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Experimental Study into a Hybrid PCCI/CI Concept for Next-Generation Heavy-Duty Diesel Engines

2012-06-18
This paper presents the first results of an experimental study into a hybrid combustion concept for next-generation heavy-duty diesel engines. In this hybrid concept, at low load operating conditions, the engine is run in Pre-mixed Charge Compression Ignition (PCCI) mode, whereas at high load conventional CI combustion is applied. This study was done with standard diesel fuel on a flexible multi-cylinder heavy-duty test platform. This platform is based on a 12.9 liter, 390 kW heavy-duty diesel engine that is equipped with a combination of a supercharger, a two-stage turbocharging system and low-pressure and high-pressure EGR circuitry. Furthermore, Variable Valve Actuation (VVA) hardware is installed to have sufficient control authority. Dedicated pistons, injector nozzles and VVA cam were selected to enable PCCI combustion for a late DI injection strategy, free of wall-wetting problems.
Video

DPF's Regeneration Procedures and Emissions with RME Blend Fuels

2012-06-18
The fatty acid methyl esters (FAME's) - in Europe mostly RME (Rapeseed methyl ester) - are used in several countries as alternative biogene Diesel fuels in various blending ratios with fossil fuels (Bxx). Questions often arise about the influences of these biocomponents on the modern exhaust aftertreatment systems and especially on the regeneration of Diesel particle filters (DPF). In the present work different regeneration procedures of DPF systems were investigated with biofuels B0, B20 & B100. The tested regeneration procedures were: passive regenerations: DOC + CSF; CSF alone, active regenerations: standstill burner; fuel injections & DOC. During each regeneration on-line measurements of regulated and unregulated emission components (nanoparticles & FTIR) were conducted. It can be stated that the increased portion of RME in fuel provokes longer time periods to charge the filter with soot.
Video

Impact of Biodiesel on Particle Emissions and DPF Regeneration Management in a Euro5 Automotive Diesel Engine

2012-06-18
Biofuel usage is increasingly expanding thanks to its significant contribution to a well-to-wheel (WTW) reduction of greenhouse gas (GHG) emissions. In addition, stringent emission standards make mandatory the use of Diesel Particulate Filter (DPF) for the particulate emissions control. The different physical properties and chemical composition of biofuels impact the overall engine behaviour. In particular, the PM emissions and the related DPF regeneration strategy are clearly affected by biofuel usage due mainly to its higher oxygen content and lower low heating value (LHV). More specifically, the PM emissions and the related DPF regeneration strategy are clearly affected by biofuel usage due mainly to its higher oxygen content and lower low heating value, respectively. The particle emissions, in fact, are lower mainly because of the higher oxygen content. Subsequently less frequent regenerations are required.
Video

An Experimental Analysis on Diesel/n-Butanol Blends Operating in Partial Premixed Combustion in a Light Duty Diesel Engine

2012-06-18
This paper reports results of an experimental investigation performed on a commercial diesel engine supplied with fuel blends having low cetane number to attain a simultaneous reduction in NOx and smoke emissions. Blends of 20% and 40% of n-butanol in conventional diesel fuel have been tested, comparing engine performance and emissions to diesel ones. Taking advantage of the fuel blend higher resistance to auto ignition, it was possible to extend the range in which a premixed combustion is achieved. This allowed to match the goal of a significant reduction in emissions without important penalties in fuel consumption. The experimental activity was carried on a turbocharged, water cooled, 4 cylinder common rail DI diesel engine. The engine equipment included an exhaust gas recirculation system controlled by an external driver, a piezo-quartz pressure transducer to detect the in-cylinder pressure signal and a current probe to acquire the energizing current to the injector.
Video

Impact of Auxiliary Loads on Fuel Economy and Emissions in Transit Bus Applications

2012-05-25
In this paper we present the results of full-scale chassis dynamometer testing of two hybrid transit bus configurations, parallel and series and, in addition, quantify the impact of air conditioning. We also study the impact of using an electrically controlled cooling fan. The main trend that is noted, and perhaps expected, is that a significant fuel penalty is encountered during operation with air conditioning, ranging from 17-27% for the four buses considered. The testing shows that the series hybrid architecture is more efficient than the parallel hybrid in improving fuel economy during urban, low speed stop and go transit bus applications. In addition, smart cooling systems, such as the electrically controlled cooling fan can show a fuel economy benefit especially during high AC (or other increased engine load) conditions.
Technical Paper

Standard Rating Needed for Fuels for High-Speed Oil-Engines

1933-01-01
330002
ONCE a method for standard Diesel-fuel knock-rating has been established, a standard for Diesel-fuel specifications should be set which will cover standard knock-rating, gravity, viscosity, pour point, Conradson carbon, water, sediment and sulphur content. The last three items have an important influence on the wear and depreciation of the engine as well as on the carbon formation in the combustion chamber. The foregoing conclusions are reached after the author has treated the subject in general as well as in particular, under the headings: Combustion process, delay period, turbulence, drop-size, variable delay-time, spontaneous and controlled combustion, chemical characteristics of the fuel and physical properties. Practical methods for oil-engine-fuel knock-ratings are also suggested.
Technical Paper

Commercial Application of Diesel Engines in Heavy-Duty Motorcoaches and Trucks

1932-01-01
320070
COMPARATIVE tests were made, both on the block and in the same motorcoach chassis, of a 525-cu.-in. gasoline and a 495-cu.-in. Diesel engine. The block tests are reported fully in charts, including curves for torque and power against piston displacement and engine weight. Corrected curves are given on the basis of equal piston displacement and for the Diesel engine throttled enough so that it would not smoke. Road tests included fuel consumption, acceleration, hill climbing and top speed, which are also recorded in charts. Other sections of the paper deal with costs of manufacture and maintenance and present and prospective conditions as to supply and cost of Diesel fuel. Stress is laid on the facts that automotive Diesel engines require a much higher grade of fuel than do the larger and slower Diesel units and that more gasoline than fuel oil can be obtained from a given amount of crude.
Technical Paper

Further Investigation of Fuel Injection in an Engine Having Spark Ignition

1932-01-01
320026
THIS INVESTIGATION of fuel injection with spark ignition is a continuation of work previously reported,3 which was carried on in the aeronautic-engine laboratory of the Massachusetts Institute of Technology. Although a four-cycle engine was used, the fuel was injected during the compression stroke so that the results might be applicable to the two-stroke cycle without possibility of loss of fuel through the exhaust. Among the effects studied were those of stratification and of late injection or late ignition as a means of controlling detonation with high compression. Fuels used were aviation gasoline, ordinary Diesel fuel and hydrogenated fuel oil, the last seeming to offer interesting possibilities. Directed turbulence was found to be essential for good distribution of the fuel in the cylinder and satisfactory operation of the engine.
Technical Paper

Ignition Quality of Diesel Fuels as Expressed in Cetene Numbers

1932-01-01
320007
THE paper is an account of some further experiences and views on the subject of ignition in oil engines, which, with the advent of the high-speed Diesel engine, has received much attention of late. The Delft Engine Laboratory of the Royal Dutch Shell Group has been working on oil-engine fuels for nearly four years, with the aid and assistance of all the group's chemical and physical specialists. It had already been working on ignition problems before the high-speed engine was introduced, these problems belonging to a continuous series. Though ignition problems have become of paramount importance in present-day high-speed engines, they have always played a certain rôle with certain fuels also in low-speed engines which were not sufficiently recognized.
Technical Paper

Compression-Ignition Characteristics of Injection-Engine Fuels

1932-01-01
320040
NEEDING to study the ignition characteristics of Diesel-engine fuels, the authors developed an idea that was presented at a meeting of the Research Committee of the Society last June. The idea was that engine tests must be the basis of evaluation. A C. F. R. engine was converted into a variable-compression Diesel engine by substituting a new piston and a fuel-injection system for the original piston and ignition system. Test methods that have been developed are reported, together with some results that show the practicability of the procedure and its substantial agreement with data secured in other ways. It is suggested that, as some of the most desirable qualities of gasoline are undesirable for Diesel fuel, and vice versa, fuels may be divided in the future on that basis, and Diesel and gasoline engines may approach each other in compression ratio.
Technical Paper

SIGNIFICANCE of CETANE NUMBER in FUELS

1946-01-01
460234
CETANE number, a measure of the ingition quality of a fuel, is of importance in the satisfactory operation of a diesel engine; however, there is considerable evidence that cetane number is not the only criterion of a good diesel fuel and that other characteristics indicative of its burning properties must be considered. The authors feel that basic research on diesel fuels is necessary to determine the influence of additives, hydrocarbon structure, and physical properties on ignition and combustion under a wide range of conditions. This work should be so fundamental, they believe, that the results would be applicable not only to diesel engines but also to gas turbines, jet propulsion engines, and rocket engines. ▪ The opinions or assertions in this paper are the private ones of the authors and are not to be construed as official or reflecting the views of the Navy Department or the Naval Service at large.
Technical Paper

COMBUSTION STUDIES of the DIESEL ENGINE

1946-01-01
460218
THE first part of this report on the combustion problems that have been encountered in diesel engines presents the results of experiments conducted on fuels of narrow distillation range and 40 to 90 cetane number. The second part deals with the diesel flame, revealing data on its intensity, temperature, and spectra.
Technical Paper

Effect of Fuel Properties on Diesel - Engine Performance

1946-01-01
460224
THE studies discussed here suggest that the power developed in a diesel is directly proportional to the heating value of the fuel and is independent of its cetane rating, volatility, chemical composition, and molecular structure. Both cetane and volatility, however, the authors say, have marked effects upon cold starting and light-load operation, when the ignition capacity of the cylinder is reduced.
Technical Paper

Influence Of Fuel Composition On Deposit Formation In High-Speed Diesel Engines

1948-01-01
480229
On the background of the wide speed and load variations to which high-speed Diesel engines are subjected, the author diagnoses the temperature conditions under which two different types of unburned fuel deposits may be formed. Solid carbon particles (“soot”) are predominantly the product of incomplete combustion at full throttle or high temperature operation while liquid polymerized fuel fractions are experienced in increasing amounts at the low combustion chamber temperatures synonymous with light loads and reduced speeds. Although some faulty engine conditions may be the cause of excessive soot formation, the author blames most deposits of this nature on the presence of high-boiling or even residual fractions and the poor burning quality of predominantly aromatic fuels. Large differences in the magnitude of low temperature fuel deposits were found by the author without much relation to the commonly used fuel inspection data.
Technical Paper

Effect of DIESEL FUEL on DEPOSITS and WEAR

1948-01-01
480197
SULPHUR content is the most important characteristic of a diesel fuel, as far as engine life is concerned, according to the author, assuming the fuel has a cetane number sufficiently high to provide satisfactory ignition and the purely mechanical problems of cleanliness and flow rate are satisfactorily handled. This is the net result of tests with a 5¾ x 8-in. precombustion-chamber diesel test engine, using the L-1-545 procedure with certain modifications. The fuels used varied in sulfur content from 0.12 to 1.43%, in cetane number from 41 to 61, and in viscosity at 100 F from 36 to 64 SSU.
Technical Paper

Combustion Characteristics of Diesel Fuels as Measured in a Constant-Volume Bomb-A Report of the Coordinating Research Council, Inc.

1952-01-01
520210
A CONSTANT-VOLUME combustion bomb is being employed to give comprehensive data on the ignition characteristics of commercial-type and specially prepared diesel fuels in the investigation reported here. Data presented show the great effect of aromatic and dicyclic compounds in increasing fuel ignition lag and temperature sensitivity. Effects of oxygen concentration and the influence of a diesel fuel additive are shown. The combustion records of some aromatic fuels suggest a 2-stage combustion process and further emphasize that ignition of fuels is not necessarily a threshold phenomenon. Ignition characteristics of fuels are shown for wide ranges of pressures and temperatures. It is indicated that such wide range characterization of any fuel’s ignition properties should be useful in more accurately predicting its combustion behavior under diverse operational conditions.
Technical Paper

Effectiveness of Amyl Nitrate in a Full-Scale Diesel Engine

1952-01-01
520228
THE results of an investigation of amyl nitrate - an ignition accelerator - on the initial combustion characteristics of fuels in full-scale diesel engines are reported here. The use of a good ignition accelerator such as amyl nitrate, the authors say, will benefit refiners, diesel-engine builders, and operators. They report that a wider range of distillate stocks can be used, fuel properties can be controlled more conveniently, and more uniformity of product will be possible. Diesel fuels can also be supplied to meet special requirements such as low noise level and low pour point.
Technical Paper

Procedures Used in Development of Barnes & Reinecke Air Force Diesel Engine

1953-01-01
530253
DEVELOPMENT of a new type of diesel engine for the United States Air Force is described in this paper. Because of the very short time limits, special test stands were built so that development steps usually scheduled consecutively could be carried out simultaneously. This departure required many new approaches to normal testing practices. The author reviews the unusual technical experience derived from this unique program. The development resulted in a diesel engine that met certain primary specifications - it was extremely lightweight, aircooled, and designed for use in any part of the world where jet fuel, aviation gasoline, or diesel fuel is available.
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