基于化学反应机理的燃料重整柴油机工作过程数值模拟
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摘要
大气污染已经成为当今世界面临的一个难题,它会破坏生态系统和人类正常生存和发展的条件。大气污染的主要来源之一是汽车发动机,用仿真软件可以研究发动机排放生成机理,分析发动机参数对排放的影响,为降低发动机排放提供理论依据。CFD软件是目前国际上进行传热、传质、动量传递及燃烧、多相流和化学反应研究的有效工具,而FLUENT是目前功能最全面、使用最广泛的CFD软件之一。
本文对ZS195柴油机进行了燃料重整模拟计算,分析了在不同的模拟重整气下的柴油机气缸内部流场、湍流动能分布、温度分布、氧气浓度分布、柴油浓度分布、NOX浓度分布、碳烟排放浓度分布以及平均压力和温度分布。结果表明:掺CO后,柴油机的NOX排放增加,碳烟排放降低,NOX和碳烟的模拟值和试验值比较接近;掺H2、CO以及EGR后,可以同时降低柴油机的NOX和碳烟排放。
目前大型数值模拟用串行计算需要花费大量的时间,而采用并行计算有可能提高FLUENT软件模拟计算的速度。本文测试了各种并行计算方案对模拟计算速度提高的影响。结果表明,模拟计算量小的时候,并行计算不能明显地能够提高模拟计算的速度。模拟计算量大的时候,并行计算可以较明显地提高模拟计算的速度。LINUX系统的并行计算性能要好于WINDOWS XP系统的并行计算性能。计算机主频越高,并行计算性能越好。
The air pollution already become a problem of the world, it destroy the ecosystem and the condition of human survival and development normally. The engine is one of main sources of it. It can study the production mechanism of emissions with the simulation software, analyzes the emissions with different engine conditions, provide the theory basis to reduce the engine emissions. The software of CFD is the effective tool of the heat transfer, the mass transfer, the momentum transfer and the combustion, the polyphase flow and the chemical reaction research, and FLUENT is one of the software which has most comprehensive function and wide application.
Simulates fuel reformed of ZS195 diesel, analyzes the distribution of in cylinder flow field, turbulent kinetic energy, temperature, oxygen, diesel oil, NOX, soot, average pressure and average temperature. The result shows that the NOX emission increases and the soot emission reduces after mixing CO. Simulation value is close to experimental value. The NOX emission and soot emission reduce simultaneously after mixing H2, CO and EGR. The large-scale computation needs to cost many time with the serial computing now.
However it may enhance the computation speed of the FLUENT with the parallel computing. This article has tested the influence which each kind of parallel computing plan enhances the computation speed. The result shows that the parallel computing can not increase the computing speed obviously when amount of calculation is small. But it can when amount of calculation is big. The LINUX system is better than the WINDOWS XP system for the performance of parallel computing. The computer dominant frequency is higher, the parallel computing performance is better.
本文对ZS195柴油机进行了燃料重整模拟计算,分析了在不同的模拟重整气下的柴油机气缸内部流场、湍流动能分布、温度分布、氧气浓度分布、柴油浓度分布、NOX浓度分布、碳烟排放浓度分布以及平均压力和温度分布。结果表明:掺CO后,柴油机的NOX排放增加,碳烟排放降低,NOX和碳烟的模拟值和试验值比较接近;掺H2、CO以及EGR后,可以同时降低柴油机的NOX和碳烟排放。
目前大型数值模拟用串行计算需要花费大量的时间,而采用并行计算有可能提高FLUENT软件模拟计算的速度。本文测试了各种并行计算方案对模拟计算速度提高的影响。结果表明,模拟计算量小的时候,并行计算不能明显地能够提高模拟计算的速度。模拟计算量大的时候,并行计算可以较明显地提高模拟计算的速度。LINUX系统的并行计算性能要好于WINDOWS XP系统的并行计算性能。计算机主频越高,并行计算性能越好。
The air pollution already become a problem of the world, it destroy the ecosystem and the condition of human survival and development normally. The engine is one of main sources of it. It can study the production mechanism of emissions with the simulation software, analyzes the emissions with different engine conditions, provide the theory basis to reduce the engine emissions. The software of CFD is the effective tool of the heat transfer, the mass transfer, the momentum transfer and the combustion, the polyphase flow and the chemical reaction research, and FLUENT is one of the software which has most comprehensive function and wide application.
Simulates fuel reformed of ZS195 diesel, analyzes the distribution of in cylinder flow field, turbulent kinetic energy, temperature, oxygen, diesel oil, NOX, soot, average pressure and average temperature. The result shows that the NOX emission increases and the soot emission reduces after mixing CO. Simulation value is close to experimental value. The NOX emission and soot emission reduce simultaneously after mixing H2, CO and EGR. The large-scale computation needs to cost many time with the serial computing now.
However it may enhance the computation speed of the FLUENT with the parallel computing. This article has tested the influence which each kind of parallel computing plan enhances the computation speed. The result shows that the parallel computing can not increase the computing speed obviously when amount of calculation is small. But it can when amount of calculation is big. The LINUX system is better than the WINDOWS XP system for the performance of parallel computing. The computer dominant frequency is higher, the parallel computing performance is better.
引文
[1]史绍熙,苏万华.内燃机燃烧研究中的几个前沿问题[J].内燃机学报, 1990,(2).
[2]金国栋.内燃机燃烧学[M].武汉:华中科技大学出版社,1991.
[3]崔心存,金国栋.内燃机排气净化[M].武汉:华中科技大学出版社,1991.
[4]胡群.车用柴油机排放物有害成分的分析与控制[J].内燃机学报,2003(6).
[5]宋岩.柴油机NOx和PM排放控制技术的发展[J].徐州工程学院学报, 2007年4月,Vol.22 No 4.
[6]王建听,傅立新,黎维彬.汽车排气污染治理及催化转化器[M].北京:化学工业出版社,2000.
[7]崔心存,金国栋。内燃机排气净化[M].华中理工大学出版社, 1991, 200-210。
[8]杜宝国,许锋,高希彦,鲍镇。在直喷式柴油机上进行HCCI新概念燃烧的探索研究[J].热科学与技术,2007,6(1):80-84。
[9]贺泓,翁端,资新运。柴油车尾气排放污染控制技术综述[J].环境科学,2007,28(6):1169-1177.
[10] G. Ulrich,B. Schumann. Engines and exhaust after treatment systems for future automotive applications[J]. Solid State Ionics, 2006,177(26-32): 2291-2296.
[11]吴涛涛,张会生.重整制氢技术及其研究进展[J].能源技术,2006年8月. Vol.27 No4.
[12] Andrew E Lutz,Robert W Bradshaw. Thermodynamic analysis of hydrogen production by partial oxidation reforming [J]. International Journal of Hydrogen Energy,2004,29: 809-816.
[13]潘相敏,马建新,周伟,等.燃料电池动力车车载甲醇重整器研究进展[J].能源技术,2004,25(1):21~27.
[14] Alejo I,Lago R,Pena M A,et al. Partial oxidation of methanol to produce hydrogen over Cu-Zn-based catalysts [J]. Appl Catal A,1997,162(1-2): 281-297.
[15] Traxel B E,Hohn K L. Partial oxidation of methanol at millisecond contact times[J]. Appl Catal A, 2003, 244(1): 129-140
[16]洪学伦,任素贞.甲醇自热重整制氢集成式反应器的研究[J].天然气化工:C1化学与化工-2007年5期
[17] A.Tsolakis.A.Megaritis.Catalytic exhaust gas fuel reforming for dieselengines—effects of water addition on hydrogen production and fuel conversion efficiency.International Journal of Hydrogen Energy 2004,29(13):1409～1419
[18]朱文良,韩伟,张小亮,熊国兴,杨维慎.汽油与水和氧混合重整制氢气[J].催化学报,2005年6月.Vol.26 No 6.
[19] A. Tsolakis,A. Megaritis,and M. L. Wyszynski .Application of Exhaust Gas Fuel Reforming in Compression Ignition Engines Fueled by Diesel and Biodiesel Fuel Mixtures[J]. Energy & Fuels,2003,17,1464-1473.
[20] A. Tsolakis , A. Megaritis.Reaction Profiles during Exhaust-Assisted Reforming of Diesel Engine Fuels[J]. Energy & Fuels,2005,19, 744-752.
[21]朱文良,韩伟,张小亮,熊国兴,杨维慎.汽油与水和氧混合重整制氢气[J].催化学报,2005年6月.Vol.26 No 6.
[22]张新荣,史鹏飞,刘春涛.甲醇水蒸气重整制氢Cu/ ZnO/ Al2O3催化剂的研究[J].燃料化学学报,2003年6月.Vol.31 No 3.
[23]曲延涛,张国强.废热重整甲醇内燃机一涡轮复合循环[J].节能技术, 2005年5月第三期.
[24]张红升,王桂平.柴油机NOx和PM排放控制技术的发展[J].山东内燃机,2004年第三期.
[25] A.Tsolakis.A.Megaritis.Catalytic exhaust gas fuel reforming for diesel engines—effects of water addition on hydrogen production and fuel conversion efficiency.International Journal of Hydrogen Energy 2004,29(13):1409～1419
[26] A.Tsolakis.A.Megaritis.Exhaust gas assisted reforming of rapeseed methyl ester for reduced exhaust emissions of CI engines . Biomass and Bioenergy.2004,27(5):493—505
[27] L.Bromberg.D.R.Cohn.Compact plasmatron—boosted hydrogen generation technology for vehicular applications . International Journal of Hydrogen Energy 1999,24(4):341—350
[28]郑冕,吴丽娟.任意区域的网格划分方法分类[J].沈阳师范大学学报(自然科学版).第23卷第4期,2005(12):364～367.
[29]李学干,徐甲.并行处理技术[M].北京:北京理工大学出版社,1994.9.
[30]金兰.并行处理计算机结构[M].北京:国防工业出版社,1982.
[31]李敏,张宜生,李德群.用于并行计算的PC集群系统构建[J].计算机应用研究,2009,26(3):1042-1043.
[32]王志,帅石金,王建昕,等.采用并行计算和简化机理的HCCI发动机多维模拟[J].内燃机学报,2008,26(2):116-120.
[33] O. Hardenburg,F. Hase. An Empirical Formula for Computing the Pressure Rise Delay of a Fuel from its Cetane Number and from the Relevant Parameters of Direct Injection Diesel Engine[C]. SAE Paper 790493,1979.
[34]庄兵,罗福强,李占成,黄贤龙.内燃机废气再循环(EGR)率评价方法研究[J].农机化研究, 2006, 8:203-205.
[35]纪常伟,韩爱民,赵勇,马慧.内燃机废气再循环率评价方法的试验研究[J].北京工业大学学报, 2004, 30(3):338-341.
[2]金国栋.内燃机燃烧学[M].武汉:华中科技大学出版社,1991.
[3]崔心存,金国栋.内燃机排气净化[M].武汉:华中科技大学出版社,1991.
[4]胡群.车用柴油机排放物有害成分的分析与控制[J].内燃机学报,2003(6).
[5]宋岩.柴油机NOx和PM排放控制技术的发展[J].徐州工程学院学报, 2007年4月,Vol.22 No 4.
[6]王建听,傅立新,黎维彬.汽车排气污染治理及催化转化器[M].北京:化学工业出版社,2000.
[7]崔心存,金国栋。内燃机排气净化[M].华中理工大学出版社, 1991, 200-210。
[8]杜宝国,许锋,高希彦,鲍镇。在直喷式柴油机上进行HCCI新概念燃烧的探索研究[J].热科学与技术,2007,6(1):80-84。
[9]贺泓,翁端,资新运。柴油车尾气排放污染控制技术综述[J].环境科学,2007,28(6):1169-1177.
[10] G. Ulrich,B. Schumann. Engines and exhaust after treatment systems for future automotive applications[J]. Solid State Ionics, 2006,177(26-32): 2291-2296.
[11]吴涛涛,张会生.重整制氢技术及其研究进展[J].能源技术,2006年8月. Vol.27 No4.
[12] Andrew E Lutz,Robert W Bradshaw. Thermodynamic analysis of hydrogen production by partial oxidation reforming [J]. International Journal of Hydrogen Energy,2004,29: 809-816.
[13]潘相敏,马建新,周伟,等.燃料电池动力车车载甲醇重整器研究进展[J].能源技术,2004,25(1):21~27.
[14] Alejo I,Lago R,Pena M A,et al. Partial oxidation of methanol to produce hydrogen over Cu-Zn-based catalysts [J]. Appl Catal A,1997,162(1-2): 281-297.
[15] Traxel B E,Hohn K L. Partial oxidation of methanol at millisecond contact times[J]. Appl Catal A, 2003, 244(1): 129-140
[16]洪学伦,任素贞.甲醇自热重整制氢集成式反应器的研究[J].天然气化工:C1化学与化工-2007年5期
[17] A.Tsolakis.A.Megaritis.Catalytic exhaust gas fuel reforming for dieselengines—effects of water addition on hydrogen production and fuel conversion efficiency.International Journal of Hydrogen Energy 2004,29(13):1409～1419
[18]朱文良,韩伟,张小亮,熊国兴,杨维慎.汽油与水和氧混合重整制氢气[J].催化学报,2005年6月.Vol.26 No 6.
[19] A. Tsolakis,A. Megaritis,and M. L. Wyszynski .Application of Exhaust Gas Fuel Reforming in Compression Ignition Engines Fueled by Diesel and Biodiesel Fuel Mixtures[J]. Energy & Fuels,2003,17,1464-1473.
[20] A. Tsolakis , A. Megaritis.Reaction Profiles during Exhaust-Assisted Reforming of Diesel Engine Fuels[J]. Energy & Fuels,2005,19, 744-752.
[21]朱文良,韩伟,张小亮,熊国兴,杨维慎.汽油与水和氧混合重整制氢气[J].催化学报,2005年6月.Vol.26 No 6.
[22]张新荣,史鹏飞,刘春涛.甲醇水蒸气重整制氢Cu/ ZnO/ Al2O3催化剂的研究[J].燃料化学学报,2003年6月.Vol.31 No 3.
[23]曲延涛,张国强.废热重整甲醇内燃机一涡轮复合循环[J].节能技术, 2005年5月第三期.
[24]张红升,王桂平.柴油机NOx和PM排放控制技术的发展[J].山东内燃机,2004年第三期.
[25] A.Tsolakis.A.Megaritis.Catalytic exhaust gas fuel reforming for diesel engines—effects of water addition on hydrogen production and fuel conversion efficiency.International Journal of Hydrogen Energy 2004,29(13):1409～1419
[26] A.Tsolakis.A.Megaritis.Exhaust gas assisted reforming of rapeseed methyl ester for reduced exhaust emissions of CI engines . Biomass and Bioenergy.2004,27(5):493—505
[27] L.Bromberg.D.R.Cohn.Compact plasmatron—boosted hydrogen generation technology for vehicular applications . International Journal of Hydrogen Energy 1999,24(4):341—350
[28]郑冕,吴丽娟.任意区域的网格划分方法分类[J].沈阳师范大学学报(自然科学版).第23卷第4期,2005(12):364～367.
[29]李学干,徐甲.并行处理技术[M].北京:北京理工大学出版社,1994.9.
[30]金兰.并行处理计算机结构[M].北京:国防工业出版社,1982.
[31]李敏,张宜生,李德群.用于并行计算的PC集群系统构建[J].计算机应用研究,2009,26(3):1042-1043.
[32]王志,帅石金,王建昕,等.采用并行计算和简化机理的HCCI发动机多维模拟[J].内燃机学报,2008,26(2):116-120.
[33] O. Hardenburg,F. Hase. An Empirical Formula for Computing the Pressure Rise Delay of a Fuel from its Cetane Number and from the Relevant Parameters of Direct Injection Diesel Engine[C]. SAE Paper 790493,1979.
[34]庄兵,罗福强,李占成,黄贤龙.内燃机废气再循环(EGR)率评价方法研究[J].农机化研究, 2006, 8:203-205.
[35]纪常伟,韩爱民,赵勇,马慧.内燃机废气再循环率评价方法的试验研究[J].北京工业大学学报, 2004, 30(3):338-341.