|
|
|
Experimental analysis of the effect of oxygen concentration on
soot formation in ethylene diffusion flame |
| LIANG Jun-hui, HUANG Qun-xing, FENG Yu-xiao, CHI Yong, YAN Jian-hua |
| State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China |
|
|
|
Abstract In order to evaluate the effect of oxygen concentration on soot formatting and agglomerating in oxygen-lean and-rich C2H4/ O2/ N2 diffusion flame, the diameter of individual particle and mean size of soot agglomerates sampled by thermophoretic method were estimated from transmission electron microscopy (TEM) images. The volume fraction profiles along vertical and radial directions were measured by laser extinction method. Results show that, for diffusion flame, with increased oxygen concentration, soot particle diameter and mean size of agglomerates at the same vertical position will increase and the vertical location of the peak value of soot volume fraction will shift towards flame bottom. The radial distribution of soot volume fraction becomes narrow and peak values near the flame edge increase quickly. For the flame discussed in this paper, soot formation is enhanced with enriched oxygen concentration. The results can be used for small particle pollutants control from combustion.
|
|
Published: 23 September 2012
|
|
|
氧体积分数对乙烯扩散火焰中烟黑生成影响的实验
为了研究氧体积分数对扩散火焰中烟黑颗粒生长和聚合特性的影响,采用热泳沉积取样结合透射电子显微镜(TEM)图像,分析富氧和贫氧环境下乙烯/O2/N2扩散火焰中烟黑颗粒的粒径和颗粒凝聚体平均颗粒数,并采用激光消光法同步测量烟黑颗粒在火焰轴向和径向的体积分数分布.实验结果表明：对于乙烯扩散火焰,氧体积分数的增加,使火焰中心同一高度上的烟黑粒径和凝聚体平均颗粒数增大,进而引起烟黑体积分数增大,峰值位置前移；在火焰径向方向烟黑颗粒分布向中心收缩,边缘位置烟黑体积分数增大.对于本文讨论的扩散火焰,氧体积分数的增加对烟黑的生成具有促进作用,这对于火焰颗粒污染物的控制研究具有参考意义.
|
|
| ［1］ GLASSMAN I. Soot formation in combustion processes ［C］∥ Twentysecond Symposium (International) on Combustion. Pittsburgh: Combustion Institute, 1989: 295-311.
［2］ HUANG H, BUEKENS A. On the mechanisms of dioxin formation in combustion processes［J］. Chemosphere, 1995, 31(9): 4099-4117.
［3］ SOLOMON S, QIN D, MANNING M, et al. Climate change 2007: The physical science basis［M］. London: Cambridge University Press, 2007: 1-21.
［4］ MANSUROV Z A. Soot formation in combustion processes (Review)［J］. Combustion, Explosion, and Shock Waves, 2005, 41(6): 727-744.
［5］ CHOI M Y, MULHOLLAND G W, HAMINS A, et al. Comparisons of the soot volume fraction using gravimetric and light extinction techniques［J］. Combustion and Flame, 1995, 102(1/2): 161-169.
［6］ MEGARIDIS C M, GRIFFIN D W, KONSUR B. Sootfield structure in laminar sootemitting microgravity nonpremixed flames ［C］∥ Twentysixth Symposium (International) on Combustion. Pittsburgh: Combustion Institute, 1996: 1291-1299.
［7］ LEE KO, MEGARIDIS C M, ZELEPOUGA S, et al. Soot formation effects of oxygen concentration in the oxidizer stream of laminar coannular nonpremixed methane/ air flames ［J］. Combustion and Flame, 2000, 121(1/2): 323-333.
［8］ SHIM S H, SHIN H D. Transition morphology of deposits on SiC fibers in propane/ air laminar diffusion flames［J］. Combustion and Flame, 2002, 131(1/2): 210-218.
［9］ SHIM S H, AHN K Y, JEONG S H, et al. Study of deposit morphology in a propane diffusionflame under fuelrich conditions ［J］. Applied Energy, 2004, 79(2): 179-189.
［10］ WANG Y, NATHAN G J, ALWAHABI Z T, et al. Effect of a uniform electric field on soot in laminar premixed ethylene/ air flames ［J］. Combustion and Flame, 2010, 157(7): 1308-1315.
［11］ JOO H I, GLDER L. Soot formation and temperature structure in small methaneoxygen diffusion flames at subcritical and supercritical pressures ［J］. Combustion and Flame, 2010, 157(6): 1194-1201.
［12］ HU B, YANG B, KOYLU U O. Soot measurements at the axis of an ethylene/ air nonpremixed turbulent jet flame ［J］. Combustion and Flame, 2003, 134(1/2): 93-106.
［13］ ZHU J, CHOI M Y, MULHOLLAND G W, et al. Measurement of visible and nearinfrared optical properties of soot produced from laminar flames［C］∥ Twentyninth Symposium (International) on Combustion. Pittsburgh: Combustion Institute, 2002: 2367-2374.
［14］ KOYLU U O, FAETH G M. Optical properties of overfire soot in buoyant turbulent diffusion flames at long residence times ［J］. Journal of Heat Transfer, 1994, 116(1): 152-159.
［15］ ARANA C P, PONTONI M, SEN S, et al. Field measurements of soot volume fractions in laminar partially premixed coflow ethylene/ air flames ［J］. Combustion and Flame, 2004, 138(4): 362-372.
［16］ SMYTH K C, SHADDIX C R. The elusive history of m=1.570.56i for the refractive index of soot ［J］. Combustion and Flame, 1996, 107(3): 314-320.
［17］ ZHU J, IRRERA A, CHOI M Y, et al. Measurement of light extinction constant of JP8 soot in the visible and nearinfrared spectrum ［J］. International Journal of Heat and Mass Transfer, 2004, 47(17/18): 3643-3648.
［18］ DE IULIIS S, BARBINI M, BENECCHI S, et al. 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.
［19］ KOEYLUE U, XING Y, ROSNER D E. Fractal morphology analysis of combustiongenerated aggregates using angular light scattering and electron microscope images ［J］. Langmuir, 1995, 11(12): 4848-4854.
［20］ SNELLING D R, THOMSON K A, SMALLWOOD G J, et al. Twodimensional imaging of soot volume fraction in laminar diffusion flames［J］. Applied Optics, 1999, 38(12): 2478-2485.
［21］ THOMSON K A, JOHNSON M R, SNELLING D R, et al. Diffuselight twodimensional lineofsight attenuation for soot concentration measurements［J］. Applied Optics, 2008, 47(5): 694-703. |
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|
Cited |
|
|
|
|
| |
Shared |
|
|
|
|
| |
Discussed |
|
|
|
|
