燃烧模型对多孔介质内预混燃烧的影响

采用二维非稳态数学模型研究燃烧模型多孔介质内预混燃烧影响.燃烧模型分别为单步和多步化学反应动力机理（17种组分,58个反应）,CH4/空气当量比的范围为0.55～1.0.对比分析两种燃烧模型下燃烧器中心处的温度、组分浓度分布曲线.结果表明,多步燃烧模型对燃烧器内温度、组分浓度分布有更准确的预测,并与文献结果比较,证实了二维非稳态数学模型的正确性.此外,将二维的温度场进行比较,结果表明单步化学机理的反应区域小,温度梯度大,而多步化学反应由于各反应步骤存在时间尺度的差异,反应区域大,温度梯度相对较小,与实际燃烧情况能很好的吻合.

Effect of Combustion Model on Premixed Combustion within Porous Media

The effect of combustion model on premixed combustion within porous media is investigated by using twodimensional unsteady mathematical model. The combustion models include single-step and multi-step （17 species ,58 reaction steps） reaction kinetics mechanisms and methane/air equivalence ratios （Ф） range from 0.55 to 1.0. The calculated data of temperature and species concentration profiles on the centerline of burner are analyzed and compared for different combustion models, The results indicate that the predictions of both temperature and species concentration are more accuratewhen using multi-step chemical reaction mechanism. And the data are also compared with the results from literatures, two-dimensional unsteady model is validated. Moreover, the comparisons made in two-dimensional temperature field show that, for single-step reaction, the temperature gradient is larger and reaction zone is smaller, while for multi-step reaction, the temperature gradient is smaller and reaction zone is larger due to the difference of time scale, and the temperature field for multi-step reaction is in good agreement with the actual situations.