Operation control apparatus and operation control method for steam turbine

摘要

A speed controller generates a speed control output signal based on an output target value and a detected speed of a steam turbine, an extraction pressure controller generates an extraction pressure control output signal based on an extraction flow rate target value and a detected extraction pressure of the steam turbine, and when operation signals of a governor valve and an extraction control valve are generated with reference to an extraction map for deriving opening degrees of the valves at an operation point determined depending on the signals, the extraction map is used with a scale of the extraction pressure control output signal in the extraction map being corrected to be multiplied by “extraction flow rate target value/extraction flow rate actual value” based on a regularly detected extraction flow rate actual value of the steam turbine.

主权项

1. An operation control apparatus for a steam turbine including at least a high-pressure turbine and a low-pressure turbine, the steam turbine further including a governor valve that controls a flow rate of steam to be supplied to the high-pressure turbine, and an extraction control valve that controls a flow rate of steam to be supplied from the high-pressure turbine to the low-pressure turbine, the operation control apparatus comprising:
a speed controller that generates a speed control output signal based on an output target value of the steam turbine and a detected speed of the steam turbine; an extraction pressure controller that generates an extraction pressure control output signal based on an extraction flow rate target value of the steam turbine and a detected extraction pressure of the steam turbine; and an extraction map for deriving opening degrees of the governor valve and the extraction control valve at an operation point, the opening degrees being determined depending on the speed control output signal and the extraction pressure control output signal, wherein a scale of the extraction pressure control output signal in the extraction map is modified by multiplying the scale by a value that is derived by dividing the extraction flow rate target value with an extraction flow rate actual value, and operation signals for operating the governor valve and the extraction control valve are generated with reference to the modified extraction map.