An Investigation of Soot Volume Fraction and Temperature for Natural Gas Laminar Diffusion Flame Established From a Honeycomb Gaseous Burner

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
M. M. Ibrahim ◽  
A. Attia ◽  
A. Emara ◽  
H. A. Moneib

The present work is an experimental investigation that aims at studying the effects of different fuel additives on the soot volume fraction and temperature in a well-defined vertical laminar diffusion flame configuration, and these additives include a diluent (argon) that suppresses the formation of soot and a soot promoter (acetylene) that accelerates and intensifies the soot formation. Three different measuring techniques are employed throughout the whole experimental program, namely, a high-resolution digital camera (up to 3.7 fps) for flame visualization, a bare wire Pt/Pt-13% rhodium fine thermocouple of 15 µm wire diameter for measuring the mean gas temperature inside the flame region and a laser system for measuring the in-flame soot volume fraction. The results indicated that the soot inception zone (deep dark parabolic shape) occurs at the immediate vicinity of the burner. The soot oxidation zone is characterized by high luminosity, and it begins after the fuel is largely consumed. The increased percentages of acetylene in the fuel mixture would lead to extending the length of this zone to ultimately occupy the whole visible flame length, where the luminosity becomes independent of the amount of soot. The temperature within the soot surface growth zone (orange color) continues increasing but at a lower rate that reflects the domination of diffusion combustion mode. Limited partial oxidation may be anticipated within this zone due to the relatively high temperature, which is not high enough to cause luminosity of the soot particles.

2006 ◽  
Vol 178 (5) ◽  
pp. 813-835 ◽  
Author(s):  
GUILLAUME LEGROS ◽  
PIERRE JOULAIN ◽  
JEAN-PIERRE VANTELON ◽  
ANDRES FUENTES ◽  
DENIS BERTHEAU ◽  
...  

1983 ◽  
Vol 19 (5) ◽  
pp. 608-610
Author(s):  
L. E. Makharinskii ◽  
N. A. Khalturinskii ◽  
Al. Al. Berlin ◽  
T. A. Rudakova

2021 ◽  
Author(s):  
Nemanja Ceranic

Soot models have been investigated for several decades and many fundamental models exist that prescribe soot formation in agreement with experiments and theories. However, due to the complex nature of soot formation, not all pathways have been fully characterized. This work has numerically studied the influence that aliphatic based inception models have on soot formation for coflow laminar diffusion flames. CoFlame is the in-house parallelized FORTRAN code that was used to conduct this research. It solves the combustion fluid dynamic conservation equations for a variety of coflow laminar diffusion flames. New soot inception models have been developed for specific aliphatics in conjunction with polycyclic aromatic hydrocarbon based inception. The purpose of these models was not to be completely fundamental in nature, but more so a proof-of-concept in that an aliphatic based mechanism could account for soot formation deficiencies that exist with just PAH based inception. The aliphatic based inception models show potential to enhance predicative capability by increasing the prediction of the soot volume fraction along the centerline without degrading the prediction along the pathline of maximum soot. Additionally, the surface reactivity that was used to achieve these results lied closer in the range of numerically derived optimal values as compared to the surface reactivity that was needed to match peak soot concentrations without the aliphatic based inception models.


2019 ◽  
Vol 21 (16) ◽  
pp. 8282-8294 ◽  
Author(s):  
X. Mercier ◽  
O. Carrivain ◽  
C. Irimiea ◽  
A. Faccinetto ◽  
E. Therssen

Experimental evidence supporting the existence of PAH dimers in the proximity of the soot nucleation region of a methane laminar diffusion flame.


2008 ◽  
Author(s):  
Hongsheng Guo ◽  
Stephanie Trottier ◽  
Matthew R. Johnson ◽  
Gregory J. Smallwood

The sooting propensity of laminar diffusion flames employing ethylene/methane mixture fuel is investigated by numerical simulation. Detailed gas phase chemistry and moments method are used to describe the chemical reaction process and soot particle dynamics, respectively. The numerical model captures the primary features experimentally observed previously. At constant temperatures of air and fuel mixture, both maximum soot volume fraction and soot yield monotonically decrease with increasing the fraction of carbon from methane in the fuel mixture. However, when the temperatures of air and fuel mixture are preheated so that the adiabatic temperatures of all flames are same, the variation of the maximum soot yield becomes higher than what would be expected from a linear combination of the flames of pure ethylene and pure methane, showing a synergistic phenomenon in soot formation. Further analysis of the details of the numerical results suggests that the synergistic phenomenon is caused by the combined effects of the variations in the concentrations of acetylene (C2H2) and methyl radical (CH3). When the fraction of carbon from methane in fuel mixture increases, the concentration of C2H2 monotonically decreases, whereas that of methyl radical increases, resulting in a synergistic phenomenon in the variation of propargyl (C3H3) radical concentration due to the reactions C2H2 + CH3 = PC3H4 + H and PC3H4 + H = C3H3 + H2. This synergistic phenomenon causes a qualitatively similar variation trend in the concentration of pyrene (A4) owing to the reaction paths C3H3 → A1 (benzene) → A2 (naphthalene) → A3 (phenanthrene) → A4. Consequently, the synergistic effect occurs for soot inception and PAH condensation rates, leading to the synergistic phenomenon in soot yield. The similar synergistic phenomenon is not observed in the variation of peak soot volume fraction, since the maximum surface growth rate monotonically decreases, as the fraction of carbon from methane in fuel mixture increases.


1999 ◽  
Vol 117 (1-2) ◽  
pp. 117-139 ◽  
Author(s):  
M SMOOKE ◽  
C MCENALLY ◽  
L PFEFFERLE ◽  
R HALL ◽  
M COLKET

2013 ◽  
Vol 79 (802) ◽  
pp. 1147-1154 ◽  
Author(s):  
Yoshio ZAMA ◽  
Kazunori SHIMIZU ◽  
Masaki TSUKUI ◽  
Tomohiko FURUHATA ◽  
Masataka ARAI

Author(s):  
Bijan Kumar Mandal ◽  
Amitava Sarkar ◽  
Amitava Datta

A numerical investigation of the transient development of flame and soot distributions in a laminar axisymmetric coflowing diffusion flame of methane in air has been carried out considering the air preheating effect. The gas phase conservation equations of mass, momentum, energy, and species concentrations along with the conservation equations of soot mass concentration and number density are solved simultaneously, with appropriate boundary conditions, by an explicit finite difference method. Average soot diameters are then calculated from these results. It is observed that the soot is formed in the flame when the temperature exceeds 1300 K. The contribution of surface growth toward soot formation is more significant compared with that of nucleation. Once the soot particles reach the high temperature oxygen-enriched zone beyond the flame, the soot oxidation becomes important. During the initial period, when soot oxidation is not contributing significantly, some of the soot particles escape into the atmosphere. However, under steady condition the exhaust product gas is nonsooty. Preheating of air increases the soot volume fraction significantly. This is both due to more number of soot particles and the increase in the average diameter. However, preheating of air does not cause a qualitative difference in the development of the soot-laden zone during the flame transient period.


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