Suppressive effects of alkali metal salt modified dry water material on methane-air explosion

As an abundant and efficient energy source, methane has a wide range of applications and development prospects, but it has a high explosion risk. In order to prevent the occurrence of methane explosion accidents, a new type of dry water material (DW) was used to suppress explosion, and alkali metal salts were added to improve the suppression effect. In this work, the optimal DW with complete monomer and uniform structure can be prepared by stirring nano-silica and deionized water at a mass ratio of 1:10 at a speed of 10000 rpm for 60S. The suppression effect of dry water was analyzed by performing methane-air explosion experiments with different powder concentrations in 20L explosion vessel. The results show that under the action of alkali metal modified DW, the Pmax and the deflagration index KG of methane-air explosion were significantly reduced. The improvement effect of potassium salt-dry water (PS-DW) ranked as KCl> K2CO3> K2C2O4·H2O>CH3COOK, and the improvement effect of sodium salt-dry water (SS-DW) ranked as Na2CO3>NaCl > NaHCO3>NaH2PO4. Moreover, the explosion suppression mechanism of alkali metal salt modified DW was analyzed from four aspects: heat insulation, cooling, dilution and interruption of chain reaction. The study confirmed the important application potential of DW in preventing natural gas leakage explosion and coal mine gas explosion accidents. The optimal selection of modified additives in alkali metal salts holds significant importance for the widespread application of novel dry water composite materials.