Biomass combustion in a fluidized-bed system: An integrated model for dynamic plant simulations

A model that can be used for dynamic simulation of fluidized-bed biomass combustion plants is presented. The model combines spatially concentrated (well-mixed) approaches for the fluidized bed and the ash separation cyclone with a one-dimensional plug-flow representation of the freeboard section. Simulation results are compared with steady-state experimental data for wood combustion in a laboratory-scale facility. Computed flue gas compositions are in good agreement with measured values, whereas some deviation is observed in fluidized-bed temperature. The integrated model provides reasonable accuracy at a high computational speed. Hence, it is appropriate, after coupling with a thermodynamic cycle, for real-time monitoring and control of distribution nets and electric grids supplied by various regenerative power sources. Possible model extension by a population balance for the fuel particles is briefly outlined.