Soot formation in a laminar ethylene/air diffusion flame at pressures from 1 to 8 atm

Abstract

/npsi/ctrl?lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?lang=fr Access and use of this website and the material on it are subject to the Terms and Conditions set forth at http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en NRC Publications Archive Archives des publications du CNRCFor the publisher's version, please access the DOI link below./ Pour consulter la version de l'éditeur, utilisez le lien DOI ci-dessous.http://dx.doi.org/10. 1016/j.proci.2012.07.006 Proceedings of the Combustion Institute, 34, 1, pp. 1795Institute, 34, 1, pp. -1802Institute, 34, 1, pp. , 2012 Soot formation in a laminar ethylene/air diffusion flame at pressures from 1 to 8atm Guo, Hongsheng; Gu, Zhongzhu; Thomson, Kevin A.; Smallwood, Gregory J.; Baksh, Fazil F. We affirm that we shall pay the color reproduction charges if applicable.2 AbstractThe effect of pressure on soot formation in a laminar ethylene/air coflow diffusion flame was investigated by experiments and numerical simulation at pressures from 1 to 8 atm. Soot volume fraction was measured by the diffuse-light two-dimensional line-of-sight attenuation optical diagnostic method and calculated by moments model and a relatively detailed gas phase chemistry. The numerical model successfully captured the variation of soot volume fraction with increasing pressure. The detailed analysis of numerical simulation results suggests that although the rates of all soot formation sub-processes increase with increasing pressure, the rates of increase of these sub-processes differ, with that of PAH condensation being the fastest, followed by those of inception and acetylene addition, respectively. At atmosphere pressure, acetylene addition contributes most to soot formation in terms of the overall formed soot mass, while the contribution of PAH condensation significantly increases at high pressures. The variation in the soot formation mechanism is due to the different increase rates of the mole concentrations and formation of several key species that significantly affect soot inception, acetylene addition and PAH condensation.

Numerical and experimental study of the influence of CO2 and N2 dilution on soot formation in laminar coflow C2H4/air diffusion flames at pressures between 5 and 20 atm

“…It is noted that the peak mole fractions of C 2 H 2 and A 4 shown in Table 5 are the values with their consumption to form soot accounted for. Such coupling has a relatively small influence on the C 2 H 2 concentrations, but has a very large impact on the A 4 concentrations [49]. The decrease and increase of the peak C 2 H 2 and A 1 mole fractions with increasing pressure, respectively, are consistent with the experimental measurements of Abhinavam Kailasanathan et al [21,22].…”

“…The chemical effect of pressure on diffusion flame and soot formation has received little attention, though such effect has been recognized by Liu et al [44] and more recently discussed by Mandatori and Gülder [48]. The chemical effect of pressure on soot formation has been demonstrated in a recent numerical study of Guo et al [49], who showed that the relative importance of benzene forming reactions to benzene and the contributions of inception, HACA, and PAH condensation to soot loading varies as the pressure increases from 1 to 8 atm in a laminar coflow undiluted C 2 H 4 /air diffusion flame.…”

“…Variation of the calculated total soot loadings in the CO 2 -and FCO 2 -diuted flames and the percentage reduction in the total soot loading and the peak soot volume fraction between the two flames with pressure. processes [44,49]. It is therefore expected that pressure can significantly influence the chemical effect of CO 2 on the flame structure (temperature and species concentrations) and soot production, since at elevated pressures the mole fractions of the most important radicals in combustion (O, H, and OH) can be substantially lowered through enhanced three-body recombination reactions.…”

On thermodynamic equilibrium of carbon deposition from gaseous C-H-O mixtures: updating for nanotubes

“…On the other hand, the nucleation of graphite over a catalyst is extremely sensitive to its nanostructure (Bengaard et al 2002). The deposition usually occurs on solid surfaces, but nuclei of solid carbon may also form in the fluid phase (Guo et al 2013, Lemaire et al 2013.…”

Soot modeling of counterflow diffusion flames of ethylene-based binary mixture fuels

“…Soot surface growth is mainly through surface HACA mechanism and the particle dynamics has been modeled by the method of moments [27,28]. These models were pioneered by Frenklach and Wang [8] and later used extensively on various types of flames such as laminar premixed flames [7,[29][30][31][32], laminar counterflow diffusion flames [33][34][35], axis-symmetric coflow diffusion flames [36], 2D non-premixed turbulent flames [37] and 3D flames in diesel engine combustion [38]. The discrete sectional method was also frequently used [39][40][41][42][43][44][45][46] for particle dynamics, especially focused on soot size distribution.…”