GRT节能油添加剂的性能评定

用摩擦磨损试验机和皮特W—1、1105、AV—B等发动机台架试验设备评价了含有GRT节能油添加剂的内燃机油的润滑性能、高温氧化腐蚀性和高温清净分散性。试验表明,加入GRT节能油添加剂后,改善了机油的承载能力,降低了摩擦、对摩件的磨损和高温下的氧化腐蚀,且对机油的高温清净分散性没有影响。实际行车试验表明,使用GRT节能油添加剂可获得节约燃料油7％的效果。     

机油中添加固体润滑剂节约燃料油的研究

本文通过相转移工艺研制了含微细分散石墨,83—21分散稳定剂等的节能油添加剂(GRT节能油添加剂)。 实验室试验结果表明,这种添加剂具有良好的胶体稳定性,在贮存期内不会产生沉降。摩擦磨损试验及负荷承载能力试验说明,在商品内燃机油中加入GRT节能油添加剂之后,摩擦和磨损显著降低,负荷承载能力则明显提高。实际行车试验表明,在汽车机油中加入GRT节能油添加剂之后,可节约燃料油5％以上。 同时还用俄歇能谱仪等分析仪器探讨了GRT节能油添加剂的减摩抗磨机理。     

几种润滑剂的低温分散性能研究

在现代润滑油技术研究中，润滑油的低温分散性能显得特别重要．利用ＤＷＹ－Ｉ型内燃机油低温油泥试验仪对几种矿物基础油、发动机油以及清净分散剂、分散性粘度指数改进剂和复合添加剂的低温分散性能进行了试验研究．结果表明：发动机油的低温分散性能随油品级别的增高而变好；随着清净分散剂添加量的增加，其低温分散性能明显改善；在所评价的酰亚胺类、酯类无灰和双酐无灰等多种分散剂中，以单取代的丁二酰亚胺的分散性能最好     

PG-2齿轮油复合剂的摩擦学性能研究

研制了同商用齿轮油添加剂Hitec343具有相似结构和组成的PG-2复合剂;通过热重分析考察了所研制的PG-2复合剂的热稳定性能;利用红外光谱分析考察了其化学结构特征;采用四球摩擦磨损试验机考察了其极压抗磨性能,并采用扫描电子显微镜分析了钢球磨损表面形貌.结果表明,所研制的PG-2复合剂具有优良的极压抗磨性能、防锈性能、防腐蚀性能及热稳定性,其总体性能同国外同类复合剂产品相当,而极压性能优于国外同类复合剂.     

二烷基二硫代甲酸钼和二烷基二硫代磷酸钼对缸套／活塞环摩擦学行为的影响

在125℃和320℃下,以全配方矿物基SJ／5W—30型发动机油作为基础润滑油,考察了油溶性有机钼添加剂MoDTC与MoDTP对灰铸铁缸套／喷钼活塞环摩擦学行为的影响。结果表明：MoDTC可以改善基础油的减摩抗磨性能,而MoDTP仅表现出一定的抗磨作用;试验温度对缸套-活塞环的摩擦磨损性能具有重要影响,X射线光电子能谱分析表明：缸套磨损表面主要含有铁氧化物、氧化钼、硫化铁、二硫化钼以及磷酸盐等,其含量与添加剂类型和摩擦磨损试验温度有关,125℃下在缸套磨损表面上减摩组分MoS2和其它耐磨组分的含量较高,这是MoDTC具有较好减摩耐磨性能的主要原因。     

氧化铈纳米添加剂与商用添加剂的共吸附行为及其协同润滑机制研究

纳米添加剂因其高效的减摩抗磨效应在节能内燃机油中具有广阔的应用前景,与内燃机油中商用添加剂的协效机制是开发纳米添加剂内燃机油配方的关键问题.本文中利用石英晶体微天平(QCM-D)研究油胺修饰CeO₂纳米微粒与商用内燃机油添加剂在金属表面的协同吸附行为,及其对CeO₂纳米添加剂减摩抗磨性能的影响机制.发现清净剂(DE)、减摩剂(FM)、抗氧剂(AO)和黏指剂(VII)都可以同CeO₂纳米微粒共同形成摩擦膜,使抗磨性能优于单一添加剂,表现出了协同效应. CeO₂纳米微粒与有机分子添加剂复配的抗磨性能与其吸附层的吸附质量成正比.对于趋近于单层刚性吸附的添加剂,随分子中烷基链长度的增大,CeO₂纳米微粒参与共吸附的程度逐渐降低.分散剂中的长烷基链PIB (聚异丁烯)部分阻碍了CeO₂纳米微粒的吸附,使其无法在摩擦副表面沉积成膜,导致了显著的拮抗效应.     

铝板带冷轧过程中磨损影响因素 及磨损作用机制研究

轧后铝材表面磨损量是影响铝材轧制过程的重要因素,脱落的铝粉恶化产品表面质量、影响轧制效率。本文选用不同的添加剂配制轧制油,对铝板材进行冷轧试验,重点研究添加剂种类、铝材原始表面质量、轧制压下率三方面对铝材表面磨损性能及磨损机制的影响。结果表明：双组分添加剂轧制油中油性剂在金属表面吸附成膜,犁削磨损现象较无润滑和纯基础油轧制有明显改善,轧后铝材表面磨损量小;轧件轧前表面粗糙度大,轧辊对轧件微凸体的碾压作用加剧,被碾压下来的大量铝粉成为轧辊和轧件外的“第三体”,造成磨粒磨损加剧;化学磨损和犁削磨损同时存在于轧制过程中,油膜厚度较大时,前者是主要磨损机制;反之,后者起主导作用。     

汽车自动传动液减摩性能研究

采用改进的Falex-Ⅰ型摩擦磨损试验机考察了几种添加剂对汽车传动液的减摩特性影响．结果表明：2．6-二叔丁基对甲酚对汽车自动传动液的减摩性能影响较小，防锈剂、极压抗磨剂、分散剂、抗腐剂及摩擦改进剂等添加剂对油品的减摩性能影响较大；某些摩擦改进剂可以改善汽车自动传动液的摩擦稳定性；汽车自动传动液的减摩特性主要取决于添加剂的平衡关系及添加剂在金属表面的作用．     

合成酯型摩擦改进剂的制备及摩擦学性能研究

通过酯交换以及酯化反应制备了一种新型合成酯型润滑添加剂(SE).采用四球试验机对比考察了SE与甘油单油酸酯(GMO)在聚α烯烃(PAO)基础油以及发动机油中的摩擦学性能.研究了不同添加浓度、载荷和温度对其摩擦学性能的影响规律.结果表明:SE在PAO以及发动机油中均具有良好的减摩、抗磨损性能,其中SE的减摩性能优于GMO而抗磨损性能则相反,同时对SE与GMO在PAO中的摩擦学机理进行了探讨.加压差示扫描量热试验表明由于受阻酚官能团的存在,SE在PAO以及发动机油中均表现出一定的抗氧化性能.     

聚四氟乙烯型减摩剂减摩与抗磨效果的评定

含胶体聚四氟乙烯的减摩剂是国外近年研制的一类应用于汽车发动机润滑的新型润滑材料。本文主要介绍了用国产多缸汽油机评定三种美国减摩剂和一种国内研制的产品的减摩节油效果,以及这些减摩剂在国产汽油机上使用的抗磨效果。 试验按统一方法,分别在北京、上海、广东三个地方进行。各地各种评定方法取得的试验结果,相关性较好,证明此类减摩剂在国产汽油机上使用有减摩、抗磨效果,等速燃料消耗降低了4％左右;运行百公里节约燃油3％左右,发动机气缸磨损减少10％～40％。     

国外甲醇发动机磨损研究的概况

本文对国外10多年来甲醇发动机磨损研究的概况作了综述介绍,指出甲醇发动机发生的是腐蚀磨损,其活塞环和气缸壁上部区域的磨损最严重;甲醇燃料燃烧产物中的甲酸、水及其所含的剩余甲醇是引起甲醇发动机腐蚀磨损的重要物质,过氧化氢促进着这种腐蚀磨损过程。文章还就如何有效地解决甲醇发动机的腐蚀磨损问题进行了初步探讨,提出了应当着重开展的研究工作方向。     

内燃机磨合与表面改性实验研究

针对EQ6100型汽油机,利用内燃机磨合台架试验装置对所研制的内燃机专用磨合油与普通15W／40内燃机油进行对比磨合试验,对磨合油液进行直读铁谱分析,对缸套－活塞环磨合表面形貌及元素组成进行测试分析。结果表明：专用磨合油的磨合效果明显优于普通内燃机油;超细金刚石微粉可以加速磨合进程,分化并减小磨屑尺寸,从而避免缸壁拉伤和改善缸套－活塞环摩擦副的摩擦学特性。     

纳米金刚石颗粒对发动机润滑油摩擦学特性的影响

采用爆炸法合成了超精细金刚石颗粒 ,将金刚石颗粒按一定质量分数分散于普通发动机润滑油 (15W/30 )中形成固 -液二相体系 ,考察了其摩擦学特性 ,并分析了润滑剂的减摩抗磨作用机理 .结果表明 ,在边界润滑条件下 ,由于纳米尺寸效应 ,超精细金刚石颗粒较易渗透到摩擦副表面并形成极薄的固体润滑膜 ,从而使得金刚石颗粒 /发动机润滑油固 -液二相体系表现出优异的承载能力和减摩抗磨性能     

燃油稀释对柴油机油性能影响规律研究

以CK-4 15W40柴油机油为基础油,通过添加不同比例(质量分数分别为5%、10%、15%和20%)的0#柴油制备了不同燃油稀释比例的柴油机油,对稀释油品的基本理化性能(黏度、倾点、闪点和酸碱值)进行了测试. 采用曲轴箱模拟试验仪、加压差示扫描量热试验仪、点接触光弹流润滑试验台以及SRV试验机对稀释前后油样进行了结胶性能、抗氧化性能、弹流润滑以及边界润滑性能进行了研究. 结果表明:燃油稀释后的柴油机油黏度和闪点明显下降,倾点未发生明显变化,酸碱值和抗氧化性能有一定程度的降低. 弹流润滑条件下发动机油的油膜厚度降低,同时燃油稀释后柴油机油在边界润滑条件下的减摩与抗磨性能有所下降.      

Heat flux characteristics of spray wall impingement with ethanol,butanol, iso-octane,gasoline and E10 fuels

Future fuel stocks for spark-ignition engines are expected to include a significant portion of bio-derived components with quite different chemical and physical properties to those of liquid hydrocarbons. State-of-the-art high-pressure multi-hole injectors for latest design direct-injection spark-ignition engines offer some great benefits in terms of fuel atomisation, as well as flexibility in in-cylinder fuel targeting by selection of the exact number and angle of the nozzle’s holes. However, in order to maximise such benefits for future spark-ignition engines and minimise any deteriorating effects with regards to exhaust emissions, it is important to avoid liquid fuel impingement onto the cylinder walls and take into consideration various types of biofuels. This paper presents results from the use of heat flux sensors to characterise the locations and levels of liquid fuel impingement onto the engine’s liner walls when injected from a centrally located multi-hole injector with an asymmetric pattern of spray plumes. Ethanol, butanol, iso-octane, gasoline and a blend of 10% ethanol with 90% gasoline (E10) were tested and compared. The tests were performed in the cylinder of a direct-injection spark-ignition engine at static conditions (i.e. quiescent chamber at 1.0 bar) and motoring conditions (at full load with inlet plenum pressure of 1.0 bar) with different engine temperatures in order to decouple competing effects. The collected data were analysed to extract time-resolved signals, as well as mean and standard deviation levels of peak heat flux. The results were interpreted with reference to in-cylinder spray formation characteristics, as well as fuel evaporation rates obtained by modelling. In addition, high-speed images of single droplets of fuel impinging onto the array of the heat flux sensor were acquired with simultaneous sampling of the heat flux signal in an attempt to provide further interpretation. The single droplet tests showed ability of the signals to quantify droplet mass impinged on the sensor. Analysis of the peak heat flux at static engine conditions quantified values of fuel temperature at impingement in agreement with the wet bulb temperatures predicted by the droplet evaporation model. Comparison of the static and motoring engine heat flux signals around the bore showed the effect of the intake flow on the spray’s pattern at impingement and demonstrated fuel presence on the liner that survived at exhaust valve open timing. The general behaviour was different for the alcohols to that of the hydrocarbons, with ethanol exhibiting the effect of its high latent heat on the signals and butanol exhibiting effects related to poor atomization and slow evaporation.     

Evaluation for energy-saving effect of hybrid drilling rig system based on the logic threshold method

A simulation model of the current rotary drilling rig (RDR) system was built according to the basic configuration of the TR160D-type rotary drilling rig, and the test-rig based on the working principle of the RDR system was built. The results show that simulation model of the RDR system was accurate and reasonable by means of comparative analysis between theoretical computation and test data. The working principle and logic threshold control method of the HDR system were presented to reduce the fuel consumption and improve energy-saving efficiency via the analysis of energy flow of the RDR system, which mainly includes engine, electric motor/generator, super capacitor, AC–DC rectifier/DC–AC inverter and torque coupler, etc. Finally, the comparative analysis of the fuel economy between the RDR and the hybrid drilling rig (HDR) system was completed in the same overall typical operating conditions. The results show that energy-saving efficiency of HDR system is at 18.8% and total fuel economy efficiency of HDR reaches 15.9% relatively in a typical operating condition.     

A contribution to film coefficient estimation in piston cooling galleries

The need to reduce fuel consumption and exhaust emissions in internal combustion engines has been drastically increased during last years. One of the most important processes affecting these parameters is heat transfer from the in-cylinder gas to the surrounding walls, as this mechanism has a direct influence on the combustion process. Regarding the different walls (liner, cylinder head and piston surfaces), heat flow to the piston is especially important, as it is essential to avoid excessively high temperatures that could result in material damage and/or oil cracking. With this purpose different cooling strategies are used, among which the improvement of the piston cooling system by using oil galleries is preferred. In this work, the heat flow through the oil gallery in a Diesel piston was investigated on a dedicated test bench. This bench consists of a controlled heat source and a piston oil cooling system in which different test conditions were evaluated in order to obtain a correlation for the film coefficient associated with piston oil cooling. These experimental results were then incorporated into a lumped model for engine heat transfer. Finally, in order to evaluate the accuracy of this model and the effects of the correlation for oil gallery coefficient on engine heat flows, results obtained on a conventional engine test bench equipped with a Diesel engine, in which two piston temperatures had been measured, were used. The results show an improvement in piston temperature predictions when compared with those obtained using a previously reported expression for the calculation of the oil film coefficient.     

In-cylinder fuel distribution in a port-injected model engine using Rayleigh scattering

The spatial and temporal variation of the fuel concentration (air/fuel ratio) in a model engine was quantified by laser Rayleigh scattering. Fuel was simulated by gaseous Freon-12 injected at various timings and quantities into the intake port. The results showed that the fuel concentration in the engine cylinder was strongly dependent on the injection timing and duration and that the Rayleigh system was able to identify spatial variations of the order of one air/fuel ratio at realistic mixture strengths.     

可聚合添加剂和极压添加剂对矿物油极压抗磨和抗疲劳性能的影响

选用重极压齿轮油和二聚酸 /司本 - 80添加剂制备了多种不同配比的油样 ,进行了疲劳和胶合试验 ,同时分析了磨损表面形貌和抗磨机理 .结果表明 :聚合添加剂的耐疲劳性能较好 ,其与极压添加剂经合理复配可以更好地提高油样的耐疲劳及抗胶合综合性能 .这是两类添加剂协同作用的结果     

Measurements of ultrafine particles from a gas-turbine burning biofuels

Measurements of ultrafine particles have been performed at the exhaust of a low emission microturbine for power generation. This device has been fuelled with liquid fuels, including a commercial diesel oil, a mixture of the diesel oil with a biodiesel and kerosene, and tested under different loads. Primarily attention has been focused on the measurements of the size distribution functions of the particles emitted from the system by using particle differential mobility analysis. A bimodal size distribution function of the particle emitted has been found in all the examined conditions. Burning diesel oil, the first mode of the size distribution function of the combustion-formed particles is centered at around 2–3 nm, whereas the second mode is centered at about 20–30 nm. The increase of the turbine load and the addition of 50% of biodiesel has not caused changes in the shape of size distribution of the particles. A slightly decrease of the amount of particle formed has been found. By using kerosene the amount of emitted particles increases of more than one order of magnitude. Also the shape of the size distribution function changes with the first mode shifted towards larger particles of the order of 8–10 nm but with a lower emission of larger 20–30 nm particles. Overall, in this conditions, the mass concentration of particles is increased respect to the diesel oil operation. Particle sizes measured with the diesel oil have been compared with the results on a diesel engine operated in the same power conditions and with the same fuel. Measurements have showed that the mean sizes of the formed particles do not change in the two combustion systems. However, diesel engine emits a number concentration of particles more than two orders of magnitude higher in the same conditions of power and with the same fuel. By running the engine in more premixed-like conditions, the size distribution function of the particles approaches that measured by burning kerosene in the microturbine indicating that the distribution function of the sizes of the emitted particles can be strongly affected by combustion conditions.