全合成机油黏度对增压发动机性能的影响

为了验证机油的黏度对发动机性能指标的影响,以国产某1.2 L排量增压发动机为例,使用较低黏度的美孚一号0W20 SN级代替原先使用的美孚一号5W30 SN级润滑油进行同一种状态的增压发动机性能对比台架试验。主要进行了净功率试验、机械损失试验、特征点油耗试验、万有特性试验等。结果发现:使用5W30机油的发动机动力性略优于使用0W20机油的发动机,经济性水平相当。因此,为发动机选用合适黏度的机油,能兼顾动力性和经济性。     

纳米减摩润滑剂在发动机中的应用效果研究

利用合成和复配技术制备了纳米减摩润滑剂,采用LPW4型柴油发动机考察了该润滑剂的实际应用效果,分析了纳米润滑剂对油品理化指标和减摩润滑性能的影响,研究了纳米润滑剂改善发动机油压、油耗和尾气排放等外特性的效果。结果表明:经过620 h的可靠性发动机试验,纳米润滑剂中金属元素Fe含量较专用机油降低了47.8%,机油压力提高了15.8%,说明纳米润滑剂具有优良的减摩润滑性能;与专用机油相比,纳米润滑剂的燃油消耗降低了3.6%,发动机的尾气颗粒含量降低了26.7%,排放烟度降低了51.3%,说明纳米润滑剂具有良好的节能效果和环保特性。这是由于纳米润滑剂充分利用了纳米特性和多种功能添加剂的复合协同功效,提升了传统润滑油的减摩润滑性能和整体性能。     

放心之选——常拖牌全喂入4LZ-2．5Z联合收割机

4LZ-2．5配套常柴／玉柴／新柴62．5kW（85hp）大功率涡流增压柴油发动机。更大的功率、更高的扭矩、更低的油耗、更少的燃料提供更大的功率和启动扭矩。脱粒系统采用纵轴流脱粒机，有振动筛和风扇组成的二次清洗，更为有效的减少损失，为机器进行高质量的脱粒。     

低黏度润滑油对涡轮增压发动机影响的试验研究

为了探究低黏度润滑油对涡轮增压发动机的影响,选用3种低黏度测试油0W20和参比油5W30进行台架试验,包括发动机机械损失试验和发动机万有特性试验。其中测试油0W20-1和0W20-2中添加了不同量的含钼摩擦改进剂,测试油0W20-3中添加了脂肪酸酯摩擦改进剂,且测试油0W20-1的黏度最低。选用黏度最低的测试油0W20-1进行发动机耐久试验。结果表明：在节气门全开和节气门全关2种工况下,含钼摩擦改进剂含量较高的测试油0W20-2摩擦力矩最小,相比参比油5W30分别可以降低发动机机械摩擦损失34.4%和19.3%;发动机的机械摩擦损失与摩擦改进剂的种类和添加量有关,相比脂肪酸酯摩擦改进剂,含钼摩擦改进剂更适应涡轮增压发动机工况,减少摩擦功的效果更好;低黏度润滑油能够提高车辆的燃油经济性,并且发动机关键摩擦副磨损量较小,满足发动机耐久性要求。     

甲醇汽油对发动机性能的影响

甲醇作为一种代用燃料,和汽油混合使用,人们对使用低比例甲醇燃料发动机的性能十分关注。汽车汽油发动机加入15%甲醇和85%汽油混合使用与加入100%汽油燃料分别经过300小时台架强化试验,测试发动机功率、扭矩及油耗率,得出使用15%甲醇和85%汽油混合燃料相对于100%汽油燃料仅是燃料消耗量高于汽油的9%。在汽油发动机中,直接使用15%甲醇和85%汽油混合燃料,除发动机经济性变差外,其他无变化或影响甚微。     

排气背压对发动机性能影响的研究

为研究排气背压对发动机扭矩、功率以及燃油消耗率的影响,通过分析排气背压对功率损失和充量系数的影响机理,利用相关台架试验,获得在不同背压时的发动机各个性能参数的变化曲线,分析其动力性及经济性的影响。结合理论分析及台架试验研究结果可得出:排气背压的增大会在一定程度上导致油耗增大、功率和扭矩降低,并且在不同转速范围内背压所造成的影响也不同。     

2011年1月起欧盟提高发动机排放标准

欧委会在2011年1月起．对非道路机械功率范围在130kW-560kW问的柴油发动机实施IIIB阶段排放标准。欧盟ⅢB阶段排放标准对发动机的排放微粒的限制，由0．2g／kWh降至0．025g／kWh。为达到此标准，柴油发动机必须配备微粒过滤器。     

二烷基二硫代甲酸钼(MoDTC)摩擦改进剂对GF-3等级全配方发动机油摩擦学性能的影响

利用SRV高温摩擦磨损试验机研究了二烷基二硫代甲酸钼(MoDTC)对渗氮活塞环／铸铁缸套在ILSACGF-3发动机油润滑条件下的摩擦学性能的影响。结果表明，MoDTC能与GF-3全配方发动机油中的ZDTP／磺酸钙添加剂体系产生协同作用，在活塞环和缸套表面生成减摩和抗磨的摩擦反应膜，从而显著降低并在较长时间内保持低摩擦系数(最低0．03)，同时缸套的磨损降低50％以上。     

一种油耗仪溢油问题的解决方法

发动机试验是验证发动机性能、品质及结构最基本的试验,针对在汽油发动机台架试验运行过程中,某发动机台架油耗仪经常出现溢油故障进行阐述,对该故障进行分析,并对现有供油管路系统进行改造,加装自动断油系统,从而有效地解决了油耗仪溢油故障。     

低黏度GF-60W-16发动机油节能摩擦模拟试验

为了进一步提高汽车燃料经济性,ILSAC颁布的节能发动机油规格已发展到黏度更低的GF-6级别。由于GF-6发动机节能台架试验周期长、成本高,为了提高开发GF-6 0W-16汽油机油配方的筛选效率,利用摩擦模拟试验分析0W-16汽油机油的摩擦润滑性能,并采用综合分析法研究摩擦模拟试验结果和发动机节能台架结果的相关性。结果表明：汽油机油配方中各添加剂之间的协同效应对其节油率和摩擦润滑性能产生显著影响,有机钼添加剂含量多的低黏度GF-6 0W-16汽油机油比参比油GF-5 0W-20更具减摩作用;试验温度激发汽油机油中有机钼减摩剂进一步发挥作用,降低摩擦因数;所建立的摩擦模拟试验综合分析法能够较好地预测低黏度GF-6润滑油节能台架试验结果。     

低黏度柴油发动机润滑油性能研究

根据国六排放法规对柴油发动机的发展和润滑油的性能要求开发了低黏度柴油发动机润滑油。选用10W40和5W30柴机油进行发动机台架试验,并通过发动机台架试验和整车道路试验重点考察了5W30对发动机节能和整车耐久性的影响。试验结果表明:采用低黏度柴油发动机润滑油可以提高柴油发动机的燃油经济性。     

Lubricating oil influence on exhaust hydrocarbon emissions from a gasoline fueled engine

Engine exhaust hydrocarbon emissions have been investigated for different lubricating oils, using gasoline as fuel. Six samples of lubricants have been tested: synthetic SAE 5W30 and SAE 5W40, semi-synthetic SAE 15W40 and SAE 20W50, and mineral SAE 15W40 and SAE 20W50. Experiments were carried out in a production engine mounted on a bench test dynamometer, varying engine load and speed in the range from 1500 to 6000 rev/min. The results demonstrate the influence of lubricant viscosity and base oil on hydrocarbon emissions. The synthetic oils showed the lowest hydrocarbon emission levels, especially in the low engine speed range.     

Effect of coconut oil‐blended fuels on diesel engine wear and lubrication

This paper presents the results of an experimental investigation into the wear and lubrication characteristics of a diesel engine using ordinary coconut oil (COIL)‐blended fuels. The blended fuels consisted of 10, 20, 30, 40, and 50% COIL with diesel fuel (DF2). Pure DF2 was used for comparison purposes. The engine was operated with 50% throttle setting at a constant speed of 2000 rpm for a period of 100 h with each fuel. The same lubricating oil, equivalent to SAE 40, was used for all fuel systems. A multi‐element oil analyser was used to measure wear metals (Fe, Cr, Cu, Al, and Pb), contaminant elements (Si, B, and V), and additive elements (Zn, Ca, P, and Mg) in the used lubricating oil. Fourier transform infrared analysis was performed to measure the degradation products (soot, oxidation, nitration, and sulphation products) in the used lubricant. Karl Fischer (ASTM D 1744) and potentiometric titrations (ASTM D 2896) were used to measure water concentration and total base number (TBN), respectively. An automatic viscometer (ASTM D 445) was used to measure lubricant viscosity. The results show that wear metals and contaminant elements increase with an increasing amount of COIL in DF2. An increasing amount of COIL in the blends reduces additive elements, with the reduction for blends of up to 30% COIL being quite similar to that for DF2. Soot and sulphation decrease with increasing COIL in the blended fuels due to reduced aromatics and sulphur in comparison to DF2. The water concentration increases for blended fuels with more than 30% COIL. The TBN and viscosity changes are found to be almost normal. The engine did not appear to have any starting and combustion problems when operating with the COIL‐blended fuels. The lubricating oil analysis data from this study will help in the selection of tribological components and compatible lubricating oils for coconut oil‐ or biofuel‐operated diesel engines.     

Demonstrating Improved Fuel Economy Using Subsystem Specific Lubricants on a Modified Diesel Engine

Fuel economy performance in modern internal combustion engines is of increasing importance to lubricant formulators due to regulations targeting global greenhouse gas emissions. Engines typically employ a single lubricant, with a common sump, to service all components. As a result, base oil and additive selection for fuel economy performance is a compromise among competing demands for different engine subsystems. Opportunities for significant fuel economy improvement through targeted formulation of lubricants for specific engine subsystems are presented, with specific emphasis on segregating the lubricant supplies for the valve train and the power cylinder subsystems. A working prototype was developed in a lab environment by modifying a commercially available twin-cylinder diesel engine. Motored valve train and whole-engine fired test results were obtained and compared to model data. Fuel economy benefits were demonstrated using market representative heavy-duty diesel lubricants, including mineral oil and polyalphaolefin (PAO) blends. The fuel economy benefits of a dual-loop lubricant system are demonstrated through significant viscosity reduction in the power cylinder subsystem, achieving overall engine friction reductions of up to 8% for the investigated operating condition. Results suggest that additional gains may be realized through targeted base oil and additive formulation. Implications for incorporation in larger diesel engines are also considered.     

金属陶瓷添加剂对船舶主机汽缸套-活塞环摩擦学行为的影响

将普通CD40润滑油作为基础润滑油，在3种不同的载荷作用下，对含有金属陶瓷添加剂润滑油对汽缸套-活塞环摩擦磨损特性的影响进行了模拟试验研究，并与实际使用的普通CD40润滑油的试验结果进行了比较。研究结果表明，汽缸套-活塞环摩擦副在这种添加剂作用下，其磨损失重及摩擦因数都大幅度降低。摩擦副表面扫描电镜分析结果也表明，这种添加剂使摩擦表面更光滑，其本身具有表面自修复作用。     

Henry's constants for ethanol,iso‐octane and gasoline absorption in engine lubricants

Henry's constants for hydrous ethanol, iso‐octane and gasoline absorption in engine lubricants were determined using gas chromatography. Samples of synthetic SAE 5 W30, synthetic SAE 5 W40, semi‐synthetic SAE 15 W40, mineral SAE 15 W40 and mineral SAE 25 W60 oil were used in the experiments. For all lubricants tested, typical molecular weights were considered, ranging from 500 to 5000 kg/kmol. The results show that, for any lubricant, Henry's constant for hydrous ethanol is about 2.2 times higher than that of gasoline, and about 4.3 times higher than that of iso‐octane. Decreasing Henry's constant was observed with increasing lubricant molecular weight, regardless of the fuel type. Copyright © 2014 John Wiley & Sons, Ltd.     

Lubricant viscosity and viscosity improver additive effects on diesel fuel economy

This work verifies the impact of lubricant viscosity and viscosity improver additives on diesel fuel economy. Eight lubricants were tested in a single-cylinder, four-stroke, direct injection diesel engine mounted on a dynamometer, under different load and speed conditions. Engine friction power was also investigated through Willans’ line. The results demonstrate that fuel economy obtained from multigrade viscosity oils is higher than that obtained from monograde viscosity oils. A linear relationship was obtained between the high temperature high shear viscosity and specific fuel consumption. The lubricant which provided lower fuel consumption also required lower friction power.     

Performance and emission studies on an agriculture engine on neat Jatropha oil

Diesel engines have proven their utility in the transportation, agriculture, and power sectors in India. They are also potential sources of decentralized energy generation for rural electrification. Concerns on the long-term availability of petroleum diesel and the stringent environmental norms have mandated the search for a renewable alternative to diesel fuel to address these problems. Vegetable oils have been considered good alternatives to diesel in the past couple of years. However, there are many issues related to the use of vegetable oils in diesel engine. Jatropha curcas has been promoted in India as a sustainable substitute to diesel fuel. This study aims to develop a dual fuel engine test rig for evaluating the potential suitability of Jatropha oil as diesel fuel and for determining the performance and emission characteristics of an engine with Jatropha oil. The experimental results suggest that engine performance using Jatropha oil is slightly inferior to that of diesel fuel. The thermal efficiency of the engine was lower, while the brake-specific fuel consumption was higher with Jatropha oil compared with diesel fuel. The levels of nitrogen oxides (NOx) from Jatropha oil during the entire duration of the experiment were lower than those of diesel fuel. The reduction of NOx was found to be an important characteristic of Jatropha oil as NOx emission is the most harmful gaseous emission from engines; as such, its reduction is always the goal of engine researchers and makers. During the entire experiment, carbon monoxide (CO), hydrocarbon (HC), and carbon dioxide (CO₂) emissions in the case of using Jatropha oil were higher than when diesel fuel was used. The higher density and viscosity of Jatropha oil causes lower thermal efficiency and higher brakespecific fuel consumption. The performance and emission characteristics found in this study are significant for the study of replacing diesel fuel from fossils with Jatropha oil in rural India, where the availability of diesel has always been a problem.     

Investigation of the effects of steam injection on the emissions and performance of a diesel engine using waste chicken oil methyl ester

The use of biodiesel-blended fuels in diesel engines improves the engine performance parameters and the partial recovery of incomplete combustion products, while also increasing the level of NOx emissions. In this study; biodiesel obtained through the transesterification of waste chicken frying oil was mixed with diesel fuel (90% diesel + 10% biodiesel-B10), and was then used as fuel in a direct injection diesel engine. To reduce the increased NOx emissions caused by the use of B10 fuel, the steam injection method (which is one of the NOx reduction methods) was applied. Steam was injected into the intake manifold at different ratios (5%-S5, 10%-S10 and 15%-S15) and at the time of the induction stroke with the aid of an electronically controlled system. Based on the study results, it was observed that steam injection into the engine using B10 fuel improved both the engine performance and the exhaust emission parameters. It was determined that the S15 steam injection ratio resulted in the best engine performance and emissions parameters. In comparison to STD fuel; the highest increase observed at the S15 steam injection ratio in the effective engine power was 2.2%, while the highest decrease in the specific fuel consumption was 3.4%, the highest increase in the effective efficiency was 3.5%, and the highest decrease in NOx emissions was 13.7%.