Study on the shock wave and flame propagation characteristics of gas explosion in multi-branch tunnel network

To study the explosion shock wave propagation law and flame propagation mechanism within a multibranch complex tunnel network, we built a multibranch complex pipeline experimental system consisting of parallel and angular branches. Gas explosion overpressure peak, flame propagation time, light signal, and other factors are then investigated. The peak overpressure of the gas at 9.5 % concentration is 1.083 MPa. In the parallel branch, overpressure tends to decrease with increasing propagation distance. In the angular branch, the peak overpressure in the middle part of the angular branch is higher than that in the rest of the measurement points, maximum value of 0.769 MPa. The direction of flame propagation is affected by pressure. the flame is weak in the angular branch of the pipeline network, and the flame is mainly propagated along the parallel branch. The maximum propagation speed is 312.85 m/s. The explosion causes the gas to expand and heat up, and the turbulence generated by the high-temperature and high-pressure gas disturbance enhances the flame duration and flame light signal. The results of the study will provide a reference for the prevention of gas explosions and the design of coal mine roadways.