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1.
基于MOUDI采样装置的186FA柴油机微粒物粒径分布特性研究 总被引:1,自引:0,他引:1
利用微孔沉积式碰撞采集器(MOUDI)进行了非道路用186FA柴油机排气微粒的采集和排气微粒物质量浓度粒径分布特性研究。研究发现:中高负荷工况下,柴油机排气微粒质量浓度粒径分布呈现近似的对数正态分布特性,而且随着负荷增大峰值粒径向小粒径方向偏移;各粒径级微粒质量浓度随负荷的增大而增大,中高负荷时增大趋势显著;积聚模态及粗粒子模态微粒质量浓度随烟度的增大均有增大的趋势,积聚模态微粒增大趋势相对明显;同一负荷率条件下,积聚模态微粒质量浓度基本随转速的升高而降低;中高负荷时微粒质量平均直径在0.32~0.56μm之间,低负荷时向大粒径级方向发展。 相似文献
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《汽车安全与节能学报》2014,(3)
试验研究了缸内直喷(GDI)汽油机的负荷、过量空气系数、点火时刻等参数对于三效催化器(TWC)后的颗粒(PM)排放特性的影响。试验在在2台GDI汽油机上进行,用气相质谱-色谱(GC-MS)联用方法,分析了TWC后微粒中可溶有机成分(SOF)。结果表明:随着负荷增加,微粒质量和数量排放增加,在满负荷工况下,微粒排放大幅增加;TWC后的SOF和核态微粒数量明显降低;随着过量空气系数的增加和点火时刻的推迟,微粒排放呈减少趋势;核态粒径峰值为10~20 nm,积聚态粒径峰值为50~70 nm。负荷、过量空气系数和点火提前角等参数和TWC对微粒粒径范围的影响小。 相似文献
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对高压共轨柴油机稳态与瞬态工况下的微粒排放粒度分布进行了实验研究。结果表明,高压共轨柴油机排气微粒粒径大部分处于250nm以内,超细微粒占绝大多数。稳态工况下,随负荷增加微粒数量浓度分布曲线峰值逐渐向大粒径方向移动,大负荷工况下峰值开始进入积聚态区域。在瞬态工况下,微粒粒度分布曲线呈单峰形态,平均数量浓度分布峰值位于核态区域,峰值区间为15~25nm。在同一负荷(当量比0.5)下,稳态工况的核态微粒的数量、表面积和体积浓度均较稳态工况大幅度上升;随着瞬变率的增大,核态微粒数量浓度增加而积聚态微粒数量浓度下降。 相似文献
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GDI与PFI汽油车微粒排放特性的试验研究 总被引:1,自引:0,他引:1
对3辆缸内直喷(GDI)汽车和1辆进气道燃油喷射(PFI)汽车进行了试验研究,在NEDC循环上采用PMP方法测量微粒质量排放和微粒数量排放,用DMS500型快速微粒分析仪测量微粒瞬态数量排放和粒径分布。结果表明:4辆试验车的微粒质量排放均达到欧Ⅵ法规要求,但GDI汽车的微粒排放远超出法规限值;GDI汽车和PFI汽车在冷起动暖机阶段均有大量微粒生成,GDI汽车在暖机后的瞬态工况会有明显的微粒排放;GDI汽车核态微粒峰值粒径约为18nm,而作为数量排放主要形态的积聚态峰值粒径约为80nm;PFI汽车的积聚态峰值粒径约为60nm,而作为其数量排放主要形态的核态微粒峰值粒径约为12nm。 相似文献
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燃料特性对柴油机排放微粒粒度分布的影响 总被引:2,自引:0,他引:2
利用微粒粒径分析仪进行测试,以研究不同理化特性的燃料对直喷式柴油机微粒排放粒度分布的影响规律,分析了柴油机微粒排放粒度分布特征。结果表明,柴油机的微粒排放大部分在1μm以下,以粒径50nm为分界,基本可以分为核态和积聚态两种。测试中微粒粒数浓度随着稀释比的增加而加大,同时微粒分布趋向核态。与转速相比,负荷变化对微粒粒度分布的影响较大,随着负荷的增大,核态PM所占比例减小。与欧Ⅲ柴油相比,生物柴油燃料核态微粒较多,积聚态微粒较少。天然气合成柴油燃料的核态和积聚态微粒浓度均低于欧Ⅲ柴油燃料,但其积聚态微粒浓度高于生物柴油燃料。 相似文献
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基于一台装有汽油机颗粒物捕集器(GPF)的1.4T进气道燃油喷射(PFI)发动机研究了发动机在不同负荷下的原始颗粒物排放特性和不同灰分载量对GPF过滤性能的影响。结果表明:在中小负荷下,发动机排放的颗粒物主要为核模态,在大负荷下,则存在粒径10~25 nm的核模态和100~200 nm的积聚模态颗粒物;灰分载量对GPF的工作特性有较大影响,灰分载量为0的GPF对颗粒物的捕集率约为85%,而灰分载量为5 g/L的GPF捕集率达97%;发动机排气背压、温度和燃油消耗率随GPF灰分载量的增加而提高,灰分载量为20 g/L时的燃油消耗率相比灰分载量为0时提高了3%~7%。 相似文献
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以装有汽油机颗粒过滤器(GPF)的2.0L缸内直喷增压汽油机(TGDI)为研究对象,研究了转速、负荷变化对发动机颗粒排放特性的影响,以及不同排温和不同灰分量对GPF的PN过滤效率的影响。结果表明:TGDI汽油机颗粒物排放随着负荷的增加呈现明显的先下降后上升的"U"型趋势。GPF再生过程中会出现GPF后PN数大于GPF前PN数的现象。灰分层的积累使汽油机颗粒过滤器过滤机理中的拦截沉积作用增强,过滤效率会随之增大。 相似文献
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柴油机微粒捕集器再生技术 总被引:3,自引:0,他引:3
与汽油机相比,柴油机产生的有害气体H C、CO排放量相当低,一般只有汽油机的几十分之一,柴油机NOx排放量和汽油机处于同一数量级,但柴油机微粒排放约为汽油机的30~80倍.因此,微粒排放是柴油机的显著特点.研究已经证实排气微粒能引起慢性肺炎,并加重支气管炎.美国环保局(EPA)的试验证明,吸附在微粒表面的可溶性有机物(SOF)具有诱变作用,其组分的90%以上为致癌物质.绝大多数排气微粒的粒径在0.01~0.1μm之间,能长时间悬浮在大气中,很容易通过呼吸系统进入肺泡中并沉积下来,较小的微粒甚至可以进入血液中,对人体健康的威胁更大. 相似文献
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环境温度对缸内直喷汽油车颗粒物排放特性的影响 总被引:1,自引:0,他引:1
利用电子低压冲击仪(ELPI)对一台满足国Ⅴ排放标准的缸内直喷汽油车进行了颗粒物排放特性研究。试验按照NEDC测试循环在转鼓试验台上进行,分别测量车辆在-15℃,-7℃和25℃下的颗粒物排放。通过对试验结果的研究表明:3个温度下,颗粒物的数量浓度随温度的下降大幅上升,粒径分布范围逐渐变大,均在相同粒径下出现峰值;颗粒物体积浓度随粒径的增大而增大;数量浓度对表面积浓度的影响大于体积浓度,尤其在-15℃下,这种影响更加显著。通过对颗粒物的瞬态排放结果的分析发现:3个温度下,颗粒物的排放主要集中在NEDC循环前200s,数量浓度随车辆的加速而上升,随减速而下降;在-15℃下,在整个NEDC循环的加速工况均出现表面积浓度的排放峰值,且峰值之间较为接近。 相似文献
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Bin Yang Wu Qiang Zhan Shun Kai Zhang Xiao Kun Nie Yu Han Li Wanhua Su 《International Journal of Automotive Technology》2018,19(4):623-633
Experiments and simulations were used to investigate the effect of a range of engine operating parameters and fuel characteristics on the particle size and particle number (PN) concentration at low speed and idle speed condition. The occurrence, size, and concentration of particles were tested against a range of parameters including start of injection (SOI), common rail pressure, exhaust gas recirculation (EGR) ratio and load. The results showed that the homogeneity of the mixture had the greatest impact on particle size and number concentration. The performance of particle is different at different levels of load. The particle were of nucleation mode at idle condition, and the cold idle particles had a slightly larger diameter than those produced at hot idle. By using the diesel and under high load, at EGR ratios of less than 20 %, most particles were of nucleation mode. At EGR ratios exceeding 20 %, nucleation-mode particles were gradually replaced by accumulation-mode particles. At EGR ratios above 30 %, most particles were of the accumulation mode. Under the same load, gasoline compression ignition produced particles of smaller size and reduced particulate mass (PM). The use of gasoline extended ignition delay, as the high volatility and octane number of the fuel improved the homogeneity of the mixture. Finally, a linear relationship was found between PM and PN. The relative contribution of the different factors to the formation of nucleationor accumulation-mode particles was investigated. 相似文献
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对同一台轻型两用燃料(C N G和汽油)车使用同一批次基准天然气和基准汽油,在底盘测功机上进行NEDC ,FTP75和WLTC循环对比试验,使用CVS定容取样系统和ELPI设备分析颗粒物等排放。研究发现:3种循环中,试验车辆燃用CNG和汽油,排放颗粒物在 Dp =40 nm和 Dp =330 nm附近均出现峰值,Dp =40 nm处汽油峰值远高于CNG ,Dp =330 nm处CNG峰值略高于汽油;CNG的PN和PM的排放率随车速的升高而增大,在较低的匀速工况下增长幅度较小,高速工况下增长幅度较大;CNG在NEDC循环中排放的核态和聚集态颗粒物各占50%左右,FTP75和WLTC循环中排放的聚集态颗粒物占比高于NEDC ;CNG在NEDC循环中单位里程颗粒数和颗粒总数最多,FTP75和WLTC循环中单位里程颗粒数基本相同;WLTC循环中排放的颗粒物质量总量最多,FTP75和NEDC循环中排放的颗粒物质量总量基本相同;FTP75和WLTC循环中单位里程排放的颗粒物质量基本相同,约为N EDC循环的2倍。 相似文献
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基于1台匹配废气再循环(EGR)系统的轻型柴油机,在中低负荷下研究了EGR对发动机超细颗粒排放的影响.研究发现:各工况下,随EGR率的增大,颗粒排放中核模态颗粒数量浓度在各粒径下有所减少,核模态颗粒排放数量速率和质量速率有减少趋势,且在最大扭矩转速的低负荷工况更加明显;积聚态颗粒数量浓度在各粒径下都增加,积聚态颗粒排放数量和质量速率也都增加,且中负荷时更加明显,而积聚态颗粒数量浓度峰值粒径基本没有改变.随EGR率的增大,总的超细颗粒排放数量速率在最大扭矩转速的低负荷工况减小,而其他工况都明显增加.由于积聚态颗粒总质量浓度占超细颗粒总质量浓度比例达99%,所以超细颗粒排放质量速率也都增加,几何平均粒径也都明显增大.在低负荷较低EGR率和中负荷较大EGR率时,过高的喷油压力都将使超细颗粒排放数量速率增加. 相似文献
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J. W. Lee Y. I. Jeong M. W. Jung K. O. Cha S. I. Kwon J. C. Kim S. Park 《International Journal of Automotive Technology》2008,9(4):397-403
In recent years, particle number emissions rather than particulate mass emissions in automotive engines have become the subject
with controversial discussions. Recent results from studies of health effects imply that it is possible that particulate mass
does not properly correlate with the variety of health effects attributed to engine exhaust. The concern is now focusing on
nano-sized particles emitted from I. C. engines. In this study, particulate mass and particle number concentration emitted
from light-duty vehicles were investigated for a better understanding of the characteristics of the engine PM from different
types of fuels, such as gasoline and diesel fuel. Engine nano-particle mass and size distributions of four test vehicles were
measured by a condensation particle counter system, which is recommended by the particle measurement program in Europe (PMP),
at the end of a dilution tunnel along a NEDC test mode on a chassis dynamometer. We found that particle number concentrations
of diesel passenger vehicles with DPF system are lower than gasoline passenger vehicles, but PM mass has some similar values.
However, in diesel vehicles with DPF system, PM mass and particle number concentrations were greatly influenced by PM regeneration.
Particle emissions in light-duty vehicles emitted about 90% at the ECE15 cycle in NEDC test mode, regardless of vehicle fuel
type. Particle emissions at the early cold condition of engine were highly emitted in the test mode. 相似文献
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The relationship between the oxygen content in gasoline and the particulate emission (particle number and weight) was investigated. In order to study the influence of the engine configuration on the particulate emission, four vehicles were tested in which the following systems were installed: Vehicle 1 was equipped with direct injection system which uses central mounted outwardly opening injectors. Vehicle 2 and 3 used direct injection with a side mounted multihole injectors and Vehicle 4 had port fuel injection system. Methyl tert-butyl ether (MTBE) was used as the oxygen booster. The oxygen content in the gasoline was varied from 1 to 3 wt%, which corresponds with an MTBE dosage from 3.55% to 16.11%. This study used fuel that contained the same octane number with a 2% oxygen content without oxygen components, and it was used as the reference fuel in order to distinguish the effect of the oxygen content increases and the octane boosts that result from the MTBE. All vehicle tests were performed on a roller type chassis dynamometer using the New European Driving Cycle (NEDC) and Federal Test Procedure-75 (FTP-75) cycle. The experiment results demonstrate that the oxygen content increases in the gasoline reduced the particulate emission in vehicles with direct injection engines. An equivalent phenomenon was observed in a vehicle with a port fuel injection engine, but its absolute particle number was much smaller than that of the gasoline direct injection engine. The amount of reduction of the particle number in the start (cold) phase of the test cycle was significant compared with the later (hot) phase engine operation. However, particulates were emitted even though the engine was fully warmed up, especially when the engine was highly loaded. Other factors such as fuel economy or other exhaust emissions were not significantly affected by the oxygen content. 相似文献
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A. Momenimovahed J. S. Olfert M. D. Checkel S. Pathak V. Sood L. Robindro S. K. Singal A. K. Jain M. O. Garg 《International Journal of Automotive Technology》2013,14(1):1-11
Nanoparticle and gas-phase emission factors are presented for a liquefied petroleum gas (LPG) passenger vehicle and are compared to gasoline operation. A bi-fuel LPG-gasoline vehicle certified for use on either fuel was used as the test vehicle so that a direct comparison of the emissions could be made based on fuel choice. These values were considered along with previous studies to determine the relative change in particulate emissions due to fuel choice over a wide range of vehicles and operating conditions. The vehicle examined in this study was tested on a chassis dynamometer for both steadystate and transient conditions. Transient test cycles included the US FTP72 driving cycle, Japanese driving cycle and modified Indian driving cycle while steady-state tests were done at vehicle speeds ranging from 10–90 km/hr in various transmission gears. Exhaust particle size distributions were measured in real-time using a differential mobility spectrometer (DMS50), and particle number and particle mass emission factors were calculated. For both fuels, the majority of the particles ranged from 5 to 160 nm in terms of particle diameter, with typically more than 85% of the particles in the nucleation mode (between 5–50 nm). In most cases, the vehicle produced a greater fraction of larger (accumulation mode) particles when fuelled on LPG. Using the data in the literature as well as the data in the current study, gasoline fuel produces 4.6 times more particles in terms of number and 2.1 times more particles in terms of mass. 相似文献
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This paper is review of the characterization of exhaust particles from state-of-the-art internal combustion engines. We primarily focus on identifying the physical and chemical properties of nano-particles, i.e., the concentration, size distribution, and particulate matter (PM) morphology. Stringent emissions regulations of the Euro 6 and the LEV III require a substantial reduction in the PM emissions from vehicles, and improvements in human health effects. Advances in powertrains with sophisticated engine control strategies and engine after-treatment technologies have significantly improved PM emission levels, motivating the development of new particle measurement instruments and chemical analysis procedures. In this paper, recent research trends are reviewed for physical and chemical PM characterization methods for gasoline and diesel fueled engines under various vehicle certification cycles and real-world driving conditions. The effects of engine technologies, fuels, and engine lubricant oils on exhaust PM morphology and compositions are also discussed. 相似文献