掺烧甲醇发动机甲醛排放特性的研究
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摘要
作为汽车的代用燃料,甲醇由于生产成本低,生产技术成熟等原因在我国有着广泛的应用前景,但是甲醇燃料的使用会使发动机尾气中甲醛排放增多。甲醛是较高毒性的物质,对人体和大气环境都存在危害。因此,了解与掌握内燃机尾气中的醛类排放特性,对控制甲醛排放、推广醇类燃料的推广使用具有重要意义。
本课题采用酸性条件下的2,4-二硝基苯肼吸收尾气中的甲醛,生成甲醛腙,利用气相色谱仪分析出甲醛腙的含量,经过计算从而最终得出尾气中甲醛的含量。基于此原理建立了一套内燃机尾气甲醛检测装置,并根据大量实验结果对比,确定了采样系统以及色谱的参数。
利用此检测装置和方法本课题着重研究了柴油/甲醇组合燃烧方式(diesel/methanol compound combustion, DMCC)和掺甲醇汽油尾气中甲醛排放规律,通过大量试验对比,发现发动机负荷、甲醇替代率、喷射方式、催化转化器、排气温度对尾气中甲醛排放都存在影响。
研究结果表明: DMCC燃烧方式的尾气中甲醛排放浓度是原机的10～30倍;在相同转速和相同甲醇替代率时,低负荷下甲醛排放最高,中负荷时甲醛排放最少,高负荷时甲醛排放居中;在中低负荷时,随着甲醇替代率的升高,甲醛生成量呈现递增趋势。在高负荷高甲醇替代率时,甲醛排放则略有下降;相同工况点,顺序喷射的尾气中甲醛含量要低于连续喷射;催化转化器对尾气中甲醛的消除效果与排气温度有很大关系。当排气温度低于300℃或高于410℃时,催化后甲醛会减少;当排气温度300℃ 对汽油机燃用93#汽油与不同甲醇汽油配比燃料(M10、M20和M30)时的醛类排放进行了对比分析,结果表明:与燃用纯汽油相比,掺烧甲醇时尾气中的甲醛排放明显增加。M10、M20可以达到M0的2倍,而M30增加幅度最大,可以达到M0的近7倍;三效催化转化器可以很好地消除尾气中甲醛排放,经过催化处理后,不同汽油甲醇配比燃料的甲醛排放均明显降低,都可以被控制在接近零排放的水平。
Methanol as alternative fuel for vehicles has a broad prospect in China because of its low producing cost and formed production technique. However, Formaldehyde emission of engine powered by methanol is known for strong carcinogenicity,and it can harm atmospheric environment and human health.Hence,generalize the methanol fuel so as to controlling the emission concentration of aldehyde is of great significance.
A method is provided to determinate formaldehyde in the engine exhaust: Formaldehyde is absorbed by the acidic saturated solution of 2,4-dinitrophenyl hydrazine (DNPH) and converted to its hydrazone, the hydrazone is then extracted with CS2 and determinated using Gas Chromatography (GC). Based on theory mentioned above ,a sampling system is designed to measure formaldehyde emitted from engine.
The measure method is applied to determine the formaldehyde emission from a DMCC engine, It is revealed by experiments that load、methanol proportion、methanol injection styles、catalytic converter、exhaust temperature affect formaldehyde emission characteristic from DMCC engine.
The results showed as follows: the formaldehyde concentration from DMCC engine is about 10～30 times higher than that of diesel engine; the formaldehyde concentration is the highest at low-load, the lowest at medium-load at same rotate speed and methanol proportion; with the increasing of methanol proportion, the formaldehyde in exhaust is increasing in low load and middle load; the formaldehyde emission of Sequential Fuel Injection mode is less than that of Continuous Fuel Injection style at same work condition; the exhaust temperature is a key factor for the catalytic converter’s effect. When the exhaust temperature is lower than 300℃or higher than 410℃, the formaldehyde emission is decreased by the catalyst, but it would increased if the exhaust temperature between 300℃to 410℃.
Besides, this measure method determine the formaldehyde emission from a gasoline engine powered by M0、M10、M20、M30,respectively. The results showed as follows: the formaldehyde concentration of methanol/gasoline engine is 2~7 times higher than that of gasoline engine, but it is decreased by catalytic converter obviously to approach ultra-low emission.
本课题采用酸性条件下的2,4-二硝基苯肼吸收尾气中的甲醛,生成甲醛腙,利用气相色谱仪分析出甲醛腙的含量,经过计算从而最终得出尾气中甲醛的含量。基于此原理建立了一套内燃机尾气甲醛检测装置,并根据大量实验结果对比,确定了采样系统以及色谱的参数。
利用此检测装置和方法本课题着重研究了柴油/甲醇组合燃烧方式(diesel/methanol compound combustion, DMCC)和掺甲醇汽油尾气中甲醛排放规律,通过大量试验对比,发现发动机负荷、甲醇替代率、喷射方式、催化转化器、排气温度对尾气中甲醛排放都存在影响。
研究结果表明: DMCC燃烧方式的尾气中甲醛排放浓度是原机的10～30倍;在相同转速和相同甲醇替代率时,低负荷下甲醛排放最高,中负荷时甲醛排放最少,高负荷时甲醛排放居中;在中低负荷时,随着甲醇替代率的升高,甲醛生成量呈现递增趋势。在高负荷高甲醇替代率时,甲醛排放则略有下降;相同工况点,顺序喷射的尾气中甲醛含量要低于连续喷射;催化转化器对尾气中甲醛的消除效果与排气温度有很大关系。当排气温度低于300℃或高于410℃时,催化后甲醛会减少;当排气温度300℃
Methanol as alternative fuel for vehicles has a broad prospect in China because of its low producing cost and formed production technique. However, Formaldehyde emission of engine powered by methanol is known for strong carcinogenicity,and it can harm atmospheric environment and human health.Hence,generalize the methanol fuel so as to controlling the emission concentration of aldehyde is of great significance.
A method is provided to determinate formaldehyde in the engine exhaust: Formaldehyde is absorbed by the acidic saturated solution of 2,4-dinitrophenyl hydrazine (DNPH) and converted to its hydrazone, the hydrazone is then extracted with CS2 and determinated using Gas Chromatography (GC). Based on theory mentioned above ,a sampling system is designed to measure formaldehyde emitted from engine.
The measure method is applied to determine the formaldehyde emission from a DMCC engine, It is revealed by experiments that load、methanol proportion、methanol injection styles、catalytic converter、exhaust temperature affect formaldehyde emission characteristic from DMCC engine.
The results showed as follows: the formaldehyde concentration from DMCC engine is about 10～30 times higher than that of diesel engine; the formaldehyde concentration is the highest at low-load, the lowest at medium-load at same rotate speed and methanol proportion; with the increasing of methanol proportion, the formaldehyde in exhaust is increasing in low load and middle load; the formaldehyde emission of Sequential Fuel Injection mode is less than that of Continuous Fuel Injection style at same work condition; the exhaust temperature is a key factor for the catalytic converter’s effect. When the exhaust temperature is lower than 300℃or higher than 410℃, the formaldehyde emission is decreased by the catalyst, but it would increased if the exhaust temperature between 300℃to 410℃.
Besides, this measure method determine the formaldehyde emission from a gasoline engine powered by M0、M10、M20、M30,respectively. The results showed as follows: the formaldehyde concentration of methanol/gasoline engine is 2~7 times higher than that of gasoline engine, but it is decreased by catalytic converter obviously to approach ultra-low emission.
引文
[1]全国工商联石油商会网,8月1日国内成品油市场简报,2007,http://www.cccpi.org
[2]全国工商联石油商会网,2007-2008年国际油价走势回顾与展望, 2007,http://www.cccpi.org
[3]调研在线,2008年中国汽车需求量相当于目前全球需求1/4, 2008, http://www.mrpad.com
[4]李志东,中国的能源和环境问题,经济管理文摘,2005,(5):43～43,45
[5]王欲进,发动机代用燃料的发展探索,太原大学学报,2007,8(2):125～127
[6]周玉明,内燃机代用燃料(一),内燃机,2002,(6):40～41
[7]周玉明,内燃机代用燃料(二),内燃机,2003,(1):37～39
[8]金琳,我国煤制油发展现状趋势及建议,油气世界,2007,(3):1～4
[9]陈福强,醇类燃料在车用发动机上的研究现状,甘肃科技纵横,2006,35(2):43～44
[10]任继文,吴建全,李建新等,发展我国车用甲醇发动机的实践与思考,车用发动机,2003(3):1～5
[11]何学良,李疏松,詹永厚,内燃机燃料,北京:中国石化出版社,1999
[12]王丹,朱向荣,车用代用燃料研究及发展趋势,汽车工艺与材料,2005,(10):1～5
[13]陈杰,二甲醚-内燃机代用燃料,内蒙古石油化工,2007,(7):57～58
[14]王涛,生态能源林未来生物质燃料油原料基地,绿色中国:中国版,2007,(3):30～33
[15]王翔,郭拥军,张建军,甲醇、汽油及甲醇汽油作内燃机燃料的性质比较,化工时刊,2005,19(3):46～49
[16]谢洁,王锡斌,卢红兵等,柴油-甲醇微乳化燃料的制备及燃烧特性研究,内燃机工程,2004,25(2):1～5
[17]刘永启,王延遐,罗远荣,柴油-甲醇-水复合乳化燃料的试验研究,山东内燃机,2001,(3):23~27
[18]傅茂林,李海林,谭从民等,柴油-甲醇-水复合乳化燃料喷雾特性的研究,内燃机学报,1995,13(4):409~413
[19] Shi Shaoxi,Fu Maolin,Yang Jingyun,et al,Study on Burning Pure Methanol in DI Diesel Engines by Hot-Surface Ignition,内燃机学报,1994,(3)
[20]宫长明,刘金山,徐百龙等,火花助燃甲醇发动机燃烧特性研究,内燃机学报,1998,16(1):31～36
[21]姚春德,程传辉,段峰等,柴油/甲醇组合燃烧对废气涡轮增压柴油机排放的影响研究,内燃机学报,2005,23(2):121～123
[22]韩志玉,周龙保,吕萍等,火花助燃柴油机应用醇类燃料时的工作稳定性和放热特性,西安交通大学学报,1992,26(2):15～22
[23]孙志远,王树奎,傅茂林等,采用电热塞助燃法在原压燃式发动机中燃用甲醇的实验研究,内燃机学报,1995,12(4):352～359
[24] Cribb, P.H., Dove, J.E.,Yamazaki, S.A Kinetic Study of the Oxidation of Methanol Using shock tube and computer simulation techniques, Combustion and Flame,1992,88 (2):186～200
[25]李晖,刘圣华,周龙保,柴油机燃用甲醇的应用研究和进展,内燃机,2004,(5):1～3
[26]姚春德,李云强,甲醇燃料在柴油机中的应用与发展,小型内燃机与摩托车,2004,33(1):37～40
[27]姚春德,程传辉,段峰等,柴油/甲醇组合燃烧对废气涡轮增压柴油机排放的影响研究,内燃机学报,2005,23(2):121～123
[28] Yao C D,Cheung C S, Cheng C H,Wang Y S,Reduction of smoke and NOx from diesel engines using a diesel/methanol compound combustion system,Energy Fuels,2007, 21(2):686~691
[29]《化工百科全书》编辑部,化工百科全书(第8卷),北京:化学工业出版社,1994,229～236
[30]王美美,范璐,吴娜娜等,不同样品中甲醛含量的测定方法综述,河南工业大学学报,2007,28(4):84～88
[31]陈韶,室内环境中的甲醛污染,家具与室内装饰,2006,(7):46～47
[32]彭万喜,许少宏,张仲凤等,世界各国对甲醛释放量的限制,家具与室内装饰,2007,(9):32～33
[33]黄智勇,张剑,室内空气中甲醛测定方法研究现状,中国公共卫生,2006,22(2):231～233
[34] C.Hak,I.Pundt,S.Trick.Intercomparison of four different in-situtechniques for ambient formaldehyde measurements in urban air, Atmos. Chem. Phys. Discuss, 2005,5:2897-2945
[35] Kato S, Miyakawa Y, Kaneko T, et a1, Urban air measurements using PTR-MS in Tokyo area and comparison with GC-FID easurements, International Journal of Mass Spectrometry, 2004, 235(2): 103～110
[36] Gouw J, Goldan P, Warneke C,et a1, Validation of proton transfer reaction-mass spectrometry (PTR-MS) measurements of gas-phase organic compounds in the atmosphere during the New England Air Quality Study (NEAQS)in 2002, Journal of Geophysical Research-Atmospheres, 2003,108(D21): 4682
[37] Kuster W, Jobson B,Karl T, et a1, Intercomparison of volatile organic carbon measurement techniques and data at a porte during the TexAQS2000 Air Quality Study, Environmental Science &Technology, 2004, 38(1):221～228
[38] Jobson B T, Alexander M L, Maupin G D, et al, On-line analysis of organic compounds in diesel exhaust using a proton transfer reaction mass spectrometer(PTR-MS). International Jouenal of Mass Spectrometry 2005, 245(1-3): 78~89
[39]中华人民共和国国家技术监督局,GB/T15516-1995,空气质量甲醛的测定乙酰丙酮分光光度法,北京:中国标准出版社,1995-03-15
[40]杨素珊,分光光度法测定空气中甲醛的研究,广东建材,2006(7):103～105
[41]曹蕾,两种分光光度法测定空气中甲醛的比较,口岸卫生控制,2000,8(5):10～11
[42]张志虎,邵华,甲醛及其检测方法的研究进展,中国职业医学,2005,32(1):55～57
[43]柏林洋,李方实,微量甲醛检测方法的研究进展,化工时刊,2005,19(5):58～61
[44]中华人民共和国卫生部、国家环境保护总局,GB/T 18204.26-2000,公共场所空气中甲醛测定方法,北京:中国标准出版社,2000
[45]刘剑平、孙惠、马继勇,气相色谱法测定白酒中微量醛,中国卫生检验杂志,2005,15(3):324～325
[46]刘义亭,柴油/甲醇组合燃烧方式甲醛排放特性的研究:[硕士学位论文],天津:天津大学,2007年6月
[47] Pop Alexandra,et al.Oxidation of methanol to formaldehyde on Fe—Mo oxide catalysts[J].Rev Chim,1997,48(7):616～620
[48]李晓秀,徐金利,周萍,影响甲醇-甲醛转化率的因素及控制方法,林业技术,2001,26(4):48～49
[49]高国珍,王育辉,陈光敏,醇类燃料理化性质对汽油机性能及排放的影响,江西能源,2004,(3):8-10,20
[50]祁东辉,刘圣华,李晖等,电喷汽油机燃用甲醇一汽油混合燃料的性能,交通运输工程学报,2006,6(2):43～46
[51]崔心存,未燃甲醇、甲醛的生成机理及其控制措施,山西醇醚燃料网,http://www.alcohol-ether.cn
[2]全国工商联石油商会网,2007-2008年国际油价走势回顾与展望, 2007,http://www.cccpi.org
[3]调研在线,2008年中国汽车需求量相当于目前全球需求1/4, 2008, http://www.mrpad.com
[4]李志东,中国的能源和环境问题,经济管理文摘,2005,(5):43～43,45
[5]王欲进,发动机代用燃料的发展探索,太原大学学报,2007,8(2):125～127
[6]周玉明,内燃机代用燃料(一),内燃机,2002,(6):40～41
[7]周玉明,内燃机代用燃料(二),内燃机,2003,(1):37～39
[8]金琳,我国煤制油发展现状趋势及建议,油气世界,2007,(3):1～4
[9]陈福强,醇类燃料在车用发动机上的研究现状,甘肃科技纵横,2006,35(2):43～44
[10]任继文,吴建全,李建新等,发展我国车用甲醇发动机的实践与思考,车用发动机,2003(3):1～5
[11]何学良,李疏松,詹永厚,内燃机燃料,北京:中国石化出版社,1999
[12]王丹,朱向荣,车用代用燃料研究及发展趋势,汽车工艺与材料,2005,(10):1～5
[13]陈杰,二甲醚-内燃机代用燃料,内蒙古石油化工,2007,(7):57～58
[14]王涛,生态能源林未来生物质燃料油原料基地,绿色中国:中国版,2007,(3):30～33
[15]王翔,郭拥军,张建军,甲醇、汽油及甲醇汽油作内燃机燃料的性质比较,化工时刊,2005,19(3):46～49
[16]谢洁,王锡斌,卢红兵等,柴油-甲醇微乳化燃料的制备及燃烧特性研究,内燃机工程,2004,25(2):1～5
[17]刘永启,王延遐,罗远荣,柴油-甲醇-水复合乳化燃料的试验研究,山东内燃机,2001,(3):23~27
[18]傅茂林,李海林,谭从民等,柴油-甲醇-水复合乳化燃料喷雾特性的研究,内燃机学报,1995,13(4):409~413
[19] Shi Shaoxi,Fu Maolin,Yang Jingyun,et al,Study on Burning Pure Methanol in DI Diesel Engines by Hot-Surface Ignition,内燃机学报,1994,(3)
[20]宫长明,刘金山,徐百龙等,火花助燃甲醇发动机燃烧特性研究,内燃机学报,1998,16(1):31～36
[21]姚春德,程传辉,段峰等,柴油/甲醇组合燃烧对废气涡轮增压柴油机排放的影响研究,内燃机学报,2005,23(2):121～123
[22]韩志玉,周龙保,吕萍等,火花助燃柴油机应用醇类燃料时的工作稳定性和放热特性,西安交通大学学报,1992,26(2):15～22
[23]孙志远,王树奎,傅茂林等,采用电热塞助燃法在原压燃式发动机中燃用甲醇的实验研究,内燃机学报,1995,12(4):352～359
[24] Cribb, P.H., Dove, J.E.,Yamazaki, S.A Kinetic Study of the Oxidation of Methanol Using shock tube and computer simulation techniques, Combustion and Flame,1992,88 (2):186～200
[25]李晖,刘圣华,周龙保,柴油机燃用甲醇的应用研究和进展,内燃机,2004,(5):1～3
[26]姚春德,李云强,甲醇燃料在柴油机中的应用与发展,小型内燃机与摩托车,2004,33(1):37～40
[27]姚春德,程传辉,段峰等,柴油/甲醇组合燃烧对废气涡轮增压柴油机排放的影响研究,内燃机学报,2005,23(2):121～123
[28] Yao C D,Cheung C S, Cheng C H,Wang Y S,Reduction of smoke and NOx from diesel engines using a diesel/methanol compound combustion system,Energy Fuels,2007, 21(2):686~691
[29]《化工百科全书》编辑部,化工百科全书(第8卷),北京:化学工业出版社,1994,229～236
[30]王美美,范璐,吴娜娜等,不同样品中甲醛含量的测定方法综述,河南工业大学学报,2007,28(4):84～88
[31]陈韶,室内环境中的甲醛污染,家具与室内装饰,2006,(7):46～47
[32]彭万喜,许少宏,张仲凤等,世界各国对甲醛释放量的限制,家具与室内装饰,2007,(9):32～33
[33]黄智勇,张剑,室内空气中甲醛测定方法研究现状,中国公共卫生,2006,22(2):231～233
[34] C.Hak,I.Pundt,S.Trick.Intercomparison of four different in-situtechniques for ambient formaldehyde measurements in urban air, Atmos. Chem. Phys. Discuss, 2005,5:2897-2945
[35] Kato S, Miyakawa Y, Kaneko T, et a1, Urban air measurements using PTR-MS in Tokyo area and comparison with GC-FID easurements, International Journal of Mass Spectrometry, 2004, 235(2): 103～110
[36] Gouw J, Goldan P, Warneke C,et a1, Validation of proton transfer reaction-mass spectrometry (PTR-MS) measurements of gas-phase organic compounds in the atmosphere during the New England Air Quality Study (NEAQS)in 2002, Journal of Geophysical Research-Atmospheres, 2003,108(D21): 4682
[37] Kuster W, Jobson B,Karl T, et a1, Intercomparison of volatile organic carbon measurement techniques and data at a porte during the TexAQS2000 Air Quality Study, Environmental Science &Technology, 2004, 38(1):221～228
[38] Jobson B T, Alexander M L, Maupin G D, et al, On-line analysis of organic compounds in diesel exhaust using a proton transfer reaction mass spectrometer(PTR-MS). International Jouenal of Mass Spectrometry 2005, 245(1-3): 78~89
[39]中华人民共和国国家技术监督局,GB/T15516-1995,空气质量甲醛的测定乙酰丙酮分光光度法,北京:中国标准出版社,1995-03-15
[40]杨素珊,分光光度法测定空气中甲醛的研究,广东建材,2006(7):103～105
[41]曹蕾,两种分光光度法测定空气中甲醛的比较,口岸卫生控制,2000,8(5):10～11
[42]张志虎,邵华,甲醛及其检测方法的研究进展,中国职业医学,2005,32(1):55～57
[43]柏林洋,李方实,微量甲醛检测方法的研究进展,化工时刊,2005,19(5):58～61
[44]中华人民共和国卫生部、国家环境保护总局,GB/T 18204.26-2000,公共场所空气中甲醛测定方法,北京:中国标准出版社,2000
[45]刘剑平、孙惠、马继勇,气相色谱法测定白酒中微量醛,中国卫生检验杂志,2005,15(3):324～325
[46]刘义亭,柴油/甲醇组合燃烧方式甲醛排放特性的研究:[硕士学位论文],天津:天津大学,2007年6月
[47] Pop Alexandra,et al.Oxidation of methanol to formaldehyde on Fe—Mo oxide catalysts[J].Rev Chim,1997,48(7):616～620
[48]李晓秀,徐金利,周萍,影响甲醇-甲醛转化率的因素及控制方法,林业技术,2001,26(4):48～49
[49]高国珍,王育辉,陈光敏,醇类燃料理化性质对汽油机性能及排放的影响,江西能源,2004,(3):8-10,20
[50]祁东辉,刘圣华,李晖等,电喷汽油机燃用甲醇一汽油混合燃料的性能,交通运输工程学报,2006,6(2):43～46
[51]崔心存,未燃甲醇、甲醛的生成机理及其控制措施,山西醇醚燃料网,http://www.alcohol-ether.cn