Investigation on the synergistic suppression effect of flame retardant-modified dry water on methane explosion

To reduce the occurrence of methane (CH 4 ) explosion accidents, this study successfully prepared a novel composite powder (CGDW) by adding magnesium hydroxide and zinc borate to the core solution of dry water (DW). Its physical properties, such as flowability, mechanical stability, particle size distribution, water retention, and bulk density were characterized separately. The effect of CGDW on the explosion characteristics of stoichiometric CH 4 was explored in a square explosion pipeline. The results showed that the physical properties of CGDW were significantly improved compared to DW. CGDW demonstrated excellent CH 4 explosion suppression performance due to its unique core-shell structure, which could simultaneously exert a solid-liquid two-phase suppression effect. After adding 15 g CGDW, the maximum explosion pressure decreased by 69.4 %, the peak temperature decreased by 97.8 %, and the explosion flame was isolated during propagation. In addition, the explosion suppression mechanism of CGDW on the CH 4 was explored in terms of physical effects (heat insulation, gas dilution, cooling) and chemical effects (interrupting the chain reaction). CGDW possesses green and high-efficiency characteristics, providing a new path to suppress CH 4 explosion and improve the safety of its usage.