A Model of the Enhancement of Combustion of Coal-Water Slurry Fuels Using High-Intensity Acoustic Fields

Abstract

Combustion of coal-water slurry fuels is simulated in the presence of high-intensity acoustic fields which increases heat and mass transfer from the droplets and particles, and thereby enhances the combustion. The steady-slip velocity and acoustically induced slip velocity are calculated along particle trajectories, giving the augmented Nusselt and Sherwood numbers in the presence of high-intensity acoustic fields compared with no-sound conditions. The paper also presents the water evaporation and char burn-out history for particles with diameters between 90–110 μm exposed to sound pressure levels of 160–170 dB and compares the results to similar cases under no acoustic field. A decrease in the char burn-out length of about 12.1 percent at 160 dB, 18 percent at 165 dB, and 24 percent at 170 dB sound pressure level is obtained compared to the case with no sound for 100-μm particles introduced at centerline.