内燃机油总碱值快速分析新技术

介绍了用伏安法快速测定内燃机油总碱值新技术,并将伏安法测定结果与标准方法测定结果进行了比较。研究结果表明采用伏安法测定内燃机油总碱值是可行的,该方法具有快速、简便、误差小等优点,由于测试中不需要人为判定终点,因此,该方法能够实现全自动分析。     

润滑油酸值测定结果影响因素的分析

润滑油的酸值和酸度是表明油品中含有机酸性物质的重要指标。根据酸值的大小,可以判断油品中所含酸性物质的量,油品中的酸性物质的数量随着原料与油品的精制、清洗处理的程度而变化。因而准确测定润滑油中酸值对生产装置具有非常重要的现实意义。润滑油的酸值测定一般借鉴GB264--83石油产品酸值测定法。现从测定的方法原理入手,探讨了影响测定结果准确度与精密度的因素。     

基于电位突跃的润滑油酸值测定方法

目前石油及产品酸值GB/T7304检测方法对使用过的润滑油滴定几乎无电位突跃,需使用毒性大的非水缓冲溶液指示终点.提出了一种基于电位突跃的润滑油酸值测定方法,该方法采用与溶剂相溶性较好且碱度更强有机碱氢氧化季铵盐作滴定剂,通过增加溶剂中醇比例,同时以碱性试剂替代水增强弱酸性物质的表观酸度, 使滴定终点识别完全基于电位突跃,适合各种类型润滑油酸值准确测定.     

光电指示终点微库仑法测定石化产品的酸值和酸度

用光电指示终点的微库仑法测定石化产品酸值和酸度.该法不需要制备和标定滴定剂、操作简便、快速、精密度高、而且节约大量溶剂,值得推广.     

光电指示终点微库仑法测定食用油的酸值

提出了一种光电指示终点的微库仑法测定食用油酸值的方法。该法不需要制备和标定滴定剂、操作筒便、快速、精密度高、而且节约大量溶剂,可以为地沟检测提供借鉴。     

加氢汽油中总氮含量的测定

介绍了化学发光法测定石油中总氮的原理,结合实际经验,讨论加氢汽油中总氮含量的测定条件及操作技巧。采用化学发光定氮法测定加氢汽油中总氮含量的方法分析简单、快速、准确。     

线性扫描伏安法检测润滑油中抗氧剂含量的研究

润滑油中抗氧剂含量决定着润滑油的剩余寿命,研究一种抗氧剂含量快速、简便的测量方法对于润滑油研究十分重要。研究线性扫描伏安法测定润滑油中抗氧剂含量的原理和方法,基于普林斯顿电化学工作站,探讨电解质溶液和扫描速率对测量体系中抗氧剂产生特征伏安峰的影响。结果表明,扫描速率为5 mV/s时,酚类和胺类抗氧剂在含有十二烷基磺酸钠、乙醇和硫酸的电解质溶液中都出现了特征伏安峰,并且抗氧剂的特征伏安峰高与抗氧剂浓度显示出正相关趋势,表明采用线性扫描伏安法测定润滑油中抗氧剂含量是可行的。线性扫描伏安法快速简便,可用于合成油和矿物油中抗氧剂含量的测定,该方法在合成油和矿物油中T501抗氧剂随着老化时间的延长而不断消耗的表征中取得良好效果     

红外光谱法在润滑油分析中的应用与研究进展

综述了红外光谱法在润滑油分析和监测方面的应用与研究进展,重点介绍了近年来该方法在润滑油总酸值、总碱值和水含量方面的应用和研究情况,分析了该方法用于润滑油分析的优势和需要解决的问题,展望了该方法在我国润滑油分析中的应用前景。     

初始pH值复原法测定油品酸值

提出一种初始pH值复原法测定油品酸值方法。在含有0.05 mol/L N-甲基二乙醇胺和0.02 mol/L硝酸钾的体积比为1∶1的水/异丙醇溶剂中,预调初始pH值至11.30～12.30;室温下将油样加入水/异丙醇溶剂中搅拌3 min,其中的酸性物质被萃取,导致pH值下降;由碱标准溶液滴定使pH值复原至初始pH值,由碱标准溶液的滴定体积计算油品酸值。该方法克服了GB/T264方法的需要加热回流和难用于深色油品测定的缺陷,实际样品平行结果相对误差不大于5.26%,与GB/T7304或GB/T264法数据相吻合,为油品酸值提供了一个快速简便的测定选择。     

实际工况下红外光谱法测润滑油总酸值的研究

针对实际工况下采集的在用润滑油,依据ASTM标准试验方法与条件,采用傅里叶红外光谱法与自动电位滴定法分别测得氧化度与总酸值,并研究得到二者之间的相关关系模型。结果表明:从整体上看氧化度与总酸值高度相关,说明用红外光谱测定的氧化度代替电位滴定法测定的总酸值是可行的。但不同类型的油品总酸值与红外氧化度之间的关系存在较大差异,以氧化度理论计算总酸值需要有足够多的样品实测数据基础。     

旋转压缩机内润滑油分布的模拟

压缩机内润滑油分布对压缩机性能有一定影响,但由于滚动转子式压缩机的全封闭性,对观察其内的润滑油的流动状况就造成了一定的困难,因此本文利用CFD商业软件STAR-CD,采用拉格朗日法模拟滚动转子式压缩机内润滑油的分布情况。同时还计算出了高转速下旋转式变频压缩机的油循环率(OCR)的大小,压缩机的电机各个部分的油滴数量、逃逸油滴数量及质量百分比等随曲轴角度的变化情况。计算结果表明冷媒及润滑油通过定子通孔和转子气隙流到电机上部,上升不是直线上升,而是随转子转动呈螺旋式上升。在高转速下,压缩机油循环率(OCR)较高且处于波动状态。     

The impact of detergent chemistry on TBN retention

Historically, the characterisation of fresh and used diesel engine lubricants has been based on a limited number of analytical techniques. One of the most important methods of analysis has been total base number (TBN) measurement. Although TBN measurements are informative, easy, and quick, it can be misleading to base the judgement of an oil's performance solely on one criterion. This paper offers some observations from a field test, showing that some detergent types gave unacceptable performance even though the TBNs were at an acceptable level. It is hypothesised that some detergents do not effectively neutralise all acidic species present in the lubricant, thereby reserving their own base, while in fact the oil may no longer provide sufficient protection against bearing corrosion. This hypothesis is supported by bench and engine test data. It is recommended that, at a minimum, total acid number (TAN) measurements be included in any analysis, and where time and cost permit, wear metals content, oxidation, soot content, and viscosity should also be evaluated.     

船舶柴油机油质量劣化规律研究

对船舶柴油机油劣化规律进行模拟氧化试验和船舶行驶试验研究,运用红外光谱和理化指标分析所取样品的酸值、碱值、闪点、氧化值等.结果表明,模拟样品和跟踪样品随着氧化时间和航程的增加,呈黏度增加、酸值升高、碱值降低,氧化值、硝化值增大的变质趋势,且理化指标和红外指标有很好的相关性.模拟氧化试验和跟踪取样的样品的红外和理化数据变化一致,因此可以用模拟试验的数据来预测实际样品的衰变.应用模拟氧化试验可以快速研究柴油机油的劣化规律,采取红外和理化相结合的方法能够评价柴油机油的质量变化程度,实现按质换油.     

原油含水率红外光谱测量的超稀疏表示方法

油水混合物的光谱分析方法已经成为当前油水两相流测量的研究热点。然而,传统的油水混合物光谱分析中,一般是通过主成分分析、连续投影算法等降维技术实现其光谱特征提取,所提取光谱数大多在10条以上,这使得油水两相测量光纤式传感器的制造成本很高且工程实现难度很大。为提高基于光谱分析的油水两相测量光纤式传感器的实用性,需要实现油水两相红外光谱的超稀疏表示。为此提出了油水混合物光谱自-互相关联合(self-cross correlation,SCC)的光谱超稀疏表示方法。为了验证方法的有效性,搭建了油水混合物红外光谱含水率测量实验装置,从SCC算法筛选出的6个波段中,根据实际生产工艺选择了1 050 nm和1 650 nm波段进行动态实验,实验结果表明,1 050 nm和1 650 nm波段对油和水的混合流型响应良好,且两者呈现出了显著的互相关性。显然,本文研究有助于提升工业光纤式传感器的使用性能。     

基于光学传感器的成品油识别方法

为了改进现有的成品油管道油品检测方法,从油品介质的本质出发,寻找能够体现油品本质的特征来检测和识别成品油。通过分析光的变化磁场的电磁感应对介质的作用以及光在介质分子间能量传递过程建立的电子云导体模型,运用能量守恒原理对光在介质中的传播以及折射现象进行了研究,对不同成品油及其混油的折射率进行测量及相关计算,得到了计算成品油折射率和识别混油的方法。通过光学传感器接收探头与油品接触面的菲涅尔反射信号,分析光与介质的相互作用,从而完成对油品的识别以及对不同混油的区分, 相对误差＜0.02%。实验结果为油品的识别和开发研究提供了理论依据,在分析成品油管道运输中混油的成分、推断其混油状态、扩散过程等方面有一定应用前景。     

Diesel lubricant monitoring with new-concept shipboard test equipment

Accurate diesel lubricating oil testing, formerly relegated only to oil laboratories, can now be performed routinely aboard ship using a series of first-generation, new-concept, oil analysis meters. The modern design equipment yields reliable oil test data whose quality approaches that derived from traditional, but often difficult to perform, oil laboratory testing. This equipment contains operating concepts that were jointly codeveloped for fleet use by contractors with direct technical input from NSWCCD-SSES engineering personnel. The oil testers available are compact, affordable, streamlined, microprocessor-based devices, containing simplified hardware and menu-driven software. Further, these devices were designed with extensive onboard oil-test data storage capabilities. Engine test data obtained is stored so that it can be offloaded to a printer or a computer for operational trending, characteristics that are useful for long-term tracking of engine conditions, commensurate with condition-based machinery maintenance concepts. Design ideas employed in the equipment were aimed at making it essentially equivalent to laboratory testing, yet operator-friendly and easy to use. Evaluation of the testers was completed in about three years from initial conception until commercial products were realised. Included in the evaluaton studies were statistical data comparisons with established testing procedures, along with long-term fleet testing. The equipment includes kinematic viscosity, fuel dilution (FD), and total base number (TBN) meters. Additional work is continuing on the development of similar equipment for assessing moisture, solids contamination, wear/particle analysis, and total acid number (TAN) evaluations in other oils, so that the US fleet may increase real-time analysis and diagnostics capabilities.     

Application of the CONCAWE biodegradability test for oil products

Information on the biodegradability of an oil product (or its components) is needed for classification and labelling purposes. The extent to which a product can be broken down by microbial attack is usually determined using a ‘ready biodegradability’ test (e.g., OECD 301 Test Guidelines). However, these methods are stringent screening tests and can often underestimate the extent to which a product can be removed from the natural environment by biodegradation. CONCAWE (the European oil companies’ organisation for environment, health and safety) has recently developed a test for determining the potential (or ‘inherent') biodegradability of oil products. This is often more useful for assessing the likely impact of an oil product in the event of its release into the environment. This paper gives examples of CONCAWE test results for a number of base fluids and formulated products, and compares these results with those obtained in a ‘ready biodegradability’ test. Guidance is given on the applicability of data that has been obtained using the CONCAWE method.     

豆油脂肪酸修饰二氧化钛纳米微粒的摩擦学性能研究

采用表面修饰化学法制备了豆油脂肪酸修饰的二氧化钛纳米微粒,对所制备的纳米微粒通过红外光谱进行了结构表征。将二氧化钛纳米微粒作为润滑油添加剂,加入液体石蜡中,利用四球试验机考察其摩擦学性能。试验结果表明,有机基团修饰的二氧化钛纳米微粒具有优良的分散性,可提高液体石蜡的抗磨性和承载能力;加有表面修饰的二氧化钛纳米微粒的液体石蜡磨斑直径减少了39%,承载能力能够提高1倍以上。