进气温度对甲醇发动机燃烧及醇醛类排放影响研究
|
摘要
针对甲醇发动机冷起动醇醛类排放物高的问题,基于一款经柴油机改装的缸内直喷点燃式甲醇发动机为模型,采用AVL-FIRE软件耦合甲醇氧化反应机理,分析了不同进气温度对甲醇发动机冷起动燃烧、甲醛和未燃甲醇排放的影响,结果表明,当进气温度由283 K提高到293 K,燃烧滞燃期缩短了1.3°CA,最高气缸压力和最高燃烧温度分别升高0.59MPa和165 K,未燃甲醇和甲醛排放浓度下降幅度分别为49%和32%;当进气温度由293 K升高到313 K,提高进气温度对改善燃烧和降低醇醛排放作用有一定程度下降;当进气温度超过313 K提高进气温度对改善燃烧和降低醇醛排放效果微弱。提高进气温度能够促进缸内甲醇的蒸发,改善缸内混合气浓度分布和冷起动燃烧,降低甲醛和未燃甲醇排放。
To analyze the cause of high unregulated emission of alcohol aldehyde of methanol engine during cold starting, the effect of different intake temperatures on combustion and formaldehyde and unburned methanol unregulated emission of a direct injection spark ignition methanol engine refitted from diesel engine during cold starting was simulated by using AVL-FIRE coupling methanol chemical kinetics reaction mechanism. The research results show that, when intake temperature is increased from 283 K to 293 K, the ignition delay is reduced by 1.3°CA, and the maximum in-cylinder pressure and combustion temperature is increased by 0.59 MPa and 165 K, concentration of unburned methanol and formaldehyde emission is reduced by 49% and 32%, respectively; when the intake temperature further is increased from 293 K to 313 K, the effect of increasing intake temperature on combustion and unregulated emission decreases; while it plays little role improving combustion and reduce unregulated emissions when the intake temperature exceeds 313 K. Improving intake temperature can accelerate evaporation of methanol inside cylinder, improve distribution of in-cylinder gas mixture concentration and cold start burning, reduce emission of formaldehyde and unburned methanol.
To analyze the cause of high unregulated emission of alcohol aldehyde of methanol engine during cold starting, the effect of different intake temperatures on combustion and formaldehyde and unburned methanol unregulated emission of a direct injection spark ignition methanol engine refitted from diesel engine during cold starting was simulated by using AVL-FIRE coupling methanol chemical kinetics reaction mechanism. The research results show that, when intake temperature is increased from 283 K to 293 K, the ignition delay is reduced by 1.3°CA, and the maximum in-cylinder pressure and combustion temperature is increased by 0.59 MPa and 165 K, concentration of unburned methanol and formaldehyde emission is reduced by 49% and 32%, respectively; when the intake temperature further is increased from 293 K to 313 K, the effect of increasing intake temperature on combustion and unregulated emission decreases; while it plays little role improving combustion and reduce unregulated emissions when the intake temperature exceeds 313 K. Improving intake temperature can accelerate evaporation of methanol inside cylinder, improve distribution of in-cylinder gas mixture concentration and cold start burning, reduce emission of formaldehyde and unburned methanol.
引文
[1] Shamsul N S. An Overview on the Production of Bio-Methanol as Potential Renewable Energy. Renewable and Sustainable Energy Reviews, 2014,33(1):578-588.
[2]宫长明,彭乐高,孙景震,等.喷嘴开启压力对DISI甲醇发动机燃烧和排放的影响[J].车用发动机, 2015(3):70-75.
[3]姚春德,曾丽丽,耿鹏,等.甲醇汽油发动机燃烧及其醇醛排放特性的研究[J].汽车工程, 2014, 36(6):657-662.
[4]宫长明,宫宝利,彭乐高,等.点火时刻对甲醇发动机燃烧及非法规排放的影响[J].车用发动机, 2017(6):25-29+35.
[5]刘宗巍,史天泽,郝瀚,等.中国汽车技术的现状、发展需求与未来方向[J].汽车技术, 2017(1):1-6+47.
[6]袁宝良,洪建海,孙呈祥,等.甲醇发动机低温起动措施试验研究[J].汽车技术, 2017(10):12-17.
[7]李骏,张晓艳,付磊,等.汽车低碳化与动力总成技术创新[J].汽车技术, 2017(4):1-5.
[8] Boam D J, Clark T A, Hobbs K E. The Influence of Fuel Management on Unburnt Hydrocarbon Emissions During the ECE15 and US FTP Drive Cycles. SAE Paper,1995:950930.
[9] Fukihiro T, Akio Y, Surnio I, et al. Study of Mileage-Related Formaldehyde Emission from Methanol Fueled Vehicles.SAE Paper, 1990:900705.
[10]宫长明,李骏,于秀敏,等.冷起动时甲醇掺烧液化气发动机的甲醛和未燃甲醇排放[J].西安交通大学学报,2010, 44(5):21-25.
[11] Held T,Dryer F.A Comprehensive Mechanism for Methanol Oxidation. International Journal of Chemical Kinetics 1998,30(11):805-830.
[12] Zhen X D, Wang Y. Numerical Analysis on Original Emissions for a Spark Ignition Methanol Engine Based on Detailed Chemical Kinetics[J]. Renewable Energy, 2015,81:43-51.
[13]罗渝然,俞书勤,张祖德,等.再谈什么是活化能——Arrhenius活化能的定义、解释以及容易混淆的物理量[J].大学化学, 2010, 25(3):35-42.
[14]刘方杰,刘圣华,魏衍举,等.甲醇氧化生成甲醛排放的影响因素[J].内燃机学报, 2014, 32(2):166-171.
[2]宫长明,彭乐高,孙景震,等.喷嘴开启压力对DISI甲醇发动机燃烧和排放的影响[J].车用发动机, 2015(3):70-75.
[3]姚春德,曾丽丽,耿鹏,等.甲醇汽油发动机燃烧及其醇醛排放特性的研究[J].汽车工程, 2014, 36(6):657-662.
[4]宫长明,宫宝利,彭乐高,等.点火时刻对甲醇发动机燃烧及非法规排放的影响[J].车用发动机, 2017(6):25-29+35.
[5]刘宗巍,史天泽,郝瀚,等.中国汽车技术的现状、发展需求与未来方向[J].汽车技术, 2017(1):1-6+47.
[6]袁宝良,洪建海,孙呈祥,等.甲醇发动机低温起动措施试验研究[J].汽车技术, 2017(10):12-17.
[7]李骏,张晓艳,付磊,等.汽车低碳化与动力总成技术创新[J].汽车技术, 2017(4):1-5.
[8] Boam D J, Clark T A, Hobbs K E. The Influence of Fuel Management on Unburnt Hydrocarbon Emissions During the ECE15 and US FTP Drive Cycles. SAE Paper,1995:950930.
[9] Fukihiro T, Akio Y, Surnio I, et al. Study of Mileage-Related Formaldehyde Emission from Methanol Fueled Vehicles.SAE Paper, 1990:900705.
[10]宫长明,李骏,于秀敏,等.冷起动时甲醇掺烧液化气发动机的甲醛和未燃甲醇排放[J].西安交通大学学报,2010, 44(5):21-25.
[11] Held T,Dryer F.A Comprehensive Mechanism for Methanol Oxidation. International Journal of Chemical Kinetics 1998,30(11):805-830.
[12] Zhen X D, Wang Y. Numerical Analysis on Original Emissions for a Spark Ignition Methanol Engine Based on Detailed Chemical Kinetics[J]. Renewable Energy, 2015,81:43-51.
[13]罗渝然,俞书勤,张祖德,等.再谈什么是活化能——Arrhenius活化能的定义、解释以及容易混淆的物理量[J].大学化学, 2010, 25(3):35-42.
[14]刘方杰,刘圣华,魏衍举,等.甲醇氧化生成甲醛排放的影响因素[J].内燃机学报, 2014, 32(2):166-171.