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Title: Dynamic behavior and control requirements of an atmospheric fluidized-bed coal combustion power plant: A conceptual study

Abstract

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 thatmore » 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.« less

Authors:
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
OSTI Identifier:
6434393
Report Number(s):
ORNL/TM-9821
ON: DE87011970
DOE Contract Number:  
AC05-84OR21400
Resource Type:
Technical Report
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
Subject:
01 COAL, LIGNITE, AND PEAT; 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

Citation Formats

Smith, O. L. Dynamic behavior and control requirements of an atmospheric fluidized-bed coal combustion power plant: A conceptual study. United States: N. p., 1987. Web. doi:10.2172/6434393.
Smith, O. L. Dynamic behavior and control requirements of an atmospheric fluidized-bed coal combustion power plant: A conceptual study. United States. https://doi.org/10.2172/6434393
Smith, O. L. 1987. "Dynamic behavior and control requirements of an atmospheric fluidized-bed coal combustion power plant: A conceptual study". United States. https://doi.org/10.2172/6434393. https://www.osti.gov/servlets/purl/6434393.
@article{osti_6434393,
title = {Dynamic behavior and control requirements of an atmospheric fluidized-bed coal combustion power plant: A conceptual study},
author = {Smith, O. L.},
abstractNote = {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.},
doi = {10.2172/6434393},
url = {https://www.osti.gov/biblio/6434393}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Jun 01 00:00:00 EDT 1987},
month = {Mon Jun 01 00:00:00 EDT 1987}
}