Abstract:Since the commissioning of the 1050MW ultra supercritical once through boiler for Unit 1 in Java, the feedwater has been treated with weak oxidation full volatilization, resulting in a rapid increase in boiler differential pressure, high iron precipitation in the feedwater and drainage, high scaling rate in the water-cooled wall tubes, and insufficient condensation water in the fine treatment mixed bed treatment during each regeneration cycle. Through the application research of the technology of converting the boiler feedwater from weak oxidation full volatilization treatment to oxygenation treatment, the variation of iron corrosion product precipitation in the feedwater under different oxygen addition and pH values was studied. By controlling the oxygen amount at the inlet of the economizer to 20-60 μ g/L and the feedwater pH to 8.7-9, the corrosion of the feedwater system and drainage system was significantly inhibited, and the iron precipitation of the feedwater corrosion product was reduced by 65.2%. The amount of iron precipitation in the hydrophobic corrosion product of the high-pressure reactor decreased by 84.4%, while the amount of iron precipitation in the hydrophobic reactor decreased by 82.0%; The continuous operation time of a single precision treatment mixed bed has been extended from less than a week to about 30 days, and the amount of condensate treated per cycle has been extended from 80000 to 130000 tons to over 300000 tons. The direct economic benefits have reached 2.005 million yuan/year, and the annual reduction of wastewater discharge has been 37600 tons, achieving good technical, economic, and social benefits.