Showing papers on "Four-stroke engine published in 2010"

System for cranking internal combustion engine by engagement of pinion with ring gear

Abstract: In a system for driving a starter with a pinion so that the starter rotates a ring gear coupled to a crankshaft of an internal combustion engine to crank the internal combustion engine during a drop of a rotational speed of the crankshaft by automatic-stop control of the internal combustion engine, a predictor predicts a future trajectory of the drop of the rotational speed of the crankshaft based on information associated with the drop of the rotational speed of the crankshaft. A determiner determines a timing of the driving of the starter based on the future trajectory of the drop of the rotational speed of the internal combustion engine.

Misfire identification in a four-stroke four-cylinder petrol engine using decision tree

Abstract: Misfire detection in an internal combustion engine is very crucial to maintain optimum performance throughout its service life and to reduce emissions. The vibration of the engine block contains indirect information regarding the condition of the engine. Misfire detection can be achieved by processing the vibration signals acquired from the engine using a piezoelectric accelerometer. This hidden information can be decoded using statistical parameters like kurtosis, standard deviation, mean, median, etc. This paper illustrates the use of decision tree as a tool for feature selection and feature classification. The effect of dimension, minimum number of objects and confidence factor on classification accuracy are studied and reported in this work.

Lost motion variable valve actuation system for engine braking and early exhaust opening

Abstract: A method and system for actuating an internal combustion engine exhaust vaive to provide compression release actuation during an engine braking mode of engine operation and early exhaust valve opening actuation during a positive power mode of engine operation is disclosed. The system may include a first cam having a compression release lobe and an early exhaust valve opening lobe connected to a hydraulic lost motion system including a first rocker arm. A hydraulically actuated piston may be selectively extended from the hydraulic lost motion system to provide the exhaust valve with compression release actuation or early exhaust valve opening actuation. The hydraulicaily actuated piston may be provided as a slave piston in a master-slave piston circuit in a fixed housing, or alternatively, as a hydraulic piston slidably disposed in a rocker arm. The method and system may further provide exhaust gas recirculation and/or brake gas recirculation in combination with compression release actuation and early exhaust valve opening actuation.

Two-stroke engine with low consumption and low emissions

Abstract: Two-stroke engine ( 10 ) including an engine cylinder ( 18 ), a piston ( 20 ) sliding in the engine cylinder ( 18 ), an air pump ( 9 ), a main pipe ( 32 ) connected to the air pump ( 9 ) that communicates with the engine cylinder ( 18 ) through a plurality of scavenging pipes ( 28 ) opening into the cylinder immediately above the piston ( 20 ) in its bottom dead center position, an exhaust pipe also opening into the cylinder ( 18 ) immediately above the piston ( 20 ) in its bottom dead center position, an auxiliary pipe ( 29 ) branching from the main pipe ( 32 ) and opening into the cylinder ( 18 ) at a level higher than the scavenging pipes ( 28 ) and exhaust pipes ( 33 ), and a valve ( 30 ) capable of selectively opening and closing the auxiliary pipe ( 29 ) and configured to supercharge and decompress the cylinder ( 18 ) during the engine start-up phase.

Effect of hydroxy (HHO) gas addition on performance and exhaust emissions in compression ignition engines

Abstract: In this study, hydroxy gas (HHO) was produced by the electrolysis process of different electrolytes (KOH(aq), NaOH(aq), NaCl(aq)) with various electrode designs in a leak proof plexiglass reactor (hydrogen generator) Hydroxy gas was used as a supplementary fuel in a four cylinder, four stroke, compression ignition (CI) engine without any modification and without need for storage tanks Its effects on exhaust emissions and engine performance characteristics were investigated Experiments showed that constant HHO flow rate at low engine speeds (under the critical speed of 1750 rpm for this experimental study), turned advantages of HHO system into disadvantages for engine torque, carbon monoxide (CO), hydrocarbon (HC) emissions and specific fuel consumption (SFC) Investigations demonstrated that HHO flow rate had to be diminished in relation to engine speed below 1750 rpm due to the long opening time of intake manifolds at low speeds This caused excessive volume occupation of hydroxy in cylinders which prevented correct air to be taken into the combustion chambers and consequently, decreased volumetric efficiency was inevitable Decreased volumetric efficiency influenced combustion efficiency which had negative effects onengine torque andexhaust emissionsTherefore, ahydroxy electroniccontrol unit (HECU)wasdesignedandmanufacturedtodecreaseHHOflowratebydecreasingvoltageand

Turbocharged reciprocating piston engine having a connected pressure tank for bridging turbo lag, and method for operating said engine

Abstract: The present invention relates to a turbocharged reciprocating piston engine having a combustion chamber, and to a method for operating said engine. The combustion chamber has at least one inlet valve (10), one outlet valve (13) and at least one additional charging valve (11), for the additional feed of compressed air to bridge the turbo lag. All the valves (10, 11, 13) are operatively connected to the crankshaft via a camshaft and the operative connection of the charging valves to the crankshaft can be deactivated, with the result that the at least one charging valve (11) remains closed. The correct metering of the air for a stoichiometric or approximately stoichiometric combustion mixture is additionally achieved by a turbocharger (4) and a throttle valve (8). By displacement of the opening instant of the charging valves (11), air can be pumped from the cylindrical combustion chambers into the compressed air tank (14), instead of removing said air from the latter. Furthermore, an additional compressor (24), driven by the crankshaft, can likewise deliver air into the compressed air tank (14) if required.

Hydraulic Internal Combustion Engines

Abstract: Hydraulic internal combustion engines having at least one combustion piston not mechanically connected to a crankshaft or any other combustion piston, but instead acting on hydraulic plungers through valving that is electronically controlled to control the piston position and velocity, typically through an intake stroke, a compression stroke, a combustion or power stroke and an exhaust stroke. Electronically controlled fuel injection and electronically controlled engine valves provided great flexibility in the operating cycles that may be used, with the engine pumping hydraulic fluid to a high pressure accumulator for use in hydraulic motors or other hydraulic equipment. Embodiments using high pressure air injection to sustain combustion are also disclosed.

Single plane mount system for gas turbine engine

Abstract: A mounting system for a gas turbine engine assembly includes a plurality of mounting links attached the gas turbine engine along a single plane transverse to the engine centerline for separating the loads from the core engine

Performance and emission characteristics of a 4 stroke c.i. engine operated on honge methyl ester using artificial neural network

Abstract: In wake of the present energy environment crises it has become essential to identify renewable and alternative clean burning fuels. One of the significant routes to tackle the problem of increasing prices and the pollution problems of petroleum fuels is by the use of vegetable oil fuels known as biodiesels. In the present work biodiesel was prepared from Honge oil (Pongamia) and used as a fuel in C.I engine. Performance studies were conducted on a single cylinder fourstroke water-cooled compression ignition engine connected to an eddy current dynamometer. Experiments were conducted for different percentage of blends of Honge oil with diesel at various compression ratios. Experimental investigation on the Performance parameters and Exhaust emissions from the engine were done. Artificial Neural Networks (ANNs) were used to predict the Engine performance and emission characteristics of the engine. To train the network compression ratio, blend percentage, percentage load were used as the input variables where as engine performance parameters together with engine exhaust emissions were used as the output variables. Experimental results were used to train the ANN. Back-propagation algorithm was used to train the network. ANN results showed good correlation between the ANN predicted values and the desired values for various engine performance values and the exhaust emissions. The R 2 values were very close to 1 and the mean relative error values were less than 9 percent.

Free piston engine

Abstract: A free-piston engine comprising an engine cylinder and a single piston member comprising a double-ended piston configured to move within the cylinder, wherein the piston member partitions the cylinder into two separate chambers, each of which are supplied with a compressible working fluid from one or more intake means, the piston being arranged to move over and past the intake means during each stroke such that the fluid is replenished within one chamber while the piston compresses the fluid held in the other chamber.

Performance of tobacco oil-based bio-diesel fuel in a single cylinder direct injection engine

Abstract: In the present investigation, the high viscosity tobacco oil, which has been considered as non-edible oil as a potential alternative fuel for the Compression Ignition Engine (C. I.). Tobacco Methyl Ester (TME) was prepared by transesterification of raw tobacco oil. A two stage transestirification process was developed since tobacco is having higher acidic value. Transesterification was done using NaOH in the presence of sulphuric acid as catalyst and both acid transesterification and base transestirification was performed. Since TME has higher kinematic viscosity, its viscosity has been reduced by blending with neat diesel. The bio-diesel was blended with neat diesel at various volumetric proportions of B2, B5 (denoting 2, 5%) .The performance of this alternate fuel was tested by conducting a series of tests on 4 stroke single cylinder 5.2 kW direct injection diesel engine. The engine was run at different loads like full load, 3/4, 1/2, 1/4 and no load at various speeds and also at constant speed .The tests were conducted by using neat diesel and also diesel fuel blended with TME The combustion characteristics and exhaust emissions like hydrocarbon (HC), carbon (II) oxide (CO) and nitric oxides (NO) were measured. Torque, brake power, specific fuel consumption was also measured and the test was plotted in the graphs. The physical and chemical specifications like flash point, fire point, density, kinematic viscosity and acid number of TME were established. Significant improvement in engine performance was observed. The specific fuel consumption and the exhaust gas temperature reduced due to the decrease in viscosity of TME. From the properties and engine test results it has been established that at lower percentage of blending, TME has improved the engine performance but at higher percentages of blending, the performance and engine emissions were drastically effected. The results show that the TME can be used as an alternate fuel in diesel engines without any engine modifications. Key words: TME (Tobacco Methyl Ester), transesterification, diesel blend Bxx.

A comparative evaluation of Al2O3 coated low heat rejection diesel engine performance and emission characteristics using fuel as rice bran and pongamia methyl ester

Abstract: In this study, for the first time, a nanoceramic Al2O3 was used as a coating material in the low heat rejection engine concept Experiments were conducted on single cylinder, four stroke, water cooled, and direct injection diesel engine First, the engine was tested at different load conditions without coating Then, combustion chamber surfaces (cylinder head, cylinder liner, valves, and piston crown face) were coated with nanoceramic material of Al2O3 using plasma spray method Comparative evaluation on performance and emission characteristics using fuel as rice bran methyl ester, pongamia methyl ester, and biodiesel/diesel fuel mixtures was studied in the ceramic coated and uncoated engines under the same running conditions An increase in engine power and a decrease in specific fuel consumption, as well as significant improvements in exhaust gas emissions (except NOx) and smoke density, were observed in the ceramic coated engines compared with those of the uncoated engine

Free piston electromagnetic engine

Abstract: A converter converts mechanical energy of a piston to and from electrical energy during each piston cycle.

Method and system for controlling engine exhaust

Abstract: An engine having one of a plurality of exhaust valves in each cylinder that may be deactivated is disclosed. In one example, one exhaust valve of each cylinder is deactivated in response to engine speed. The engine may have improved engine torque at low engine speeds and reduced time to torque (e.g., turbo lag).

Un-throttling a direct injection gasoline homogeneous mixture engine with variable valve actuation:

Abstract: Two direct injection spark ignition (DISI) engines with identical combustion chamber geometries and fuel injection systems were used to investigate fuel economy, exhaust emissions, the in-cylinder flow field, the fuel spray behaviour and combustion characteristics with early inlet valve closure (EIVC) strategies aimed at reducing parasitic induction work owing to throttling. One engine had extensive optical access through a transparent piston crown and transparent cylinder liner, while the other all-metal engine allowed continuous running. Engine running focused at low and intermediate engine loads (∼ 3 and ∼ 6 bar indicated mean effective pressure) and two engine speeds (2000 and 3500 r/min). The results show that the indicated specific fuel consumption (ISFC) could be reduced by almost 6 per cent without significant deterioration in gaseous exhaust pollutant emissions. The results also show that the in-cylinder bulk flow and turbulence and the thermodynamic conditions during combustion are affected significantly by EIVC operation.

The Performance and Emissions Characteristics of a Diesel Engine Fueled with Biodiesel and Diesel Fuel

Abstract: This paper presents the performance and emission characteristics of a diesel engine fueled with biodiesel and diesel fuel. The tests were performed in a four stroke, single cylinder, naturally aspirated, air-cooled and direct injection diesel engine at the different engine speed under full-load conditions. The results obtained with biodiesel were compared with the diesel fuel as reference fuel. The engine torque and power obtained in biodiesel were less, and the specific fuel consumption was found to be higher, which could be attributed to lower calorific value of biodiesel. CO emissions for biodiesel were lower than that of diesel fuel. However, it was observed that NOx emissions for biodiesel were higher than that of diesel fuel.

Emission and Combustion Characteristics of Si Engine Working Under Gasoline Blended with Ethanol Oxygenated Organic Compounds

Abstract: Problem statement: The objective of this study is to investigate the effect of using unleaded gasoline and additives blends on Spark Ignition engine (SI engine) combustion and exhaust emission. Approach: A four stroke, single cylinder SI engine was used for conducting this study. Exhaust emissions were analysed for Carbon Monoxide (CO), Hydrocarbon (HC) and Oxides of Nitrogen (NOx) and carbon dioxide (CO2) using unleaded gasoline and additives blends with different percentages of fuel at varying engine torque condition and constant engine speed. Results: The result showed that the blending of unleaded gasoline increases the octane number and power output this may leads to increase the brake thermal efficiency. The CO, HC and NOx emissions concentrations in the engine exhaust decreases while the CO2 concentration increases. Conclusion: Using ethanol as a fuel additive to unleaded gasoline causes an improvement in combustion characteristics and significant reduction in exhaust emissions.

Variable volume crossover passage for a split-cycle engine

Abstract: An engine includes a crankshaft rotatable about a crankshaft axis. A compression piston is slidably received within a compression cylinder and operatively connected to the crankshaft such that the compression piston is operable to reciprocate through an intake stroke and a compression stroke during a single rotation of the crankshaft. An expansion (power) piston is slidably received within an expansion cylinder and operatively connected to the crankshaft such that the expansion piston is operable to reciprocate through an expansion stroke and an exhaust stroke during a single rotation of the crankshaft. A variable volume crossover passage interconnects the compression and expansion cylinders, and includes a variable volume housing to controllably regulate the air flow from the compression cylinder to the expansion cylinder.

Method and related system of dithering spark timing to prevent pre-ignition in internal combustion engine

Abstract: Methods of mitigating the occurrence of a low-speed pre-ignition event in a multi-cylinder internal combustion engine (10), the engine (10) having a computerized engine management control module (70) and an ignition timing module (66) controllable by the engine management control module (70). The computerized engine management module (70) monitors the operating conditions of the internal combustion engine (10) and at certain operating conditions dithers the ignition timing of at least one cylinder (20) of the engine (10) to induce light to medium SI engine knock temporarily. Due to the high temperature, high frequency pressure waves caused by SI engine knock, fuel and/or lubricant related deposits accumulated on combustion chamber components, i.e. top piston land crevices or piston crown, are consumed so that said deposits (60) cannot become a source of pre-ignition

Two-Stroke Engine, Sand Core for Producing a Two-Stroke Engine, and Method for Operating a Two-Stroke Engine

Abstract: A two-stroke engine has a cylinder with a combustion chamber and a reciprocating piston for driving a crankshaft. Transfer passages connect the crankcase in at least one position of the piston with the combustion chamber and open by piston-controlled transfer ports into the combustion chamber. An inlet opens into the crankcase and an outlet is provided at the combustion chamber. The engine is dividable into four sectors parallel to a longitudinal cylinder axis. The transfer port of a first transfer passage is arranged in the first sector, the outlet is arranged in the second sector, the transfer port of a second transfer passage is provided in the third sector, and the inlet is arranged in the fourth sector. Within the cylinder the first and second transfer passages, at a spacing from a separation plane between cylinder and crankcase, pass together into one of the second and fourth sectors.

Method for starting an internal combustion engine within a hybrid powertrain

Abstract: A hybrid powertrain includes an internal combustion engine, an electro-mechanical transmission and an electric machine. In an engine starting routine, flow control devices located proximate each combustion chamber in the engine initially restrict airflow into the cylinders to allow for a starter motor to rotate the engine at lower expansion and compression torque whereafter rotation of the engine is transitioned to the electric machine.

The effect of diesel fuel-Jatropha curcas oil methyl ester blend on the performance of a variable speed compression ignition engine

Abstract: The increase in crude oil prices, the problems associated with long term availability of conventional hydrocarbon fuels for automotive engines, and the continuous emission of combustion pollutants into the environment are cause for concern. These challenges have necessitated the need to investigate the performance of Jatropha curcas oil methyl ester as diesel fuel extender in compression ignition engines. A test rig of 2.43 kW, 165 F single cylinder -four stroke variable speed direct injection engine, and incorporated with a 1.25kVA Honda E 1500 A.C dynamometer manufactured by Ningbo Tri-circle Power Machinery Company, China and Honda Company, Japan, was used to conduct the engine performance tests on samples of fossil diesel fuel (DF), and diesel fuel containing 5%, 10%, 15%, and 20% by volume of Jatropha curcas oil methyl ester (i.e. B5, B10, B15, and B20 DF-JME blends) respectively. At maximum engine speed of 2600rpm, the brake power and brake mean effective pressure generated by DF-JME blends are somewhat comparable to fossil DF, with B10 and B20 samples exhibiting least engine power by the order of 1.80% and 2.72%. In terms of fuel consumption, B5, B10, B15 and B20 DF-JME blends are 1.63%, 3.06%, 0.030% and 0.514% higher than fossil DF. However, the lower break thermal efficiency could be attributed to the slow progress of combustion, lower heating value and combustion temperature of the DF-JME fuel mixture. Hence, it could be concluded from this study that transesterified Jatropha curcas oil is suitable for use as diesel fuel extender in compression ignition engines. To this effect, a deliberate investment in biodiesel production from Jatropha curcas oil will conserve crude oil reserve and improve Nigeria's energy security.

Effect of a semi electro-mechanical engine valve on performance and emissions in a single cylinder spark ignited engine

Abstract: In this study, an electro-mechanical valve (EMV) system for the intake valve of a four stroke, single cylinder, overhead valve and spark ignition (SI) engine was designed and constructed. An engine with the EMV system and a standard engine were tested to observe the effects of the EMV on engine performance and emissions at different speeds under full load. The EMV engine showed improved engine power, engine torque and break specific fuel consumption (BSFC). A 66% decrease in CO emissions was also obtained with the EMV system, but hydrocarbons (HC) and NOx emissions increased by 12% and 13% respectively.

Combustion, performance and emission analysis of diesel engine fuelled with methyl esters of Pongamia oil

Abstract: The methyl esters of vegetable oils, known as biodiesel are increasingly becoming popular because of their low environmental impact and potential as a green alternative fuel for diesel engine, and that they would not require significant modification of existing engine hardware. Methyl ester of Pongamia oil (PME) is derived through transesterification process. Experimental investigations have been carried out to examine properties, performance and emissions of different blends (B00, B20, B40, B60, B80 and B100) of PME comparison to diesel. A computer assisted single cylinder constant speed water cooled four stroke direct diesel engine (5 HP), which is commonly used in the agricultural sector for driving the pumps and small electrical generators is selected for the experimental investigation. The performance, emissions and combustion characteristics are analysed. The combustion parameters considered for this analysis are cylinder pressure and rate of heat release. The brake thermal efficiency is slightly reduced and hydrocarbon, carbon monoxide and smoke emissions in the exhaust are reduced when fuelled with methyl esters compared to diesel. But the NOx emissions are high when fuelled with methyl esters compared to diesel. [Received: December 11, 2009; Accepted: March 21, 2010]