Aspects Regarding the Influence of Lambda Control System Faults on Pollutant Emissions of Spark Ignition Engines

2016 ◽  
Vol 823 ◽  
pp. 291-296 ◽  
Author(s):  
Ion Lespezeanu ◽  
Florin Marius Militaru ◽  
Octavian Alexa ◽  
Constantin Ovidiu Ilie ◽  
Marin Marinescu
Keyword(s):  
Control System ◽  
Combustion Process ◽  
Fuel Mixture ◽  
Spark Ignition ◽  
Pollutant Emissions ◽  
Spark Ignition Engines ◽  
Engine Emissions ◽  
Exhaust Gases ◽  
Experimental Researches

Flow corrections established based on Lambda control system of spark ignition engines, determines in a decisively way the quality of air-fuel mixture. Faults in the operation of the control system generates deviations of the mixture composition from stoichiometric report, in this way affecting the entire combustion process in engine cylinders. This phenomenon leads, among others, to changes regarding the density of pollutant emissions from exhaust gases. In this context, this paper presents experimental researches made using the simulation of faults that may occur in the control system to highlight their influence on the concentration of engine emissions.

scholarly journals State of Art of Using Biofuels in Spark Ignition Engines

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 779
Author(s):  
Ashraf Elfasakhany
Keyword(s):  
Engine Performance ◽  
Spark Ignition ◽  
Pollutant Emissions ◽  
Spark Ignition Engines ◽  
Engine Emissions ◽  
Cold Starting ◽  
Starting Conditions ◽  
Unburned Hydrocarbons ◽  
Scientific Attention ◽  
State Of Art

Biofuels are receiving increased scientific attention, and recently different biofuels have been proposed for spark ignition engines. This paper presents the state of art of using biofuels in spark ignition engines (SIE). Different biofuels, mainly ethanol, methanol, i-butanol-n-butanol, and acetone, are blended together in single dual issues and evaluated as renewables for SIE. The biofuels were compared with each other as well as with the fossil fuel in SIE. Future biofuels for SIE are highlighted. A proposed method to reduce automobile emissions and reformulate the emissions into new fuels is presented and discussed. The benefits and weaknesses of using biofuels in SIE are summarized. The study established that ethanol has several benefits as a biofuel for SIE; it enhanced engine performance and decreased pollutant emissions significantly; however, ethanol showed some drawbacks, which cause problems in cold starting conditions and, additionally, the engine may suffer from a vapor lock situation. Methanol also showed improvements in engine emissions/performance similarly to ethanol, but it is poisonous biofuel and it has some sort of incompatibility with engine materials/systems; its being miscible with water is another disadvantage. The lowest engine performance was displayed by n-butanol and i-butanol biofuels, and they also showed the greatest amount of unburned hydrocarbons (UHC) and CO emissions, but the lowest greenhouse effect. Ethanol and methanol introduced the highest engine performance, but they also showed the greatest CO2 emissions. Acetone introduced a moderate engine performance and the best/lowest CO and UHC emissions. Single biofuel blends are also compared with dual ones, and the results showed the benefits of the dual ones. The study concluded that the next generation of biofuels is expected to be dual blended biofuels. Different dual biofuel blends are also compared with each other, and the results showed that the ethanol–methanol (EM) biofuel is superior in comparison with n-butanol–i-butanol (niB) and i-butanol–ethanol (iBE).

scholarly journals LES study on mixing and combustion in a Direct Injection Spark Ignition engine

2018 ◽  
Vol 73 ◽  
pp. 32
Author(s):  
Nicolas Iafrate ◽  
Anthony Robert ◽  
Jean-Baptiste Michel ◽  
Olivier Colin ◽  
Benedicte Cuenot ◽  
...  
Keyword(s):  
Ignition Time ◽  
Direct Injection ◽  
Combustion Process ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Pollutant Emissions ◽  
Spark Ignition Engines ◽  
Eddy Simulation ◽  
Mixture Preparation ◽  
The Impact

Downsized spark ignition engines coupled with a direct injection strategy are more and more attractive for car manufacturers in order to reduce pollutant emissions and increase efficiency. However, the combustion process may be affected by local heterogeneities caused by the interaction between the spray and turbulence. The aim for car manufacturers of such engine strategy is to create, for mid-to-high speeds and mid-up-high loads, a mixture which is as homogeneous as possible. However, although injection occurs during the intake phase, which favors homogeneous mixing, local heterogeneities of the equivalence ratio are still observed at the ignition time. The analysis of the mixture preparation is difficult to perform experimentally because of limited optical accesses. In this context, numerical simulation, and in particular Large Eddy Simulation (LES) are complementary tools for the understanding and analysis of unsteady phenomena. The paper presents the LES study of the impact of direct injection on the mixture preparation and combustion in a spark ignition engine. Numerical simulations are validated by comparing LES results with experimental data previously obtained at IFPEN. Two main analyses are performed. The first one focuses on the fuel mixing and the second one concerns the effect of the liquid phase on the combustion process. To highlight these phenomena, simulations with and without liquid injection are performed and compared.

scholarly journals A Numerical Study of a Simple Stochastic/ Deterministic Model of Cycle-to-Cycle Combustion Fluctuations in Spark Ignition Engines

2005 ◽  
Vol 11 (3) ◽  
pp. 371-379 ◽  
Author(s):  
G. Litak ◽  
M. Wendeker ◽  
M. Krupa ◽  
J. Czarnigowski
Keyword(s):  
Deterministic Model ◽  
Numerical Study ◽  
Fluid Model ◽  
Combustion Process ◽  
Fuel Mixture ◽  
Spark Ignition ◽  
Spark Ignition Engines ◽  
Fuel Feed ◽  
Lean Combustion ◽  
Two Fluid Model

We examine a simple, fuel-air model of combustion in a spark ignition (SI) engine with indirect injection. In our two-fluid model, variations of fuel mass burned in cycle sequences appear due to stochastic fluctuations of a fuel feed amount. We have shown that a small amplitude of these fluctuations affects considerably the stability of a combustion process strongly depending on the quality of the air-fuel mixture. The largest influence was found in the limit of a lean combustion. The possible effect of nonlinearities in the combustion process has been also discussed.

Estimation of Wiebe Function Parameters for Syngas and Anode Off-Gas Combustion in Spark-Ignition Engines

2021 ◽  
Author(s):  
Ruinan Yang ◽  
Zhongnan Ran ◽  
Dimitris Assanis
Keyword(s):  
Combustion Process ◽  
Fuel Mixture ◽  
Spark Ignition ◽  
Spark Ignition Engines ◽  
Si Engine ◽  
Gas Combustion ◽  
Engine Combustion ◽  
Comparable Accuracy ◽  
Fuel Mass Fraction ◽  
Wiebe Function

Abstract Wiebe functions, analytical equations that estimate the fuel mass fraction burned (MFB) during combustion, have been effective at describing spark-ignition (SI) engine combustion using gasoline fuels. This study explores if the same methodology can be extended for SI combustion with syngas, a gaseous fuel mixture composed of H2, CO, and CO2, and anode-off gas; the latter is an exhaust gas mixture emitted from the anode of a Solid Oxide Fuel Cell, containing H2, CO, H2O, and CO2. For this study, anode off-gas is treated as a syngas fuel diluted with CO2 and vaporized water. Combustion experiments were run on a single-cylinder, research engine using syngas and anode-off gas as fuels. One single Wiebe function and three double Wiebe functions were fitted and compared with the MFB profile calculated from the experimental data. It was determined that the SI combustion process of both the syngas and the anode-off gas could be estimated using a governing Wiebe function. While the detailed double Wiebe function had the highest accuracy, a reduced double Wiebe function is capable of achieving comparable accuracy. On the other hand, a single Wiebe function is not able to fully capture the combustion process of a SI engine using syngas and anode off-gas.

scholarly journals Numerical Study of Engine Performance and Emissions for Port Injection of Ammonia into a Gasoline\Ethanol Dual-Fuel Spark Ignition Engine

2021 ◽  
Vol 11 (4) ◽  
pp. 1441
Author(s):  
Farhad Salek ◽  
Meisam Babaie ◽  
Amin Shakeri ◽  
Seyed Vahid Hosseini ◽  
Timothy Bodisco ◽  
...  
Keyword(s):  
Numerical Study ◽  
Combustion Process ◽  
Engine Performance ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Combustion Model ◽  
Dual Fuel ◽  
Spark Ignition Engines ◽  
Performance And Emissions ◽  
Hc Emissions

This study aims to investigate the effect of the port injection of ammonia on performance, knock and NOx emission across a range of engine speeds in a gasoline/ethanol dual-fuel engine. An experimentally validated numerical model of a naturally aspirated spark-ignition (SI) engine was developed in AVL BOOST for the purpose of this investigation. The vibe two zone combustion model, which is widely used for the mathematical modeling of spark-ignition engines is employed for the numerical analysis of the combustion process. A significant reduction of ~50% in NOx emissions was observed across the engine speed range. However, the port injection of ammonia imposed some negative impacts on engine equivalent BSFC, CO and HC emissions, increasing these parameters by 3%, 30% and 21%, respectively, at the 10% ammonia injection ratio. Additionally, the minimum octane number of primary fuel required to prevent knock was reduced by up to 3.6% by adding ammonia between 5 and 10%. All in all, the injection of ammonia inside a bio-fueled engine could make it robust and produce less NOx, while having some undesirable effects on BSFC, CO and HC emissions.

scholarly journals Effect of Fuel and Air Dilution on Syngas Combustion in an Optical SI Engine

Energies ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1566 ◽  
Author(s):  
S.D. Martinez-Boggio ◽  
S.S. Merola ◽  
P. Teixeira Lacava ◽  
A. Irimescu ◽  
P.L. Curto-Risso
Keyword(s):  
Internal Combustion Engines ◽  
Combustion Process ◽  
Visible Spectrum ◽  
Propagation Speed ◽  
Fuel Mixture ◽  
Operating Conditions ◽  
Inert Gases ◽  
Pollutant Emissions ◽  
Si Engine ◽  
Lean Burn

To mitigate the increasing concentration of carbon dioxide in the atmosphere, energy production processes must change from fossil to renewable resources. Bioenergy utilization from agricultural residues can be a step towards achieving this goal. Syngas (fuel obtained from biomass gasification) has been proved to have the potential of replacing fossil fuels in stationary internal combustion engines (ICEs). The processes associated with switching from traditional fuels to alternatives have always led to intense research efforts in order to have a broad understanding of the behavior of the engine in all operating conditions. In particular, attention needs to be focused on fuels containing relatively high concentrations of hydrogen, due to its faster propagation speed with respect to traditional fossil energy sources. Therefore, a combustion study was performed in a research optical SI engine, for a comparison between a well-established fuel such as methane (the main component of natural gas) and syngas. The main goal of this work is to study the effect of inert gases in the fuel mixture and that of air dilution during lean fuelling. Thus, two pure syngas blends (mixtures of CO and H2) and their respective diluted mixtures (CO and H2 with 50vol% of inert gases, CO2 and N2) were tested in several air-fuel ratios (stoichiometric to lean burn conditions). Initially, the combustion process was studied in detail by traditional thermodynamic analysis and then optical diagnostics were applied thanks to the optical access through the piston crown. Specifically, images were taken in the UV-visible spectrum of the entire cycle to follow the propagation of the flame front. The results show that hydrogen promotes flame propagation and reduces its distortion, as well as resulting in flames evolving closer to the spark plug. All syngas blends show a stable combustion process, even in conditions of high air and fuel dilution. In the leanest case, real syngas mixtures present a decrease in terms of performance due to significant reduction in volumetric efficiency. However, this condition strongly decreases pollutant emissions, with nitrogen oxide (NOx) concentrations almost negligible.

scholarly journals Numerical investigations on hydrogen-enhanced combustion in ultra-lean gasoline spark-ignition engines

2019 ◽  
pp. 146808741987068 ◽  
Author(s):  
Nicolas Iafrate ◽  
Mickael Matrat ◽  
Jean-Marc Zaccardi
Keyword(s):  
Ignition Delay ◽  
Combustion Process ◽  
Spark Ignition ◽  
Combustion Stability ◽  
Spark Ignition Engines ◽  
Numerical Investigations ◽  
Ignition Delay Times ◽  
Auto Ignition ◽  
Delay Times ◽  
Combustion Speed

Performance of lean-burn gasoline spark-ignition engines can be enhanced through hydrogen supplementation. Thanks to its physicochemical properties, hydrogen supports the flame propagation and extends the dilution limits with improved combustion stability. These interesting features usually result in decreased emissions and improved efficiencies. This article aims at demonstrating how hydrogen can support the combustion process with a modern combustion system optimized for high dilution resistance and efficiency. To achieve this, chemical kinetics calculations are first performed in order to quantify the impacts of hydrogen addition on the laminar flame speed and on the auto-ignition delay times of air/gasoline mixtures. These data are then implemented in the extended coherent flame model and tabulated kinetics of ignition combustion models in a specifically updated version of the CONVERGE code. Three-dimensional computational fluid dynamics engine calculations are performed at λ = 2 with 3% v/v of hydrogen for two operating points. At low load, numerical investigations show that hydrogen enhances the maximal combustion speed and the flame growth just after the spark which is a critical aspect of combustion with diluted mixtures. The flame front propagation is also more isotropic when supported with hydrogen. At mid load, hydrogen improves the combustion speed and also extends the auto-ignition delay times resulting in a better knocking resistance. A maximal indicated efficiency of 48.5% can thus be reached at λ = 2 thanks to an optimal combustion timing.

scholarly journals A Fast CFD-Based Methodology for Determining the Cyclic Variability and Its Effects on Performance and Emissions of Spark-Ignition Engines

Energies ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 4131
Author(s):  
George M. Kosmadakis ◽  
Constantine D. Rakopoulos
Keyword(s):  
Spark Ignition ◽  
Pollutant Emissions ◽  
Computational Time ◽  
Spark Ignition Engines ◽  
Cyclic Variability ◽  
Indicated Mean Effective Pressure ◽  
Spark Plug ◽  
Performance And Emissions ◽  
Si Engines ◽  
Cyclic Variations

A methodology for determining the cyclic variability in spark-ignition (SI) engines has been developed recently, with the use of an in-house computational fluid dynamics (CFD) code. The simulation of a large number of engine cycles is required for the coefficient of variation (COV) of the indicated mean effective pressure (IMEP) to converge, usually more than 50 cycles. This is valid for any CFD methodology applied for this kind of simulation activity. In order to reduce the total computational time, but without reducing the accuracy of the calculations, the methodology is expanded here by simulating just five representative cycles and calculating their main parameters of concern, such as the IMEP, peak pressure, and NO and CO emissions. A regression analysis then follows for producing fitted correlations for each parameter as a function of the key variable that affects cyclic variability as has been identified by the authors so far, namely, the relative location of the local turbulent eddy with the spark plug. The application of these fitted correlations for a large number of engine cycles then leads to a fast estimation of the key parameters. This methodology is applied here for a methane-fueled SI engine, while future activities will examine cyclic variations in SI engines when fueled with different fuels and their mixtures, such as methane/hydrogen blends, and their associated pollutant emissions.

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