97/03060 Modeling combustion and fly ash production in a pulverized coal-fired furnace

• Publisher: Elsevier Science
• Year: 1997
• Weight: 205 KB
• Volume: 38
• Category: Article
• ISSN: 0140-6701
• DOI: 10.1016/s0140-6701(97)84937-5

✦ Synopsis

97103054

The interaction of liquid reacting droplets with the pulsating flow in a Rijke-tube combustor Carvalho, J. A. et al. Combustion and Flame, 1997, 108, (l/2), 87-103. A theoretical investigation on the characteristics of a reacting liquid droplet in the self-generated oscillatory flow of a Rijke-pulse combustor was conducted. The droplet motion equation, accounting for droplet evaporation due to combustion, was solved using a fourth-order, Runge-Kutta method. The model was applied to a Rijke-type, alcohol-fired combustor for which experimental data exist for use as entrance parameters. The authors came to the following conclusions on studying the results of the experiments.

Pulsating flames of liquid fuels are shorter than the corresponding steady flames for a range of droplet initial velocity, because of a reduction in lifetime of droplets with the same initial diameter in the pulsating flow. In addition, for a range of droplet initial diameter, timeresolved heat generation rates from pulsating sprays exhibit a preferred frequency equal to twice the frequency of the pulsating flow. Droplet initial diameter, droplet initial velocity, and location of the spray in the tube were found to influence the excitation and maintenance of acoustic oscillations in a Rijke-type combustor based on evaluation of the Rayleigh integral over time and volume in the combustor. Experimental observations are used to verify the theoretical results presented and discussed.