Study on the explosion suppression efficiency and mechanism of modified dry water material in ammonia-hydrogen-air mixture

Abstract

Ammonia-hydrogen mixture is a promising zero-carbon fuel, but its production, storage, transportation, and utilization processes carry significant explosion risks. This study aims to prepare modified dry water (KMDW) by compounding different potassium salts with melamine polyphosphate (MPP) and investigate their suppression performance on ammonia-hydrogen mixture (40 % H 2 ) explosions at various equivalence ratios using experiments and simulations. In experiments, it can be found that all KMDW outperformed unmodified dry water, with KMDW-KCl exhibiting the best performance. With 12 g of KMDW-KCl, the peak flame temperature and explosion pressure were significantly reduced by 96.5 % and 82.6 % at φ = 1.0, and the flame was quenched 1.4 m from the ignition end. Furthermore, its suppression effectiveness was found to be applicable across a wide range of equivalence ratios. Simulation analysis revealed that the potassium and phosphorus containing active species released from KMDW-KCl decomposition interrupt the chain reactions by scavenging key radicals such as H and OH, with R968 (KOH + H = K + H 2 O) and R964 (KO 2 + OH = KOH + O 2 ) identified as the dominant elementary reactions for explosion suppression. These results provide critical data and a theoretical basis for the safe utilization of ammonia-hydrogen mixed fuels and offer new insights for developing highly efficient explosion suppressants.