关键词: 超超临界机组, 锅炉, 给水, 加氧处理, 氧化膜

Abstract: In this paper the effect of oxygenated treatment(OT) for boiler feedwater of Unit 2(a 1 000-MW ultra supercritical unit) at Huaneng Haimen Power Plant is summaried and analyzed. Since OT is used for the unit, the iron concentration atthe economizer inlet and in the high-pressure heater has been reduced to less than 1 μg/L, and decreased by more than 80% of that of all volatile treatment (oxidation) (AVT(O)), which effectively inhibits flow-accelerated corrosion in the feedwater and high-pressure heater drainage systems, reduces the iron transport and lowers the scaling rate in the economizer and on the water walls. The long-term operating experience shows that OT can not only slow down the boiler pressure dropping rate and avoid blocking of the drainage water control valve for the high-pressure heater, but also increasethe periodic water output of mixed bed in the condensate polishing system from 80 000 tons to 400 000 ton S, indicating a very considerable result of energy saving and consumption reducing, which is significant in improving the safety, reliability and economy of the unit.

Key words: ultra supercritical unit, boiler, feedwater, oxygenated treatment (OT), oxide film