Numerical Simulation And Experimental Research In Internally Circulating Fluidized Bed

The flow behavior of particles in the inner circulation fluidized bed was simulated by Fluent 6.1. Simulation results were verified by experiment, it provides some theoretic foundation for the design of asymmetry air distribution fluidized bed.The flow behavior of particles in the fluidized bed with V-shaped and∧-shaped air distributors were investigated respectively. Results showed that the gas velocity in the middle was lower than that at the two sides with the∧-shaped distributor. Particles in the middle move downward under the low velocity and the action of gravity, then move upward under the high velocity near the two sides. So the multiple fluidization, in which fluidized bed exists at two sides, and moving bed exists in the middle, will form under this flow condition. While gas velocity in the middle is higher than that at the two sides in the V-shaped distributor. The particles in the middle move upward under the high air velocity, then move downward under the low air velocity and gravity action at the two sides. So the multiple fluidization, in which fluidized bed exists in the middle and moving bed exists at the two sides, will form under this flow condition.The influence of ratio of high and low gas velocity on the flow behavior of particles in the bed was studied. The results show that the asymmetry air distribution is in favor of fluidization and formed the inner circulation of particles. But if the ratio is too small, the circulation couldn't form completely. On the contrary, the particles would pile up in the low-speed zone, which may lead to de- fluidization. So a conclusion could be drew that an optimum value that can form the best fluidization exists.The transient flow profiles were gained by means of photograph in the cold experiment. And the simulation results were compared with experiments. It showed that the simulation results agreed well with the experiments. So it could be seen that the fluent6.1 and Euler-Euler Two-Fluid model can simulate the real flow behavior in the asymmetry air distribution fluidized bed.