Power Generation and Gasification
Circulating Fluidized Bed (CFB) Combustors utilize a fluidized bed within the furnace to provide numerous advantages, including extremely low NOx emissions, flex fuel capabilities, plus the addition of limestone particulates can capture 98% of the sulfur. Barracuda has been used to successfully understand complex furnace behavior such as fuel-air residence times, solids recirculation and bed mixing problems, bed entrainment rates and local wear. A CFB unit's large cyclone can be grade-optimized; and the loop seal upset behavior can be mitigated.
Gasification of coal and/or biomass material produces 'syngas' CO and H2 for fuel or chemical plant feedstock. Barracuda is being used today to study gas-solids phenomena inside an experimental combustors and gasifiers at DOE's National Energy Technology Laboratory. It is also being applied to commercial deepbed gasifiers with a static bed height of over 30 meters of coke. TRI, Inc. uses Barracuda for a state-of-the-art biomass thermochemical conversion design employing sand as the heat transfer medium with MSW or bioparticles, thus a multi-particle formulation is required.
Barracuda's Chemical Reactions module quantifies the production yields along with an accurate tally of solids consumption; the reactions automatically results in particulate size reduction which effects fluidization and elutriation rates.
Plant Components→ Issues
- Furnace geometry → optimize fuel/air mixing
- Cyclones → efficiency and reliability
- Loop Seal → aeration / plugging / clearing
- Feedline / Valves / Withdrawal → location, wear, number
- Combustor Startup → full loop performance
- Economics → conversion, yields
- Fluid bed expansion / density
- Bed carryover (entrainment) rate & PSD
- Segregation / recirc of size/materials (ash)
- Incomplete Combustion
- Stability, startup, off-normal transient behavior