Abstract: The effects of variable velocity on the explosion flame propagation characteristics and explosion overpressure characteristics of methane/air mixed fuel were studied by a self-built visual methane explosion experiment platform with a variable velocity small fan installed at the end of the pipeline to produce premixed gas flow with the same and opposite flame propagation direction. The results show that variable velocity gas flow can promote methane explosion combustion to some extent. With the increase of gas velocity, the effect of promoting methane explosion combustion gradually increases. However, with the increase of gas velocity, for single-phase convection gas, the effect of promoting methane explosion begins to decrease with the increase of opposite flow intensity. For a single homogeneous flow gas, with the increase of the intensity of the flow, it has been shown to promote the explosion of methane. At the same time, the flame oscillates when approaching the tail fan.

Key words: methane explosion, air velocity, flame image, flame velocity, explosion overpressure