Showing papers on "Diesel engine published in 1989"

Variable-discharge high pressure pump

Abstract: A variable-discharge high pressure pump (10) for pressure-feeding fuel to a common rail (6) for use in a diesel engine (1). The pump has a plunger (18), a plunger chamber (19), a cam (17) for reciprocatively moving the plunger; an opening-out type electromagnetic valve (15) capable of opening and closing one end of the plunger chamber, a fuel reservoir (22), a check valve (23) communicating with the plunger chamber, and an inlet pipe (14) for supplying fuel to the fuel reservoir. Both the introduction of the fuel into the plunger chamber and the return of the fuel from the plunger chamber to the fuel reservoir are effected through the electromagnetic valve.

Simplified Three-Dimensional Modeling of Mixture Formation and Combustion in a D.I. Diesel Engine

Abstract: This paper describes a simplified three-dimensional modeling of the mixture formation and combustion processes in a direct injection (D.I.) diesel engine. The fuel-air mixing and combustion processes in the D.I. diesel engine can be characterized by the combined effects of some processes, such as spray trajectory, fuel vaporization, gas motion, combustion, and dispersion of gaseous components and enthalpy. Each process was computed by a simple sub-model based on the experimental results and empirical equations. Reasonable agreement between computed and experimental results for these engine variables demonstrate that, with appropriate adjustments to the empirical coefficients of each model, the model produces qualitatively realistic predictions of the in-cylinder processes and engine performance. (A) For the covering abstract see IRRD 865952.

Characteristics of a diesel spray impinging on a flat wall

Abstract: In a small high-speed DI diesel engine, injected fuel sprays impinge on the wall of the piston cavity. Discussion and analysis of the combustion phenomena in the diesel engine demand the measurement of the characteristics of the impinging spray. In the experiments presented here, diesel fuel oil was injected into a high pressure chamber in which compressed air or CO2 gas at room temperature was charged. From these results, the detailed information concerning the droplets density in the impinging diesel spray was obtained. The effects of ambient density, distance from the wall to the nozzle, and injection pressure on the impinging spray were analyzed. Finally, the experimental equations of the radius and the height of the impinging spray were proposed as functions of the above mentioned variables. (A) For the covering abstract see IRRD 865952.

Spray characteristics and combustion improvement of D.I. diesel engine with high pressure fuel injection

Abstract: The paper discusses a high pressure injection equipment (HPIE), which is an electronically controlled, hydraulic pressure-intensified system that can produce 250MPa, that has been developed This equipment has been evaluated with shadow photographs for analyzing non-evaporating fuel spray characteristics It was found that the fuel injected at high pressure forms a finer and more homogeneous spray When the HPIE was fitted to a naturally aspirated 2 liter single-cylinder diesel engine and tested, it was found that black smoke and particulate emissions decreased, under suitable injection timing for low NOx emission The emission test data at 220MPa of injection pressure shows that more than 80% reduction of particulate emission has been realized at the same NOx level These results indicate that the high pressure fuel injection is an effective means for reducing NOx, smoke and particulate emissions For the covering abstract see IRRD 865952

The effect of insulated combustion chamber surfaces on direct-injected diesel engine performance, emissions, and combustion

Abstract: The combustion chamber of a single-cylinder, direct-injected diesel engine was insulated with ceramic coatings to determine the effect of low heat rejection (LHR) operation on engine performance, emissions, and combustion. In comparison to the baseline cooled engine, the LHR engine had lower thermal efficiency, with higher smoke, particulate, and full load carbon monoxide, emissions. The unburned hydrocarbon emission were reduced across the load range. The nitrous oxide emissions increased at some part-load conditions and were reduced slightly at full loads. The poor LHR engine performance was attributed to degraded combustion characterized by less premixed burning, lower heat release rates, and longer combustion duration compared to the baseline cooled engine. 33 refs., 67 figs., 7 tabs.

Investigation of the effects of fuel composition on heavy-duty diesel engine emissions

Abstract: Models for transient composite emissions were obtained using multiple linear regression techniques, and changes to regulated emissions for selected changes in fuel properties were estimated from the models. Decreasing fuel aromatic content, sulfur, and volatility (increasing 90 percent boiling point temperature) were generally associated with reductions to regulated emissions

Diesel engine exhaust oxidizer

Abstract: A device for connection to a diesel engine to collect soot and other particulate emissions before the exhaust is discharged to atmosphere. When the filter (24) becomes loaded with particulates to the point where it either may not function properly or otherwise interferes with the vehicle's operation, a forced regeneration cycle is induced. During forced regeneration a valve mechanism (28) at the inlet (20) to the device is operated to divert flow from the main flow path (22) into a bypass passage (26), and an electric power heater (54) is energized elevating the temperature of the filter (24) to burn off the accumulated particulate material. The valve mechanism (28) is duty cycled as the forced regeneration process continues. As the process concludes, the valve open time increases and this increase is monitored to terminate the duty cycle operation so that the main passage through the device is now open. The main passage through the device contains a series of nested vanes (46a,b,c,d,e,f,g,h,i,j) which take the axial flow of particulate-containing exhaust and direct it outwardly through the filter (24) which is located just after the vanes. In certain embodiments an electrostatic precipitator precedes the filter to enhance soot collection efficiency.

Proportional hazards analysis of diesel engine failure data

Abstract: Canadian Pacific Rail's diesel engines undergo scheduled major overhaul at intervals of approximately four years. Between these overhauls the condition of an engine is monitored by a series of physical tests and spectroanalysis carried out on samples of lubricating oil. At present the results of these tests are interpreted by the combination of skilled oil-analyst technicians and an expert system. The success rate of this is over 70 per cent, where success is defined to mean that the oil-analyst/expert system recommends that the engine should be scheduled for maintenance and it does indeed subsequently show evidence of an imminent failure. The purpose of the paper is to report on an examination of the method of proportional hazards modelling to determine whether or not PHM could improve on the accuracy of the oil-analyst/expert system in determining the risk of failure of a diesel engine.

Cycle-Resolved LDV Measurements In a Motored Diesel Engine and Comparison with K-ε Model Predictions

Abstract: Cycle-resolved LDV measurements of tangential mean velocities and turbulence intensities were made in a motored, single cylinder, Cummins NH diesel engine at 300 and 600 rpm. The measurements were made at eight locations in a plane 0.9 cm below the cylinder head. The combustion chamber and intake configuration of this low-swirl, low-squish engine were nearly identical to the stock configuration. For improved optical access, however, the compression ratio was lower in the test engine (10:1) than in the production engine (14.5:1). The measured turbulence intensities were compared to values computed with KIVA, an in-cylinder fluid dynamics flow code with a {kappa}-{epsilon} turbulence model. The measurements show that the mean velocity field is three-dimensional before TDC, consisting of both a weak swirling motion and a weak tumbling motion.

Ceramic foam prefilter for diesel exhaust filter system

Abstract: A filter device for trapping particulates for diesel engine exhaust gases including an electrical heating element for regenerating the primary monolithic ceramic filter and a porous cermaic disc pre-filter between the heating element and the primary filter to provide a practical secondary source of heat when particulates on it combust during regeneration.

Engine emissions control apparatus and method

Abstract: Apparatus and method for reducing the emissions of a diesel engine. A hydrous alcohol fuel of low proof supplements the diesel fuel, particularly in high acceleration and high r.p.m. conditions. The fuel is fumigated into the airstream of the intake manifold of the engine by a fuel injector that is supplied both the alcohol fuel and air under pressure. Control apparatus begins delivery of the alcohol fuel above a selected engine r.p.m. and the amount delivered generally corresponds to engine r.p.m. Under heavy acceleration, the flow of diesel fuel is reduced and engine power is brought back up by the alcohol fuel. No alcohol fuel is used when the engine is decelerating or reducing its r.p.m.'s.

W/O emulsion realizes low smoke and efficient operation of DI engines without high pressure injection

Abstract: This paper describes an experiment in which water-in-gas oil emulsified fuel is used without high pressure or high injection rate to improve engine performance parameters such as smoke, NO/sub chi/, and BSFC in a DI diesel engine. The results are compared with high pressure and high injection rate operation using gas oil.

Particulate filter system

Abstract: Method and apparatus for regenerating a particulate filter of a diesel engine. Disclosed is a particulate filter that, at all operating points of the diesel engine, can be regenerated by means of a burner working in the main engine exhaust stream. Regeneration is achieved by means of a burner (3) to which fuel and oxygen-containing gas is supplied in a variable proportion. By this means, the burner can produce the output required to achieve the regeneration temperature at any operating point of the diesel engine. The apparatus is suitable for diesel engines having thermally regenerable particulate filters.

A Comparision of the Performance of Two Direct Injection Diesel Engines From a Second Law Perspective

Abstract: This work reviews the differences in fuel economy between two direct injection diesel engine versions through the use of a First Law energy balance and a Second Law availability balance. Both experimental data and simulated results are used in the analysis. The use of an engine simulation allowed the important processes in each engine to be analyzed and a Second Law effectiveness calculated. The availability balances and effectiveness values are used to determine the effect of major engine components on the fuel economy. A comparison is also made with an ideal engine with selected perfect or reversible processes.

Combustion Phenomena of Alcohols in C. I. Engines

Abstract: A study was conducted on a direct-injection, single-cylinder, research-type diesel engine to determine the effect of adding ethanol or isopropanol to diesel fuel on the ignition delay period. The test parameters were alcohol content, intake-air properties, and fuel-air ratio. It was found that the ignition delay of alcohol-diesel blends is prolonged as the alcohol content is increased. Ethanol-diesel blends developed longer ignition delays than those developed by isopropanol-diesel blends. The results showed that ignition delay of alcohol-diesel blends can be effectively shortened using intake-air preheating and/or supercharging. The high activation energy of alcohols with respect to diesel fuel is believed to be responsible for the long ignition delays associated with the use of alcohols as alternate fuels in compression ignition engines.

A Chronic Inhalation Toxicity Study of Diesel Engine Emissions and Coal Dust, Alone and Combined:

Abstract: To evaluate the potential health hazards of diesel engine emissions in underground coal mines, inhalation studies were performed using three species of animals. A wide range of toxicological responses was measured. Exhaust was provided by a 425 in.3 displacement four-cycle, water-cooled, naturally aspirated diesel engine (Caterpillar Model 3304) equipped with a water scrubber. Exposures were 7 h/day, 5 days/week, for periods up to 24 months. Micronized coal dust was generated using a Wright dust feeder. Four exposures were evaluated: (1) filtered ambient air, (2) 2 mg/m3 diesel particulate, (3) 2 mg/m3 respirable coal dust, and (4) 1 mg/m3 each of 2 and 3. Gaseous and vapor concentrations were similar in both exposures employing diesel exhaust. Male cynomolgus monkeys, Fischer-344 male and female rats, and female CD-1 mice were the experimental subjects. Monkeys were sacrificed at 24 months, rats at 3, 6, 12, and 24 months, and mice at 1, 3, and 6 months.Gross morphology and histopathology demonstrated th...

Charge air fuel cooler

Abstract: In combination with a diesel engine, an engine air intake conduit leading preferably to a turbocharger, a source of fuel, and a circuitous fuel path supplying fuel to the engine from the source and returning uncombusted fuel from the engine to the source, is a fuel cooler. The fuel cooler is mounted within the engine air intake conduit upstream of the turbocharger, if present, in a manner allowing intake air to flow through a central passageway of the cooler to the turbocharger. The fuel cooler is further engaged within the circuitous fuel path in a manner allowing heated fuel to travel through a peripheral passageway formed in the fuel cooler. The peripheral passageway is contiguous to the central passageway whereby heat from the heated fuel is transferred to the intake air, thus cooling the fuel. The fuel cooler is used preferably in cooling uncombusted diesel fuel being returned toward the storage tanks of a vehicle from the engine. The fuel cooler comprises an elongate cylindrical body including an integrally molded heat exchanger therein. The heat exchanger has a continuous, convoluted inner wall defining a central passageway therewithin which extends longitudinally through the elongate cylindrical body. The elongate cylindrical body also has a tightly spiralled peripheral passageway cored therein, an inner surface of which forms an outer wall of the heat exchanger. The elongate cylindrical body also has two ports therein, each positioned toward an opposite end of the cylindrical body and opening into and communicating with the cored peripheral passageway.

The Influence of High Pressure Fuel injection on Performance and Exhaust Emissions of a High Speed Direct injection Diesel Engine

Abstract: Conventional direct injection diesel engines for cars or light duty trucks, equipped with injection pumps of conventional types, such as distributor injection pumps and inline injection pumps, and operating at compression ratios of 18-19, are capable of offering a fuel consumption benefit of some 15% compared to chamber diesel engines. In terms of noise and exhaust emissions, and also black smoke characteristics they are significantly inferior to the prechamber engine. They have a specific rated output which is some 20% lower. Only through the use of a compression ratio of 21 and high injection pressures it is possible to measurably diminish the drawbacks in respect of exhaust emissions and, to some extent, in respect of soot emissions. This in no way enhances the noise behaviour. For this reason, it is essential to employ measures such as injection rate shaping or split-injection. Satisfactory engine characteristics are best achieved if a pilot- injection is used. Such a pilo- injection is only feasible with an electronically controlled unit injector.

Rotating diesel particulate trap

Abstract: A rotating particulate trap is disclosed, which may find application in diesel engines, air conditioning systems, industrial air-filters and the like. The invention includes a disk or cylinder which is formed from material suitable for filtering particulates which are present in the exhaust gases of diesel engines, gas turbines, industrial air or other particulate laden gases. The disk is mounted transversely in the exhaust duct of a diesel engine and in a fresh air duct which is disposed parallel to the exhaust duct. As the disk rotates within the exhaust duct, it filters particulates from the exhaust gases of the diesel engine. The filtered particulates are expelled from the disk by fresh air blowing in the air duct as the disk rotates within the air duct. The fresh air is blown in the air duct in a direction opposite to the flow of exhaust gases within the exhaust duct by a fan or compressor or compressed air jets. The counterflow arrangement of fresh air and combustion gases enhances the effectiveness of particulate removal as the disk rotates between the exhaust duct and the fresh air duct. Particulates expelled from the disk are blown into a filter bag which is attached to the end of the fresh air duct.

Direct injection-type diesel engines

Abstract: A direct injection-type diesel engine includes a piston head (5) formed with a novel piston combustion chamber (6), with an inner wall surface composed essentially of ceramic material having a low thermal conductivity. The combustion chamber has a reduced opening diameter (d) of not more than 55% of the bore diameter to enhance a squish air flow out of the clearance space between the piston and the cylinder head, and has a maximum diameter (x) of not less than 128% of the opening diameter (d). This construction allows significant reduction of smoke, unburnt hydro­carbon and particulates in the exhaust gas, as well as minimization of thermal loss of the engine.

Engine lubricating oil for diesel engines and process for operating a diesel engine

Abstract: To avoid an unacceptably high exhaust gas back pressure when operating diesel engines equipped with a particle filter in the exhaust gas stream, an engine lubricating oil is used that has a catalytically active content of an iron compound in an amount of 5 to 20,000 ppm. The use of the additive facilitates the regeneration of the diesel particle filters by burning, especially under operating conditions of the diesel engine that lead only to relatively low exhaust gas temperatures. Iron compounds proposed are ferrocene, ferrocene derivatives, and iron salts of organic acids.

Automatic air bleeding device for fuel feed system of diesel engine

Abstract: A check valve is disposed in a suction-side line of a feed pump in a fuel feed system and permits the fuel to direct only toward a feed pump; a bypass line is provided for bypassing the check valve; and a pump is disposed in the bypass line. Alternatively, a line is branched from the suction side line of the feed pump in the fuel feed system and is communicated with a gallery chamber within the feed pump; a check valve is disposed in the branched line to direct the fuel only flowing toward the gallery chamber line; and a pump is disposed in the branched line upstream of the check valve. As a result, when air intermixes in the fuel feed system, the pump is energized prior to starting the engine to force the fuel having the air bubbles entrained therein though the feed pump into a fuel tank, thereby accomplishing air bleeding operation.

Jet Kerosene Fuels for Military Diesel Application

Abstract: The United States Department of Defense has proposed the use of one fuel for combat, JP-8, in ground vehicles and equipment as well as in aircraft. To support this proposal, the Defense Fuel Supply Center requested that samples of JP-8, JP-5, and Jet A-1 from worldwide sources representing tenders of products destined for DOD bases be evaluated. Properties affecting diesel engine operation, i.e., cetane number, calculated cetane indices, kinematic viscosities at 40 o and 70 o C, and net heat of combustion were evaluated and compared to the requirements of Federal Specification VV-F-800D and NATO F-54. Several inspection tests were also conducted, and the data were compared to that information supplied by the refiners. Frequency histograms and other statistics for many properties are presented