PURPOSE: To provide an improvement of response character, by giving a set value, in accordance with the main steam quantity due to a rapid change of the thermal power source, to a water-level control meter, when a water level of the drum is controlled through an operational processing of the water-level control meter and a signal from main team flow detector.
CONSTITUTION: A waste heat boiler of exhaust gas, that is a thermal power source, makes a repetition of two-state working of high and low heating operation. Though a steam, generated by the exhaust gas 4, is taken out from a main steam pipe 5, a change of the above described heating quantity is detected by a main steam quantity detector 11, with its change decided by a drive circuit 15 and outputted to a set value generator circuit 22. With a set value outputted to a water-level control meter 9 of the drum by the set value generator circuit 22, a feed-water control valve 14 is controlled on the basis of a difference from actual water level of the drum 1. In the drawing, the nuemral 8 shows the drum water-level detector, 13 the water-feed flow quantity detector, and 12 the water-feed flow control meter.
TAUCHI KUNIAKI
HAMANAKA KENGO
FUJITSUKA KOUJI
FUJII FUKUJIYU
