Abstract: Abstract: To study the explosion suppression technology of the hydrogen?doped natural gas in the pipeline, in a customized 100 mm×100 mm×1 000 mm plexiglass pipe, the synergistic effect of using porous media and CO2 to suppress the methane explosion with a hydrogen content ratio of 10% was studied, and the effect of synergistic CO2 on the different stages of flame development and the change of jet position on the explosion was explored. The results indicate that when the porous medium cooperates with CO2 at different stages of flame development, the left side wall attached CO2 jet cannot successfully quench the flame at the porous medium. When CO2 acts on the fingertip flame and the flame front is directly below the nozzle,it has a significant inhibitory effect on the flame propagation. However, the CO2 right side wall attached jet can successfully block flame propagation and has a good inhibitory effect on peak flame velocity, average flame velocity, and explosion overpressure peak. This indicates that the gas-solid dual explosion suppression mechanism of porous media cooperating with CO2 is better than that of a single porous medium, providing a theoretical reference for the composite explosion suppression technology of hydrogen-doped natural gas pipeline engineering.

Key words: CO2 , porous media, low hydrogen ratio methane, collaborative explosion suppression