Reason Analysis and Control Strategy on Operation Corrosion in Direct Air-cooled Condensers (ACC)

Abstract

The operation corrosion in direct air-cooled condensers (ACC) had been widespread in china. Various water treatment devices were used for condensate water in order to control feedwater iron concentration below the limit according to guidelines, however direct ACC operation corrosion still existed and needed a thorough solution. Ammonia has a lower partition coefficient in the initial condensate, as well acidic anions are concentrated in the initial condensate, thus the initial condensate has lower pH, which results in the above mentioned corrosion. To reduce the direct ACC operation corrosion, methods could be applied, such as dosing higher ammonia in feedwater or dosing some organic alkalizing reagent in exhaust steam as an auxiliary. Keywords—thermal power plant; direct air cooling unit; air condenser; operating corrosion; corrosion control; alkalizing agent