CFD Modeling of CFBC Boilers

PSLab JBNU (2017)

Process Flow

2

CFBC Boiler

Fuel: crushed coal of 3 to 6 mm size

Bed materials: sand + ash + limestone to reduce SO2emission

Fuel and bed materials circulated by cyclone separation after combustion

Startup by oil burner in the furnace

Combustion Reaction

3

CFBC Boiler

Gasification:C + H2O ⇄ CO + H2C + CO2 ⇄ 2CO

Combustion:2C + O2 ⇄ 2CO

Workflow

4

Modeling

Geometry

Geometry design

Geometry export for meshing

Geometry supplementation

Mesh topology design

Mesh manipulation

Mesh quality check & export

Boundary conditions

setting

Case configuration

Solve

Data source reading

Mesh Solution Visualization

Filtering

Rendering

5

Modeling Geometry

6

Modeling Mesh

7

Simulation Air Flow

• Air flow simulation

Pressure

8

Simulation Air Flow

Velocity

9

Simulation Air Flow

Flow vectors

10

Simulation Air Flow

Streamlines

11

Simulation Gas-Solid Two Phase Flow

Pressure (t = 30s)

12

Simulation Gas-Solid Two Phase Flow

Dispersed phase volume fractions (t = 30s)

13

Simulation Gas-Solid Two Phase Flow

Velocity (t = 30s)

14

Simulation Gas-Solid Two Phase Flow

Flow vectors (t = 30s)

15

Simulation Gas-Solid Two Phase Flow

Streamlines (t = 30s)

16

Simulation Combustion Reaction

Pressure (t = 30s)

17

Simulation Combustion Reaction

Temperature (t = 30s)

18

Simulation Combustion Reaction

Reactants (t = 30s)

19

Simulation Combustion Reaction

Products (t = 30s)

20

Simulation Combustion Reaction

Gas velocity (t = 30s)

21

Simulation Combustion Reaction

Streamlines (t = 30s)

Erosion

22

Case Study

Erosion patterns inside furnace