共查询到20条相似文献,搜索用时 62 毫秒
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采用扫气旁通系统改善车用高增压柴油机低工况性能的计算研究 总被引:4,自引:1,他引:3
采用扫气旁通系统(Scavengingby-pass简称Scaby系统)改善车用高增压柴油机低工况性能,运用“有限容积法”一维非定常流动模型进行了模拟计算研究。计算结果表明,采用Scaby系统可以改善车用高增压柴油机的低工况性能,并且能在一定程度上降低柴油机的机械负荷和热负荷。 相似文献
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我国车用柴油机的技术现状及发展趋势 总被引:2,自引:0,他引:2
本文分析我国目前车用柴油机制造技术与国际水平相比所存在的差距,预测今后若干年内车用柴油机将向节能降耗,应用增压技术,提高可靠性,降低排放,采用电控技术方面发展,以尽快接近和赶上国际先进水平。 相似文献
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减振钢板在内燃机降噪中的应用 总被引:1,自引:0,他引:1
论述了降低机械结构振动的方法及常用复合减振钢板的减振机理。分析了车用内燃机结构表面振动与辐射噪声的关系,并对一台车用大功率涡轮增压中冷柴油机进行台架试验,确定了油底壳及进气管为发动机主要噪声源。通过采用减振钢板取代原普通钢板的方法,使这两部件的振动水平显著降低,发动机整机噪声也得到了改善。 相似文献
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车用催化剂经历了约30年的发展,是催化领域,尤其是异相催化领域开发最为成功的一类催化剂。目前,车用催化剂的概念已不再局限于仅是一种排放后处理技术,用于改善燃烧过程、降低内燃机污染物生成量的燃油添加剂也是一种新型车用催化剂。 相似文献
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当今人们对车用发动机的要求愈来愈多,这就使得我们必须开发和使用一些新型材料,以提高发动机零部件的质量,增强其工作可靠性,延长其使用寿命,从而改善发动机的燃料经济性,降低发动机的噪声及有害排放。 相似文献
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文章介绍了代用燃料甲醇与二甲醚的物理化学性质与制备路线,并通过分析燃料的经济性,认为这两种含氧车用替代燃料既可以缓解能源安全问题,还能够降低汽车尾气排放,值得推广。 相似文献
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本文提出了电控汽油机提高燃油经济性,降低排放的三种措施,并介绍了各种措施的一些具体要求及实施手段,为车用电控汽油机进一步提高燃油经济性,降低排放提供了途径。 相似文献
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本文用多目标规划的方法设计了空燃比分布表格,在其指导下对油特性MA进行了匹配实验。以满足提高经济性和动力性,降低排放的要求; 相似文献
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柴油机的排放污染及控制措施 总被引:5,自引:0,他引:5
介绍了柴油机排放的污染物及其生成机理。在控制柴油机排放的措施中,首先介绍了提高柴油的着火性能、降低含硫量及使用柴油添加剂等;其次,阐述了改进柴油机的燃烧过程,即改进供油系统、改进供气系统、采用废气再循环技术等;最后,介绍了柴油机的排放后处理。 相似文献
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在我国,中重型货车是温室气体及污染物排放的主要贡献者,加快以柴油为主的中重型货车向电动化转型十分迫切,纯电动与燃料电池是当下最受重视的两条技术路线。纯电动路线在十多年的中短途运输和公共领域中的发展被证明是成功的;燃料电池路线在能量补给、能量密度等方面的优势比纯电动路线更适宜于长途重型货车的应用,目前正处于迅猛发展阶段。然而,以柴油牵引汽车为例,车辆可通过采用大油箱轻松达到 3 000 km的续驶里程,而当前的燃料电池牵引汽车的续驶里程正努力向500 km迈进,远不能与柴油汽车相比较。鉴于此,基于客户需求视角考虑,当下燃料电池重型货
车整车开发的主要矛盾,是过低的车载储氢量带来的续驶里程过低问题,这主要是由氢过低的体积存储密度决定的。提高燃料电池堆和燃料电池系统的能量转化效率虽然有助于提升续驶里程,但其前提是关键材料的技术突破。在当前整车开发中,最大限度地提升车载储氢量,降低辅助系统能耗,提高机械传动与电力电子系统效率,降低车辆行驶消耗更具有现实意义和可操作性。重点介绍在提升车载储氢量和降低车辆空气阻力系数方面的措施,以及对提升续驶里程的影响。按照《节能与新能源汽车技术路线图2.0》的愿景,能够实现燃料电池重型货车到2030年达到800 km的续驶里程的目标。 相似文献
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A. J. Torregrosa A. Broatch P. Olmeda C. Romero 《International Journal of Automotive Technology》2008,9(4):447-458
One of the major goals of engine designers is the reduction of fuel consumption and pollutant emissions while keeping or even
improving engine performance. In recent years, different technical issues have been investigated and incorporated into internal
combustion engines in order to fulfill these requirements. Most are related to the combustion process since it is responsible
for both fuel consumption and pollutant emissions. Additionally, the most critical operating points for an engine are both
the starting and the warming up periods (the time the engine takes to reach its nominal temperature, generally between 80°C
and 90°C), since at these points fuel consumption and pollutant emissions are larger than at any other points. Thus, reducing
the warm-up period can be crucial to fulfill new demands and regulations. This period depends strongly on the engine cooling
system and the different strategies used to control and regulate coolant flow and temperature. In the present work, the influences
of different engine cooling system configurations on the warm-up period of a Diesel engine are studied. The first part of
the work focuses on the modeling of a baseline engine cooling system and the tests performed to adjust and validate the model.
Once the model was validated, different modifications of the engine coolant system were simulated. From the modelled results,
the most favourable condition was selected in order to check on the test bench the reduction achieved in engine warm-up time
and to quantify the benefits obtained in terms of engine fuel consumption and pollutant emissions under the New European Driving
Cycle (NEDC). The results show that one of the selected configurations reduced the warm-up period by approximately 159 s when
compared with the baseline configuration. As a consequence, important reductions in fuel consumption and pollutant emissions
(HC and CO) were obtained.
On doctoral leave from Universidad Technológica de Pereira (Colombia) 相似文献
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J. Lee S. Choi H. Kim D. Kim H. Choi K. Min 《International Journal of Automotive Technology》2013,14(4):551-558
Recent studies on dual-fuel combustion in compression-ignition (CI) engines, also known as diesel engines, fall into two categories. In the first category are studies focused on the addition of small amounts of gaseous fuel to CI engines. In these studies, gaseous fuel is regarded as a secondary fuel and diesel fuel is regarded as the main fuel for combustion. The objectives of these studies typically involve reducing particulate matter (PM) emissions by using gaseous fuel as a partial substitution for diesel fuel. However, the addition of gaseous fuel raises the combustion temperature, which increases emissions of nitrogen oxides (NOx). In the second category are studies focused on reactivity-controlled compression-ignition (RCCI) combustion. RCCI combustion can be implemented by early diesel injection with a large amount of low-reactivity fuel such as gasoline or gaseous fuel. Although RCCI combustion promises lower NOx and PM emissions and higher thermal efficiency than conventional diesel combustion, it requires a higher intake pressure (usually more than 1.7 bars) to maintain a lean fuel mixture. Therefore, in this study, practical applications of dual-fuel combustion with a low air-fuel ratio (AFR), which implies a low intake pressure, were systemically evaluated using propane in a diesel engine. The characteristics of dualfuel combustion for high and low AFRs were first evaluated. The proportion of propane used for four different operating conditions was then increased to decrease emissions and to identify the optimal condition for dual-fuel combustion. Although the four operating conditions differ, the AFR was maintained at 20 (? approximately equal to 0.72) and the 50% mass fraction burned (MFB 50) was also fixed. The results show that dual-fuel combustion can reduce NOx and PM emissions in comparison to conventional diesel combustion. 相似文献
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This paper presents an accurate engine fuel injection quantity control technique for high pressure common rail (HPCR) injection
systems by an iterative learning control (ILC)-based, on-line calibration method. Accurate fuel injection quantity control
is of importance in improving engine combustion efficiency and reducing engine-out emissions. Current Diesel engine fuel injection
quantity control algorithms are either based on pre-calibrated tables or injector models, which may not adequately handle
the effects of disturbances from fuel pressure oscillation in HPCR, rail pressure sensor reading inaccuracy, and the injector
aging on injection quantity control. In this paper, by using an exhaust oxygen fraction dynamic model, an on-line parameter
calibration method for accurate fuel injection quantity control was developed based on an enhanced iterative learning control
(EILC) technique in conjunction with HPCR injection system. A high-fidelity, GT-Power engine model, with parametric uncertainties
and measurement disturbances, was utilized to validate such a methodology. Through simulations at different engine operating
conditions, the effectiveness of the proposed method in rejecting the effects of uncertainties and disturbance on fuel injection
quantity control was demonstrated. 相似文献