Effect of antioxidants on the oxidative stability and combustion characteristics of biodiesel fuels in an indirect-injection (IDI) diesel engine

Biodiesel fuels that consist of saturated and unsaturated long-chain fatty acid alkyl esters are an alternative diesel fuel produced from vegetable oils or animal fats. However, autoxidation of biodiesel fuels during storage is easily caused by air, reducing fuel quality by adversely affecting its properties such as kinematic viscosity and acid value. One approach to improve the resistance of biodiesel fuels to autoxidation is to mix them with antioxidants. This study investigated the effectiveness of five such antioxidants in mixtures with biodiesel fuels produced by three biodiesel manufacturers: butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), tert-butylhydroquinone (TBHQ), propyl gallate (PrG) and α-tocopherol. An engine test was also performed to investigate the combustion characteristics of biodiesel fuel with antioxidants in an indirect-injection (IDI) diesel engine. Oxidation stability was determined using Rancimat equipment. The results showed that TBHQ, BHA, and BHT were the most effective and α-tocopherol was the least effective in increasing the oxidation stability of biodiesel. The combustion characteristics and exhaust emissions in diesel engine were not influenced by the addition of antioxidants in biodiesel fuel. This study recommends TBHQ and PrG to be used for safeguarding biodiesel fuel from the effects of autoxidation during storage.     

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.     

The effect of biodiesel and ultra low sulfur diesel fuels on emissions in 11,000 CC heavy-duty diesel engine

It seems very difficult to comply with upcoming stringent emission standards in vehicles To develop low emission engines, better quality of automotive fuels must be achieved Since sulfur contents in diesel fuels are transformed to sulfate—laden particulate matters as a catalyst is applied, it is necessary to provide low sulfur fuels before any Pt-based oxidation catalysts are applied In general, flash point, distillation 90% and cetane index are improved but viscosity can be worse in the process of desulfunzation of diesel fuel Excessive reduction of sulfur may cause to degrade viscosity of fuels and engine performance in fuel injection systems This research focused on the performance of an 11,000 cc diesel engine and emission characteristics by the introduction of ULSD, bio-diesel and a diesel oxidation catalyst, where the bio—diesel was used to improve viscosity of fuels in fuel injection systems as fuel additives or alternative fuels     

车用柴油机瞬态工况的排气颗粒数量

以一台轻型车用柴油机为样机,研究发动机定转速增转矩瞬态工况下的颗粒数量排放。所用燃料为纯柴油、纯生物柴油、B20和B50燃油。结果表明:瞬态工况期间,该机燃用柴油的核态颗粒数上升,且先缓后急;聚集态颗粒数由于瞬态工况初期进气滞后,呈先增后降的特点。总颗粒数整体上升,瞬态过程初期聚集态颗粒数起主要作用,而中后期核态颗粒数占主导地位。B20燃油的颗粒数动态变化特性与柴油类似;B50燃油和纯生物柴油的颗粒数动态特性与柴油差异较大,其中总颗粒数和核态颗粒数始终明显高于柴油,聚集态颗粒一直低于柴油,表明此时核态颗粒数在总颗粒数中的支配地位。纯生物柴油在该瞬态工况初期聚集态颗粒数就持续下降,而核态颗粒数快速上升并持续到工况过渡结束。     

Combustion characteristics of an agricultural diesel engine using biodiesel fuel

Biodiesel has great potential as an alternative fuel for diesel engines that would reduce air pollution. It is a domestically produced, renewable fuel that can be manufactured from fresh or used vegetable oils, or from animal fats. In this study, a biodiesel fuel derived from rice bran oil was tested as an alternative fuel for agricultural diesel engines. The emissions were characterized for both neat and blended biodiesel fuels, and for conventional diesel fuel. Since this biodiesel fuel contained 11% oxygen, it strongly influenced the combustion process. The use of biodiesel fuel resulted in lower carbon monoxide, carbon dioxide, and smoke emissions, without any increase in nitrous oxide emissions. The study demonstrated that biodiesel fuel could be effectively used as a renewable and environmentally innocuous fuel for agricultural diesel engines.     

Effect of Reciprocation Frequency on Friction and Wear of Vibrating Contacts Lubricated with Soybean-Based B100 Biodiesel

The use of renewable, bio-based fuels has become increasingly widespread in recent years, with a major example being biodiesel, a bio-derived alternative to Number 2 diesel fuel. The increased usage of biodiesel gives rise to an augmented need to understand its tribological effects on critical engine components. This study focused on determining the tribological performance of soybean-based B100 (i.e., pure) biodiesel within a fuel injector with varying oscillating frequency by performing a series of linear reciprocating tribological tests of biodiesel-lubricated interfaces with varying reciprocating frequency. Comparison of friction coefficient variation with reciprocating frequency indicated a transition from boundary lubrication to hydrodynamic lubrication as the frequency increased, while hysteresis loop and energy loss observations showed a transition between full stick and partial slip contact with increasing frequency. However, observations of induced wear showed the wear to increase with increasing frequency, most likely due to the augmented number of sliding cycles as well as an increased degree of interfacial slip.     

D80二甲醚-柴油混合燃料在柴油机上的应用研究

主要介绍了二甲醚-柴油混合燃料在传统柱塞式供油系统上实用化的可行性。通过混合燃料在ZS195发动机上的性能排放实验研究,确定出最优混合比例,通过模拟试验装置N-D80、纯二甲醚和柴油进行了早期柱塞磨损试验对比,并提出了采用强制润滑方式对磨损和泄漏加以改善,为其在应用化研究过程中提供实验依据。     

A study on the usability of biodiesel fuel derived from rice bran oil as an alternative fuel for IDI diesel engine

The world is faced with a problem of air pollution due to the exhaust emissions from automobile. Recently, lots of researchers have been attracted to develope various alternative fuels and to use renewable fuels as a solution of these problems. There are many alternative fuels studied in place of diesel fuel made from petroleum. Biodiesel fuel (BDF) is a domestically produced, renewable fuel that can be manufactured from vegetable oils, used vegetable oils, or animal fats. In this study, the usability of BDF, one of the oxygenated fuels as an alternative fuel for diesel engines was investigated in an IDI diesel engine. Emissions were characterized with a neat BDF and with a blend of BDF and conventional diesel fuel. Since the BDF includes oxygen of about 11%, it could influence the combustion process strongly. Therefore, the use of BDF resulted in lower emissions of carbon monoxide and smoke emissions with some increase in emissions of oxides of nitrogen. It is concluded that BDF can be utilized effectively as a renewable fuel for IDI diesel engines.     

影响柴油润滑性检测结果的因素

利用作者多年来从事柴油润滑性检测工作的经验积累,对影响柴油润滑性检测结果的诸多因素进行探讨,介绍柴油抗磨剂以及生物柴油的检测情况,这对即将在全国范围开展的柴油润滑性检测工作具有一定的指导意义.     

二甲醚(DME)汽车应用分析

这里主要介绍了作为柴油替代燃料二甲醚(DME)应用情况,并从排放、动力性、车内噪声三方面对柴油车和DME汽车进行了性能对比试验并分析了原因。     

发动机燃用生物柴油的颗粒可溶有机组分及多环芳烃排放

以一台车用柴油机为样机,研究发动机燃用生物柴油的常规排放,重点探讨其颗粒(Particulate matter,PM)、可溶有机组分(Soluble organic fraction,SOF)及多环芳烃(Polycyclic aromatic hydrocarbons,PAHs)的排放特性。所用燃油分别为柴油、生物柴油掺混配比为10%的B10燃油。结果表明,与柴油相比,该车用柴油机燃用B10燃油后颗粒、SOF和PAHs的质量排放均有所降低;NOx排放略有增加,HC和CO排放有所下降。B10燃油燃烧的颗粒SOF中醇类、酮类、醚类质量分数下降;脂类、酸类、醛类质量分数上升。在检测到的12种PAHs中,B10燃油有10种质量排放减少,尤其是苯并(a)芘等高环数致癌性的PAHs降幅明显,这表明发动机燃用生物柴油后,排气颗粒的化学成分毒性有所降低。     

Investigation of the effects of steam injection on the emissions and performance of a diesel engine using waste chicken oil methyl ester

The use of biodiesel-blended fuels in diesel engines improves the engine performance parameters and the partial recovery of incomplete combustion products, while also increasing the level of NOx emissions. In this study; biodiesel obtained through the transesterification of waste chicken frying oil was mixed with diesel fuel (90% diesel + 10% biodiesel-B10), and was then used as fuel in a direct injection diesel engine. To reduce the increased NOx emissions caused by the use of B10 fuel, the steam injection method (which is one of the NOx reduction methods) was applied. Steam was injected into the intake manifold at different ratios (5%-S5, 10%-S10 and 15%-S15) and at the time of the induction stroke with the aid of an electronically controlled system. Based on the study results, it was observed that steam injection into the engine using B10 fuel improved both the engine performance and the exhaust emission parameters. It was determined that the S15 steam injection ratio resulted in the best engine performance and emissions parameters. In comparison to STD fuel; the highest increase observed at the S15 steam injection ratio in the effective engine power was 2.2%, while the highest decrease in the specific fuel consumption was 3.4%, the highest increase in the effective efficiency was 3.5%, and the highest decrease in NOx emissions was 13.7%.

     

AutoCAD二次开发实用机械设计系统的探讨

二甲醚(DME)是一种重要的超清洁能源产品,文中分析了二甲醚的理化特性,并在D1110柴油机上掺烧D90(二甲醚柴油质量分数比9:1),结果表明:功率和转矩略低于原柴油机,PM排放大幅度下降,NOx在整个负荷范围内得到控制.结果体现了柴油机燃用二甲醚柴油混合燃料在降低排放方面的优越性能.     

Pretreatment methods to improve the kinematic viscosity of biodiesel for use in power tiller engines

Biodiesel is an environmentally friendly fuel that can replace diesel in compression ignition engines without changing the engine structure. Biodiesel is typically manufactured from vegetable oils and animal fats, which give the fuel its oxidation stability and cold-flow properties, respectively. However, the kinematic viscosity of biodiesel can cause engine performance problems such as incomplete combustion and sludge formation due to insufficient fuel atomization. To address these problems, in this study, a pretreatment technology that lowers the kinematic viscosity of biodiesel made from blended animal fat and vegetable oil was developed. The results of application of the pretreated fuel to a single-cylinder power tiller engine indicated that it produced 88.3–99.8 % of the brake power produced by conventional diesel. In addition, although the pretreated biodiesel exhaust included increased amounts of nitrogen oxides and carbon dioxide emissions, the proposed fuel also decreased the amounts of hydrocarbon and carbon monoxide emissions compared with conventional diesel emissions.

     

Performance and combustion characteristics of a diesel engine with titanium oxide coated piston using Pongamia methyl ester

Owing to the increasing cost of petroleum products, fast depletion of fossil fuel, environmental consideration and stringent emission norms, it is necessary to search for alternative fuels for diesel engines. The alternative fuel can be produced from materials available within the country. Though the vegetable oils can be fuelled for diesel engines, their high viscosities and low volatilities have led to the investigation of its various derivatives such as monoesters, known as bio diesel. It is derived from triglycerides (vegetable oil and animal fates) by transesterification process. It is biodegradable and renewable in nature. Biodiesel can be used more efficiently in semi adiabatic engines (Semi LHR), in which the temperature of the combustion chamber is increased by thermal barrier coating on the piston crown. In this study, the piston crown was coated with ceramic material (TiO₂) of about 0.5 mm, by plasma spray method. In this present work, the experiments were carried out with of Pongamia oil methyl (PME) ester and diesel blends (B20 & B100) in a four stroke direct injection diesel engine with and without coated piston at different load conditions. The results revealed 100% bio diesel, an improvement in brake thermal efficiency (BTE) and the brake specific fuel consumption decreased by about 10 % at full load. The exhaust emissions like carbon monoxide (CO) and hydrocarbon (HC) were decreased and the nitrogen oxide (NO) emission increased by 15% with coated engine compared with the uncoated engine with diesel fuel. The peak pressure and heat release rate were increased for the coated engine compared with the standard engine.     

Biodiesel production process optimization from Spirulina maxima microalgae and performance investigation in a diesel engine

Biodiesel is a renewable, easily biodegradable, eco-friendly and sustainable alternative energy source. In this investigation, crude oil was extracted from Spirulina maxima microalgae through biochemical conversion method with the help of soxhlet apparatus. Biodiesel production process parameters were optimized through base transesterification. Maximum biodiesel yield achieved was 87.75 % at optimal reaction condition after transesterification, when methanol to oil ratio was 6:1, catalyst loading was 1 % KOH (wt.%), temperature was 65 °C, and stirring speed was 600 rpm for a reaction time of 70 minutes. All the physicochemical properties of the produced biodiesel were determined and compared with the ASTM D6751 specification. Finally, performance and emission of an unmodified diesel engine was evaluated with 20 % and 40 % (v/v) biodiesel blends and compared the results with ordinary Diesel fuel (DF). Using biodiesel blends improves Hydrocarbon (HC) emission by 10-15 % and Carbon monoxide (CO) emission by 9.3-13.9 %. However, Brake specific fuel consumption (BSFC), Oxides of nitrogen (NOX), Carbon dioxide (CO₂) and smoke opacity were found to be slightly higher for biodiesel blends, and Brake thermal efficiency (BTE) was found slightly lower than DF. Thus, Spirulina maxima serves as a potential feedstock for biodiesel production and prospective fuel in diesel engine application.

     

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.     

Investigation of combustion and emission characteristics of n-hexane and n-hexadecane additives in diesel fuel

One of the most important basic requirements of diesel-powered vehicles that they have lower pollutant emissions and fuel consumption. In diesel engines, combustion and engine performance are influenced by the physical and chemical properties of the used fuel. Engine design studies are not enough to increase engine performance and reduce exhaust emissions alone. By adding fuel additives in diesel fuel, the physical and chemical properties of the fuel can be improved. Fuel additives affect engine performance, combustion and emissions positively by exerting catalyst effect during combustion. In this study, n-hexane and n-hexadecane were added in diesel fuel (D0) by volume of 4, 12 % and 20 %. With respect to D0 fuel, in DHD20 and DHX20 fuels engine torque increased by 1.60 % and 1.32 %, respectively, while the brake specific fuel consumption decreased by 3.12 % and 1.98 %, respectively. Maximum cylinder pressures and heat release rate values of the ingredient added fuels increased. It was seen that NO_x emissions increased while HC, CO and soot emissions decreased with increasing contribution ratio.

     

纯二甲醚内燃机专用喷射器防磨损性能研究

传统柴油机喷射器因二甲醚(DME)黏度太低会造成快速磨损,因而不能用于纯二甲醚内燃机中.介绍一种新型专用防磨损喷射器,利用旁通孔引流使二甲醚燃料不流过锥头杆阀的导向柱面,以避免锥头杆阀偶件受DME冲刷而引起磨损.利用Fluent软件对新型喷射器进行流量仿真,计算出旁通孔与锥头杆阀偶件环状间隙中DME的流量分布.计算结果验证了新型喷射器抵抗磨损的能力并得到一个防磨损的关键指标.     

A new engine oil optimised for ecologically sensitive operational areas

In recent years, environmental awareness and legislation have focused public attention on vehicle emissions. Consequently, more research has been devoted to emissions and pollution by lubricants. A number of studies has been carried out to understand lubricant-related emissions and leak rates as well as the effects on fuel economy of using low viscosity grades of lubricant. The purpose of the present investigation was to develop for use in gasoline and diesel engines a crankcase lubricant which contained improved performance in engine cleanliness with fuel economy and a low rate of particle emissions. Emphasis was placed on low toxicology and rapid biodegradability because of the risk of unintentional emissions. Such a sophisticated lubricant is desirable not only for normal road vehicles but also and especially for use in ecologically sensitive areas. During the development of this lubricant, numerous laboratory tests were performed. In order to assess the quality and the fuel economy of the new lubricant, tests were carried out on an engine test rig and on a vehicle test bench. Field tests were run with various vehicles and stationary engines, using different fuel types. Unleaded gasoline, diesel fuels with a varying sulphur content, and rape seed oil methyl ester (RME) were used. This paper summarises the results of this investigation.