Numerical simulation of the devolatilization of a moving coal particle

Journal Article · Fri May 15 00:00:00 EDT 2009 · Combustion and Flame

DOI:https://doi.org/10.1016/J.COMBUSTFLAME.2008.10.004· OSTI ID:21168996

Higuera, F J ^[1]

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1. E.T.S. Ingenieros Aeronauticos, UPM, Pza. Cardenal Cisneros 3, 28040 Madrid (Spain)

The devolatilization of an isolated coal particle moving relative to the surrounding gas is numerically simulated using a competing reaction model of the pyrolysis and assuming that the released volatiles burn in an infinitely thin diffusion flame around the particle or not at all. The temperature of the particle is assumed to be uniform and the effects of the heat of pyrolysis, the intraparticle mass transfer resistance, and the variation of the particle radius are neglected. The effects of the size and velocity of the particle and of the temperature and oxygen mass fraction of the gas on the particle and flame temperature histories, the devolatilization time and the yield of light and heavy volatiles are investigated. The motion of the particle may have an important effect on the shape and position of the flame of volatiles, but it has only a mild effect on the devolatilization process for the particle sizes typical of pulverized coal combustion. This effect increases for large particles or in the absence of radiation. The relative motion enhances the heat transfer between the particle and the gas, causing the devolatilization time to decrease at high gas temperatures and to increase at low gas temperatures. The numerical results are compared with a blowing-corrected Nusselt number correlation often used in heat transfer models of the process. (author)

• OSTI ID: 21168996
• Journal Information: Combustion and Flame, Vol. 156, Issue 5; Other Information: Elsevier Ltd. All rights reserved; ISSN 0010-2180
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
COAL
PARTICLES
DEVOLATILIZATION
PYROLYSIS
HEAT TRANSFER
SIMULATION
COMBUSTION
OXYGEN
VOLATILITY
NUSSELT NUMBER
TEMPERATURE DEPENDENCE
PARTICLE SIZE
COMBUSTION PROPERTIES
CORRELATIONS
MATHEMATICAL MODELS
SHAPE
VARIATIONS
VELOCITY
YIELDS
PULVERIZED FUELS
Numerical simulation