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.     

Performance and emission studies on an agriculture engine on neat Jatropha oil

Diesel engines have proven their utility in the transportation, agriculture, and power sectors in India. They are also potential sources of decentralized energy generation for rural electrification. Concerns on the long-term availability of petroleum diesel and the stringent environmental norms have mandated the search for a renewable alternative to diesel fuel to address these problems. Vegetable oils have been considered good alternatives to diesel in the past couple of years. However, there are many issues related to the use of vegetable oils in diesel engine. Jatropha curcas has been promoted in India as a sustainable substitute to diesel fuel. This study aims to develop a dual fuel engine test rig for evaluating the potential suitability of Jatropha oil as diesel fuel and for determining the performance and emission characteristics of an engine with Jatropha oil. The experimental results suggest that engine performance using Jatropha oil is slightly inferior to that of diesel fuel. The thermal efficiency of the engine was lower, while the brake-specific fuel consumption was higher with Jatropha oil compared with diesel fuel. The levels of nitrogen oxides (NOx) from Jatropha oil during the entire duration of the experiment were lower than those of diesel fuel. The reduction of NOx was found to be an important characteristic of Jatropha oil as NOx emission is the most harmful gaseous emission from engines; as such, its reduction is always the goal of engine researchers and makers. During the entire experiment, carbon monoxide (CO), hydrocarbon (HC), and carbon dioxide (CO₂) emissions in the case of using Jatropha oil were higher than when diesel fuel was used. The higher density and viscosity of Jatropha oil causes lower thermal efficiency and higher brakespecific fuel consumption. The performance and emission characteristics found in this study are significant for the study of replacing diesel fuel from fossils with Jatropha oil in rural India, where the availability of diesel has always been a problem.     

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.

     

Study of performance and emission characteristics of IC engines by using diesel–water emulsion

Due to the shortage of petroleum products and its increasing cost, efforts are on to develop alternate fuels, especially diesel oil, for partial or full replacement. Also, internal combustion engines generate undesirable emissions during combustion process. The emissions exhausted in to the surroundings pollute the atmosphere and causes several problems. The emissions of concern are: unburnt hydrocarbons, oxides of carbon, and oxides of nitrogen (NO_X). Advanced diesel fuel formulations offer significant emission reductions to new and older in-use engines every time the fuel tank is filled. The addition of water to diesel fuel lowers particulate emissions by serving as diluents to the key combustion intermediates that lead to particulate formation. The incorporation of water also reduces NO_X emissions by lowering the peak combustion temperatures through high heat of vaporization. When using water blend diesel, the engine fuel system recognizes the liquid as diesel fuel because the water droplet is encapsulated within a diesel fuel. In this experiment, we have used single cylinder four-stroke engine and the water-blend diesel emulsion is used and the diesel emission test, emulsion emission test, and various gases has been analyzed; smoke meter test is also conducted for various rate of loads. The test results from the engine fuelled with water-blend diesel showed reduction in emissions as compared to that of engine fuelled with conventional diesel. The better emissions in the CI engine using water-blend diesel is due to the incorporation of water which reduces NO_X emissions by lowering the peak combustion temperatures. Water-blend fuel enhances fuel atomization by micro-explosion. The addition of water to diesel fuel lowers particulate emissions by serving as diluents to the key combustion intermediates that lead to particulate formation     

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     

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.     

Effect of lubricating oil additives on particle size distribution and total number concentration in diesel engine

This paper investigates the characteristics of particle size distribution in exhaust gas of engine fuelled with pure diesel and with diesel mixed with base oil or with oil additives. The experiments are conducted on a turbocharged diesel engine with fast particulate spectrometer DMS 500 connected to the exhaust pipe. Base oil and two kinds of commonly used lubricating oil additives, antioxidant additives and antifoaming additives, are chosen to be added into the fuel, with the concentrations being 0.5%, 1.0% and 1.5% of fuel weight individually. The particle size distribution is measured under medium load (100 Nm) and full load at different speeds. The results indicate that the existence of base oil or oil additives shows great influence on particle size distribution. Copyright © 2012 John Wiley & Sons, Ltd.     

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.     

Effects of B100 Biodiesel on Injector and Pump Piston

In this study, the effects of biodiesel use in a diesel engine on an injector and fuel injection pump piston were experimentally analyzed. To this end, two engines with the same technical specifications were used; petroleum diesel was used in one of the engines and 100% (B100) biodiesel was used in the other engine. After the engines were run for 200 h, their injectors and pump pistons were examined and compared by performing scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analysis measurements. SEM and EDX analyses showed significant structural changes on the surfaces of the injector nozzle and pump piston in the event that B100 is used.     

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.     

The characteristics of biodiesel and oxygenated additives in a compression ignition engine

In this study, experiments on the simultaneous reduction of smoke and NOx emissions of indirect-injection (IDI) diesel engines were conducted using a biodiesel fuel (BDF) and ethylene glycol mono-n-butyl ether (EGBE), which is an oxygenated fuel of mono-ethers, as a pre-processing method and by applying cooled EGR. A four-cylinder, water-cooled IDI diesel engine was used, while the engine performance and emission characteristics were considered using diesel fuel, BDF 100%, and a mixed fuel BDF and EGBE (maximum EGBE mixing ratio in mixed fuel: 20 vol-%). Results showed the BDF and the BDF and EGBE mix had significantly better smoke reduction effects than the diesel fuel. In particular, the use of the BDF and EGBE mix and the simultaneous application of 10% cooled EGR were confirmed to have reduced both smoke and NOx emissions.     

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.

     

Coefficient of Engine Flexibility as a Basis for the Assessment of Vehicle Tractive Performance

The paper attempts to analyze full load characteristics of over 500 combustion engines. Using statistical tools, the author determined the value of the coe cient of flexibility. Engine flexibility is the capability of the engine to adapt to varying loads. Importantly, in the investigations, the author took into account the parameters calculated in the course of the investigations on a chassis dynamometer, i.e., actual, not taken from technical specifications of brand new vehicles. Di erent stages of operating wear allow a better characterization of the population. Subsequent utilization of the results in tractive calculations is more reliable. The engines were divided into in six groups, depending on the type of fuel system: fuel injected gasoline and turbocharged gasoline, spark ignition LPG, naturally aspirated diesel and turbocharged diesel. However, engines running on alternative fuels are characterized with a greater flexibility than the fuel injected base engines. Conformity of flexibility of fuel injected and LPG IV generation engines have been observed,which confirms the appropriateness of engine adaptation to alternative fueling. Gasoline engine supercharging allowed a reduction of the maximum engine speed of the maximum torque, which extends the range of analyzable speeds for flexibility and consequently, the flexibility as such.     

柴油车燃油预加热系统设计方案

本设计方案主要是为了解决当车辆所行驶的外界温度低于车辆所加注的柴油能够使用的最低温度,造成柴油流动性下降从而引起的发动机供油不畅甚至熄火的问题。通过利用发动机排气余热给油管内的柴油预加热,使之能够给发动机提供满足其正常工作需要的燃油的目的。并能够适当降低柴油牌号(实现在使用-10号柴油的地区用0号代替)从而进一步提高车辆的使用经济性。     

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.     

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.     

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%.

     

An investigation on the performance of a Brayton cycle waste heat recovery system for turbocharged diesel engines

A Brayton cycle waste heat recovery (WHR) system for turbocharged diesel engines was proposed and the performance of a diesel engine integrated with the proposed system was investigated. The waste heat recovery system is integrated with the turbocharging system of diesel engines, using the turbocharger compressor as the Brayton cycle compressor. The engine cycle simulation code GT-Suite 7.0 was used to investigate the performance of a diesel engine integrated with the WHR system. A Brayton cycle turbine was designed and its performance was simulated with a through-flow model. The turbocharging system of the original engine was modified and the energy flow distribution between the diesel cycle and the Brayton cycle was optimized. Results show that the fuel economy of the diesel engine can be improved by 2.6% at high engine speed and 4.6% at low engine speed under engine full load operating conditions when equipped with the Brayton cycle WHR system. The influence of turbocharger parameters on the WHR engine performance was invesgated.     

Demonstrating Improved Fuel Economy Using Subsystem Specific Lubricants on a Modified Diesel Engine

Fuel economy performance in modern internal combustion engines is of increasing importance to lubricant formulators due to regulations targeting global greenhouse gas emissions. Engines typically employ a single lubricant, with a common sump, to service all components. As a result, base oil and additive selection for fuel economy performance is a compromise among competing demands for different engine subsystems. Opportunities for significant fuel economy improvement through targeted formulation of lubricants for specific engine subsystems are presented, with specific emphasis on segregating the lubricant supplies for the valve train and the power cylinder subsystems. A working prototype was developed in a lab environment by modifying a commercially available twin-cylinder diesel engine. Motored valve train and whole-engine fired test results were obtained and compared to model data. Fuel economy benefits were demonstrated using market representative heavy-duty diesel lubricants, including mineral oil and polyalphaolefin (PAO) blends. The fuel economy benefits of a dual-loop lubricant system are demonstrated through significant viscosity reduction in the power cylinder subsystem, achieving overall engine friction reductions of up to 8% for the investigated operating condition. Results suggest that additional gains may be realized through targeted base oil and additive formulation. Implications for incorporation in larger diesel engines are also considered.     

A model and the methodology for determining wear particle generation rate and filter efficiency in a diesel engine using ferrography

A mathematical model was developed that describes the wear particle concentration as a function of time in a diesel engine. This model contains engine and lubrication system parameters that determine the concentration of wear particles in the engine sump. These variables are the oil system volume, oil flow rate, particle generation rate, filtering efficiency and the initial particle concentration. The model was employed to study the wear particle concentrations in the sump and the mass of particles in the filter for the Cummins VT-903 diesel engine. In addition, the model was used to develop a testing methodology for determining wear particle generation rates and filter efficiencies from used oil analysis. This testing methodology uses ferrography together with computer programs to yield accurate statistical information on the data as curve fitted to the model. The test set-up incorporated a remote-controlled sampling system that enabled the accurate and periodic taking of oil samples over an engine test approximately 5 h in duration.

Results of this research indicate that equilibrium wear particle concentrations increase with an increase in engine speed and load. The wear particle generation rate and filter efficiency as determined by the test methodology were found to decrease with an increase in engine speed and load. After oil and filter changes, the wear particle generation rate and filter efficiency continually increased with cumulative engine time up to approximately 11 h. The test methods used to obtain the results above were found to be repeatable to within ±15% and could conceivably be employed to determine wear parameters on other diesel engines as well as the effects that other engine variables such as lubricants, oil temperature, coolant temperature and engine components have on the wear parameters.