天然气/氢气燃烧特性研究

在定容燃烧弹中研究了不同氢气掺混比例、燃空当量比和初始压力下的大然气／氢气混合气的燃烧特性，建立了适合用于容弹计算的准维双区模型。研究结果表明：在各种当量比和初始压力下，随着掺氢比例的增加，混合气的质量燃烧速率明显增加，燃烧持续期和火焰发展期娃著缩短。随着掺氢比例的增加，短的燃烧持续期所对应的当量比范围变宽，稀混合气和浓混合气条件下天然气掺氢对火焰发展期缩短的效果更明显。化学计量比附近（1．0—1．1）掺氢燃烧对燃烧最大压力值影响不大，浓混合气（燃空当量比大于1．1）和稀混合气燃烧时，随着掺氢比例的增加，最大燃烧压力值增加。

Study on Combustion Characteristics of Natural Gas-Hydrogen-Air Mixtures

The combustion characteristics of natural gas-hydrogen-air mixtures were studied in a constant volume bomb under various ratios of hydrogen to natural gas, equivalence ratios and initial pressures. Meanwhile, a two-zone model was proposed for predicting combustion parameters based on the pressure data. The study shows that, with the increase of hydrogen fraction in mixture, the normalized mass burning rate will increase and the flame development duration and combustion duration will decrease at various equivalence ratios and initial pressures. Little influence of hydrogen addition on the maximum combustion pressure is found at the equivalence ratios near to the stoichiometric equivalence ratio. However, for lean mixture combustion and rich mixture combustion, the maximum combustion pressure will increase with the increase of hydrogen fraction in mixture. Moreover, wide ranges of equivalence ratio for getting shorter combustion duration are presented with the increase of hydrogen fraction in mixture. The decrease in flame development duration shows more obviously at lean mixture combustion and rich mixture combustion.