检索结果-南通市图书馆

Journal of Environmental Sciences 2024年第2期136卷 35-44页

作者： Yunhua Zhang diming lou Piqiang Tan Zhiyuan Hu Liang Fang School of Automotive Studies Tongji UniversityShanghai 201804China

In this study,the effect of new and used catalyzed diesel particulate filter(CDPF)with different catalyst loadings on the particulate emissions including the particle mass(PM),particle number(PN),particle size distribution(PSD)and geometric mean diameter(GMD)from a diesel vehicle were investigated based on a heavy chassis *** showed that more than 97.9%of the PN and 95.4%of the PM were reduced by the CDPF,and the reduction efficiency was enhanced by the catalyst *** using the CDPF,the PSD transformed from bimodal to trimodal with the peak shifting towards smaller particle size,more nucleation mode particles were reduced compared with accumulation mode ones,but the reduction effect on the accumulation mode particles was more significantly influenced by the catalyst ***,the CDPF increased the accumulation mode particles proportion,producing a larger *** the used CDPF,its reduction effect on the particulate emissions enhanced,especially for the PM in accumulation *** PSD returned to bimodal,but the peak at accumulation mode began to be higher than that at nucleation mode,illustrating that more nucleation mode particles was *** aging of the CDPF resulted in greater effect on the PN-based PSD than that of PM-based PSD,but the effect of catalyst loading on the PN and PM emission factors was *** used CDPF further increased the GMD,and the effect of catalyst loading on the GMD was strengthened,a higher catalyst loading led to a reduction in the GMD.

关键词： Catalyzed diesel particulate filter (CDPF) Catalyst loading Aging Particle Particle size distribution Geometric mean diameter

Influence of Mixture Gas Conditions on the Laminar Combustion Characteristics of Natural Gas

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2024年第3期33卷 1231-1241页

作者： lou diming ZHU Kan ZHANG Yunhua REN Yedi TAN Piqiang FANG Liang FAN Lanlan School of Automotive Studies Tongji UniversityShanghai201804China Ji’nan Power Co.Ltd Sinotruk GroupJi’nan250200China

Natural gas is a promising alternative fuel for the internal combustion engine,and natural gas engine has become an efficient and feasible measure to deal with the energy shortage and climate *** the laminar flame characteristics are the foundation of the turbulent flame,the laminar flame characteristics of natural gas have a significant impact on the combustion status and efficiency of the engine.A visual constant volume bomb was used to study the influence of the gas components,different excess air coefficient(λ),and initial conditions on the laminar combustion characteristics of natural *** experimental results showed that when the initial pressure and temperature were 0.1 MPa and 300 K respectively,compared to propane,ethane had a remarkable influence on the equivalent-combustion laminar-combustion-speed,with an average increase of approximately 5.1%for every 2.5%increase in the ethane *** laminar combustion velocity of the natural gas under different excess air coefficients had a maximum value at aboutλ=1.0,and the Markstein length of the flame decreased with the increase of theλ.The increase in the initial pressure of the mixture resulted in a decrease in the equivalent-combustion laminar-combustion-speed of the flame,a significant decrease in the Markstein *** increase of the initial temperature of the mixture led to a rapid increase of the equivalent-combustion laminar-combustion-speed,but the effect on the flame Markstein length was not dominant.

关键词： constant volume bomb natural gas engine combustion characteristics laminar combustion velocity Markstein length

La_(2)O_(3)掺杂对CDPF老化性能的影响

在线全文

学校读者我要写书评

暂无评论

稀有金属材料与工程 2024年第4期53卷 1032-1041页

作者：张允华郑森楼狄明房亮冯谦同济大学汽车学院上海201804 北京市生态环境监测中心北京100044

基于XRD、XPS、H_(2)-TPR等表征方法以及活性评价方法,研究了不同浓度La_(2)O_(3)掺杂CDPF样品水热老化状态下的理化特性与催化活性。结果表明:随着La_(2)O_(3)掺杂浓度增加,CDPF老化样品衍射特征峰位向大角度偏移程度以及结晶度均呈先... 详细信息

基于XRD、XPS、H_(2)-TPR等表征方法以及活性评价方法,研究了不同浓度La_(2)O_(3)掺杂CDPF样品水热老化状态下的理化特性与催化活性。结果表明:随着La_(2)O_(3)掺杂浓度增加,CDPF老化样品衍射特征峰位向大角度偏移程度以及结晶度均呈先降低后增加的趋势。La_(2)O_(3)掺杂能够较好地抑制样品在高温水热老化过程中的烧结和畸变,并且可以有效抑制活性位数量的减少,使CDPF表面Pt原子浓度基本保持不变,对CO、C_(3)H_(8)和NO催化性能的劣化率降低,并且随掺杂浓度的增大,CDPF抗老化性能有增强的趋势。

关键词： CDPF催化剂 La_(2)O_(3) 理化特性催化活性劣化性能

在线全文

学校读者我要写书评

暂无评论

双金属氧化物掺杂对CDPF老化性能的影响

稀有金属材料与工程 2024年第5期53卷 1391-1400页

作者：张允华郑森楼狄明房亮冯谦同济大学汽车学院上海201804 北京市生态环境监测中心北京100044

基于XRD、XPS、H_(2)-TPR等理化特性表征方法与催化剂活性评价方法,研究了掺杂不同双金属氧化物催化型柴油机颗粒捕集器(CDPF)样品水热老化状态下的理化特性与催化活性。结果表明:掺杂Ce-Zr双金属氧化物的CDPF样品物相结构和晶胞参数稳... 详细信息

基于XRD、XPS、H_(2)-TPR等理化特性表征方法与催化剂活性评价方法,研究了掺杂不同双金属氧化物催化型柴油机颗粒捕集器(CDPF)样品水热老化状态下的理化特性与催化活性。结果表明:掺杂Ce-Zr双金属氧化物的CDPF样品物相结构和晶胞参数稳定性较好,掺杂Zr-Fe双金属氧化物的CDPF样品能较好地抑制老化后载体表面贵金属分散度的降低程度。掺杂Fe-Ce和Zr-Fe的CDPF样品在高温老化过程中分散的金属氧化物会再次发生固溶而形成较多的固溶体,带来更多氧空位。经历高温水热老化后,CDPF样品的还原峰均不同程度地向高温方向迁移,其中掺杂Fe-Ce的CDPF样品还原峰迁移幅度较低,掺杂Ce-Zr的CDPF样品还原峰迁移幅度较大。掺杂Fe-Ce和Zr-Fe的CDPF样品老化后对CO的氧化活性较高,劣化程度较小,并且保持较好的NO催化选择性。掺杂Ce-Zr的CDPF样品老化后对C3H8氧化活性略有下降。

关键词：双金属氧化物催化型柴油机颗粒捕集器理化特性催化活性老化性能

国Ⅵ直喷汽油机颗粒数量及微观形貌排气输运演变特性

在线全文

学校读者我要写书评

暂无评论

同济大学学报（自然科学版） 2024年第4期52卷 628-636页

作者：胡志远高鑫舜陆张颖谭丕强楼狄明同济大学汽车学院上海201800

开展了某一国Ⅵ直喷汽油机三元催化转化器(TWC)前、TWC后、汽油机颗粒捕集器(GPF)后3个位置的颗粒物采样及微观形貌研究,分析了发动机工况、TWC、GPF对国Ⅵ直喷汽油机尾气颗粒数量、粒径分布、微观形貌的影响。结果表明,该直喷汽油机尾... 详细信息

开展了某一国Ⅵ直喷汽油机三元催化转化器(TWC)前、TWC后、汽油机颗粒捕集器(GPF)后3个位置的颗粒物采样及微观形貌研究,分析了发动机工况、TWC、GPF对国Ⅵ直喷汽油机尾气颗粒数量、粒径分布、微观形貌的影响。结果表明,该直喷汽油机尾气颗粒数量排放整体上呈单峰分布,低转速小负荷工况下,粒径<23nm的颗粒数量较高。随着发动机转速和负荷的增大,峰值粒径向大粒径方向移动。直喷汽油机尾气颗粒物由“核‒壳”结构基本碳粒子堆积形成,呈链状、枝状、簇状等结构;负荷增大,颗粒物尺寸略有增大,基本碳粒子重叠度增强,分形维数增大;转速增大,颗粒物尺寸减小,基本碳粒子重叠度减弱,分形维数减小。随着排气输运的进行,颗粒数量逐渐降低;TWC不影响颗粒的粒径分布形态,颗粒数量净化效率41.6%~94.2%,对<23 nm的小粒径颗粒净化效果较好,低转速小负荷工况的颗粒数量净化效率较高;GPF的颗粒数量净化效率约80%,23~100 nm颗粒数量净化效率较高,对粒径<10nm的颗粒净化作用不大。TWC和GPF不影响颗粒物结构形式,TWC和GPF后颗粒物基本碳粒子重叠度减弱,分形维数减小。

关键词：直喷汽油机颗粒物数量微观形貌排气输运

Effect of catalyzed diesel particulate filter and its catalyst loading on emission characteristics of a non-road diesel engine

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2023年第4期126卷 794-805页

作者： Yunhua Zhang diming lou Piqiang Tan Zhiyuan Hu Liang Fang School of Automotive studies Tongji UniversityShanghai 201804China

In this study, the effects of a diesel oxidation catalyst(DOC) coupled with a catalyzed diesel particulate filter(CDPF) with different catalyst loadings on the power, fuel consumption,gaseous and particulate emissions from a non-road diesel engine were investigated. Results showed that the after-treatment had a negligible effect on the power and fuel *** reduction effect of the DOC on the CO and hydrocarbon(HC) increased with the engine load. Further reductions occurred coupling with the CDPF. Increasing the catalyst loading resulted in a more significant reduction in the HC emissions than CO emissions. The DOC could increase the NO_(2)proportion to 37.9%, and more NO_(2)was produced when coupled with the CDPF below 250℃;above 250℃, more NO_(2)was consumed. The after-treatment could reduce more than 99% of the particle number(PN) and 98% of the particle mass(PM).Further reductions in the PN and PM occurred with a higher CDPF catalyst loading. The DOC had a better reduction effect on the nucleation particles than the accumulation ones, but the trend reversed with the CDPF. The DOC shifted the particle size distribution(PSD) to larger particles with an accumulation particle proportion increasing from 13% to 20%, and the geometric mean diameter(GMD) increased from 18.2 to 26.0 nm. The trend reversed with the CDPF and the accumulation particle proportion declined to less than 10%. A lower catalyst loading on the CDPF led to a higher proportion of nucleation particles and a smaller GMD.

关键词： Catalyzed diesel particulate filter Catalyst loading Emissions Particle size distribution Geometric mean diameter

Selective catalytic reduction failure of low NH_(3)-NO_(x) ratio

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2021年第4期34卷 231-240页

作者： Piqiang Tan Xiaoyu Li Shiyan Wang Zhiyuan Hu diming lou School of Automobile Studies Tongji UniversityShanghai 201804China

An insufficient amount of NH_(3) (ammonia)will reduce the conversion efficiency of NO_(x),which may lead to excess NO_(x) emissions,resulting in NH3SCR *** this article,SCR failure caused by a low NH_(3)NO_(x) ratio is studied systematically by *** main reasons for a low NH_(3)NO_(x) ratio in SCR include insufficient urea injection,hydrothermal aging of catalysts and urea *** was found from an insufficient urea injection experiment that with the increase of NH_(3)NO_(x) ratio,the NO_(x) conversion efficiency of the SCR system increased,but the ammonia leakage also *** main influencing factors of NO_(x) conversion efficiency are different under different NH3NOx ratios.A flow reactor system was used in the catalyst hydrothermal aging experiment to investigate the effect of hydrothermal aging on catalyst *** a 24 h hydrothermal aging experiment at 800℃,the NO_(x) conversion efficiency of the copperbased zeolite catalysts decreased significantly at the boundary of medium and low temperature *** the NO_(2)-NO_(x) ratio in the mixture had a significant effect on the catalytic *** coupled to Fourier transform infrared spectroscopy(TGFTIR)was used to analyze the composition of urea deposits in a urea deposits analysis *** was found that the main components of urea deposits were urea and isocyanic acid(HNCO).Preventing HNCO polymerization,especially the formation of CYA,can decrease the formation of urea deposits.

关键词： SCR Low NH_(3)-NO_(x)ratio Purification Hydrothermal Urea crystallization

Emission reduction characteristics of a catalyzed continuously regenerating trap after-treatment system and its durability performance

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2019年第10期31卷 166-173页

作者： Yunhua Zhang diming lou Piqiang Tan Zhiyuan Hu Hu Li School of Automotive studies Tongji University Shanghai 201804 China School of Chemical and Process Engineering Faculty of Engineering University of Leeds Leeds LS2 9JT UK

The primary purpose of this study was to investigate the effect of a catalyzed continuously regenerating trap(CCRT)system composed of a diesel oxidation catalyst(DOC)and a catalyzed diesel particulate filter(CDPF)on the main gaseous and particulate emissions from an urban diesel bus,as well as the durability performance of the CCRT *** were conducted based on a heavy chassis dynamometer,and a laboratory activity test as well as X-ray photoelectron spectroscopy(XPS)test were applied to evaluate the changes of the aged CCRT *** showed that the CCRT could reduce the CO by 71.5%and the total hydrocarbons(THC)by 88.9%,and meanwhile promote the oxidation of ***,the conversion rates for CO and THC dropped to 25.1%and 55.1%,respectively,after the CCRT was used for one year(~60,000 km),and the NO oxidation was also *** particulate emissions,the CCRT could reduce 97.4%of the particle mass(PM)and almost 100%of the particle number(PN).The aging of the CCRT resulted in a reduced PM trapping efficiency but had no observable effect on the PN;however,it increased the proportion of nucleation mode *** activity test results indicated that the deterioration of the CCRT was directly relevant to the increase in the light-off temperatures of the catalyst for CO,C3H8 and *** addition,the decreased concentrations of the active components Pt2+ and Pt4+ in the catalyst are also important factors in the CCRT deterioration.

关键词： Diesel bus Catalyzed continuously regenerating trap(CCRT) Emissions Durability Deterioration

掺杂La_(2)O_(3)对CDPF催化性能的影响

在线全文

学校读者我要写书评

暂无评论

稀有金属材料与工程 2022年第12期51卷 4689-4696页

作者：楼狄明楼国康张允华房亮冯谦同济大学汽车学院上海201800 北京市生态环境监测中心北京100089

在CDPF催化剂上,通过掺杂浓度10、20和30g/L的La_(2)O_(3)的助剂制备了不同的CDPF样品,采用XRD、XPS、H2-TPR等表征方法以及活性评价技术,研究掺杂不同浓度La_(2)O_(3)的CDPF载体表面催化剂的理化特性和催化活性的关系。结果表明:随着La... 详细信息

在CDPF催化剂上,通过掺杂浓度10、20和30g/L的La_(2)O_(3)的助剂制备了不同的CDPF样品,采用XRD、XPS、H2-TPR等表征方法以及活性评价技术,研究掺杂不同浓度La_(2)O_(3)的CDPF载体表面催化剂的理化特性和催化活性的关系。结果表明:随着La_(2)O_(3)的掺杂浓度的增加,样品的结晶度先增大再减小;样品表面的Pt原子浓度先降低再升高;样品对CO的氧化活性呈下降趋势;样品对C_(3)H_(8)的特征温度T_(10)和T_(50)均呈先增加再降低,然后再增加的趋势;样品对NO_(2)产率的T_(10)呈增加趋势。

关键词： CDPF催化剂 La_(2)O_(3) 理化特性催化活性

在线全文

学校读者我要写书评

暂无评论

国Ⅵ柴油机颗粒数量与微观形貌排气输运演变

华中科技大学学报（自然科学版） 2023年第10期51卷 94-99页

作者：胡志远王世茂谭丕强楼狄明同济大学汽车学院上海201804

为研究柴油机氧化型催化器(DOC)+催化型柴油机颗粒捕集器(CDPF)+选择性催化还原转化器(SCR)+氨逃逸催化器(ASC)后处理系统对国Ⅵ柴油机排气颗粒输运演变的影响,利用发动机粒径谱仪(EEPS)和透射电子显微镜(TEM)对排气颗粒数量、粒径分布... 详细信息

为研究柴油机氧化型催化器(DOC)+催化型柴油机颗粒捕集器(CDPF)+选择性催化还原转化器(SCR)+氨逃逸催化器(ASC)后处理系统对国Ⅵ柴油机排气颗粒输运演变的影响,利用发动机粒径谱仪(EEPS)和透射电子显微镜(TEM)对排气颗粒数量、粒径分布、微观形貌进行了研究.结果表明:国Ⅵ柴油机DOC前的排气颗粒数量较高,呈单峰分布形态,峰值粒径为25~70 nm;随着排气输运的进行,DOC+CDPF后颗粒数量降低约99%,粒径分布形态转变为双峰分布,在6 nm和80~165 nm处出现两个峰值,且颗粒物团簇程度下降,分形维数减小;SCR+ASC后粒径小于12 nm的颗粒数量明显降低,12~50 nm颗粒数量增加,粒径分布保持双峰分布形态,核模态颗粒的峰值粒径增大.

关键词：柴油机颗粒数量粒径分布微观形貌排气输运演变