Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
Study of bed fluidization through CFD analysis and simulation
Submission Author:
Fernando Léo Bueno de Oliveira e Silva , MG
Co-Authors:
Fernando Léo Bueno de Oliveira e Silva, Diego Carneiro de Oliveira, Letícia Colletta, Electo Eduardo Lora, Rubenildo Andrade
Presenter: Fernando Léo Bueno de Oliveira e Silva
doi://10.26678/ABCM.COBEM2021.COB2021-2056
Abstract
The computational fluid dynamics (CFD) is a tool useful to solve complex problems involving topics like thermodynamics, fluid mechanics, heat transfer, etc. It can reduce the cost and the need to construct and test physically a desired equipment through a simulation of the processes in many operational conditions, demonstrating the main characteristics to be focused in the experimental steps of a given project. Gasification is an emerging technology able to process solid combustible materials, like biomass (forestry and agricultural residues), anthropogenic residues (sewage sludge and municipal solid waste) and others. The products from gasification process are electricity, heat, chemicals, biofuels etc. Although, the gasification process has several challenges to be overcome, in the case of fluidized bed gasifiers one of the main difficulties is understand the bed behavior during fluidization. The fluidization is a complex phenomenon, hard to observe and measure in experimental apparatus, especially turbulent aspects. For this reason, the main objective of this work is to present the hydrodynamic behavior of a 2-D gas–solid fluidized bed using computational fluid dynamics software. The simulation output data were validated by comparing it with the experimental data obtained from the literature. The simulations were carried out by using bed material having 300 µm of particle diameter and a density of 2400 kg/m³ at different inlet gas velocities. Multiphase Eulerian-Eulerian model approach along with the kinetic theory of granular flow is used for simulating the gas–solid fluidization behavior. The minimum fluidization velocity conditions were calculated and inserted as an initial parameter for the CFD simulation. The momentum exchange coefficients were calculated using Syamlal-O’Brien functions. In the present work, the effects of inlet gas velocity, pressure drop and bed expansion ratio are discussed. The results obtained will be used to develop an experimental fluidized bed cold reactor and will be presented in a future paper.
Keywords
Gasification, fluidized bed, Fluidization, CFD
