This PI System plugin is an ideal retrofit for meeting the Cross State EPA emissions program requirements. It offers an adaptive optimal supervisory Oxygen controller(1) for fossil fired boilers and will typically increase thermal efficiency of the boiler by more than one percent with corresponding reduction in heat rate and emissions.
The system is optimized for pulverized coal combustion. The controller uses multiple O2 and CO sensors (optional NOx) located in the economizer section of the boiler. The system automatically finds the “knee” of CO versus O2 curve representing the current combustion characteristics (state curve). Parameters in the combustion characteristic curve are continually estimated using recursive identification technology that compensates for changes in coal quality. The system is insensitive to changes boiler loads above 50 percent and is compensated for soot-blowing, blowdown, and startup disturbances.
The graphic presentation includes the dynamic characteristic curve and the optimal “target box” for CO and O2. The system monitors the performance of the system using percentage of time the “state” is inside the control box. The system can be run in man-in-loop control or direct supervisory control.
The system is implemented in PI-AF and PI-Notifications. It can be easily configured for any size boiler with multiple CO (NOx) and O2 sensors. The system automatically computes performance losses for not staying in the target box.