Experimental study on inhibition effect of inert gas parameters on gas deflagration flame propagation

In this paper, we continue to build an ultra-high speed laser schlieren testing system on the self-developed mesoscale explosion pipeline to explore the flame propagation characteristics of nitrogen and carbon dioxide inhibiting gas/air premixed gas deflagration under different injection positions and pressures. The results show that: in the experiment of inert gas inhibiting gas/air premixed gas deflagration, with the gradual increase of injection pressure, the flame propagation speed shows a trend of first increasing and then decreasing, the flame shape also gradually stretches and deforms from fingertip shape, and the middle protruding part becomes smaller until it is nearly flat; the maximum flame propagation speed of CO2 injection near the ignition end is 20.79% lower than that of N2 injection far away from the ignition end, and 20.25% lower than that of N2 injection; when CO2 is injected far from the ignition end, the minimum flame speed is 9.68% lower than that of CO2 injection, and 12.86% lower than that of N2 injection; compared with the two kinds of flame retarding and explosion inhibition gases, the highest flame propagation speed of CO2 sprayed near the ignition end is 21.78% lower than that of N2, and the lowest flame propagation speed is 1.82% lower than that of N2. The highest flame velocity and the lowest flame velocity are 21.25% and 5.27% lower than N2 when CO2 is sprayed at the far ignition end.