Abstract: In this paper, the inhibitory effect of silica composite ammonium polyphosphate additives on the propagation of premixed explosions is investigated by experimental methods. The hydrogen blending ratio for premixed gas fuels is 20%. The concentration of the compound inhibitor is 0.5 g/L, with 3 kinds of mass ratios. The experimental results show that the composite additive has a significant inhibitory effect on the propagation of hydrogen-methane explosions and it can limit the expansion of the explosion flame in the early stage. The additive absorbs heat and decomposes during the middle and late stages of the explosion development, reducing the amount of heat released from the explosion flame, as well as impeding the transfer of heat between the flame and the fuel, and disrupting the chain reaction process of the original explosion system by the decomposition products. The flame speed under the influence of composite explosion suppressant decreased by a maximum of 91%, greatly attenuating the accumulation and release of pressure. The explosion development process is effectively limited.

Key words: premixed flame, hydrogen-methane, explosion suppression, flame deceleration