The causes leading to high pressure difference and its rapid rise in once-through boilers of 2×600 MW supercritical units in Guohua Taicang Power Generation Co Ltd have been analysed.It is believed that the total volatilization treatment technology originally adopted for the feed-water isn't suitable for said units.For this

through test and adjustment

it is finally determined to use the oxygen-adding treatment technology for the feed-water.After said treatment

the iron content in the water-steam system has been decreased by a big margin

the iron content in feed-water at inlet of the economizer has reduced to below 1.0 μg/L

and the iron content in drain from the high-pressrue heater is also less than 1.0 μg/L

at the same time

the pressure difference in boilers is stabilized at a relatively lower level.Practice shows that the oxygen-adding treatment technology is suitable for being adopted to once-through boilers of supercritical units.