Method for monitoring copper-alloy tubes for maintaining corrosion resistance and cleanliness factor of their inner surfaces

摘要

A method of monitoring the inner surfaces of copper-alloy condenser tubes of a condenser through which seawater flows as a coolant by controlling a ferrous-ion injecting operation to inject ferrous ions into the coolant for forming a protective film on the inner surfaces of the condenser tubes, and a sponge-ball cleaning operation to clean the inner tube surfaces by passing sponge balls through the condenser tubes. During an initial period of exposure of the condenser tubes to the coolant after installation of the condenser tubes in the condenser, the ferrous ions are injected into the coolant to form the protective film on the inner surfaces of the condenser tubes until the polarization resistance of the condenser tubes has reached 10.sup.4 &OHgr;cm.sup.2. Subsequently, the ferrous-ion injecting operation and the sponge-ball cleaning operation are executed while the polarization resistance and heat transfer rate of the condenser tubes are monitored. The injecting and cleaning operations are performed to maintain within suitable ranges the polarization resistance and the heat transfer rate of the condenser tubes. These ranges may vary, depending upon whether the coolant is non- chlorinated seawater, chlorinated seawater, or sulfide-ion polluted seawater.