低温等离子体净化装置对降低汽油机尾气排放污染的实验研究
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摘要
汽车工业的飞速发展带动了经济的发展,但同时也不可避免地对自然环境造成严重的污染。在排放法规日益严格的今天,治理汽车尾气排放已成为十分紧迫的任务。现今广泛使用的三元催化技术尽管能高效地控制汽车尾气污染,但由于制造三元催化器所需的贵金属的资源日趋紧张以及废弃的三元催化器会对环境造成二次污染等问题,使尽快找到三元催化器的替代产品成为各国研究的热点。本文提出的利用高压脉冲低温等离子体净化汽油机尾气的方法为治理汽车尾气排放提供了一种新的思路和方法。
本文首先基于气体放电的基本理论对高压脉冲放电产生低温等离子体的机理进行了研究,分析了所产生的低温等离子体中有效成分如O3、O、OH等与汽油机的主要排放污染物NOX、CO、HC等发生化学反应的过程,弄清了等离子体净化汽油机尾气的机理,为低温等离子体净化汽油机尾气建立了理论基础。然后,我们通过对现有的各种等离子体反应器进行比较分析,同时结合实际条件设计了线筒式高压脉冲低温等离子体净化装置。在设计电源时,我们主要参考了目前常用的各种等离子体净化气体污染物所使用的电源电压形式、放电参数和电源方案,初步选择了所要使用的电源系统,同时结合已设计的等离子体净化装置和实验条件,最终决定采用间隙开关式高压脉冲电源。
为了得到电源在等离子体净化装置上的最佳参数匹配,我们在常温常压下进行了标准气体的模拟试验。通过对实验结果的分析,我们得到了该电源在净化汽油机尾气时的最佳参数匹配。
在此基础上,为了验证该等离子体净化装置在实际处理汽油机尾气时的效果,我们在重庆大学内燃机实验室做了汽油发动机台架实验。通过实验,我们发现该等离子体净化装置对汽油机排放的有害气体有较好的去除效果,同时也在对实验结果的分析中找出了净化效率随发动机工况变化的规律。最后,在长安汽车公司环境检测实验室做了整车排放实验,进一步证明了低温等离子体技术在净化汽车尾气方面能达到较好的效果。
Rapid development of the automobile industry has led the rapid economic development, but also inevitably caused the serious pollution to the environment. The vehicle emission regulations are being strieter today, so controlling vehicle emissions has become the extremely urgent duty. Technology of tri-catalysis which is wide-spread used presently plays an important role in controlling automobile exhaust, but the costly metals which are used to make tri-catalysis device are limited and discarded tri-catalysis device will bring second-pollution to environment. Thus, finding out the substitutes is becoming the research focus in the world. Technology which is utilizing non-thermal plasma engendered by high voltage pulse to purify contaminative exhaust of gasoline engine provides a new way of thinking and method.
Firstly, the mechanism of non-thermal plasma engendered by high voltage pulse is researched by studying the basic theory of discharge in this thesis, then the process of effective compositions such as O3, O, OH and so on making chemical reaction with the main contaminative gases such as NOX, CO and HC is studied. Finally, the mechanism of non-thermal plasma purifying contaminative gases of engine is made clear, which establishes a theoretical foundation for non-thermal plasma purifying contaminative gases of engine. Subsequently, according to analysis of structure of kinds of existing plasma purifiers and actual condition, we design a high voltage pulse non-thermal plasma purifier. In the process of designing power, we mainly consult voltage-shape, parameter and scheme of power which are frequently used to give birth to non-thermal plasma for purifying contaminative gases and unify the plasma purifier and the actual condition, finally the plan of interval-switch high voltage and pulse power system is adopted.
To obtain the most suitable parameters match, simulative experiments of standard gases are done in normal temperature and atmospheric pressure. Through analyzing of experiment results, we obtain the most suitable parameters match for the high voltage and pulse power in purifying contaminative exhaust of engine.
In the foundation, for testing purification effect of plasma purifier disposing of contaminative gases of engine, pedestal experiment of engine is done in Chongqing university engine laboratory. That plasma purifier could get good effect in disposing contaminative exhaust is proved. At the same times, the rules of purification effect with engine’s work condition are finding. Lastly, exhaust experiment of whole vehicle is done in environment examination laboratory of Chang’an corporation, the results furtherly illustrate that plasma purifier could get good effect in disposing contaminative exhaust.
本文首先基于气体放电的基本理论对高压脉冲放电产生低温等离子体的机理进行了研究,分析了所产生的低温等离子体中有效成分如O3、O、OH等与汽油机的主要排放污染物NOX、CO、HC等发生化学反应的过程,弄清了等离子体净化汽油机尾气的机理,为低温等离子体净化汽油机尾气建立了理论基础。然后,我们通过对现有的各种等离子体反应器进行比较分析,同时结合实际条件设计了线筒式高压脉冲低温等离子体净化装置。在设计电源时,我们主要参考了目前常用的各种等离子体净化气体污染物所使用的电源电压形式、放电参数和电源方案,初步选择了所要使用的电源系统,同时结合已设计的等离子体净化装置和实验条件,最终决定采用间隙开关式高压脉冲电源。
为了得到电源在等离子体净化装置上的最佳参数匹配,我们在常温常压下进行了标准气体的模拟试验。通过对实验结果的分析,我们得到了该电源在净化汽油机尾气时的最佳参数匹配。
在此基础上,为了验证该等离子体净化装置在实际处理汽油机尾气时的效果,我们在重庆大学内燃机实验室做了汽油发动机台架实验。通过实验,我们发现该等离子体净化装置对汽油机排放的有害气体有较好的去除效果,同时也在对实验结果的分析中找出了净化效率随发动机工况变化的规律。最后,在长安汽车公司环境检测实验室做了整车排放实验,进一步证明了低温等离子体技术在净化汽车尾气方面能达到较好的效果。
Rapid development of the automobile industry has led the rapid economic development, but also inevitably caused the serious pollution to the environment. The vehicle emission regulations are being strieter today, so controlling vehicle emissions has become the extremely urgent duty. Technology of tri-catalysis which is wide-spread used presently plays an important role in controlling automobile exhaust, but the costly metals which are used to make tri-catalysis device are limited and discarded tri-catalysis device will bring second-pollution to environment. Thus, finding out the substitutes is becoming the research focus in the world. Technology which is utilizing non-thermal plasma engendered by high voltage pulse to purify contaminative exhaust of gasoline engine provides a new way of thinking and method.
Firstly, the mechanism of non-thermal plasma engendered by high voltage pulse is researched by studying the basic theory of discharge in this thesis, then the process of effective compositions such as O3, O, OH and so on making chemical reaction with the main contaminative gases such as NOX, CO and HC is studied. Finally, the mechanism of non-thermal plasma purifying contaminative gases of engine is made clear, which establishes a theoretical foundation for non-thermal plasma purifying contaminative gases of engine. Subsequently, according to analysis of structure of kinds of existing plasma purifiers and actual condition, we design a high voltage pulse non-thermal plasma purifier. In the process of designing power, we mainly consult voltage-shape, parameter and scheme of power which are frequently used to give birth to non-thermal plasma for purifying contaminative gases and unify the plasma purifier and the actual condition, finally the plan of interval-switch high voltage and pulse power system is adopted.
To obtain the most suitable parameters match, simulative experiments of standard gases are done in normal temperature and atmospheric pressure. Through analyzing of experiment results, we obtain the most suitable parameters match for the high voltage and pulse power in purifying contaminative exhaust of engine.
In the foundation, for testing purification effect of plasma purifier disposing of contaminative gases of engine, pedestal experiment of engine is done in Chongqing university engine laboratory. That plasma purifier could get good effect in disposing contaminative exhaust is proved. At the same times, the rules of purification effect with engine’s work condition are finding. Lastly, exhaust experiment of whole vehicle is done in environment examination laboratory of Chang’an corporation, the results furtherly illustrate that plasma purifier could get good effect in disposing contaminative exhaust.
引文
[1] V.Ravi, Young Sun Mok. Catalyst-Packed Non-Thermal Plasma Reactor for Removal of Nitrogen Oxides[J]. Plasma science &Technology, Vol.5, No.1, 2003.
[2] Masaaki Okubo, Member. Electric Air Cleaner Composed of Non-thermal Plasma Reactor and Electrostatic Precipitator[J]. IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS, VOL. 37, NO. 5, SEPTEMBER/OCTOBER 2001
[3] T. Yamamoto and C. L. Yang. Plasma desorption and decomposition[J]. Proceedings of the IEEE-IAS Annual Meeting, Saint Louis MO, October 12-16, pp. 1877-1883, 1998.
[4] J.-O. Chae. Non-thermal plasma for diesel exhaust treatment[J]. Journal of Electrostatics 57, 2003, 251-262.
[5]张武.非平衡等离子体改善柴油机排放的研究[D].大连理工大学硕士学位论文.
[6]吴海涛等.低温等离子体对汽油发动机排放特性影响的研究[D].四川兵工学报, 2006.5.
[7] Ran Zhenya,XiaGang. An experimental study on the removal gas engine exhaust by low temperature plasma technology[C].国际机械传动学术会议, ICMT2006, 2006.9.
[8]刘峥,王建昕,发动机原理教程[M].清华大学出版社.
[9] Qi SUN. Ai Min ZHU,Plasma-catalytic Selective Reduction of NO with C2H4 in the Presence of Excess Oxygen[J]. Chinese Chemical Letters Vol. 16, No. 6, pp 839-842, 2005.
[10]孙业保,车用内燃机[M].北京理工大学出版社.
[11]沈振华等.脉冲电晕放电对减少内燃机有害排放的研究[J].沈阳航空工业学院学报, Jun 2004. Vol.21, No.3.
[12]李兴虎.汽车排气污染与控制[M].机械工业出版社.
[13]周玉明.内燃机废气排放及控制技术[M].人民交通出版社.
[14]宋年秀,王丰元.电喷发动机[M].人民交通出版社.
[15] T. Yamamoto, M. Okubo, K. Hayakawa, and K. Kitaura. Towards ideal NOX control technology using plasma-chemical hybrid process[J]. IEEE Trans. Industry Applications, 37-5, pp.1492-1498, 2001.
[16]杨津基.气体放电[M].科学出版社.
[17]冉振亚.绿色汽车[M].香港社会科学出版社.
[18]郭玉芳等.废气治理的低温等离子体-催化协同净化技术[J].环境污染治理技术与设备, Jun 2003. Vol.4,No.7
[19]赵文华等.应用等离子体净化尾气中NO的研究[J].环境污染治理技术与设备, May 2002. Vol.3,No.5
[20]王喜眉等.介质阻挡放电净化汽车尾气中CO的实验研究[J].山西科技, 2005年第一期.
[21] Jae-Duk Moon, Geun-Taek Lee. SO2 and CO Gas Removal and Discharge Characteristics of a Nonthermal Plasma Reactor in a Crossed DC Magnetic Field[J]. IEEE Transactions on Industrv Amlications, Vol. 29, No. 4, pp.781-786, 1993.
[22]张春润等.介质阻挡放电净化汽车尾气NOX和HC的应用研究[J].高技术通讯, 2004.3.
[23]蒋洁敏等.非平衡态等离子体作用下一氧化碳的转化[J].化学世界, 2002年增刊.
[24] Masaaki Okubo, Member. NOX Reduction Aftertreatment System Using Nitrogen Nonthermal Plasma Desorption, NOX Reduction Aftertreatment System Using Nitrogen Nonthermal Plasma Desorption[J]. IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS, VOL.41, NO.4, JULY/AUGUST 2005.
[25]叶丽华等.低温等离子体净化汽车尾气中NO的试验研究[J].农业装备技术, Dec.2004, Vol.30 No.6.
[26]徐卡秋.等离子体改性燃油对汽车尾气中NO生成的抑制作用[J].四川大学学报(自然科学版), Aug.2005, Vol.42 No.4.
[27] B.S.Rajanikanth. Unfiltered Diesel Engine Exhaust Treatment by Discharge Plasma: Effect of Soot Oxidation[J]. Plasma science &Technology,Vol.6,No.5,Oct 2004.
[28]曾科等.采用低温等离子体技术降低柴油机有害排放物的研究[J].内燃机学报, Vol.21(2003)No.1.
[29] B.S.Rajanikanth. A Cascaded Discharge Plasma-Adsorbent Technique for Engine Exhaust Treatment[J]. Plasma science &Technology,Vol.5,No.3(2003)
[30]许洪军.柴油机尾气氮氧化物的机外净化技术研究[J].内燃机, No.6 Dec.2004.
[31]王燕等. DBD等离子体及其应用技术的发展[J].自然杂志, Vol.24 No.5.
[32] V.Ravi, Young Sun Mok. Studies on Nitrogen Oxides Removal Using Plasma Assisted Catalytic Reactor[J]. Plasma science &Technology,Vol.5,No.6(2003).
[33]张仁熙.等离子体技术在环境保护中的应用[J].环境保护, 2000年第20期.
[34] Koichi Takaki, Tamiya Fujiwara. Multipoint Barrier Discharge Process for Removal of NOX from Diesel Engine Exhaust[J]. IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 29, NO. 3, JUNE 2001.
[35]都基峻.低温等离子体处理气态污染物[J].污染防治技术, Mar 2000, Vol.13 No.6.
[36]杨武.低温等离子体空气净化原理及应用[J].电工技术杂志, 2003年第3期.
[2] Masaaki Okubo, Member. Electric Air Cleaner Composed of Non-thermal Plasma Reactor and Electrostatic Precipitator[J]. IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS, VOL. 37, NO. 5, SEPTEMBER/OCTOBER 2001
[3] T. Yamamoto and C. L. Yang. Plasma desorption and decomposition[J]. Proceedings of the IEEE-IAS Annual Meeting, Saint Louis MO, October 12-16, pp. 1877-1883, 1998.
[4] J.-O. Chae. Non-thermal plasma for diesel exhaust treatment[J]. Journal of Electrostatics 57, 2003, 251-262.
[5]张武.非平衡等离子体改善柴油机排放的研究[D].大连理工大学硕士学位论文.
[6]吴海涛等.低温等离子体对汽油发动机排放特性影响的研究[D].四川兵工学报, 2006.5.
[7] Ran Zhenya,XiaGang. An experimental study on the removal gas engine exhaust by low temperature plasma technology[C].国际机械传动学术会议, ICMT2006, 2006.9.
[8]刘峥,王建昕,发动机原理教程[M].清华大学出版社.
[9] Qi SUN. Ai Min ZHU,Plasma-catalytic Selective Reduction of NO with C2H4 in the Presence of Excess Oxygen[J]. Chinese Chemical Letters Vol. 16, No. 6, pp 839-842, 2005.
[10]孙业保,车用内燃机[M].北京理工大学出版社.
[11]沈振华等.脉冲电晕放电对减少内燃机有害排放的研究[J].沈阳航空工业学院学报, Jun 2004. Vol.21, No.3.
[12]李兴虎.汽车排气污染与控制[M].机械工业出版社.
[13]周玉明.内燃机废气排放及控制技术[M].人民交通出版社.
[14]宋年秀,王丰元.电喷发动机[M].人民交通出版社.
[15] T. Yamamoto, M. Okubo, K. Hayakawa, and K. Kitaura. Towards ideal NOX control technology using plasma-chemical hybrid process[J]. IEEE Trans. Industry Applications, 37-5, pp.1492-1498, 2001.
[16]杨津基.气体放电[M].科学出版社.
[17]冉振亚.绿色汽车[M].香港社会科学出版社.
[18]郭玉芳等.废气治理的低温等离子体-催化协同净化技术[J].环境污染治理技术与设备, Jun 2003. Vol.4,No.7
[19]赵文华等.应用等离子体净化尾气中NO的研究[J].环境污染治理技术与设备, May 2002. Vol.3,No.5
[20]王喜眉等.介质阻挡放电净化汽车尾气中CO的实验研究[J].山西科技, 2005年第一期.
[21] Jae-Duk Moon, Geun-Taek Lee. SO2 and CO Gas Removal and Discharge Characteristics of a Nonthermal Plasma Reactor in a Crossed DC Magnetic Field[J]. IEEE Transactions on Industrv Amlications, Vol. 29, No. 4, pp.781-786, 1993.
[22]张春润等.介质阻挡放电净化汽车尾气NOX和HC的应用研究[J].高技术通讯, 2004.3.
[23]蒋洁敏等.非平衡态等离子体作用下一氧化碳的转化[J].化学世界, 2002年增刊.
[24] Masaaki Okubo, Member. NOX Reduction Aftertreatment System Using Nitrogen Nonthermal Plasma Desorption, NOX Reduction Aftertreatment System Using Nitrogen Nonthermal Plasma Desorption[J]. IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS, VOL.41, NO.4, JULY/AUGUST 2005.
[25]叶丽华等.低温等离子体净化汽车尾气中NO的试验研究[J].农业装备技术, Dec.2004, Vol.30 No.6.
[26]徐卡秋.等离子体改性燃油对汽车尾气中NO生成的抑制作用[J].四川大学学报(自然科学版), Aug.2005, Vol.42 No.4.
[27] B.S.Rajanikanth. Unfiltered Diesel Engine Exhaust Treatment by Discharge Plasma: Effect of Soot Oxidation[J]. Plasma science &Technology,Vol.6,No.5,Oct 2004.
[28]曾科等.采用低温等离子体技术降低柴油机有害排放物的研究[J].内燃机学报, Vol.21(2003)No.1.
[29] B.S.Rajanikanth. A Cascaded Discharge Plasma-Adsorbent Technique for Engine Exhaust Treatment[J]. Plasma science &Technology,Vol.5,No.3(2003)
[30]许洪军.柴油机尾气氮氧化物的机外净化技术研究[J].内燃机, No.6 Dec.2004.
[31]王燕等. DBD等离子体及其应用技术的发展[J].自然杂志, Vol.24 No.5.
[32] V.Ravi, Young Sun Mok. Studies on Nitrogen Oxides Removal Using Plasma Assisted Catalytic Reactor[J]. Plasma science &Technology,Vol.5,No.6(2003).
[33]张仁熙.等离子体技术在环境保护中的应用[J].环境保护, 2000年第20期.
[34] Koichi Takaki, Tamiya Fujiwara. Multipoint Barrier Discharge Process for Removal of NOX from Diesel Engine Exhaust[J]. IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 29, NO. 3, JUNE 2001.
[35]都基峻.低温等离子体处理气态污染物[J].污染防治技术, Mar 2000, Vol.13 No.6.
[36]杨武.低温等离子体空气净化原理及应用[J].电工技术杂志, 2003年第3期.