REVOLUTION SPEED CONTROL DEVICE FOR FEED WATER PUMP

摘要

PURPOSE: To prevent breakage of a feed water pipe by providing a proportional unit to output a regulating valve opening command of a turbine, a setting unit to set the regulating valve opening command and a switch unit to switch an output of the proportional unit to an output of the setting unit. ;CONSTITUTION: A deviation between a revolution number command 1 of a feed water pump turbine and the actual revolution number 2 of the feed water pump turbine is inputted to a proportional unit 4. After a constant gain is multiplied, an output of the proportional unit 4 is inputted to a switch unit 10. In a normal operation, the switch unit is set on the (b) side, so that the output of the proportional unit 4 becomes a regulating valve opening command. A revolution number increasing rate is detected by a revolution number changing rate computing unit 7 and a revolution number high changing rate signal monitoring switch 8, and the switch unit 10 is set on the (a) side, so that an output signal of a setting unit 9 becomes a regulating valve opening signal 3. Even in an increase of a feed water pump delivery pressure due to a rapid increase in the number of revolutions of a feed water pump, the feed water pump delivery pressure never exceeds the highest working pressure of a feed water pipe. Thereby, breakage of the feed water pipe caused by an increase in the feed water pump delivery pressure can be prevented.;COPYRIGHT: (C)1993,JPO&Japio