Abstract The laminar burning velocities (LBVs) of seven different composition stoichiometric mixtures (CO: 15%–20%, H2: 5%–20%, CH4: 5%–15%, CO2: 15%, N2: 50%) under different oxygen levels (O2: 21%–60%) were experimentally measured by spherical expansion flame method. Numerical calculations were conducted with the PREMIX code using seven detailed chemical reaction mechanisms (FFCM-1, GRI 3.0, USC-Ⅱ, San Diego + NOx, HP-mech, Li-2015, CRECK + NOx) and compared with experimental data. The CRECK mechanism provides an over-prediction of the LBV of CH4-free mixtures. San Diego is more prominent than CRECK with the addition of CH4, followed by GRI 3.0 and HP-mech. Three mechanisms—FFCM-1, Li-2015, USC-Ⅱ—that matched the experimental results well were chosen to perform the LBV calculations for a wider range of initial conditions (Φ: 0.6–1.6, Tu: 300 and 400 K, P0: 1 and 3 atm) for variable composition mixtures. The results show that for all cases, the LBV is considerably increased with increasing oxygen concentration. CH4-rich mixtures are more sensitive to oxygen concentrations and work to increase the LBVs mainly through thermal effects. An oxygen-rich environment makes the flammability limit wider even with high initial pressure. H2-rich mixtures accompanied by higher thermal diffusivity are more susceptible to the initial temperature, while chemical effects do not dominate in oxygen-rich environments. In oxygen-rich environments, diffusional-thermal instability is suppressed while the cellular structure of the flame is mainly affected by fuel composition and hydrodynamic instability. The formation of NO in flames of different composition mixtures in an oxygen-rich environment was analyzed.

中文翻译：

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富氧空气对生物质合成气层流燃烧特性影响的实验与数值研究

摘要 七种不同组成化学计量混合物（CO：15%–20%，H2：5%–20%，CH4：5%–15%，CO2：15%，N2：50%）的层流燃烧速度（LBVs）不同的氧气含量（O2：21%–60%）通过球形膨胀火焰法进行实验测量。使用七种详细的化学反应机理（FFCM-1、GRI 3.0、USC-Ⅱ、San Diego + NOx、HP-mech、Li-2015、CRECK + NOx）使用 PREMIX 代码进行数值计算，并与实验数据进行比较。CRECK 机制提供了对不含 CH4 混合物的 LBV 的过度预测。圣地亚哥比 CRECK 更突出，添加了 CH4，其次是 GRI 3.0 和 HP-mech。选择了与实验结果很好匹配的三种机制——FFCM-1、Li-2015、USC-Ⅱ——在更广泛的初始条件（Φ：0.6-1.6，Tu：300 和 400 K，P0：1 和 3 个大气压）用于可变成分混合物。结果表明，对于所有情况，LBV 都随着氧气浓度的增加而显着增加。富含 CH4 的混合物对氧浓度更敏感，主要通过热效应来增加 LBV。即使在高初始压力下，富氧环境也会使可燃性极限更宽。伴随着较高热扩散率的富 H2 混合物更容易受到初始温度的影响，而在富氧环境中，化学效应并不占主导地位。在富氧环境中，扩散热不稳定性受到抑制，而火焰的细胞结构主要受燃料成分和流体动力学不稳定性的影响。