scholarly journals Effect of methane on pilot-fuel auto-ignition in dual-fuel engines

2019 ◽  
Vol 37 (4) ◽  
pp. 4741-4749 ◽  
Author(s):  
Aleš Srna ◽  
Michele Bolla ◽  
Yuri M. Wright ◽  
Kai Herrmann ◽  
Rolf Bombach ◽  
...  
Keyword(s):  
Dual Fuel ◽  
Auto Ignition ◽  
Pilot Fuel ◽  
Dual Fuel Engines

scholarly journals Effects of Gasoline-Diesel Ratio on Combustion and Emission Characteristics of a Dual-Fuel CI Engine: A CFD Simulation

2021 ◽  
Author(s):  
Kazi Mostafijur Rahman ◽  
Md. Habibur Rahaman
Keyword(s):  
Internal Combustion Engines ◽  
Cfd Simulation ◽  
Dual Fuel ◽  
Ignition Process ◽  
Unburned Hydrocarbon ◽  
Auto Ignition ◽  
Combustion Duration ◽  
Pilot Fuel ◽  
Dual Fuel Engines ◽  
Rate Of Heat Release

Recently, considerable efforts are made by the engine researches all over the world, focusing primarily on achieving ultra-low emissions of NOx (nitrogen oxides) and soot without any compromise to high thermal efficiency from dual-fuel engine. In this study, combustion performance and engine-out emission of a single cylinder gasoline-diesel dual-fuel engine are numerically investigated by employing a commercial computation fluid dynamics (CFD) software, especially developed for internal combustion engines modeling. Here, gasoline-diesel relative ratio has been varied to find its impacts on performance of a dual-fuel engine. The results show that, in-cylinder pressure, in-cylinder temperature and rate of heat release (ROHR) are increased with gradual increment in diesel relative to gasoline. Injecting higher amount of diesel directly inside the combustion chamber as pilot fuel might have facilitated the auto-ignition process by reducing the ignition delay and accelerated the premixed gasoline-air flame propagation. These led to shorter main combustion duration which is quite desirable to suppress the knock in dual-fuel engines. In addition, NOx emission is found to decrease with relatively higher percentage of diesel. On the other hand, with increasing gasoline ratio relative to diesel, combustion duration is prolonged significantly and led to incomplete combustion, thereby increasing unburned hydrocarbon (UHC) and carbon monoxide (CO).

Influence of Injection Parameters and Operating Conditions on Ignition and Combustion in Dual-Fuel Engines

2018 ◽  
Vol 140 (10) ◽  
Author(s):  
Marcus Grochowina ◽  
Michael Schiffner ◽  
Simon Tartsch ◽  
Thomas Sattelmayer
Keyword(s):  
Natural Gas ◽  
High Speed ◽  
Measurement Techniques ◽  
Injection Pressure ◽  
Operating Conditions ◽  
Liquid Fuels ◽  
Dual Fuel ◽  
Injection Parameters ◽  
Auto Ignition ◽  
Pilot Fuel

Dual-fuel (DF) engines offer great fuel flexibility since they can either run on gaseous or liquid fuels. In the case of diesel pilot-ignited DF engines, the main source of energy is provided by gaseous fuel, whereas the diesel fuel acts only as an ignition source. Therefore, a proper auto-ignition of the pilot fuel is of utmost importance for combustion in DF engines. However, auto-ignition of the pilot fuel suffers from lower compression temperatures of Miller or Atkinson valve timings. These valve timings are applied to increase efficiency and lower nitrogen oxide (NOx) engine emissions. In order to improve the ignition, it is necessary to understand which parameters influence the ignition in DF engines. For this purpose, experiments were conducted and the influence of parameters, such as injection pressure, pilot fuel quantity, compression temperature, and air–fuel (A/F) equivalence ratio of the homogenous natural gas–air mixture were investigated. The experiments were performed on a periodically chargeable combustion cell using optical high-speed recordings and thermodynamic measurement techniques for pressure and temperature. The study reveals that the quality of the diesel pilot ignition in terms of short ignition delay and a high number of ignited sprays significantly depends on the injection parameters and operating conditions. In most cases, the pilot fuel suffers from too high dilution due to its small quantity and long ignition delays. This results in a small number of ignited sprays and consequently leads to longer combustion durations. Furthermore, the experiments confirm that the natural gas of the background mixture influences the auto-ignition of the diesel pilot oil.

Single Cylinder Testing of a High-Pressure Electronic Pilot Fuel Injector for Low NOx Emission Dual Fuel Engines: Part I—Baseline, Feasibility, and Comparative Testing

1990 ◽  
Vol 112 (3) ◽  
pp. 413-421 ◽  
Author(s):  
J. Workman ◽  
G. M. Beshouri
Keyword(s):  
Fuel Injection ◽  
Waste Water Treatment ◽  
Injection System ◽  
Dual Fuel ◽  
Nox Emissions ◽  
Fuel Injector ◽  
Pilot Fuel ◽  
Dual Fuel Engines ◽  
Current Minimum ◽  
Feasibility Test

Current dual fuel engines utilizing standard mechanical (Bosch type) fuel injection systems set to 5–6 percent pilot delivery do not appear capable of reducing NOx emissions much below the current minimum of 4 g/bhp-h without incurring substantial penalties in efficiency and operability. A prototype Electronic Pilot Fuel Injector (EPFI) was designed that overcomes the shortcomings of the mechanical injection system, consistently delivering 3 percent or less pilot at pressures as high as 20,000 psi. The EPFI was installed and tested in one cylinder of a standard production dual fuel engine operating at a waste water treatment facility. A feasibility test confirmed that the engine would indeed operate satisfactorily at 2.9 percent pilot. Comparisons with baseline data revealed the EPFI yielded a 45 percent reduction in NOx emissions with a 3 percent or greater improvement in efficiency. Further optimization of the system, discussed in Part II, indicates that even greater reductions in NOx emissions can be obtained without incurring a penalty in fuel consumption.

scholarly journals Applying detailed chemistry for the dual-fuel engine combustion process simulation using CFD approach

2021 ◽  
Vol 2061 (1) ◽  
pp. 012063
Author(s):  
V N Grinev ◽  
A V Kozlov ◽  
N S Zuev
Keyword(s):  
Experimental Data ◽  
Internal Combustion Engines ◽  
Fuel Efficiency ◽  
Combustion Process ◽  
Propagation Speed ◽  
Fuel Mixture ◽  
Dual Fuel ◽  
Detailed Chemistry ◽  
Pilot Fuel ◽  
Dual Fuel Engines

Abstract Modern research in the area of internal combustion engines is focused on searching and investigating the technologies that will improve fuel efficiency and decrease emissions. The application of dual-fuel engines is considered a potential solution to these problems. In the dual-fuel engine, the natural gas-air mixture is ignited by a small amount of diesel fuel directly injected into a combustion chamber. This paper aims to develop a detailed chemistry mechanism for 3D simulation of the combustion process of a dual-fuel engine, providing sufficient convergence with the experimental data. It should be noted that sufficient convergence must also be provided in terms of such parameters as pilot fuel ignition delay and premixed air-fuel mixture flame propagation speed. In the course of the research, the analysis of the most commonly used detailed chemistry mechanisms for calculation of the combustion process and mechanisms’ disadvantages was performed. The results obtained with the use of the detailed mechanisms were compared with the results obtained without using detailed chemistry and with the experimental data as well.

scholarly journals Experimental investigation of pilot-fuel combustion in dual-fuel engines, Part 1: Thermodynamic analysis of combustion phenomena

Fuel ◽  
2019 ◽  
Vol 255 ◽  
pp. 115642 ◽  
Author(s):  
Aleš Srna ◽  
Beat von Rotz ◽  
Kai Herrmann ◽  
Konstantinos Boulouchos ◽  
Gilles Bruneaux
Keyword(s):  
Experimental Investigation ◽  
Thermodynamic Analysis ◽  
Fuel Combustion ◽  
Dual Fuel ◽  
Pilot Fuel ◽  
Dual Fuel Engines

scholarly journals CFD Study and Experimental Validation of a Dual Fuel Engine: Effect of Engine Speed

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4307
Author(s):  
Roberta De Robbio ◽  
Maria Cristina Cameretti ◽  
Ezio Mancaruso ◽  
Raffaele Tuccillo ◽  
Bianca Maria Vaglieco
Keyword(s):  
Natural Gas ◽  
High Performance ◽  
Engine Speed ◽  
Pollutant Emissions ◽  
Dual Fuel ◽  
Automotive Market ◽  
Light Duty ◽  
Viable Solution ◽  
Dual Fuel Engines ◽  
Gas Ratio

Dual fuel engines induce benefits in terms of pollutant emissions of PM and NOx together with carbon dioxide reduction and being powered by natural gas (mainly methane) characterized by a low C/H ratio. Therefore, using natural gas (NG) in diesel engines can be a viable solution to reevaluate this type of engine and to prevent its disappearance from the automotive market, as it is a well-established technology in both energy and transportation fields. It is characterized by high performance and reliability. Nevertheless, further improvements are needed in terms of the optimization of combustion development, a more efficient oxidation, and a more efficient exploitation of gaseous fuel energy. To this aim, in this work, a CFD numerical methodology is described to simulate the processes that characterize combustion in a light-duty diesel engine in dual fuel mode by analyzing the effects of the changes in engine speed on the interaction between fluid-dynamics and chemistry as well as when the diesel/natural gas ratio changes at constant injected diesel amount. With the aid of experimental data obtained at the engine test bench on an optically accessible research engine, models of a 3D code, i.e., KIVA-3V, were validated. The ability to view images of OH distribution inside the cylinder allowed us to better model the complex combustion phenomenon of two fuels with very different burning characteristics. The numerical results also defined the importance of this free radical that characterizes the areas with the greatest combustion activity.

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