Numerical Simulation of Shock Wave Propagation Law of Coal Dust Explosion in Complex Pipeline Networks

In order to study the shock wave propagation law of coal dust explosion in complex structures, the diagonal pipe network model was established by using computational fluid dynamics software, and the numerical simulation of the coal dust explosion in the diagonal branch was carried out. The change law of the shock wave and its attenuation at the corner were analyzed. The results show that the pressure change process of coal dust explosion can be divided into three stages, namely, the stage where the pressure value at the ignition point is relatively high, the stage where the pressure value on both sides of the ignition source is maximum, and the stage where the pressure value at the shock wavefront is relatively maximum; the overpressure of the shock wave decays at the bifurcation point, and the larger the bifurcation angle, the greater the pressure attenuation amplitude. For the same bifurcation angle, the greater the initial pressure at the monitoring point, the greater its attenuation amplitude. Multiple regression fitting on the shock wave pressure values was performed before and after turning, and the function relationship between the shock wave pressure attenuation coefficient and the initial pressure, as well as different turning angles, was obtained. The fitting results can be used as a formula for calculating the ventilation network during the disaster process, which has theoretical significance for evaluating the consequences of coal dust explosion accidents.