CHEMICAL CLEANING OF UTILITY ONCE-THROUGH GENERATING UNITS THAT HAVE BEEN ON LONG TERM OXYGENATED TREATMENT (OT)

摘要

Two case studies are presented that review the design, execution, and results of chemical cleaning onrnutility once-through generating units.rnOT was first introduced into the U.S. in 1991. The OT application was successfully demonstrated on arnnumber of utility once-through generating units. Many in the utility industry quickly made the transitionrnfrom all-volatile treatment (AVT) to OT based on these successful applications.rnPrior to OT, once-through generating units were chemical cleaned on a preventive maintenance basisrn(which ranged from 18-36 months). With the advent of OT in the United States, it was touted in thernutility industry that chemical cleaning would no longer be required on once-through generating units.rnOperator experience has shown that chemical cleaning of once-through generating units cannot bernavoided but that the frequency rate can be extended out to beyond 8 years.