Flow Restrictions in Water-Cooled Generator Stator Colils:Prevention,Diagnosis and Removal Part 2:Detection of Flow Restrictions in Water-Cooled Generator Stator Colis

摘要

Useful methods for detecting flow restrictions in stator bar cooling channels are the review of operating parameters and history vs.original design,of generator cooling water chemistry,of strainer and filter clogging history and of results from diagnostic chemical cleaning,as well as monitoring of stator water flow vs.pressure drop,individual stator bar water flow measurements,monitoring of on-line stator temperatures,visual inspections,and DC Hipot testing.A comnbination of these methods can be selected under consideration of plant specific hardware features and the cost-to-benefit relation. A proactive approach to detecting flow restrictions is recommended in order to permit advanced planning of corrective action,thus reducing the risk of unplanned maintenance downitime,or even component failure.Managing flow restrictions at an early stage reduces the risk of severe plugging of conductors,which may be very difficult to remove later on.