CFD modeling of a commercial‐size circle‐draft biomass gasifier

Abstract

This work was focused on a commercial-size (2MWth.) circle-draft biomass gasifier. In this work a threedimensional transient CFD (computational fluid dynamics) model was established to simulate the circledraft biomass gasifier. The MP-PIC (multiphase particlein- cell) method was applied to simulate multiphase reactive flows in the gasifier. In the MP-PIC method, the Navier-Stokes equation coupled with the large-eddy simulation (LES) was applied to describe the gas phase. The particulate phase was described in a Lagrangian way by computing the trajectories of parcels of particles solving Newtonian equations of motion for each parcel. The mass and energy transport equations were coupled with the momentum equation to simulate mass and energy transfer in the circle-draft gasifier. The heterogeneous solid-gas and homogeneous gas-phase reaction kinetics were integrated with the transport equations to simulate biomass drying, gasification, combustion, and other gasphase reactions. The simulation results were compared with experimental data to validate the CFD model. The CFD model predicted gas species distribution, reaction zone temperatures, and producer gas composition in the circle-draft biomass gasifier