scholarly journals Determination of the optimal air-fuel ratio for upgraded biogas engine operation

2021 ◽  
Vol 327 ◽  
pp. 02009
Author(s):  
Radostin Dimitrov ◽  
Penka Zlateva
Keyword(s):  
Combustion Engine ◽  
Three Dimensional ◽  
Spark Ignition Engine ◽  
Engine Fuel ◽  
Load Range ◽  
Engine Operation ◽  
Operating Modes ◽  
Fuel Ratio ◽  
Ratio Variation ◽  
Test Engine

The paper reveals a study about air-fuel ratio variation of spark-ignition engine running on upgraded biogas (biomethane). Using biogas as internal combustion engine fuel and external mixture formation is a new approach to decrease harmful exhaust gas emissions. Тo obtain minimum concentrations of exhaust gases harmful emissions the engine must work with optimal air-fuel ratio. This research contains analysis of many test engine adjusting characteristics to determine optimal air-fuel ratio for each working regime and to obtain maximum effective working process by the use of biomethane as a fuel. Three-dimensional graphics of air-fuel ratio variation across the rpm and load range were made. In conclusion based on performed experiments, a table with values of air-fuel ratio for all engine operating modes and dependence on rpm and load of the engine is proposed.

Effects of Blending Gasoline With Ethanol and Butanol on Engine Efficiency and Emissions Using a Direct-Injection, Spark-Ignition Engine

2009 ◽  
Author(s):  
Christopher Cooney ◽  
Thomas Wallner ◽  
Steve McConnell ◽  
Jeffrey C. Gillen ◽  
Clint Abell ◽  
...  
Keyword(s):  
Alternative Fuels ◽  
Direct Injection ◽  
Substantial Reduction ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Engine Operation ◽  
Advanced Biofuels ◽  
Engine Calibration ◽  
Combustion Behavior ◽  
Test Engine

The new U.S. Renewable Fuel Standard requires an increase of ethanol and advanced biofuels to 36 billion gallons by 2022. Due to its high octane number, renewable character and minimal toxicity, ethanol was believed to be one of the most favorable alternative fuels to displace gasoline in spark-ignited engines. However, ethanol fuel results in a substantial reduction in vehicle range when compared to gasoline. In addition, ethanol is fully miscible in water which requires blending at distribution sites instead of the refinery. Butanol, on the other hand, has an energy density comparable to gasoline and lower affinity for water than ethanol. Butanol has recently received increased attention due to its favorable fuel properties as well as new developments in production processes. The advantageous properties of butanol warrant a more in-depth study on the potential for butanol to become a significant component of the advanced biofuels mandate. This study evaluates the combustion behavior, performance, as well as the regulated engine-out emissions of ethanol and butanol blends with gasoline. Two of the butanol isomers; 1-butanol as well as iso-butanol, were tested as part of this study. The evaluation includes gasoline as a baseline, as well as various ethanol/gasoline and butanol/gasoline blends up to a volume blend ratio of 85% of the oxygenated fuel. The test engine is a spark ignition, direct-injection, (SIDI), four-cylinder test engine equipped with pressure transducers in each cylinder. These tests were designed to evaluate a scenario in terms of using these alcohol blends in an engine calibrated for pump gasoline operation. Therefore no modifications to the engine calibration were performed. Following this analysis of combustion behavior and emissions with the base engine calibration, future studies will include detailed heat release analysis of engine operation without exhaust gas recirculation. Also, knock behavior of the different fuel blends will be studied along with unregulated engine out emissions.

scholarly journals Improving the effective efficiency of a spark ignition engine through the use of a fully independent valve control system

2021 ◽  
Author(s):  
Zbigniew Żmudka ◽  
Stefan Postrzednik
Keyword(s):  
Charge Exchange ◽  
Spark Ignition Engine ◽  
Theoretical Research ◽  
Si Engine ◽  
Load Range ◽  
Engine Operation ◽  
Engine Load ◽  
Effective Work ◽  
Partial Load ◽  
Valve Control

The article presents theoretical research of the proposed system of fully independent valve control (FIVC) of the SI engine. The analysis included controlling the movement of the intake valves, which results in adjusting the mass of the fresh charge to the current engine load, as well as the movement of the exhaust valves, where the main aim is to keep the rest of the exhaust gas in the cylinder, i.e. implementation of internal EGR. The open theoretical Seiliger-Sabathe cycle with the classic throttle regulation of load is the reference cycle for assessment of benefits and study of the effectiveness of obtaining work as a result of application of the FIVC system. A comparative analysis of the effectiveness of application of the proposed system was carried out based on the selected quantities: fuel dose, cycle work, relative work of charge exchange and cycle efficiency. The use of the FIVC to regulate the SI engine load makes it possible to eliminate the throttle and thus reduce the charge exchange work, especially in the partial load range. And this then leads to an increase in internal and effective work, which in turn results in an increase in the effective energy efficiency of an engine operation.

scholarly journals Measurement of the air-to-fuel ratio inside a passive pre-chamber of a fired spark-ignition engine

2020 ◽  
Vol 5 (3-4) ◽  
pp. 147-157
Author(s):  
Nicolas Wippermann ◽  
Olaf Thiele ◽  
Olaf Toedter ◽  
Thomas Koch
Keyword(s):  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Engine Operation ◽  
Ratio Measurement ◽  
Fuel Ratio ◽  
Mixture Preparation ◽  
Fuel Delivery ◽  
Absorption Of Light ◽  
Mass Flows ◽  
Motored Engine

Abstract This paper investigates the local air-to-fuel ratio measurement within the pre-chamber of a spark-ignition engine by determining the absorption of light from hydrocarbons using an infrared sensor. The measurement was performed during fired and motored engine operation points and compared to the more common exhaust lambda measurements. The experiment provided data to compare the mixture preparation in a hot and cold environment of pre-chamber and main combustion chamber. The experiment also gives an indication regarding the possible use of a pre-chamber sensor in a motored engine at higher boost pressures and fuel mass flows, operation points that would overheat the sensor in a fired engine. The work also includes the analysis of the fuel delivery into the pre-chamber of a direct and indirect injection engine. Furthermore, pressure and temperature measurement within the pre-chamber provides information about the critical sensor environment and helps to understand the gas exchange between the two volumes.

A Learning Algorithm for Optimal Internal Combustion Engine Calibration in Real Time

2007 ◽  
Author(s):  
Andreas A. Malikopoulos ◽  
Panos Y. Papalambros ◽  
Dennis N. Assanis
Keyword(s):  
Internal Combustion Engine ◽  
Real Time ◽  
Fuel Economy ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Pollutant Emissions ◽  
Engine Operation ◽  
Engine Calibration

Advanced internal combustion engine technologies have increased the number of accessible variables of an engine and our ability to control them. The optimal values of these variables are designated during engine calibration by means of a static correlation between the controllable variables and the corresponding steady-state engine operating points. While the engine is running, these correlations are being interpolated to provide values of the controllable variables for each operating point. These values are controlled by the electronic control unit to achieve desirable engine performance, for example in fuel economy, pollutant emissions, and engine acceleration. The state-of-the-art engine calibration cannot guarantee continuously optimal engine operation for the entire operating domain, especially in transient cases encountered in driving styles of different drivers. This paper presents the theoretical basis and algorithmic implementation for allowing the engine to learn the optimal set values of accessible variables in real time while running a vehicle. Through this new approach, the engine progressively perceives the driver’s driving style and eventually learns to operate in a manner that optimizes specified performance indices. The effectiveness of the approach is demonstrated through simulation of a spark ignition engine, which learns to optimize fuel economy with respect to spark ignition timing, while it is running a vehicle.

scholarly journals The analysis of spark ignition engine short-time supercharging

2009 ◽  
Vol 139 (4) ◽  
pp. 3-11
Author(s):  
Jarosław MAMALA
Keyword(s):  
Combustion Engine ◽  
Air Flow ◽  
Spark Ignition ◽  
Test Stand ◽  
Spark Ignition Engine ◽  
Engine Test ◽  
Engine Operation ◽  
Intake System ◽  
Short Time

The paper presents the analysis of improvement of spark ignition engine operation indexes by means of short-time supercharging. The simulation and engine test stand investigation results of the air flow in the spark ignition combustion engine intake system have been shown here.

Numerical Analysis of a Small Turbo-Charged Spark-Ignition Engine

2006 ◽  
Author(s):  
Gustavo Fontana ◽  
Enzo Galloni ◽  
Roberto Palmaccio ◽  
Enrico Torella
Keyword(s):  
Three Dimensional ◽  
Engine Performance ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Medium Size ◽  
Small Displacement ◽  
Engine Fuel ◽  
Passenger Cars ◽  
Ratio Distribution ◽  
Torque Values

The reduction of green-house gas emissions, that is the reduction of engine fuel consumption, is becoming a primary requirement for the automotive industry as well as meeting current and future emission legislations. Performing high torque values with small displacement engines, the so-called “downsizing”, permits, in general, to limit some typical engine losses (for instance: pumping and friction losses), increasing the overall engine efficiency. This means to improve vehicle fuel economy and, as a consequence, the CO2 emissions avoiding a performance decrease. In this paper, the behavior of a small displacement turbocharged spark-ignition engine prototype, for medium size passenger cars, has been analyzed. 3-D numerical simulations have been carried out in order to achieve a lot of information on engine performance and control parameters. Thus, at different engine operating points, intake and exhaust manifold pressure, volumetric efficiency, high pressure curves, the flow field of the fresh charge within the cylinder, the air to fuel ratio distribution, the residual gas fraction distribution and so long have been calculated. Since, as usual, the turbocharged version of the engine under study derives from an existing naturally aspirated engine, the purpose of this investigation is to obtain a detailed picture of the variations produced by turbo-charging on engine main parameters. The increase of knock risk due to higher cylinder pressures has been evaluated as well. Thanks to the three dimensional analysis, sound information have been obtained, so that suggestions for modifying some geometric engine parameters, according to the variations imposed by turbo-charging, have been proposed. Computations have been performed by means of the 3-D AVL Fire code. Initial and boundary conditions have been evaluated by means of 1-D, unsteady computations running separately from the 3-D code. The model utilized in this study has been validated by comparing the obtained results to the measured data provided by the research center of the engine manufacturer.

Reconstruction of Indicated Pressure Waveform in a Spark-Ignition Engine From Block Vibration Measurements

1997 ◽  
Vol 119 (4) ◽  
pp. 614-619 ◽  
Author(s):  
Piero Azzoni
Keyword(s):  
Combustion Engine ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Vibration Sensor ◽  
Pressure Waveform ◽  
Cylinder Pressure ◽  
Engine Operation ◽  
Knock Detection ◽  
Good Potential ◽  
On Line

Knowledge of the pressure waveform in each cylinder of a spark-ignition engine may provide useful diagnostic information concerning engine operation. This paper presents a method for the reconstruction of the indicated pressure waveform for each cylinder of a multicylinder internal combustion engine using engine block vibration signals. The method permits the reconstruction of the cylinder pressure waveform, cycle by cycle, during free accelerations. The procedure has good potential for application in end-of-assembly diagnostic tests, using a noncontacting laser velocimeter. The same signal processing method may be applicable on-board an automobile to perform an on-line cylinder-by-cylinder diagnostics, using the same vibration sensor used for knock detection in many production vehicles.

scholarly journals Turbocharged gasoline engine with separate exhaust valve configuration (TwinAV) – A simulation study

2020 ◽  
Author(s):  
Andreas Gotter ◽  
Alexander Gotter
Keyword(s):  
Gasoline Engine ◽  
Combustion Engine ◽  
Maximum Efficiency ◽  
Efficiency Gain ◽  
Load Range ◽  
Simple Method ◽  
Engine Operation ◽  
Load Optimization ◽  
Engine Model ◽  
Exhaust Heat

After decades of part-load optimization, increasing demands on maximum efficiency of the combustion engine are bringing technologies such as exhaust heat utilization into focus, particularly as the best operation point can be reached more often due to hybridization and new transmission concepts.Turbocharging is a common and simple method to utilize the exhaust heat of an internal combustion engine. However, static turbocharging exhibits the drawback of exhaust gas backpressure and thus increased residual gas mass in the cylinder.A promising concept to increase optimum efficiency is found in the TwinAV concept, which assigns valve individual cam timing and exhaust configuration. This concept has the capability to reduce the static backpressure in the load exchange loop, while enabling unlimited turbocharged operation.Within this work, a 1-D simulation model was adapted to an existing 4-cylinder gasoline TC engine. Subsequently the TwinAV concept was applied to this engine model and results were compared.In this research two possible layouts have been considered: The first layout is designed for full engine operation over the entire engine speed and load range. This layout demonstrates that the specific fuel consumption can be reduced by up to 6.4% at 23 bar IMEP, whereby a reduction of 2.5% could be achieved at 15 bar IMEP.The second layout was designed for steady-state operation with shorter cam event lengths. This layout shows a theoretical potential for up to 10% efficiency gain. An initial cost estimate shows that the costs per gram of CO2 saved are quite attractive.

Performance and Emissions Characteristics Investigation of a Bi-Fuel SI Engine Fuelled by CNG and Gasoline

2006 ◽  
Author(s):  
Abazar Shamekhi ◽  
Nima Khatibzadeh ◽  
Amir H. Shamekhi
Keyword(s):  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Engine Performance ◽  
Internal Combustion ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Engine Fuel ◽  
Wide Range ◽  
Performance And Emissions ◽  
Pollutant Sources

Nowadays, increased attention has been focused on internal combustion engine fuels. Regarding environmental effects of internal combustion engines particularly as pollutant sources and depletion of fossil fuel resources, compressed natural gas (CNG) has been introduced as an effective alternative to gasoline and diesel fuel in many applications. A high research octane number allows combustion at higher compression ratios without knocking and good emission characteristics of HC and CO are major benefits of CNG as an engine fuel. In this paper, CNG as an alternative fuel in a spark ignition engine has been considered. Engine performance and exhaust emissions have been experimentally studied for CNG and gasoline in a wide range of the engine operating conditions.

scholarly journals The use of partial fuel stratification to enable stable ultra-lean deflagration-based Spark-Ignition engine operation with controlled end-gas autoignition of gasoline and E85

2019 ◽  
Vol 21 (9) ◽  
pp. 1678-1695
Author(s):  
Zongjie Hu ◽  
Junjie Zhang ◽  
Magnus Sjöberg ◽  
Wei Zeng
Keyword(s):  
Thermal Efficiency ◽  
Direct Injection ◽  
Spark Ignition ◽  
Combustion Efficiency ◽  
Spark Ignition Engine ◽  
Load Range ◽  
Engine Operation ◽  
Lean Mixture ◽  
Stable Combustion ◽  
Fuel Stratification

Lean operation of Spark-Ignition engines can provide higher thermal efficiency compared to standard stoichiometric operation. However, for a homogeneous lean mixture, the associated reduction of flame speeds becomes an important issue from the perspective of robust ignition and fast flame spread throughout the charge. This study is focused on the use of a lean partial fuel stratification strategy that can stabilize the deflagration, while sufficiently fast combustion is ensured via the use of end-gas autoignition. The engine has a spray-guided Direct-Injection Spark-Ignition combustion system and was fueled with either a high-octane certification gasoline or E85. Partial fuel stratification was achieved using several fuel injections during the intake stroke in combination with a small pilot-injection concurrent with the Spark-Ignition. The results reveal that partial fuel stratification enables very stable combustion, offering higher thermal efficiency for parts of the load range in comparison to well-mixed lean and stoichiometric combustion. The heat release and flame imaging demonstrate that the combustion often has three distinct stages. The combustion of the pilot-injected fuel, ignited by the normal spark, acts as a “super igniter,” ensuring a very repeatable initiation of combustion, and flame incandescence reveals locally rich conditions. The second stage is mainly composed of blue flame propagation in a well-mixed lean mixture. The third stage is the compression autoignition of a well-mixed and typically very lean end-gas. The end-gas autoignition is critical for achieving high combustion efficiency, high thermal efficiency, and stable combustion. Partial fuel stratification enables very effective combustion-phasing control, which is critical for controlling the occurrence and intensity of end-gas autoignition. Comparing the gasoline and E85 fuels, it is noted that achieving end-gas autoignition for the higher octane E85 requires a more aggressive compression of the end-gas via the use of a more advanced combustion phasing or higher intake-air temperature.

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