Showing papers on "Diesel engine published in 1991"

Using Fiber Optics and Laser Fluorescence for Measuring Thin Oil Films with Application to Engines

Abstract: : A new method has been developed for measuring the oil films on cylinder walls in engines that offers benefits in improved understanding of oil transport and consumption. The unique aspect of this work is that fiber optics and laser induced fluorescence are combined to measure the oil film thickness. As a result the system is much less intrusive than previous methods using windows to observe the fluorescence. Static tests were used to demonstrate the characteristics of the technique. Dynamic tests, performed on a Cameron Plint wear tested, showed the capability of the system to measure thin films under dynamic conditions and at high loads and temperatures. Finally, the system was installed in a diesel engine and used to measure oil film thicknesses under fire conditions. It has been found that oil transport on the cylinder walls of an engine can affect not only oil consumption but emissions. One of the most critical issues that faces the diesel engine industry is the control of particulate emissions. To meet the upcoming emission standards and beyond, advances need to be made in the understanding and control of oil consumption and oil transport.

Exhaust gas purifier for diesel engine

Abstract: An exhaust gas purifier for a diesel engine is positioned in the middle of an inlet system (3) for supplying air to a combustion chamber (2). The exhaust gas purifier comprises an HC (hydrocarbon) supply means (6), and a catalytic converter (18), which is activated by the hydrocarbon as a reduction agent to crack NOx (oxides of nitrogen) in the exhaust gas, thereby purifying the exhaust gas.

Large diesel engine

Abstract: A large diesel engine is provided with a manifold arrangement in which a catalytically coated static mixer is disposed within an exhaust manifold. In addition, nozzles are provided in an annular chamber between the static mixer and the exhaust manifold in order to introduce a reducing agent into the flow of exhaust gas prior to entry into the static mixer. Alternatively, the reducing agent can be injected via a nozzle centrally located in a cover at the end of the manifold.

Diesel Emission Control

Abstract: An overview is given on the kind and origin of tailpipe emissions from diesel engines and on their impact on the environment. The influence of engine type, engine operation condition, fuel composition and test cycle on the composition and properties of diesel engine exhaust are briefly discussed. The present and anticipated emission legislation is summarized. The various approaches to decrease the tailpipe emissions are described. These approaches are grouped in ways to decrease the raw emissions, such as engine design optimization or change of fuel type and properties, and in ways to aftertreat the engine out emissions. The latter involves various types of filtering devices, including catalyzed filters, combinations of filter devices with fuel additives as well as oxidation catalysts. Finally, the ways investigated at present to cope with future requirements, such as a decrease in the nitrogen oxide emission, are presented.

Effects of emulsified fuel on combustion in a four-stroke diesel engine

Abstract: While the use of emulsified fuel in diesel engines has been an area of much research interest in recent years, the promising results reported in laboratories have not been easy to reproduce in commercial practice. Many of these studies have only measured external effects such as fuel consumption and exhaust emissions. A single-cylinder research engine was operated with water/diesel fuel oil and hydrous ethanol/diesel fuel oil emulsions of varying percentages. Crank angle, cylinder pressure and injector lift were recorded electronically over 50 engine cycles, permitting calculation of the mean and standard deviation of key combustion parameters. The results showed decreased fuel consumption and increased ignition delay, peak cylinder pressure and maximum cylinder pressure rise rate for emulsion operation. While the standard deviation data showed little change in cycle-to-cycle variation for water emulsion operation, increases of over 200 percent were measured for operation at ethanol amounts over 20 percent.

Exhaust gas purifying system for internal combustion engine

Abstract: An exhaust gas purifying system including a trap filter for trapping particulates and the like which are discharged from a diesel engine The trap filter in disposed in an exhaust passageway and carries an oxidation catalyst A fuel injector valve is provided to inject fuel into the exhaust passageway upstream of the trap filter, so that the trap filter is supplied with fuel The fuel is burned in the trap filter under the action of the oxidation catalyst thereby burning the particulates and the like so as to achieve a regeneration operation for the trap filter The amount of fuel from the fuel injector valve is controlled to increase as an intake air amount increases and to decrease as an exhaust gas temperature increases

Method for reducing pollution emissions from a diesel engine

Abstract: The invention presented relates to a method for reducing the emission of nitrogen oxides from a diesel engine without significant loss of fuel efficiency and without significant increases in carbon monoxide and hydrocarbon emissions. The method involves preparing a diesel engine such that the injection timing thereof is set at a point sufficient to obtain reductions in the nitrogen oxides emissions from the engine; and firing the diesel engine with a diesel fuel having admixed therein an additive which comprises a fuel soluble organometallic platinum group metal coordination composition.

Exhaust gas purification system for a diesel engine

Abstract: An exhaust gas purification system for a diesel engine (2) with a lean NOx catalyst (4) includes a temperature detecting means (6), an excess air ratio changing means (8) capable of changing an excess air ratio without changing a fuel injection amount, a control means for controlling the excess air ratio changing means (8) so as to increase the excess air ratio when the exhaust gas temperature is higher than an upper limit of a predetermined temperature range and to decrease the excess air ratio when the exhaust gas temperature is lower than a lower limit of a predetermined temperature range. In the exhaust gas purification system, the exhaust gas temperature can be controlled to the temperature range independently of the fuel injection amount.

Removing nitrogen oxides in exhaust gases from a diesel engine

Abstract: The present invention concerns a method of removing nitrogen oxides in exhaust gases from a diesel engine by using a catalyst in a reacter under the presence of ammonia, wherein a humidity of in-take air as a specific factor and one or more of engine power, fuel consumption amount of engine, temperature of engine in-take air and exhaust gas temperature as selective factors are measured respectively as the measuring factors and the flow rate of ammonia is controlled based on measured values and ammonia is supplied to an exhaust gas flow channel from the engine to the reactor.

Apparatus for and method of testing diesel engine heads for fuel and/or collant leaks

Abstract: A method and apparatus for testing an engine cylinder head for leaks regardless of whether the cylinder head is attached to an engine block. The cylinder head has a fuel injector aperture extending from a first side to a second side thereof, has a coolant passageway communicating with the fuel injector apertures between the first and second sides of the cylinder head, and has a sleeve in the fuel injector aperture to separate the fuel injector aperture from the coolant passageway. An air-tight seal is formed in the fuel injector aperture between the coolant passageway and the first side of the cylinder head. Another air-tight seal is formed in the fuel injector aperture between the coolant passageway and the second side of the cylinder head. The fuel injector aperture is then pressurized between the air-tight seals thereof. The pressure of the fuel injector aperture between the air-tight seals is then monitored over a period of time.

Method for the regeneration of particulate-filter systems

Abstract: A method for regeneration of a particulate filter in which the attainment of a stable idling operating condition of the diesel engine is waited for, at least within a specifiable time period after the starting of the diesel engine, rotation-speed signals of the diesel engine being registered in the specifiable time period, before a control device registers and evaluates further operating values and outputs control commands to devices of the particulate-filter system in order to insure reliable burning off of soot particles deposited in the particulate filter and prevent damage to the particulate filter due to incorrect control actions.

Air purging and shut-down system for diesel engines

Abstract: A fuel system for a diesel engine includes an air purging system for venting trapped air to a vent line connected to a fuel tank and an emergency shut-down system for providing a fail-safe shut-down of the engine when fuel is low. The air-purging system comprises a device defining a float chamber having an air outlet communicating with the vent line, a fuel inlet, and a fuel outlet. A float is disposed in the chamber and is adapted to move between a normal first position closing the air outlet, an emergency intermediate second position opening both the air and fuel outlets, and a shut-down third position opening the air outlet and closing the fuel outlet. The emergency shut-down system includes electronic and pressure sensitive switches, warning lights, and an auxiliary fuel pump to monitor and control the shut-down and restart modes of engine operation. The air purging system is adapted to function independently of the emergency shut-down system.

Exhaust gas reflux device of diesel engine

Abstract: PURPOSE:To obtain the optimum EGR gas reflux pressure for decreasing a quantity of NOx by providing a soot trap and a gas cooler, and also providing an exhaust pressure control valve on the way of an EGR gas reflux circuit which forces exhaust gas downstream of an exhaust turbine supercharger to flow back to the intake side. CONSTITUTION:The inlet part of an EGR gas pipe 13 which constitutes an EGR gas reflux circuit 12 is connected to the middle of an exhaust pipe 6, in a diesel engine equipped with an exhaust turbine supercharger 4, and the outlet side of the EGR gas pipe 13 is connected to the middle of an intake pipe 2 via a soot trap 14 and an EGR gas cooler 21 on the way thereof. Consequently, the exhaust gas in the exhaust gas pipe 6 is forced to flow back to an intake pipe 8 in front of a blower 7 as the EGR gas. A variable exhaust pressure control valve 15 which can vary continuously a quantity of the exhaust gas which flows through the exhaust pipe 6, is provided on the way of the exhaust pipe 6 located downstream from the connection part of the EGR pipe 13, and the exhaust gas pressure forced to flow back to the EGR gas pipe 13 is controlled by adjusting the valve 15.

Diesel engine exhaust gas-purifying catalyst

Abstract: There is provided a Diesel engine exhaust gas-purifying catalyst which comprises (1) a catalytic component comprising titania having dispersed and deposited thereon at least one noble metal selected from palladium, platinum and rhodium, and (2) a refractory three dimensional structure as a carrier. This catalyst is excellent in the performance of removal by combustion at low temperature of harmful components such as uncalcined hydrocarbons and carbon monoxide in addition to carbonic fine particles, and moreover has only low ability to oxide sulfur dioxide, whereby formation of sulfates can be inhibited.

Method and apparatus for supply of decontaminated fuel to diesel engine

Abstract: Apparatus for the supply of decontaminated fuel to a diesel engine including two filtering stages, the first being a spiral wound, cross flow ultrafiltration unit and the second being a spiral wound deadheaded ultrafiltration unit with a pressure operated alarm connected to respond to the build-up of contaminants in said second stage.

Combustion chamber of direct injection type diesel engine

Abstract: PURPOSE: To remarkably decrease smoke and NOx at the same time by only varying the structure of a combustion chamber. CONSTITUTION: The combustion chamber of a direct injection type diesel engine is provided with a fuel injection valve 6 arranged in a cylinder head 5, a plural number of injection ports formed at the nozzle 7 of the fuel injection valve 6, an outer circumferential flat part 1a formed on the top face of a piston 1, a combustion chamber 9 formed inside the outer circumferential flat part 1a, a groove part 10 formed along the fuel injection direction from the injection port of the nozzle 7 on the bottom face 1b of the combustion chamber 9, and penetrating port 12 which communicates the groove part 10 with the outer circumferential flat part 1a of the piston 1. COPYRIGHT: (C)1993,JPO&Japio

Nox removing device

Abstract: PURPOSE:To decompose NOx with reduction catalyst without the need of ammonia by adsorbing NOx in the exhaust gas of engine, desorbing it with the combustion gas of low O2 concn., and passing it through the reduction catalyst to decompose NOx into N2 and O2. CONSTITUTION:There are provided the NOx adsorption unit 4 in which zeolite, etc., is used as an adsorbent, a high temp. gas generation unit 7, and a reduction unit 5 provided with the reduction catalyst. NOx in combustion gas is adsorbed in the NOx adsorption unit 4, and then desorbed by the high temp. gas of low O2 concn. sent from the high temp. gas generation unit 7, and the desorbed NOx is decomposed by the reduction unit 5 into N2 and O2. As a result, the NOx in the exhaust gas of engine, especially of diesel engine, is removed. The device of this system is allowed to be miniaturized because reduction gas, such as ammonia, is not used.