| 摘要 |
PROBLEM TO BE SOLVED: To provide a feedwater pump excess flow prevention apparatus that can prevent an excess flow rate of feedwater discharged from a feedwater pump, especially in a low range of feedwater flow rates, even when valve characteristics of a flow control valve disposed in a feedwater system change through long use thereof. SOLUTION: The feedwater pump excess flow prevention apparatus comprises a change rate limitation means 24 for outputting a condition signal input from a condition output means 24c as limiting the rate of change thereof, an addition means 25 for adding the signal output from the change rate limitation means 24 to a valve limit position signal 20a, an input comparison and output means 26 for comparing the output of the addition means 25 with the valve limit position signal 20a and outputting the difference as a corrected valve limit position signal 27a, and a flow control valve low limiter 28 for inputting the corrected valve limit position signal 27a based on the output signal of the input comparison and output means 26 as a lower limit value. COPYRIGHT: (C)2008,JPO&INPIT
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