With high power generation efficiency and low carbon emission

(ultra) supercritical unit is the main type in China's development of thermal power units. Optimization on feed water operating condition of the(ultra) supercritical unit is of great guiding significance. The optimal control indexes of different feed water operating conditions of(ultra) supercritical units are investigated by in-situ sampling test

and the influence of centralized sampling on feed water quality is researched. Moreover

the intelligent control system for feed water operating condition is developed. The results show that

the optimal target value of feed water conductivity is 6.7 μS/cm under AVT(O) condition

the optimal target value of feed water dissolved oxygen is 15 μg/L and the optimal target value of feed water conductivity is 3.0 μS/cm under OT condition. Long sampling pipeline of feed water will cause the deposition of iron corrosion products

and interfere with the judgment of unit corrosion. The chromates produced by adding oxygen to feed water is only related to the oxidation of the sampling tube and has nothing to do with the water vapor system.