Achieving NO{sub}x Emissions of Less Than 0.10 lb/mmBtu in a 600 MWe Tangentially Fired Boiler Burning PRB Coal Using Combustion System Modifications

摘要

In June 2001 the Lower Colorado River Authority (LCRA) entered into a competitively bid contract with ALSTOM Power Inc. (ALSTOM) to design, supply and install low NO{sub}x equipment for Fayette Power Project Units 1 and 2. The low NO{sub}x system was installed on Unit 1 during a fall 2002 outage. ALSTOM tuned the modified firing system during the contracted time period, achieving emissions that were lower than the contractual guarantees. After the Low NO{sub}x Concentric Firing System (LNCFS) was commissioned, LCRA continued to tune the boiler and further reduced NO{sub}x emissions. The capabilities of both the modified firing system and the existing control system have been utilized to minimize emissions, even while plant load varied. NO{sub}x emissions that resulted in a yearly average of 0.12 lb/mmBtu and monthly averages of less than 0.10 lb/mmBtu have been achieved. Fly ash Unburned Carbon (UBC) remained essentially unchanged from pre-retrofit levels, and Carbon Monoxide (CO) emissions of less than 200 ppm were also achieved.