石油产品总酸值测定的新方法--伏安法

介绍了用伏安法测定石油产品总酸值的原理、方法,并将伏安法测定润滑油酸值的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石油产品总酸值是可行的,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滴定终点,因此,该方法能够实现全自动分析。     

基于电化学分析的润滑油酸值和碱值测定

研究了基于电化学分析的润滑油酸值/碱值测定技术。基本原理是应用信号转换技术和特定化学反应将电化学分析不可测的润滑油酸值/碱值信息转换为电化学分析可测量,实现酸值/碱值的电化学分析。实验结果表明题示方法的测定结果与国家标准方法测定值有很好的一致性,是一种值得推广的快速测定技术。     

傅立叶变换红外光谱快速测定润滑油碱值

提出了利用傅立叶变换红外光谱快速测定润滑油碱值的方法,介绍了其原理及分析过程.该方法与国家标准方法相比,具有速度快、环保且化学试剂用量小、精密度高,操作方便等特点,适用于常规、快速分析.研究结果表明所建方法与国家标准方法的测定结果之间具有很好的一致性,测定结果的相对标准偏差小于5%.     

发动机油的碱值保持能力与抗氧化性能关系

为探讨发动机油的碱值保持与抗氧化性能的关系,通过模拟试验和行车试验考察使用过程中发动机油的酸值、碱值的变化,分析发动机油抗氧化性能与碱值保持的关系,并从碱值分析技术缺陷入手初步探讨如何看待和分析发动机油碱值的变化。结果表明:油品氧化过程中碱值降低与酸值增加量之间无明确的对应关系,单纯使用碱值进行发动机油的性能监测和判断油品的抗氧化性能好坏并不科学;由于影响发动机油性能的因素较多,用行车试验来研究碱值的变化与抗氧化性能关系,很难得出理想的结果。     

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     

综合评判法在内燃机油状态监测中的应用

研究了综合评判法在内燃机油状态监测中的应用,确定内燃机油的综合评判指标,建立内燃机油的综合评判标准,并基于内燃机油的现场检测结果,绘制能反映内燃机油状态变化趋势的劣化倾向曲线。结果表明：该综合评判法对监测内燃机油的状态是十分实用和有效的,并对机械设备的润滑管理工作具有一定的指导意义。     

内燃机快速升温挡油板的开发

本文主要是介绍一款新的内燃机快速升温挡油板的开发,相比目前市场上正在使用的内燃机挡油板,此快速升温挡油板具有内燃机冷启动时实现机油的快速升温,进而降低内燃机各个运动副的摩擦损失,降低整机的燃油消耗,通过整车NEDC或者WLTP循环测试,可以降低CO2排放2%左右。     

ICP-AES法测定复混肥料中钾含量的研究

复混肥料中的钾用ICP-AES法测定结果与用国家标准方法测定结果完全吻合。用该法测定复混肥料中钾的含量,是一种简便快速的好方法。     

润滑油抗氧剂含量的循环伏安法测定

对润滑油中抗氧剂的循环伏安测定方法做了详细的研究。这种方法可以快速对润滑油中抗氧剂进行测定 ,测定结果与传统技术测定结果具有一致性     

内燃机机械效率的快速测定

内燃机机械效率的测定方法很多,不过有些方法需要较复杂的设备和仪器,所以快速简便的测定法在当前仍有重要意义。 目前多数工厂采用单缸熄火法和油耗法测定内燃机机械效率。后者需要测定和绘制内燃机标定转速时的负荷特性,绘制功率—燃料小时消耗量曲线,并作图确定该转速时的摩擦功率,进而算出机械效率。我们在此基础上作了简化,式中η_m—机械效率;G_(ro);—标定转速空负荷时每小时燃料消耗量(公斤/小时);G_th;—标定转速、标定功率时每小时燃料消耗量(公斤/小时)。     

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.     

The effect of water on the acid-base properties of new and used IC engine lubricating oils

The absolute values of total base number (TBN) were determined for several sets of both fresh and used engine oil samples. Basic and acidic compounds from these oils have been extracted into water, 7% sea water and ethanol-water (1:1, v/v) mixtures. The extracts have been determined by potentiometric titration as pH extracts, TBN (water extract) and alkalinity. The oil formulations are not resistant to the presence of water but basic additives in fresh oil are more resistant than those for used oils. The percentage of TBN extractable into water significantly increases with service life. The presence of significant amounts of water in lubricating oil is serious and should form part of any lubricant condition monitoring system. The case is argued for both the use of dehydration canisters in oil systems and for the development of a new method of water content determination for used formulated lubricating oils which is quick, accurate and suitable for automated condition monitoring systems. The pH of aqueous extracts for condition monitoring of lubricating oils is shown to be only meaningful for TBN values of 2 or less.     

Modelling of lubricant oil alkalinity in diesel engines

During the operation of a diesel engine, alkaline additives are gradually exhausted in neutralizing the acidic products of combustion. This is manifested by the decrease in total base number (TBN) value of engine oil during usage. The present work is an attempt to model the rate of TBN depletion in a diesel engine. Various models in vogue are discussed. A correlation between ‘system variables’ and the rate of TBN depletion is presented. Methods of multiple regression analysis are applied to the experimental data to establish the correlation. The coefficient of correlation for the proposed model is 0.9888. At 99% confidence level the chi-square test is successful, proving that the regression model is acceptable.     

Acid-base determination of lubricating oils

The base content, total base number (TBN), has been determined for a range of petroleum products and used engine oils, by both potentiometric and conductimetric methods. Titration values depend both on the method of detection and solvent media used. A conductimetric titration method for TBN is described based upon IP 177 and 276 (ASTM D-664 and 2896) solution chemistry. The results of the conductimetric titration TBN determinations are compared with those from IP 177 and IP 276 potentiometric determinations to show that the TBN order of magnitude is IP 276 (potentiometric) > conductimetric > IP 177 (potentiometric). The conductimetric method equilibrates very rapidly and is suitable for automatic titrimeters. Results for new and used oils determined by these different titration methods are discussed. Conductimetric detection for TBN determination uses standard IP method reagents and solvents and is an alternative to the trisolvent TBN method.     

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.     

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.     

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。     

高分辨质谱直接分析食用油中脂肪酸甘油酯

食用油中不饱和脂肪酸甘油酯的含量与人体健康密切相关,针对其建立快速有效的检测方法具有重要意义。本研究建立了一种可直接分析食用油中脂肪酸甘油酯的方法,采用大气压化学电离-高分辨质谱技术（APCI-HRMS）对食用油中脂肪酸甘油三酯及脂肪酸甘油二酯分子直接进样分析,在指纹区高分辨质谱数据的基础上,采用分解系数和平均不饱和度（DBE）对不同油品进行比较分析。结果表明,食用油与餐厨回收油及动物油具有明显差别,当分解系数大于10时,或DBE小于3时,可判断样品为餐厨回收油或动物油,利用这两个特征参数可成功地区分食用油与餐厨回收油样品。通过偏最小二乘法的分组验证,以及添加不同比例餐厨回收油的食用植物油样品分解系数和平均不饱和度的比较验证,表明该方法可便捷、准确地分析油品中脂肪酸甘油酯的含量变化,有望成为监测食用油品质的快速、有效的新型分析方法。     

润滑油基础油高温氧化沉积特性的研究

通过对比研究，利用加压差示扫描量热双峰法考察了加氢异构脱蜡基础油和溶剂精制基础及其不同组分的高温氧化及沉积物生成特性，并对添加剂的影响进行了研究。结果表明：异构脱蜡基础油和饱和烃的氧化安定性分别低于溶剂精制基础油和芳烃组分，但抗沉积物生成特性好于后者.添加剂对两种基础油氧化安定性有不同的影响，但会导致沉积物增多。