Dynamic behavior and control requirements of an atmospheric fluidized-bed coal combustion power plant: A conceptual study
A first-principles model of a nominal 20-MW atmospheric-pressure fluidized-bed coal combustion (AFBC) power plant was developed to provide insight into fundamental dynamic behavior of fluidized-bed systems. The control system included major loops for firing rate, steam pressure and temperature, forced and induced draft air flow, SO/sub 2/ emission, drum water level, evaporator recirculation, and bed level. The model was used to investigate system sensitivity to design features such as the distribution of heat transfer surface among the bed boiler and superheater and the out-of-bed superheater. Also calculated were the sensitivities of temperatures, pressures, and flow rates to changes in throttle, attemperator, and feedwater valve settings and forced and induced draft damper settings. The large bed mass, accounting for approx.40% of the active heat capacity, may vary under load change and could impact controller tuning. Model analysis indicated, however, that for the design studied, the change in bed mass does not appear to significantly affect controller tuning even if the bed mass varies appreciably under load-following conditions. Several bed designs are being considered for AFBC plants, some with partitions between bed sections and some without, and these differences may significantly affect the load-following capability of the plant. The results indicated that the slumping mode of operation can cause distortion of the heat source/sink distribution in the bed such that the load-following capability (rate of load change) of the plant may be reduced by as much as a factor of 5 compared with the mode in which tube surface is exposed. 9 refs., 13 figs., 6 tabs.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 6434393
- Report Number(s):
- ORNL/TM-9821; ON: DE87011970
- Resource Relation:
- Other Information: Portions of this document are illegible in microfiche products. Original copy available until stock is exhausted
- Country of Publication:
- United States
- Language:
- English
Similar Records
Integrated simulation of the Escatron PFBC power plant
Operating experience of the Tennessee Valley Authority`s 160-MW atmospheric fluidized bed combustion demonstration unit
Related Subjects
42 ENGINEERING
CONTROL SYSTEMS
DESIGN
MATHEMATICAL MODELS
SENSITIVITY
FLUIDIZED-BED COMBUSTORS
COAL
CONTROL
FLUIDIZED-BED COMBUSTION
CARBONACEOUS MATERIALS
CHEMICAL REACTIONS
COMBUSTION
COMBUSTORS
ENERGY SOURCES
FOSSIL FUELS
FUELS
MATERIALS
OXIDATION
THERMOCHEMICAL PROCESSES
014000* - Coal
Lignite
& Peat- Combustion
421000 - Engineering- Combustion Systems