国Ⅲ排放电控柴油机机油中碳黑的形成及控制

中重型电控共轨柴油机为满足国Ⅲ排放推迟喷油,带来了机油中碳黑迅速增加,机油过早劣化的问题。本文较详实地阐述了国Ⅲ排放共轨柴油机机油中碳黑的形成机理。通过对柴油机燃烧系统匹配的理论研究．探讨控制和降低柴油机机油中碳黑的措施．认为通过优化柴油机喷油结束时间与燃烧室唇口部位设计等能有效地解决这一问题。在一台排量为9升的国Ⅲ电控共轨柴油机上进行相关台架试验,对机油中的碳黑进行了监测,结果显示主要措施的有效性,即发动机运行30小时后,机油中碳黑含量为0．43％,远小于AVL的推荐值,为中重型电控共轨柴油机控制机油中碳黑．提供了燃烧系统的设计。     

基于SCR技术路线的国Ⅳ柴油机开发

在一台国Ⅲ电控重型柴油机上进行了基于自主电控共轨燃油系统、自主选择性催化还原( SCR)技术的国Ⅳ柴油机开发,系统研究了燃油系统、进排气系统、SCR系统等对柴油机性能和排放的影响,研究结果表明:通过优化增压系统参数,采用高轨压和小孔径喷嘴,在爆压限值条件下调整喷油定时,柴油机比油耗和烟度较原机大幅改善,SCR喷射系统在...     

电控共轨喷油系统柴油机性能的研究

介绍了电控共轨喷油系统在柴油机上的应用;进行了直喷柴油机与电控共轨喷油系统的匹配试验;研究了共轨压力、喷油提前角及转速、负荷等工作参数对柴油机性能的影响。结果表明,对于不同的工况选择合适的共轨压力和喷油提前角,可以降低燃油消耗率和最高爆发压力,改善排放,达到对柴油机性能的综合要求。     

轨压和喷油提前角对柴油机排放影响的试验研究

以自吸式4缸直喷电控高压共轨柴油机为例,试验研究柴油机排放中NO_x和颗粒物随轨压和喷油提前角的变化规律。结果表明:一定喷油提前角范围内,NO_x排放随着轨压的增大而升高,烟度随着轨压的增大而降低;喷油提前角大于一定值时,NO_x排放与烟度受轨压影响较小;选择适当的喷油提前角并调整轨压能够有效降低NO_x排放及颗粒物排放,使柴油机排放满足要求。     

轨压与喷油提前角对柴油机NO_x排放和烟度的影响

结合某直列三缸,直喷式,电控高压共轨柴油机的非道路八工况排放试验,研究不同轨压和喷油提前角对柴油机NO_x排放和烟度的影响。结果显示,NO_x排放量随着轨压的增大而升高,随着喷油提前角的增大而升高。烟度随着轨压的增大而降低,随着喷油提前角的增大而降低。合理选择轨压和喷油提前角能够有效地降低NO_x排放和颗粒,柴油机能够满足非道路国Ⅳ排放要求。     

高压共轨柴油机标定优化研究

针对自主开发的高压共轨电控柴油机,以经济性作为优化目标,以排放物的量值低于排放法规所限定的量值为约束条件,利用离线稳态优化标定方法,对控制参数如轨压、喷油提前角等的MAP进行了优化标定;研究了轨压、喷油提前角等参数对燃油消耗率和NOx排放的影响。研究结果表明:经控制参数优化,在全工况下,该高压共轨柴油机的燃油消耗率下降约为6%。     

电控共轨系统分析及其对排放的影响

在分析了几种柴油机电控共轨式燃油系统的基础上,讨论了电控共轨系统对喷油压力、喷油量、喷油率形状和喷油时间可自由调节的特点,分析认为,电控共轨系统提高了喷油压力,实现了柔性可调的喷油规律,对柴油机排放降低、经济性和动力性提高起促进作用。     

匹配皮卡的CA4DC2-10E3柴油机开发

匹配皮卡车型的CA4DC2-10E3柴油机以CA4DC2-12E3国Ⅲ排放电控共轨柴油机为基础,设计了冷却EGR系统,并在台架上进行了标定开发工作。整车在转毂上匹配了氧化型后处理器,同时优化了标定。试验结果表明:样车排放达到了国Ⅲ标准,整车排放循环工况百公里油耗为8.8升。     

电控高压共轨低排放D114柴油机的研制

在现已批量生产的D114柴油机的基础上,为满足欧Ⅲ排放法规的要求,研制开发了低排放的D114电控高压共轨柴油机。研究结果表明,电控共轨系统具有较好的应用适应性,可改善柴油机的整机性能,达到欧Ⅲ排放标准。     

用电控VE泵的车用国Ⅲ柴油机性能参数优化与模拟计算

利用AVL-BOOST发动机模拟软件建立了以电控VE泵作为喷油系统的4C28车用柴油机的计算模型,以柴油机性能优化、排放达车用国Ⅲ标准为目标,分析探讨了不同压缩比、不同喷油提前角以及配气相位对柴油机性能的影响.对优化的样机进行了Nox排放模拟计算,结果表明柴油机的排放达到了国Ⅲ排放标准.模拟了柴油机外特性的性能,并和改进的样机试验值进行了比较,结果表明模拟值和试验值是一致的,样机的排放试验结果达到了国Ⅲ排放标准限值.     

Combustion of jojoba methyl ester in an indirect injection diesel engine

An experimental investigation has been carried out to examine for the first time the performance and combustion noise of an indirect injection diesel engine running with new fuel derived from pure jojoba oil, jojoba methyl ester, and its blends with gas oil. A Ricardo E6 compression swirl diesel engine was fully instrumented for the measurement of combustion pressure and its rise rate and other operating parameters. Test parameters included the percentage of jojoba methyl ester in the blend, engine speed, load, injection timing and engine compression ratio. Results showed that the new fuel derived from jojoba is generally comparable and good replacement to gas oil in diesel engine at most engine operating conditions, in terms of performance parameters and combustion noise produced.     

燃用小桐子油柴油机怠速工况工作过程及循环波动

采用柴油、柴油-小桐子掺混油、小桐子油、高温小桐子油,在单缸水冷四冲程柴油机上进行了怠速工况试验,测录了多循环的瞬时气缸压力与高压油管燃油压力,对比分析了喷油与燃烧过程中各参数的循环波动。结果发现,怠速工况喷油过程中,喷油持续期的循环波动最明显,小桐子油的喷油始点滞后,喷油持续期长,喷油压力大,喷油过程的循环波动略大;怠速工况燃烧过程中,最大燃烧压力升高率和滞燃期的循环波动率最为明显,小桐子油滞燃期略短,燃烧压力升高率小,最高燃烧压力低,滞燃期和最大燃烧压力升高率的循环波动明显大于柴油;燃用小桐子油增大了原机的循环波动,怠速运转不如柴油稳定。     

正丁醇/柴油发动机燃烧排放特性及喷油、燃烧室形状影响

针对某型号直喷柴油机,建立了该柴油机中单缸完整燃烧室及气道三维模型,使用三维计算流体力学(computational fluid dynamics,CFD)分析软件CONVERGE对其进行模拟计算,研究了正丁醇掺混比例对柴油机燃烧排放的影响。结果表明:随着正丁醇掺混比例的提高,峰值缸压、滞燃期和燃烧速度均呈递增趋势,碳烟及CO排放量逐渐减少,NO_x排放量小幅增加。为了进一步改善缸内燃烧情况和降低污染物排放,对正丁醇掺混时喷油策略、燃烧室几何形状的综合影响进行了研究,结果表明:掺混时多次喷油及采用合适的燃烧室模型可以有效改善掺混后缸内油气混合情况,增加缸内湍动能强度,进一步降低碳烟排放量。与纯柴油工况对比,掺混并采用多次喷油策略后碳烟排放明显下降,且通过掺混能够有效简化喷油策略,但弱化了燃烧室形状对碳烟排放量的影响。     

YZ485ZLQ柴油机润滑系统性能与主油道压力特性试验

采用台架试验方法,进行YZ485ZLQ柴油机润滑系统的整体性能和主油道的压力特性试验,探讨在YZ485QB柴油机基础上改进的YZ485ZLQ柴油机润滑系统性能。结果表明,YZ485ZLQ柴油机润滑系统性能良好,满足使用要求。转速变化对主油道压力的影响明显,润滑油温度变化对主油道压力的影响次之并呈现较强的非线性关系,负荷变化对主油道压力的影响最小。随着柴油机转速的增加,润滑系统中主油道的压力不断增加,最后趋于稳定值;随着柴油机负荷和润滑油的温度增加,主油道的润滑油压力下降。     

低排放单缸风冷柴油机的优化设计与匹配

以非道路单缸风冷192 F柴油机为研究对象,匹配蓄压式喷油系统,以低排放为核心目标,计算并设计了高压油泵凸轮和电控喷油器喷嘴参数,优化了螺旋进气道,重新设计了燃烧室几何形状并优化了喷油油线在燃烧室的分布,使燃烧室、进气道与蓄压式喷油系统相匹配.在标定工况、最大转矩工况下进行了喷油参数对工作过程、排放和性能影响的研究,以...     

The use of Koroch seed oil methyl ester blends as fuel in a diesel engine

An experimental investigation was carried out on a small direct injection (DI) diesel engine, fuelling the engine with 10% (B10), 20% (B20), 30% (B30) and 40% (B40) blending of Koroch seed oil methyl ester (KSOME) with diesel. The performance and combustion characteristics of the engine at various loads are compared and analyzed. The results showed higher brake specific fuel consumption (BSFC) and lower brake thermal efficiency (BTE) for the KSOME blends. The engine indicated power (IP) was more for the blends up to B30, but found to be reduced for the blend B40 when compared to that of diesel. The engine combustion parameters such as pressure crank angle diagram, peak pressure, time of occurrence of peak pressure, net heat-release rate, cumulative heat release, ignition delay and combustion duration were computed. The KSOME blends exhibited similar combustion trend with diesel. However, the blends showed an early start of combustion with shorter ignition delay period. The study reveals the suitability of KSOME blends up to B30 as fuel for a diesel engine mainly used in generating sets and the agricultural applications in India without any significant drop in engine performance.     

Performance characteristics of a low heat rejection diesel engine operating with biodiesel

Vegetable oils are a promising alternative among the different diesel fuel alternatives. However, the high viscosity, poor volatility and cold flow characteristics of vegetable oils can cause some problems such as injector coking, severe engine deposits, filter gumming, piston ring sticking and thickening of lubrication oil from long-term use in diesel engines. These problems can be eliminated or minimized by transesterification of the vegetable oils to form monoesters. These monoesters are known as biodiesel. The important advantages of biodiesel are lower exhaust gas emissions and its biodegradability and renewability compared with petroleum-based diesel fuel. Although the transesterification improves the fuel properties of vegetable oil, the viscosity and volatility of biodiesel are still worse than that of petroleum diesel fuel. The energy of the biodiesel can be released more efficiently with the concept of low heat rejection (LHR) engine. The aim of this study is to apply LHR engine for improving engine performance when biodiesel is used as an alternative fuel. For this purpose, a turbocharged direct injection (DI) diesel engine was converted to a LHR engine and the effects of biodiesel (produced from sunflower oil) usage in the LHR engine on its performance characteristics have been investigated experimentally. The results showed that specific fuel consumption and the brake thermal efficiency were improved and exhaust gas temperature before the turbine inlet was increased for both fuels in the LHR engine.     

增压柴油机燃用不同掺比菜籽油甲酯的燃烧和排放的试验研究

在D6114ZLQB车用增压柴油机上比较研究了不同比例的菜籽油甲酯和0号柴油的混合燃料对发动机燃烧过程、燃油经济性和排放特性的影响。试验结果表明：燃用体积比低于15%的菜籽油甲酯,发动机的缸内燃烧过程和纯柴油基本一致;增压柴油机燃用菜籽油甲酯和柴油的混合燃料可以有效降低碳烟、HC和CO的排放;NOx排放略有上升;15%以内的菜籽油甲酯对柴油机燃料经济性影响很小。研究认为：增压柴油机相对自然吸气式柴油机具有更好的生物柴油燃料适应性;在不改变发动机参数的条件下,低比例的菜籽油甲酯具有良好的推广应用前景。     

Hydrogen impacts on performance and CO2 emissions from a diesel power generator

This work investigates the performance and carbon dioxide (CO₂) emissions from a stationary diesel engine fueled with diesel oil (B5) and hydrogen (H₂). The performance parameters investigated were specific fuel consumption, effective engine efficiency and volumetric efficiency. The engine was operated varying the nominal load from 0 kW to 40 kW, with diesel oil being directly injected in the combustion chamber. Hydrogen was injected in the intake manifold, substituting diesel oil in concentrations of 5%, 10%, 15% and 20% on energy basis, keeping the original settings of diesel oil injection. The results show that partial substitution of diesel oil by hydrogen at the test conditions does not affect significantly specific fuel consumption and effective engine efficiency, and decreases the volumetric efficiency by up to 6%. On the other hand the use of hydrogen reduced CO₂ emissions by up to 12%, indicating that it can be applied to engines to reduce global warming effects.