共查询到20条相似文献,搜索用时 125 毫秒
1.
柴油机排气微粒控制技术的发展 总被引:4,自引:0,他引:4
柴油机排放的大量微粒和NOx对环境的影响较为严重。回顾了柴油机排气微粒控制技术的发展历程,介绍了柴油机排气微粒控制的三种方法,指出虽然采用缸内措施及燃油质量的改善可大幅度降低微粒排放,但面对未来更为严格的排放法规,需要使用微粒后处理装置,对催化转换器和捕集氧化系统的技术发展进行了较为全面的评述。 相似文献
2.
在维持重型车用柴油机良好的燃油经济性的同时,降低其氮氧化物(NOx)和微粒(PM)排放的关键,是燃烧过程的进一步优化。阐述了喷油系统的改进、燃烧室设计的优化、4气门低涡流和可变涡流结构的采用等技术措施的潜力,以及一些诸如排气再循环、喷水和掺烧清洁燃料等附加措施的效果 相似文献
3.
4.
近年来,客车高速直喷式(HSDI)柴油机的性能得到很大改善,排气净化技术快速发展,噪声、振动与排气污染有所降低。同时,最大制动热效率已达到42 ̄43%,燃油经济性比较高。文中针对高速直喷式柴油机燃油喷射系统、燃烧系统以及排气后处理技术的多种实现形式作出了分析比较,并对其研究与发展进程进行了论述。最后,对满足未来超清洁、高性能要求的柴油机进行了展望。 相似文献
5.
6.
国外轿车TDI柴油机技术的新近发展 总被引:1,自引:0,他引:1
随着人们环境意识的不断增强,对低排放和保护资源的要求也日益提高。本文从轿车柴油机的市场需求出发,综述了国外轿车TDI柴油机技术的发展现状,如多气门技术、高压喷射和可变几何截面的涡轮增压器以及采用全电子发动机管理等,介绍了开发新型发动机、排气后处理技术以及改善燃油质量等方面的新近发展。 相似文献
7.
8.
采用稀氮氧化物(NOx)捕集器(LNT)+选择性催化还原(SCR)的复合排气后处理系统,使柴油车满足低排放车第2阶段及特低排放车70标准的要求。同时使燃油耗最小化。通过对LNT功能性及LNT+SCR复合排气后处理系统特点进行分析,建立一种不同于现有LNT系统的新型控制策略。在温度不低于200℃的条件下,SCR能够提供最稳定的NOx转化效率。对LNT的浓气再生进行优化,从而减缓其老化,并使燃油耗最小化。在SCR无法净化NOx期间,快速加热策略与原始NOx还原之间的优化匹配使LNT的NOx转化效率达到最大化。研究采用相当于15万mile1全生命周期的台架老化催化剂。在高速公路行驶循环中,SCR的转化率通常很高,此时可通过使LNT的降NOx量最小化及提高发动机燃烧效率来改善燃油经济性。为复合排气后处理系统的优化提供一种解决办法,获得能够满足美国环境保护署(EPA)15万mile排放法规要求的试验结果。还发现,能够满足海平面EPA美国联邦试验工况(FTP-75)排放法规的LNT+SCR系统,也能够满足高海拔条件下高速公路排放法规的要求。 相似文献
9.
Audi公司开发的新一代V6涡轮增压直喷式(TDI)柴油机系列使柴油动力装置获得进一步发展,其开发目标是在满足欧6排放法规要求的同时降低燃油耗,并进一步提高功率和扭矩。其中,集成模块化近发动机布置的排气后处理装置对达到上述目标起到关键作用,全新设计的链传动机构能为此提供自由的安装空间,因而能在低CO2排放水平下获得最佳的排气后处理效果。详细介绍新型V6-TDI柴油机的热力学、应用和排气后处理系统。 相似文献
10.
由于受到降低温室气体排放及改善汽车燃油耗要求的影响,日本国内自2018年起对总质量为3.5~7.5t的重型汽车开始执行废气排放法规。近年来,针对柴油机的技术研发工作重点在于改善其燃烧过程,同时采用全新的燃烧方式以降低废气排放及燃油耗。除了开发新型柴油机及排气后处理技术外,针对后处理装置的优化也势在必行。以2018年日本国内市场的新型柴油机研发成果为例,阐述了车用柴油机市场发展的趋势及技术动向。 相似文献
11.
This paper reviews the particle emissions formed during the combustion process in spark ignition and diesel engine. Proposed
legislation in Europe and California will impose a particle number requirement for GDI (gasoline direct injection) vehicles
and will introduce the Euro 6 and LEV-III emission standards. More careful optimization for reducing particulate emission
on engine hardware, fuel system, and control strategy to reduce particulate emissions will be required during cold start and
warm-up phases. Because The diesel combustion inherently produces significant amounts of PM as a result of incomplete combustion
around individual fuel droplets in the combustion zone, much attention has been paid to reducing particle emissions through
electronic engine control, high pressure injection systems, combustion chamber design, and exhaust after-treatment technologies.
In this paper, recent research and development trends to reduce the particle emissions from internal combustion engines are
summarized, with a focus on PMP activity in EU, CARB and SAE papers and including both state-of-the-art light-duty vehicles
and heavy-duty engines. 相似文献
12.
13.
为缓解全球气候变暖,可考虑在汽车发动机上燃烧零碳氨燃料以减少碳排放。但由于氨 (NH3)的燃点高、最小点火能量高以及燃烧缓慢等劣势,需要借助氢气 (H2) 作为助燃剂,帮助改善氨燃料发动机的燃料燃烧过程。针对国内外相关文献进行综述,总结了氨氢双燃料发动机掺混燃烧调控方法的研究进展,并分析了氨催化分解制氢与氨燃料发动机耦合的研究现状,发现采用氨燃料在线重整制氢可以避免采用双燃料供给系统。研究结果表明,氢气助燃能提高氨燃料发动机的燃烧速度,降低NOx的排放量。对于氨燃料发动机依旧存在的动力性能下降和未燃氨气排放等问题,仍需在今后的研究中探索解决。 相似文献
14.
For several decades, the primary goal of the automotive industry has been to reduce harmful emissions and improve fuel economy.
Gasoline engines are clean and powerful propulsion systems, but have poorer fuel economy than that of diesel engines. However,
due to the development of new technologies such as variable valve timing and lift and direct gasoline injection, controlled
autoignition (CAI) combustion can be realized. CAI engines combine the advantages of cleaner emissions and lower fuel consumption
than conventional spark-ignition gasoline engines. In this study, a cylinder-pressure-based combustion phase detection method
for CAI combustion is proposed. This method utilizes a normalized difference pressure (NDP), which is defined as the normalized
pressure difference between the firing and motoring in-cylinder pressures. The proposed method was developed and validated
with steady-state experimental data from an inline 4 cylinder, 2 L gasoline direct injection (GDI) CAI engine. Because the
calculations in the NDP method are faster and simpler than in the conventional combustion phase detection method in CAI engines,
this method can be embedded in a real-time controller. Furthermore, the proposed method displayed good accuracy in detecting
the combustion phase and thus stabilized CAI combustion. Finally, the detailed experimental results are presented. 相似文献
15.
A. Broatch J. M. Luján S. Ruiz P. Olmeda 《International Journal of Automotive Technology》2008,9(2):129-140
Most of hydrocarbon (HC) and carbon monoxide (CO) emissions from automotive DI Diesel engines are produced during the engine
warm-up period and are primarily caused by difficulties in obtaining stable and efficient combustion under these conditions.
Furthermore, the contribution of engine starting to these emissions is not negligible; since this operating condition is highly
unfavorable for the combustion progress. Additionally, the catalytic converter is ineffective due to the low engine temperature.
In conjunction with adequate engine settings (fuel injection and fresh air control), either the glow plugs or the intake air
heater are activated during a portion of the engine warm-up period, so that a nominal engine temperatures is reached faster,
and the impact of these difficulties is minimized. Measurement of gaseous pollutants during engine warm-up is currently possible
with detectors used in standard exhaust gas analyzers (EGA), which have response times well-suited for sampling at such transient
conditions. However, these devices are not suitable for the measurement of exhaust emissions produced during extremely short
time intervals, such as engine starting. Herein, we present a methodology for the measurement of the cumulative pollutant
emissions during the starting phase of passenger car DI Diesel engines, with the goal of overcoming this limitation by taking
advantage of standard detectors. In the proposed method, a warm canister is filled with an exhaust gas sample at constant
volumetric flow, during a time period that depends on the engine starting time; the gas concentration in the canister is later
evaluated with a standard EGA. When compared with direct pollutant measurements performed with a state-of-art EGA, the proposed
procedure was found to be more sensitive to combustion changes and provided more reliable data. 相似文献
16.
C. L. Myung K. H. Choi I. G. Hwang K. H. Lee S. Park 《International Journal of Automotive Technology》2009,10(2):161-166
In SI engines, valve events have a major influence on volumetric efficiency, fuel economy and exhaust emissions. Moreover,
swirl and tumble motions in the intake charge also improve combustion speed and quality by stratifying the mixture as well
as intensifying the mixing rate of air and fuel. This paper investigates the behaviors of an engine and the combustion phenomenon
for various intake valve timings and intake charge motions using CVVT system and port masking schemes. Test condition includes
a part load and a cold idle condition inclusive of a cold start of the engine. Time-resolved HC and NOx emissions were also
measured at an exhaust port to examine their formation mechanisms and behaviors with fast response HC/NOx analyzers. In conclusion,
the fast burning of fuel and improved combustion quality by enhanced charge motions reduced unburned HC emissions, and advancing
the intake valve opening reduced HC as well as NOx. Furthermore, HCs during the cold transient phase and idle conditions decreased
with recalibrated start parameters such as lean air-fuel ratio and spark retardation via the enhancement of intake charge
motions. 相似文献
17.
S. Lee 《International Journal of Automotive Technology》2008,9(4):429-436
This paper addresses the application of the perturbation/correlation method to optimizing the torque output of internal combustion
engines. This application was inspired by observations of the limitations in current techniques of the automotive performance
tuning industry. Performance issues such as errors from true optimum spark timing and fuel injector pulse width values as
well as convergence were considered for optimal tuning. The ability of the system to deal with engine cycle-to-cycle variations
and their effect on input parameters is also analyzed. 相似文献
18.
19.