Integrated Real-time Optimization of Boiler and Post-combustion System in Coal-based Power Plants via Extremum Seeking
E. Schuster, C. Romero, Z. Yao and F. Si
IEEE Multi-conference on Systems and Control
Yokohama, Japan, September 8-10, 2010
Abstract
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AES Cayuga Unit 1 is a 160M W unit, equipped with a low nitrogen
oxide (NOx) firing system and an anhydrous ammonia (NH3),
TiO2/V2O5/WO3 selective catalytic reduction (SCR) system for
NOx emission control. An ammonium bisulfate (ABS) probe was retrofit
to the SCR to monitor ABS formation in real-time with the ultimate
goal of minimizing air preheater (APH) plugging (ABS concentration)
by regulating the APH bypass damper. Recent work on static
optimization of coal-based power plants has played a crucial role in
improving overall efficiency. However, static optimization falls
short in dealing with real-time scenario changes (i.e., cycling unit
load, coal quality, firing system maintenance conditions, subsystem
failures, plant aging, etc.). Extremum seeking (ES) is proposed in
this work to optimally tune boiler operation in order to minimize NOx
production in real-time. The effectiveness of the ES adaptive
controller in keeping the system at an optimal operation point in
presence of input disturbances and system changes is demonstrated
through simulations based on identified models of the boiler, SCR and
APH systems.