Effects of Elevated Pressure on Soot Formation in Laminar Diffusion Flames PDF Download

Author: L. L. McCrain
Publisher:
ISBN:
Category :
Languages : en
Pages :

View

Book Description

Author: Laura Lynne McCrain
Publisher:
ISBN:
Category :
Languages : en
Pages : 69

View

Book Description
Keywords: diffusion flame, high pressure, soot formation.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

View

Book Description
Soot volume fraction (f[subscript sv]) is measured quantitatively in a laminar diffusion flame at elevated pressures up to 25 atmospheres as a function of fuel type in order to gain a better understanding of the effects of pressure on the soot formation process. Methane and ethylene are used as fuels; methane is chosen since it is the simplest hydrocarbon while ethylene represents a larger hydrocarbon with a higher propensity to soot. Soot continues to be of interest because it is a sensitive indicator of the interactions between combustion chemistry and fluid mechanics and a known pollutant. To examine the effects of increased pressure on soot formation, Laser Induced Incandescence (LII) is used to obtain the desired temporally and spatially resolved, instantaneous f[subscript sv] measurements as the pressure is incrementally increased up to 25 atmospheres. The effects of pressure on the physical characteristics of the flame are also observed. A laser light extinction method that accounts for signal trapping and laser attenuation is used for calibration that results in quantitative results. The local peak f[subscript sv] is found to scale with pressure as p[superscript 1.2] for methane and p[superscript 1.7] for ethylene.

Author: Adel Maurice Iskander
Publisher:
ISBN:
Category : Flame
Languages : en
Pages : 440

View

Book Description

Author:
Publisher:
ISBN:
Category : Railroads
Languages : en
Pages : 5

View

Book Description

Author: Chul Han Kim
Publisher:
ISBN:
Category :
Languages : en
Pages : 408

View

Book Description

Author: Marc Robert Joseph Charest
Publisher:
ISBN: 9780494777626
Category :
Languages : en
Pages :

View

Book Description

Author: Decio S. (Decio Santos) Bento
Publisher: Library and Archives Canada = Bibliothèque et Archives Canada
ISBN: 9780494024430
Category : Combustion
Languages : en
Pages : 158

View

Book Description
Laminar axisymmetric propane air diffusion flames were studied at pressures 0.1 to 0.725 MPa (1 to 7.25 atm). To investigate the effect of pressure on soot formation, radially resolved soot temperatures and soot volume fractions were deduced from soot radiation emission scans collected at various pressures using spectral soot emission (SSE). Overall flame stability was quite good as judged by the naked eye. Flame heights varied by 15% and flame axial diameters decreased by 30% over the entire pressure range.Analysis of temperature sensitivity to variations in E lambda(m) revealed that a change in E lambda(m) of +/-20% produced a change in local temperature values of about 75 to 100 K or about 5%.Temperatures decreased and soot concentration increased with increased pressure. More specifically, the peak soot volume fraction showed a power law dependence, fv ∝ Pn where n = 2.0 over the entire pressure range. The maximum integrated soot volume fraction also showed a power law relationship with pressure, f ̄v ∝ Pn where n = 3.4 for 1 ≤ P ≤ 2 atm and n = 1.4 for 2 ≤ P ≤ 7.25 atm. The percentage of fuel carbon converted to soot increased with pressure at a rate, etas ∝ Pn where n = 3.3 and n = 1.1 for 1 ≤ P ≤ 2 atm and 2 ≤ P ≤ 7.25 atm respectively.

Author: Paul Michael Mandatori
Publisher:
ISBN: 9780494160565
Category : Combustion
Languages : en
Pages : 198

View

Book Description
Ethane-air laminar coflow non-smoking diffusion flames have been studied at pressures up to 3.34 MPa to determine the effect of pressure on soot formation, flame temperatures and physical flame properties. The spectral soot emission (SSE) diagnostic was used to obtain spatially resolved (both radially and axially) soot volume fraction and soot temperature measurements at pressures of 0.20 to 3.34 MPa. In general, temperature profiles of a given height were found to decrease with increasing pressure. Pressure was found to enhance soot formation with decreased sensitivity as pressures were increased. A power law relation between maximum soot volume fraction and pressure was found to be fvmax & prop;P 2.39 for 0.20 & le; P & le; 1.52 MPa and fvmax & prop;P 1.10 for 1.52 & le; P & le; 3.34 MPa. The integrated line-of-sight soot volume fraction was found to vary as fvline, max & prop;P 2.32 for 0.20 & le; P & le; 0.51 MPa, fvline, max & prop;P 1.44 for 0.51 & le; P & le; 1.52 MPa and fvline, max & prop;P 0.95 for 1.52 & le; P & le; 3.34 MPa. The variation of maximum carbon conversion to soot, as a percentage of the fuel's carbon, was etas, max & prop; P2.23 for 0.20 & le; P & le; 1.13 MPa, etas, max & prop; P1.12 for 0.51 & le; P & le; 1.52 MPa and etas, max & prop; P0.41 for 1.52 & le; P & le; 3.34 MPa. The maximum value of carbon conversion was found to be eta s, max = 27.61% at P = 3.34 MPa.

Author: Silin Yang
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

View

Book Description
Effects of fuel doping and fuel chemistry on soot formation were studied in laminar diffusion flames at elevated pressures. Soot spectral emission is used to obtain radial temperature, soot volume fraction, and soot yield profiles. This thesis first investigated addition of 0%-40% ethanol in ethylene flames at 3-10 bar. 10% ethanol-doped flames didn't exhibit measurable soot synergy, whereas 20%-40% ethanol displayed lower soot yields. Secondly, 7.5% of benzene, cyclo-hexane and n-hexane was added into methane flames at 1.4-10 bar. Pressure dependence of sooting propensity is lowest for benzene. Thirdly, 3% of m-xylene and n-octane was mixed with methane at 1.4-10 bar. m-Xylene doped methane flames produced highest soot yields but lowest pressure dependency in soot yields. Results indicate that pressure dependence of highly sooting aromatics weakens compared to that of less sooting n-alkanes at high pressures.