Showing papers on "Carbureted compression ignition model engine published in 2002"

High Efficiency and Low Emissions from a Port-Injected Engine with Neat Alcohol Fuels

Abstract: Ongoing work with methanol- and ethanol-fueled engines at the EPA’s National Vehicle and Fuel Emissions Laboratory has demonstrated improved brake thermal efficiencies over the baseline diesel engine and low steady state NOx, HC and CO, along with inherently low PM emissions. In addition, the engine is expected to have significant system cost advantages compared with a similar diesel, mainly by virtue of its low-pressure port fuel injection (PFI) system. While recognizing the considerable challenge associated with cold start, the alcohol-fueled engine nonetheless offers the advantages of being a more efficient, cleaner alternative to gasoline and diesel engines. The unique EPA engine used for this work is a turbocharged, PFI spark-ignited 1.9L, 4-cylinder engine with 19.5:1 compression ratio. The engine operates unthrottled using stoichiometric fueling from full power to near idle conditions, using exhaust gas recirculation (EGR) and intake manifold pressure to modulate engine load. As a result, the engine, operating on methanol fuel, demonstrates better than 40% brake thermal efficiency from 6.5 to 15 bar BMEP at speeds ranging from 1200 to 3500 rpm, while achieving low steady state emissions using conventional aftertreatment strategies. Similar emissions levels were realized with ethanol fuel, but with slightly higher BSFC due to reduced spark authority at this compression ratio. These characteristics make the engine attractive for hybrid vehicle applications, for which it was initially developed, yet the significant expansion of the high-efficiency islands suggest that it may have broader appeal to conventional powertrain systems. With further refinement, this clean, more efficient and less expensive alternative to today’s petroleum-based IC engines should be considered as a bridging technology to the possible future of hydrogen as a transportation fuel.

The Effects of Diesel-Ethanol Blends on Diesel Engine Performance

Abstract: The performance of a variable compression ratio compression ignition engine operating on ethanol-diesel fuel blends has been evaluated experimentally. We aimed to determine the optimum percentage of ethanol and the compression ratio of the engine that give the best performance and efficiency at the same time. The engine was operated with ethanol-diesel fuel blends having 2, 4, and 6% ethanol on a volume basis as well as on diesel fuel alone. The experiments were performed for the compression ratios of 19, 21, and 23. Experimental results indicate that the addition of 4% ethanol to diesel fuel increases power output and efficiency of the engine while it decreases specific fuel consumption for various compression ratios. The best efficiency was attained at the compression ratio of 21 with an increment ratio over 3.5%.

The effect of a waste vegetable oil blend with diesel fuel on engine performance

Abstract: Vegetable oil fuels can be considered a renewable energy resource. Waste vegetable oil–diesel fuel blends can recycle used frying oil, which is essentially a waste product. The objective of this work was to determine the feasibility of running a 10% waste vegetable oil–90% diesel fuel blend during a 500–h period in a 3–cylinder direct–injection, 2500 cm 3 Diter diesel engine. Periodically, several tests were carried out to evaluate the performance and implications of such an approach. The long–term performance of this fuel was monitored by measuring the viscosity of the lubricating oil, abnormal functioning of the engine, power loss, and excessive smoke output compared to straight diesel fuel. The results revealed an approximately 12% power loss, slight fuel consumption increase, and normal smoke emissions. Combustion efficiency dropped slightly during the testing period. It can be concluded from this field study that the Diter diesel engine, without any modifications, ran successfully on a blend of 10% waste oil–90% diesel fuel without externally apparent damage to the engine parts. Nevertheless, it appears that the long–term use of waste oil blended with diesel fuel may need further testing before use as a viable energy solution.

Controller of compression-ignition engine

Abstract: A control system for a compression injection engine can prevent deterioration in exhaust purification at the time of the switching of combustion between spark ignition and compression ignition, at the time of said spark ignition combustion and said compression injection combustion, and can diagnose any deterioration of an NO x detector and a three way catalyst. The control system includes a catalytic converter installed within an exhaust passage of the compression ignition engine for compressing and igniting a pre-mixture of a fuel and air, an air/fuel ratio detector for detecting an air/fuel ratio at upstream side of said catalytic converter, and an NOx detector for detecting NOx at downstream side of said catalytic converter.

Emission and performance characteristics of neat ethanol fuelled Dl diesel engine

Abstract: SYNOPSIS Diesel engines are preferred power plants in the transportation sector due to their higher efficiency and lower operational cost. But the major problem of diesel engines is the emission of smoke, particulate matter and oxides of nitrogen (NOx) from its exhaust. Hence stringent emission regulations and the depletion of fossil fuels have necessitated a look at alternative fuels for internal combustion (I.C.) engines. Ethanol is an excellent fuel suitable for spark ignition (S.I.) engines, but has a very low cetane number and cannot be used in compression ignition engines unless gas temperatures are high enough at the time of fuel injection [1]. Different types of systems were developed to assist auto ignition of directly injected ethanol which include glow plugs or spark plugs, low heat rejection operation, and ignition improvers. This paper presents the use of 100% ethanol with ignition improver in a 4.4 kW single cylinder, direct injection, constant speed diesel engine. Experimental results indic...

Fuel injector having dual mode capabilities and engine using same

Abstract: A solitary fuel injector for a diesel engine that is capable of injecting fuel for a homogeneous charge compression ignition injection event, a conventional injection event. The solitary fuel injector also has a mixed mode that includes a homogeneous charge compression ignition injection and a conventional injection in a single compression stroke for the engine.

A study of low-comression-ratio dimethyl ether diesel engines

Abstract: A new concept of using dimethyl ether (DME) as an alternative fuel in direct injection compression ignition engines with low compression ratios was presented to seek a combustion regime wit...

Method of controlling ignition timing of compression ignition engine of premixed mixture type

Abstract: Provided is a method of controlling the timing of ignition of a compression ignition internal combustion engine of a premixed mixture type in which a premixed gas is self-ignited through compression by a piston, the volume of fuel spray impinging upon the inner wall surface of a combustion chamber is continuously or stepwise increased as the engine speed is changed from a low value to a high value, and which can optimumly control the timing of compression ignition in accordance with an operating condition of the engine at a low cost without complicating the apparatus configuration.

Operation of a Compression Ignition Engine on Diesel-Diethyl Ether Blends

Abstract: A detailed investigation on the effect of using diesel-diethyl ether blends in a direct injection diesel engine has been carried out. Blends with 5, 10 & 15% by weight of diethyl ether were tested. The optimum quantity of diethyl ether was found as 10% based on the thermal efficiency. Tests were also conducted with the optimum quantity at an advanced injection timing. With this timing, the blend decreased the smoke & CO level drastically at all loads and increased the brake thermal efficiency at high loads with out affecting NO emissions. It also increased the peak heat release rate, peak pressure and maximum rate of pressure rise. It was concluded that 10% blend with injection timing slight advanced than base diesel operation is suitable.© 2002 ASME

Method for ignition and start up of a turbogenerator

Abstract: A method for ignition and start up of a gas turbine engine in which the fuel flow is supplied to the combustor at a substantially constant rate for ignition and the gas turbine engine is ramped up at a preset acceleration rate to a speed to provide a supply of combustion air to the combustor in order to achieve the correct fuel-to-air ratio for ignition.

Experimental investigation of a single cylinder diesel engine as a hybrid power unit for a series hybrid electric vehicle

Abstract: Performance and emission testing, for a single cylinder, four-stroke diesel engine, have been experimentally performed to determine the optimum operation conditions for this engine when used as a hybrid power unit (HPU). The studied operation parameters included; Brake Specific Fuel Consumption (BSFC), exhaust emission (NO/sub x/, CO, CO/sub 2/ and O/sub 2/) and engine life. The results indicate that the lowest BSFC of the engine is found when the engine runs around 1 kW charging load when the engine speed ranged between 1900 rpm-2700 rpm. As the speed of the engine is maintained constant, the minimum level of BSFC is below 300 g/kW.hr at around 1900 rpm. The engine best operation conditions, for low emission, are found at engine speed around 2500 rpm. It was found that the oxides of nitrogen remain within the acceptable level (below 180 ppm) for such a diesel engine.

A comparative study between diesel and dual-fuel engines: Performance and emissions

Abstract: The depletion of fossil fuels is understood by most energy users to be an inevitability. Researchers all over the world focus their attention on the development of various alternative fuels. It is believed that the use of compressed natural gas (CNG), as an alternative to conventional fuels will result in low levels of emissions. However, the use of CNG as the main fuel in a diesel engine with the diesel fuel used as an igniter has always been associated with some problems. The main problem in such a dual-fuel engine is the increased tendency toward detonation because of the high compression ratio of the engine. The current work is an experimental investigation of such a problem. An extensive experimental program was carried out on a variable compression ratio Recardo E6 engine. The results of the current investigation indicate that the dual-fuel engine can operate detonation-free for a compression ratio of 16.5. The results also indicate that dual-fuel engines are lower than diesel engines in brake therm...

Fuels for homogeneous charge compression ignition engines

Abstract: A fuel for a homogeneous charge compression ignition engine having a 95 V% distilled temperature by boiling point measurement in the range of about 35°C to about 350°C, a cetane number in the range of about 2 to about 120, and an octane number in the range of 10 to about 110. The invention also relates to a method of operating a homogeneous charge compression ignition engine of mixing a fuel with air and feeding the fuel into a combustion chamber.

Apparatus and a method for controlling a diesel engine

Abstract: In a diesel engine, heavy EGR lowers a combustion temperature, which greatly prolongs an ignition delay period and all fuel is injected within the ignition delay period, thereby performing a low-temperature premixed combustion. A crank angle from a fuel injection completion to an ignition start is made less than 15 degrees by advancing a fuel injection timing and/or prolonging a fuel injection period. As a result, an equivalent ratio distribution in a combustion chamber at an ignition start is controlled such that an equivalent ratio in the vicinity of a cylinder center is richer than in the vicinity of a cylinder wall and the equivalent ratio gradually changes from the cylinder center to the cylinder wall.

Ignition timing control of homogeneous charge compression ignition engines by pulsed flame jets

Abstract: In diesel engines, most of the fuel is burned in a diffusion combustion phase, which inherently leads to the formation of excessive amounts of soot and NOx emissions. In order to decrease soot and NOx emissions simultaneously, the concept of a lean homogeneous charge compression ignition engine has been proposed. The onset of the combustion of the engine depends on the autoignition of the fuel, so it is quite difficult to control the ignition timing. On the other hand, it has been revealed that Pulsed Flame Jet (PFJ) has a great potential to enhance ignition reliability and burning rate in lean mixtures. In this article, autoignition characteristics of n -butane/air mixtures in a rapid compression machine (RCM) were shown first. The appearance of low temperature flames was observed in autoignition of n -butane in the RCM used here, and it was realized that the final compression conditions in the RCM correspond to the upper end of the low-temperature range of the positive temperature dependence region of i...

Mechanism of hydrocarbon reduction using multiple injection in a natural gas fuelled/micro-pilot diesel ignition engine

Abstract: Research has shown that a large amount of natural gas (NG) is unburned at light loads in an NG fuelled/micro-pilot diesel compression ignition engine. A mechanism of unburned hydrocarbon (HC) reduction using multiple injections of micro-pilot diesel has been proposed in this paper. Multidimensional computations were carried out for a dual-fuel engine based on a modified CAT3401 engine configuration. The computations show that a split injection with a small percentage (e.g. 30 per cent of diesel in the second injection pulse) can significantly reduce HC, CO and NOx emissions. Based on parametric studies to optimize the timing of both of the injection pulses, HC emissions could be reduced by 90 per cent, with a reduction in CO emissions of 50 per cent and NOx emissions of 70 per cent in comparison to a single-injection pulse-base case configuration.

Power and Emission Characteristics of DI Diesel Engine with a Soybean Bio-diesel Fuel

Abstract: This paper describes the power performance and emission characteristics of the high speed direct injection diesel engine (2.9 litter displacements) driven by soybean oil asknown a bio diesel fuel. The results were compared to diesel fuel with blending bio diesel fuels. The soybean bio diesel fuel was added in the diesel fuel in concentration varying from 25% to 75% volume rates. We measured the emissions according to ECE 13 mode and full load, fixedengine speed. When the 25% bio diesel fuel was used, NOx emission at the ECE 13 mode test slightly decreased compared with diesel base engine. Over engine speed of 2000 rpm, the level of unburned hydrocarbon(HC) and carbon monoxide(CO) were the same to the diesel engine. Smoke emission decreased asthe blending bio diesel fuel rate increased.

Emission and Performance Characteristics of a Single Cylinder Compression Ignition Engine Operating on Esterified Rice Bran Vegetable Oil and Diesel Fuel

Abstract: The alkyl monoesters of fatty acids derived from vegetable oils or animal fats, known as bio diesel, are attracting considerable interest as an alternative fuel for diesel engines. Biodiesel-fueled engines produce less carbon monoxide, unburnt hydrocarbons, and particulate emissions than diesel-fueled engines. However, bio diesel has different chemical and physical properties than diesel fuel, including a larger bulk modulus and a higher cetane number. Some of these properties can be affected by oxidation of the fuel during storage. These changes can affect the timing of the combustion process and potentially increase the emissions of oxides of nitrogen. The objective of this study was to evaluate the effect of injection and combustion timing on bio diesel combustion and exhaust emissions. Bio diesel fuel is a clean burning fuel made from natural renewable sources such as rice bran vegetable oil. Bio diesel operates in compression ignition engines similar to diesel fuel. It can be burnt in any standard unmodified diesel engine blended with 20% to 30% bio diesel with diesel. Rice bran oil can be converted into bio diesel fuel as ethyl ester by transestirification. Experimental investigations have been carried out using bio diesel as an alternative fuel in single cylinder, compression ignition engine under varying operating conditions and by varying the injection timings with respect to TDC. In this work various parameters such as brake power, peak pressure rise, and emissions during combustion process under varying operating conditions with diesel, bio diesel, bio diesel blends were measured. The exhaust emissions from the engine were measured using exhaust gas analyzer.Copyright © 2002 by ASME

Oil from Pistachia Palestine as a fuel

Abstract: In this study Pistachia Palestine (PP) oil was extracted and tested for its heating value, flash point and distillation characteristics. The oil was mixed with diesel fuel in different fraction and the heating value and flash points were obtained. The oil and diesel fuel was characterized by the measurement of their densities and viscosities. The results obtained showed that the oil produced from PP has the potential to act as a fuel or even an additive to diesel fuel. The study reveals the effect of PP oil–diesel fuel blends on the performance of indirect diesel engine (type Lister 8/1). The PP oil–diesel fuel blends were used in test engine operations with a wide range of engine speed at full load condition. Successful results were obtained without any engine modifications. It was also shown that the addition of PP oil to the diesel fuel decreases both the brake power and thermal efficiency of the test engine and increases the brake specific fuel consumption. This is due to the lower heating value of the PP oil compared to diesel fuel.

Kit and method for converting a diesel engine to natural gas engine

Abstract: A kit and method for converting a compression ignition diesel engine into a spark ignition natural gas engine is disclosed. The kit includes a throttle body, a fuel management system, a timing module, a means for reducing a compression ratio of a piston in the diesel engine, and a means for providing a spark in a cylinder of the natural gas engine. The method includes the steps of providing a diesel engine, machining one or more cylinder heads on the diesel engine to accept one or more spark plugs, machining a top surface of one or more pistons of the diesel engine to increase the volume of the one or more combustion chambers when the one or more pistons are located at top dead center in the diesel engine, providing a fuel management system to deliver the air/fuel mixture to the one or more combustion chambers, and providing a timing module to monitor the position of one or more camshafts on the diesel engine and provide piston position information to the fuel management system.