Numerical study of the effect of inter-particle forces of large biomass on mixing before combustion

Subject Areas : Multiphase Flow

mahsa  baghaeifar ¹ (Department of Mechanical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran)
morteza  khayat ² (Department of Mechanical Engineering, Science and Research Branch, Islamic Azad University, Tehran,)
Mohammad Hassan  Nobakhti ³ (Department of mechanical engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran)

Received: 2021-02-15 Accepted : 2021-05-17 Published : 2021-06-10

Keywords: fluidized bed, biomass, Mixing, Geldart group D particles,

Abstract :

Numerical simulation of biomass gasification in a fluidized bed has been performed using a hybrid approach, in which the governing equations of the gas phase are solved in Eulerian framework and solid particles are modeled based on Multi Phase Particle-In-Cell (MP-PIC) using mixed Eulerian-Langerian method with closed-loop stochastic approach and the effect of operating factors such as gas velocity inlet to fluidized bed, particle density ratio and and particle size in fluidized bed on mixing quality have been investigated. The results show that the mixing quality reaches 0.97 by increasing the inlet velocity to eight times faster than the minimum fluidization velocity and 0.85 for the four times faster than the minimum fluidization velocity. Also by increasing the density ratio of biomass particles to fixed bed particles from 0.2 to 0.65, the mixing quality increases from 0.86 to 0.96. Furthermore, by reducing the diameter of biomass particles and fixed bed particles from 11 mm to 8 mm and 0.9 mm to 0.6 mm, respectively, the mixing quality increases from 0.8 to 0.95.