Comparison of the Effects of Biodiesel and Mineral Diesel Fuel Dilution on Aged Engine Oil Properties

Dilution of engine oil occurs when fuel is injected late in the combustion cycle to regenerate the diesel particulate filter used for trapping particulate emissions. Fuel dilution reduces oil viscosity and the concentration of engine oil additives, potentially compromising lubricant performance. Biodiesel usage may compound these issues due to its oxidative instability, and its higher boiling point compared to mineral diesel potentially causes it to concentrate more in the oil sump.

In this work, different amounts of mineral diesel and biodiesel (soy methyl ester, SME) were combined with 15W-40 CJ-4 diesel engine oil in laboratory oil aging experiments. Fuel was added and oil samples were withdrawn at periodic intervals. The oils were analyzed using typical oil analysis procedures to determine their condition, and wear evaluations under boundary lubricating conditions were determined using a high-frequency reciprocating rig (HFRR). Results showed that fuel dilution accelerated engine oil degradation, with biodiesel having a larger effect. However, friction remained unchanged with dilution, and wear actually decreased for fuel-diluted oils after 48 h of aging compared to aging without fuel dilution. Examination of the tribofilms by ultraviolet (UV) and visible Raman spectroscopy as well as Auger electron spectroscopy showed that additional carbon-containing components were present on tribofilms formed from fuel-diluted oils. These fuel-derived components may be responsible for the decreased wear observed.     

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.     

用SRV试验机评价柴油机油摩擦磨损性能

采用SRV 4型摩擦磨损试验机为试验平台,以某商用车公司提供的发动机缸套-活塞环截取件作为摩擦副试验件,以15W-40 CF-4和15W-40 CI-4发动机油为润滑介质,建立评价柴油机油摩擦磨损性能的模拟试验方法,并使用该方法对油品配方中减摩剂的区分性及不同材质活塞环与润滑油的适配性等进行考察。试验结果表明:建立的模拟试验方法能较好地区分出具有优异抗磨性能的柴油机油,同样对油品配方中减摩剂和不同材质活塞环与润滑油适配性等有着较好的区分性,可以作为润滑油品开发者和OEM汽车厂家对油品配方开发和摩擦副材质筛选的模拟评价手段。     

Effect of palm oil methyl ester and its emulsions on lubricant degradation and engine component wear

This paper presents the results of experimental work carried out to evaluate the effect of palm oil methyl ester also known as palm oil diesel (POD) and its emulsions, as alternative fuels, on unmodified indirect‐injection diesel engine wear and lubricant oil deterioration compared with ordinary diesel (OD). A constant 2500 rpm engine setting at half throttle was maintained throughout the wear debris and lubricant oil analysis period for 20 h for each fuel system. Samples of lubricant oil were collected through a one‐way valve connected to the crankcase sump at intervals of 4 h. The first sample was collected immediately after the engine had warmed up. The same lubricating oil, a conventional SAE 30, was used for all experiments. A multi‐element oil analyser was used to measure metal wear debris and lubricating oil additive depletion for the used lubricating oil. An ISL automatic houillon viscometer (ASTM D 445) and potentiometric titration (ASTM D 2896) were used to measure the viscosity and total base number, respectively. The lubricant oil analysis results for POD, OD, and their emulsions containing 10% water by volume were compared. Very promising results were obtained. The accumulation of metal wear debris in crankcase oil samples was lower with POD and its emulsion compared with the OD fuel. The addition of 10% water (by volume) to POD showed a promising tendency for wear resistance.     

Effect of lubricating oil additives on particle size distribution and total number concentration in diesel engine

This paper investigates the characteristics of particle size distribution in exhaust gas of engine fuelled with pure diesel and with diesel mixed with base oil or with oil additives. The experiments are conducted on a turbocharged diesel engine with fast particulate spectrometer DMS 500 connected to the exhaust pipe. Base oil and two kinds of commonly used lubricating oil additives, antioxidant additives and antifoaming additives, are chosen to be added into the fuel, with the concentrations being 0.5%, 1.0% and 1.5% of fuel weight individually. The particle size distribution is measured under medium load (100 Nm) and full load at different speeds. The results indicate that the existence of base oil or oil additives shows great influence on particle size distribution. Copyright © 2012 John Wiley & Sons, Ltd.     

Major pathways for used oil disposal and recycling. Part 2

One of the main concerns with lubricating oil relates to used oil management for both industrial and engine oils, although the environmental impact of gasoline and diesel engine oils is the most critical. Provided that efficient management systems are in place, most used oil should not reach the environment, so, the major question is ‘how should we dispose of collected used oil?’ The first option lies in burning it as a fuel, the second in recycling (re‐claiming, reprocessing, re‐refining). The latter allows recovery of mineral base oils, which are valuable constituents of crude oil. In the first part of this paper, the author looked at the problems associated with used oil, its use as a fuel, and simple recycling. He went on to look at major re‐refining processes, starting with hydrogenation (KTI, Mohawk, BERC/NIPER, and PROP technologies). In Part 2 he covers other processes, including Safety Kleen, IFP/Snamprogetti, UOP Hylube, and vacuum distillation and clay treatment technologies.     

Performance and combustion characteristics of a diesel engine with titanium oxide coated piston using Pongamia methyl ester

Owing to the increasing cost of petroleum products, fast depletion of fossil fuel, environmental consideration and stringent emission norms, it is necessary to search for alternative fuels for diesel engines. The alternative fuel can be produced from materials available within the country. Though the vegetable oils can be fuelled for diesel engines, their high viscosities and low volatilities have led to the investigation of its various derivatives such as monoesters, known as bio diesel. It is derived from triglycerides (vegetable oil and animal fates) by transesterification process. It is biodegradable and renewable in nature. Biodiesel can be used more efficiently in semi adiabatic engines (Semi LHR), in which the temperature of the combustion chamber is increased by thermal barrier coating on the piston crown. In this study, the piston crown was coated with ceramic material (TiO₂) of about 0.5 mm, by plasma spray method. In this present work, the experiments were carried out with of Pongamia oil methyl (PME) ester and diesel blends (B20 & B100) in a four stroke direct injection diesel engine with and without coated piston at different load conditions. The results revealed 100% bio diesel, an improvement in brake thermal efficiency (BTE) and the brake specific fuel consumption decreased by about 10 % at full load. The exhaust emissions like carbon monoxide (CO) and hydrocarbon (HC) were decreased and the nitrogen oxide (NO) emission increased by 15% with coated engine compared with the uncoated engine with diesel fuel. The peak pressure and heat release rate were increased for the coated engine compared with the standard engine.     

The influence of engine oil on diesel exhaust emissions

Increasingly stringent emission legislation, together with the requirements for improved diesel engine performance, such as fuel economy, friction reduction, and extended drain intervals, have led to attention being focused on engine oil quality. The use of low‐friction engine oils can improve engine fuel efficiency and lead to a significant reduction of gaseous emissions. Therefore, engine oil is of importance when considering engine design parameters. This paper describes a study of the contribution of engine oil to diesel exhaust emissions. The investigations have shown that diesel engine particulate emissions as well as hydrocarbons and NO_X emissions depend on the lubricant oil properties, in particular on the sulphur content, volatility, and metal content.     

黏结石墨基固体润滑涂层在油介质中的摩擦学性能

为了探讨聚酰亚胺黏结石墨基固体润滑涂层在油介质中的摩擦学性能及其作用机制,采用MHK-500型摩擦磨损实验机对聚酰亚胺黏结石墨基固体润滑涂层在4种油介质(RP-3煤油、0#柴油、液体石蜡和SG 15W-40机油)中的摩擦磨损性能进行评价,并对其机制进行初步的探讨。结果表明:与干摩擦相比,涂层在4种油介质中的摩擦学性能都有显著提高,其中在柴油介质中涂层的抗磨性能提高最为突出,可能的原因是中等黏度的柴油介质在摩擦界面能形成足够厚的油膜,又能对涂层进行有效的冷却;同种油介质中,涂层在高速(2.56 m/s)、低载(1 120 N)下的耐磨性能明显优于低速(1.54 m/s)、高载(2 120 N)下的耐磨性能。     

以汽油和甲醇为燃料时小型二冲程发动机摩擦特性比较

采用往复振动机模拟小型二冲程发动机运转工况，实验研究汽油和甲醇为燃料时发动机气缸和活塞环间的摩擦特性，并比较分别使用润滑油新油、润滑油老化油、润滑油新油和老化油的混合油作为润滑油时气缸和活塞环间的摩擦特性。结果表明，以甲醇为燃料时的摩擦因数和磨损量均小于以汽油为燃料时的摩擦因数和磨损量，特别是使用添加了润滑油新油的燃料时的摩擦因数和磨损量最小。通过黏度和热重（TG）分析，探讨甲醇燃料改善气缸和活塞环间的摩擦特性的原因，结果表明，甲醇燃料具有较高的黏度和较低的摩擦因数，因而以甲醇为燃料时可以降低磨损     

基于GM(0,N)模型的油液光谱分析界限值制定

针对传统油液光谱分析界限值制定方法中以磨粒含量服从正态分布假设为前提的局限,提出应用GM(0,N)模型制定油液光谱元素数据分析界限值的方法,该模型不仅能正确拟合光谱数据,还能够体现各元素间相关关系。应用GM(0,N)模型对船舶柴油机实际光谱数据进行处理,结果验证了该方法的有效性。     

基于低摩擦的柴油机节能新方法研究

针对车用柴油机节能问题,提出一种基于低摩擦技术的柴油机综合节能方法。研究柴油机摩擦副低摩擦技术,采用涂层技术与润滑技术减少摩擦副磨损;搭建柴油机节能综合试验台,通过油耗仪和尾气分析仪检测节能减排效果。实验研究表明,采用涂层技术与耐磨润滑油,具有较好的节能效果,实现柴油机的节能,这为车用柴油机的节能减排提供了新的方法与思路。     

Wear debris associated with diesel engine operation

Ferrography is used to illustrate the types of wear particle associated with diesel engine operation. Examples include corrosion, adhesion and abrasion together with examples of debris introduced by both fuel and new lubricating oil. Wear debris associated with exhaust gas emission is also examined.     

Ionic Liquids as Novel Lubricants and Additives for Diesel Engine Applications

The lubricating properties of two ionic liquids (ILs) with the same anion but different cations, one ammonium IL [C₈H₁₇]₃NH.Tf₂N and one imidazolium IL C₁₀mim.Tf₂N, were evaluated both in neat form and as oil additives. Experiments were conducted using a standardized reciprocating sliding test with a segment of a Cr-plated diesel engine piston ring against a gray cast iron flat specimen. The cast iron surface was prepared with simulated honing marks as on a typical internal combustion engine cylinder liner. The selected ILs were benchmarked against conventional hydrocarbon oils. Substantial friction and wear reductions, up to 55% and 34%, respectively, were achieved for the neat ILs compared to a fully formulated 15W40 engine oil. Adding 5 vol% ILs into mineral oil has demonstrated significant improvement in the lubricity. One blend even outperformed the 15W40 engine oil with 9% lower friction and 34% less wear. Lubrication regime modeling, worn surface morphology examination, and surface chemical analysis were conducted to help understand the lubricating mechanisms for ILs. Results suggest great potential for using ionic liquids as base lubricants or lubricant additives for diesel engine applications.     

Soot–additive interactions in engine oils

Soot is known to cause engine wear. In this work, we focus on how engine oil formulation affects soot‐related wear, and how the lubricant‐derived anti‐wear film changes when soot is present. Friction and wear experiments of fully and partially formulated diesel engine oils (containing basestock, dispersants and viscosity modifiers) are conducted with a ball‐on‐disk rig in the presence of carbon black (CB) as a soot surrogate. The friction coefficient was largely unaffected by CB dispersed in the oils, but electrically insulating film formation, an indication of the formation of anti‐wear films, was decreased. Wear on the disk was found to either remain the same or decrease when CB was present, depending on the oil formulation. An examination of the lubricant‐derived films using Raman and Auger electron spectroscopies found that the presence of more abundant amorphous carbon and lesser amounts of anti‐wear film components on the surface was associated with higher wear. Copyright © 2009 John Wiley & Sons, Ltd.     

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.     

Major pathways for used oil disposal and recycling. Part 1

One of the main concerns with lubricating oil relates to used oil management for both industrial and engine oils, although the environmental impact of gasoline and diesel engine oils is the most critical. Provided that efficient management systems are in place, most used oil should not reach the environment, so, the major question is how to dispose of collected used oil. The first option lies in burning it as a fuel, the second in recycling (reclaiming, reprocessing, re‐refining). The latter allows recovery of mineral base oils, which are valuable constituents of crude oil. Mobile (on site) and fixed plants for industrial oil recycling will first be discussed, and the paper will look at the most modern re‐refining processes that produce base oils of as high quality as virgin base oils. Based on current re‐refining experience, the quality of finished lubricants blended from re‐refined base stocks is also noted. Re‐refining today may be of significant benefit to the economy and can, of course, protect the environment. All modern re‐refining technologies produce small amounts of by‐products in which toxic materials may have been concentrated. A final aspect of reprocessing used oil is to integrate it, after hydrogen treatment, into existing refineries. This valuable raw material can then be directly routed to a lube oil unit or even to a cracking unit for conversion to gasoline. The integration of used oil treatment processes into selected refineries may be the most effective pathway to used oil disposal. In this first part, the author looks at the nature of the problems associated with used oil, its use as a fuel, and simple recycling. He then goes on to look at major re‐refining processes, starting with hydrogenation (KTI, Mohawk, BERC/NIPER, and PROP technologies). Part 2 will describe other processes, including a range of vacuum distillation/clay treatment technologies.     

Study of performance and emission characteristics of IC engines by using diesel–water emulsion

Due to the shortage of petroleum products and its increasing cost, efforts are on to develop alternate fuels, especially diesel oil, for partial or full replacement. Also, internal combustion engines generate undesirable emissions during combustion process. The emissions exhausted in to the surroundings pollute the atmosphere and causes several problems. The emissions of concern are: unburnt hydrocarbons, oxides of carbon, and oxides of nitrogen (NO_X). Advanced diesel fuel formulations offer significant emission reductions to new and older in-use engines every time the fuel tank is filled. The addition of water to diesel fuel lowers particulate emissions by serving as diluents to the key combustion intermediates that lead to particulate formation. The incorporation of water also reduces NO_X emissions by lowering the peak combustion temperatures through high heat of vaporization. When using water blend diesel, the engine fuel system recognizes the liquid as diesel fuel because the water droplet is encapsulated within a diesel fuel. In this experiment, we have used single cylinder four-stroke engine and the water-blend diesel emulsion is used and the diesel emission test, emulsion emission test, and various gases has been analyzed; smoke meter test is also conducted for various rate of loads. The test results from the engine fuelled with water-blend diesel showed reduction in emissions as compared to that of engine fuelled with conventional diesel. The better emissions in the CI engine using water-blend diesel is due to the incorporation of water which reduces NO_X emissions by lowering the peak combustion temperatures. Water-blend fuel enhances fuel atomization by micro-explosion. The addition of water to diesel fuel lowers particulate emissions by serving as diluents to the key combustion intermediates that lead to particulate formation     

基于振动法的在线监测润滑油黏度传感器测试

开发一种基于振动法的在线监测润滑油黏度传感器,在恒温和变温状态下,通过实验室和柴油机台架实验测试传感器对润滑油黏度的响应,温度对传感器的影响及传感器的稳定性。结果表明,该传感器对润滑油黏度变化具有较高的响应和灵敏度,能准确测量润滑油黏度,且稳定可靠。     

纳米铜对车用柴油机磨合过程的影响研究

从改善车用柴油机台架磨合质量,缩短磨合时间的角度出发,利用油液检测光谱分析技术和扫描电镜分析,对CD40润滑油及添加纳米铜的CD40润滑油进行实车台架磨合试验。实验结果说明使用添加纳米铜的CD40润滑油的2#柴油机在台架磨合25 m in时,柴油机主要磨损性元素Fe、Pb和A l就处于平衡状态,而使用CD40润滑油的1#柴油机在台架磨合结束时,上述各元素仍处于上升趋势。试验结果证明纳米铜添加剂能够有效改善柴油机的磨合质量,缩短磨合时间。