Effect of hydrogen enrichment and electric field on lean CH4/air flame propagation at elevated pressure

作     者：Wang, Jinhua Li, Yiming Xia, Hao Ju, Rongyuan Zhang, Meng Mu, Haibao Huang, Zuohua 

作者机构：Xi An Jiao Tong Univ State Key Lab Multiphase Flow Power Engn Xian 710049 Shaanxi Peoples R China Xi An Jiao Tong Univ State Key Lab Elect Insulat & Power Equipment Sch Elect Engn Xian 710049 Shaanxi Peoples R China 

出 版 物：《INTERNATIONAL JOURNAL OF HYDROGEN ENERGY》 (国际氢能杂志)

年 卷 期：2019年第44卷第30期

页      面：15962-15972页

核心收录：

学科分类：0820[工学-石油与天然气工程] 08[工学] 0807[工学-动力工程及工程热物理] 0703[理学-化学] 

基　　金：National Natural Science Foundation of China [51776164  51477135  91441203] 

主　　题：Hydrogen enrichment Electric assisted combustion Ionic wind Ion mole fraction Flame propagation Elevated pressure 

摘      要：Electric assisted combustion for hydrogen enriched hydrocarbons may even extend the lean burn limit and provide the further improvement on combustion stability. This study investigates the effect of hydrogen enrichment and DC electric field on lean CH4/air flame propagation. Electric field inside the chamber was generated by mesh and needle electrodes. Effect of hydrogen enrichment on the ion mole fraction in the flame was discussed based on reaction mechanism included neutral and ion reactions. The flame propagation images, flame displacement speed were used to evaluate the combined influences of hydrogen enrichment and electric field on propagating flame. Results showed that the hydrogen addition would increase positive ions mole fraction and the peak value is mainly determined by H3O+. This would be due to that CH increases with hydrogen fraction, which is the main species in the initial reaction for the ion reactions. Electric field effect about flame propagation was suppressed with hydrogen addition due to the competition between the increment in ion mole fraction and the decrement in flame time. Electric assisted combustion is more evident at leaner conditions and elevated pressure. The ratio of ionic wind velocity to flow velocity may be the determined factor to predict the electric field effect about propagating flame. The tendency based on this ratio is in accordance with the experimental results for various hydrogen fraction and equivalence ratio at elevated pressure. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.