氢能由于燃烧产物清洁、能量利用率高近年来备受欢迎，然而氢能输运成本高、能量密度低、燃烧速度过快的缺陷限制了氢能的推广使用，而氨能资源丰富、易于输送，和氢气掺混形成的氨-氢混合气体结合了两者的优点，为解决能源紧缺和环境污染问题提供了新方向。氨气掺氢在提高燃烧性能的同时也增加了燃烧爆炸的风险，因此，开展氨-氢混合气体的抑爆研究对氨-氢混合燃料的输运和使用安全具有重要意义。 本文在石英玻璃管道中测定了不同CO2体积分数及不同掺氢比例的氨-氢混合气体爆炸极限，利用高速相机拍摄火焰传播过程，明确贫燃条件下CO2对不同掺氢比例、不同当量比的氨-氢混合气体火焰形态、火焰传播速度及火焰前锋位置的影响规律，并运用CHEMKIN动力学软件分析CO2对氨-氢混合气体爆炸动力学反应参数及关键反应步敏感性的影响规律。 研究结果表明，在氨气中掺氢拓宽了氨气的爆炸上下限，随着掺氢比例的增加，氨-氢混合气体爆炸极限范围扩大，爆炸危险性升高，火焰亮度增加，火焰横截面逐渐变宽，直至充满管道横截面，同时平均火焰传播速度增加，传播至封闭端所需时间显著缩短。贫燃条件下，随着当量比的增加，火焰横截面逐渐变宽，火焰火焰传播速度增加。在掺氢比例和当量比的共同作用下，氨-氢混合气体火焰传播速度加快，速度增加到一定值时，随着火焰传播，斜坡型火焰前锋逐渐褶皱，形成褶皱的斜坡型火焰，最后形成平面型火焰和郁金香型火焰，并呈现出“出现-消失-再现”特征的火焰震荡周期。随着掺氢比例和当量比的增加，郁金香型火焰传播速度震荡幅度逐渐增大，开始大幅度震荡时间提前。添加CO2可以有效降低火焰平均传播速度，增加火焰到达封闭端时间，同时CO2也可有效抑制郁金香火焰的形成，使火焰震荡幅度减弱，火焰传播速度峰值降低，火焰从开口端到达封闭端传播时长显著增加。且随着掺氢比例和当量比的增加，需要更多的体积分数的CO2才能抑制氨-氢混合气体的燃烧。 通过CHEMKIN仿真计算结果可知，随着掺氢比例和当量比的增加，层流燃烧速度增加，绝热火焰温度也逐渐升高，添加CO2可以有效降低层流燃烧速度和绝热火焰温度。随着掺氢比例和当量比的增加，H·、NH2·等活性基团的摩尔分数升高，促进了基元反应的反应速率，从而提高了火焰层流燃烧速度。CO2的添加显著降低了H·、O·、OH·、NH2·等活性基团的摩尔分数和净反应速率，进而抑制燃烧反应进程，使火焰层流燃烧速度降低。

Hydrogen energy has been popular in recent years due to its clean combustion products and high energy utilization rate. But the defects of high hydrogen energy transportation cost, low energy density and fast combustion speed limit the promotion and use of hydrogen energy. Ammonia energy is rich in resources and easy to transport. The ammonia-hydrogen mixed gas formed by mixing hydrogen combines the advantages of both, providing a new direction for solving problems of energy shortage and environmental pollution. Hydrogen - doped ammonia can improve the combustion performance and increase the risk of combustion and explosion. Therefore, it is of great significance to study the explosion suppression of ammonia-hydrogen mixed gas for the transportation and safety of ammonia-hydrogen mixed fuel.

In this paper, the explosion limits of ammonia-hydrogen mixed gas with different CO₂ volume fractions and different hydrogen blending ratios were measured in quartz glass pipes. The flame propagation process was captured by a high-speed camera to clarify the influence of CO₂ on the flame shape, flame propagation speed and flame front position of ammonia - hydrogen mixed gas with different hydrogen blending ratios and different equivalence ratios. The CHEMKIN kinetic software was used to analyze the sensitivity of CO₂ to the kinetic reaction parameters and key reaction steps of ammonia - hydrogen mixed gas explosion.

The results show that the addition of hydrogen in ammonia broadens the upper and lower explosion limits of ammonia. With the increase of hydrogen ratio, the explosion limit range of ammonia - hydrogen mixed gas expands, the explosion risk increases, the flame brightness increases, and the flame cross section gradually widens until it fills the pipe truss surface. At the same time, the average flame propagation speed increases, and the time required to propagate to the closed end is significantly shortened. Under lean combustion conditions, as the equivalence ratio increases, the flame cross section gradually widens and the flame propagation speed increases. Under the combined action of hydrogen blending ratio and equivalence ratio, the flame propagation speed of ammonia-hydrogen mixed gas increases. When the speed increases to a certain value, as the flame propagates, the slope flame front gradually folds to form a folded slope flame, and finally forms a flat flame and a tulip flame, and presents a flame shock with the characteristics of 'appearance - disappearance - reappearance '.With the increase of hydrogen blending ratio and equivalence ratio, the oscillation amplitude of tulip flame propagation velocity gradually increases, and the start time of large amplitude oscillation is advanced. The addition of CO₂ can effectively reduce the average flame propagation speed and increase the time of flame reaching the closed tube. At the same time, CO₂ can also effectively inhibit the formation of tulip flame, weaken the flame oscillation amplitude, reduce the peak value of flame propagation speed, and increase the flame propagation time from the opening end to the closed end. With the increase of hydrogen ratio and equivalence ratio, more volume fraction of CO₂ is needed to suppress combustion.

The results of CHEMKIN simulation show that with the increase of hydrogen blending ratio and equivalence ratio, the laminar burning velocity increases, and the adiabatic flame temperature also increases gradually. Adding CO₂ can effectively reduce the laminar burning velocity and adiabatic flame temperature. With the increase of hydrogen doping ratio and equivalence ratio, the mole fraction of active groups such as H· group and NH₂· group increases, which promotes the reaction rate of elementary reaction and improves the laminar burning velocity of flame. The addition of CO₂ significantly reduced the molar fraction and net reaction rate of active groups such as H·, O·, OH· and NH₂ groups, thereby inhibiting the combustion reaction process and reducing the laminar flame combustion rate.

[1] 苏洋. 氢气/甲烷/空气预混气体爆燃特性及抑制规律研究[D]. 焦作：河南理工大学, 2018.

[2] 何建坤. 中国能源革命与低碳发展的战略选择[J]. 武汉大学学报(哲学社会科学版), 2015, 68(01): 5-12.

[3] 马涛, 孙佰清, 郭海凤, 等. 我国中长期经济发展中氢能消费量及CO2 减排效果估算[J]. 太阳能学报, 2010, 31(11): 1521-1526.

[4] 赵永志, 蒙波, 陈霖新, 等. 氢能源的利用现状分析[J]. 化工进展, 2015, 34(09): 3248-3254.

[5] 蔡立柱, 王靖雯, 李涵. 浅谈氢能源技术优势及发展[J]. 中国新技术新产品, 2015, (3): 175.

[6] 赵永志, 蒙波, 陈霖新, 等. 氢能源的利用现状分析[J]. 化工进展, 2015, 34(9): 3248-3255.

[7] 李强. 进气歧管喷射式氢气发动机性能研究[D]. 武汉: 武汉理工大学, 2008.

[8] 郭朋彦, 刘子川, 邵方阁, 等. 氢氨清洁无污染无碳燃料在发动机上的应用分析[J]. 汽车实用技术, 2016 (4): 81-84.

[9] 朱雨涵, 程斌, 张丰, 等. 氨气/丙烷混合燃烧及NOx生成特性研究[C]. 第十一届全国能源与热工学术年会论文集. 马鞍山： 中国金属学会能源与热工分会, 2021: 492-498.

[10] 周上坤, 杨文俊, 崔保崇, 等. 氨燃烧污染物特性的实验研究及动力学分析[J].华中科技大学学报(自然科学版), 2022, 50(07): 121-129.

[11] Chiuta S, Everson R C, Neomagus H, et al. Reactor technology options for distributed hydrogen generation via ammonia decomposition: A review[J]. International Journal of Hydrogen Energy, 2013, 38(35): 14968-14991.

[12] 唐广. 氨-氢混合无碳燃料预混火焰燃烧特性研究[D]. 哈尔滨: 哈尔滨工业大学, 2021.

[13] Hayakawa A, Goto T, Mimoto R, et al. Laminar burning velocity and Markstein length of ammonia/air premixed flames at various pressures[J]. Fuel, 2015, 159(1): 98-106.

[14] Han X, Wang Z, He Y, et al. The temperature dependence of the laminar burning velocity and superadiabatic flame temperature phenomenon for NH3 / air flames[J]. Combustion and Flame, 2020, 217: 314-320.

[15] Li Y, Bi M, Li B, et al. Explosion behaviors of ammonia-air mixtures[J]. Combustion Science and Technology, 2018, 190(10): 1-13.

[16] Duynslaegher C, Jeanmart H, Vandooren J, et al. Ammonia combustion at elevated pressure and temperature conditions[J]. Fuel, 2010, 89(11): 3540-3545.

[17] Rocha R, Costa M, Bai X S, et al. Chemical kinetic modelling of ammonia / hydrogen / air ignition, premixed flame propagation and NO emission[J]. Fuel, 2019, 246: 24-33.

[18] Osamu K, Norihiko I, Takahiro I, et al. Development of a wide range-operable, rich-lean low-NOx combustor for NH3 fuel gas-turbine power generation[J]. Proceedings of the Combustion Institute, 2019, 37(4): 4587-4595.

[19] Duynslaegher C, Jeanmart H, andooren J, et al. Flame structure studies of premixed ammonia / hydrogen / oxygen /argon flames: Experimental and numerical investigation [J]. Proceedings of the Combustion Institute, 2009, 32(1): 1277-1284.

[20] Schoor F, Norman F, andebroek L, et al. A numerical study of the influence of ammonia addition on the auto-ignition limits of methane / air mixtures[J]. Journal of hazardous materials, 2008, 164(2-3): 1164-1170.

[21] Comotti M, Frigo S. Hydrogen generation system for ammonia-hydrogen fuelled internal combustion engines[J]. International Journal of Hydrogen Energy, 2015, 40(33): 10673-10686.

[22] Valera M A, Pugh D G, Marsh P, et al. Preliminary study on lean premixed combustion of ammonia-hydrogen for swirling gas turbine combustors[J]. International Journal of Hydrogen Energy, 2017, 42(38): 24495-24503.

[23] Lhuillier C, Brequigny P, Contino F, et al. Experimental study on ammonia / hydrogen / air combustion in spark ignition engine conditions[J]. Fuel, 2020, 269: 117448.

[24] 郑凯. 管道中氢气/甲烷混合燃料爆燃预混火焰传播特征研究[D]. 重庆: 重庆大学, 2017.

[25] 张启波, 贾颖, 闫晓静. 石油甲烷长输管道危险性分析[J]. 中国安全科学学报, 2008, 18(7): 134-138.

[26] 冯文, 王淑娟, 倪维斗, 等. 氢能的安全性和燃料电池汽车的氢安全问题[J]. 太阳能学报, 2003, 24(5): 677-682.

[27] Lhuillier C, Brequigny P, Lamoureux N, et al. Experimental investigation on laminar burning velocities of ammonia / hydrogen / air mixtures at elevated temperatures[J]. Fuel, 2019, 263: 116653-116663.

[28] Lee S, Kwon O C. Effects of ammonia substitution on extinction limits and structure of counterflow nonpremixed hydrogen/air flames[J]. International Journal of Hydrogen Energy, 2011, 36(16): 10117 -10128.

[29] Lee J H, Kim J H, Park J H, et al. Studies on properties of laminar premixed hydrogen - added ammonia / air flames for hydrogen production[J]. International Journal of Hydrogen Energy, 2010, 35(3): 1054-1064.

[30] Lee J H, Lee S I, Kwon O C, et al. Effects of ammonia substitution on hydrogen / air flame propagation and emissions[J]. International Journal of Hydrogen Energy, 2010, 35(20): 11332-11341.

[31] Choi S, Lee S, Kwon O C, et al. Extinction limits and structure of counter flow nonpremixed hydrogen-doped ammonia / air flames at elevated temperatures[J]. Energy, 2015, 85(6.1):503-510.

[32] Li Y, Bi M, Zhou Y, et al. Characteristics of hydrogen-ammonia-air cloud explosion[J]. Process Safety and Environmental Protection, 2021, 148: 1207-1216.

[33] Liu Y, Han D. Numerical study on explosion limits of ammonia / hydrogen / oxygen mixtures: Sensitivity and eigenvalue analysis[J]. Fuel, 2021, 300(15): 120964.1- 120964.6.

[34] 周永浩, 张宗岭, 胡思彪, 等. NH3/H2预混旋流火焰稳定性及燃烧极限实验研究[J]. 工程热物理学报, 2021, 42(1): 246-253.

[35] Han X, Wang Z, Costa M, et al. Experimental and kinetic modeling study of laminar burning velocities of NH3 / air, NH3 / H2 / air, NH3 / CO / air and NH3 / CH4 / air premixed flames[J]. Combustion and Flame, 2019, 206: 214-226.

[36] Ichikawa A, Hayakawa A, Kitagawa Y, et al. Laminar burning velocity and Markstein length of ammonia / hydrogen /air premixed flames at elevated pressures[J]. International Journal of Hydrogen Energy, 2015, 40(30): 9570-9578.

[37] Yan C, Bi M , Li Y , et al. Effects of nitrogen and carbon dioxide on hydrogen explosion behaviors near suppression limit[J]. Journal of Loss Prevention in the Process Industries, 2020, 67(2): 104228-104238.

[38] 张迎新, 吴强, 刘传海，等. 惰性气体N2 / CO2 抑制瓦斯爆炸实验研究[J]. 爆炸与冲击, 2017, 37(5): 906-912.

[39] 王华, 葛岭梅, 邓军. 惰性气体抑制矿井瓦斯爆炸的实验研究[J]. 矿业安全与保, 2008, 35(1): 4-7.

[40] 余明高, 韦贝贝, 郑凯. N2与CO2对合成气爆炸特性影响的实验研究[J]. 爆炸与冲击, 2019, 39(6) :155-162.

[41] 张迎新, 吴强, 刘传海, 等. 惰性气体N2 / CO2抑制瓦斯爆炸实验研究[J]. 爆炸与冲击, 2017, 037(005): 906-912.

[42] 罗振敏, 康凯. CO2抑制甲烷-空气链式爆炸微观机理的仿真分析[J]. 中国安全科学学报, 2015, 25(5): 42-48.

[43] 陆卫东, 贾宝山, 李守国，等. CO2气体对瓦斯爆炸的阻尼效应研究[J]. 煤矿安全, 2016, 47(9): 1-3.

[44]Yang X, Song F, Wu Y, et al. Investigation of rotating detonation fueled by a methane - hydrogen - carbon dioxide mixture under lean fuel conditions[J]. International Journal of Hydrogen Energy, 2020, 45(41): 21995-22007.

[45] Cui S, Shao H, Jiang S, et al. Experimental study on gas explosion suppression by coupling CO2 to a vacuum chamber[J]. Powder Technology, 2018, 335: 42-53.

[46] 陈晓坤, 丁园月, 程方明,等. CO2对矿井多组分可燃性气体抑爆特性的影响[J]. 煤炭科学技术, 2015(3): 43-47.

[47] 黄潜, 苗海燕, 黄佐华,等. EGR 中二氧化碳对氢气层流燃烧特性的影响[J]. 燃烧科学与技术, 2009, 15(4): 361-367.

[48] 李润之. CO2与C3F7H抑制CH4爆炸对比实验研究[J]. 煤矿安全, 2016, 47(10): 25-28.

[49] 冯翼鲲, 曹雄, 曹卫国,等. 方形管道中二氧化碳抑爆性能实验研究[J]. 消防科学与技术, 2018, 37(1): 14-18.

[50] Miller J A, Smooke M D, Green R M, et al. Kinetic Modeling of the Oxidation of Ammonia in Flames[J].Combustion Science&Technology, 1983, 34(1-6): 149-176.

[51] Duynslaegher C, Contino F, Vandooren J, et al. Modeling of ammonia combustion at low pressure[J]. Combustion and Flame, 2012, 159(9): 2799–2805.

[52] Konnov A A. Implementation of the NCN pathway of prompt-NO formation in the detailed reaction mechanism[J]. Combust ion and Flame, 2009, 156(11): 2093–2105.

[53] Xiao H, Howard M, Valera M A, et al. Study on reduced chemical mechanisms of ammonia / methane combustion under gas turbine conditions[J]. Energy Fuels, 2016, 30(10): 8701–8710.

[54] Song Y, Hashemi H, Christensen J M, et al. Ammonia oxidation at high pressure and intermediate temperatures[J]. Fuel, 2016, 181: 358–365.

[55] Klippenstein S J, Harding L B, Glarborg P, et al. The role of NNH in NO formation and control[J]. Combust Flame, 2011, 158(4): 774–789.

[56] Mathieu O, Petersen E L. Experimental and modeling study on the high-temperature oxidation of ammonia and related NOx chemistry[J]. Combust Flame, 2015, 162(3): 554–570.

[57] Xiao H, Valera M A, Bowen P J, et al. Modeling combustion of ammonia / hydrogen fuel blends under gas turbine conditions[J]. Energy Fuels, 2017, 31(8): 8631–8642.

[58] Otomo J, Koshi M, Mitsumori T, et al. Chemical kinetic modeling of ammonia oxidation with improved reaction mechanism for ammonia / air and ammonia / hydrogen / air combustion[J]. Int J Hydrogen Energy, 2018, 43(5): 3004–3014.

[59] Okafor E C, Naito Y, Colson S, et al. Measurement and modelling of the laminar burning velocity of methane-ammonia air flames at high pressures using a reduced reaction mechanism[J]. Combust Flame, 2019, 204: 162–175.

[60] http://combustion.berkeley.edu/gri-mech/version30/text30.html.

[61] Tian Z, Li Y, Zhang L, et al. An experimental and kinetic modeling study of premixed NH3/CH4/O2/Ar flames at low pressure[J]. Combust Flame, 2009, 156(7): 1413–1426.

[62] Li R, Konnov A A, He G, et al. Chemical mechanism development and reduction for combustion of NH3/ H2/ CH4 mixtures[J]. Fuel, 2019, 257: 116059.1-116059.13.

[63] Shrestha K P, Seidel L, Zeuch T, et al. Detailed kinetic mechanism for the oxidation of ammonia including the formation and reduction of nitrogen oxides[J]. Energy Fuels, 2018; 32(10): 10202–10217.

[64] Rodolfo C, Mário C, Bai X S, et al. Chemical kinetic modelling of ammonia/ hydrogen/ air ignition premixed flame propagation and NO emission[J]. Fuel, 2019, 246: 24-33.

[65] Han X, Wang Z, He Y, et al. Experimental and kinetic modeling study of laminar burning velocities of NH3/syngas/air premixed flames[J]. Combustion and Flame, 2020, 213:1-13.

[66] Mei B, Zhang X, Ma S, et al. Experimental and kinetic modeling investigation on the laminar flame propagation of ammonia under oxygen enrichment and elevated pressure conditions[J]. Combustion and Flame, 2019, 210(12): 236-246.

[67] Clanet C, Searby G. On the “tulip flame” phenomenon[J]. Combustion and Flame, 1996, 105(1.2): 226-238.

[68] 陈晓坤, 马赛燕, 程方明, 等. 封闭管道内CO2对掺氢甲烷燃爆特性的影响[J/OL]. 安全与环境学报: 1-9[2023-02-25].DOI:10.13637/j.issn.1009-6094.2022.2087.

[69] Han X, Wang Z, Costa M, et al. Experimental and kinetic modeling study of laminar burning velocities of NH3 / air, NH3 / H2 / air, NH3/CO/air and NH3 / CH4 / air premixed flames[J]. Combustion and Flame, 2019, 206: 214-226.

[70] Li J, Huang H, Kobayashi N, et al. Study on using hydrogen and ammonia as fuels: Combustion characteristics and NOx formation[J]. International Journal of Energy Research, 2014, 38(9): 1214-1223.

[71] 李艳超. 氢气火焰失稳传播与爆炸压力的耦合影响机制研究[D]. 大连理工大学, 2019.