CFD modeling of biomass combustion and gasification in fluidized bed reactors using a distribution kernel method

Numerical Study and Experimental Verification of Biomass Conversion and Potassium Release in a 140 kW Entrained Flow Gasifier

“…The solid particles are tracked in a Lagrangian frame, and the coarse grain method (CGM) is used to reduce the computational time. In CGM, the particles with similar properties at the same location are grouped together in parcels, and the governing equations are solved for parcels instead of particles . The momentum equation for each parcel is based on Newton’s second law of motion where gravity and drag are the forces acting on the parcel normald m italici v italici normald t = f normalD , italici + g ( 1 − ρ ρ i ) m italici where m i , ρ i , and v i are the mass, density, and velocity of the i th parcel, and f D, i is the drag force acting on the parcel, which is calculated based on the parcel’s velocity relative to the gas-phase velocity ( U – v i ) .…”

“…In CGM, the particles with similar properties at the same location are grouped together in parcels, and the governing equations are solved for parcels instead of particles. 40 The momentum equation for each parcel is based on Newton’s second law of motion where gravity and drag are the forces acting on the parcel where m i , ρ i , and v i are the mass, density, and velocity of the i th parcel, and f D, i is the drag force acting on the parcel, which is calculated based on the parcel’s velocity relative to the gas-phase velocity ( U – v i ). 36 The mass and energy balances for the parcels are and where the convective heat transfer from surrounding gas to the particles can be calculated by In the above equations, c p i and T i are the specific heat capacity and temperature of the parcel, respectively.…”

“…In CGM, the particles with similar properties at the same location are grouped together in parcels, and the governing equations are solved for parcels instead of particles. 40 The momentum equation for each parcel is based on Newton's second law of motion where gravity and drag are the forces acting on the parcel i k j j j j j y…”

“…A set of global gas-phase reactions that are used in previous studies on biomass gasification ,,, is considered here. In addition, another global reaction is added to include C 2 H 6 combustion with oxygen .…”

“…Computational fluid dynamics (CFD) simulation is considered a strong tool to study the performance of biomass conversion systems. ,, The most common approach to model the multiphase flow in a gasifier is to use a Eulerian–Lagrangian approach, ,− in which the fluid is treated as a continuous phase, and particles are treated as dispersed phases . Since the number of particles in a real case is very high, a coarse-grain method is commonly used to reduce the computational cost of the model.…”