SCR Retrofits Provide Opportunity for Variable Speed Fans

摘要

Large induced draft (ID) fans are perfect candidates for using medium voltage AC drive technology. The payback for these systems, from energy savings alone, is as little as three years for a base-loaded unit and sooner for units with wide load variation. When a power plant retrofits a selective catalytic reduction (SCR) system, the ID fans must be redesigned to handle the additional pressure drop of the SCR system. This can be achieved by modifying the existing fans or installing new fans. Because many SCR applications require up to 12,000 HP drive motors, an efficient system to drive and control the fan is a necessity.