Propagation and attenuation characteristics of shock waves in a gas-coal dust explosion in a diagonal pipeline network

In order to obtain the propagation and attenuation characteristics of a shock wave gas-coal dust explosion, a diagonal pipeline network was built to carry out a gas-coal dust explosion experiment. Methane with a volume fraction of 9.5% was mixed with 20 g of coal dust with a particle size of 50 mu m. The shock wave attenuation characteristics in the diagonal pipeline network were characterized by the overpressure attenuation coefficient. The results showed that when the shock wave propagated in the diagonal pipeline network, it was offset and superposed multiple times. The overpressure attenuation in diagonal pipes was greater than that in the other pipeline branches. Secondary explosions occurred at all monitoring points. The propagation characteristics of shock waves is less affected by the pipeline network structure when it is close to the outlet of pipeline network. Nonlinear multivariate regression analysis was carried out to analyze the relationship between the overpressure attenuation coefficient and two adjacent monitoring points, the pressure before and after attenuation, and the pipeline angle. The functional relationship was in good agreement with the experiment data.