Numerical study of aeration flow angle on powder flow and thermal behaviors in fluidized bed particle solar receivers

Abstract

The particle flow and thermal characteristics in fluidized bed particle solar receivers with different aeration flow angles were numerically investigated by employing the Eulerian-Eulerian two-fluid model. The filtered drag correlation was utilized to characterize the interaction between SiC particles of Geldart-A classification and gas. The model underwent validation using experimental data from the literature, confirming that the simulated solid holdup and local heat transfer rate agreed well with the experimental measurements. Simulation results show that the particle volume fraction was higher along the walls in the bottom section. In both +45° and + 60°, the particles returned to the aeration flow region. The aeration had a relatively small impact on the particle distribution at the center, whereas the other two regions (x / D = 0.5 and 0.95) exhibited a significant decrease in particle volume fraction at the height of aeration injection. For different aeration injection structures, the equilibrium temperature rise reached approximately 51% of the difference between the wall and inlet temperatures. The temperature rise of particles in FBPSR was attributed to the direct heat transfer from the heating wall to particles and he return of hot particles.