The deflagration suppression of methane-air by sodium salt-modified dry water: Experimental and kinetic investigation

To prevent explosion hazards of methane, the explosion suppression effects of dry water powder were enhanced using sodium salt (NaHCO₃, CH₃COONa, and NaH₂PO₄). The effects of different dry water on the pressure and time parameters of methane-air deflagration were tested experimentally. Meanwhile, a comprehensive reaction mechanism model of sodium salt dry water-methane combustion was established, revealing the thermal-chain synergistic explosion suppression mechanism of sodium salt dry water. The experimental results demonstrate that as the amount of sodium salt modified dry water increased, the pressure characteristic parameters of methane-air explosion decreased, and time characteristic parameters prolonged. Sodium bicarbonate-modified dry water exhibits the best suppression performance. The calculation of kinetics showed that adiabatic flame temperature and laminar burning speed decrease linearly with the increasing addition of sodium salt-modified dry water. The thermal characteristics show that the pyrolysis process of sodium salt dry water absorb heat and dilute the oxygen concentration of the deflagration process. Sodium-containing compounds react with H, O, and OH to form relatively stable NaOH. This compound inhibits chain reactions by suppressing both the net heat release and the production of critical free radicals within the system.The research results help to promote the safe use of methane energy.