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.     

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.     

Analysis of engine oil and phosphorus volatility

An apparatus has been designed that allows the measurement of phosphorus volatility, which is important in, among other things, controlling the degradation of exhaust catalysers in automobiles. Following on from the original Noack volatility test, the Selby—Noack apparatus can measure up to 99.9% of volatiles. The apparatus has been used in the present work to assess the relationship between engine oil volatility and engine oil phosphorus volatility (from additives), some reflections on which are presented.     

电控汽油喷射发动机燃油压力的测量方法

介绍了对电控发动机进行性能检测与故障诊断的基础项目之一的燃油压力检测的具体方法,并通过分析检测结果对燃油系中的一些元件做出性能判断.     

Evaluation of metallic elements in oil for an engine fault‐diagnosis system

One of the main problems in using oil analysis for predictive maintenance is the processing of the results. The oil analysis technique allows one to obtain relevant information about the state of the lubricant, the engine, and other auxiliary elements. However, it is necessary to process this information and to define the references with which the numerical results must be compared. The evaluation of metallic elements, wear particles, or contamination particles is more difficult, because factors such as engine metallurgy, engine use, and age must be considered. Therefore, the effect of various factors on the value measured, such as refills, different periods of sample taking, or types of oils, must be eliminated. A system to evaluate metallic elements in oil for an engine fault‐diagnosis system is presented in this paper.     

The impact of biofuels on engine oil performance

The dilution of biogenic fuels into lubricating engine oils often leads to a shortening of the recommended oil drains (between 30% and 60%) and an increase in wear. The large number of overlapping and influencing factors, of which dilution and polymerization of fuel components in the engine oil are emphasised, makes it difficult to find a uniform solution to prevent failures in the various applications. Insofar single solutions for the different types of biofuels are needed. The contribution of base oil chemistry and additives as well as triboactive materials is featured to deal with the adverse effects of biofuels. In the frame of the European Commission (EC)‐funded project ‘cleanengine’, tentative engine oils based on esters with a content of renewables and polyglycols are formulated to increase the lubricant's tolerance in engines fuelled with biofuel‐based blends, with the aim of ensuring required lubricating and wear protection performance while keeping oil drain intervals unchanged. The present paper focuses on four‐stroke diesel applications, fuelled by biodiesel (fatty acid methyl ester — FAME) as well as by rapeseed oil and Jatropha oil (pure vegetable oils, triglycerides), together with relevant blends of those biofuels and conventional diesel fuel. This paper screens the functional profile (in particular rheological, toxicological, bio‐compatibility, tribological and biofuels affinity) of lube families with respect to biofuel contamination. Moreover, this is followed by the contributions of piston ring and liner materials as well as thin film coatings. Copyright © 2011 John Wiley & Sons, Ltd.     

Effects of refined palm oil (RPO) fuel on wear of diesel engine components

In this particular research work, the effects of refined palm oil (RPO), as alternative fuel, on wear of diesel engine components are assessed. Fleet testing is carried for the qualifying candidates diesel fuel replacement, i.e. 100% RPO fuel or 50% RPO and 50% conventional diesel fuel mixture. The base line of the fleet testing is using pure conventional petroleum diesel fuel as an energy source in one of the tested vehicles in the fleet. Analysis of used engine lubrication oil, taken when the oil was changed on the vehicles, was compared to the analysis of used oil samples pulled from 100% diesel fuel engines. The finding suggested that the pure RPO and RPO blended fueled engines were wearing at a normal rate.     

Analysis of oil consumption in cylinder of diesel engine for optimization of piston rings

The performance and particulate emission of a diesel engine are affected by the consumption of lubricating oil.Most studies on oil consumption mechanism of the cylinder have been done by using the experimental method,however they are very costly.Therefore,it is very necessary to study oil consumption mechanism of the cylinder and obtain the accurate results by the calculation method.Firstly,four main modes of lubricating oil consumption in cylinder are analyzed and then the oil consumption rate under common working conditions are calculated for the four modes based on an engine.Then,the factors that affect the lubricating oil consumption such as working conditions,the second ring closed gap,the elastic force of the piston rings are also investigated for the four modes.The calculation results show that most of the lubricating oil is consumed by evaporation on the liner surface.Besides,there are three other findings:(1) The oil evaporation from the liner is determined by the working condition of an engine;(2) The increase of the ring closed gap reduces the oil blow through the top ring end gap but increases blow-by;(3) With the increase of the elastic force of the ring,both the left oil film thickness and the oil throw-off at the top ring decrease.The oil scraping of the piston top edge is consequently reduced while the friction loss between the rings and the liner increases.A neural network prediction model of the lubricating oil consumption in cylinder is established based on the BP neural network theory,and then the model is trained and validated.The main piston rings parameters which affect the oil consumption are optimized by using the BP neural network prediction model and the prediction accuracy of this BP neural network is within 8%,which is acceptable for normal engineering applications.The oil consumption is also measured experimentally.The relative errors of the calculated and experimental values are less than 10%,verifying the validity of the simulation results.Applying the established simulation model and the validated BP network model is able to generate numerical results with sufficient accuracy,which significantly reduces experimental work and provides guidance for the optimal design of the piston rings diesel engines.     

Statistical study of organomolybdenum compounds in an engine oil formulation and the results of engine testing

Organomolybdenum compounds are versatile lubricant additives of interest in the design of engine oils to meet the new ILSAC (International Lubricant Standardization and Approval Committee) GF‐3 performance standard, especially for fuel efficiency. In this work, organomolybdenum and 13 other components were studied by experimental design and statistical analysis to determine their effects on friction, wear, and oxidation properties. The resulting linear model was used to construct a trial engine oil formulation. Engine test results, including some new tests required for ILSAC GF‐3, confirmed some of the strengths of organomolybdenum compounds, as well as their sensitivity to other additives in the formulation.     

航空发动机滑油磨粒在线监测

航空发动机轴承部件磨损是导致发动机失效,引起飞机重大事故的主要因素之一。分析了航空发动机突发性剧烈磨损的疲劳磨损失效机理,陈述了磨粒尺寸和数量表征磨损程度的关系,系统介绍了各种航空发动机滑油磨粒在线监测技术,讨论了各技术方法的原理、技术特点、典型参数、典型应用、最新研究成果及技术适应性。滑油磨粒在线监测技术,能有效发现航空发动机突发性剧烈磨损,及时预警失效,避免出现重大事故,具有重大工程应用价值。     

Mathematical model for the thickening power of viscosity index improvers: Application to engine oil formulations

It is essential for a lubricating oil blender to be able to quantify the contribution that each component entering in a formulation makes to the viscosity of the finished product. In this context several studies have been devoted to the modelling of the thickening power of different types of polymers at both high (100 °C and 40°C) and low (−15°C) temperature in base oils of various origins and viscosities. To complement these earlier investigations, it is necessary to quantify the effect of the additive package on the viscosity of the formulation. For this purpose, the effect of several DI packages of different performance levels has been investigated in order to derive appropriate mathematical models representing the contribution of these packages to oil viscosity.     

Measurement of oil film thickness in big-end bearings and its relevance to engine oil viscosity classifications

Minimum oil film thickness MOFT measurements have been carried out in big-end bearings of V6 and in-line four-cylinder gasoline engines during engine operation. MOFT decreases with increasing crankshaft speed above 2000 r/min. The most severe practical steady-state operation is high-speed cruising. Maximum shear rates are in the region of 10⁷s⁻¹ at 4000 r/min. the dynamic viscosities at a shear rate of 10⁶s⁻¹ correlate significantly better with monograde MOFT data than with multigrade data; the correlation parameters for mono- and multigrade data are also significantly different. Although the dynamic viscosity measurement correlates with multigrade data better than the low-shear rate kinematic viscosity, the differences are not always significant at the 95% confidence level. Some other rheological parameter or combination of parameters may be better than either kinematic or dynamic viscosities.     

The influence of lubricating oil on deposits formation in a diesel engine under the operation condition of high power density

The requirements of higher power density and stricter regulations on emissions of internal combustion engines lead to lubricating oil's role shifting from simply lubricating to adapting higher power density and to achieving lower emissions. An important factor influencing an engine's power and emissions is the deposits in the engine. Lubricating oil is a chief contributor to deposits formation. The objective of this paper is to investigate the influence of lubricating oil on deposits formation when the engine is operated under high power density. Metal elements content in lubricating oil and changes to power and emissions were measured to verify deposits changes. Different power densities can be achieved by adjusting the fuel supply system in the engine. Three kinds of synthesised lubricating oils were used in the investigation. The temperature of the oil pan and cooling water was strictly controlled. The experimental results demonstrated well the influence of the quality of different kinds of oil on deposits formation. Copyright © 2013 John Wiley & Sons, Ltd.     

新型发动机滑油系统故障预防与分析

主要介绍新型飞机的滑油系统，并结合该型飞机实际工作情况，对滑油系统所产生的故障进行综合分析，提出了一些具体的解决措施。     

The effects of a demulsifier on the interface of marine engine oil and water

The water‐shedding property and the interfacial tension of marine engine oils with various additives have been assessed and analysed in this paper. It is concluded that the weak water‐shedding property was mainly due to the molecular structure and the interfacial property of sulphonate detergent, which can adsorb on the oil–water interface intensely to form a strong interfacial film and prevent coalescence of droplets. The impact of a demulsifier to the water‐shedding property and the interfacial tension indicated that demulsifier improved the water‐shedding property of marine engine oil in the manner of being much easy to adsorb onto the interface but formatting a flimsy interfacial film. Copyright © 2011 John Wiley & Sons, Ltd.     

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.     

柴油机连杆动力学分析的新方法

认为连杆是刚体，作平面运动，手出运动方程；基于刚体平面运动理论，提出一种新的柴油机连杆动力学数值计算方法——转动惯量法；该方法进行连杆动力学分析速度快，计算精度也得到提高；通过证明可以发现“连杆多质量代替法”仅是该方法的一种简化形式。     

Changes in the mechanical properties of oil used in a gasoline engine

This study is concerned with the changes in and deterioration of the mechanical properties of oil used in a gasoline engine. The properties analysed were friction and antiwear performance, wear debris, load-carrying ability and the formation of surface films. It was found that the oil run in an engine deteriorated so as to increase the wear and friction and decrease the load-carrying ability as the running distance of oil was increased. The main cause of deterioration was related to the ability to form a protective film in the contact zone. When the film was produced by additives (sulphur), this could properly protect the surface in the contact zone undepleted from wear and friction. But as the oil deteriorated, it could not form such a film and so its protective ability on sliding surfaces diminished.     

A new method for assessing the lubricating ability of two-stroke engine oil

Evaluating the lubricating ability of two-stroke engine oils in laboratory test machines is difficult because of the lack of correlation with the engine test results. A high speed disc machine has proved its value as an effective screening method for this purpose: this paper describes the technique and its correlation with engine performance     

Influence of oil-soluble copper salts on catalytic oxidation of lubricating oil in laboratory conditions and in a single-cylinder engine

During oxidation of an engine oil under laboratory conditions, and testing in a single-cylinder gasoline engine, it has been found that oil ageing depends on the copper content, in particular the oil-soluble copper salt content. The latter considerably intensifies engine oil oxidation, loss in bearing weight, and piston deposit formation. Several regularities in the oil ageing process were found. It was noted that interaction of copper naphthenate with zinc dithiophosphate essentially influences this process.