天然气-氢气-空气混合气的层流燃烧速度测定

在定容燃烧弹内研究了常温常压下天然气-氢气-空气混合气的火焰传播规律，得到了不同掺氢比例（氢气在天然气中的体积掺混比例为0％～100％）和燃空当量比（0．6～1．4）下混合气的层流燃烧速率和马克斯坦长度，通过对马克斯坦长度的测量，分析了拉伸对火焰传播的影响。结果表明，随着天然气中掺氢比例的增加，混合气的燃烧速率呈指数规律增加，马克斯坦长度值减小，火焰的稳定性下降。各掺氢比例下，随当量比的增加，马克斯坦长度值增加，火焰的稳定性增强。通过对试验结果的数据拟合，得到了计算天然气-氢气-空气混合气层流燃烧速率的关系式。

Measurements of Laminar Burning Velocities for Natural Gas-Hydrogen-Air Mixtures

The laminar flame characteristics of nature gas-hydrogen-air mixtures were studied in a constant volume combustion bomb at normal temperature and pressure.Laminar burning velocities and Markstein lengths were obtained at various ratios of hydrogen to natural gas(volume fraction form 0% to 100%) and equivalence ratios(from 0.6 to 1.4).The influences of stretch rate on flame propagation were also analyzed.The results show that laminar burning velocity increases exponentially with the increase of hydrogen fractions in the mixture, while the Markstein length decreases and flame instability increases with the increase of hydrogen fractions in the mixture.For a fixed hydrogen fraction,the Markstein length shows an increase and flame stability increases with the increase of equivalence ratios.Based on the experimental data,a formula for calculating the laminar burning velocities of natural gas-hydrogen-air mixture is proposed.