The Long Period Of Time Application And Research Of 660 MW Ultra-super Critical Boiler Feedwater Oxygenated Treatment

The so-called plus oxygen treatment(Oxygenated Treatment), is a kind of O2 or H2O2 was added to make the metal surface thermodynamic system generates a dense uniform Fe3O4 and Fe2O3 double protection film, and a method by adding ammonia water to adjust the PH in boiler feed water value, making it alkaline to water treatment methods.Anhui Huadian Wuhu Power Company Limited on the 1st and the 2nd unit of 660 MW ultra-supercritical water- hydrogen unit, ammonia is added to the original use only all volatile treatment AVT(O) working conditions, the deposition rate of the boiler heating surface is faster, Wall economizer and a large amount of dirt, the higher iron content of water vapor system. This test is mainly to # 1, # 2 units to be converted to water conditions and oxygen conditions(OT), water vapor before the test was to check the quality of the unit set [1], by analyzing the influence of the oxide film protection performance factor, initially set to water and oxygen conditions, by testing to determine the feasibility of 660 MW ultra-supercritical units add oxygen treatment. Plus oxygen system after commissioning, first carried out and oxygen conversion test, the low-pressure and high-pressure water system to convert water systems to increase oxygen conditions. During the conversion of iron content measurement system, and according to changes in iron content, to test and adjust the PH value, considering the amount of ammonia added, corrosion of the system and the impact of fine treatment of water cycle, determine the control value PH value. After the test, after considering the system and economy, optimum conditions to be determined, for Water Treatment and programs were optimized and the effect of water and oxygen were evaluated.After adopted the oxygenated treatment, the iron content at all sampling points of the water vapor system of # 1and # 2 units are dropped sharply, and the flow accelerated corrosion is suppressed, so the scaling rate of the boiler heating surface is greatly reduced and the boiler chemical cleaning cycle is prolonged. Orifice plug phenomenon basically eliminates.The operation cycle of mixed bed of condensate polishing is prolonged and the water quality is improved obviously along with ammonification running state is less than before. Feedwater oxygenated treatment is feasible at 660 MW ultra-super critical units.