激光激活气体反应分子助燃CH_4/O_2/N_2燃烧的数值研究
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摘要
目前能源危机中能源利用效率低的现状以及航空动力学中超燃冲压发动机研制所面临的稳定燃烧困难问题,对燃料的燃烧速率和效率提出了更高的要求,针对此问题,本文提出了飞秒激光诱导等离子助燃技术。通过飞秒激光诱导产生的等离子体中存在着大量的激发态组分和自由基,这些活性粒子的存在增加了燃烧链式反应的速率,从而可以提高火焰传播速度,实现助燃的效果。
本文首先分析了激光激活气体反应分子助燃的可行性,在CHEMKIN软件中,利用层流预混火焰传播速度计算器模块并结合飞秒激光作用下的甲烷燃烧机理,建立起了飞秒激光激活气体反应分子的助燃模型。通过该模型分析了激光诱导等离子产生的几种活性组分对层流预混火焰的影响。最后通过敏感性分析并结合产物生成速率分析的方法对O和O_2(a~1Δ_g)的助燃机理进行了分析。
通过模拟分析发现,预混气体中O、O3的存在都可以在整个当量比的范围内提高火焰传播速度以及H、O、OH组分的浓度,实现助燃的效果。CH_3和CH_2只对当量比小于一定界限的贫燃料火焰才具有助燃作用。激发态组分O_2(a~1Δg)和O_2(b~1Σ_g~+)的存在都可以明显提高火焰传播速度和H、O、OH的浓度,但是O_2(a~1Δ_g)的助燃效果不如O_2(b~1Σ_g~+)明显。分析发现,N_2(A~3Σ_u~+)和O_2作用时可以将O_2激发为O_2(a~1Δ_g)、O_2(b~1Σ_g~+)或者解离为O,实现对层流预混火焰的助燃效果,同时N_2(A~3Σ_u~+)还可以和H2作用将其解离为H,通过提高预混气体中H的浓度而实现助燃。
通过对甲烷燃烧机理分析发现,H+O_2(?)O+OH这个反应是层流预混火焰中控制火焰传播速度和H、O、OH组分浓度的最重要的反应。预混气体中O和O_2(a~1Δ_g)的存在增加了火焰传播速度敏感性为正的反应的正向反应速率以及火焰传播速度敏感为负的反应的逆向反应速率,因此使得火焰传播速度得到提高,解释了O和O_2(a~1Δ_g)可以实现助燃的原因。
Facing the problem of low efficiency of energy utilization in current energy crisis and the difficulty of stable combustion in the development of scramjet in aerospace dynamics, the combustion rate and efficiency need a higher requirement. According to these problems, this paper proposes a method of using femtosecond laser induced plasma to assist combustion. There exist plenty of free radicals, excited components in the plasma induced by femtosecond laser. And the existence of these active particles increases the rate of chian reactions of combustion and flame propagating, achieving the effect of assisting combustion.
The paper first analyzes the feasibility of combustion enhancement by femtosecond activation gas reactive molecules. Then we set up the combustion model using the flame propagation speed calculator module in CHEMKIN combined with methane burning mechanism with the action femtosecond laser. With this model, we analyze the influence of several active compents in plasma to the laminar pre-mixed flame. Using the methods of sentivity analysis and product generation rate analysis, we analyze the mechanism of combustion enhancement by O and O_2(a~1Δ_g) in laminar pre-mixed flame.
Through the simulation analysis, we found that O and O3 can improve flame propagation speed and concentrations of H, O, OH compenents through the whole range of equivalence, achiving the effect of combustion enhancement. CH_3 and CH_2 can improve flame propagation speed for poor fuel flame when the equivalent is lower than a certain boundry. Excited components O_2(a~1Δ_g) and O_2(b~1Σ_g~+) can obviously increase the flame propagation speed and concentrations of H, O, OH compents. The effects of combustion enhancement by O_2(b~1Σ_g~+) are more apparent than O_2(a~1Δ_g). We found that when acting with O_2, N_2(A~3Σ_u~+) can realize combustion enhancement by stimulating O_2 to O_2(a~1Δ_g) and O_2(b~1Σ_g~+) or disintegrate O_2 into O. At the same time, through disintegrating H2 into H, N_2(A~3Σ_u~+) can also realize combustion enhancement by increasing the concentration of H component in laminar pre-mixed flame.
Based on the mechanism analysis, we found that the reaction of H+O_2(?)O+OH is the most important one to control flame propagation speed and the concentration of H, O, OH in laminar pre-mixed flame. The existence of O and O_2(a~1Δ_g)in pre-mixed flame increase the forward reaction rate of the reactions with positive sensitivity to flame propagation speed and the reverse reaction rate of the reactions with negative sentivity to flame propagation speed. This phenomenon explains the reason of combustion enhancement by O and O_2(a~1Δ_g).
本文首先分析了激光激活气体反应分子助燃的可行性,在CHEMKIN软件中,利用层流预混火焰传播速度计算器模块并结合飞秒激光作用下的甲烷燃烧机理,建立起了飞秒激光激活气体反应分子的助燃模型。通过该模型分析了激光诱导等离子产生的几种活性组分对层流预混火焰的影响。最后通过敏感性分析并结合产物生成速率分析的方法对O和O_2(a~1Δ_g)的助燃机理进行了分析。
通过模拟分析发现,预混气体中O、O3的存在都可以在整个当量比的范围内提高火焰传播速度以及H、O、OH组分的浓度,实现助燃的效果。CH_3和CH_2只对当量比小于一定界限的贫燃料火焰才具有助燃作用。激发态组分O_2(a~1Δg)和O_2(b~1Σ_g~+)的存在都可以明显提高火焰传播速度和H、O、OH的浓度,但是O_2(a~1Δ_g)的助燃效果不如O_2(b~1Σ_g~+)明显。分析发现,N_2(A~3Σ_u~+)和O_2作用时可以将O_2激发为O_2(a~1Δ_g)、O_2(b~1Σ_g~+)或者解离为O,实现对层流预混火焰的助燃效果,同时N_2(A~3Σ_u~+)还可以和H2作用将其解离为H,通过提高预混气体中H的浓度而实现助燃。
通过对甲烷燃烧机理分析发现,H+O_2(?)O+OH这个反应是层流预混火焰中控制火焰传播速度和H、O、OH组分浓度的最重要的反应。预混气体中O和O_2(a~1Δ_g)的存在增加了火焰传播速度敏感性为正的反应的正向反应速率以及火焰传播速度敏感为负的反应的逆向反应速率,因此使得火焰传播速度得到提高,解释了O和O_2(a~1Δ_g)可以实现助燃的原因。
Facing the problem of low efficiency of energy utilization in current energy crisis and the difficulty of stable combustion in the development of scramjet in aerospace dynamics, the combustion rate and efficiency need a higher requirement. According to these problems, this paper proposes a method of using femtosecond laser induced plasma to assist combustion. There exist plenty of free radicals, excited components in the plasma induced by femtosecond laser. And the existence of these active particles increases the rate of chian reactions of combustion and flame propagating, achieving the effect of assisting combustion.
The paper first analyzes the feasibility of combustion enhancement by femtosecond activation gas reactive molecules. Then we set up the combustion model using the flame propagation speed calculator module in CHEMKIN combined with methane burning mechanism with the action femtosecond laser. With this model, we analyze the influence of several active compents in plasma to the laminar pre-mixed flame. Using the methods of sentivity analysis and product generation rate analysis, we analyze the mechanism of combustion enhancement by O and O_2(a~1Δ_g) in laminar pre-mixed flame.
Through the simulation analysis, we found that O and O3 can improve flame propagation speed and concentrations of H, O, OH compenents through the whole range of equivalence, achiving the effect of combustion enhancement. CH_3 and CH_2 can improve flame propagation speed for poor fuel flame when the equivalent is lower than a certain boundry. Excited components O_2(a~1Δ_g) and O_2(b~1Σ_g~+) can obviously increase the flame propagation speed and concentrations of H, O, OH compents. The effects of combustion enhancement by O_2(b~1Σ_g~+) are more apparent than O_2(a~1Δ_g). We found that when acting with O_2, N_2(A~3Σ_u~+) can realize combustion enhancement by stimulating O_2 to O_2(a~1Δ_g) and O_2(b~1Σ_g~+) or disintegrate O_2 into O. At the same time, through disintegrating H2 into H, N_2(A~3Σ_u~+) can also realize combustion enhancement by increasing the concentration of H component in laminar pre-mixed flame.
Based on the mechanism analysis, we found that the reaction of H+O_2(?)O+OH is the most important one to control flame propagation speed and the concentration of H, O, OH in laminar pre-mixed flame. The existence of O and O_2(a~1Δ_g)in pre-mixed flame increase the forward reaction rate of the reactions with positive sensitivity to flame propagation speed and the reverse reaction rate of the reactions with negative sentivity to flame propagation speed. This phenomenon explains the reason of combustion enhancement by O and O_2(a~1Δ_g).
引文
[1]司徒明.超燃冲压发动机的研究现状和动向.飞航导弹. 1996, (7): 24-34.
[2]刘小勇.超燃冲压发动机技术.飞航导弹. 2003, (2): 38-42.
[3]贺武生.超燃冲压发动机研究综述.火箭推进. 2005, 31(1): 29-32.
[4]邱朋华等.燃烧学.哈尔滨工业大学教学讲义. 8-10.
[5]郭向阳,何立明,兰宇丹,陈灯.基于化学平衡的等离子体助燃计算与分析.空军工程大学学报. 2007, 8(6): 8-11.
[6] S.A. Zhdanok. Nonequilibrium processes and their applications. Applied Thermal Engineering. 2008, 28: 254-260.
[7] I A Kossyi, AY Kostinsky, A A Matveyev and V P Silakov. Kinetic scheme of the non-equilibrium discharge in nitrogen-oxygen mixtures. Plasma Source Sci. Technol. 1992, 1: 207-220.
[8]任晓丽. 1万2千伏直流高压电场对火焰传播速度影响的研究.应用技术. 1993, 1: 59-65.
[9] C.Uykur, P.F.Henshaw, K.ting, et al. Effects of addition of electrolysis products on methane/air premixed laminar combustion. International Journal of Hydrogen Energy.2001, 26: 265-273.
[10] S.M.Starikovsaia, Starikovskii, Zhukov, et al. Control of combustion and ignition hydrocarbon-containing mixtures by nanosecond pulsed discharges. Aerospace Sciences Meeting and Exhibit. 2005-1195.
[11] A. M. Starik and N. S. Titova. Possibility of initiation of combusiton of CH_4-O_2(air) mixtures with laser-induced excitation of O_2 molecules. Combustion, Explosion and Shock Waves. 2004, 40(5): 499-510.
[12] Alexander M.Starik, et al. Initiation of combustion and detonation by laser induced electronical excitation of O_2 molecules to the a~1Δ_g and b~1Σ_g~- states. Proceedings of SPIE. 2002, 4760: 609-620.
[13]郭向阳,何立明,兰宇丹.非平衡性等离子体对燃烧影响的研究.弹箭与制导学报. 2008, 28(6): 148-151.
[14]杜洪亮,何立明,兰宇丹等.等离子体对氢气-空气混合物燃烧过程影响的数值研究.弹箭与指导学报. 2008, 28(6): 141-143.
[15]郭向阳,何立明,兰宇丹,陈灯.非平衡等离子体对甲烷燃烧影响的研究.弹箭与制导学报. 2008, 28(4): 155-157.
[16] A.Bourig, D. Thévenin, J.-P. Martinet al. Numerical modeling of H_2-O_2 flames involving electronically-excited species O_2(a~1Δ_g), O(1~D) and OH(2~Σ~+). Proceedings of the Combustion Institute. 2009, 32: 3171-3179.
[17] A.M.Starik, V.E.Kozlov, N.S.Titova. On the influence of singlet oxygen molecules on the speed of flame propagation in methane-air mixture. Combustion and Flame. 2010, 157: 313-327.
[18]丁伟,何立明,宋振兴.常压空气介质阻挡放电的能量传递过程.高电压技术. 2010, 36(3): 745-751.
[19] Timothy Ombrello, Sang Hee Won, Yiguang Ju, et al. Flame propagation enhancement by plasma excitation of oxygen. PartⅡ:Effects of O_2(a~1Δ_g). Combustion and Flame. 2010. 02. 004.
[20]杜洪亮,何立明,丁伟等.介质阻挡放电中氧原子的数值模拟.高压电器. 2010,,46(11):38-42.
[21]闫传俊.燃烧学.西北工业大学出版社. 2005: 2-4.
[22]张艳春.层流预混火焰传播特性概述.化工装备技术. 2003, 24(2): 56-60.
[23] D.P. Mishra. Effects of initial temperature on the structure of laminar CH_4-air premixed flames. Fuel. 2003, 82: 1471-1475.
[24]董刚,陈义良.低压CH_4/O_2/N_2预混火焰结构的数值预测.中国科学技术大学学报. 2000, 30(3): 329-333.
[25]许越.化学反应动力学.化学工业出版社. 2005: 52-53.
[26]张建成.现代光化学.化学工业出版社. 2006: 25-27.
[27]董刚,蒋勇,陈义良,王清安.大型气相化学动力学软件包CHEMKIN及其在燃烧中的应用.火灾科学. 2000, 9(1): 27-33.
[28] http://www.me.berkeley.edu/gri_mech/
[29]孔文俊. CH_4/O_2/N_2预混、层流、稳态火焰反应机理分析.燃烧科学与技术. 1998, 4(2): 168-176.
[30]曹德兆, D.W.Setser. N_2(A)的能量转移反应.量子电子学. 1986(4): 317-318.
[31] A.M.Starik, B.I.Lukhovitsky, N.S.Titova. Initiation of combustion by laser-induced excitation of molecular vibrations of reactants. Journal of Russian Laser Research. 2006, 27(6): 553-551.
[32] A.M.Starik, N.S.Titova. Initiation of combustion of a Methane-air mixture in a supersonic flow behind a shock wave during laser excitation of O_2 molecules. Technical Physics. 2004, 74(9): 1116-1125.
[33] Alexander M.Starik, Nataliya S.Titova. Initiation of combustion and detonation by laser induced electronical excitation of O_2 molecules to the a~1Δ_g and b~1Σ_g~+ states.Proceedings of SPIE. 2002(4760): 609-618.
[34] B.I.Lukhovitskii, A.M.Starik and N.S.Titova. Activation of chain processes in combustible mixtures by laser excitation of molecular vibrations of reactants. Combustion, Explosion, and Shock Waves. 2005, 41(4): 386-394.
[35]邵强.激光激活氧分子助燃CH_4/O_2预混燃烧理论与实验研究.哈尔滨工业大学硕士学位论文. 2008: 23-25.
[36] Levron, D., Phelps, A.V. Quenching of N_2(A~3Σ_u~+,v=0,1) by N_2, Ar and H_2. Journal of Chemical Physics. 1978, 69 (5), 2260-2262.
[37] Anders Broe Bendtsen, Peter Glarborg,Kim Dam-Johansen. Visualization methods in analysis of detailed chemical kinetics modeling. Computers and Chemistry. 2001(25): 161-170.
[38]Tamas Turanyi. Sensitivity analysis of complex kinetics systems tools and applications. Journal of Mathematical Chemistry. 1990(5): 203-248.
[39] Alison.S.Tomlin. The use of global uncertainty methods for the evaluation of combustion mechanism. Reliability Engineering and System Safety. 2006(91): 1219-1231.
[40] Valerie Leroy, Eric Leoni and Paul-Antoine santoni. Reduced mechanism for the combustion of evolved gases in forest fires. Combustion and Flame. 2008(154): 410-433.
[41]乔瑜,徐明厚,姚洪.基于敏感性分析的甲烷反应机理优化简化.华中科技大学学报. 2007, 35(5): 85-87.
[42] Alison. S.Tomlin. The use of global uncertainty methods for the evaluatin of combustion mechanisms. Reliability Engineering and System Safety. 2006,91: 1219-1231.
[43] Tamas Turanyi. Applications of sensitivity analysis to combustion chemistry. Reliability Engineering and System Safety. 1997(57): 41-48.
[44] R. J. Kee, F. M. Rupley, J. A. Miller, M. E. Coltrin, J. F. Grcar, E. Meeks, H. K. Moffat, A. E. Lutz, G. Dixon-Lewis, M. D. Smooke, J. Warnatz, G. H. Evans, R. S. Larson, R. E. Mitchell, L. R. Petzold, W. C. Reynolds, M. Caracotsios, W. E. Stewart, P. Glarborg, C. Wang, O. Adigun, W. G. Houf, C. P. Chou, S. F. Miller, P. Ho, and D. J. Young. CHEMKIN Release 4.1 Theory Manual, Reaction Design, Inc, San Diego, CA (2006).
[2]刘小勇.超燃冲压发动机技术.飞航导弹. 2003, (2): 38-42.
[3]贺武生.超燃冲压发动机研究综述.火箭推进. 2005, 31(1): 29-32.
[4]邱朋华等.燃烧学.哈尔滨工业大学教学讲义. 8-10.
[5]郭向阳,何立明,兰宇丹,陈灯.基于化学平衡的等离子体助燃计算与分析.空军工程大学学报. 2007, 8(6): 8-11.
[6] S.A. Zhdanok. Nonequilibrium processes and their applications. Applied Thermal Engineering. 2008, 28: 254-260.
[7] I A Kossyi, AY Kostinsky, A A Matveyev and V P Silakov. Kinetic scheme of the non-equilibrium discharge in nitrogen-oxygen mixtures. Plasma Source Sci. Technol. 1992, 1: 207-220.
[8]任晓丽. 1万2千伏直流高压电场对火焰传播速度影响的研究.应用技术. 1993, 1: 59-65.
[9] C.Uykur, P.F.Henshaw, K.ting, et al. Effects of addition of electrolysis products on methane/air premixed laminar combustion. International Journal of Hydrogen Energy.2001, 26: 265-273.
[10] S.M.Starikovsaia, Starikovskii, Zhukov, et al. Control of combustion and ignition hydrocarbon-containing mixtures by nanosecond pulsed discharges. Aerospace Sciences Meeting and Exhibit. 2005-1195.
[11] A. M. Starik and N. S. Titova. Possibility of initiation of combusiton of CH_4-O_2(air) mixtures with laser-induced excitation of O_2 molecules. Combustion, Explosion and Shock Waves. 2004, 40(5): 499-510.
[12] Alexander M.Starik, et al. Initiation of combustion and detonation by laser induced electronical excitation of O_2 molecules to the a~1Δ_g and b~1Σ_g~- states. Proceedings of SPIE. 2002, 4760: 609-620.
[13]郭向阳,何立明,兰宇丹.非平衡性等离子体对燃烧影响的研究.弹箭与制导学报. 2008, 28(6): 148-151.
[14]杜洪亮,何立明,兰宇丹等.等离子体对氢气-空气混合物燃烧过程影响的数值研究.弹箭与指导学报. 2008, 28(6): 141-143.
[15]郭向阳,何立明,兰宇丹,陈灯.非平衡等离子体对甲烷燃烧影响的研究.弹箭与制导学报. 2008, 28(4): 155-157.
[16] A.Bourig, D. Thévenin, J.-P. Martinet al. Numerical modeling of H_2-O_2 flames involving electronically-excited species O_2(a~1Δ_g), O(1~D) and OH(2~Σ~+). Proceedings of the Combustion Institute. 2009, 32: 3171-3179.
[17] A.M.Starik, V.E.Kozlov, N.S.Titova. On the influence of singlet oxygen molecules on the speed of flame propagation in methane-air mixture. Combustion and Flame. 2010, 157: 313-327.
[18]丁伟,何立明,宋振兴.常压空气介质阻挡放电的能量传递过程.高电压技术. 2010, 36(3): 745-751.
[19] Timothy Ombrello, Sang Hee Won, Yiguang Ju, et al. Flame propagation enhancement by plasma excitation of oxygen. PartⅡ:Effects of O_2(a~1Δ_g). Combustion and Flame. 2010. 02. 004.
[20]杜洪亮,何立明,丁伟等.介质阻挡放电中氧原子的数值模拟.高压电器. 2010,,46(11):38-42.
[21]闫传俊.燃烧学.西北工业大学出版社. 2005: 2-4.
[22]张艳春.层流预混火焰传播特性概述.化工装备技术. 2003, 24(2): 56-60.
[23] D.P. Mishra. Effects of initial temperature on the structure of laminar CH_4-air premixed flames. Fuel. 2003, 82: 1471-1475.
[24]董刚,陈义良.低压CH_4/O_2/N_2预混火焰结构的数值预测.中国科学技术大学学报. 2000, 30(3): 329-333.
[25]许越.化学反应动力学.化学工业出版社. 2005: 52-53.
[26]张建成.现代光化学.化学工业出版社. 2006: 25-27.
[27]董刚,蒋勇,陈义良,王清安.大型气相化学动力学软件包CHEMKIN及其在燃烧中的应用.火灾科学. 2000, 9(1): 27-33.
[28] http://www.me.berkeley.edu/gri_mech/
[29]孔文俊. CH_4/O_2/N_2预混、层流、稳态火焰反应机理分析.燃烧科学与技术. 1998, 4(2): 168-176.
[30]曹德兆, D.W.Setser. N_2(A)的能量转移反应.量子电子学. 1986(4): 317-318.
[31] A.M.Starik, B.I.Lukhovitsky, N.S.Titova. Initiation of combustion by laser-induced excitation of molecular vibrations of reactants. Journal of Russian Laser Research. 2006, 27(6): 553-551.
[32] A.M.Starik, N.S.Titova. Initiation of combustion of a Methane-air mixture in a supersonic flow behind a shock wave during laser excitation of O_2 molecules. Technical Physics. 2004, 74(9): 1116-1125.
[33] Alexander M.Starik, Nataliya S.Titova. Initiation of combustion and detonation by laser induced electronical excitation of O_2 molecules to the a~1Δ_g and b~1Σ_g~+ states.Proceedings of SPIE. 2002(4760): 609-618.
[34] B.I.Lukhovitskii, A.M.Starik and N.S.Titova. Activation of chain processes in combustible mixtures by laser excitation of molecular vibrations of reactants. Combustion, Explosion, and Shock Waves. 2005, 41(4): 386-394.
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