Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
PARTICLE FRAGMENTATION EFFECT ON THE SOLID FUEL COMBUSTION MODELING IN A DROP TUBE FURNACE
Submission Author:
Vítor Lumertz , RS
Co-Authors:
Vítor Lumertz, Fernando Pereira, Juliana Pohlmann, Amanda Tavares de Oliveira, Roberto Coelho Andriotti, Paulo Smith Schneider
Presenter: Vítor Lumertz
doi://10.26678/ABCM.COBEM2021.COB2021-0411
Abstract
Solid fuels are the main source for electric power production in the world. In 2020, electricity generation from coal represented 33% of the total. Although biomass is not representative in the world matrix, it represents approximately 9% in Brazil. Thus, the study on how each fuel burns is important to predict the behavior of the particles during combustion, as well as to optimize industrial power plants operation. Furthermore, the increasing use of Computational Fluid Dynamics (CFD) simulations renewed the interest in determining kinetic parameters of pulverised fuels. Drop Tube Furnaces (DTF) are frequently used in studies of solid fuels because they can provide similar combustion conditions of those found in industrial power plants, such as high heating rates and short residence times. The objective of this paper is to study how the particle fragmentation process affects the modeling of solid fuels combustion in a DTF. The model is a one-dimensional Lagrangian model that tracks the particle history within the furnace, including the particle heating, devolatilization and char combustion. The simulation considers the particle size distribution (PSD), dividing the sample in different classes, each one with an initial diameter. It makes the model’s results more fitted with the experimental data in comparison with those obtained with a unique mean diameter. An optimization procedure is employed to find kinetic parameters of the fuel by comparison with experimental results. Since smaller particles burn faster, the fragmentation process increases the conversion rate. If this process is ignored, the kinetic parameters obtained from an optimization process may not be representative of the fuel. In this paper, the results of the simulations are compared for both cases when the model includes the particle fragmentation process and when it does not. Among others results, the evolution of the PSD, the burnout curve and the new kinetic parameters can be evaluated.
Keywords
Particle fragmentation, Kinetic parameters, Numerical Modeling, Drop tube furnace, Pulverised fuel
