Standard Diesel Research Articles

Effects of open combustion chamber geometries on the performance of pongamia biodiesel in a DI diesel engine

The present work investigates the effect of varying the combustion chamber geometry on the performance of a diesel engine using biodiesel in terms of brake specific fuel consumption, brake thermal efficiency as well as exhaust emissions and combustion characteristics. Engine tests have been carried out using a blend of 20% Pongamia Oil Methyl Ester (POME) with standard diesel as fuel and with three types of combustion chambers namely Hemispherical combustion chamber, Toroidal combustion chamber and Shallow depth combustion chamber without altering the compression ratio of the engine. The test results showed that brake thermal efficiency for toroidal combustion chamber is higher than for the other two types of combustion chambers. Significant improvement in reduction of particulates, carbon monoxide and unburnt hydrocarbons is observed for toroidal combustion chamber compared to the other two. However oxides of nitrogen were slightly higher for toroidal combustion chamber. The combustion analysis shows improved characteristics for toroidal combustion chamber compared to baseline engine at all loads of operation.

The biological effects of subacute inhalation of diesel exhaust following addition of cerium oxide nanoparticles in atherosclerosis-prone mice

BackgroundCerium oxide (CeO2) nanoparticles improve the burning efficiency of fuel, however, little is known about health impacts of altered emissions from the vehicles. MethodsAtherosclerosis-prone apolipoprotein E knockout (ApoE−/−) mice were exposed by inhalation to diluted exhaust (1.7mg/m3, 20, 60 or 180min, 5 day/week, for 4 weeks), from an engine using standard diesel fuel (DE) or the same diesel fuel containing 9ppm cerium oxide nanoparticles (DCeE). Changes in hematological indices, clinical chemistry, atherosclerotic burden, tissue levels of inflammatory cytokines and pathology of the major organs were assessed. ResultsAddition of CeO2 to fuel resulted in a reduction of the number (30%) and surface area (10%) of the particles in the exhaust, whereas the gaseous co-pollutants were increased (6–8%). There was, however, a trend towards an increased size and complexity of the atherosclerotic plaques following DE exposure, which was not evident in the DCeE group. There were no clear signs of altered hematological or pathological changes induced by either treatment. However, levels of proinflammatory cytokines were modulated in a brain region and liver following DCeE exposure. ConclusionsThese results imply that addition of CeO2 nanoparticles to fuel decreases the number of particles in exhaust and may reduce atherosclerotic burden associated with exposure to standard diesel fuel. From the extensive assessment of biological parameters performed, the only concerning effect of cerium addition was a slightly raised level of cytokines in a region of the central nervous system. Overall, the use of cerium as a fuel additive may be a potentially useful way to limit the health effects of vehicle exhaust. However, further testing is required to ensure that such an approach is not associated with a chronic inflammatory response which may eventually cause long-term health effects.

Comparative analysis of biodiesel–ethanol–diesel and biodiesel–methanol–diesel blends in a diesel engine

In this work, standard diesel fuel, biodiesel (45%)–methanol (10%)–diesel (45%), biodiesel (40%)–methanol (20%)–diesel (40%), biodiesel (45%)–ethanol (10%)–diesel (45%) and biodiesel (40%)–ethanol (20%)–diesel (40%) blends are tested in a compression ignited engine under the same operating conditions. Performance and emission characteristics of the engine fueled with biodiesel–methanol–diesel (BMD) and biodiesel–ethanol–diesel (BED) are compared to standard diesel fuel as the baseline. Overall, biodiesel–alcohol–diesel blends show a higher brakespecific fuel consumption than diesel. As alcohol concentrations in blends increase, CO and HC emissions increase, while NO emissions are reduced. Also, methanol blends are more effective than ethanol blends for reducing CO and HC emissions, while NO reduction is achieved by ethanol blends.

Improving the usability of vegetable oils as a fuel in a low heat rejection diesel engine

Usability of a waste vegetable oil in coated diesel engines was experimentally investigated. Waste corn oil was blended with petroleum diesel fuel by ratios of 15% corn oil to %85 diesel fuel (B15), 35% corn oil to %65 diesel fuel (B35) and 65% corn oil to %35 diesel fuel (B65). The surfaces of the engine piston and both intake and exhaust valves were coated with ZrO2 layer in order to make the combustion chamber insulated. Thus heat transfer through the combustion chamber was aimed to be reduced with the purpose of increasing the thermal efficiency and performance of the engine and also maintain the usability of vegetable oil in diesel engines. B15, B35, B65 and standard diesel fuels were used in the coated test engine. Performance parameters and exhaust emissions characteristics of all the above mentioned fuels were clarified and compared with uncoated engine test values of normal diesel fuel. It is believed that the main purpose of this study has been achieved as the engine performance parameters such as power and torque of the engine were increased with simultaneous decreases in the brake specific fuel consumption (bsfc). Besides, many of exhaust emission parameters such as CO, HC, and smoke opacity were decreased.

Exhaust emissions from liquid fuel micro gas turbine fed with diesel oil, biodiesel and vegetable oil

Micro gas turbine units are reliable and versatile units for on-site combined heat and power production (CHP). Compared to internal combustion engines, CHP units based on micro gas turbines offer several advantages, among which the compactness, the high power-to-weight ratio, the lower pollutant emissions and maintenance costs. Depending on the specific type of gas turbine, also fuel flexibility could be better than diesel engines, as the fuel is continuously burnt in a hot environment and there is not possible mixing among fuel and lubricating oil. Within the framework of the EU-Russian Federation FP7 cooperative and specifically the Bioliquids-CHP project, a Garrett GTP 30–67 liquid fuel (diesel) micro gas turbine was characterised with diesel and then tested with different first generation biofuels, such as vegetable oil and biodiesel. An in-house test bench was designed, engineered, instrumented and built. In this research work, exhaust emissions from experimental campaign on the micro gas turbine run with diesel oil and biofuels are presented. Emissions were measured at various load. The experiments demonstrated that the MGT can be successfully operated with these biofuels, with emissions comparable to the standard diesel oil. The experiences gained on the operation of the micro gas turbine on first generation biofuels will serve as a basis for modifying the MGT to be operated with bio-oil from fast pyrolysis.

Evaluation of the Thermal NO formation mechanism under low-temperature diesel combustion conditions

Over the past two decades, the amount of exhaust gas pollutants emissions has been significantly reduced due to the severe emission legislation imposed in most countries worldwide. Initial strategies simply required the employment of simple after-treatment and engine control devices; however, as the restrictions become more stringent, these strategies are evolving in the development of different combustion modes, specially characterized by having low-temperature combustion characteristics. These new working conditions demand the need to check the suitability of the current NO predictive models that coexist nowadays under standard diesel combustion characteristics, paying closer attention to the Thermal mechanism. In order to do so, a common chemical-kinetic software was employed to simulate, for n-heptane and methane fuels, fixed local conditions (standard diesel and low-temperature combustion) described by constant pressure, relative mixture fraction, oxygen mass fraction and initial and final reaction temperature. The study reflects a common trend between all the studied cases, independently of the considered local conditions, making it applicable to more complex situations such as real NO formation processes in diesel sprays. This relationship was characterized by a fourth-degree polynomial equation capable of substantially improving the NO prediction by just using the Thermal NO predictive model.

Omnigen: Providing electricity, food preparation, cold storage and pure water using a variety of local fuels

We describe a polygeneration system that can run on neat plant oils, such as Jatropha and Pongamia, or standard diesel fuel. A prototype has been constructed using a compression ignition engine of 9.9 kW shaft output. It consumes 3 L/h of fuel and will produce 40 kg/h of ice by means of an adsorption refrigerator powered from the engine jacket heat. Steaming of rice, deep and shallow frying, and other types of food preparation heated by the exhaust gas have been demonstrated. In addition, the feasibility of producing distilled water by means of multiple-effect distillation powered by the engine waste heat is shown. Overall plant efficiency and potential savings in greenhouse gas emissions are discussed.

Performance of Diesel Engine Fuelled by a Biodiesel Extracted From A Waste Cocking Oil

In this study, the combustion characteristics and emissions of compression ignition diesel engine were measured using a biodiesel as an alternative fuel. The tests were performed in Chemical and Mechanical Engineering department laboratories at steady state conditions for a four stroke single cylinder diesel engine loaded at variable engine speed between 1200-2600rpm. The waste vegetable oil (cocking oil) used in this investigation transferred from Tafila Technical University restaurant collected and disposed in a suitable way. The testing results show without any modification to diesel engine, under all conditions dynamical performance kept normal, and the B20, B5 blend fuels (include 20%, 5% biodiesel respectively) led to satisfactory emissions at variable load. The experimental results compared with standard diesel show that biodiesel provided significant reductions in CO, and unburned HC, but the NOx was increased. Biodiesel has a 5.95% increasing in brake-specific fuel consumption due to its lower heating value. However, using B20 and B5 diesel fuel gave better emission results, NOx and brake-specific fuel consumption.The experimental results show that the fuel consumption rate, brake thermal efficiency, and exhaust gas temperature increased while the bsfc, emission indices of CO2, CO decreased with an increase of engine speed. Moreover, the engine power increased when increasing the biodiesel percentage varied from 1.23 to 3.2 for standard diesel while for B20 between 1.5 to 3.47.while brake specific energy consumption varied between 16.8 to 13.81MJ/kW.kg for standard diesel, but for B5 found to be between 16.3 to 13MJ/kW.kg. In particular, biodiesel produced with the addition of the peroxidation process had the lowest equivalence ratio and emission indices of CO2, CO. The emission of NOx among all of the test fuels found to be increased when using B5 and B20 instead of standard diesel and these results validate the data recorded by other previous work. Therefore, the peroxidation process can be used effectively to improve the fuel properties and reduce emissions when biodiesel is used.

Physical Properties of Hydrocarbon Oils Produced by Botryococcus Braunii: Density, Kinematic Viscosity, Surface Tension, and Distillation Properties

In automotive engine combustion, particularly in case of compression ignition in diesel engines, physical properties of the fuel have a direct impact on the spray combustion process. The density, kinematic viscosity, surface tension, and distillation properties of triterpenic hydrocarbons extracted from the BOT-22 strain of Botryococcus braunii (called Bot-oil) were measured, and these properties were compared with those of standard diesel fuel. The density and surface tension of Bot-oil were almost the same as those of the diesel fuel. However, the kinematic viscosity of Bot-oil was 55 to 58 cSt at room temperature, which was 16 times higher than that of the diesel fuel. In addition, the distillation temperature of Bot-oil was approximately 430 °C, which was over 100 °C higher than that of the diesel fuel. To attain the properties required for fuel, a cracking technology for Bot-oil must be established.

Numerical analysis of injector flow and spray characteristics from diesel injectors using fossil and biodiesel fuels

The aim of the paper is the comparison of the injection process with two fuels, a standard diesel fuel and a pure biodiesel, methyl ester of soybean oil. Multiphase cavitating flows inside injector nozzles are calculated by means of unsteady CFD simulations on moving grids from needle opening to closure, using an Eulerian–Eulerian two-fluid approach which takes into account bubble dynamics. Afterward, spray evolutions are also evaluated in a Lagrangian framework using results of the first computing step, mapped onto the hole exit area, for the initialization of the primary breakup model.Two nozzles with cylindrical and conical holes are studied and their behaviors are discussed in relation to fuel properties.Nozzle flow simulations highlighted that the extent of cavitation regions is not much affected by the fuel type, whereas it is strongly dependent on the nozzle shape. Biodiesel provides a slightly higher mass flow in highly cavitating nozzles. On the contrary using hole shaped nozzles (to reduce cavitation) diesel provides similar or slightly higher mass flow. Comparing the two fuels, the effects of different viscosities and densities play main role which explains these behaviors.Simulations of the spray evolution are also discussed highlighting the differences between the use of fossil and biodiesel fuels in terms of spray penetration, atomization and cone-angle. Usage of diesel fuel in the conical convergent nozzle gives higher liquid penetration.

Analysis of operating a diesel engine on biodiesel-ethanol and biodiesel-methanol blends

In this work, standard diesel, neat biodiesel, biodiesel(85%)-methanol(15%) (B85M15) and biodiesel(85%)-ethanol(15%) (B85E15) fuels are tested. Experiments are carried out using a two-cylinder, 4-cycle, direct injected, water-cooled diesel engine at five loads between no load and a full load of 3000 rpm. Performance and emission characteristics of the engine fueled with biodiesel-ethanol and biodiesel-methanol blends were compared to neat biodiesel and standard diesel fuel as the baseline fuels. Overall, biodiesel-alcohol blends, as compared to diesel, reduce NO emissions while increasing CO and HC emissions, at below 70% loads. It is also shown that biodiesel-ethanol blend is more effective than biodiesel-methanol for emission reduction and overall engine performance.

Methyl ester of Sal oil (Shorea robusta) as a substitute to diesel fuel—A study on its preparation, performance and emissions in direct injection diesel engine

Many research reported vegetable oil as a potential substitute for diesel engines with its ester form known as biodiesel. The biodiesel can be prepared by different process using vegetable oil and alcohol. The common process used for biodiesel preparation is known as transesterification. This paper presents the transesterification of Sal oil (Shorea robusta) into Sal oil methyl ester (SOME) and its performance in direct injection diesel engine. Several process parameters such as catalyst quantity, molar ratio of alcohol, reaction temperature and reaction time were studied and the optimized process conditions are amount of catalyst (NaOH) – 0.25wt%, alcohol (methanol) – 150% excess, reaction temperature – 65°C and reaction time – 1.5h. The studies with SOME as fuel in the direct injection diesel engine shows that the exhaust emissions such as CO, HC and NOx are reduced by 25%, 45% and 12%, respectively compared to diesel without significant difference in thermal efficiency. Based on this study it is concluded that the SOME can be used as fuel without any modifications in the engine and hence this biodiesel can be a potential substitute to standard diesel fuel.

Performance and emission characteristics of a diesel engine fuelled with biodiesel–ethanol and biodiesel–methanol blends at elevated air temperatures

Effects of intake preheat engine on performance and emissions of a compression ignition engine running on biodiesel (85%)–alcohol (15%) fuels were investigated and compared to baseline results of standard diesel and neat biodiesel. Emissions were compared at two elevated intake air temperature and results indicate that high heat of vaporization of alcohol fuels affect emissions significantly. Intake air preheat was proved to be one of the effective solutions to reduce CO and HC emissions. Reduction of alcohol concentration in biodiesel–alcohol blends also showed similar effects to preheating intake air temperature.

Effects of intake air preheat and fuel blend ratio on a diesel engine operating on biodiesel–methanol blends

Effects of intake air preheat were investigated on performance and emissions of a compression ignition engine running on fuel concentrations of biodiesel (85%)–methanol (15%), biodiesel (90%)–methanol (10%), biodiesel (95%)–methanol (5%), neat biodiesel (B100). Fuels were evaluated in the engine at two elevated intake air temperatures at 30°C and 85°C. Neat biodiesel and standard diesel fuels were used in the engine at the ambient air temperature. Performance and emissions of the diesel engine are compared based on biodiesel–methanol blends, neat biodiesel and standard diesel. The resulting emissions indicate that the high heat of vaporization of methanol affects CO and HC emissions significantly. Preheating the intake air or lowering the methanol concentration in biodiesel–methanol blends tends to reduce the production of CO and HC while increasing NO emission.

Using one-dimensional modeling to analyse the influence of the use of biodiesels on the dynamic behavior of solenoid-operated injectors in common rail systems: Detailed injection system model

A combined experimental and computational investigation has been performed in order to evaluate the influence of physical properties of biodiesel on the injection process in a common-direct injection system with second generation solenoid injectors. For that purpose, after a complete characterization of the system, which involved mechanical and hydraulic characterization, a one-dimensional model has been obtained and extensively validated. Simulations have then been performed with a standard diesel and a 100% rape methyl ester (RME) biodiesel which allowed a comparison and analysis of the dynamic response of the injector to be done. Different injection strategies involving main injection and main plus post-injection have been used to explore the impact of the use of biodiesel on the performance and stability of solenoid injectors. As far as the dynamic response of the injector is concerned, the results obtained have clearly shown that the use of biodiesel affects the dynamic response of the needle, especially at low injection pressures. The behavior of the system under multi-injection strategies (main plus post-injection) has been also evaluated determining for different operating conditions (injection pressures and backpressures) the minimum dwell time between injections to assure a stable behavior in the injection process (mass flow rate). Important differences have been found between biodiesel and standard diesel in this critical parameter at low injection pressures, becoming less important at high injection pressure. Finally, a modification on the injector hardware has been proposed in order to compensate these differences.

Using one-dimensional modeling to analyze the influence of the use of biodiesels on the dynamic behavior of solenoid-operated injectors in common rail systems: Results of the simulations and discussion

The influence of using biodiesel fuels on the hydraulic behavior of a solenoid operated common rail injection system has been explored by means of a one-dimensional model. This model has been previously obtained, including a complete characterization of the different components of the injector (mainly the nozzle, the injector holder and the electrovalve), and extensively validated by means of mass flow rate results under different conditions. After that, both single and multiple injection strategies have been analyzed, using a standard diesel fuel and rapeseed methyl ester (RME) as working fluids. Single long injections allowed the characterization of the hydraulic delay of the injector, the needle dynamics and the discharge capability of the couple injector-nozzle for the two fuels considered. Meanwhile, the effect of biodiesel on main plus post injection strategies has been evaluated in several aspects, such as the separation of the two injections or the effect of the main injection on the post injection fueling. Finally, a modification in the injector hardware has been proposed in order to have similar performances using biodiesel as the original injector configuration using standard diesel fuel.

Improved efficiency of extraction of polycyclic aromatic hydrocarbons (PAHs) from the National Institute of Standards and Technology (NIST) Standard Reference Material Diesel Particulate Matter (SRM 2975) using accelerated solvent extraction

The efficiency of extraction of polycyclic aromatic hydrocarbons (PAHs) with molecular masses of 252, 276, 278, 300, and 302 Da from standard reference material diesel particulate matter (SRM 2975) has been investigated using accelerated solvent extraction (ASE) with dichloromethane, toluene, methanol, and mixtures of toluene and methanol. Extraction of SRM 2975 using toluene/methanol (9:1, v/v) at maximum instrumental settings (200 °C, 20.7 MPa, and five extraction cycles) with 30-min extraction times resulted in the following elevations of the measured concentration when compared with the certified and reference concentrations reported by the National Institute of Standards and Technology (NIST): benzo[b]fluoranthene, 46%; benzo[k]fluoranthene, 137%; benzo[e]pyrene, 103%; benzo[a]pyrene, 1,570%; perylene, 37%; indeno[1,2,3-cd]pyrene, 41%; benzo[ghi]perylene, 163%; and coronene, 361%. The concentrations of the following PAHs were comparable to the reference values assigned by NIST: indeno[1,2,3-cd]fluoranthene, dibenz[a,h]anthracene, and picene. The measured concentration of dibenzo[a,e]-pyrene was lower than the information value reported by the NIST. The measured concentrations of other highly carcinogenic PAHs (dibenzo[a,l]pyrene, dibenzo[a,i]pyrene, and dibenzo[a,h]pyrene) in SRM 2975 are also reported. Comparison of measurements using the optimized ASE method and using similar conditions to those applied by the NIST for the assignment of PAH concentrations in SRM 2975 indicated that the higher values obtained in the present study were associated with more complete extraction of PAHs from the diesel particulate material. Re-extraction of the particulate samples demonstrated that the deuterated internal standards were more readily recovered than the native PAHs, which may explain the lower values reported by the NIST. The analytical results obtained in the study demonstrated that the efficient extraction of PAHs from SRM 2975 is a critical requirement for the accurate determination of PAHs with high molecular masses in this standard reference material and that the optimization of extraction conditions is essential to avoid underestimation of the PAH concentrations. The requirement is especially relevant to the human carcinogen benzo[a]pyrene, which is commonly used as an indicator of the carcinogenic risk presented by PAH mixtures.

ETHANOL–BIODIESEL–DIESEL BLENDS AS A DIESEL EXTENDER OPTION ON COMPRESSION IGNITION ENGINES

Increasing fuel demand, decreasing natural reserves and environmental consciousness have together led to testing and implementing new fuels and blending components of compression ignition engines. Biofuels are very commonly added to fossil fuels, mostly ethanol to gasoline and FAME to diesel. Harmonizing their properties with engines is a great challenge for automotive and oil industry. Increasing demand for diesel oil in Europe raised the question about the possibility of increasing the amount of bio extenders. There were and certainly there are a number of experiments aimed at substituting or blending diesel with other fuels. One group of such fuels makes bioethanol– biodiesel–diesel oil mixtures. The paper proposes a global overview on literature and presents the obtained results. The article explores the possibility of using bioethanol–biodiesel–diesel oil mixtures in vehicles and agricultural compression ignition engines. The main aspect of researches was to find blends substitutable for compression ignition engines. Investigations were made to determine the maximum volume of a renewable part thus reaching the same or similar power output with lowering emissions. The received results were used for environmental and economical investigations. The valorisation of the results shows that bioethanol–biodiesel–diesel blends fulfil the cetane number, viscosity and lubricity requirements for standard diesel. Practical measurements and engine tests show that the utilization of a new fuel decreases emissions from the engine. The results of agricultural feedstock calculation indicate that in Hungary the biofuel part of the investigated fuels can be produced from an overflow.

An experimental investigation on effects of methanol blended diesel fuels to engine performance and emissions of a diesel engine

Considering strict restrictions on exhaust emissions of newly produced diesel engines, in this study, the effects of methanol and diesel fuel blends on compression ignition engine performance and exhaust emissions of a four cylinder, four stroke, direct injection, turbocharged diesel engine were experimentally investigated. Methanol-blended diesel fuels were ranged from 0 to 15% volumetric methanol content with an increment of 5%. The tests were performed by varying engine speed between 1000 min-1 to 2700 min-1 by an engine testing dynamometer. Results indicated that brake specific fuel consumption and nitrogen oxide emissions increased while brake thermal efficiency, carbon monoxide and hydrocarbons decreased relative to single diesel fuel operation with increasing amount of methanol in the fuel mixture. Effects can be visualized by data which were 49 and 47.5 kW for power, 169 and 190 g/kWh for brake specific fuel consumption, 33 and 30% for brake specific thermal efficiency, 0.21 and 0.18% for carbon monoxide, 7.15 and 8.1% for carbon dioxide, 8.02 and 6.1 ppm for hydrocarbons, 385 and 418 ppm for nitrogen oxides at 1600 min-1 in order of standard diesel fuel operation and fuel blend with 10% methanol content. Key words: Methanol, diesel fuel, compression ignition, duel fuel, exhaust emission, emission reduction, combustion.

A Performance, Emission and Combustion Investigation on Hot Air Assisted Eucalyptus Oil Direct Injected Compression Ignition Engine

A diesel engine modified for eucalyptus oil direct injection (EuDI) has been tested to study eucalyptus oil behavior. Since the eucalyptus oil possesses low cetane number fails to auto ignite, the test engine was modified to supply hot air during suction stroke which helps to auto-ignite the injected eucalyptus oil. The engine with this facility was operated using eucalyptus oil under various load conditions and at various intake temperatures. The results of the investigation were proved that eucalyptus oil could be direct injectable in a regular diesel engine after little engine modification. This method showed almost same brake thermal efficiency (BTE) at full load compared to standard diesel operation. Except NOx emission other emissions were found closer to diesel baseline operation. This mode offered almost 50% smoke free operation at all loads compared to standard diesel operation. Also this method successfully proved the complete replacement of diesel fuel by eucalyptus oil.