scholarly journals Compressed Biogas-Diesel Dual-Fuel Engine Optimization Study for Ultralow Emission

2014 ◽  
Vol 6 ◽  
pp. 571063 ◽  
Author(s):  
Hasan Koten ◽  
Mustafa Yilmaz ◽  
M. Zafer Gul

The aim of this study is to find out the optimum operating conditions in a diesel engine fueled with compressed biogas (CBG) and pilot diesel dual-fuel. One-dimensional (1D) and three-dimensional (3D) computational fluid dynamics (CFD) code and multiobjective optimization code were employed to investigate the influence of CBG-diesel dual-fuel combustion performance and exhaust emissions on a diesel engine. In this paper, 1D engine code and multiobjective optimization code were coupled and evaluated about 15000 cases to define the proper boundary conditions. In addition, selected single diesel fuel (dodecane) and dual-fuel (CBG-diesel) combustion modes were modeled to compare the engine performances and exhaust emission characteristics by using CFD code under various operating conditions. In optimization study, start of pilot diesel fuel injection, CBG-diesel flow rate, and engine speed were optimized and selected cases were compared using CFD code. CBG and diesel fuels were defined as leading reactants using user defined code. The results showed that significantly lower NOx emissions were emitted under dual-fuel operation for all cases compared to single-fuel mode at all engine load conditions.

Author(s):  
Shuonan Xu ◽  
David Anderson ◽  
Mark Hoffman ◽  
Robert Prucka ◽  
Zoran Filipi

Energy security concerns and an abundant supply of natural gas in the USA provide the impetus for engine designers to consider alternative gaseous fuels in the existing engines. The dual-fuel natural-gas diesel engine concept is attractive because of the minimal design changes, the ability to preserve a high compression ratio of the baseline diesel, and the lack of range anxiety. However, the increased complexity of a dual-fuel engine poses challenges, including the knock limit at a high load, the combustion instability at a low load, and the transient response of an engine with directly injected diesel fuel and port fuel injection of compressed natural gas upstream of the intake manifold. Predictive simulations of the complete engine system are an invaluable tool for investigations of these conditions and development of dual-fuel control strategies. This paper presents the development of a phenomenological combustion model of a heavy-duty dual-fuel engine, aided by insights from experimental data. Heat release analysis is carried out first, using the cylinder pressure data acquired with both diesel-only and dual-fuel (diesel and natural gas) combustion over a wide operating range. A diesel injection timing correlation based on the injector solenoid valve pulse widths is developed, enabling the diesel fuel start of injection to be detected without extra sensors on the fuel injection cam. The experimental heat release trends are obtained with a hybrid triple-Wiebe function for both diesel-only operation and dual-fuel operation. The ignition delay period of dual-fuel operation is examined and estimated with a predictive correlation using the concept of a pseudo-diesel equivalence ratio. A four-stage combustion mechanism is discussed, and it is shown that a triple-Wiebe function has the ability to represent all stages of dual-fuel combustion. This creates a critical building block for modeling a heavy-duty dual-fuel turbocharged engine system.


2021 ◽  
Author(s):  
◽  
Luke James Frogley

<p>Rising costs of diesel fuel has led to an increased interest in dual fuel diesel engine conversion, which can offset diesel consumption though the simultaneous combustion of a secondary gaseous fuel. This system offers benefits both environmentally and financially in an increasingly energy-conscious society. Dual fuel engine conversions have previously been fitted to mechanical injection systems, requiring physical modification of the fuel pump. The aim of this work is to develop a novel electronic dual fuel control system that may be installed on any modern diesel engine using common rail fuel injection with solenoid injector valves, eliminating the need for mechanical modification of the diesel fuel system.  The dual fuel electronic control unit developed replaces up to 90 percent of the diesel fuel required with cleaner-burning and cheaper compressed natural gas, providing the same power output with lower greenhouse gas emissions than pure diesel. The dual fuel system developed controls the flow of diesel, gas, air, and engine timing to ensure combustion is optimised to maintain a specific torque at a given speed and demand. During controlled experimental analysis, the dual fuel system exceeded the target substitution rate of 90 precent, with a peak diesel substitution achieved of 97 percent, whilst maintaining the same torque performance of the engine under diesel operation.</p>


Electronics ◽  
2021 ◽  
Vol 10 (18) ◽  
pp. 2285
Author(s):  
Min-Seop Kim ◽  
Ugochukwu Ejike Akpudo ◽  
Jang-Wook Hur

Diesel engine emissions contribute nearly 30% of greenhouse effects and diverse health and environmental problems. Amidst these problems, it is estimated that there will be a 75% increase in energy demand for transportation by 2040, of which diesel fuel constitutes a major source of energy for transportation. Being a major source of air pollution, efforts are currently being made to curb the pollution spread. The use of water-in-diesel (W/D)-emulsified fuels comes as a readily available (and cost-effective) option with other benefits including engine thermal efficiency, reduced costs, and NOx reduction; nonetheless, the inherent effects—power loss, component wear, corrosion, etc. still pose strong concerns. This study investigates the behavior and damage severity of a common rail (CR) diesel fuel injection system using exploratory and statistical methods under different W/D emulsion conditions and engine speeds. Results reveal that the effect of W/D emulsion fuels on engine operating conditions are reflected in the CR, which provides a reliable avenue for condition monitoring. Also, the effect of W/D emulsion on injection system components-piston, nozzle needle, and ball seat–are presented alongside related discussions.


2013 ◽  
Vol 768 ◽  
pp. 206-212 ◽  
Author(s):  
K. Senthil Kumar ◽  
R. Thundil Karuppa Raj

The objective of this study is to investigate the feasibility of two-stage injection on combustion and exhaust emission characteristics in diesel (main fuel) ethanol (pilot fuel) fuelled single cylinder diesel engine. The pressure crank angle and net heat release rate diagrams revealed that increase in the ethanol pilot quantity causes an increase in the ignition delay in the pilot combustion and hence the main combustion due to diesel fuel is slightly influenced by the ethanol pilot fuel. The increase in the pilot injection decreases the NOx considerably. The concentration of soot emissions also decreases with increase in pilot injection. The CO emissions increases with increase in pilot injection and a slight increase in HC emission is observed.


1988 ◽  
Vol 110 (3) ◽  
pp. 361-368 ◽  
Author(s):  
C. P. Bankston ◽  
L. H. Back ◽  
E. Y. Kwack ◽  
A. J. Kelly

An experimental study of electrostatically atomized and dispersed diesel fuel jets has been conducted. A new electrostatic injection technique has been utilized to generate continuous, stable fuel sprays at charge densities of 1.5–2.0 C/m3 of fluid. Model calculations show that such charge densities may enhance spray dispersion under diesel engine conditions. Fuel jets were injected into room temperature air at one atmosphere at flow rates of 0.25–1.0 cm3/s and delivery pressures of 100–400 kPa. Measured mean drop diameters were near 150 μm with 30 percent of the droplets being less than 100 μm in diameter at typical operating conditions. The electrical power required to generate these sprays was less than 10−6 times the chemical energy available from the fuel. The spray characteristics of an actual diesel engine injector were also studied. The results show considerable differences in spray characteristics between the diesel injector and electrostatic injection. Finally, ignition and stable combustion of electrostatically dispersed diesel fuel jets was achieved. The results show that electrostatic fuel injection can be achieved at practical flow rates, and that the characteristics of the jet breakup and dispersion have potential application to combustion systems.


1970 ◽  
Vol 46 (2) ◽  
pp. 195-200 ◽  
Author(s):  
GA Rao ◽  
AVS Raju ◽  
CVM Rao ◽  
KG Rajulu

In the present work, LPG, a by-product of petroleum refining process is used to replace conventional diesel fuel, partially, for improved combustion efficiency and clean burning. A conventional diesel engine was operated on the dual-fuel mode, using LPG as the primary fuel and diesel as the pilot fuel. A four-stroke, single-cylinder diesel engine, most widely used in agricultural sector, has been considered for the purpose of experimentation. The engine was operated at a constant speed of 1500 rpm at a low engine load of 20% and a high engine load of 80%. Under both these operating conditions, combustion, performance and emission characteristics of the engine have been evaluated and compared with that of baseline diesel fuel operation. At 20 % engine load the brake thermal efficiency of the engine has found to decrease with an increase in the LPG content. On the other hand at 80% engine load, it has increased with an increase in the LPG content. Same trend has been observed with regard to the mechanical efficiency. The volumetric efficiency has decreased with an increase in the LPG content at both the loads. The engine operation is more economical on dual-fuel operation at 80% engine load, whereas at 20% engine load, diesel fuel operation is found to be better. With regard to emissions, smoke density and emissions of NOx were found to reduce with an increase in LPG content at both the loads; however, emissions of HC and CO have shown the reverse trend. Key words: Dual-Fuel; LPG; Diesel; Combustion; Performance; Emissions Load. DOI: http://dx.doi.org/10.3329/bjsir.v46i2.8186 Bangladesh J. Sci. Ind. Res. 46(2), 195-200, 2011


2021 ◽  
Author(s):  
◽  
Luke James Frogley

<p>Rising costs of diesel fuel has led to an increased interest in dual fuel diesel engine conversion, which can offset diesel consumption though the simultaneous combustion of a secondary gaseous fuel. This system offers benefits both environmentally and financially in an increasingly energy-conscious society. Dual fuel engine conversions have previously been fitted to mechanical injection systems, requiring physical modification of the fuel pump. The aim of this work is to develop a novel electronic dual fuel control system that may be installed on any modern diesel engine using common rail fuel injection with solenoid injector valves, eliminating the need for mechanical modification of the diesel fuel system.  The dual fuel electronic control unit developed replaces up to 90 percent of the diesel fuel required with cleaner-burning and cheaper compressed natural gas, providing the same power output with lower greenhouse gas emissions than pure diesel. The dual fuel system developed controls the flow of diesel, gas, air, and engine timing to ensure combustion is optimised to maintain a specific torque at a given speed and demand. During controlled experimental analysis, the dual fuel system exceeded the target substitution rate of 90 precent, with a peak diesel substitution achieved of 97 percent, whilst maintaining the same torque performance of the engine under diesel operation.</p>


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