Study on flame propagation characteristics of coal dust explosion in horizontal straight pipe

Coal dust explosion is one of the common accidents in mines. The flame generated in the explosion process spreads rapidly, and the high-temperature flame will cause personal injury and equipment damage in the working environment. In order to study the flame propagation characteristics of coal dust explosion, four kinds of coal dust explosion flame propagation experiments were carried out by using the intelligent coal dust explosion identification device, and the flame propagation process was simulated by computational fluid dynamics(CFD) simulation. The results show that the flame length of lignite dust explosion is obviously longer than that of long flame coal, non-caking coal and gas coal. From the ignition of lignite coal dust, the flame length increases continuously, reaches the maximum of 52 cm at a certain time and then gradually decreases to 0. While the flame length increases, the flame propagation rate also experiences the propagation process of accelerating and decelerating. By comparing the explosion flame length obtained by CFD numerical simulation with the experimental results, it is found that the simulation error is within the acceptable range. Further statistical analysis is made on the simulation results of overpressure generated by explosion, and it is found that the change law is consistent with the theoretical formula, so as to further verify the feasibility of numerical simulation for explosion research. The research results lay a theoretical foundation for predicting the disaster scope of coal dust explosion accidents, and have practical significance for taking explosion suppression and flameproof measures in mines.