Comparative experimental study on inhibition of methane explosion by ultra-fine water mist containing different additives

Abstract

This study utilized a 2.5L visual pipeline experiment platform to investigate the inhibitory effect of ultra-fine water mist containing different additives on methane explosion. It provides a more comprehensive experimental foundation for the subsequent research on methane explosion suppression. The experiment analyzed the particle size parameters of ultra-fine water mist and the effect of different additives on the inhibition of pipeline methane explosion. The results showed that the explosion overpressure of ultra-fine water mist containing KBr, FeCl2, and PPFBS was significantly lower than that of pure methane and pure water ultra-fine water mist with the same amount of spray. The best inhibition effect was observed with 5% KBr, 0.82% FeCl2, and 0.07% PPFBS. Compared to 5 mL pure water mist, the explosion overpressure decreased by 19.49%, 16.87%, and 46.3%, and the flame propagation speed decreased by 18.7%, 15.55%, and 41.65%, respectively. It is proved that the listed additives have different degrees of inhibiting effects on methane explosion. The composite additive ultra-fine water mist had a greater effect on temperature and reacted with a large number of free radicals such as H and O, which hindered the chain reaction in the process of methane combustion most obviously. The four additives have the best explosion suppression effect: compound additive, PPFBS, KBr, and FeCL2. The main mechanism of the effect of different inorganic salt additives is that the ultra-fine water mist cools the reaction zone's temperature, and affects the gas's volume ratio after dilution and vaporization, and some evaporated crystals also play the role of attenuating heat radiation.