Indirect Injection Engine Research Articles

Impact of using adulterated automotive diesel on the exhaust emissions of a stationary diesel engine

The EU Directives and legislation by worldwide environmental authorities impose constantly lower levels for the airborne pollutant emissions of internal combustion engines towards the goal of zero emission vehicles. During the last decade, engine manufacturers, refiners and fuel companies invest highly in order to comply with the increasingly severe emission requirements. The diesel engine is widely used for transportation, manufacture, power generation, construction and farming operations. There are different kinds of diesel engine depending on their application: small, high speed, indirect-injection engines or low speed, direct -injection behemoths with cylinders more than one meter in diameter. Their main advantages are the efficiency, economy and reliability. The physicochemical properties of the diesel fuels and the engine design affect the operability, the efficiency and the performance of the diesel engine and they correlate to the exhaust emissions. In Greece, the diesel fuel market steadily increases during the last years. The fuels produced by the refineries usually comply with the existing specifications. However, alterations in the fuel properties may occur through the supply chain to the service stations due to failures of the distribution system (i.e. contamination with water, tank sludge and residues) or adulteration with lower value and taxation fuels (heating oil, marine diesel or industrial solvents). The transportation sector is a major source of air pollution. It contributes to harmful exhaust emissions, such as greenhouse gas emissions, carbon monoxide, sulfur oxides (SOx), nitrogen oxides (ΝΟx), unburned hydrocarbons (HC) and particulate matter (PM) emissions. In this paper, PM and exhaust emissions from a stationary single cylinder diesel engine were examined. For comparison purposes, tests were carried out with a typical automotive diesel fuel of the Greek market and with adulterated fuels with heating oil or white spirit. The noncomplying diesel fuels gave increased emissions in all cases with only exception the PM emissions due to adulteration with white spirit. More specifically, the experimental results for the adulterated fuels with heating diesel showed an increase of the nitrogen oxide emissions up to 73.9%, of the unburned hydrocarbons up to 29.6% and of PM up to 121% compared to the baseline diesel fuel emissions.

Research on Match of Swirl-chamber and Conical Spray in Indirect Injection Engine

Swirl-chamber diesel engine has the advantages of lower NOx emission and noise, but the deficiency of comparatively higher fuel consumption rate constrains its further development. In order to improve the fuel economy of a swirl-chamber diesel engine, the engine was modified by applying a conical spray injector in the swirl-chamber to improve its fuel-air mixture formation and combustion processes. In addition, a series of swirl-chamber schemes were designed, and the match of the conical spray with these swirl-chamber schemes were investigated with the aid of a 3-D CFD software package. The measurement and simulation results indicate that with the application of the conical spray to the prototype engine, the fuel economy is improved. Meanwhile, one of the modification schemes on the swirl-chamber presents the potential to further improve the fuel economy of the engine thanks to its more homogeneous fuel-air mixture compared with that of the original swirl-chamber.

The evaluation of cycle by cycle mixture composition in an indirect injection engine

The investigations on an indirect injection unsupercharged engine fitted with a two state oxygen sensor have shown a particularly high fluctuation of mixture composition in transient states of the engine, represented by the rev up and rev down of the engine without a load and with a steady load. The spread of the maximum and average cycle by cycle mixture compositions in these states determined by a method developed by the authors (this method shall be a subject of a separate publication) is larger if the engine load is lower. It has been proved that the biggest fluctuation of the mixture composition occurs in the first part of the rev down phase i.e. in the phase of stepwise throttle closing when the injectors are still activated. In steady states represented by typical operating states of the engine the highest fluctuation of the mixture composition occurs at high engine speeds and low engine loads, and the lowest at low engine speeds and high engine loads. It has been confirmed that the fluctuation of the cycle by cycle mixture composition in the transient states is almost one order of magnitude larger than in the steady states. The investigations have been performed on a 1.6l Euro 3 engine fitted with a control unit made by a reputable manufacturer.

Combustion analysis of preheated crude sunflower oil in an IDI diesel engine

In this study, preheated crude sunflower oil (PCSO) was tested for combustion and emission properties against petroleum based diesel fuel (PBDF) in a naturally aspirated, indirect injection (IDI) engine. The cylinder gas pressure and heat release curves for PCSO at 75 °C were similar to those of PBDF. The ignition delays for the PCSO were longer and the start of injection timing was earlier than for PBDF. The difference in the average brake torque was a decrease of 1.36% for PCSO though this was statistically insignificant. The brake specific fuel consumption increased by almost 5% more or less in proportion to the difference in calorific value, so that the 1.06% increase in thermal efficiency was again statistically insignificant. The emission test results showed that the decreases in CO2 emissions and smoke opacity 2.05% and 4.66%, respectively; however, this was not statistically significant, though in line with the apparent increase in thermal efficiency. There was a significant 34% improvement in the emissions of unburnt hydrocarbons. Carbon monoxide increased by 1.77% again the result was not statistically significant given the small number of repeat tests. The use of PCSO does not have any negative effects on the engine performance and emissions in short duration engine testing.

Summary of a 12-Year Experiment in the Use of 50% RME Fuel Mixture in Heavy Trucks and Light Vehicles

Experiments on the use of a 50% RME (Rapeseed Oil Methyl Ester ) fuel mixture were conducted at the agricultural cooperative “Champagne Cereales”, over the period 1993-2005. The study was carried out on twenty heavy trucks from EURO 0 to EURO 3 standards, ten light vehicles with indirect injection engines and four light vehicles (“Peugeot 406” and “Citroen C5”) equipped with “common rail” engine and with DPF (diesel particulate filter ). Half of these vehicles used RME50 fuel and performed the same services along with another group of reference vehicles running on standard diesel fuel. The mileage run on RME50 by heavy trucks ranged between 230 000 and 530 000 km. “406” sedan mileage exceeded 230 000 km and “C5” 190 000 km. Consumption was recorded and lubricants were analysed over the twelve-year period. Injection systems were examined and ten heavy truck engines were disassembled for wear and deposits assessment. The use of RME resulted in no notable incident, and its effect on consumption was according to LHV (lower heating value ) variation. Lubricant dilution was observed on some vehicles, and this phenomenon was reinforced by the use of RME. The lower viscosity level did not cause any increase of wear. The assessed engines showed no sign of deposits in rings and crankcases. On the other hand, the use of RME reduced wear on certain heavy trucks due to lower soot contents in the lubricant.

The effects of injection timing on NO x emissions of a low heat rejection indirect diesel injection engine

Higher NO x is one of the major problems to be overcomed in a low heat rejection (LHR) diesel engine as insulation leads to an increase in combustion temperature about 200–250 °C compared to an identical standard (STD) diesel engine. High combustion temperatures alter optimum injection timing of a LHR engine. With the proper adjustment of the injection timing, it is possible to partially offset the adverse effect of insulation on heat release rate and hence to obtain improved performance and lower NO x . However, the injection timing and brake specific fuel consumption (BSFC) trade-off must be considered together in performance and NO x emission point of view. In this study, optimum injection timing was found with 4 crank angle (34° CA) retarded before top dead centre (BTDC) in LHR diesel engine in comparison to that of STD diesel engine (38° CA BTDC). When the LHR engine was operated with the injection timing of the 38 crank angle, which is the optimum value of the STD engine, it was shown that NO x emission increased about 15%. However, when the injection timing was retarded to 34° CA in the LHR case, it was observed a decrease on the NO x emissions with about 40% and the brake specific fuel consumption (BSFC) with about 6% compared to that of the STD case. Thus, by retarding the injection timing, an additional 1.5% saving in fuel consumption was obtained.

Characterization of diesel particles: effects of fuel reformulation, exhaust aftertreatment, and engine operation on particle carbon composition and volatility.

Diesel exhaust particles are the major constituent of urban carbonaceous aerosol being linked to a large range of adverse environmental and health effects. In this work, the effects of fuel reformulation, oxidation catalyst, engine type, and engine operation parameters on diesel particle emission characteristics were investigated. Particle emissions from an indirect injection (IDI) and a direct injection (DI) engine car operating under steady-state conditions with a reformulated low-sulfur, low-aromatic fuel and a standard-grade fuel were analyzed. Organic (OC) and elemental (EC) carbon fractions of the particles were quantified by a thermal-optical transmission analysis method and particle size distributions measured with a scanning mobility particle sizer (SMPS). The particle volatility characteristics were studied with a configuration that consisted of a thermal desorption unit and an SMPS. In addition, the volatility of size-selected particles was determined with a tandem differential mobility analyzer technique. The reformulated fuel was found to produce 10-40% less particulate carbon mass compared to the standard fuel. On the basis of the carbon analysis, the organic carbon contributed 27-61% to the carbon mass of the IDI engine particle emissions, depending on the fuel and engine operation parameters. The fuel reformulation reduced the particulate organic carbon emissions by 10-55%. In the particles of the DI engine, the organic carbon contributed 14-26% to the total carbon emissions, the advanced engine technology, and the oxidation catalyst, thus reducing the OC/EC ratio of particles considerably. A relatively good consistency between the particulate organic fraction quantified with the thermal optical method and the volatile fraction measured with the thermal desorption unit and SMPS was found.

The effect of elevated fuel inlet temperature on performance of diesel engine running on neat vegetable oil at constant speed conditions

The concept that engine design is all important in the use of vegetable oils as a diesel fuel has been pointed out by many researchers. One hundred percent of vegetable oil can be used safely in an indirect injection engine, but not in a direct injection engine due to the high degree of atomization required for this type. This problem is related to increasing droplet size on injection into the cylinder that results in poor combustion. This in turn, causes the formation of deposits in the combustion chamber, together with oil dilution due to introduction of unburnt fuel into the crankcase. The objective of this work was to evaluate the effect of increasing fuel inlet temperature on viscosity and performance of a single cylinder, unmodified diesel engine. The overall results showed that fuel heating increased peak cylinder pressure and was also beneficial at low speed and under part-load operation. The high combustion temperature at high engine speed becomes the dominant factor, making both heated and unheated fuel to acquire the same temperature before fuel injection.

Chemistry of diesel fuels

Section I.Introduction 1.Introduction to Chemistry of Diesel Fuels Section II.Characterization of Diesel Fuels 2.Molecular Characterization of Diesel Fuels Using Modern Analytical Techniques 3.Rapid Detailed Analysis of Transportation Fuels by GC-FIMS Section III.Production of Clean Diesel Fuesls 4.Catalytic Cracking of C6-C16 Paraffins and Cycloparaffins over a Mesoporous Zeolite-Unstacked H-MCM-22 5.The Use of Hydrocracking Process to Produce High Quality Diesel Oil From Brazil's High Nitrogen Feedstocks 6.H2S and Aromatic Effects on Hydrodesulfurization of Dibenzothiophenes over CoMo/C Catalyst 7.Novel Mesoporous Co-Mo/MCM-41 Catalysts for Deep Hydrodesulfurization for Diesel Fuels 8.Performance of Mo Catalysts Supported on TiO2- Based Binary Supports for Distillate Fuel Hydroprocessing 9.Preparation of Surfactants from a Product of Diesel Fuel Biodesulfurization 10.Synthesis of Low Nitrogen Cetane Improvers from the Nitration of Renewable Feedstocks Section V.Emissions and Reduction 11.The Effect of Dimethoxy Methane Fuel Additive on Particle Emissions from a Light Duty Diesel Vehicle 12.The Role of Hydrocarbon Reductant in Metal Loaded Zeolite DeNOx, Catalysis 13.Distribution of PAHS in Burn Residue and Differentiation of Pyrogenic and Petrogenic PAHS. The 1994 and 1997 Mobile Burn Study 14.The Use of Oxygenated Diesel Fuels for Reduction of Particulate Emissions from a Single-Cylinder Indirect Injection Engine 15.Catalytic Activity of Alkali Metal Salts Supported on Perovskite Type Oxide for Carbonaceous Materials Combustion. Author Index. Subject Index.

Particulate matter size distribution and associated polycyclic aromatic hydrocarbon content from indirect and direct injection diesel engines

Within the framework of atmospheric aerosol study, evaluation of the contribution of the particle source to global atmospheric pollution is a challenge that requires an improvement in the knowledge of particulate matter. As a part of this knowledge improvement, this study has been focused on particles emitted from diesel vehicles. Two light-duty diesel vehicles were studied for particulate matter size distribution and associated polycyclic aromatic hydrocarbon (PAH) content. A diffusional and inertial spectrometer was used, allowing particles from 7.5 nm to 15 μm to be collected and analysed. Teflon-coated glass fibre filters were employed as collector substrates, and weighed prior to and after sampling. Each of them was extracted with methylene chloride in an accelerated solvent extractor, cleaned on a silica gel micro-column and analysed for PAH by gas chromatography/mass spectrometry using internal standards for quantitation. Both analytical and sampling methods were validated. The highest particle mass was found to be emitted at 0.2 μm for the direct injection engine and 0.07 μm for the indirect injection engine. PAHs were found to be essentially distributed on particles in the accumulation mode, at about 0.2 μm, and high molecular weight PAH distributions were found to be bimodal or trimodal, depending on the engine injection.

Performance and Combustion Characteristics in a Methanol-Fueled IDI Engine.

Restraining the initial combustion, promoting the diffused combustion and reducing the cyclic combustion variation are of utmost importance to improving the fuel economy, exhaust gas emissions, and noise of the methanol fueled indirect injection (IDI) diesel engine. The author closely studied methanol fuel combustion in a high speed diesel engine (swirl-chamber system and single cylinder of 82.5mm bore and 92mm stroke), using different ignition systems, such as the spark-assisted method, glow-assisted method, and diesel fuel pilot injected method, to evaluate the engine performance and combustion characteristics. The methanol-fueled engine used in the study had a new combustion chamber with a refined jet passage for the optimum air discharge coefficient as well as for improved diffusion and penetration of jet in the main chamber. The engine cylinder was equipped with a miniature throttle nozzle for improved fuel injection characteristics. The new methanol-fueled combustion system was found to outperform the diesel-fueled conventional combustion system as regard the fuel consumption, smoke emission, and NOx emissions, regardless of which ignition system were employed.

A Study on the Effect of Recirculated Exhaust Gas with Scrubber EGR System upon Exhaust Emissions in Diesel Engines

The effects of recirculated exhaust gas on the characteristics of and soot emissions under a wide range of engine load have been experimentally investigated by a water-cooled, four-cylinder, indirect injection, four cycle and marine diesel engine operating at two kinds of engine speeds. The simultaneous control of and soot emissions in diesel engines is targeted in this study. The EGR system is used to reduce emissions, and a novel diesel soot removal device with a cylinder-type scrubber for the experiment system which has 6 water injectors(A water injector has 144 nozzles in 1.0 mm diameter) is specially designed and manufactured to reduce the soot contents in the recirculated exhaust gas to intake system of the engines. The intake oxygen concentration and the mean equivalence ratio calculated by the intake air flow and fuel consumption rate, and the exhaust oxygen concentration measured are used to analyse and discuss the influences of EGR rate on and soot emissions. The experiments are performed at the fixed fuel injection timing of BTDC regardless of experimental conditions. It is found that emissions are decreased and soot emissions are increased owing to the drop of intake oxygen concentration and exhaust oxygen concentration, and the rise of equivalence ratio as the EGR rate rises.

RESULTS OF ENGINE AND VEHICLE TESTING OF SEMIREFINED RAPESEED OIL

The renewed interest in environmentally compatible fuels has led to the choice of rapeseed oil as the main alternative to diesel fuel in Europe. Transesterified rapeseed oil (viz. rape methyl ester) has been the predominant vegetable oil fuel used because its characteristics are quite similar to diesel. However, it is an expensive product due to high feedstock costs. The objective of this research was to produce and test an economic and high quality nonesterified rapeseed oil suitable for use as a diesel fuel extender. This was achieved by acidified hot water degumming combined with filtration to five microns. This rapeseed oil, designated as a Semi Refined Oil (SRO), has a high viscosity in comparison with diesel (589 mPa·s vs 22 mPa·s at –12°C). Hence, SRO fuel can be used only as a diesel fuel extender at inclusion rates up to 25%, the resultant blend having a viscosity of 55 mPa·s at –12°C. When used with direct injection (DI) engines, power output (at 540 rpm at the power take-off shaft) was reduced by c. 0.06% for every 1% increase in SRO inclusion rate, and brake specific fuel consumption (BSFC) increased by c. 0.14%/1% increase in SRO inclusion rate (viz. a 25% SRO/diesel blend had a 1.5% decrease in power and a 3.5% increase in BSFC compared with diesel). These values are in accordance with the lower energy density of rapeseed oil fuels compared with diesel. Chemical and viscosity analyses of engine lubrication oil using both diesel and a 15% SRO inclusion rate (after c. 170 h/fuel tested), including metal contamination as an indicator of engine wear, showed that there was no measurable effect on engine lubricating oil due to SRO inclusion in diesel oil. However, the injector fouling results showed that shorter injector service intervals are required. In contrast to the DI results, above, when SRO was used to fuel indirect injection (IDI) engines, power was considerably reduced mainly due to inadequate air/fuel mixing. As most agricultural tractors are DI, SRO has a potential as a diesel fuel extender for agricultural equipment.

Influence of Parameters on the Errors of Heat Release Rates of Internal Combustion Engines with Divided Combustion Chambers.

Precise indicator diagrams are necessary for correct estimation of heat release rates or progression of combustion in both chambers of an indirect injection (IDI) engine. Many parameters, such as pressure and physical properties of the gas in the chambers, flow coefficient of the connecting passage, engine speed, and crank angle, influence the heat release if they contain errors. The authors have numerically estimated such influence in the form of error sensitivities. Calculations were made for three types of connecting passages of an IDI engine. Wiebe's function was used for fundamental heat release.

Comparative performance and emission studies when using olive oil as a fuel supplement in DI and IDI diesel engines

An experimental study is conducted to evaluate and compare the use of a diesel fuel supplement, specifically a 25/75% and a 50/50% blend of waste olive oil and commercial diesel fuel, in a four-stroke, DI (Direct Injection) diesel engine and in a four-stroke, IDI (Indirect Injection) diesel engine having a swirl-combustion chamber. The influence of the blends (diesel fuel+olive oil), for a large range of loads, has been examined on fuel consumption, maximum pressure, exhaust temperature, exhaust smokiness and exhaust-gas emissions such as nitrogen oxides (NOx), hydrocarbons (HC) and carbon monoxide (CO). The differences in the measured performance and exhaust-emission parameters, from the baseline operation of either engine, are determined and compared. The study shows, for both the DI and IDI engines, a small penalty in specific fuel consumption, a moderate increase in exhaust smokiness and essentially unaltered maximum pressures and exhaust temperatures when using the blends. Also, for both the IDI and DI engines when using the blends, the study shows moderate decreases in emitted nitrogen oxides and increases in hydrocarbons as well as negligible increases in emitted carbon monoxide. Theoretical aspects of diesel engine combustion are used to aid the interpretation of the observed engines' behaviour.

Particulate emissions from ‘in-use’ motor vehicles—II. Diesel vehicles

A detailed study has been undertaken of the exhaust particulate matter (EPM) emitted by 19 light-duty and 13 heavy-duty diesel vehicles. Eighteen of the light-duty vehicles were of the indirect injection types, whereas the heavy-duty ones were all four stroke. The light-duty vehicles were tested under a standard city drive cycle, the heavy-duty vehicles being subjected to a multi-mode test cycle. Although considerable variability was found in emission rates between individual vehicles of the same make and model, light-duty diesel vehicles emitted 3–6 g EPM kg −1 of fuel consumed, which was six times as much as spark ignition (S.I.) vehicles. The heavy-duty diesel vehicles emitted most EPM, giving rise to >6.6g EPM kg −1 on average. For both classes of diesel vehicles, higher EPM rates were generally associated with higher CO emission rates. Light-duty diesel EPM was found to consist mostly of C, two-thirds of which was in the ‘sooty’ or elemental (EC) form with the remainder organic (OC). The heavy-duty diesel EPM contained a higher proportion of OC than that from the light-duty diesels. Tests carried out with 13C-labelled lubricating oil indicated a significant oil contribution to EPM from diesel vehicles. In addition to measuring variations in EPM emission rates between different diesel vehicles, the influences of fuel supply, injection timing and fuel quality were also studied, using a light-duty indirect injection engine. Injection timing was found to have the greatest influence, with EPM emissions decreasing on retardation. The influence of injection timing was also assessed using a direct injection vehicle.

A High-Speed Direct Injection Diesel Engine for Passenger Cars

The paper describes the development of a high-speed direct injection (HSDI) diesel engine suitable for passenger car applications. The evolution from a low emissions medium-speed engine, through a four-cylinder 2.3 litre research engine, into a four-cylinder 2.0 litre production engine is presented. The challenge to the engineer has been to develop the HSDI engine to operate with acceptable noise, emissions, smoke and driveability over the wide speed range (up to 5000 r/min) required for passenger cars. The key element in this task was the optimization of the combustion system and fuel injection equipment. The HSDI is shown to have a significant fuel economy advantage over the prechamber indirect injection (IDI) engine. Future developments of the fuel injection system are described which will further enhance the HSDI engine and provide additional noise and emissions control.

The Ford 2.5 Litre Direct Injection Naturally Aspirated Diesel Engine

The advantages of a high-speed direct injection diesel over an indirect injection engine are well established. In the last decade many studies have been presented which suggest that most of the technical issues preventing operation at high speed have been overcome. The new Ford 2.5 litre engine introduces a first generation of production high-speed direct injection engines. Based on controlled high swirl air management, combined with high rates of fuel injection, the engine produces 52 kW at 4000 r/min. Initial installation of the 2.5 litre high-speed direct injection engine is in the Ford Transit range of vehicles where 25 per cent fuel economy improvements over its predecessor, the York 2.36 litre indirect injection engine, have been achieved. Designed to meet the demands of modern vehicle application, the engine includes many features to improve reliability and durability. This paper describes the engine systems and components of the engine, together with the key aspects of the performance development with specific reference to the actions employed to control noise.

A New Microprocessor-Based Automotive Diesel Pump Controller

A control system for a new diesel rotary distributor pump has been developed. The system is applied on multicylinder, indirect injection engines, both turbocharged and naturally aspirated. Precise, full authority control of fuel quantity and injection timing is the primary function of the system, with benefits to emissions, driveability rated output, and fuel economy. Idle speed governing, cruise control, and exhaust gas recirculation (EGR) control are important features. Transmission torque converter lockup is decided by the system for vehicles with automatic transmissions. Self-diagnostics are provided to assist servicing.

Paper 9: Fuel-Injection System Requirements for Different Engine Applications

Modern diesel engines are used in a wider variety of applications, installations, and environments than probably any other power unit. It is quite common for one engine type to be used for tractors, automotive, industrial, and marine purposes, with very little change to the basic engine. Considerable changes are necessary in the fuel-injection system, however, to meet the varying torque curve, speed range, and governing requirements. Operation over a wider range of temperatures and viscosities is often needed, and noise and smoke legislation have added further requirements. The paper outlines these problems and the compromises that must sometimes be made. Direct-injection and indirect-injection engine cases have been considered. The paper concludes with some comments on pre-setting fuel pumps for high-volume production.