一种新型船用柴油机油的研制

根据船用柴油机油的性能要求,通过开展基础油及各功能添加剂等对油品抗水、分水性能的影响研究,以及清净分散剂、抗氧抗磨剂等添加剂对油品高温清净性、烟炱分散性、抗磨损性及抗氧抗腐蚀性的影响研究,提出一种新型船用柴油机油配方方案。综合评定试验结果表明,研制的船用柴油机油具有优异的理化性能和良好的分散性、抗氧抗腐蚀性、抗磨性能和清净性能,并通过了FZG齿轮试验机试验和发动机台架试验。     

The Role of Soot Aggregation on the Lubrication of Diesel Engines

This paper deals with the role of the soot on the valvetrain wear in diesel engines. First, wear is related to the soot aggregation at the inlet, of the cam-tappet contact. Then, an experimental device using a Rayleigh pad which allows one to study the aggregation underflow of diesel soot in completely formulated oils is described. The results concerning four oil samples, chosen for their differences in formulation and aging are given and related to the wear. Finally, the aggregation is related to the interparticle interactions and, more particularly, to the dielectric constants of the soots and of the lubricant.     

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.     

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.     

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。     

柴油机油烟炱分散性能研究

通过模拟试验、发动机台架试验以及行车试验,考察柴油机润滑油的烟炱分散性能。结果表明:烟炱模拟试验能区分不同油品的烟炱分散能力;由于发动机技术的不同、试验目的的不同、试验条件设置的不同,台架试验结果会有很大差异,应根据发动机的技术特点,建立与润滑油在车辆实际使用过程中性能相关联的台架试验;质量级别越高的润滑油,其烟炱分散性能越好;不同分散性能、不同类型黏度指数改进剂的润滑油在行车试验中性能差异不大,特别是由烟炱引起的黏度变化基本没有表现出来,而黏度指数改进剂的剪切性能对黏度指标的影响比烟炱含量的影响表现得更为突出。     

Role of thermal,mechanical and oxidising treatment on structure and chemistry of carbon black and its impact on wear and friction Part I: Extreme pressure condition

Carbon black was blended in different oil formulations that included base oil with ZDDP and dispersant as well as fully formulated oils. The blended formulations were then subjected to various thermal, oxidative and mechanical treatments to force interaction between the carbon black and different constituents of the oil and thermo-oxidative decomposition products of oil. Wear studies conducted on the treated compositions were compared with formulations that were blended with extracted diesel soot. XANES analysis of extracted diesel soot and treated carbon black were compared to elucidate similarities between the two in terms of their chemical constituents. Tribological and XANES results indicate that it is possible to simulate wear conditions similar to those seen with diesel soot when appropriate thermo-oxidative conditions were used.     

Effect of Bio-Lubricant and Biodiesel-Contaminated Lubricant on Tribological Behavior of Cylinder Liner–Piston Ring Combination

This article addresses the issue of friction and wear characteristics of diesel engine cylinder liner–piston ring combinations under different lubricating conditions using a pin-on-disc wear tribometer. The discs were made out of actual engine cylinder liner material using a casting process. Pins were made out of top compression ring material. The tests were conducted on a pin-on-disc tribometer for wear and friction characteristics of the cylinder liner and piston ring combination with diesel-contaminated rapeseed oil–based bio-lubricant, diesel-contaminated commercial synthetic lubrication oil (SAE 20W40), biodiesel-contaminated commercial synthetic lubrication oil (SAE 20W40), and used (150 h) commercial synthetic lubrication oil (SAE 20W40). Experimental results demonstrated that the rapeseed oil–based bio-lubricant and biodiesel-contaminated synthetic lubricant exhibited better performance in terms of wear, friction, and frictional force under similar operating conditions. Thus, usage of newly formulated bio-lubricant and biodiesel in the long run may have a positive impact on engine life.     

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.     

Role of thermal,mechanical and oxidising treatment on structure and chemistry of carbon black and its impact on wear and friction: Part 2 – Boundary lubrication condition

Mineral oil formulations with zinc dialkyl dithiophosphate (ZDDP) and dispersant (poly isobutylene succinimide ashless dispersant or ‘PIBSA’) and fully formulated oils with and without carbon black were subjected to thermal and mechanical treatment and tribologically tested on TE 77 (high frequency reciprocating rig or ‘HFRR’) machine to examine the frictional performance during the test. These results were compared to oils without carbon black and oils with diesel soot. Results indicate that oils with just ZDDP and dispersant had the highest friction that remains constant for the duration of the test while oils with carbon black in the milled and oxidised condition had the lowest coefficient of friction and the smallest surface roughness in the tribofilm. The mechanism of wear with treated carbon black and diesel soot was found to be polishing wear as evidenced by the scanning probe microscopy images of the tribofilms. Tribofilms were analysed with X-ray absorption near edge structure (XANES) and it was seen that oils without carbon black or even with untreated carbon black had sulphates at the surface, while the oils with carbon black that were treated had a higher proportion of sulphides. A combination of both FeS and ZnS was found in the tribofilms along with short chain phosphates of Zn.     

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.     

The Behavior of Diluted Sooted Oils in Lubricated Contacts

An increase in the engine lubricant soot levels has recently been noticed. This increase in soot content of lubricating oils has caused a series of problems in the overall performance of the engine. In a practical context, sooted oils consist of carbonaceous matter suspended in engine oil forming a system commonly known as a colloid sol. The objective of this paper is to better understand the mechanism of action of oil containing soot particles in the lubricated contacts and to identify how the colloidal nature of the sooted oil is related to its performance. This study has shown by means of ultra-thin film interferometry and image analysis techniques that soot colloid particles are entrained in the contact inlet where they can influence the friction and wear characteristics of the base stock. This study shows that soot primary particles are entrained into the contact at slow speeds, affecting the film characteristics of clean engine oils. This entrainment of particles is more pronounced at high temperatures.     

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。     

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.     

The 2D measurement of soot diameter and number density in a diesel engine using laser induced methods

It is necessary to diagnose accurately the characteristics of soot formation and oxidation in a diesel engine. Whereas past measurement techniques for soot concentration give limited information for soot, laser-based two-dimensional imaging diagnostics have a potential to provide temporally and spatially superior resolved measurements of the soot distribution. The technique using laser sheet beam has been applied to an optically accessible diesel engine for the quantitative measurement of soot. The results provided the information for reduction of soot from the diesel engine. Both LIS (Laser Induced Scattering) and LII (Laser Induced Incandescence) techniques were used simultaneously in this study. The images of LIS and LII showed the quantitative distribution of the soot concentration in the diesel engine. In this study, several results were obtained by the simultaneous measurements of LIS and LII technique. The diameter and number density of soot in combustion chamber of the test engine were obtained from ATDC 20 degree to 110 degree. The soot diameter increased about 37% between ATDC 20 degree and 110 degree. The number density of soot, however, decreased significantly between ATDC 40 degree and 70 degree.     

船用中速机油使用性能的评定方法

通过对船用中速机油的现有台架进行改造,增加润滑油净化系统,建立了船用中速机油使用性能评定方法。该方法可模拟船舶发动机实际使用情况,考察船用中速机油受水污染后的碱值衰变、分水性能、活塞清净性及抗磨损等实际使用性能。通过对几种船用中速机油的评定试验表明,选择的试验条件合理,该评定方法可以满足评价油品综合性能的要求。     

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.     

Composition and oxidation stability of SAE 15W-40 engine oils

The modified IP 48 procedure was used for testing the oxidation stability of engine oils for ignition engines of the SAE 15W-40 and minimum API SG/CD specifications. Eight engine oils, such as Agip, BP, Esso, Mogul, ÖMV, Petro-Canada, Shell, and Total, were collected and oxidised. Oils were also fractionated by using chromatographic methods, and group composition of base oils, amount of VI improvers and other additives were determined. Several differences in the oxidation stability were found between the collected oils. Viscosity characteristics, carbon residue, acid number, amount of pentane insolubles and mass losses during the test were chosen as parameters for evaluation of the oxidation stability of the oils. The most stable engine oil was blended from a hydrocracked base oil whereas most of the other oils were based on the solvent refined oils.     

15W/40 CF-4高档柴油机油的研制

本文主要介绍了以清净剂、分散剂以及抗氧抗腐剂为主要原料，通过对各添加剂之间复合规律进行详细的考察后，以12．5％的加剂量应用于加氢基础油中调制的15W／40CF—4柴油机油，通过了Caterpillar IK以及L-38台架试验。     

Characteristics of diesel engine soot that lead to excessive oil thickening

This is a study of soot from a heavy duty diesel (HDD) engine test designed to evaluate the soot handling ability of a lubricant. This study aims to understand what properties of diesel soot produced under certain conditions contribute to loss of viscosity control through examination of the morphology, nanostructure and oxygen functionalization of particulates obtained from two heavy duty diesel engine tests with different levels of EGR. Particulate samples obtained from the used engine oil that lost viscosity control at relatively low soot levels showed that the soot in this case was more graphitic and had lower oxygen functionalization.