Experimental study on the explosive flame propagation of CH₄-O₂ in small scale pipeline

To study on the explosive flame propagation of CH₄-O₂ in small scale pipeline, a small scale pipeline experimental system was designed and built, including a small scale pipeline, gas distribution system, ignition system, explosive pressure data acquisition system, high-speed photography system and data processing system. The law of CH₄-O₂ explosion flame propagation under different initial pressure and initial concentration was studied by using small scale pipeline experiment system. The images collected by high-speed photography system were processed and calculated by the Matlab program to get the speed of explosive flame. The results show that, with the increase of the initial pressure, the maximum velocity of the explosive flame in the pipeline increases. The maximum velocity of the explosion in a pipe is linear with the reciprocal of the initial pressure. For different initial concentrations of mixed gas, there is a minimum initial pressure to form an accelerating flame. The minimum initial pressure to form an accelerating flame is smaller when the initial concentration is close to the equivalent concentration.