The Flame Stability of Methane-Oxygen Laminar Diffusion under High-Voltage Direct Current Field
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摘要: 设计开发了直流电场作用下层流火焰实验系统，通过对甲烷-氧气非预混层流火焰施加直流电场，改变电极间距及燃烧当量比，对高速相机下火焰脉动幅度受电场影响的变化规律进行分析，探究了直流电场对火焰稳定性的作用及电场约束火焰的可行性。结果表明，对于存在脉动的层流扩散火焰，当对其施加高压直流电场时，火焰受到离子风的作用，其脉动幅度会逐渐减弱直至趋于稳定状态，且火焰稳定时所对应的电场强度与其初始的脉动幅度有关，初始振幅越大火焰稳定所需的电压越高。同时，电极间距的改变也会影响火焰稳定时所需的电场强度，当电极间距改变较大时，对同一当量比的火焰，间距越大所需的稳定电压就越高。Abstract: For coal gasification technology, a general flame control technology is needed to ensure the stable combustion in the gasification furnace. And in the combustion process, the flame will produce huge amounts of charged particles, so that the flame has electrical properties, and can be affected by the electric field. In this study, a laminar flame experimental system under direct current electric field was designed and developed. A direct current electric field was applied to a methane-oxygen non-premixed laminar flame. Then the electrode spacing of DC electric field and the combustion equivalent ratio of the laminar flame would be changed. The high-speed camera was use to record the rule of flame pulsation affected by the DC electric field. The effect of direct current electric field on flame stability was explored, and the feasibility of using electric field to confine the laminar flame was verified. The results show that, when high voltage direct current is applied to the flame, the laminar diffusion flame pulsation will be influenced by the effect of ion wind. The amplitude of flame pulsation will gradually diminish until the flame is in a steady state, and the electric field intensity which can stabilize the flame is associated initial pulse amplitude. The higher the initial amplitude is, the greater the voltage will be demanded. At the same time, the change of electrode spacing will also affect the electric field intensity required for flame stability. When the electrode spacing changes greatly, for the flame with the same equivalent ratio, the larger the distance is, the higher the stable voltage will be required.
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Key words:
- DC electric field /
- diffusion flame /
- Ionic wind effect /
- flame stability
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图 2 未施加电场时的火焰高度变化
Figure 2. Flame height change without electric field (equivalent ratio λ=1,
$ {{Q}}_{{\rm{CH}}_4} $ =0.25 L/min,$ {{Q}}_{{\rm{O}}_2} $ = 0.50 L/min)
图 3 未施加电场时的火焰振荡情况
Figure 3. Flame pulsation without electric field (equivalent ratio λ=1,
$ {{Q}}_{{\rm{CH}}_4} $ = 0.25 L/min,$ {{Q}}_{{\rm{O}}_2} $ = 0.50 L/min)
图 4 火焰振荡幅度随当量比变化趋势
Figure 4. The variation trend of flame pulsation amplitude with equivalent ratio
图 5 火焰振荡情况与直流电压的关系
Figure 5. Relationship between flame pulsation and DC voltage (
$ {{Q}}_{{\rm{CH}}_4} $ = 0.25 L/min,$ {{Q}}_{{\rm{O}}_2} $ = 0.50 L/min)
图 6 火焰振荡能谱图与直流电压的关系
Figure 6. Relationship between flame pulsation energy spectrum and DC voltage (
${{Q}}_{{\rm{CH}}_4} $ = 0.25 L/min,${{Q}}_{{\rm{O}}_2} $ = 0.50 L/min、λ=1)
图 7 不同电极间距下火焰稳定电压随当量比的变化
Figure 7. Variation of flame stable voltage with equivalence ratio at different electrode spacing
图 8 各电极间距下初始振幅与稳定电压的关系（λ=1.00~1.30）
Figure 8. Relationship between initial amplitude and stable voltage at different electrode spacing (λ=1.00~1.30)
表 1 电场对扩散火焰实验条件
Table 1. Experimental conditions of electric field on diffusion flame
Condition Electrode spacing/cm Methane flow rate/(L·min−1) Oxygen flow rate/(L·min−1) Argon flow rate/(L·min−1) 1 8.0 0.25 0.50 0.50 2 0.55 3 0.60 4 0.65 5 0.70 6 0.75 7 0.80 8 9.0 0.25 0.50 0.50 9 0.55 10 0.60 11 0.65 12 0.70 13 0.75 14 0.80 15 10.0 0.25 0.50 0.50 16 0.55 17 0.60 18 10.0 0.25 0.65 0.50 19 0.70 20 0.75 21 0.80 22 11.0 0.25 0.50 0.50 23 0.55 24 0.60 25 0.65 26 0.70 27 0.75 28 0.80 29 12.0 0.25 0.50 0.50 30 0.55 31 0.60 32 0.65 33 0.70 34 0.75 35 0.80 
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[1] 国务院发展研究中心资源与环境政策研究所. 中国能源革命进展报告(2020)[M]. 北京: 石油工业出版社, 2020.10. [2] 谢克昌. 科学认识煤化工 大力推进煤的清洁高效利用[J]. 能源与节能, 2011(2): 2. [3] 王辅臣. 煤气化技术在中国: 回顾与展望[J]. 洁净煤技术, 2021, 27(1): 33. [4] KWONG K, PETTY A, BENNETT J, et al. Wear Mechanisms of Chromia Refractories in Slagging Gasifiers[J]. International Journal of Applied Ceramic Technology, 2010, 4(6): 503-513. [5] GONG Y, GUO Q, ZHU H, et al. Refractory failure in entrained-flow gasifier: Investigation of partitioned erosion characteristics in an industrial opposed multi-burner gasifier[J]. Chemical Engineering Science, 2019, 210: 115227. doi: 10.1016/j.ces.2019.115227 [6] CALCOTE H F, PEASE R N. Electrical properties of flames. burnerFlames in longitudinal electric fields[J]. Industrial & Engineering Chemistry, 1951, 43(12): 2726-2731. [7] WEINBERG J. Maximum ion currents from flames and the maximum practical effects of applied electric fields[J]. Proceedings of the Royal Society of London Series A, Mathematical and Physical Sciences, 1964, 277(1371): 468-497. [8] RICHARD, GILDART, FOWLER S, CORRIGAN J. Burning-wave speed enhancement by electric fields[J]. Physics of Fluids, 1966: 9. [9] 房建峰, 赵海军, 周辉, 等. 电场对甲烷-空气混合气燃烧特性的影响[J]. 化工学报, 2018, 69(10): 4409-4417. [10] SAYED-KASSEM A, GILLON P, IDIR M, et al. On the Effect of a DC electric field on soot particles' emission of a laminar diffusion flame[J]. Combustion Science and Technology, 2019: 1-12. [11] JING H, RIVIN B, SHER E. The effect of an electric field on the shape of co-flowing and candle-type methane–air flames[J]. Exp Thermal Fluid, 2000, 21(1/3): 124-133. doi: 10.1016/S0894-1777(99)00062-X [12] 王美. 乙醇小尺度射流扩散火焰稳燃及电学特性的研究[D] 广州: 华南理工大学, 2014. [13] 卢矍然, 高忠权, 何子奇, 等. 直流电场对甲烷/空气预混火焰影响的机理研究[J]. 西安: 西安交通大学学报, 2020, 54(03): 88-96. [14] LEWIS, BERNARD. The effect of an electric field on flames and their propagation[J]. Journal of the American Chemical Society, 2002, 53(4): 1304-1313. [15] DLW A, SDM A, BNG B. Electrical control of the thermodiffusive instability in premixed propane: air flames[J]. Combustion and Flame, 2007, 151(4): 639-648. doi: 10.1016/j.combustflame.2007.06.021 [16] KIM M K, RYU S K, WON S H, et al. Electric fields effect on liftoff and blowoff of nonpremixed laminar jet flames in a coflow[J]. Combustion & Flame, 2010, 157(1): 17-24. [17] DAE, GEUN, PARK, et al. Soot reduction under DC electric fields in counterflow non-premixed laminar ethylene flames[J]. Combustion Science and Technology, 2014, 186(4-5): 644-656. doi: 10.1080/00102202.2014.883794 [18] BELHI M, DOMINGO R, VERVISCH R. Direct numerical simulation of the effect of an electric field on flame stability[J]. Combustion & Flame, 2010, 157(12): 2286-2297. [19] 王宇, 姚强. 电场对火焰形状及碳烟沉积特性的影响[J]. 工程热物理学报, 2007(S2): 237-239. doi: 10.3321/j.issn:0253-231X.2007.z2.063 [20] VAN DEN BOOM J D B J, KONNOV A A, VERHASSELT A M H H, et al. The effect of a DC electric field on the laminar burning velocity of premixed methane/air flames[J]. Proceedings of the Combustion Institute, 2009 2009/01/01/, 32(1): 1237-1244. [21] MORIYA S, YOSHIDA K, SHOJI H, et al. The effect of uniform and non-uniform electric field on flame propagation[J]. Nihon Kikai Gakkai Ronbunshu B Hen/transactions of the Japan Society of Mechanical Engineers Part B, 2008, 3(2): 254-265. [22] 唐安东, 孟祥文, 周蓉芳, 等. 非均匀电场对火焰传播速率的影响[J]. 西安: 西安交通大学学报, 2012, 46(09): 16-20. [23] 孟祥文, 杨星, 康婵等. 直流电场对预混CH4/O2/N2火焰传播特性影响的试验研究[J]. 西安: 西安交通大学学报, 2013, 47(07): 13-17. [24] 康婵, 杨星, 刘杰, 等. 负电场下点电极和网状电极对预混稀燃火焰的影响[J]. 西安: 西安交通大学学报, 2014, 48(01): 31-36. [25] 段浩, 房建峰, 孙天旗, 等. 不同电极结构下电场对甲烷/空气火焰的影响[J]. 西安: 西安交通大学学报, 2014, 48(09): 62-67. doi: 10.7652/xjtuxb201409011 [26] SAYED-KASSEM A, ELORF A, GILLON P, et al. Numerical modelling to study the effect of DC electric field on a laminar ethylene diffusion flame[J]. International Communications in Heat and Mass Transfer, 2021 2021/03/01/, 122: 105167. [27] 汪军, 马其良, 张振东. 工程燃烧学[M]: 工程燃烧学 2008. [28] TURNS S R. 燃烧学导论[M]: 燃烧学导论 2009. -
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