Effect of the opening scale of the obstacle plate on the flame behavior of non-uniform and uniform combustible gases

Coal is an indispensable fuel and plays an important role in the energy industry. However, coal mining is often accompanied by disasters such as gas explosion, which impose severe restrictions on the efficient exploitation of coal resources. The non-uniformity of combustible gases and obstructions in space are important factors that affect the intensity of explosions. In this study, an experimental investigation of non-uniform and uniform methane–air flame behavior in a duct containing obstacles with different opening scales was investigated. The results showed that for non-uniform methane–air mixtures, the speed of the velocity change under different opening scale obstacle configurations varied owing to the degree of non-uniformity. In addition, the explosion overpressure curves exhibited significant pressure peaks at extended diffusion times, with the largest pressure peak in the configuration with a barrier-opening scale of 50 mm. Furthermore, the backflow phenomenon after the flame passed through the obstacle only appeared in configurations with larger obstacle-opening scales or diffusion times. These findings offer insights into the prevention and management of gas explosions in coal mining and contribute to the efficient and safe development of coal resources.