Showing papers on "Carbureted compression ignition model engine published in 1986"

Dual fuel compression ignition engine

Abstract: A dual fuel compression ignition engine (10) comprises a gas fuel supply system (20-25) for the engine (10), and a diesel fuel supply system (12-16) for the engine, including an injection pump (11) having a governor and a control member to control the amount of diesel fuel injected into the engine by the pump (11), and means (13') to arrest movement of the control member (11a) in the direction to increase the supply of diesel fuel to the engine, at a position to supply pilot fuel at a constant, or substantially constant, rate, the position for arrest being determined in accordance with at least one operating condition of the engine, such as the engine speed. Another embodiment shows a present rail system. In both, the amount of pilot diesel fuel is adjusted by a feed-back signal indicative of the amount of pilot fuel injected.

Combustion Exhaust Emissions of the Spark-Assisted Methanol Diesel Engine

Abstract: Ignition and combustion of methanol in a spark-assisted methanol diesel engine were studied for the purpose of developing such an engine that is practical for actual vehicles. It became clear through investigations on combustion of methanol in a spark-assisted methanol diesel engine that methanol combustion proceeds mainly by flame propagation. Based on this finding, effects of such parameters as the injection direction, ignition position, ignition energy, compression ratio, injection timing and ignition timing were studied to obtain optimal conditions for methanol combustion. It was found through such studies that it is effective to form the mixture upstream of the spark plug relative to the swirling direction and increase the inductive component of the ignition energy to achieve a high ignition stability. It was also found that it is effective for raising the engine performance and improving exhaust emission characteristics to form the mixture downstream of the spark plug relative to the swirling direction so that the flame propagates along the swirl and to position the spark plug closer to the wall of combustion chamber so that the combustion is accelerated by the thermal mixing effect. The spark-assisted methanol diesel engine thus developed was mounted to a vehicle. The vehicle demonstratedmore » superior fuel economy with very low levels of exhaust emissions.« less

A photographic study of the combustion of low cetane fuels in a Diesel engine aided with spark assist

Abstract: An experimental investigation of the ignition and combustion characteristics of two low cetane fuels in a spark assisted Diesel engine is described. A three cylinder Diesel engine was modified for single cylinder operation and fitted with a spark plug located in the periphery of the spray plume. Optical observations of ignition and combustion were obtained with high speed photography. Optical access was provided by a quartz piston crown and extended head arrangement. The low cetane fuels, a light end, low viscosity fuel and a heavy end, high viscosity fuel which were blended to bracket No. 2 Diesel fuel on the distillation curve, demonstrated extended operation in the modified Diesel engine. Qualitative and quantitative experimental observations of ignition delay, pressure rise, heat release, spray penetration and geometery were compared and evaluated against theoretical predictions. Results indicate that controlled combustion of extended fuel blends in a Diesel engine may be possible without inlet air preconditioning and that engine knock may be avoided when heat release is optimized with proper spark and injection timing.

The Autoignition and Combustion of Coal-Water Slurry Under Simulated Diesel Engine Conditions

Abstract: The combustion characteristics of a coal-water slurry spray were examined under diesel engine conditions. A two-stage combustion process was used to simulate the diesel engine conditions in a constant-volume combustion bomb. The combustion characteristics investigated were ignition delay, ignition site, combustion development, combustion duration, and combustion completeness. The results show that the ignition delay of the coal-water slurry fuel is temperature and pressure dependent. Also, the coal slurry ignition delay is approximately a factor of five longer and the energy release rate is significantly slower in comparison to the ignition delay and energy release rate for conventional No. 2 diesel fuel.

Method and system for controlling fuel ignition timing in diesel engine

Abstract: In determining an optimum target fuel ignition timing in accordance with the engine operating conditions, including at least an engine load and an engine speed, the target ignition timing is determined on the basis of a corrected engine load and a corrected engine speed. The corrected engine load and corrected engine speed are obtained by making corrections, according to the engine operating conditions, to a detected engine load and a detected engine speed, respectively. In this way, the optimum target fuel ignition timing according to the engine operating conditions can be obtained without directly detecting a fuel injection quantity.

An Investigation of Puff-Jet Ignition in an Internal Combustion Engine Fueled by Natural Gas

Abstract: Etude d'un nouveau mode d'allumage pour moteurs a combustion interne utilisant du gaz naturel, comme carburant (admission d'une petite quantite de gaz par une soupape rapide)

Puff-Jet Ignition of Methane in an Internal Combustion Engine

Abstract: The puff-jet, a mechanically assisted ignition system, produces a turbulent ignition kernel that enhances the combustion of methane, a slow burning fuel. Detailed mapping of the puff-jet ignition system in a motored internal combustion engine has confirmed preliminary results. Compared with a spark gap ignition system, the puff-jet decreased both the ignition delay and the burn duration of methane charges in a motored single cylinder internal combustion engine and extended the lean misfire limit. Output power from the same engine run continuously on lean air-methane mixtures was increased using the puff-jet system because of the ameliorated combustion characteristics using that ignition system rather than a conventional igniter. Further, the output power from the engine running continuously with the puff-jet was almost the same as that achieved with a plasma jet igniter, without the concomitant high energy demand or electrode wear

Device for the preheating of diesel fuel for a motor vehicle with diesel engine

Abstract: For the preheating of diesel fuel the fuel line is led through an area heated by the engine.

Synthetic Fuel Operation in a Heavy Duty Diesel Engine

Abstract: A heavy duty (150 kW) diesel engine was tested to determine operational problems while running on minimally processed synthetic fuels. A reference No. 2 diesel fuel was compared with liquid products derived from shale, tar sands and coal. Information on the engine setup and test procedure is presented. The test results include engine power, thermal efficiency, ignition delay, gaseous and particulate emissions, smoke opacity, cylinder pressure, and heat release data. Cold start data at 0/sup 0/C and -20/sup 0/C and idle deposit test results are also presented. These data should help to determine future engine modifications to enhance synfuel engine performance.

Testing of a Mixture Preparation System for Spark Ignition Internal Combustion Engines

Abstract: An experimental investigation of the performance of a mixture preparation system used with spark ignition internal combustion engines is presented. The proposed carburetor works on the principle of adiabatic vaporization of liquid gasoline fuel before it is led to engine cylinders by means of passing atmospheric air, induced by engine suction, through fuel. The study aims at the determination of parameters that affect the performance of this system. It is demonstrated through the results that this carburetor is a better device for mixture preparation in spark ignition engines having numerous advantages over conventional carburetors most notably fuel economy.

Theoretical studies on the combustion of hydrogen, alcohol and isooctane fuels in divided chamber spark ignition engine

Abstract: A mathematical model of the compression, combustion, and expansion phases of the divided chamber spark ignition engine is reported here. This model has been developed in an attempt to combine as many as possible of the basic characteristics of the divided chamber spark ignition engine combustion. It is used to compare the predicting performance and emission levels when operating the engine with hydrogen, alcohol and isooctane fuels. A procedure for incorporating simple kinetic mechanisms for NO formation and CO oxidation are built into the model. The divided chamber engine is treated as a pair of two thermodynamic sub-systems (prechamber and mainchamber systems) coupled by mutual mass flow. The results obtained are related to such important practical questions, as the affect of prechamber volume ratio, connecting orifice size, fuel type and degree of charge stratification, on predicting performance and emission levels. This study shows that, the divided chamber engine performance and emission levels are strongly affected by these design parameters. The results also indicated that improvement in engine performance and emission levels have been fulfilled when using hydrogen and alcohol fuels than that with isooctane. Moreover, two stage combustion results in a loss of power compared to conventional spark ignition engine. This may be more than compensated in practice. The reasons for this power loss and possible means of compensation are discussed here.

Experiment on Combustion of High Viscosity Fuels by Medium Speed Diesel Engines

Abstract: Since the oil crises of late about 10 years, the diesel engine fuel tends to be higher in viscosity and lower in quality. As for“high viscosity”and“low quality”, it is learned from many studies that these two words are not always the same meaning. In fact, the influences on the diesel engine performance or on the durability of the engine components are different according to the fuels from different refinery process or crude oil sources even with the same viscosity level. In actual fuel market, however, fuel is classified mainly by the viscosity and the viscosity grade is the first way for the users and the engine manufacturers to discriminate fuel. Therefore it is interesting to know the influence of reference viscosity of the fuel on the diesel engine performance.From these points of view, a series of experiments has been carried out on a medium speed diesel engine using high viscosity fuels from 380 cSt up to 1000 cSt (@50°C) prepared by blending the same base oil and cutter oil. Marine diesel oil has also been tested in order to compare with the high viscosity fuels.This paper describes the results of above-mentioned experiments; i.e. combustion characteristics especially on the ignition delay and on the combustion duration as well as the injection characteristics. The problems at low load region such as smoke and deposit formation on the combustion chamber are also discussed in connection with the combustion characteristics.

Turbine combustion engine

Abstract: The construction is designed for greater power, higher speed for a lower displacement due to a long lever arm from the ignition force to the axle, the lower compression evening out the engine power output in a much more favourable way. The engine is intended to be used where less heed has to be paid to braking effect. Not only unleaded petrol, but also kerosene, which is cheaper and more ignitable, is intended as fuel for the above-mentioned engine, since the ignition force acts in the direction of rotation of the flywheel (without reverse movement).

Optimization of a cfr diesel engine and combustion of heavy fuels

Abstract: The aims of the project described in this article were to: (1) measure the ignition and combustion properties of various residual fuels in a diesel engine; (2) correlate the engine performance with fuel characteristics; and (3) test possible effects of combustion improvers.

Method for the heating of diesel fuel and device for performing the method

Abstract: A method for the preheating of diesel fuel is specified. In this, the diesel fuel is passed through the engine oil so that the temperature of the engine oil preheats the diesel fuel. To perform the method either a coiled pipe (24) or a tank (32), around both of which engine oil flows on all sides, can be fitted in the oil sump (14).

Ignition circuit for internal combustion engines

Abstract: An ignition circuit for internal combustion engines includes a resonant oscillation circuit (4) comprising a capacitor (3) in parallel with a coil (2a) of a sensor core (2b) The core is disposed adjacent an engine driven rotary metallic member (1) having a plurality of projections (1a-1d) spaced around its periphery and equal to the number of engine cylinders The circuit resonates unless a projection lies opposite the core to suppress oscillations by eddy current loss The oscillation signal amplitude is monitored by a threshold detector (5) whose switching output controls the supply of power to an ignition coil (10) This minimizes the ignition timing lag increase as a function of engine speed, and attendantly any engine power loss

Investigation on increasing compression ratio to improve thermal efficiency of hydrogen-gasoline dual engines

Abstract: During addition of a small amount of hydrogen into the gasoline-air mixture, the ignition limit of the gasoline will be extented, the velocity of the flame propagation will be increased, thus the rapid combustion of the lean mixtures can be realized, therefore, increase thermal efficiency and decrease pollutions as well as improve detonation tendency of the gasoline engine. By burning gasoline-hydrogen mixed fuel to increase the compression ratio could rise futher the thermal efficiency. On account of detonation phenomena appear easier in the L-type combustion chamber, we chose a side-valre engine as our testing engine. This paper discusses the possibility to increase compression ratio and describes in detail the experimental results on the mixed fuel combustion with compression ratio 6.0 and compression ratio 6.49 respectively.

The Development of New Procedures for Rating the Ignition Quality of Fuels for Diesel Engines.

Abstract: : The ignition delay times of 42 different fuels were measured in a constant voulume combustion bomb. The measurements were performed at three different initial air temperatures using fuels ranging from the primary reference fuels for cetane rating to complex mixtures of coal-derived liquids. A single-cylinder, variable compression-ratio, direct-injection diesel engine was designed and constructed to study the ignition quality of 17 of the 42 fuels. The total ignition delay times in the bomb were studied in the context of providing a means for rating the ignition quality of the fuels. Fuel ignition quality rating schemes are discussed, including one based on the current cetane number scale as well as one based on a new scale which includes a measure of the sensitivity of the various fuels to the air temperature. The ignition delay times in the engine have been measured as functions of the engine speed, load, and compression rato. Keywords: Centane, Variable, Compression, Ratio combustion, Bomb, Fuels, Ignition.

Biomass fuels in internal combustion engines

Abstract: This chapter describes the biomass fuels in internal combustion engines. In most respects, ethanol and methanol are fairly similar to gasoline and, therefore, they are more suitable for engines working with spark ignition than with compression ignition. The necessary modifications to a spark ignition engine depend on whether the engine will operate on straight alcohol, or on a blend of alcohol and gasoline. For blended fuels with less than 5% methanol or 10% ethanol, no modifications to an engine designed for gasoline are normally required and the power and the efficiency of the engine will not be affected. With 15% methanol or 25% ethanol, minor parts in the fuel system may have to be changed because alcohols are more aggressive to some polymers and metals, which may have to be changed. For operation on straight alcohol fuel, the minimum modification necessary to operate the engine is to adjust or replace the carburetor nozzle to allow double fuel flow. To simplify cold starts, it is also advisable to maintain the possibility for operation on gasoline.