Performance and emission characteristics of conventional engine running on jatropha oil

A number of studies have recently been conducted to determine a suitable alternative fuel for conventional engine. The use of renewable fuels such as bio-ethanol, biogas, and biodiesel is thus investigated for this purpose. Performance tests were conducted on an indirect injection compression ignition engine by using diesel, unheated jatropha oil (JO), and preheated JO as fuels. The effects of fuel injection pressure and fuel inlet temperature on engine performance and emission for the different fuels were analyzed. Test results showed that the brake thermal efficiency of the engine with heated JO oil is superior to that with unheated JO, increasing from 28.4% with neat unheated JO to a maximum of 30.8%. The brake specific fuel consumption was reduced from 0.301 kg/kWh to 0.266 kg/kWh. Smoke opacity was also reduced relative to the neat unheated JO operation.     

Experimental analysis on neat mustard oil methyl ester subjected to ultrasonication and microwave irradiation in four stroke single cylinder Diesel engine

Transesterification of fatty acid using the application of ultrasound stirring and microwave irradiation has been used of late for biodiesel production from various vegetable oil and animal fats. However analysis on influence of these techniques on performance, combustion and emission aspects has received little attention. In this work, transesterification of mustard oil with methanol was performed using ultra sound stirring (42 kHz /170 W, 80 W) and microwave irradiation (230v AC, 50 Hz, 900 W). Reaction time, conversion rate, fuel properties, performance, emission and combustion characteristics were compared with conventional transesetrification. Results indicated that Mustard oil methyl ester subjected to ultrasonication and microwave irradiation (MOMESUM) has 5.71% more yield than conventional transesterification process. It was also observed that BTE for MOMESUM is improved by 5.84% with 5.14% reduction in BSFC when compared to MOME. CO, HC, NOx and Smoke emission was found to decrease by 11.39%, 3.81%, 7.99% and 5.3% respectively for MOMESUM.     

Synthetic two-stroke engine oil as a tool of exhaust emission control

Polypropylene oligomers were used to formulate two-stroke (2T) engine oil for once-through lubrication systems, to enhance the exhaust emission characteristics of two-stroke engines. The oligomers alone are suitable from a stability viewpoint, but must be reinforced with polyol-ester components to have good load-carrying capability. Both ash-forming and ash-free commercial additive packages can be used to formulate the end-product. The exhaust stream includes the unburnt portion of the fuel:oil mixture. The lubricating oils formulated on polypropylene oligomer base do not contain polynuclear aromatics, the sulphur-dioxide emission is due to the sulphur content of the fuel and additive (if any). On a bench test, the hydrocarbon emission was significantly lower using polypropylene oil, in comparison to using a commercial mineral-oil-based composition.     

An experimental study on the performance and emission characteristics of a CI engine fuelled with Jatropha biodiesel and its blends with diesel

The performance and emission characteristics of a compression ignition engine using mixture of jatropha biodiesel and mineral diesel have been experimentally investigated. It is observed that brake specific fuel consumption increases with higher percentage of biodiesel in the blends. Brake thermal efficiency decreases with the increased percentage of biodiesel in the blends. The maximum efficiency is found to be 29.6% with pure diesel and 21.2% with pure biodiesel. Carbon mono-oxide and hydrocarbon emissions are improved with the addition of biodiesel to diesel. NO_x emission is found to be increased with pure biodiesel by 24% compared to mineral diesel.     

Sulphur emissions from engine oil: Information from the sulphur emission index

Data published by the Institute of Materials including information on the volatility, sulphur content, and sulphur volatility of 913 engine oils were compiled. These engine oils were collected in three geographic regions: North America, Europe, and Asia. The volatility data were generated using a Selby—Noack instrument in which all volatilised material is collected for the further analysis of phosphorus and sulphur content. It was found that under the normal Noack test exposure conditions of 250°C for one hour, the sulphur emission index (a measure of sulphur volatility in mg/l) varied markedly among the engine oils. In a correlation study, a minor correlation of up to %R²= 15 was found between sulphur volatility and oil volatility while a greater correlation of up to %R² = 39 was found between sulphur volatility and sulphur content of the formulated engine oils. A new concept and application of the sulphur volatility ratio may be useful in explaining the observations concerning sulphur volatility dependence.     

某发动机转子机油泵总成噪声优化研究

为解决某发动机工作转速范围内所出现的啸叫声问题,对转子机油泵总成噪声进行优化研究。通过分析转子机油泵噪声机理,结合发动机台架试验得到的噪声频谱,分析噪声特征与来源;以降低噪声为优化目标,针对突出的声学缺陷对转子机油泵总成的结构进行优化设计。结果表明,采用优化方案后,该机油泵一阶振动速度降低,且困油区压力最大值平均降低约56%,阶次噪声明显改善,背景宽频能量有所降低,噪声的总声压级降低了2.8 dB。优化方案有效改善了该机油泵总成声学特性,为同类结构声学优化提供了思路。     

Statistical study of organomolybdenum compounds in an engine oil formulation and the results of engine testing

Organomolybdenum compounds are versatile lubricant additives of interest in the design of engine oils to meet the new ILSAC (International Lubricant Standardization and Approval Committee) GF‐3 performance standard, especially for fuel efficiency. In this work, organomolybdenum and 13 other components were studied by experimental design and statistical analysis to determine their effects on friction, wear, and oxidation properties. The resulting linear model was used to construct a trial engine oil formulation. Engine test results, including some new tests required for ILSAC GF‐3, confirmed some of the strengths of organomolybdenum compounds, as well as their sensitivity to other additives in the formulation.     

Performance and emission characteristics of a low heat rejection spark ignited engine fuelled with E20

In internal combustion engines, the concept of low heat rejection (LHR) using thermal barrier coating on the surface of combustion chamber is gaining attention. Thermal barrier coating reduces the heat transfer to the cooling system, protects engine components from peak heat flux and fluctuating temperature produced during combustion and improves the performance of the engine. Information in the literature is plentiful for LHR diesel engine and only few studies exist on LHR spark ignited engine. The application of thermal barrier coating in spark ignited engine is limited by pre-ignition and knocking due to elevated combustion chamber temperature. A spark ignited engine with moderate insulation on the combustion chamber and higher octane fuel can overcome this difficulty. The objective of the present experimental study is to quantify the changes in performance and emission characteristics brought by partial thermal insulation on the combustion chamber of a four stroke spark ignited engine fueled with E20 blend. Partial thermal insulation was created by coating 0.3 mm thick Alumina (Al₂O₃) on the cylinder head, inlet and exhaust valves. The changes are quantified with respect to unmodified engine fueled with gasoline. The combustion parameters such as flame development and rapid burn duration are also estimated and compared. The results indicate that partially insulated SI engine when fueled with E20 improves performance and reduces emission. A maximum of 48% reduction in THC and 50% reduction in CO emission at part load was achieved.

     

Gas chromatography with an atomic emission detector for turbine engine lubricant analysis

Lubricants and/or additives may need characterisation, or detection of contaminants and their identification. Analysis of turbine engine lubricants using Gas Chromatography with an Atomic Emission Detector (GC-AED) is shown to be a function of the versatility of its multi-element detection ability, and to offer advantages over previously used chromatographic detectors. GC-AED can reveal identity of elements, and this paper presents GC-AED results for MIL-L-7808 turbine-engine lubricants, and for some thermally stable hightemperature candidate organic compounds — polyphenyl ether, phenyl thioethers, and cyclotriphosphazenes.     

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.     

Analysis of engine oil and phosphorus volatility

An apparatus has been designed that allows the measurement of phosphorus volatility, which is important in, among other things, controlling the degradation of exhaust catalysers in automobiles. Following on from the original Noack volatility test, the Selby—Noack apparatus can measure up to 99.9% of volatiles. The apparatus has been used in the present work to assess the relationship between engine oil volatility and engine oil phosphorus volatility (from additives), some reflections on which are presented.     

电控汽油喷射发动机燃油压力的测量方法

介绍了对电控发动机进行性能检测与故障诊断的基础项目之一的燃油压力检测的具体方法,并通过分析检测结果对燃油系中的一些元件做出性能判断.     

基于人工神经网络的柴油机排放及EGR率预测

柴油机的EGR脉谱和柴油机排放曲线都是严重的非线性,模型过于复杂,不能直接用于控制.本文将人工神经网络应用于增压柴油机EGR控制上,建立了柴油机的BP网络模型,通过实验数据进行模拟分析,可以证明,人工神经网络辨识各参数间的关系简单易行,当学习样本足够多时,网络的预测值能够和试验值高度吻合.     

Effect of different lubricating oil on the adsorption/desorption process of fuel in oil layer in an SI engine

A diffusion equation given by Fick's law is used to study the effect of different lubricants on adsorption/desorption process of fuel in oil layer that contributes to about 25–30% of total engine‐out hydrocarbon emissions in spark ignition engine. A comparative study is carried out between the six lubricants, namely, squalane (C₃₀H₆₂), SAE0W20, SAE10W30, SAE10W40, SAE10W60 and SAE15W60. The Henry's constant and diffusion coefficient are found to be the two most important parameters that affect the amount of fuel in oil layer. The Henry's constant dominates the adsorption/desorption process at high temperatures of oil, whereas at low temperatures, diffusion coefficient effect prevails. The percentage of fuel adsorbed/desorbed into oil layer is found to be dependent on engine speed, equivalence ratio and engine load. The results are found to be in good agreement with experimental trends of hydrocarbon emissions when tested on a single cylinder SI engine using the lubricants SAE10W30 and SAE10W40. Copyright © 2016 John Wiley & Sons, Ltd.     

Performance of an Al-Si-graphite particle composite piston in a diesel engine

Al-Si-graphite particle composite alloy pistons containing different percentages of about 80 μm uncoated graphite particles were successfully cast by foundry techniques. Tests with a 5 hp single-cylinder diesel engine show that Al-Si-graphite particle composite pistons can withstand an endurance test of 500 h without any apparent deterioration and do not seize during the running-in period. The use of the Al-Si-3% graphite particle composite piston also results in (a) up to 3% reduction in the specific fuel consumption, (b) considerable reduction in the wear of all four piston rings, (c) a reduction in piston wear, (d) a 9% reduction in the frictional horsepower losses of the engine as determined by the motoring test and (e) a slight increase in the exhaust gas temperature. These reductions (a)–(d) appear to be due to increased lubrication from the graphite particles which are smeared on the bearing surface, the higher damping capacity of the composite pistons and the reduced coefficient of thermal expansion of the composite pistons. Preliminary results indicate that aluminum-graphite particle composite alloy is a promising material for automotive pistons.     

甲醇裂解气-柴油混合燃料对柴油机排放的影响

为研究甲醇裂解气-柴油混合燃料对柴油机排放的影响,设计了一种集成式尾气裂解甲醇反应器和进气共轨系统,将YC6A220型柴油机改装成燃烧由甲醇裂解而成的氢富气与柴油混合燃料的柴油机。实验研究表明,改装后的柴油机在中、高负荷运行时可以使NOx、HC和碳烟大幅度降低,且随着甲醇裂解气掺烧量的增加,各排放物质的减少量增加。     

Effects of oil properties on spark-ignition gasoline engine friction

The effects of base oil, friction modifier (FM) and viscosity grade on firing engine friction are investigated in an automotive gasoline engine. Unique aspects of the study are (1) viscosity grade is maintained when synthetic and conventional base oils are compared, (2) the influence of engine operating condition on the effectiveness of base oil, FM and viscosity grade in reducing engine friction is considered, and (3) friction-relevant design details of the test engine are discussed. Results show that replacing conventional oil with synthetic oil of the same viscosity grade reduces friction, especially at high boundary friction conditions. Molybdenum dithiocarbamate (MoDTC), and to a lesser extent organic FM, also reduce friction, especially at high boundary friction conditions. Furthermore, using 5W-20 oil causes less friction than 5W-30 and 10W-40 oil at both high and low boundary friction conditions. Results are expected to hold true for engines with similar friction-relevant designs.