes the different line segment tunnel section, bifurcation confluence and distributary channel of critical wind speed and flue gas field, temperature field and velocity field, to grow up interchanges tunnel ventilation system designed to provide specific parameters.Finally, the large-scale interchanges the fork of the tunnel was simplified reasonably, ignores the curve of the tunnel, the movement of local analysis method, 20 MW and 50 MW,5 MW and fire research analyzed the bifurcation angles, bifurcation cross-sectional area ratio and bifurcation point of upstream and downstream of the arch length on the influence of fire smoke control.