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甲烷燃烧具有环境污染小、放热量大等优点,但甲烷燃烧转化率受很多因素影响,因此,研究甲烷燃烧过程的转化率就显得尤为重要。基于计算流体力学中的涡耗散模型,运用有限容积法建立甲烷和空气非预混燃烧与扩散数学模型。针对具有3个小挡板,一个喷嘴的圆柱型燃烧器进行数值研究。结论:随着不同入口空气速度的逐渐增加,甲烷-空气非预混燃烧反应不充分,在轴向距离2 m处,反应生成的水和二氧化碳的含量逐渐减少,然而氧气增多,甲烷燃烧的转化率变低;随着不同入口甲烷速度的逐渐增加,甲烷-空气非预混燃烧反应充分,转化率变高;随着不同入口甲烷温度的增加,氧气浓度增加,甲烷-空气非预混燃烧反应不充分,转化率降低。
Methane combustion has the advantages of small environmental pollution and large heat release, but the methane combustion conversion rate is affected by many factors. Therefore, it is very important to study the conversion rate of methane combustion process. Based on the eddy dissipation model in computational fluid dynamics (CFD), a finite volume method was used to establish a non-premixed combustion and diffusion mathematical model of methane and air. A numerical study was performed on a cylindrical burner with three small baffles and one nozzle. CONCLUSION: With the gradual increase of inlet air velocities, methane-air non-premixed combustion reaction is not sufficient. At axial distance of 2 m, the content of water and carbon dioxide produced by the reaction decreases gradually. However, the increase of oxygen and the conversion of methane combustion With the inlet methane velocity gradually increasing, the methane-air non-premixed combustion reaction is full and the conversion rate is high. With the increase of the inlet methane temperature, the oxygen concentration increases and the methane-air non-premixed combustion reaction Inadequate conversion rate is reduced.