主管部门: 中国航天科技集团有限公司
主办单位: 中国航天空气动力技术研究院
中国宇航学会
中国宇航出版有限责任公司

滑动弧裂解CO2机理

Mechanism of CO2 Cracking by Gliding Arc

  • 摘要: 建立了一维滑动弧裂解CO2的反应机理模型. 利用对流冷却的特征频率计算横向气流对流引起的等离子体组分损失. 将等离子体密度和温度的数值模拟结果与文献中滑动电弧等离子体反应器的实验数据进行了对比,吻合较好. 模拟结果表明,滑动弧裂解CO2会产生大量O和O2等活性助燃粒子以及可燃的CO. 随着对流冷却特征频率的增加,放电过程中最大电子数密度和电子温度减小,CO2转化率下降. 在整个CO2裂解机制中e+CO2→e+CO+O的贡献最大,准稳态中贡献率为90.63%,瞬态中贡献率为98.43%. 反应CO+O+M→CO2+M对CO2生成的贡献率最大. 在实际应用中,为提高CO2转化率,可以通过增大放电电流,增大e+CO2→e+CO+O的反应速率,同时选择合适的气体流量,避免过大的速度引起CO2转化率下降.

     

    Abstract: In this paper, a one-dimensional gliding arc model and the detailed mechanism of CO2 cracking reaction were established. The characteristic frequency of convection cooling was used to calculate the plasma component loss caused by cross flow convection. The calculated plasma density and plasma temperature were compared with the experimental data of gliding arc plasma reactor in the literature. The calculation results show that a large number of active combustion supporting particles such as O and O2 and combustible CO gas will be produced during CO2 cracking by gliding arc. With the increase of the characteristic frequency of convection cooling, the maximum electron number density and electron temperature decrease, and the CO2 conversion rate decreases. The contribution rate of e+CO2→e+CO+O is the largest in the whole mechanism of CO2 cracking, which is 90.63% in quasi steady state and 98.43% in transient state. The contribution rate of CO+O+M→CO2+M to CO2 generation is the largest. In practical application, in order to improve the conversion rate of CO2, the discharge current and the reaction rate of e+CO2→e+CO+O should be appropriately increased. The gas flow rate should be appropriately selected to avoid the decline of CO2 conversion rate caused by excessive speed.

     

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