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.

Ability of the Methane Number Index of a Fuel to Predict Rapid Combustion in Heavy Duty Dual Fuel Engines for North American Locomotives

2015 ◽  
Author(s):  
Daniel G. Van Alstine ◽  
David T. Montgomery ◽  
Timothy J. Callahan ◽  
Radu C. Florea
Keyword(s):  
Natural Gas ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Fuel Combustion ◽  
Dual Fuel ◽  
Rapid Combustion ◽  
Dual Fuel Engines ◽  
Dual Fuel Combustion ◽  
Methane Number

Low natural gas prices have made the fuel an attractive alternative to diesel and other common fuels, particularly in applications that consume large quantities of fuel. The North American rail industry is examining the use of locomotives powered by dual fuel engines to realize savings in fuel costs. These dual fuel engines can substitute a large portion of the diesel fuel with natural gas that is premixed with the intake air. Engine knock in traditional premixed spark-ignited combustion is undesirable but well characterized by the Methane Number index, which quantifies the propensity of a gaseous fuel to autoignite after a period of time at high temperature. Originally developed for spark-ignited engines, the ability of the methane number index to predict a fuel’s “knock” behavior in dual fuel combustion is not as fully understood. The objective of this effort is to evaluate the ability of an existing methane number algorithm to predict rapid combustion in a dual fuel engine. Sets of specialized natural gas fuel blends that, according to the MWM methane number algorithm, should have similar knock characteristics are tested in a dual fuel engine and induced to experience rapid combustion. Test results and CFD analysis reveal that rapid or aggressive combustion rates happen late in the dual fuel combustion event with this engine hardware configuration. The transition from normal combustion to late rapid combustion is characterized by changes in the heat release rate profiles. In this study, the transition is also represented by a shift in the crank angle location of the combustion’s peak heat release rate. For fuels of similar methane number that should exhibit similar knock behavior, these transitions occur at significantly different relative air-fuel ratios, demonstrating that the existing MWM methane number algorithm, while excellent for spark-ignited engines, does not fully predict the propensity for rapid combustion to occur in a dual fuel engine within the scope of this study. This indicates that physical and chemical phenomena present in rapid or aggressive dual fuel combustion processes may differ from those in knocking spark-ignited combustion. In its current form a methane number algorithm can be used to conservatively rate dual fuel engines. It is possible that derivation of a new reactivity index that better predicts rapid combustion behavior of the gaseous fuel in dual fuel combustion would allow ratings to be less conservative.

Simplified High Performance Injection Systems for Dual-fuel Engines

2016 ◽  
Vol 6 (3) ◽  
pp. 32-39 ◽  
Author(s):  
Clemens Senghaas ◽  
Michael Willmann ◽  
Hans-Joachim Koch
Keyword(s):  
High Performance ◽  
Dual Fuel ◽  
Dual Fuel Engines

scholarly journals Editorial: Advances in Compression Ignition Natural Gas–Diesel Dual-Fuel Engines

2021 ◽  
Vol 7 ◽  
Author(s):  
Hongsheng Guo ◽  
Hailin Li ◽  
Lino Guzzella ◽  
Masahiro Shioji
Keyword(s):  
Natural Gas ◽  
Dual Fuel ◽  
Compression Ignition ◽  
Dual Fuel Engines

scholarly journals THERMODYNAMIC ANALYSIS OF ELECTRIC POWER PRODUCTION TECHNOLOGIES IN COGENERATION SYSTEMS ON FPSO AIMING TO REDUCE CO2 EMISSIONS

2021 ◽  
Vol 20 (1) ◽  
pp. 58
Author(s):  
A. G. Gallego ◽  
A. C. C. Souza ◽  
P. H. Morais ◽  
M. Modesto
Keyword(s):  
Natural Gas ◽  
Thermodynamic Analysis ◽  
Gas Turbines ◽  
Maximum Load ◽  
Dual Fuel ◽  
Complex Structures ◽  
Oil Platforms ◽  
Electric Power Production ◽  
Dual Fuel Engines ◽  
Production Technologies

Oil platforms are complex structures used to host workers and equipmentneeded in offshore exploration. This study focuses on the platform's heatand electricity cogeneration plant, which supplies a process heat exchangersnet, and provides the necessary electricity for all the equipment used for theprocess and worker's accommodation in the platform. The platform demandwith maximum load is 75 MW, which could be achieved using four gasturbines (25 MW each), one of which is kept for backup purposes or usingsix dual-fuel engines diesel/natural gas (15 MW each), one of which is alsokept for backup purposes. Therefore, the thermodynamic analysis wasperformed - considering five specific demand points of the platform -comparing the two traditional configurations (gas turbines and dual-fuelengines diesel/natural gas) and a combined configuration. The combinedconfiguration is composed of three gas turbines and two dual-fuel enginesdiesel/natural gas (one of the gas turbines kept for backup purposes). Theconfigurations presented respectively 35.5%, 48.4% and 42.6% at highestoverall efficiency; 611.34 g/kWh, 373.45 g/kWh, 472.74 g/kWh at lowestCO2 emissions considering full attendance of electrical and thermaldemands. The configurations using only gas turbines and the combinedfully attended the thermal demand of the platform without using auxiliarypieces of equipment. Therefore, it was possible to observe that thecombined configuration presented several advantages concerning isolatedsystems, proving to be an excellent option for sustainable energygeneration, reducing emissions of polluting gases and greater flexibility ofits operation concerning to configuration only with turbines, and physicaloccupation in relation to configuration only with engines.

scholarly journals A Numerical Study on the Pilot Injection Conditions of a Marine 2-Stroke Lean-Burn Dual Fuel Engine

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1396
Author(s):  
Hao Guo ◽  
Song Zhou ◽  
Jiaxuan Zou ◽  
Majed Shreka
Keyword(s):  
Natural Gas ◽  
Fuel Injection ◽  
Numerical Study ◽  
Pollutant Emissions ◽  
Dual Fuel ◽  
Injection Timing ◽  
Pilot Injection ◽  
Lean Burn ◽  
Injection Duration ◽  
Pilot Fuel

The global demand for clean fuels is increasing in order to meet the requirements of the International Maritime Organization (IMO) of 0.5% global Sulphur cap and Tier III emission limits. Natural gas has begun to be popularized on liquefied natural gas (LNG) ships because of its low cost and environment friendly. In large-bore marine engines, ignition with pilot fuel in the prechamber is a good way to reduce combustion variability and extend the lean-burn limit. However, the occurrence of knock limits the increase in power. Therefore, this paper investigates the effect of pilot fuel injection conditions on performance and knocking of a marine 2-stroke low-pressure dual-fuel (LP-DF) engine. The engine simulations were performed under different pilot fuel parameters. The results showed that the average in-cylinder temperature, the average in-cylinder pressure, and the NOx emissions gradually decreased with the delay of the pilot injection timing. Furthermore, the combustion situation gradually deteriorated as the pilot injection duration increased. A shorter pilot injection duration was beneficial to reduce NOx pollutant emissions. Moreover, the number of pilot injector orifices affected the ignition of pilot fuel and the flame propagation speed inside the combustion chamber.

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