THE OXIDATION, DECOMPOSITION, IGNITION, AND DETONATION OF FUEL VAPORS AND GASES: XVI. BENZENE AS A KNOCKING FUEL IN CONDITIONS PROMOTING THE FORMATION OF FINELY DIVIDED CARBON

1950 ◽  
Vol 28f (8) ◽  
pp. 308-314
Author(s):  
R. O. King ◽  
E. J. Durand ◽  
A. B. Allan
Keyword(s):  
Low Temperature ◽  
Combustion Chamber ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Otto Cycle ◽  
Liquid Drops ◽  
Air Supply

Experiments are described which demonstrate that benzene becomes a knocking fuel when used in a spark ignition Otto cycle engine if operating conditions are such that the vapor–air mixture becomes impregnated with finely divided carbon. The carbon was obtained on the impingement of the flame of burning benzene on relatively cool surfaces in the combustion chamber and by the burning of liquid drops dispersed in a combustible vapor–air mixture. The droplets were obtained by wet carburation even when the over-all mixture was weak; the engine being run with low temperature coolant, low temperature air supply, and with the carburetor attached directly to the engine head.

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.

Lean-Burn Characteristics of a Heavy-Duty Diesel Engine Retrofitted to Natural Gas Spark Ignition

2018 ◽  
Author(s):  
Jinlong Liu ◽  
Cosmin E. Dumitrescu
Keyword(s):  
Natural Gas ◽  
Combustion Chamber ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Combustion Stability ◽  
Fuel Injector ◽  
Heavy Duty ◽  
Lean Burn ◽  
Spark Timing ◽  
Heavy Duty Diesel

Increased utilization of natural-gas (NG) in the transportation sector can decrease the use of petroleum-based fuels and reduce greenhouse-gas emissions. Heavy-duty diesel engines retrofitted to NG spark ignition (SI) can achieve higher efficiencies and low NOx, CO, and HC emissions when operated under lean-burn conditions. To investigate the SI lean-burn combustion phenomena in a bowl-in-piston combustion chamber, a conventional heavy-duty direct-injection CI engine was converted to SI operation by replacing the fuel injector with a spark plug and by fumigating NG in the intake manifold. Steady-state engine experiments and numerical simulations were performed at several operating conditions that changed spark timing, engine speed, and mixture equivalence ratio. Results suggested a two-zone NG combustion inside the diesel-like combustion chamber. More frequent and significant late burn (including double-peak heat release rate) was observed for advanced spark timing. This was due to the chamber geometry affecting the local flame speed, which resulted in a faster and thicker flame in the bowl but a slower and thinner flame in the squish volume. Good combustion stability (COVIMEP < 3 %), moderate rate of pressure rise, and lack of knocking showed promise for heavy-duty CI engines converted to NG SI operation.

Lean-Burn Characteristics of a Heavy-Duty Diesel Engine Retrofitted to Natural-Gas Spark Ignition

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Jinlong Liu ◽  
Cosmin Emil Dumitrescu
Keyword(s):  
Natural Gas ◽  
Combustion Chamber ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Combustion Stability ◽  
Fuel Injector ◽  
Heavy Duty ◽  
Lean Burn ◽  
Heavy Duty Diesel ◽  
Ci Engines

Increased utilization of natural gas (NG) in the transportation sector can decrease the use of petroleum-based fuels and reduced greenhouse gas emissions. Heavy-duty diesel engines retrofitted to NG spark ignition (SI) can achieve higher efficiencies and low NOX, CO, and hydrocarbon (HC) emissions when operated under lean-burn conditions. To investigate the SI lean-burn combustion phenomena in a bowl-in-piston combustion chamber, a conventional heavy-duty direct-injection CI engine was converted to SI operation by replacing the fuel injector with a spark plug and by fumigating NG in the intake manifold. Steady-state engine experiments and numerical simulations were performed at several operating conditions that changed spark timing (ST), engine speed, and mixture equivalence ratio. Results suggested a two-zone NG combustion inside the diesel-like combustion chamber. More frequent and significant late-burn (including double-peak heat release rate) was observed for advanced ST. This was due to the chamber geometry affecting the local flame speed, which resulted in a faster and thicker flame in the bowl but a slower and thinner flame in the squish volume. Good combustion stability (COVIMEP < 3%), moderate rate of pressure-rise, and lack of knocking showed promise for heavy-duty CI engines converted to NG SI operation.

THE OXIDATION, IGNITION, AND DETONATION OF FUEL VAPORS AND GASES: XIII. THE 12:1 COMPRESSION RATIO PERFORMANCE OF THE C.F.R. SPARK IGNITION ENGINE USING TOWN GAS; COMPARISON WITH DIESEL ENGINES

1950 ◽  
Vol 28f (5) ◽  
pp. 134-155 ◽  
Author(s):  
R. O. King ◽  
E. J. Durand ◽  
Bernard D. Wood ◽  
A. B. Allan
Keyword(s):  
Compression Ratio ◽  
Thermal Efficiency ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Coolant Temperature ◽  
Otto Cycle ◽  
Air Supply ◽  
Standard Value ◽  
Gas Ratio ◽  
Gas Supply

The experiments described are part of a series being made to determine the factors which limit the power and efficiency of an Otto cycle spark ignition engine using Toronto town gas nearly free of sulphur. The air supply was unthrottled and power was varied by varying the gas supply. Mixture strength was "correct" at an air-to-gas ratio of 4:1. Trials were run with jacket coolant temperatures of 100°, 140°, 212°, and 295° F., the compression ratio being always 12:1 and the speed 900 r.p.m. A maximum indicated thermal efficiency of 43% was attained with coolant temperatures of 100° and 140° F. and an air-to-gas ratio of 8:1. Thermal efficiency diminished rapidly as air-to-gas ratio was increased and tended to become zero instead of the air standard value. The brake horsepower became zero for an air–gas ratio of approximately 11:1, the mixture strength being then 64% weak. Thus the engine was run at 900 r.p.m. from zero to full load, that is with 100% quality control. The maximum I.M.E.P. of 144 lb./sq. in. was obtained with a jacket coolant temperature of 100° F. The indicated thermal efficiency was then 36% and the mixture 10.7% rich. The performance of the Otto cycle engine could probably be improved by running at higher speeds but even at the relatively low speed of 900 r.p.m. for that type, it compared favorably in most respects with that of the compression ignition type of Diesel engine.

Two-Dimensional Temperature Distributions of Combustion Chamber Surfaces in a Firing Spark Ignition Engine

1994 ◽  
Vol 208 (2) ◽  
pp. 99-108 ◽  
Author(s):  
H Zhao ◽  
N Codings ◽  
T Ma
Keyword(s):  
Surface Temperature ◽  
Combustion Chamber ◽  
Thermal Imaging ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Two Dimensional ◽  
Warm Up ◽  
Temperature Distributions ◽  
Head Surface

This paper summarizes the development and application of advanced thermal imaging techniques to a spark ignition engine at the University of Cambridge Department of Engineering. A thermal imaging system is described which is capable of viewing and recording the cylinder head surface temperature and piston surface temperature in a firing spark ignition engine. Two-dimensional temperature distributions of these surfaces were measured both during the engine's warm-up period and steady state operations. The influence of the engine's operating conditions was examined upon the temperature distributions of combustion chamber surfaces during the engine's warm-up period. The effect of spark timings, particularly the onset of knocking combustion on the surface temperatures, has been studied.

scholarly journals INDUSTRIAL BURNERS TESTING AND COMBUSTION EFFICIENCY ANALYSIS

2002 ◽  
Vol 1 (2) ◽  
pp. 03
Author(s):  
J. Pimenta ◽  
L.C. De Lima ◽  
J.B.F. Duarte ◽  
R. M. Macedo
Keyword(s):  
Combustion Chamber ◽  
Experimental Testing ◽  
Combustion Process ◽  
Combustion Efficiency ◽  
Industrial Applications ◽  
Thermal Capacity ◽  
Operating Conditions ◽  
Air Supply ◽  
Commercial Applications ◽  
Energy Balance Approach

This paper describes experimental procedures and techniques adopted for combustion analysis during the testing of burners for industrial applications. The tests were carried out in the Combustion Technology Laboratory (NTC) of the University of Fortaleza. The NTC facilities are composed basically of experimental testing hall, a monitoring room, a chromatography laboratory and a modeling and simulation studies room. In the lab testing hall, is installed a test bench composed basically of the following parts : a combustion chamber with nominal thermal capacity of 1.000.000 kcal/h, two fully instrumented gas and air supply sections, a gas analyzer for emissions measurement, a panel for monitoring of water supply to combustion chamber coil, a cooling tower for heat delivery of combustion chamber. A data acquisition and control system is available with all the hardware tools for monitoring of the combustion process. With all the acquired measurements of temperature, flow rate, pressures, emissions, etc., the First Law energy balance approach was used in order to evaluate the combustion efficiency of two different burners with 378.000 and 403.200 kcal/h nominal heat power. Analysis of preliminary results allows representing the burners efficiency according to different air and fuel operating conditions. The experimental data obtained are also compared with simulation results from the modeling of the combustion process, presented in another article linked with this work, where a discussion of such comparison is made. Future studies will be dedicated to the development of improved efficiency combustion systems for industrial and commercial applications.

CFD modeling of pre-spark heat release in a boosted direct-injection spark-ignition engine

2021 ◽  
pp. 146808742110441
Author(s):  
Hengjie Guo ◽  
Roberto Torelli ◽  
James P Szybist ◽  
Sibendu Som
Keyword(s):  
Low Temperature ◽  
Heat Release ◽  
Chemical Kinetics ◽  
Ignition Delay ◽  
Direct Injection ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Detailed Chemistry ◽  
Direct Injection Spark Ignition

Accurate predictions of low-temperature heat release (LTHR) are critical for modeling auto-ignition processes in internal combustion engines. While LTHR is typically obscured by deflagration, extremely late ignition phasing can lead to LTHR prior to the spark, a behavior known as pre-spark heat release (PSHR). In this research, PSHR in a boosted direct-injection spark-ignition engine was studied using 3-D computational fluid dynamics (CFD) and detailed chemical kinetics. The turbulent combustion was modeled via a hybrid approach that incorporates the G-equation model for tracking the turbulent flame front, and the well-stirred reactor model with detailed chemistry for assessing the low-temperature reactions in unburnt gas. Simulations were conducted using Co-Optima alkylate and E30 fuels at operating conditions characterized by different PSHR intensities. The predicted in-cylinder pressure and heat release rate were found to agree well with experiments. It was found the estimate of previous-cycle trapped residuals is of utmost importance for capturing PSHR correctly. A simulation best practice was developed which keeps the detailed chemistry solver active throughout the entire simulation, allowing to track the evolution of intermediate species from one cycle to the next. Following the validation, the dynamics of PSHR were analyzed in detail employing the pressure-temperature (P-T) trajectory framework. It was shown that PSHR correlated with the first-stage ignition delay of the fuel, hence showing close relation to the in-cylinder P-T trajectory and the chemical kinetics. Besides, it was indicated that LTHR is a self-limiting process that has the effect of attenuating the thermal stratification in the combustion chamber. Furthermore, it was observed the occurrence of PSHR caused the P-T trajectory of end-gas to overlap with the negative temperature coefficient region of the fuel’s ignition-delay maps. This effect was more significant in the fuel-rich regions where engine knock tendency would be generally higher, with potential implications on knock control and mitigation.

Reduction of Unburnt Hydrocarbon Emissions from Spark Ignition Engines Using In-Cylinder Catalysts

1996 ◽  
Vol 210 (2) ◽  
pp. 123-129 ◽  
Author(s):  
Z Hu ◽  
N Ladommatos
Keyword(s):  
Combustion Chamber ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Chamber Wall ◽  
Cylinder Wall ◽  
Spark Ignition Engines ◽  
Piston Crown ◽  
Novel Approach ◽  
Wide Range ◽  
Hc Emissions

Exhaust unburnt hydrocarbons (HC) in spark ignition engines arise from a number of sources, including flame quenching at the entrance of crevice volumes and at the combustion chamber wall, absorption and desorption of fuel vapour into oil layers on the cylinder wall, partial burning and misfiring. All sources other than partial burning and misfiring are in close proximity to the wall surfaces of the combustion chamber. The significance of this observation is that unburnt HC emissions from spark ignition engines may be reduced at their sources of production using in-cylinder catalysts on the surfaces of the combustion chamber wall. This paper examines in detail a novel approach to reduce exhaust HC emissions using an in-cylinder catalyst on the combustion chamber walls, in particular, the surfaces of the crevice volumes. Platinum-rhodium coating on the piston crown led to a reduction of approximately 20 per cent in engine-out HC emissions over a wide range of engine operating conditions.

scholarly journals INDUSTRIAL BURNERS TESTING AND COMBUSTION EFFICIENCY ANALYSIS

2002 ◽  
Vol 1 (2) ◽  
Author(s):  
J. Pimenta ◽  
L.C. De Lima ◽  
J.B.F. Duarte ◽  
R. M. Macedo
Keyword(s):  
Combustion Chamber ◽  
Experimental Testing ◽  
Combustion Process ◽  
Combustion Efficiency ◽  
Industrial Applications ◽  
Thermal Capacity ◽  
Operating Conditions ◽  
Air Supply ◽  
Commercial Applications ◽  
Energy Balance Approach

This paper describes experimental procedures and techniques adopted for combustion analysis during the testing of burners for industrial applications. The tests were carried out in the Combustion Technology Laboratory (NTC) of the University of Fortaleza. The NTC facilities are composed basically of experimental testing hall, a monitoring room, a chromatography laboratory and a modeling and simulation studies room. In the lab testing hall, is installed a test bench composed basically of the following parts : a combustion chamber with nominal thermal capacity of 1.000.000 kcal/h, two fully instrumented gas and air supply sections, a gas analyzer for emissions measurement, a panel for monitoring of water supply to combustion chamber coil, a cooling tower for heat delivery of combustion chamber. A data acquisition and control system is available with all the hardware tools for monitoring of the combustion process. With all the acquired measurements of temperature, flow rate, pressures, emissions, etc., the First Law energy balance approach was used in order to evaluate the combustion efficiency of two different burners with 378.000 and 403.200 kcal/h nominal heat power. Analysis of preliminary results allows representing the burners efficiency according to different air and fuel operating conditions. The experimental data obtained are also compared with simulation results from the modeling of the combustion process, presented in another article linked with this work, where a discussion of such comparison is made. Future studies will be dedicated to the development of improved efficiency combustion systems for industrial and commercial applications.

scholarly journals Ethanol/Gasoline Blends as Alternative Fuel in Last Generation Spark-Ignition Engines: A Review on CO and HC Engine Out Emissions

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 4034
Author(s):  
Paolo Iodice ◽  
Massimo Cardone
Keyword(s):  
Physicochemical Properties ◽  
Alternative Fuels ◽  
Experimental Studies ◽  
Alternative Fuel ◽  
Exhaust Emissions ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Spark Ignition Engines ◽  
The Impact

Among the alternative fuels existing for spark-ignition engines, ethanol is considered worldwide as an important renewable fuel when mixed with pure gasoline because of its favorable physicochemical properties. An in-depth and updated investigation on the issue of CO and HC engine out emissions related to use of ethanol/gasoline fuels in spark-ignition engines is therefore necessary. Starting from our experimental studies on engine out emissions of a last generation spark-ignition engine fueled with ethanol/gasoline fuels, the aim of this new investigation is to offer a complete literature review on the present state of ethanol combustion in last generation spark-ignition engines under real working conditions to clarify the possible change in CO and HC emissions. In the first section of this paper, a comparison between physicochemical properties of ethanol and gasoline is examined to assess the practicability of using ethanol as an alternative fuel for spark-ignition engines and to investigate the effect on engine out emissions and combustion efficiency. In the next section, this article focuses on the impact of ethanol/gasoline fuels on CO and HC formation. Many studies related to combustion characteristics and exhaust emissions in spark-ignition engines fueled with ethanol/gasoline fuels are thus discussed in detail. Most of these experimental investigations conclude that the addition of ethanol with gasoline fuel mixtures can really decrease the CO and HC exhaust emissions of last generation spark-ignition engines in several operating conditions.

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