Experimental study on the effectiveness of new core-shell structure extinguishant to extinguish oil pool fire and analysis of fire extinguishing mechanism

To investigate the feasibility and extinguishing performance of clean extinguishing agent dry water materials for oil fires, the properties of dry water materials and dry water materials with different additives were characterized in terms of bulk density, water retention, fluidity, and particle size distribution. Autonomous fire suppression platforms were built to investigate the efficacy and effect of different dry water additive concentrations on the suppression of oil fires. Thermogravimetric analysis was performed on dry water samples with good extinguishing efficacy. The results showed that the dry water samples containing additives had faster extinguishing times, lower extinguishing doses, and faster temperature drop rates than dry water samples. For different concentrations of dry water samples, the dry water sample containing 8% sodium acetate had the fastest extinguishing time of 4.1 s, the lowest dose of 96.3 g, and the fastest temperature drop rate of 15.7 degrees C s-1, followed by the dry water sample containing 0.4% urea. Combined with thermogravimetric analysis and kinetic calculations, the dry water samples containing urea and sodium acetate additives possessed activation energies of 36.44 kJ mol-1 and 37.75 kJ mol-1, respectively. The activation energies of the dry water samples with the additives were more than 20% lower than those of DW1. Dry water samples with additives all provide better fire suppression, suppressing flames, and controlling flame spread by cooling, diluting oxygen, reducing activation energy, and trapping free radicals.