内燃机润滑油过量消耗的原因分析及对策

内燃机润滑油过量消耗的原因分析及对策冯长征，侯宪春，侯兆安润滑油过量消耗或过早变质失效，这样不仅不经济，而且还会导致内燃机零部件严重磨损和早期损坏等事故。因此，保持内燃机润滑油适量的消耗，是持续发挥发动机性能的必要条件，是延长其使用可靠性的重要保障。...     

船舶内燃机润滑油质量的人工鉴别与正确使用

分析了船舶内燃机润滑油劣化的主要因素及对设备的影响，详细介绍了润滑油的人工鉴别和正确使用方法。     

天然气汽车专用发动机润滑油研究

天然气作为汽车燃料能显著减少排放污染，并具有良好的经济性，但汽车使用天然气作燃料时，会导致发动机功率下降和严重的早期磨损。为适应发动机使用天然气的特点，专门研究了天然气内燃机润滑机，该润滑油经实验室性能评定、模拟试验、发动机台架试验和汽车道路对比试验。     

车用内燃机润滑油质量的鉴别与正确使用

针对内燃机润滑油变质的原因，介绍了鉴别润滑油质量的几种实用方法，总结了车用汽、柴油机润滑油的正确选用和更换注意事项。     

润滑油在内燃机管道内的流动特性研究

润滑油在内燃机管道内的流动状况将影响润滑系统的工作性能.根据润滑油在内燃机管道中流动情况,研制了用于测量管道内润滑油流动特性的专用试验装置.并结合实际管道及相应的试验数据,对目前内燃机润滑系统网络法分析中用于描述润滑油在管道内流动特性的几种简化计算方法进行了对比分析.研究结果表明,利用简化计算方法来设计分析内燃机润滑系统是偏安全的.其中,利用Blasius公式形式最简单,且计算结果最接近实测值.     

机油增效剂的作用机理及试验研究

随着内燃机的强化，良好的润滑成为一关键问题。本文通过在润滑油中加入添加剂的对比试验，分析出提高油品质量和改善内燃机各项性能的途径及方法。     

应用神经网络对润滑油抗氧性的分析

本文采用神经网络辅助分析的方法，对内燃机润滑油的抗氧化性做了分析，对内燃机油中ZDDP的加量对润滑油抗氧性的影响作了预测，并将神经网络输出结果与实验结果进行比较，使网络训练误差得到最小．使网络训练结果与实验结果得到较好的模拟。     

常见的内燃机使用误区

内燃机使用不当,是目前造成其早期损坏和使用可靠性降低的重要因素之一。本文对内燃机实际工作中常见的几个使用误区及危害作一介绍,同时提出了预防方法和使用注意事项。 1.循环加注润滑油或以不同品质的油掺兑使用 循环加注润滑油,是指在加注润滑油时不定期换油、不     

润滑管理(三)

①润滑油粘度问题的重要性有些人认为内燃机润滑油是粘度越大越好,这是不正确的,当然粘度少了也不行,必须适当。目前世界上各个工业发达国家所使用的内燃机润滑油都倾向于低粘度加抗磨添加剂,如日本近年生产的省能润滑油就是这样。根据流体力学、润滑的理论及实践证明,当油膜厚度δ>0.6μm时,润滑油膜符合于流体润滑的理论,则摩擦阻力决定于润滑油膜的内摩擦,因此动力损失大小也就取决于润滑油的粘度。内燃机的正常运行,必须保证各摩擦副得到充分的液体润滑,才能保证变摩擦副表面金属的固体摩擦为润滑油液体摩擦,而要保证得到液体润滑,润滑油的粘度问题,就成为     

新能源汽车与内燃机的汽车噪声特性分析

随着国内社会经济的迅速发展，对汽车领域提供了很大的发展空间，特别是新能源汽车与内燃机汽车方面。但随之带来了些许问题，如汽车噪音很影响行人安全等。为解决该问题的出现，本文以新能源汽车、内燃机汽车等在国内外发展现状以及车辆行驶过程中产生的噪声问题为研究对象。先简单概述了内燃机汽车与新能源汽车，接着对4种不同类型的车辆行驶所产生的噪声问题及原因进行分析，根据不同的速度变化对造成汽车噪声可能存在的变化角度进行分析，判断不同类型汽车之间所产生的噪声差异。     

两种不同润滑添加剂对车用二甲醚发动机性能影响的试验研究

开展了两种润滑添加剂对二甲醚发动机燃烧与排放特性影响的试验研究。结果表明:分别加入C100和R100这两种润滑添加剂后二甲醚发动机均可在宽广的转速和负荷范围内工作,其输出功率都可达到甚至超过原柴油机,但加入润滑添加剂R100时二甲醚发动机的输出功率、缸内最高爆发压力和最大压力升高率比加入润滑添加剂C100时的略高;加入两种不同润滑添加剂后二甲醚发动机都可以实现无烟燃烧,NOx、HC和CO排放相当。     

基于油液分析的汽车发动机摩擦系统故障诊断专家系统知识库的建立

采集汽车发动机润滑系统中摩擦副经历磨擦学行为的信息是诊断发动机摩擦系统故障的有效手段。油液分析从摩擦学系统的润滑剂和磨损物两方面获得磨擦副的润滑和磨损状态的信息。但常规的油液分析信息处理方法上的不足影响了油液分析技术在汽车行业的实际应用,开发基于油液分析的故障诊断系统,无疑会改善油液分析的诊断准确性和诊断成本。本文着重针对该诊断专家系统知识库的建立,     

A Chemical Kinetics Model to Predict Diesel Engine Performance. Part II. Bench-Test Procedures

Bench tests have been used to screen lubricants and additives for industrial fluids in machinery applications for a long time. As the cost of engine testing increases dramatically, the need for simple laboratory bench tests increases. Bench tests simulate a particular aspect of the engine operation such as oxidation or wear, but the engine operation blends both mechanical, chemical, and combustion processes together and allows these parameters to interact freely. There are many bench tests providing a measure of oxidation stability under simulated conditions. For a given application, while the generic aspects of the lubricant degradation mechanism may be similar, environmental factors such as oxygen availability, the presence of specific metals (catalytic effects), and residence times of the oil at high-temperature regions may be specific to that application. Universal bench-test procedures that can predict oxidation stability therefore are not feasible. As described in part I of this paper, a computer simulation program has been developed combining a chemical kinetic model and a finite-difference program to simulate the engine operating conditions to predict lubricant performance in a diesel engine. This paper describes the bench-test procedures used to determine the kinetic constants used in the kinetic model to describe the lubricant degradation processes. The bench tests are specifically designed for the determination of kinetic constants in general for a particular reaction path but take into account the particular environmental factors intrinsic in the Caterpillar 1K engine dynamometer test.     

Advanced lubricants for heat engines

An advanced liquid lubricant for heat engines has been developed and tested successfully in a prototype engine. The lubricant possesses superior oxidation stability and high temperature stability. With the advent of new engine designs, stability should be measured in terms of both the temperature and the time for which the lubricant is subjected to it. This lubricant is designed to provide friction and wear protection for three to five minutes at 425°C (800°F) at the ring zone and maintains stability at an oil sump temperature of 171°C. The lubricant has been evaluated by the Cummins Engine Company. Out of a field of several dozen lubricants, six lubricants were selected for a prototype 200 h endurance tests. The NIST lubricant was one of the two lubricants that successfully finished the endurance testing. This paper provides an overview of the key lubricant design considerations, including oxidation and thermal stability, volatility, and deposit control, the prototype engine test conditions and the results.     

Research on an on-line wear condition monitoring system for marine diesel engine

This paper introduces a kind of on-line wear condition monitoring system for marine diesel engines. The system consists of three functions i.e. particle detecting, lubricant quality detecting and shaft torque moment and instantaneous rotation velocity detecting. The system detects wear particles in lubricant with an on-line ferrograph so as to judge wear condition of tribo-pairs of the diesel engine. A vertical detector fixed is used for environment of the marine diesel engine in this system, and the rule of distribution of particles in the vertical detector fixed and the horizontal detector fixed are alike in substance. The system detects the relative variation of lubricant quality by the grid capacitance sensors in an on-line way, which consists of an upper capacitance and a lower capacitance and can distinguish the relative variation of the dielectric constant of lubricant caused by pollutants such as water, metal particles etc. The system detects the shaft torque moment and the instantaneous rotation velocity of the diesel engine with photoelectric sensors, and corresponds the wear condition with the power condition by the change of instantaneous rotation velocity due to burning pressure change, which is helpful to judge cylinder wear.     

纳米TiN对润滑油性能的影响及其在柴油发动机上的应用

控制纳米TiN添加量处于0.25%~1%范围内,利用MRS-10A四球摩擦试验机研究其对润滑油性能的影响。利用磨斑测量系统、激光共聚焦扫描显微镜OLS  1100和EDX能谱仪测试分析含纳米TiN润滑油的摩擦磨损及修复性能。在柴油发动机试验台上考察含有0.5%纳米TiN的润滑油对发动机运转性能的改善,在不同转速条件下检测润滑油添加剂对发动机外特性的影响。试验结果表明：含有0.5%纳米TiN的润滑油比基础油的抗磨减摩及自修复性能更好。纳米TiN润滑油添加剂能显著提高润滑油质量,减小发动机摩擦功,降低机油温度,改善发动机的运转性能,提高发动机的功率和转矩,降低耗油率,从而达到延长发动机的使用寿命和节约能源的目的。     

Selectivity of the Oxidative Attack on a Model Ester Lubricant

The relative oxidative attack at the various carbon-hydrogen bonds of the model ester lubricant neopentyl hexanoate at temperatures 150–200 C was determined by GLC analysis of appropriate derivatives. Relative rates for single carbon-hydrogen bonds were: primary I,“normal” secondary 15, alpha-acyl secondary 2, and alpha-alcohol secondary 4. These results may furnish valuable insight in the development of more oxidatively stable esters for use in high-temperature jet engine lubricants.     

The Friction Behavior of Individual Components of a Spark-Ignition Engine During Warm-Up

The research presented herein fills a void in the published literature through investigation of transient friction contributions by individual internal combustion engine components during simulated engine warm-up. Currently, engine manufacturers design internal combustion engines primarily for use at steady-state operating conditions with little design consideration for transient engine warm-up. Using the motoring torque waveform and cycle-averaged data of a spark-ignition internal combustion engine, the present work determined the friction behavior of individual engine component assemblies, including the valve train, pistons and connecting rods, oil pump, and crankshaft of a modern internal combustion engine. A common criticism of the standard motoring method is that the engine does not warm up, so lubricant temperature and viscosity does not model that of a fired engine. In the present study, the lubricant and coolant were warmed from 25 to 85°C. Observations were presented as to the effect of engine speed and the temperature of the coolant and lubricant on total engine friction. Contributions of individual engine components to total engine losses were examined, as well as their variation with engine temperature. The added knowledge of the transient effects of engine temperature can help future designers to mitigate friction and component wear, thus improving overall maintenance costs, specific fuel consumption, and emissions.     

Development of engine crank-case oil formulations for oxidation stability using indigenously blended lubricant base-stocks

With changing engine design putting more emphasis on fuel economy, emissions control and low engine oil consumption, the quality levels of engine crank-case oils are changing fast. With this in view, experimental work has been carried out towards the development of engine crankcase-oil formulations meeting the required levels of oxidation stability. Three lubricant base-stocks meeting the physico-chemical characteristics of engine oils, prepared from lubricant streams obtained from different refined crude oils and one re-refined engine oil base-stock were used. The viscosity index of these base-stocks ranged from 84 to 98, and carbon residue from 0.06 to 2.2. The antioxidant used in the formulation was of ZDDP type, and the detergents were calcium and barium sulphonates. The base-stocks were evaluated using the IIP oxidation stability test, to determine their suitability in the formulation of engine crankcase oils. The base-stocks were then dosed with additives, and tested again by the IIP Oxidation Stability Bench Test, for their additive response. The final formulations were then tested on a CRC-L-38 standard engine test prescribed in Indian Standard 13656:1993 for IC Engine Crankcase Oils with respect to bearing corrosion and piston deposit tendencies. It was observed that higher VI lubricant base-stocks and the re-refined engine oil base-stock gave better test performance in both bench and standard engine tests.     

A Chemical Kinetics Model to Predict Lubricant Performance in a Diesel Engine. Part I: Simulation Methodology

The ability of a lubricant to protect increasingly complex diesel engines directly affects engine durability and warranty costs and is becoming increasingly costly to validate. This paper presents a novel approach combining a chemical kinetic model using rate constants determined by a set of laboratory bench tests and a finite-difference computer program to predict lubricant performance in a given diesel engine. The computer program takes into account the engine's mechanical design, such as temperature, pressure, oil flow rate, top ring zone volume, and other parameters. The chemical kinetic model incorporates the kinetic rate constants determined for that particular lubricant in a set of special bench-test procedures tailored to a particular engine and its operating conditions. The bench-test procedures take into account the necessary environment in that particular engine such as specific metal catalysis, oxidation conditions, and deposit formation. The computer program then combines the lubricant degradation model with the engine operating sequence to yield a predictive simulation. This approach is capable of predicting the amount of deposit in the top ring groove and the amount of oil consumption in that engine. The computer program models the engine as three chemical reactors in series. The three reactors are: the oil sump, the top piston ring groove, and the piston cylinder-liner interface. Oil flows from the sump to the piston rings and to the piston liner area. The oxidation process is described by a set of simplified chemical kinetic rate equations. The kinetic constants of the lubricant are determined by laboratory bench-test procedures using Differential Scanning Calorimetry (DSC), a Thermal Gravimetric Analyzer (TGA), and the Micro-Oxidation test apparatus. The design and the operating conditions of the engine define the chemical reaction conditions used in the simulation program such as the temperatures of the reactions, the residence time in a particular reactor, the volume of the reactors, and the operating sequence of the engine. The simulation program is validated by the Caterpillar 1K engine dynamometer test results. Two experimental high-temperature lubricants and three IK reference oils were used in this study. Good agreement between model simulation and 1K engine test results was obtained.