Factors Determining Anti-Knocking Properties of Gaseous Fuels in Spark Ignition Gas Engines

2015 ◽  
Author(s):  
Hiroki Tanaka ◽  
Kazunobu Kobayashi ◽  
Takahiro Sako ◽  
Kazunari Kuwahara ◽  
Hiroshi Kawanabe ◽  
...  
Keyword(s):  
Specific Heat ◽  
Burning Velocity ◽  
Spark Ignition ◽  
Primary Component ◽  
Engine Operation ◽  
Specific Heat Ratio ◽  
Gaseous Fuels ◽  
Fuel Ratio ◽  
Secondary Fuel ◽  
High Specific Heat

The factors affecting knock resistance of fuels, including hydrogen (H2), ethane (C2H6), propane (C3H8), normal butane (n-C4H10), and iso-butane (i-C4H10), were determined using modeling and engine operation tests with spark-ignition gas engines. The results of zero-dimensional detailed chemical kinetic computations indicated that H2 had the longest ignition delay time of these gaseous fuels. Thus, H2 possessed the lowest ignitability. Results of engine operation tests indicated that H2 was the fuel most likely to result in knocking. The use of H2 as the fuel produced a temperature profile of the unburned gas compressed by the piston and flame front that was higher than that of the other fuels due to the high specific heat ratio and burning velocity of H2. The relation between knock resistance and secondary fuel ratio in methane-based fuel blends also was investigated using methane (CH4) as the primary component, and H2, C2H6, C3H8, n-C4H10, or i-C4H10 as the secondary components. When the secondary fuel ratio was small, the CH4/H2 blend possessed the lowest knocking tendency. But as the secondary fuel ratio increased, the CH4/H2 mixture possessed a greater tendency to knock than did CH4/C2H6 due to the high specific heat ratio and burning velocity of H2. These results indicate that the knocking that can occur with gaseous fuels is not only dependent on the ignitability of the fuel, but it also the specific heat ratio and burning velocity.

Factors Determining Antiknocking Properties of Gaseous Fuels in Spark-Ignition Gas Engines

2016 ◽  
Vol 138 (10) ◽  
Author(s):  
Hiroki Tanaka ◽  
Kazunobu Kobayashi ◽  
Takahiro Sako ◽  
Kazunari Kuwahara ◽  
Hiroshi Kawanabe ◽  
...  
Keyword(s):  
Specific Heat ◽  
Burning Velocity ◽  
Spark Ignition ◽  
Primary Component ◽  
Engine Operation ◽  
Specific Heat Ratio ◽  
Gaseous Fuels ◽  
Fuel Ratio ◽  
Secondary Fuel ◽  
High Specific Heat

The factors affecting knock resistance of fuels, including hydrogen (H2), ethane (C2H6), propane (C3H8), normal butane (n-C4H10), and iso-butane (i-C4H10), were determined using modeling and engine operation tests with spark-ignition gas engines. The results of zero-dimensional detailed chemical kinetic computations indicated that H2 had the longest ignition delay time of these gaseous fuels. Thus, H2 possessed the lowest ignitability. The results of engine operation tests indicated that H2 was the fuel most likely to result in knocking. The use of H2 as the fuel produced a temperature profile of the unburned gas compressed by the piston and flame front that was higher than that of the other fuels due to the high-specific heat ratio and burning velocity of H2. The relation between knock resistance and secondary fuel ratio in methane-based fuel blends also was investigated using methane (CH4) as the primary component, and H2, C2H6, C3H8, n-C4H10, or i-C4H10 as the secondary components. When the secondary fuel ratio was small, the CH4/H2 blend possessed the lowest knocking tendency. But as the secondary fuel ratio increased, the CH4/H2 mixture possessed a greater tendency to knock than CH4/C2H6 due to the high-specific heat ratio and burning velocity of H2. These results indicate that the knocking that can occur with gaseous fuels is not only dependent on the ignitability of the fuel but it also the specific heat ratio and burning velocity.

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.

Review on Combustion Control of Marine Engine by Fuzzy Logic Control Concerning the Air to Fuel Ratio

2014 ◽  
Vol 66 (2) ◽  
Author(s):  
Mohammad Javad Nekooei ◽  
Jaswar Jaswar ◽  
A. Priyanto
Keyword(s):  
Control Point ◽  
Nonlinear Behavior ◽  
Spark Ignition ◽  
Point Of View ◽  
Engine Operation ◽  
Marine Engine ◽  
Loop Control ◽  
Fuel Ratio ◽  
Highly Nonlinear ◽  
Close Loop Control

This research reviews a close loop control-oriented model, combined with air to fuel ratio, to regulate  combustion phasing in a spark- ignition marine engine operation. On the other hand ,Stoichiometric air-to-fuel ratio () control plays a significant role on the  three way catalysts in the reduction of exhaust pollutants of the SI marine engine. Air to fuel management for SI marine engines is a major challenge from the control point of view because of the highly nonlinear behavior of this system. For this reason, linear control techniques are unable to provide the required performance, and nonlinear controllers are used instead. Therefore, a fuzzy MIMO Control system is designed for robust control of  lambda. As an accurate and control oriented model, an  air to fuel ratio model of a Spark Ignition (SI) marine engine is developed to generate simulation data of the engine's subsystems. The Goal of this control is to maintain the A/F ratio at stoichiometry.

EFFECT OF AIR-FUEL RATIO ON SYNGAS COMBUSTION IN AN OPTICALLY ACCESSIBLE SPARK IGNITION ENGINE

2017 ◽  
Author(s):  
santiago daniel martinez boggio ◽  
Pedro Lacava ◽  
Maycon Silva ◽  
SIMONA MEROLA ◽  
Adrian Irimescu ◽  
...  
Keyword(s):  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Fuel Ratio ◽  
Syngas Combustion

Prediction of gaseous pollutant emissions from a spark-ignition direct-injection engine with gas-exchange simulation

2021 ◽  
pp. 146808742110050
Author(s):  
Stefania Esposito ◽  
Lutz Diekhoff ◽  
Stefan Pischinger
Keyword(s):  
Gas Exchange ◽  
Combustion Chamber ◽  
Direct Injection ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Operating Parameters ◽  
Gaseous Pollutant ◽  
Fuel Ratio ◽  
No Emissions

With the further tightening of emission regulations and the introduction of real driving emission tests (RDE), the simulative prediction of emissions is becoming increasingly important for the development of future low-emission internal combustion engines. In this context, gas-exchange simulation can be used as a powerful tool for the evaluation of new design concepts. However, the simplified description of the combustion chamber can make the prediction of complex in-cylinder phenomena like emission formation quite challenging. The present work focuses on the prediction of gaseous pollutants from a spark-ignition (SI) direct injection (DI) engine with 1D–0D gas-exchange simulations. The accuracy of the simulative prediction regarding gaseous pollutant emissions is assessed based on the comparison with measurement data obtained with a research single cylinder engine (SCE). Multiple variations of engine operating parameters – for example, load, speed, air-to-fuel ratio, valve timing – are taken into account to verify the predictivity of the simulation toward changing engine operating conditions. Regarding the unburned hydrocarbon (HC) emissions, phenomenological models are used to estimate the contribution of the piston top-land crevice as well as flame wall-quenching and oil-film fuel adsorption-desorption mechanisms. Regarding CO and NO emissions, multiple approaches to describe the burned zone kinetics in combination with a two-zone 0D combustion chamber model are evaluated. In particular, calculations with reduced reaction kinetics are compared with simplified kinetic descriptions. At engine warm operation, the HC models show an accuracy mainly within 20%. The predictions for the NO emissions follow the trend of the measurements with changing engine operating parameters and all modeled results are mainly within ±20%. Regarding CO emissions, the simplified kinetic models are not capable to predict CO at stoichiometric conditions with errors below 30%. With the usage of a reduced kinetic mechanism, a better prediction capability of CO at stoichiometric air-to-fuel ratio could be achieved.

Experimental Investigation of a Heavy-Duty Compression-Ignition Engine Retrofitted to Natural Gas Spark-Ignition Operation

2019 ◽  
Vol 141 (11) ◽  
Author(s):  
Jinlong Liu ◽  
Hemanth Kumar Bommisetty ◽  
Cosmin Emil Dumitrescu
Keyword(s):  
Natural Gas ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Compression Ignition ◽  
Heavy Duty ◽  
Compression Ignition Engine ◽  
Engine Operation ◽  
Cycle Variation ◽  
Spark Timing ◽  
Ci Engines

Heavy-duty compression-ignition (CI) engines converted to natural gas (NG) operation can reduce the dependence on petroleum-based fuels and curtail greenhouse gas emissions. Such an engine was converted to premixed NG spark-ignition (SI) operation through the addition of a gas injector in the intake manifold and of a spark plug in place of the diesel injector. Engine performance and combustion characteristics were investigated at several lean-burn operating conditions that changed fuel composition, spark timing, equivalence ratio, and engine speed. While the engine operation was stable, the reentrant bowl-in-piston (a characteristic of a CI engine) influenced the combustion event such as producing a significant late combustion, particularly for advanced spark timing. This was due to an important fraction of the fuel burning late in the squish region, which affected the end of combustion, the combustion duration, and the cycle-to-cycle variation. However, the lower cycle-to-cycle variation, stable combustion event, and the lack of knocking suggest a successful conversion of conventional diesel engines to NG SI operation using the approach described here.

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