Chalmers University of Technology Mixing phenomena in fluidized beds – diagnostics and observations Filip Johnsson, David Pallarès, Erik Sette Department of Energy and Environment Chalmers University of Technology, 412 96, Göteborg The 68th IEA-FBC meeting Beijing, China, 12-13 May, 2014
46
Embed
Mixing phenomena in fluidized beds diagnostics and observations · · 2017-02-21Mixing phenomena in fluidized beds – diagnostics and observations Filip Johnsson, David Pallarès,
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Chalmers University of Technology
Mixing phenomena in fluidized beds
– diagnostics and observations
Filip Johnsson, David Pallarès, Erik Sette
Department of Energy and Environment
Chalmers University of Technology, 412 96, Göteborg
The 68th IEA-FBC meeting
Beijing, China, 12-13 May, 2014
Chalmers University of Technology
Bubbling fluidized bed boiler (BFBC)
Circulating fluidized bed boiler (CFBC)
Chalmers University of Technology
Dual bed systems – indirect gasifier
2-4 MW integrated in Chalmers 12 MW CFB
Gasifier
fuel
Combustor
fuel
Chalmers University of Technology
Biomass gasification
Research and development at
Chalmers with associated
industries
Chalmers lab-reactor
Chalmers 2-4 MW
pilot plant
GoBiGas Phase 1
20 MW SNG demonstration plant
Göteborg Energi
GoBiGas Phase 2
80 MW SNG
Commercial plant
Göteborg Energi
2008 2012 2016
Chalmers University of Technology
Oxyfuel in fluidized-bed combustion
CFB Technology Metso Power (Now Valmet)
4 MW CFB Oxyfuel
Chalmers University of Technology
CFB & BFB characteristics • Group B solids
– CFB: Primary gas velocity > ut for major part of bed solids
– BFB: Primary gas velocity < ut for major part of bed solids
– Furnace wall-layer backmixing (dispersed core region flow)
• Low solids recirculation flux
– CFB: Gs < 10 kg/m2 s (oxyfuel: higher Gs may be required)
– BFB: No external solids flux
Chalmers University of Technology
Back-mixing:
Bottom-region
clustering/bubble flow
Back-mixing:
Splash-zone solids
cluster flow
Furnace wall-layer backmixing
(dispersed core region flow)
Bottom region/bed Splash zone Transport zone
Chalmers University of Technology
CFB characteristics result in:
• Good vertical solids mixing
• Limited lateral solids mixing
– Fuel mixing is crucial
– Important to establish basis for modeling of fuel mixing from known parameters (gas velocity, gas and solid properties, bed and gas distributor geometry)