| 摘要 |
PROBLEM TO BE SOLVED: To secure a minimum flow rate of a water supply pump even if a drum water level is largely fluctuated, and to perform stable drum water level control.SOLUTION: A water supply control device applied to a steam turbine plant, which supplies water from a water supply pump 1 to a steam drum 7 of a boiler via a supply water flow rate control valve 5, is configured to control a flow rate of supply water to the steam drum 7 by operating the supply water flow rate control valve 5 by means of three-element control based on a water level, a steam flow rate and a supply water flow rate of the steam drum 7, or single element control based on the water level of the steam drum 7, so as to keep a water level of the steam drum 7 constant. The supply water control device includes a control switching means for switching from the three-element control to the single element control when the water level of the steam drum 7 rises and exceeds a predetermined value. |
