【摘要】 通过定容燃烧弹试验结合一维层流预混火焰数值计算的方法，在初始压力为101.3 kPa，化学当量比为0.8～1.4，掺氢比为0.3～0.7的条件下，探究水蒸气含量（0～50%）对NH₃/H₂燃烧特性的影响机制。研究结果表明：随着当量比的增加，NH₃/H₂层流火焰速度先增大后减小，其峰值出现在当量比1.2左右。随着水蒸气稀释比增大，NH₃/H₂层流火焰速度线性降低，其峰值向当量比1.1偏移，且受当量比影响的敏感度降低。化学动力学分析表明在水蒸气的物理化学作用中，稀释作用的影响最大。主要基元反应中R1、R3、R68等支链反应对层流火焰传播具有促进作用，而R16、R58、R60等支链反应具有抑制作用。提高水稀释比会增加关键支链反应对层流火焰速度的敏感性系数，并且其增加的幅度不断变大。随着水稀释比不断增加，反应区的NO、N₂O、OH等自由基的物质的量分数显著降低，导致NH₃/H₂层流火焰速度降低。更多还原

【Abstract】 The mechanism of the influence of water vapor dilution（0～50%） on the combustion characteristics of NH₃/H₂ was investigated under the conditions of initial pressure of 101. 3 kPa, chemical equivalence ratio of 0. 8～1. 4 and hydrogen blending ratio of 0. 3～0. 7, by the method of a constant volume combustion bomb experiment together with the method of one-dimensional laminar premixed flame numerical calculation. The results show that the laminar flame speed of NH₃/H₂ first increased and then decreased with the increase of equivalence ratio, with a peak appearing around 1. 2 equivalence ratio. As the dilution ratio of water vapor increased, the laminar flame speed of NH₃/H₂ decreased linearly, and its peak shift towards the equivalence ratio of 1. 1, and the sensitivity affected by the equivalence ratio decreased. The chemical kinetic analysis result shows that the dilution effect has the greatest impact among different physical and chemical effects of water vapor. The branch chain reactions such as R1, R3, and R68 promote laminar flame propagation, while branch chain reactions such as R16, R58, and R60 have the opposite effect. A higher water dilution ratio increases the sensitivity coefficient of critical branch chain reactions to laminar flame speed, and the growth trend of sensitivity coefficient continues to increase. With the increase of the water dilution ratio, the molar fractions of free radicals such as NO, N₂O, OH in the reaction zone significantly decrease, leading to a decrease in the laminar flame speed of NH₃/H₂.更多还原