scholarly journals Numerical Investigation on the Effect of the Oxymethylene Ether-3 (OME3) Blending Ratio in Premixed Sooting Ethylene Flames

2021 ◽  
Vol 7 ◽  
Author(s):  
Robert Schmitz ◽  
Mariano Sirignano ◽  
Christian Hasse ◽  
Federica Ferraro
Keyword(s):  
Fossil Fuels ◽  
Soot Particle ◽  
Volume Fraction ◽  
Soot Volume Fraction ◽  
Synthetic Fuels ◽  
Entropy Maximization ◽  
Physico Chemical ◽  
Soot Precursor ◽  
Flame Condition ◽  
Oxygenated Fuels

Synthetic fuels, especially oxygenated fuels, which can be used as blending components, make it possible to modify the emission properties of conventional fossil fuels. Among oxygenated fuels, one promising candidate is oxymethylene ether-3 (OME3). In this work, the sooting propensity of ethylene (C2H4) blended with OME3 is numerically investigated on a series of laminar burner-stabilized premixed flames with increasing amounts of OME3, from pure ethylene to pure OME3. The numerical analysis is performed using the Conditional Quadrature Method of Moments combined with a detailed physico-chemical soot model. Two different equivalence ratios corresponding to a lightly and a highly sooting flame condition have been investigated. The study examines how different blending ratios of the two fuels affect soot particle formation and a correlation between OME3 blending ratio and corresponding soot reduction is established. The soot precursor species in the gas-phase are analyzed along with the soot volume fraction of small nanoparticles and large aggregates. Furthermore, the influence of the OME3 blending on the particle size distribution is studied applying the entropy maximization concept. The effect of increasing amounts of OME3 is found to be different for soot nanoparticles and larger aggregates. While OME3 blending significantly reduces the amount of larger aggregates, only large amounts of OME3, close to pure OME3, lead to a considerable suppression of nanoparticles formed throughout the flame. A linear correlation is identified between the OME3 content in the fuel and the reduction in the soot volume fraction of larger aggregates, while smaller blending ratios may lead to an increased number of nanoparticles for some positions in the flame for the richer flame condition.

A Numerical and Experimental Study of Soot Precursor and Primary Particle Size of N-Butylbenzene in Laminar Flame

2021 ◽  
Author(s):  
Mingshan Sun ◽  
Zhiwen Gan
Keyword(s):  
Soot Particle ◽  
Primary Particle ◽  
Volume Fraction ◽  
Soot Formation ◽  
Laminar Flame ◽  
Particle Diameter ◽  
Soot Volume Fraction ◽  
The Core ◽  
Soot Precursor ◽  
Combined Mechanism

Abstract The current study analyzed the soot precursor of the n-butylbenzene found in diesel and kerosene in laminar flame, and integrated the corresponding poly-aromatic hydrocarbon (PAH) growth mechanism with the popular n-butylbenzene oxidation mechanisms to improve the soot formation prediction of n-butylbenzene. The size of soot precursor was determined by the fringe length in the core of soot particle since the nanostructure of the core of soot particle is similar with that of nascent soot particle formed by soot precursor nucleation. The geometric mean fringe length in core of soot particles was measured to be 0.67 nm approximating to the size of five-ringed PAH (A5). An A5 growth mechanism was added on a popular n-butylbenzene mechanism, and the combined mechanism was further reduced. After validation by the ignition delay time in literature, the combined mechanism was then validated by the primary particle diameter in laboratory and soot volume fraction of n-propylbenzene in literature. The calculated soot precursor concentration and PAH condensation rate of the combined mechanism are smaller than that of the base mechanism. The simulated primary soot particle diameter of proposed combined mechanism agrees well with the measure primary soot particle diameter. Comparing to the simulated soot volume fraction of base n-butylbenzene mechanism, the simulated soot volume fraction of proposed combined n-butylbenzene-A5 mechanism agrees well with the measure soot volume fraction of n-propylbenzene in literature. This study provides certain support for further investigation of soot formation of n-butylbenzene and its relative fuel like diesel and kerosene.

A Numerical Study on the Influence of Hydrogen Addition on Soot Formation in a Laminar Aviation Kerosene (Jet A1) Flame at Elevated Pressure

2021 ◽  
Author(s):  
Mingshan Sun ◽  
Zhiwen Gan
Keyword(s):  
Volume Fraction ◽  
Soot Formation ◽  
Laminar Flame ◽  
Numerical Study ◽  
Soot Volume Fraction ◽  
Elevated Pressure ◽  
Condensation Process ◽  
Hydrogen Addition ◽  
Aviation Kerosene ◽  
Soot Precursor

Abstract The hydrogen addition is a potential way to reduce the soot emission of aviation kerosene. The current study analyzed the effect of hydrogen addition on aviation kerosene (Jet A1) soot formation in a laminar flame at elevated pressure to obtain a fundamental understanding of the reduced soot formation by hydrogen addition. The soot formation of flame was simulated by CoFlame code. The soot formation of kerosene-nitrogen-air, (kerosene + replaced hydrogen addition)-nitrogen-air, (kerosene + direct hydrogen addition)-nitrogen-air and (kerosene + direct nitrogen addition)-nitrogen-air laminar flames were simulated. The calculated pressure includes 1, 2 and 5 atm. The hydrogen addition increases the peak temperature of Jet A1 flame and extends the height of flame. The hydrogen addition suppresses the soot precursor formation of Jet A1 by physical dilution effect and chemical inhibition effect, which weaken the poly-aromatic hydrocarbon (PAH) condensation process and reduce the soot formation. The elevated pressure significantly accelerates the soot precursor formation and increases the soot formation in flame. Meanwhile, the ratio of reduced soot volume fraction to base soot volume fraction by hydrogen addition decreases with the increase of pressure, indicating that the elevated pressure weakens the suppression effect of hydrogen addition on soot formation in Jet A1 flame.

Fischer-Tropsch Fuel Characterization via Microturbine Testing and Fundamental Combustion Measurements

2008 ◽  
Author(s):  
A. Srinivasan ◽  
B. Ellis ◽  
J. F. Crittenden ◽  
W. E. Lear ◽  
Brandon Rotavera ◽  
...  
Keyword(s):  
Shock Tube ◽  
Volume Fraction ◽  
Soot Formation ◽  
Soot Volume Fraction ◽  
Jet Fuels ◽  
Synthetic Fuels ◽  
Fischer Tropsch ◽  
Ignition Delay Times ◽  
Test Region ◽  
Fuel Characterization

Synthetic fuels such as Fischer-Tropsch (FT) fuels are of interest as a replacement for aviation, diesel, and other petroleum-based fuels, and the present paper outlines a joint program to study the combustion behavior of FT synthetic fuels. To this end, shock-tube spray and high-recirculation combustion rig experiments are being utilized to study the ignition delay times, formation of soot, and emissions of FT jet fuels. Undiluted shock tube spray experiments were conducted using a recently developed heterogeneous technique wherein the fuel is sprayed directly into the test region of a shock tube. The high recirculation combustion rig is a complete gas turbine system where Syntroleum FT jet fuel was combusted, and soot formation and emission characteristics were observed. Reduction of soot volume fraction and unchanged emissions were observed, in agreement with previous investigations. The fundamental shock tube results were found to be consistent with the observations made in the experimental engine.

In-Situ Soot Measurements in an Operating Engine Gas Turbine Combustor

1991 ◽  
Author(s):  
R. Koch ◽  
S. Wittig ◽  
H.-J. Feld ◽  
H.-J. Mohr
Keyword(s):  
Gas Turbine ◽  
Soot Particle ◽  
Volume Fraction ◽  
Particle Diameter ◽  
Soot Volume Fraction ◽  
Light Extinction ◽  
Gas Turbine Combustor ◽  
Rotating Speed ◽  
Secondary Zone

The dispersion quotient method, an optical measuring technique for particles, has been applied to in situ measurements of the soot particle size and density in the secondary zone of a KHD GT-216 gas turbine combustor under operating engine conditions. The optical technique, which has been developed at the Institut of Thermische Strömungsmaschinen, is based on the light extinction at different wavelength by a particle cloud due to absorption and scattering. It is of particular advantage in applications, where particles of small size (d ≤ 1.0μ) and high density are to be investigated. In the present investigation, two idling running conditions of the turbine have been studied: 30.000 rpm and 47.000 rpm. The results show, that the dispersion quotient method is well suited for soot measurements in pressurized flames. In particular, it was found, that the soot particle diameter is not effected by the rotating speed of the turbine. The size of the soot particles was always in the range from 0.1 to 0.3 mircon. The soot volume fraction, however, was found to be strongly influenced by different rotating speeds, with higher rotating speed causing higher volume fraction of soot.

A Soot Chemistry Model That Captures Fuel Effects

2014 ◽  
Author(s):  
Karthik V. Puduppakkam ◽  
Abhijit U. Modak ◽  
Chitralkumar V. Naik ◽  
Joaquin Camacho ◽  
Hai Wang ◽  
...  
Keyword(s):  
Particle Size ◽  
Soot Particle ◽  
Volume Fraction ◽  
Soot Volume Fraction ◽  
Surface Model ◽  
Particle Nucleation ◽  
Size Distributions ◽  
Surface Kinetics ◽  
Particle Size Distributions ◽  
Detailed Chemistry

A detailed chemistry model is necessary to simulate the effects of variations in fuel composition on soot emissions. In this work, we have developed a detailed chemistry model for the soot formation and oxidation chemistry, with a focus on the surface kinetics of the soot-particle. The model has been compared to a unique set of soot particle-size data measured in flames for several single-component fuels. Fuel components used in the experiments represent the chemical classes found in jet, gasoline, and diesel fuels, including n-heptane (representative of n-alkanes) and toluene (aromatic). Measurements were taken in burner-stabilized stagnation-flame (BSSF) experiments, which can be simulated well using the 1-dimensional BSSF flame model in CHEMKIN-PRO. Soot volume fraction and particle size distributions are modeled using the sectional method option for Particle Tracking, within CHEMKIN-PRO software. The well-characterized flow of the BSSF experiments allows the modeling to focus on the kinetics. Validated detailed reaction mechanisms for fuel combustion and PAH production, combined with the new soot surface-kinetics mechanism, were used in the simulations. Simulation results were compared to measurements for both particle size distributions and total soot volume fraction. Observed effects of fuel, temperature, pressure, equivalence ratio and residence time on the soot size distribution shape and soot quantity were reproduced by the model. The chemistry in the soot surface model includes particle nucleation, growth through the HACA (hydrogen-abstraction/carbon-addition) and PAH-condensation (polycyclic aromatic hydrocarbons) pathways, as well as soot-oxidation pathways. In addition to soot chemistry, the physics of particle coagulation and aggregation were included in the model. The results demonstrate the ability of well-validated chemistry to predict both dramatic and subtle effects related to soot mass and soot particle size.

Soot Particle Measurements in Steady and Unsteady Laminar Diffusion Flames Using Laser-Induced Incandescence

2003 ◽  
Author(s):  
H. Sapmaz ◽  
C. X. Lin ◽  
M. A. Ebadian ◽  
C. Ghenai
Keyword(s):  
Soot Particle ◽  
Volume Fraction ◽  
Diffusion Flames ◽  
Soot Volume Fraction ◽  
Pulsation Period ◽  
Laminar Diffusion Flames ◽  
Fuel Flow ◽  
Laser Induced Incandescence ◽  
Sequential Images ◽  
Good Agreement

Laser-Induced Incandescence (LII) is used in this study to measure the soot volume fraction for steady and unsteady laminar ethylene diffusion flames. For the steady flame the soot profiles obtained in this study using LII showed good agreement with those obtained previously using scattering/extinction technique. For the unsteady or flickering flames, we generated very repeatable time-varying diffusion flames by forcing the fuel flow at frequencies between 1–10 Hz. Phase lock images of the soot volume fractions were obtained for different phases between 0° and 360°. The sequential images showed the dynamics of the interactions between the generated vortices in the fuel and the flame. The phase-locked soot images revealed the entire motion process of the soot field during each pulsation period. The results obtained in the course of this study show that the soot emission decreased by lowering the oscillation frequency of the flame.

Extraction and Determination of Physico-chemical Properties of Oil from Watermelon Seeds (Citrullus lanatus L) to Use in Internal Combustion Engines

2017 ◽  
Vol 68 (11) ◽  
pp. 2676-2681
Author(s):  
Mihaela Gabriela Dumitru ◽  
Dragos Tutunea
Keyword(s):  
Fatty Acid ◽  
Internal Combustion Engines ◽  
Fossil Fuels ◽  
Citrullus Lanatus ◽  
Combustion Process ◽  
Chemical Properties ◽  
Physico Chemical ◽  
Mean Diameter ◽  
Geometrical Mean ◽  
Reduction Of Nox

The purpose of this work was to investigate the physicochemical properties of watermelon seeds and oil and to find out if this oil is suitable and compatible with diesel engines. The results showed that the watermelon seeds had the maximum length (9.08 mm), width (5.71mm), thickness (2.0 mm), arithmetic mean diameter (5.59 mm), geometrical mean diameter (4.69 mm), sphericity (51.6%), surface area (69.07), volume 0.17 cm3 and moisture content 5.4%. The oil was liquid at room temperature, with a density and refractive index of 0.945 and 1.4731 respectively acidity value (1.9 mgNaOH/g), free fatty acid (0.95 mgNaOH), iodine value (120 mgI2/100g), saponification value (180 mgKOH/g), antiradical activity (46%), peroxide value (7.5 mEqO2/Kg), induction period (6.2 h), fatty acid: palmitic acid (13.1%), stearic acid (9.5 %), oleic acid (15.2 %) and linoleic acid (61.3%). Straight non food vegetable oils can offer a solution to fossil fuels by a cleaner burning with minimal adaptation of the engine. A single cylinder air cooled diesel engine Ruggerini RY 50 was used to measure emissions of various blends of watermelon oil (WO) and diesel fuel (WO10D90, WO20D80, WO30D70 and WO75D25). The physic-chemical properties of the oil influence the combustion process and emissions leading to the reduction of NOX and the increase in CO, CO2 and HC.

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