生物降解性聚合物及其在发动机油料中的应用前景

本文综术字生物降解机理和生物降解聚合物的结构特征,以及生物降解二冲程油的概况,阐述了生物降解聚合物在发动机油料方面的应用前景。     

生物降解性聚合物及其在发动机油料中的应用前景

本文综述了生物降解机理和生物降解聚合物的结构特征,以及生物降解二冲程油的概况,阐述了生物降解聚合物在发动机油料方面的应用前景     

TC-WⅡ优质水冷二冲程油评定装置与评定方法的研究

ＴＣ－ＷⅡ级优质冷水二冲程油是当前国际上舷外机普遍采用的水冷二冲程动力装置的专用油品，也是我国正在研制和广泛推广的水冷二冲程专用油品。本文就ＴＣ－ＷⅡ水冷二冲程油评定装置和评定方法的建立与研究，做了较详细的论述。     

TC—WⅡ优质水冷二冲程油评定装置与评定方法的研究

ＴＣ－ＷⅡ级优质冷水二冲程油是当前国际上舷外机普遍采用的水冷二冲程动力装置的专用油品，也是我国正在研制和广泛推广的水冷二冲程专用油品。本文就ＴＣ－ＷⅡ水冷二冲程油评定装置和评定方法的建立与研究，做了较详细的论述。     

超级风冷二冲程油润滑性试验研究

超级风冷二冲程油的润滑性是最重要的油品特性之一。通过对润滑性的试验条件、试验程序及试验数据的计算机采集与处理等方面的研究，对超级风冷二冲程油润滑性的测试、计算方法和试验装备等的论述；对润滑性试验结果的重复性、区分性的验证，证明了研究结果是可靠的和有效的。     

二冲程油对催化反应器毒性作用的研究

通过二种不同组分的二冲程油对催化反应器的老化试验，发现二冲程油的灰分含量、清净性及某些金属成分将会加速催化反应器的老化。     

二冲程发动机控制的新方法

点燃式发动机的不足之处是小负荷时热效率低,经过100多年的发展,至今仍是利用混合气节流弥补这一不足。本文介绍的是几种新的控制方法。     

FAI二冲程缸内直喷发动机燃烧室的试验研究

试验比较了两种适合FAI二冲程缸内直喷发动机的燃烧室——半球形和斜锥形燃烧室。研究结果表明,在低速低负荷工况下,斜锥形燃烧室较为适合,HC排放和燃油消耗改善较好。     

基于大涡模拟方法的二冲程发动机缸内冷态流场的模拟研究

应用大涡模拟方法对一台二冲程发动机缸内冷态湍流流场进行了三维瞬态数值分析。探索缸内流场的速度、压力及温度的变动情况,并与PIV流场测试结果进行了对比。三维模拟的缸压曲线与试验及一维模拟均吻合较好,但在速度概率密度函数方面与试验存在一定差异。模拟结果表明:本文建立的三维模型能够自然再现缸内冷态流动的随机大尺度涡流情况,模型可靠有效。模拟能够较好地反应火花塞位置附近速度随机波动情况,其结果对于后续研究缸内大尺度涡流对燃烧循环变动的影响机理具有一定的指导意义。     

二冲程油对催化应器毒性作用的研究

通过二种不同组分的二冲程油对催化反应器的老化试验，发现二冲程油的灰分含量、清净性及结金属成分将会加速催化反庆器的老化。     

以生物质热解油为燃料的可降解发动机油的研制

针对发动机以生物质热解油为燃料的工况,通过对基础油与添加剂进行筛选评价,选用了具有良好可生物降解性的癸二酸二辛酯(蓖麻基)与油溶性聚醚复合使用作为基础油。同时根据全配方试验结果,采用模糊综合评价法对全配方进行了评价,研制出一种以生物质热解油为燃料的发动机用油。经理化性能分析可知,研制的发动机油具有良好的清净分散性、热氧化安定性、防锈性和耐磨损性等优点,可很好地满足以生物质热解油为燃料的发动机的使用要求。     

Studies on the use of orange peel oil and ethanol in an unmodified agricultural diesel engine

The aim of the present study is to investigate the suitability of Orange peel oil and ethanol blends as an alternative fuel for CI engine. Various blends of ethanol with Orange peel oil were prepared on volumetric basis and named as E5OPO95 (5% ethanol and 95% Orange peel oil), E10OPO90 (10% ethanol and 90% Orange peel oil), E15OPO85 (15% ethanol and 85% Orange peel oil) and E20OPO80 (20% ethanol and 80% Orange peel oil). All blends were found to be homogeneous and various physicochemical properties are evaluated in accordance with relevant standards. In the subsequent phase of this investigation, exhaustive engine trials were carried out on a single cylinder medium capacity diesel engine using the different test fuel samples. The result shows a marginal reduction in the brake thermal efficiency for all blends as compared to diesel. At the same time, NOx decreased slightly for all blends. The HC emissions were found to increase while CO₂ emissions decrease for different ethanol Orange peel oil blends as ethanol content increased. Moreover, the smoke opacity and exhaust gas temperature were found lower than neat diesel for all the blends.     

Performance of direct-injection off-road diesel engine on rapeseed oil

This article presents the comparative bench testing results of a naturally aspirated, four stroke, four cylinder, water cooled, direct injection Diesel engine operating on Diesel fuel and cold pressed rapeseed oil. The purpose of this research is to study rapeseed oil flow through the fuelling system, the effect of oil as renewable fuel on a high speed Diesel engine performance efficiency and injector coking under various loading conditions.Test results show that when fuelling a fully loaded engine with rapeseed oil, the brake specific fuel consumption at the maximum torque and rated power is correspondingly higher by 12.2 and 12.8% than that for Diesel fuel. However, the brake thermal efficiency of both fuels does not differ greatly and its maximum values remain equal to 0.37–0.38 for Diesel fuel and 0.38–0.39 for rapeseed oil. The smoke opacity at a fully opened throttle for rapeseed oil is lower by about 27–35%, however, at the easy loads its characteristics can be affected by white coloured vapours.Oil heating to the temperature of 60 °C diminishes its viscosity to 19.5 mm² s⁻¹ ensuring a smooth oil flow through the fuel filter and reducing the brake specific energy consumption at light loads by 11.7–7.4%. Further heating to the temperature of 90 °C offers no advantages in terms of performance. Special tests conducted with modified fuel injection pump revealed that coking of the injector nozzles depends on the engine performance mode. The first and second injector nozzles that operated on pure oil were more coated by carbonaceous deposits than control injector nozzles that operated simultaneously on Diesel fuel.     

Study on cottonseed oil as a partial substitute for diesel oil in fuel for single-cylinder diesel engine

The experiments were undertaken to obtain the knowledge necessary for raising the thermal efficiency of mixed oil composed of cottonseed oil and conventional diesel oil and for improving the performance of engine fuelled by the mixture. The experimental results obtained showed that a mixing ratio of 30% cottonseed oil and 70% diesel oil was practically optimal in ensuring relatively high thermal efficiency of engine, as well as homogeneity and stability of the oil mixture. A quadratic regressive orthogonal design test method was adopted in the experiment designed to examine the relationship between specific fuel consumption and four adjustable working parameters (intake-valve-closing angle (α), exhaust-valve-opening angle (β), fuel-delivery angle (θ) and injection pressure (P, in 10⁴ Pa)) when the above-mentioned oil mixture was used. The mathematical equations characterizing the relationship were formulated. The equation of specific fuel consumption derived from the regressive test under each operating condition was set as the objective function and the ranges for the four adjustable working parameters were the given constraint condition. Models of non-linear programming were then constructed. Computer-aided optimization of the working parameters for 30:70 cottonseed oil/diesel oil mixed fuel was achieved. It was concluded that the predominant factor affecting the specific fuel consumption was fuel-delivery angle θ, the approximate optimal value of which, in this specific case, was 3–5° in advance of that for engine fuelled by pure diesel oil. The experimental results also provided useful reference material for selection of the most preferable combination of working parameters.     

Development of engine oil using palm oil as a base stock for four-stroke engines

The use of palm oil as a base stock for an environmentally friendly lubricant for small four-stroke motorcycle engines is investigated. Palm oil was blended with mineral oil at different compositions to the viscosity requirement of commercial lubricant. A liquid additive package was added to improve the viscosity of the lubricant. A blend that meets the viscosity requirement was then chosen for physical and chemical property characterization and subjected to an engine test. The blend consists of 50.6% (wt.) palm oil, 41.6% mineral oil, and 7.8% additive package. The properties evaluated include viscosity, viscosity index, flash point, foaming characteristics, and wear scar. The engine performance and emission tests were carried out with a 125-cc motorcycle on a chassis dynamometer using a Bangkok Driving Cycle. Compared to a mineral-based commercial oil, the palm oil-based lubricant exhibits superior tribological properties, but offers no clear advantage on engine and emission performance.     

Molecular dynamics simulation on engine oil nanolubricant boundary lubrication conditions

The employment of nanoparticle additives in engine oil provides an effective technique for improvement in engine performance and emission. In this study, graphene, graphene–MWCNT, and graphene–SiO₂ hybrid nanoparticles have been dispersed in engine oil (n-decane) to measure the effects of microscopic characteristics of interfacial layer between the carbon–carbon, carbon–hydrogen, carbon–oxygen, and hydrogen–oxygen molecules under fixed shear rate 600 s⁻¹. The boundary lubrication conditions are depicted with nanoindentation operation, in which interaction between the atoms generates the molecular forces under indentation and scratching operation that provide the nucleation and propagation of dislocation in the planes. The result shows that in an early stage of nanoindentation, plastic deformation occurs in the lubricant substrate around the indenter. Furthermore, forces generated in the z-direction have a significant effect as compared with the forces x- and y-directions. Nanoindentation results concluded that for graphene–MWCNT/engine oil (n-decane) nanoparticles, at a volume fraction of 1.8%, the nanoparticles outperformed all other nanolubricants. At a volume fraction of 0.3%, the adhesion between the solid and liquid interface was increased by 2.5% graphene nanolubricant, 4% graphene–MWCNT nanolubricant, and 8% graphene–SiO₂ nanolubricant. At 1.8% volume fraction, 240% increase in graphene–MWCNT nanolubricant, 72% increase in graphene nanolubricant, and 20% increase in graphene–SiO₂ nanolubricant. This trend indicates that the performance of graphene SiO₂ nanolubricants is superior at low-volume fractions, whereas the performance of graphene nanolubricants and graphene–MWCNT nanolubricants is superior at high-volume fractions. Also we observed the scratching effect of indenter on nanolubricants.     

Performance and emission analysis of compression ignition engine using biodiesels from Acid oil,Mahua oil,and Castor oil

Research on and use of biodiesels for engines is growing continuously in the present era. Compression ignition (CI) engine performance for biodiesels of blends B20 from Acid oil, Mahua oil, and Castor oil is experimentally investigated. The engine performance analysis in the form of brake‐specific fuel consumption, brake‐specific energy consumption, brake thermal efficiency (BTE), exhaust gas temperature (EGT), and air fuel ratio are compared with diesel as base fuel. Emission characteristics like CO, CO₂, NOx, and opacity are comparatively studied in detail for the considered biodiesels. The entire study is compared with the performance of engine when pure diesel is chosen as fuel. From the complete analysis it was observed that the BTE was higher for Acid oil and Mahua oil among the biodiesels used. And regarding CO emissions, Mahua oil showed lower effect than other biodiesels. Upto 6% increase in EGT of Mahua oil was obtained at no load and for other loads the percent reduced. For all the biodiesels the % enhancement in Co, CO₂, and NOx was more than 60% at highest load compared with diesel.     

Study on noise of rapeseed oil blends in a single-cylinder diesel engine

This study was undertaken to obtain the knowledge necessary for reducing noise of mixed oil composed of rapeseed oil and conventional diesel oil and for improving the performance of engine fuelled by the mixture. A S195 (8.8 kW) type single-cylinder diesel engine was used to determine the effect of four adjustable working parameters, i.e. intake-valve-closing angle (α), exhaust-valve-opening angle (β), fuel delivery angle (θ) and injection pressure (P, in 10⁴ Pa) on noise when an oil mixture of 30% rapeseed oil and 70% diesel oil was used. Single-factor and multi-factor quadratic regressive orthogonal design test method were adopted in the experiments to find the relationship between noise and four adjustable working parameters. Relationship between these parameters and noise was analysed under two typical operating conditions and mathematical equations characterizing the relationship were formulated. The equation of noise from the regressive test under each operating condition was set as the objective function and the ranges for the four adjustable working parameters were the given constraint condition. Models of nonlinear programming were then constructed. Computer-aided optimization of the working parameters for 30:70 rapeseed oil/diesel oil mixed fuel was achieved. Field test verified that the engine (in use) working condition was found to be bad at maladjustment. The optimum working parameters for two working conditions of the engine were used to adjust the four working parameters. Test results showed that optimum adjustment could achieve noise reduction between 2 and 4 dB and that the power could be increased by 0.6–1.8 kW. The experimental results also provided useful reference material for selection of the most preferable combination of working parameters.     

Production of diesel-like fuel from waste engine oil by pyrolitic distillation

The aim of this study is to obtain diesel-like fuel from waste lubrication engine oils by pyrolitic distillation method, which can be used in diesel engines. With this aim in mind, waste engine oil is collected in a tank, and it is purified from contaminants such as dust, heavy carbon soot, metal particles, gum-type materials and other impurities by filtering in the process prepared earlier. To investigate effects of additives known as sodium carbonate (NaCO₃), zeolite and lime (CaO) on density, viscosity, flash point, sulfur content, heating value and distillation temperature, the purified oil samples are blended separately with additives having mass basis of 2%, 4%, 6%, 8% and 10%. The mixed samples are exposed to pyrolitic distillation process to produce fuels to be used in engines. Thermal and physical properties of the produced fuels such as density, flash point, viscosity, sulfur content, heating value and distillation temperatures are examined. From these results, the CaO with a ratio of 2% has the highest effect on decreasing of sulfur content of the waste engine oil and on acquiring the most suitable distillation temperatures close to values of a diesel fuel. Diesel-like fuel (DLF) is obtained as 60% of the waste lubrication engine oil.     

铁路内燃机车柴油机油烟炱含量的测量

介绍了近年来柴油机的发展及评定项目、几种烟炱的测定方法以及铁路柴油机油烟炱含量的测试。