Heat transfer from immersed tubes in a pulsating fluidized bed

Abstract

Heat transfer through immersed tubes in pulsating fluidized beds was investigated computationally using an Eulerian-Eulerian approach. The effects of pulsating frequency and configuration of the immersed tubes were studied. At low pulsating frequency, more orderly bubbling behaviors were observed and these gave rise to more uniform heat transfer rates from all tubes. An interesting heat transfer behavior whereby the heat transfer coefficient distribution around an immersed tube alternated between a needle-like and a wide fan-shaped pattern was observed for the first time in this study. An increase in pulsating frequency caused the fluidized bed to exhibit fluctuating heat transfer rates. The staggered tube configuration considered in this study was observed to aid in the development of more orderly bubbling behaviors, with heat transfer coefficient of tubes in the bottom row exhibiting similar oscillation amplitudes.