Development of a new method for improving load turndown in fluidized bed combustors: Final report

Technical Report · Thu Dec 01 04:00:00 EST 1988

DOI:https://doi.org/10.2172/5930525· OSTI ID:5930525

Brown, R. C.

The objective of this research was to investigate a new concept in fluidized bed design that improves load turndown capability. This improvement is accomplished by independently controlling heat transfer and combustion in the combustor. The design consists of two fluidized beds, one central and one annular. The central bed serves as the combustion bed. The annular bed is fluidized separately from the combustion bed and its level of fluidization determine the overall heat transfer rate from the combustion bed to the surrounding water jacket. Early theoretical considerations suggested a load turndown exceeding ten was possible for this design. This research consisted of three major phases: development of a computational model to predict heat transfer in the two-bed combustor, heat transfer measurements in hot-and-cold flow models of the combustor, and combustion tests in an optimally designed combustor. The computation model was useful in selecting the design of the combustor. Annular bed width and particle sizes were chosen with the aid of the model. The heat transfer tests were performed to determine if the existing correlations for fluidized bed heat transfer coefficients were sufficiently accurate for high aspect ratio fluidized beds (such as the annular bed in the combustor). Combustion tests were performed in an optimally designed combustor. Three fuel forms were used: double screened, crushed coal, coal-water-limestone mixtures (CWLM), and coal-limestone briquettes. 18 refs., 30 figs., 8 tabs.

• Research Organization: Iowa State Univ. of Science and Technology, Ames, IA (USA)
• DOE Contract Number: AC21-86MC23248
• OSTI ID: 5930525
• Report Number(s): DOE/MC/23248-2709; ON: DE89000994
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
014000* -- Coal
Lignite
& Peat-- Combustion
42 ENGINEERING
421000 -- Engineering-- Combustion Systems
CARBONACEOUS MATERIALS
CHALCOGENIDES
COAL
COMBUSTORS
CORRELATIONS
DESIGN
DISPERSIONS
DOCUMENT TYPES
ENERGY SOURCES
ENERGY TRANSFER
FLUIDIZED-BED COMBUSTORS
FOSSIL FUELS
FUEL SLURRIES
FUELS
HEAT TRANSFER
MATERIALS
MATHEMATICAL MODELS
MIXTURES
NITROGEN COMPOUNDS
NITROGEN OXIDES
OXIDES
OXYGEN COMPOUNDS
PROGRESS REPORT
SLURRIES
SUSPENSIONS