Origins of Hydrocarbon Emissions from a Multi-Fuel, Torch Ignition Assisted Direct Injection Engine

1986 ◽  
Vol 200 (1) ◽  
pp. 21-30 ◽  
Author(s):  
J A LoRusso ◽  
P H Havstad ◽  
E W Kaiser ◽  
W G Rothschild
Keyword(s):  
Chromatographic Analysis ◽  
Small Volume ◽  
Direct Injection ◽  
Single Point ◽  
Spark Ignition ◽  
Hydrocarbon Emissions ◽  
High Hydrocarbon ◽  
Hc Emissions ◽  
Volume Ignition ◽  
Tracer Experiments

Unthrottled, direct injection ignition assisted (DI–IA) engines have demonstrated DI diesel efficiencies and multi-fuel capabilities. However, high hydrocarbon (HC) emissions have been a problem with this concept. Torch ignition, provided by a separately fuelled small volume prechamber with spark ignition, was applied as a research tool to define the benefits of large volume ignition for controlling HC emissions. Torch ignition was found to be beneficial for HC control relative to the use of single point spark ignition; however, HC levels were higher than those observed from a DI diesel using low emissions technology. To assist in investigating the cause of the higher HC emissions, tracer experiments were conducted to verify that prechamber combustion characteristics did not contribute significantly to the total exhaust HC emissions. Separate, but similar, fuels were used for the main chamber and prechamber. Through gas chromatographic analysis of the major exhaust HC species, prechamber combustion was found to contribute substantially less than 20 per cent to the overall HC emissions for the engine conditions studied.

scholarly journals Study on the Effect of Second Injection Timing on the Engine Performances of a Gasoline/Hydrogen SI Engine with Split Hydrogen Direct Injecting

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5223
Author(s):  
Guanting Li ◽  
Xiumin Yu ◽  
Ping Sun ◽  
Decheng Li
Keyword(s):  
Numerical Study ◽  
Direct Injection ◽  
Mixture Distribution ◽  
Spark Ignition ◽  
Injection Timing ◽  
Si Engine ◽  
Excess Air ◽  
Crank Angle ◽  
Hc Emissions ◽  
Main Factor

Split hydrogen direct injection (SHDI) has been proved capable of better efficiency and fewer emissions. Therefore, to investigate SHDI deeply, a numerical study on the effect of second injection timing was presented at a gasoline/hydrogen spark ignition (SI) engine with SHDI. With an excess air ratio of 1.5, five different second injection timings achieved five kinds of hydrogen mixture distribution (HMD), which was the main factor affecting the engine performances. With SHDI, since the HMD is manageable, the engine can achieve better efficiency and fewer emissions. When the second injection timing was 105° crank angle (CA) before top dead center (BTDC), the Pmax was the highest and the position of the Pmax was the earliest. Compared with the single hydrogen direct injection (HDI), the NOX, CO and HC emissions with SHDI were reduced by 20%, 40% and 72% respectively.

Predicting Hydrocarbon Emissions From Direct Injection Diesel Engines

2002 ◽  
Vol 124 (3) ◽  
pp. 708-716 ◽  
Author(s):  
P. A. Lakshminarayanan ◽  
N. Nayak ◽  
S. V. Dingare ◽  
A. D. Dani
Keyword(s):  
Diesel Engines ◽  
Fuel Injection ◽  
Direct Injection ◽  
Injection System ◽  
Hydrocarbon Emissions ◽  
Operating Parameters ◽  
Fuel Injection System ◽  
Lean Combustion ◽  
Medium Speed ◽  
Hc Emissions

Hydrocarbon (HC) emissions from direct injection (DI) diesel engines are mainly due to fuel injected and mixed beyond the lean combustion limit during ignition delay and fuel effusing from the nozzle sac at low pressure. In the present paper, the concept has been developed to provide an elegant model to predict the HC emissions considering slow burning. Eight medium speed engines differing widely in bores, strokes, rated speeds, and power were studied for applying the model. The engines were naturally aspirated, turbocharged, or turbocharged with intercooling. The model has been validated by collecting data on HC emission, and pressures in the cylinder and in the fuel injection system from the experimental engines. New coefficients for the correlation of HC with operating parameters were obtained and these are different from the values published earlier, based on single-engine experiments.

scholarly journals Exhaust Emissions of a Medium Power Diesel Engine Operated with Biodiesel

2013 ◽  
Vol 8-9 ◽  
pp. 93-102 ◽  
Author(s):  
Nicolae Cordos ◽  
Adrian Todorut ◽  
István Barabás
Keyword(s):  
Diesel Fuel ◽  
Rapeseed Oil ◽  
Direct Injection ◽  
Cetane Number ◽  
Oxidation Stability ◽  
Acid Value ◽  
Hydrocarbon Emissions ◽  
Coke Content ◽  
Hc Emissions ◽  
Experimental Researches

The purpose of this study was to identify from experimental researches the results regarding the nitrogen oxides (NOx) emissions and hydrocarbon emissions (HC), emissions of a four-stroke, four cylinder, direct injection of a Romanian medium power diesel tractor engine at partial loads operating on diesel fuel (DF), rapeseed methyl ester (RME), degummed and filtered (5 μm) pure rapeseed oil (RO100) and its blends with diesel fuel: 20% pure rapeseed oil-80% diesel fuel (RO20), 50% pure rapeseed oil-50% diesel fuel (RO50), 75% pure rapeseed oil-25% diesel fuel (RO75) compared to diesel fuel. The main properties of the tested fuels (density, kinematic viscosity, oxidation stability, acid value, peroxide number, coke content, water content and cetane number) have been determined. The value of NOx emissions for the experimented biofuels is smaller up to 53% (for RO100) and increases up to 37% (for RO75) for different engine loads as compared to the diesel fuel. The HC emission shows a decrease for all biofuels used in the experiment ranging between 4% (for RO100) and 63% (RO75) at different loads relative to the diesel fuel.

Liquid Fuel Impingement on In-Cylinder Surfaces as a Source of Hydrocarbon Emissions From Direct Injection Gasoline Engines

2000 ◽  
Vol 123 (3) ◽  
pp. 659-668 ◽  
Author(s):  
J. Li ◽  
Y. Huang ◽  
T. F. Alger ◽  
R. D. Matthews ◽  
M. J. Hall ◽  
...  
Keyword(s):  
Steady State ◽  
Liquid Fuel ◽  
Computational Models ◽  
Fuel Injection ◽  
Direct Injection ◽  
Cylinder Liner ◽  
Gaseous Fuel ◽  
Hydrocarbon Emissions ◽  
Cylinder Surface ◽  
Hc Emissions

Hydrocarbon (HC) emissions from direct injection gasoline (DIG) engines are significantly higher than those from comparable port fuel injected engines, especially when “late” direct injection (injection during the compression stroke) is used to produce a fuel economy benefit via unthrottled lean operation. The sources of engine-out hydrocarbon emissions for late direct injection are bulk flame quench, low temperatures for post-combustion oxidation, and fuel impingement on in-cylinder walls. An experimental technique has been developed that isolates the wall impingement source from the other sources of HC emissions from DIG engines. A series of steady-state and transient experiments is reported for which the HC emissions due to operation with a premixed charge using a gaseous fuel are compared to those when a small amount of liquid fuel is injected onto an in-cylinder surface and the gaseous fuel flow rate is decreased correspondingly. The steady-state experiments show that wetting any in-cylinder surface dramatically increases HC emissions compared to homogeneous charge operation with a gaseous fuel. The results of the transient fuel injection interrupt tests indicate that liquid-phase gasoline can survive within the cylinder of a fully warmed-up firing engine and that liquid fuel vaporization is slower than current computational models predict. This work supports the argument that HC emissions from DIG engines can be decreased by reducing the amount of liquid fuel that impinges on the cylinder liner and piston, and by improving the vaporization rate of the fuel that is deposited on these surfaces.

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.

Soot Development in an Optical Direct Injection Spark Ignition Engine Fueled with Isooctane

2021 ◽  
Vol 22 (2) ◽  
pp. 455-463
Author(s):  
Fangxi Xie ◽  
Miaomiao Zhang ◽  
Yongzhen Wang ◽  
Yan Su ◽  
Wei Hong ◽  
...  
Keyword(s):  
Direct Injection ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Direct Injection Spark Ignition
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