O2/CO2氛围下正庚烷的燃烧机理研究

doi:10.11949/0438-1157.20230018

化工学报 ›› 2023, Vol. 74 ›› Issue (5): 2157-2169.DOI: 10.11949/0438-1157.20230018

O₂/CO₂氛围下正庚烷的燃烧机理研究

李晨曦¹(), 刘永峰¹(), 张璐¹, 刘海峰², 宋金瓯², 何旭³

^1.北京建筑大学北京市建筑安全监测工程技术研究中心，北京 102627
^2.天津大学内燃机燃烧学国家重点实验室，天津 300072
^3.北京理工大学机械与车辆学院，北京 100081

收稿日期:2023-01-09 修回日期:2023-05-05 出版日期:2023-05-05 发布日期:2023-06-29
通讯作者: 刘永峰
作者简介:李晨曦（1998—），男，硕士研究生，864173413@qq.com
基金资助:
国家自然科学基金项目(51976007);内燃机燃烧学国家重点实验室开放研究项目(K2023-04);北京建筑大学研究生创新项目(PG2022129)

Quantum chemical analysis of n-heptane combustion mechanism under O₂/CO₂ atmosphere

Chenxi LI¹(), Yongfeng LIU¹(), Lu ZHANG¹, Haifeng LIU², Jin’ou SONG², Xu HE³

^1.Beijing Engineering Research Center of Monitoring for Construction Safety, Beijing University of Civil Engineering and Architecture, Beijing 102627, China
^2.State Key Laboratory of Engines, Tianjin University, Tianjin 300072, China
^3.School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, China

Received:2023-01-09 Revised:2023-05-05 Online:2023-05-05 Published:2023-06-29
Contact: Yongfeng LIU

摘要/Abstract

摘要：

为研究正庚烷(n-C₇H₁₆)在O₂/CO₂氛围下的燃烧特性，提出了基于CO₂与H·详细反应路径的C-H燃烧机理。通过密度泛函理论对CO₂与H·可能存在的反应路径进行了分析，根据定容燃烧弹实际尺寸建立了计算网格，利用C-H机理计算了正庚烷在不同氛围(空气、53%O₂/47%CO₂、61%O₂/39%CO₂)下的燃烧过程；搭建了定容燃烧弹可视化实验平台，对正庚烷在不同氛围下的燃烧过程进行了测量；对CO₂的反应位点、CO₂+H· $→$ CO+·OH的反应能垒、火焰长度进行了分析。结果表明：C-H机理可以很好地预测正庚烷在O₂/CO₂氛围下的燃烧火焰长度，在50%O₂/50%CO₂氛围下的最大误差和平均误差分别为9.60%、2.42%；反应位点分析发现，CO₂氧原子的反应活性大于碳原子，氧端的平均局部离子化能和分子表面静电势分别为297.72 kcal/mol、-13.08 kcal/mol；H·与CO₂的碳原子和氧原子均可发生结合，反应能垒分别为26.71、11.07 kcal/mol。

关键词: 二氧化碳, 计算化学, 计算流体力学, 定容燃烧弹, 反应位点, 火焰长度

Abstract:

In order to study the combustion characteristics of n-heptane under O₂/CO₂atmosphere, a C-H combustion mechanism based on the detailed reaction paths of CO₂ and H· was proposed. The possible reaction paths of CO₂ and H· were analyzed by using density functional theory, and the calculation grids were established according to the actual size of constant volume combustion chamber. The combustion processes of n-heptane under different atmospheres (air, 53%O₂/47%CO₂, 61%O₂/39%CO₂) were calculated through C-H mechanism. A constant volume incendiary bomb visualization experiment platform was built to measure the combustion process of n-heptane in different atmospheres. The reaction site of CO₂, the reaction energy barrier of CO₂+H· $→$ CO+·OH, and the flame length were analyzed. The results show that the C-H mechanism can well predict the combustion flame length of n-heptane under O₂/CO₂ atmosphere, and the maximum error and the average error are 9.60% and 2.42% respectively under 50%O₂/50%CO₂. The reactivity of oxygen atom of CO₂ is higher than that of carbon atom, and the average local ionization energy and molecular surface electrostatic potential at the oxygen ends are 297.72 and -13.08 kcal/mol, respectively. H· can combine with carbon atom and oxygen atom of CO₂, the reaction energy barrier are 26.71 and 11.07 kcal/mol, respectively.

Key words: carbon dioxide, computational chemistry, computational fluid dynamics, constant volume combustion chamber, reaction site, flame length

中图分类号:

TK 421

李晨曦, 刘永峰, 张璐, 刘海峰, 宋金瓯, 何旭. O₂/CO₂氛围下正庚烷的燃烧机理研究[J]. 化工学报, 2023, 74(5): 2157-2169.

Chenxi LI, Yongfeng LIU, Lu ZHANG, Haifeng LIU, Jin’ou SONG, Xu HE. Quantum chemical analysis of n-heptane combustion mechanism under O₂/CO₂ atmosphere[J]. CIESC Journal, 2023, 74(5): 2157-2169.

图/表 14

图1 CO2与H·的两条反应路径

Fig.1 Two chemical reaction paths of CO2 and H·

图2 机理简化流程

Fig.2 Mechanism simplification flow chart

图3 定容燃烧弹模型

Fig.3 Model of constant volume combustion chamber

图4 实验平台

Fig.4 Experimental platform

表1 实验参数

Table 1 Experimental parameters

参数	数值
喷射脉宽/ms	2
单次喷射质量/mg	18.4
喷射压力/MPa	120
预热温度间隔/K	60
燃料加压间隔/MPa	6
燃烧室初始温度/K	850
燃烧室初始压力/MPa	3
初始喷油压力/MPa	35
燃油温度/K	298
摄像机帧数/(帧/秒)	10000

图5 正庚烷燃烧过程与火焰温度云图

Fig.5 Combustion process and temperature cloud diagrams of n-heptane

图6 火焰长度

Fig.6 Combustion flame length

图7 实验与计算火焰长度

Fig.7 Comparison of experimental and computational CFL

图8 CO2平均局部离子化能和表面静电势

Fig.8 Average local ionization energy and electrostatic potential of CO2

图9 乙烯平均局部离子化能和表面静电势

Fig.9 Average local ionization energy and electrostatic potential of C2H4

图10 甲烷平均局部离子化能和分子表面静电势

Fig.10 Average local ionization energy and electrostatic potential of CH4

图11 CO2+H·→CO+·OH反应能垒

Fig.11 Reaction energy barrier of CO2+H·→CO+·OH

图12 温度敏感性分析

Fig.12 Temperature sensitivity analysis

表2 对温度最敏感的基元反应

Table 2 The most temperature sensitive elementary reaction

编号	反应
R14	H₂O₂+O₂ $→$ 2HO₂
R15	H₂O₂+H· $→$ H₂O+OH
R16	H₂O₂(+M) $→$ 2·OH(+M)
R823	C₇H₁₅O_2-2 $→$ C₇H_14-2+HO₂
R825	C₇H₁₅O_2-3 $→$ C₇H_14-3+HO₂
R826	C₇H₁₅O_2-4 $→$ C₇H_14-3+HO₂
R828	C₇H₁₅O_2-1 $→$ C₇H₁₄OOH_1-3
R1033	C₇H₁₅O_2-2 $→$ C₇H₁₄OOH_2-4
R1047	C₇H₁₅O_2-3 $→$ C₇H₁₄OOH_3-5
R1058	C₇H₁₅O_2-4 $→$ C₇H₁₄OOH_4-2
R1134	C₇H₁₄OOH_1-3O₂ $→$ nC₇KET13+OH
R1247	C₇H₁₄OOH_2-4O₂ $→$ nC₇KET24+OH
R1250	C₇H₁₄OOH_3-5O₂ $→$ nC₇KET35+OH

表2 对温度最敏感的基元反应

Table 2 The most temperature sensitive elementary reaction

编号	反应
R14	H₂O₂+O₂ $→$ 2HO₂
R15	H₂O₂+H· $→$ H₂O+OH
R16	H₂O₂(+M) $→$ 2·OH(+M)
R823	C₇H₁₅O_2-2 $→$ C₇H_14-2+HO₂
R825	C₇H₁₅O_2-3 $→$ C₇H_14-3+HO₂
R826	C₇H₁₅O_2-4 $→$ C₇H_14-3+HO₂
R828	C₇H₁₅O_2-1 $→$ C₇H₁₄OOH_1-3
R1033	C₇H₁₅O_2-2 $→$ C₇H₁₄OOH_2-4
R1047	C₇H₁₅O_2-3 $→$ C₇H₁₄OOH_3-5
R1058	C₇H₁₅O_2-4 $→$ C₇H₁₄OOH_4-2
R1134	C₇H₁₄OOH_1-3O₂ $→$ nC₇KET13+OH
R1247	C₇H₁₄OOH_2-4O₂ $→$ nC₇KET24+OH
R1250	C₇H₁₄OOH_3-5O₂ $→$ nC₇KET35+OH

参考文献 33

1	庞子凡, 蒋斌, 朱春英, 等. 微通道内CO₂吸收与传质及资源化利用的研究进展[J]. 化工学报, 2022, 73(1): 122-133.
	Pang Z F, Jiang B, Zhu C Y, et al. Progress of absorption, mass transfer and resource utilization of CO₂ in microchannels[J]. CIESC Journal, 2022, 73(1): 122-133.
2	喻健良, 朱海龙, 郭晓璐, 等. 超临界CO₂管道减压过程中的热力学特性[J]. 化工学报, 2017, 68(9): 3350-3357.
	Yu J L, Zhu H L, Guo X L, et al. Thermodynamic properties during depressurization process of supercritical CO₂ pipeline[J]. CIESC Journal, 2017, 68(9): 3350-3357.
3	裴普成, 刘永峰. 液氧固碳零排放内燃机: 102003305B[P]. 2012-12-26.
	Pei P C, Liu Y F. Liquid-oxygen carbon-fixation and zero-emission internal combustion engine: 102003305B[P]. 2012-12-26.
4	郑亮, 肖国炜, 王建昕, 等. 正庚烷喷雾扩散火焰中碳烟体积分数的定量测量[J]. 内燃机学报, 2014, 32(1): 14-19.
	Zheng L, Xiao G W, Wang J X, et al. Quantitative measurement of soot concentration in n-heptane fuel jets[J]. Transactions of CSICE, 2014, 32(1): 14-19.
5	Huo J L, Guan Y H, Zhang M, et al. Diesel spray auto-ignition in different oxidizing atmospheres[J]. Fuel, 2022, 328: 125308.
6	Peng C, Zou C, Xia W X, et al. Ignition delay times of n-butane and i-butane under O₂/CO₂ atmospheres: shock tube experiments and kinetic model[J]. Combustion and Flame, 2021, 234: 111646.
7	Tao C F, Liu B, Dou Y L, et al. The experimental study of flame height and lift-off height of propane diffusion flames diluted by carbon dioxide[J]. Fuel, 2021, 290: 119958.
8	Erete J I, Hughes K J, Ma L, et al. Effect of CO₂ dilution on the structure and emissions from turbulent, non-premixed methane-air jet flames[J]. Journal of the Energy Institute, 2017, 90(2): 191-200.
9	Bejarano P A, Levendis Y A. Single-coal-particle combustion in O₂/N₂ and O₂/CO₂ environments[J]. Combustion and Flame, 2008, 153(1/2): 270-287.
10	Mehl M, Pitz W J, Westbrook C K, et al. Kinetic modeling of gasoline surrogate components and mixtures under engine conditions[J]. Proceedings of the Combustion Institute, 2011, 33(1): 193-200.
11	Chen Y L, Chen J Y. Towards improved automatic chemical kinetic model reduction regarding ignition delays and flame speeds[J]. Combustion and Flame, 2018, 190: 293-301.
12	Shi Y, Ge H W, Brakora J L, et al. Automatic chemistry mechanism reduction of hydrocarbon fuels for HCCI engines based on DRGEP and PCA methods with error control[J]. Energy and Fuels, 2010, 24(3): 1646-1654.
13	Hwang Y T. On the proper usage of sensitivities of chemical kinetics models to the uncertainties in rate coefficients[J]. Proceedings of the National Science Council B.ROC, 1982, 6: 270-278.
14	Lu T F, Law C K. A directed relation graph method for mechanism reduction[J]. Proceedings of the Combustion Institute, 2005, 30(1): 1333-1341.
15	Lu T, Chen Q X. Shermo: a general code for calculating molecular thermochemistry properties[J]. Computational and Theoretical Chemistry, 2021, 1200: 113249.
16	Canneaux S, Bohr F, Henon E. KiSThelP: a program to predict thermodynamic properties and rate constants from quantum chemistry results[J]. Journal of Computational Chemistry, 2014, 35(1): 82-93.
17	马贵阳, 王岳, 张育才, 等. RNG k-ε模型在内燃机缸内湍流数值模拟中的应用[J]. 石油化工高等学校学报, 2002, 15(1): 55-59.
	Ma G Y, Wang Y, Zhang Y C, et al. Application of RNG k-ε model in numeral simulation of turbulent flow in cylinder[J]. Journal of Petrochemical Universities, 2002, 15(1): 55-59.
18	杨欢, 谢辉, 陈韬, 等. DME分布特征对微火源引燃汽油混合燃烧过程的影响[J]. 燃烧科学与技术, 2018, 24(5): 463-470.
	Yang H, Xie H, Chen T, et al. Effects of dimethyl ether distribution characteristics on micro flame ignition hybrid combustion[J]. Journal of Combustion Science and Technology, 2018, 24(5): 463-470.
19	魏明锐, 文华, 刘永长, 等. 喷雾过程液滴碰撞模型研究[J]. 内燃机学报, 2005, 23(6): 518-523.
	Wei M R, Wen H, Liu Y C, et al. Modeling study on droplets collision in spray process[J]. Transactions of CSICE, 2005, 23(6): 518-523.
20	Schmidt D P, Rutland C J. Reducing grid dependency in droplet collision modeling[J]. Journal of Engineering for Gas Turbines and Power, 2004, 126(2): 227-233.
21	Yuan S X, Fan Y G, Chen B, et al. Forming and stripping of the wall film and the influence on gas-liquid separation[J]. Asia-Pacific Journal of Chemical Engineering, 2020, 15(3): e2447.
22	Reitz R D, Diwakar R. Structure of high-pressure fuel sprays[C]//SAE Technical Paper Series. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 1987: 492-509.
23	Patterson M A, Reitz R D. Modeling the effects of fuel spray characteristics on diesel engine combustion and emission[C]//SAE Technical Paper Series. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 1998: 27-43.
24	Vasu S S, Davidson D F, Hanson R K, et al. Shock tube study of syngas ignition in rich CO₂ mixtures and determination of the rate of H+O₂+CO₂→HO₂+CO₂ [J]. Energy and Fuels, 2011, 25(3): 990-997.
25	贺振宗, 朱瑞韩, 董川徽, 等. WSGSA模型在C₂H₄/空气湍流扩散火焰温度和烟尘预测中的应用[J]. 南京航空航天大学学报(英文版), 2022, 39(4): 482-492.
	He Z Z, Zhu R H, Dong C H, et al. Application of WSGSA model in predicting temperature and soot in C₂H₄/air turbulent diffusion flame[J]. Transactions of Nanjing University of Aeronautics and Astronautics, 2022, 39(4): 482-492.
26	Masri A R, Dibble R W, Barlow R S. Chemical kinetic effects in nonpremixed flames of H₂/CO₂ fuel[J]. Combustion and Flame, 1992, 91(3/4): 285-309.
27	Zhou Y, Xie F, Yao M, et al. Investigation on stability and chemiluminescence characterization for liftoff inverse diffusion flames[J]. Combustion Science and Technology, 2021(2): 1-19.
28	Lu T, Chen F W. Quantitative analysis of molecular surface based on improved Marching Tetrahedra algorithm[J]. Journal of Molecular Graphics and Modelling, 2012, 38: 314-323.
29	吴博, 黄静梦, 谭桂珍, 等. 基于密度泛函理论研究碱性水溶液中乙内酰脲及其衍生物的结构及性质[J]. 化学通报, 2021, 84(6): 610-619.
	Wu B, Huang J M, Tan G Z, et al. DFT study on the structure and properties of hydantoin and its derivatives in the alkaline aqueous solution[J]. Chemistry, 2021, 84(6): 610-619.
30	马志豪, 吕恩雨, 董永超, 等. 碳氢燃料在激波管内的裂解试验与动力学研究[J]. 内燃机学报, 2022, 40(5): 420-429.
	Ma Z H, Lyu E Y, Dong Y C, et al. Experiment and kinetic study on pyrolysis of hydrocarbon fuel in shock tube[J]. Transactions of CSICE, 2022, 40(5): 420-429.
31	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.
	Luo Z M, Kang K. Simulative analysis of microscopic mechanism of CO₂ inhibiting methane-air chain explosion[J]. China Safety Science Journal, 2015, 25(5): 42-48.
32	Alfazazi A, Kuti O A, Naser N, et al. Two-stage Lagrangian modeling of ignition processes in ignition quality tester and constant volume combustion chambers [J]. Fuel, 2016, 185: 589-598.
33	Di H, He X, Zhang P, et al. Effects of buffer gas composition on low temperature ignition of iso-octane and n-heptane [J]. Combustion and Flame, 2014, 161(10): 2531-2538.

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O₂/CO₂氛围下正庚烷的燃烧机理研究

Quantum chemical analysis of n-heptane combustion mechanism under O₂/CO₂ atmosphere

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