Abstract: In order to know further about the inhibitory effect of ultrafine water mist on explosion of mixture of air and methane, a small size and semi-closed visual experimental platform was built, and experiments were carried out by using the platform. Four factors including the volume of the ultrafine water mist sprayed, the volume fraction of methane, the position where methane was pumped into and the premixed time were taken into consideration, and single factor experiments and the orthogonal experiments were carried out. The authors have come to the conclusion that ultrafine water mist can inhibit explosion of mixture of air and methane effectively, especially that of the mixture with 9.5% methane, there is a positive correlation between the volume of the ultrafine water mist and the inhibitory effect, that the volume fraction of methane has a remarkable influence on maximum explosion overpressure (ΔP_max) of methane explosion, and the volume of ultrafine water mist sprayed has a certain influence on it, and that the volume of ultrafine water mist has a remarkable influence on the spreading time of fire in methane explosion,and the volume fraction of methane has a certain influence on the spreading time.

Key words: ultra-fine water mist, methane, inhibition, single factor, orthogonal experiment, pressure, flame propagation