UNLIKE PARTICLES SIZE COLLISION MODEL IN 3D UNSTEADY POLYDISPERSED SIMULATION OF CIRCULATING FLUIDIZED BED

摘要

This paper presents a multi-fluid modeling approach, developed in the EDF 3D code Saturne_Polyphasique@Tlse, with separate transport equations for the mean velocity and fluctuant kinetic energy for each particulate phase. The collisions between unlike particles lead to additional source terms accounting for the mean and fluctuant momentum transfer between classes and modification of the effective transport property (viscosity, diffusivity) modeling. Simulation results for a cold Circulating Fluidized Bed (CFB) pilot (square section of 0.96 m~2, total height 10.4 m) with three particle size classes are presented. The polydispersed modeling approach allows to improve the 3D unsteady prediction of gas-solid circulating fluidized bed hydrodynamic, especially in regards of the circulation of the largest particles.