Explosion behavior of premixed hydrogen/ammonia/air mixtures with the addition of N2 and CO2

The effects of adding N2 and CO2 on the explosion behavior of premixed hydrogen/ammonia/air mixtures were investigated through experiments and analysis of reaction kinetics. The effects of N2 and CO2 on the evolution of the flame structure, flame front speed, pressure and reaction kinetics were analyzed. The results indicated that increasing the hydrogen fraction in the fuel can accelerate the premixed flame, leading to higher flame front speeds and increased pressure. Conversely, the addition of N2 and CO2 has a suppressive effect. This suppression effects of N2 and CO2 diminished as the hydrogen content in the fuel increased. The suppression of N2 and CO2 is primarily due to the effect on the consumption rates of key free radicals. CO2 has a stronger suppressive effect than does N2 because it can directly participate in combustion reactions and consume key free radicals. The findings of this study provide a basis for the safe use of hydrogen-ammonia.