共查询到20条相似文献,搜索用时 510 毫秒
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缸内直喷汽油机技术发展趋势分析 总被引:7,自引:0,他引:7
介绍了缸内直喷(GDI)发动机技术发展过程及现状。对比分析了GDI发动机与气门口喷射(PFI)发动机的性能特点,GDI发动机相对于成熟的PFI发动机仍具有较多优势。分析了GDI发动机技术发展面临的主要问题,可以看出,排放、燃烧稳定性等方面的问题限制了分层稀燃GDI发动机普遍应用。探讨了GDI发动机燃烧系统特点及发展趋势,阐述了过量空气系数a=1的GDI均质混合燃烧方式、分层充气或均质(a=1)充气的涡轮增压技术、优化燃烧系统扩大分层稀燃区域、实现GDI发动机的HCCI燃烧等4个GDI发动机技术发展方向。 相似文献
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现代社会很大程度上依赖于由内燃机驱动的汽车。尽管最近十多年来轿车柴油机(采用压缩点燃的燃烧概念)在世界上一些地区和国家取得了长足的发展,但是迄今为止,绝大多数轿车仍然是用汽油机(采用火花点燃的燃烧概念)驱动的。这两种传统的燃烧概念都有各自的局限性。人们长期以来试图突破这种局限性,于是产生了一种全新的内燃机燃烧概念:均质充量压缩点燃(HCCI:Homogeneous Charge Compression Ignition)。近年来,国外许多研究者正在加紧研究这种新的燃烧概念,极有可能给内燃机行业带来重大的革命,值得引起我国内燃机行业从业人员的注意。 相似文献
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S. Jung M. Ishida S. Yamamoto H. Ueki D. Sakaguchi 《International Journal of Automotive Technology》2010,11(5):611-616
For realizing a premixed charge compression ignition (PCCI) engine, the effects of bio-ethanol blend oil and exhaust gas recirculation
(EGR) on PM-NOx trade-off have been investigated in a single cylinder direct injection diesel engine with the compression
ratio of 17.8. In the present experiment, the ethanol blend ratio and the EGR ratio were varied focusing on ignition delay,
premixed combustion, diffusive combustion, smoke, NOx and the thermal efficiency. Very low levels of 1.5 [g/kWh] NOx and 0.02
[g/kWh] PM, which is close to the 2009 emission standards imposed on heavy duty diesel engines in Japan, were achieved without
deterioration of the thermal efficiency in the PCCI engine operated with the 50% ethanol blend fuel and the EGR ratio of 0.2.
It is found that this improvement can be achieved by formation of the premixed charge condition resulting from a longer ignition
delay. A marked increase in ignition delay is due to blending ethanol with low cetane number and large latent heat, and due
to lowering in-cylinder gas temperature on compression stroke based on the EGR. It is noticed that smoke can be reduced even
by increasing the EGR ratio under a highly premixed condition. 相似文献
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J. W. Chung J. H. Kang N. H. Kim W. Kang B. S. Kim 《International Journal of Automotive Technology》2008,9(1):1-8
Currently, due to the severity of world-wide air pollution by substances emitted from vehicles, emission control is being
enforced more strictly, and it is expected that the regulation requirements for emission will become even more severe. A new
concept combustion technology that can reduce the Nitrogen oxides (NOx) and PM in relation to combustion is urgently required.
As a core combustion technology among new combustion technologies for the next generation engine, the homogenous charge compression
ignition (HCCI) is expanding its application range by adopting a multiple combustion mode, a catalyst, direct fuel injection
and partially premixed charge compression ignition combustion using the split injection method. This paper used a split injection
method in order to apply the partially premixed charge compression ignition combustion method without significantly altering
engine specifications of the multiple combustion mode and practicality by referring to the results of studies on the HCCI
engine. Furthermore, the effects of the ratio of the fuel injection amount on split injection are investigated. From the test
results, the adequate combination of the ratio of the fuel injection amount for the split injection method has some benefit
on exhaust and fuel economy performance in a naturally aspirated single cylinder diesel engine. 相似文献
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柴油微引燃乙醇发动机采用进气道喷射乙醇、缸内直喷微量柴油引燃的方式进行燃料供给。基于单缸四冲程柴油机,对其燃烧、性能及排放特性进行研究,固定引燃柴油喷射量为发动机能实现压燃着火的最小值,在进气压力为0.15 MPa时比较不同乙醇喷射量的工况组,通过改变柴油喷射时刻进行工况扫描。结果表明,引燃柴油的喷射时刻对发动机的燃烧、性能和排放影响显著。柴油微引燃乙醇发动机在中高负荷能够稳定运行,指示热效率可达34%以上,通过适当调节柴油喷射时刻,可以有效控制未燃碳氢(UHC)、NO_x与CO排放,同时可以实现极低的炭烟排放。柴油微引燃乙醇发动机燃烧模式为预混合或部分预混合燃烧,燃烧有两阶段放热特征,改变引燃柴油喷射时刻,可以有效控制燃烧相位。 相似文献
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H. Q. Yang S. J. Shuai Z. Wang J. X. Wang 《International Journal of Automotive Technology》2013,14(1):19-27
A novel combustion concept namely “multiple premixed compression ignition” (MPCI) in gasoline direct injection compression ignition (GDICI) regime is proposed. Its predominant feature is the first premixed and followed quasipremixed combustion processes in a sequence of “spray-combustion-spray-combustion”. The multiple-stage premixed combustion decouples the pressure rise with pollutants formation process, which means the pressure rise rate and emissions can be reduced simultaneously, while achieving a high thermal efficiency. The gasoline MPCI mode has been demonstrated in a research engine with a compression ratio of 18.5. Gasoline with the research octane number (RON) of 94.4 was tested under 1400 rpm, 0.6 MPa IMEP conditions, without EGR and intake boosting. A parameter study of common rail pressure and intake temperature was implemented to investigate their effects on the performance of MPCI mode. Compared to the single-stage diffusion combustion in traditional diesel engines, the gasoline MPCI mode achieves lower emissions of soot, NO, CO, as well as slightly higher indicated efficiency, with a penalty of higher THC emissions when the common rail pressure is larger than 80 MPa in this study. With intake temperature sweeping, the gasoline MPCI mode also has the foregoing advantages compared to the diesel under the same operating conditions. 相似文献
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《JSAE Review》2001,22(2):147-150
There are many candidates as the prime mover of vehicles for the 21st century. Fuel cells, advanced gasoline engines, advanced diesel engines or other systems including combinations of various combustion engines with the electric motor. Overviews of the pros and cons for these prime movers are explained and the compression ignition combustion system of premixed mixtures is positively reviewed as the most promising system. 相似文献