Application of Improved Oxygenated Treatment on Ultra-Supercritical Unit with Precise Low Oxygen Content Dosing Technology

It is of vital importance to implement oxygenated treatment for(ultra) supercritical units to effectively inhibit flow accelerated corrosion in feed-water and high pressure heater drain systems. The improved oxygenated treatment with low oxygen content, appropriate feed-water pH value reduction and precise oxygen dosing technology is developed to solve the oxide scale problems in both the superheaters and the reheaters. Compared with the traditional oxygenated treatment using low oxygen content, this technology can further improve the economic efficiency of condensate polishing system, effectively inhibit flow accelerated corrosion in high pressure heater drain system and reduce its iron contents without any extra oxygen content increase in the steam, which not only eliminates the adverse effect of oxygen dosing on oxide scale exfoliation but also has the advantages of other oxygenated technologies. Its application on 1 000-MW ultra-supercritical unit shows good effects such that the whole water-steam circuit system is fully protected effectively.