Visit Emerson at Electric Power
Booth #1259
May 6-8, 2008
Baltimore Convention Center
Baltimore, Maryland

SCR Temperature Optimization

Gary Sunderland, Constellation Energy
Harry Winn, Emerson Process Management Power & Water Solutions, Inc.

Optimizing the effectiveness of a Selective Catalytic Removal (SCR) systems is strategic in helping coal fired plants meet both NOx reduction targets and generation needs. The SCR installed at a 2 X 680 MW coal-fired plant mandates a minimum inlet flue gas temperature of 555° F to keep the SCR in service. An economizer bypass system allows flue gas to bypass the economizer section of the boiler and ‘re-mix’ with the economizer outlet flue gas to increase overall flue gas temperature to the desired level. During ozone season, however, the plant encountered difficulties in maintaining the minimum SCR inlet temperature due to heat loss and the limitations of existing control strategies.

This paper will describe the development and implementation of an SCR optimization strategy that allowed the plant to meet year-round NOx reduction targets at various load levels while also maintaining cost efficient operation.