Study On Application Of Filling Oxygen Into Feed Water Of Supercritical Boileis In Yuhuan Power Plant

Water Oxygenated Treatment (OT) is used to inactivate metal by covering a layer of iron oxide hydrate(FeOOH) on the surface of metal for the dissolved oxygen in water, which is a dense and stable protective oxide film to reduce the iron content of water and prevent the occurrence of flow accelerated corrosion (FAC) of blast furnace system. Thereby, the protective film can reduce the fouling rate of the boiler tubes, slow the rate of increase of boiler operating pressure and prolong the cycle of chemical cleaning, boiler condensate polishing and mixed bed operation.In supercritical units, the water supply system is AVT (O, which provides a good quality of steam, but leads to some problems such as the deposition of magnetite in the choke coil, temperature excursion in the water cooled wall. To solve these problems, we design the project of feed water directional OT, and carried out the feed water adding oxygen experiment and oxidation treatment test.It was proved that the iron content of water vapor system in unit #4 was significantly decreased after adding oxygen. The small doses of oxygen steadily can prevent the disappearance of the oxide film and suppress the iron dissolution of water vapor after fully transforming feed water system. The iron content is partly reduced in hydrophobicity to slow the water cooled wall cutting circle scaling problem.