Computation and measurement for distributions of temperature and soot volume fraction in diffusion flames

Abstract

A combined computational and experimental investigation to examine temperature and soot volume fraction in coflow ethylene-air diffusion flames was presented. A numerical simulation was conducted by using a relatively detailed gas-phase chemistry and complex thermal and transport properties coupled with a semi-empirical two-equation soot model. Thermal radiation was calculated using the discrete ordinates method. An image processing technique and a decoupled reconstruction method were used to simultaneously measure the distributions of temperature and soot volume fraction. The results show that the maximum error for temperature does not exceed 10% between the prediction and the measurement. And the maximum error is 6.9% for soot volume fraction between prediction and measurement. Additional simulations were performed to explore the effects of global equivalence ratio on diffusion flames and the soot formation. The results display that the soot formation increases with decreasing the coflow air velocity. And the soot formation in each case appears in the annular region, where the temperature ranges from about 1 000 K to 2 000 K and the profile becomes taller and wider when the coflow air is decreased.

Keywords

temperature / soot volume fraction / simulation / measurement / diffusion flame

References

[1] SnellingD. R., ThomsonK. A., SmallwoodG. J., Gülderö. L., WeckmanE. J., FraserR. A.. spectrally resolved measurement of flame radiation to determine soot temperature and concentration [J]. AIAA Journal, 2002, 40(9): 1789-1795

[2] LiuL. H., ManG. L.. Reconstruction of time-averaged temperature of non-axisymmetric turbulent unconfined sooting flame by inverse radiation analysis [J]. Journal of Quantitative Spectroscopy & Radiative Transfer, 2003, 78(2): 139-149

[3] De IuliisS., BarbiniM., BenecchiS., CignoliF., ZizakG.. Determination of the soot volume fraction in an ethylene diffusion flame by multiwavelength analysis of soot radiation [J]. Combustion and Flame, 1998, 115(1/2): 253-261

[4] HuandY., YanY.. Transient two-dimensional temperature measurement of open flames by dual-spectral image analysis [J]. IEEE Transactions of the Institute of Measurement and Control, 2000, 22(5): 371-384

[5] LouC., ZhouH.-chun.. Deduction of the two-dimensional distribution of temperature in a cross section of a boiler furnace from images of flame radiation [J]. Combustion and Flame, 2005, 143(1/2): 97-105

[6] ZhouH.-c., HanS.-d., ShengF., ZhengC.-guang.. Visualization of three-dimensional temperature distributions in a large-scale furnace via regularized reconstruction from radiative energy images: Numerical studies [J]. Journal of Quantitative Spectroscopy & Radiative Transfer, 2002, 72(4): 361-383

[7] LouC., ChenC., SunY.-p., ZhouH.-chun.. Review of soot measurement in hydrocarbon-air flame [J]. Science China Technological Sciences, 2010, 53: 2129-2141

[8] AiY.-h., ZhouH.-chun.. Simulation on simultaneous estimation of non-uniform temperature and soot volume fraction distributions in axisymmetric sooting flames [J]. Journal of Quantitative Spectroscopy & Radiative Transfer, 2005, 91(1): 11-26

[9] ConnellyB. C., LongM. B., SmookeM. D., HallR. J., ColketM. B.. Computational and experimental investigation of the interaction of soot and NO in coflow diffusion flames [J]. Proceedings of the Combustion Institute, 2009, 32(1): 777-784

[10] LiuF., GuoH., SmallwoodG. J., GulderÖ L. L.. Effects of gas and soot radiation on soot formation in a two-dimensional laminar ethylene-air diffusion flame [J]. Journal of Quantitative Spectroscopy Radiative Transfer, 2002, 73(2/3/4/5): 409-421

[11] LiuF., GuoH., SmallwoodG. J., GulderÖ L. L.. Numerical modelling of soot formation and oxidation in laminar coflow non-smoking and smoking ethylene diffusion flames [J]. Combustion of Theory Modeling, 2003, 7(3): 301-315

[12] GuoH., LiuF., SmallwoodG. J., GulderÖ L. L.. Numerical study on the influence of hydrogen addition on soot formation in a laminar ethylene-air diffusion flame [J]. Combustion and Flame, 2006, 145(1/2): 324-338

[13] ZhangY.-d., ZhouH.-c., XieM.-l., FangQ.-y., WeiYan.. Modeling of soot formation in gas burner using reduced chemical kinetics coupled with CFD code [J]. Chinese Journal of Chemical Engineering, 2010, 18(6): 142-154

[14] KeeR. J., WarnatzJ., MillerJ. A.A fortran computer program package for the evaluation of gas Phase viscosities, conductivities, and diffusion coefficients [R], 1983, Albuquerque, New Mexico, Sandia National Laboratories

[15] LeungK. M., LindstedtR. P., JonesW. P.. A simplified reaction mechanism for soot formation in nonpremixed flames [J]. Combustion and Flame, 1991, 87(3/4): 289-305

[16] TrueloveJ. S.Evaluation of a multi-flux model for radiative heat transfer in cylindrical furnaces, 1978, Harwell, UK, AERE

[17] ThurgoodC. P., PollardA., BeckerH. A.. The TN quadrature set for the discrete ordinates method [J]. Journal of Heat Transfer, 1995, 117: 1068-1070

[18] BuckiusR. O., TienC. L.. Infrared flame radiation. International Journal Heat and Mass Transfer, 1977, 20: 93-106

[19] LiuF., SmallwoodG. J., GulderO. L.. Application of the statistical narrow-band correlated-K method to low-resolution spectral intensity and radiative heat transfer calculations-effects of the quadrature scheme [J]. International Journal Heat Mass Transfer, 2000, 43: 3119-3135

[20] SMITH G P, GOLDEN D M, FRENKLACH M, MORIARTY N W, Eiteneer B, GOLDENBERG M, BOWMAN C T, HANSON R K, SONG S, GARDINER J, W C, LISSIANSKI V V, QIN Z. GRI-Mech, version 3.0 [EB/OL]. http://www.me.berkeley.edu/gri mech/, 2000.

[21] ZhouH.-c., HanS.-d., LouC., LiuHao.. A New model of radiative image formation used in visualization of 3-D temperature distributions in large-scale furnaces [J]. Numerical Heat Transfer: Fundamental, 2002, 42(3): 243-258

[22] SmookeM. D., McenallyC. S., PfefferleL. D., HallR. J., ColketM. B.. Computational and experimental study of soot formation in a coflow, laminar diffusion flame [J]. Combustion and Flame, 1999, 117(1/2): 117-139

[23] ZhangJ., ZhangM. C., YuJ.. Extended application of the moving flame front model for combustion of a carbon particle with a finite-rate homogenous reaction [J]. Energy & Fuels, 2010, 24(2): 871-879