基于碳氢喷射的柴油机尾气热管理模型
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摘要
针对尾气热管理系统进行了一维柴油催化氧化器(DOC)化学反应动力学与流动的耦合模型研究.基于已有的柴油机原排碳氢反应机理研究,对碳氢喷射尾气热管理系统进行了整合修正.模型主要考虑了系统在DOC上游安装的碳氢喷嘴喷入的柴油液滴,在DOC内部形成气态碳氢化合物的蒸发热解和催化反应过程.同时将柴油液滴蒸发热解过程进行改进优化,设计了一种"两步蒸发热解法"简化复杂的柴油蒸发热解过程,并给出了相应的阿伦尼乌斯型蒸发热解速率经验公式.模型基于GT-Power软件搭建,同时在柴油机上进行了稳态工况碳氢喷射升温试验,并利用试验数据针对模型进行了标定.结果表明:标定后的模型与试验动态结果误差较小,这一理论与工程标定相结合的模型研究方法可以用于国Ⅵ尾气热管理控制策略开发.
One-dimensional diesel oxidation catalyst(DOC)model coupled with chemical reaction kinetics was investigated on this system. Based on the previous research of the hydrocarbon reaction in engine original exhaust,the model was integrated and modified considering the diesel thermal management system with hydrocarbon dosing. The model mainly considered the evaporation and thermolysis process that diesel droplet injected by DOC upstream injector was transformed into gaseous hydrocarbon inside DOC. Simultaneously,the evaporation and thermolysis process of diesel droplet was optimized by a "two-step E-T method" to simplify the complex process of diesel evaporation and thermolysis. The rate formula of evaporation and thermolysis was given by Arrhenius form. The model was simulated on GT-Power and experimented on an engine displacement under steady-state conditions,with hydrocarbon dosing inducing temperature rising. Model was calibrated by experimental data. The result showed that the dynamic error between calibrated model and experiment was relatively small. This model research method which was combined by theory and engineering calibration could provide reference for control strategy development for China Ⅵ diesel exhaust thermal management.
One-dimensional diesel oxidation catalyst(DOC)model coupled with chemical reaction kinetics was investigated on this system. Based on the previous research of the hydrocarbon reaction in engine original exhaust,the model was integrated and modified considering the diesel thermal management system with hydrocarbon dosing. The model mainly considered the evaporation and thermolysis process that diesel droplet injected by DOC upstream injector was transformed into gaseous hydrocarbon inside DOC. Simultaneously,the evaporation and thermolysis process of diesel droplet was optimized by a "two-step E-T method" to simplify the complex process of diesel evaporation and thermolysis. The rate formula of evaporation and thermolysis was given by Arrhenius form. The model was simulated on GT-Power and experimented on an engine displacement under steady-state conditions,with hydrocarbon dosing inducing temperature rising. Model was calibrated by experimental data. The result showed that the dynamic error between calibrated model and experiment was relatively small. This model research method which was combined by theory and engineering calibration could provide reference for control strategy development for China Ⅵ diesel exhaust thermal management.
引文
[1]寇传富.满足京5+排放的柴油机排气热管理策略及试验研究[D].长沙:湖南大学机械与运载工程学院,2015.
[2]Rothe D,Knauer M,Emmerling G,et al.Emissions during active regeneration of a diesel particulate filter on a heavy duty diesel engine:Stationary tests[J].Journal of Aerosol Science,2015,90:14-25.
[3]田径,程义琳,刘忠长,等.柴油机微粒捕集器降怠速再生过程载体温度的控制[J].内燃机学报,2013,31(2):154-158.
[4]龚金科,江俊豪,刘伟强,等.柴油机微粒捕集器热再生场协同分析[J].内燃机学报,2016,34(4):346-351.
[5]刘宏威,张凯凯,姚广涛,等.采用缸内后喷和排气管喷油的DOC辅助DPF再生技术的研究[J].汽车工程,2015,37(4):391-395.
[6]Bai S,Chen G,Sun Q,et al.Influence of active control strategies on exhaust thermal management for diesel particular filter active regeneration[J].Applied Thermal Engineering,2017,119:297-303
[7]Parks J,Huff S,Kass M,et al.Characterization of incylinder techniques for thermal management of diesel aftertreatment[C]//SAE Paper.Rosemont,Illinois,USA,2007,2007-01-3997.
[8]Chen P,Wang J.Control-oriented model for integrated diesel engine and aftertreatment systems thermal management[J].Control Engineering Practice,2014,22(1):81-93.
[9]Bamber D W,Ambrose S L,McCarthy J E.Fuel injector optimization for diesel aftertreatment systems coupled with exhaust aftertreatment system performance on a heavy-duty diesel engine powered vehicle[C]//SAE Paper.Chicago,Illinois,USA,2010,2010-01-1940.
[10]Oh S H,Cavendish J C.Transients of monolithic catalytic converters:Response to step changes in feedstream temperature as related to controlling automobile emissions[J].Industrial&Engineering Chemistry Product Research&Development,1982,21(1):29-37.
[11]Lepreux O,Creff Y,Petit N.Model-based temperature control of a diesel oxidation catalyst[J].Journal of Process Control,2012,22(1):41-50.
[12]Sampara C,Bissett E,Chmielewski M.Global kinetics for a commercial diesel oxidation catalyst with two exhaust hydrocarbons[J].Industrial&Engineering Chemistry Research,2008,47(2):311-322.
[13]Sampara C,Bissett E,Assanis D.Hydrocarbon storage modeling for diesel oxidation catalysts[J].Chemical Engineering Science,2008,63(21):5179-5192.
[14]Kim Y,Nieuwstadt M,Stewart G,et al.Model predictive control of DOC temperature during DPF regeneration[C]//SAE Paper.Detroit,Michigan,USA,2014,2014-01-1165.
[15]Ning J,Yan F.Composite control of DOC-out temperature for DPF regeneration[J].IFAC Papers Online,2016,49(11):20-27.
[16]Tanaka Y,Takashi H,Makoto N,et al.Modeling of diesel oxidation catalyst[J].Industrial&Engineering Chemistry Research,2005,44(22):8205-8212.
[17]王翔,王旭江,范燕荣,等.不同气氛下柴油热解及热动力学特性分析[J].燃烧科学与技术,2014,20(4):335-340.
[18]干旭波.柴油机Urea-SCR系统还原剂添加过程的基础研究[D].杭州:浙江大学能源工程学院,2016.
[19]David K,Petr K,Milan K,et al.Catalytic converters for automobile diesel engines with adsorption of hydrocarbons on zeolites[J].Industrial&Engineering Chemistry Research,2005,44(25):9524-9534.
[2]Rothe D,Knauer M,Emmerling G,et al.Emissions during active regeneration of a diesel particulate filter on a heavy duty diesel engine:Stationary tests[J].Journal of Aerosol Science,2015,90:14-25.
[3]田径,程义琳,刘忠长,等.柴油机微粒捕集器降怠速再生过程载体温度的控制[J].内燃机学报,2013,31(2):154-158.
[4]龚金科,江俊豪,刘伟强,等.柴油机微粒捕集器热再生场协同分析[J].内燃机学报,2016,34(4):346-351.
[5]刘宏威,张凯凯,姚广涛,等.采用缸内后喷和排气管喷油的DOC辅助DPF再生技术的研究[J].汽车工程,2015,37(4):391-395.
[6]Bai S,Chen G,Sun Q,et al.Influence of active control strategies on exhaust thermal management for diesel particular filter active regeneration[J].Applied Thermal Engineering,2017,119:297-303
[7]Parks J,Huff S,Kass M,et al.Characterization of incylinder techniques for thermal management of diesel aftertreatment[C]//SAE Paper.Rosemont,Illinois,USA,2007,2007-01-3997.
[8]Chen P,Wang J.Control-oriented model for integrated diesel engine and aftertreatment systems thermal management[J].Control Engineering Practice,2014,22(1):81-93.
[9]Bamber D W,Ambrose S L,McCarthy J E.Fuel injector optimization for diesel aftertreatment systems coupled with exhaust aftertreatment system performance on a heavy-duty diesel engine powered vehicle[C]//SAE Paper.Chicago,Illinois,USA,2010,2010-01-1940.
[10]Oh S H,Cavendish J C.Transients of monolithic catalytic converters:Response to step changes in feedstream temperature as related to controlling automobile emissions[J].Industrial&Engineering Chemistry Product Research&Development,1982,21(1):29-37.
[11]Lepreux O,Creff Y,Petit N.Model-based temperature control of a diesel oxidation catalyst[J].Journal of Process Control,2012,22(1):41-50.
[12]Sampara C,Bissett E,Chmielewski M.Global kinetics for a commercial diesel oxidation catalyst with two exhaust hydrocarbons[J].Industrial&Engineering Chemistry Research,2008,47(2):311-322.
[13]Sampara C,Bissett E,Assanis D.Hydrocarbon storage modeling for diesel oxidation catalysts[J].Chemical Engineering Science,2008,63(21):5179-5192.
[14]Kim Y,Nieuwstadt M,Stewart G,et al.Model predictive control of DOC temperature during DPF regeneration[C]//SAE Paper.Detroit,Michigan,USA,2014,2014-01-1165.
[15]Ning J,Yan F.Composite control of DOC-out temperature for DPF regeneration[J].IFAC Papers Online,2016,49(11):20-27.
[16]Tanaka Y,Takashi H,Makoto N,et al.Modeling of diesel oxidation catalyst[J].Industrial&Engineering Chemistry Research,2005,44(22):8205-8212.
[17]王翔,王旭江,范燕荣,等.不同气氛下柴油热解及热动力学特性分析[J].燃烧科学与技术,2014,20(4):335-340.
[18]干旭波.柴油机Urea-SCR系统还原剂添加过程的基础研究[D].杭州:浙江大学能源工程学院,2016.
[19]David K,Petr K,Milan K,et al.Catalytic converters for automobile diesel engines with adsorption of hydrocarbons on zeolites[J].Industrial&Engineering Chemistry Research,2005,44(25):9524-9534.