Investigation of heat transfer and combustion in the advanced fluidized bed Combustor (FBC). Technical progress report No. 8, [July 1, 1995--September 30, 1995]

This technical report summarizes the research performed and progress achieved during the period of July 1, 1995 to September 30, 1995. The measurements of gas flow in the bench-scale advanced FBC test chamber (10 in. I.D.) was conducted to better understand and utilize the fluid dynamics of gas and particle flows in the advanced FBC. A 3-dimensional directional probe was used for the measurements of the gas velocity and pressure. A pressure transducer and computer-assisted data acquisition system were employed to measure pressure fluctuations in the freeboard of test chamber. The test results show that the secondary air flow rate at the lower section affects the gas flow pattern in the test chamber by closing the upper four air nozzles. Also a stronger vortex flow circulation was formed between the center and near the wall region in the vertical direction. The other test results show that a large size of swirl pool above the nozzles was formed between the center and near the wall region in the vertical direction. These results indicate that the vigorous turbulence, such as swirling, recirculating, and developing gas-particle flow with intensified mixing and slip motion can contribute to intensification of the heat/mass transfer and large firing intensity, and high combustion efficiency. The gas/particle flow measurements will be continued in the freeboard of test chamber with an improved computer-assisted data acquisition system. Mathematical modeling/simulation on gas/particle flow will be performed to compare with the experimental results and numerical data