Directing against the problem concening large fluctuation of feed-water flow resulted from the process of automatically putting two steam-driven feed-water pumps into parallel operation or stopping one from service during the time of load variation for supercritical 660 MW unit in Datong Power Generation Co Ltd

a control logic for solution of said problem has been designed on the basis of characters of unit no.10

and a control test for said pump's operation being carried out.According to this control logic

the fluctuation of feed-water flow into the boiler is less than 20 t/h during the time of putting two said pumps into parallel operation

and the fluctuation of feed-water flow into the boiler is less than 55 t/h in the event of one pump being stooped.It shows that the said control logic can satisfy the control requirement of the feed-water system

ensuring safety and stability in operation of unit.