摘要
实验研究不同初始温度下掺氢天然气可燃下限变化规律,分析初始温度对掺氢天然气近极限预混燃烧影响机制,并利用Le Chatelier及Kondo公式对掺氢天然气可燃下限进行理论计算.研究发现,掺氢天然气可燃下限随掺氢比增加逐渐下降,高温下这种变化趋势更显著;掺氢天然气可燃下限随初始温度升高近线性下降,高温下H自由基摩尔分数的升高显著增强H+O_(2)=O+OH对近极限预混燃烧过程的主导促进作用.Le Chatelier公式能较准确预测掺氢天然气可燃下限随掺氢比变化规律.当掺氢比较低时,Kondo公式能较准确预测掺氢天然气可燃下限随初始温度近线性变化趋势,但当掺氢比和初始温度较高时,掺氢天然气近极限预混燃烧过程主导反应及重要自由基摩尔分数显著变化,使其预测结果准确性显著降低.
The lower flammability limits of H_(2)/CH_(4)mixtures over a wide range of H_(2)fractions are systematic experimentally studied at various initial temperatures.The effect of initial temperatures on the near‑limit flames of H_(2)/CH_(4)mixtures is insightfully discussed.In addition,the estimations of the lower flammability limits of H_(2)/CH_(4)mixtures is also calculated using Le Chatelier rule and Kondo’s correlation.The results show that the lower flammability limits of H_(2)/CH_(4)mixtures decrease with the growth of H_(2)fractions under all measured initial temperatures.The greater declines of lower flammability limits are presented at higher initial temperatures.Moreover,the lower flammability limits of H_(2)/CH_(4)mixtures almost linearly decrease with the increase of initial temperatures.Under the higher initial temperatures,the dominant promotion of H+O_(2)=O+OH on the near-limit flames of H_(2)/CH_(4)mixtures is enhanced by the significant increase of H radicals.The comparison between the experimental data and calculation results shows that Le Chatelier rule presents satisfactory applications on estimating lower flammability limits of H_(2)/CH_(4)mixtures based on the accurate measurements.Kondo’s correlation provides the greater accurate predictions on the linear temperature dependence of the lower flammability limits of mixtures with lower H_(2)fractions.However,the considerable distinctions between experimental data and calculation results using Kondo’s correlation at higher H_(2)fractions under elevated initial temperatures are attributed to the significant variation of the sensitivity of dominant reactions and the mole fractions of vital radicals.
作者
尚融雪
孙浩英
庄紫喧
李刚
SHANG Rong-xue;SUN Hao-ying;ZHUANG Zi-xuan;LI Gang(School of Resources&Civil Engineering,Northeastern University,Shenyang 110819,China)
出处
《东北大学学报(自然科学版)》
CSCD
北大核心
2024年第11期1638-1644,共7页
Journal of Northeastern University(Natural Science)
基金
国家自然科学基金资助项目(51804065)
中国博士后科学基金资助项目(2018M631811)。
