Interactive System for Pulverized Coal Combustion Visualization with

Fluid Simulator

Interactive System for Pulverized Coal Combustion Visualization with

Fluid Simulator

Marek Gayer, Pavel Slavík and František Hrdlička

Department of Computer Science and EngineeringFaculty of Electrical Engineering of CTU in Prague

Czech Republic

Visualization, Imaging and Image Processing (VIIP)

Malaga – Spain - September 9-12, 2002

w w w . c g g . c v u t . c z

Computer Graphics Group

2VIIP '2002

Outline of the presentationOutline of the presentation

Introduction and motivation Fluid flow modeling - CFD Our Fluid simulator Virtual coal particle system Simplified combustion and heat transfer Implementation and visualization Our results and their reliability Conclusion and future work

3VIIP '2002

Introduction and motivation to coal combustion visualizationIntroduction and motivation to coal combustion visualization

Both for the ecological and economical reasons)

Finding optimal boiler configurations.– To reduce pollution– To find a way for

optimal fuel preparation How can visualization help

4VIIP '2002

The modeling of fluid flow - CFDThe modeling of fluid flow - CFD

Most often: solving complex differential equations (e.g. Navier-Stokes)

Fluid simulators for computer graphics Coal combustion as an CFD application Current solutions and systems:

Precise, robust, well-known

Slow, no real-time

+

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5VIIP '2002

Our fluid simulatorOur fluid simulator Dividing the boiler area to

“voxel” arrays Mass fluxes and velocity

changes per time dt based on Newton’s second law and continuity equation

Principle of local simulation Is fast, easy to implement,

reusable but “unstable”

For more information, see our paper

6VIIP '2002

Virtual coal particle systemVirtual coal particle system Used both for simulation

and visualization of the combustion process

Virtual particle system approach

Movement determination:– Aerodynamic resistance– Gravity force

7VIIP '2002

Simplified combustion and heat transferSimplified combustion and heat transfer

The temperature array Statistical view of combustion process Basic coal properties Some of the combustion issues:

– Various combustion phase steps – Heat distribution to the particles and air– Heat radiation and to voxels and walls

8VIIP '2002

t = 0 seconds:

T = 303oC (above ignition)O2 concentration = 60%

Coal particle

Partially burned particle

C

C

C

t = 0.01 seconds:

T = 305oC (increased)O2 concentration = 57%

Partially burned coal particles

Coal particle transformed to burned ash particle

C

B

C

C

C

Interaction of virtual coal particlesInteraction of virtual coal particlesInteraction of virtual coal particlesInteraction of virtual coal particles

9VIIP '2002

Our interactive combustion systemOur interactive combustion system

10VIIP '2002

Our interactive combustion systemOur interactive combustion system

11VIIP '2002

Sample visualization of our system using particle systems and linear interpolation

Sample visualization of our system using particle systems and linear interpolation

Visualization of coal particles flowing from jets.

Visualization of coal particles flowing from jets.

Detail of coal particles flowing from jets.

Detail of coal particles flowing from jets.

12VIIP '2002

Results comparison - visual appearanceResults comparison - visual appearance

Velocities magnitude Our system | FLUENT 5.5

Velocities magnitude Our system | FLUENT 5.5

Temperatures Our system | FLUENT 5.5

Temperatures Our system | FLUENT 5.5

13VIIP '2002

Results comparison – global parametersResults comparison – global parameters

Parameter Our system FLUENT 5.5

Average Temperature 890 oC 1002 oC

Outlet Temperature 814 oC 1068 oC

Max Temperature 2546 oC 2488 oC

Average stream velocity 14 m/s 11 m/s

Average outlet velocity 56 m/s 48 m/s

Wattage 187 W/m3 232 W/m3

Mass total 21.1 kg 21.3 kg

Solution converge time Below 1 min 7 hours

Real-time simulation / visualization

Enabled, 10 FPS

Not available

14VIIP '2002

Results comparison – numerical approachResults comparison – numerical approach

Built-in numerical comparison code Statistically compares the results

between our system and FLUENT From 60% to 80% voxels are less than

20% different from FLUENT values (temperature, flow directions, ... )

15VIIP '2002

Conclusion and future researchConclusion and future research

Interactive 2D coal combustion system with:– Fast & simple real-time fluid simulator (reusable)– Simplified combustion engine– Real-time visualization using OpenGL– Results reliability tested with FLUENT– Designated for education and “preview” design

Future research: – Precision improvements – further to reality– Further testing on real boiler tasks– The real-time 3D combustion system experiment

16VIIP '2002

Thank you for your attention.Thank you for your attention.

???Do you have any questions ?