汽油机几种节油技术的效果对比

应用GT-POWER软件计算了5款不同技术的发动机在同样动力输出条件下的有效燃油消耗率水平,为整车匹配低油耗发动机提供选择依据。通过计算对比,小排量增压直喷发动机在中小负荷的油耗优于大排量自然吸气发动机;发动机进一步小型化后,小负荷工况的油耗还有降低潜力;小排量的高压缩比米勒循环增压直喷发动机热效率最高,在整个负荷区油耗水平较优。因此,匹配同一车型在相同动力输出的条件下,小排量高压缩比米勒循环增压直喷(TGDI)发动机降油耗优势更大。     

上汽通用五菱推出凯捷280T车型 采用全新涡轮增压缸内直喷发动机

<正>近期,上汽通用五菱推出了凯捷280T车型,并对该款车型的发动机进行了优化,从而为用户带来更舒适的用车体验。凯捷280T车型搭载了全新的1.5T涡轮增压缸内直喷发动机。该款发动机采用了行业领先的35 MPa高压共轨系统及新一代涡轮增压系统,最高功率可达130 kW,最大扭矩可达290 N·m。     

直喷汽油机直接起动停止技术研究发展与展望

能源和环境危机给汽车工业界提出了挑战,直接起动停止技术作为一项"节能减排"的关键性技术,目前已经受到越来越多的关注。其中直喷汽油机由于其直喷的特殊性,能够不依靠起动电机而直接在缸内喷油点火起动发动机,使得直接起动停止技术在能够在更多的车型上推广应用。但时至今日,直喷汽油机的直接启动技术仍然存在着较大的技术难关,本文将对其发展过程中存在的一些关键性问题进行阐述,并展望未来发展方向。     

直喷汽油机燃油喷射时刻对经济性与PN排放的影响

在一款装备直喷涡轮增压汽油机的国六车型的开发过程中,针对发动机在WLTC循环中有些工况PN排放高的现象,对这些工况进行了台架扫点.通过优化SOI,降低了发动机的PN排放.试验结果表明,过早的喷油,由喷雾和活塞碰撞形成的油膜会导致PN排放显著升高.为了避免PN排放升高,应适当推迟SOI.在低负荷条件下,SOI设定在295...     

稀燃对甲醇直喷点燃式发动机性能的影响北大核心CSCD

将一台增压直喷米勒循环汽油机改制成高压缩比(13.8)甲醇直喷点燃式发动机,在2 750 r/min、平均有效压力(brake mean effective pressure,BMEP)为1.1 MPa及1.5 MPa工况下研究了稀燃对甲醇直喷发动机燃烧、排放及热效率的影响。结果表明:随过量空气系数λ增大,甲醇直喷发动机滞燃期和燃烧持续期逐渐延长,高稀释率下燃烧滞燃期和持续期明显短于汽油原机。在1.1 MPa BMEP工况下,发动机的稳定燃烧极限从汽油原机的λ=1.5拓宽到甲醇直喷的1.7以上。气体排放方面,随λ增大,甲醇直喷发动机HC排放逐渐增加,而CO排放先降低后升高,在λ=1.1附近CO排放最低。与汽油原机相比,甲醇直喷发动机在各过量空气系数下均表现出更低的NOx、HC及CO排放。热效率方面,发动机在BMEP为1.1 MPa下,汽油原机和甲醇直喷的最大有效热效率分别为39.8%和44.1%,热效率绝对值分别较当量比燃烧提升2.5%和3.2%。BMEP提高到1.5 MPa后,甲醇直喷发动机在λ=1.4实现了44.5%的最大有效热效率。     

FAI二冲程缸内直喷汽油机的研究

基于AX～100二冲程化油器式发动机进行了FAI(Free Armature Injection自由电枢喷射)缸内直喷二冲程发动机的台架试验研究，在原机的基础上设计改造了一个适合缸内直喷的燃烧室结构，获得了大量的缸内直喷的试验数据和电控参数的MAP图，并做了该直喷发动机和原化油器发动机的性能、燃油消耗和HC排放的比较。结果表明，FAI直喷技术能够成功地应用于二冲程发动机缸内直喷系统，极大改善了燃油短路的现象和扫气效率，在整个运行范围内燃油消耗大大降低，HC排放改善很多。     

中国第一台大功率缸内高压直喷压燃式天然气发动机上市

【本刊讯】由中国首家研发和生产缸内直喷天然气发动机的合资公司--潍柴动力西港新能源发动机有限公司推出的中国第一台大功率缸内高压直喷压燃式天然气发动机（简称“HPDI发动机”）上市发布仪式2012年3月13日在北京钓鱼台举行。该项目的开发成功,填补了国内天然气缸内直喷发动机在应用领域的空白。这一技术创新成果,将是中国天然气发动机发展史上的一个里程碑。     

二冲程半直喷航空发动机喷油策略研究

基于自主研发的二冲程低压半直喷航空发动机及控制系统,开展喷油控制策略及对发动机性能影响规律的研究。结果表明：对于不同的发动机运行工况,需要采取不同的喷油策略组合。在起动和怠速工况,采用进气道喷射的独立供油方式;在部分负荷及高负荷工况,采用进气道喷射和缸内直喷协同供油方式,随着发动机直喷比例的提高,燃油消耗率相应减小;与采用进气道喷射供油相比较,采用低压半直喷供油可以获得较理想的燃油经济性。     

增压直喷汽油机超级爆燃研究

缸内直喷和增压已成为当今汽油机技术的主流方向,然而,随着发动机小型化和动力性的提高,增压直喷汽油发动机出现了一种新的异常燃烧现象——超级爆燃,其严重影响着发动机性能和使用寿命。根据国内外超级爆燃的研究现状,在典型增压直喷汽油机上对不同的超级爆燃抑制方法进行了研究。结果表明:加浓、二次喷射、冷型火花塞都能够抑制超级爆燃。     

缸内直喷技术的应用

以一台1.5TGDI发动机为研究对象,介绍了缸内直喷技术在发动机上的应用情况,缸内直喷技术可以改善燃油经济性、提高扭矩功率输出、降低排放水平。     

直喷汽油机气门积碳的成因与对策研究

针对在用汽油直喷发动机出现的气门积碳现象,对比缸内直喷汽油机与进气道喷射汽油机气门积碳组分与成因的差异,分析了缸内直喷汽油机进气门积碳的主要形成机理、影响因素和生成途径,其中气门表面温度、机油的物理和化学性能起了关键作用。在上述分析基础上,探讨了在发动机设计与应用层面减少进气门积碳的措施。     

Automotive spark-ignited direct-injection gasoline engines

The development of four-stroke, spark-ignition engines that are designed to inject gasoline directly into the combustion chamber is an important worldwide initiative of the automotive industry. The thermodynamic potential of such engines for significantly enhanced fuel economy, transient response and cold-start hydrocarbon emission levels has led to a large number of research and development projects that have the goal of understanding, developing and optimizing gasoline direct-injection (GDI) combustion systems. The processes of fuel injection, spray atomization and vaporization, charge cooling, mixture preparation and the control of in-cylinder air motion are all being actively researched, and this work is reviewed in detail and analyzed. The new technologies such as high-pressure, common-rail, gasoline injection systems and swirl-atomizing gasoline fuel injectors are discussed in detail, as these technologies, along with computer control capabilities, have enabled the current new examination of an old objective; the direct-injection, stratified-charge (DISC), gasoline engine. The prior work on DISC engines that is relevant to current GDI engine development is also reviewed and discussed.The fuel economy and emission data for actual engine configurations are of significant importance to engine researchers and developers. These data have been obtained and assembled for all of the available GDI literature, and are reviewed and discussed in detail. The types of GDI engines are arranged in four classifications of decreasing complexity, and the advantages and disadvantages of each class are noted and explained. Emphasis is placed upon consensus trends and conclusions that are evident when taken as a whole. Thus the GDI researcher is informed regarding the degree to which engine volumetric efficiency and compression ratio can be increased under optimized conditions, and as to the extent to which unburned hydrocarbon (UBHC), NO_x and particulate emissions can be minimized for specific combustion strategies. The critical area of GDI fuel injector deposits and the associated effect on spray geometry and engine performance degradation are reviewed, and important system guidelines for minimizing deposition rates and deposit effects are presented. The capabilities and limitations of emission control techniques and aftertreatment hardware are reviewed in depth, and areas of consensus on attaining European, Japanese and North American emission standards are compiled and discussed.All known research, prototype and production GDI engines worldwide are reviewed as to performance, emissions and fuel economy advantages, and for areas requiring further development. The engine schematics, control diagrams and specifications are compiled, and the emission control strategies are illustrated and discussed. The influence of lean-NO_x catalysts on the development of late-injection, stratified-charge GDI engines is reviewed, and the relative merits of lean-burn, homogeneous, direct-injection engines as an option requiring less control complexity are analyzed. All current information in the literature is used as the basis for discussing the future development of automotive GDI engines.     

缸内直喷式汽油机燃用当量空燃比混合气的试验研究

缸内直接喷射式汽油机，要求部分负荷时在压缩过程后期喷入燃油，实现混合气分层燃烧，以获得好的经济性；在全负荷时，燃油在进气过程中喷入，采用化学计量比混合气，实现均质预混合燃烧，以保持汽油机升功率高和排放低的优点。本文将一台柴油机改装为缸内直接喷射汽油机，在试验台架上进行了高负荷时燃用当量空燃比混合气的试验研究，结果表明，与化油器式汽油机相比，高负荷时油耗降低了6％，未燃碳氢降低了31％，NOx排放降低了10％，取得了较为满意的结果。     

High-rate,valve-regulated lead–acid batteries — suitable for hybrid electric vehicles?

The possibility of replacing, with electric drive systems, at least some of the internal-combustion engines currently employed in road vehicles is being actively pursued by all the world's major automobile manufacturing companies. Minimum on-road emissions would be achieved by the adoption of pure electric vehicles, but the somewhat limited range available between charges of the batteries has led to a serious evaluation of hybrid electric vehicles as an acceptable compromise. In hybrids, a small internal-combustion engine, operated at high efficiency, will consume less fuel and produce less emissions than would a regular internal-combustion engine, and will allow considerable range extension over the pure electric vehicle. Eventually, an electric system which employs a fuel cell may become affordable. It is likely that all three systems — the pure electric, the hybrid electric, and the fuel cell system — will require battery support, particularly to provide boost power for acceleration and hill climbing. Although more expensive battery systems are being vigorously developed in pursuit of greater range per charge, the benchmark against which these systems are compared remains the valve-regulated lead–acid (VRLA) battery.     

Biodiesel improves lubricity of new low sulphur diesel fuels

In this work, biodiesel from waste vegetable oil was used as an additive in low sulphur diesel fuel in automobile engines. The result was a fuel mixture with high lubricating power. According to the lubrication trials, the experimental mixtures complied with lubricity conditions established by European regulations, even when only a small quantity of biodiesel was used. It was also found that the mixtures were compatible with different engine gaskets and engine lubricant. Lastly, bench tests were performed using an automobile engine with mixtures of diesel fuel without conventional lubricant additive and biodiesel. The results showed that engine performance curves were very similar to those obtained with diesel fuel and that contaminating emissions from the engine decreased substantially by including biodiesel in the fuel, except for nitrogen oxides.     

天然气发动机汽车的改装

面对石油日益紧张、燃油价格不断上涨以及越来越严格排放限制的局面,天然气发动机在城市公交得到广泛的应用。详细介绍了将原柴油车改装为天然气发动机汽车的过程、方法以及注意事项。     

缸内直喷汽油机燃油系统故障诊断技术

以大众TSI发动机为例,分析缸内直喷汽油机燃油系统的常见故障原因,总结了缸内直喷汽油机燃油系统的油压和油泵的检测、数据流读取分析、执行元件自测试、主要电控元件检测等故障诊断方法,介绍一起诊断技术应用的实际案例。     

GDI发动机研究概况

介绍GDI（gasoline direct injeetion）发动机的燃烧机理和进气道、高压油泵以及喷油器等的结构。与传统发动机相比，GDI发动机在节能与环保两个方面都具有PFI（port fuel injeetion）无法达到的优越性。     

活塞式内燃机燃用沼气的研究

简要介绍了沼气的产生、成分、物理化学性能以及活塞式内燃机燃用沼气可能发生的燃烧速度慢、后燃严重、排气温度高与热负荷大等问题，提出了掺烧和快速全烧两大措施；并相应研制出沼气-柴油双燃料发动机和火花点火全沼气发动机发电机组来适应这两种燃烧方式，取得了较好效果。最后提出将沼气提纯、加压，使其性能接近压缩天然气来作为汽车燃料的方案。     

玻璃纤维隔振垫在汽车发动机试验平台基础中的应用

通过工程实践，成功地用树脂胶合的玻璃纤维棉板作为汽车发动机试验平台基础中的隔振材料。该法集诸多隔振材料的优点于一身，为中小型汽、柴油发动机试验平台基础的隔振提供了一种价格低廉，施工方便，使用效果好的行之有效的方法。