This paper studies the effect of Yongqing re -regulating reservoir on the waterquality of lower reaches of Jilin section by analyzing the changes of carrying capacity and water quality atdifferent discharges,and proposes the minimum discharge of Yongqing re-regulating reservoir by takingaccount.

This article comprehensively analyses some malfunction,happened during commission and operation,on the feedwater system of the 700 MW unit of Zhuhai Power Station,and introduce some effective measures,such as the pump warming,the minimum flow control valve adjustment,extreme operation condition and the reliability of the feedwater system.

A method of controlling the recirculatary valve for minimum flow rate of feed-water by using the hysteresis function method has been put forward for preventing occurrence of cavitation in feed-water pumps.