GAS TURBINE CONTROL APPARATUS AND GAS TURBINE OUTPUT COMPUTING METHOD FOR A SINGLE-SHAFT TYPE COMBINED CYCLE POWER PLANT

摘要

A gas turbine control apparatus for a single-shaft typecombined cycle power plant is provided by which gas turbine outputis accurately computed during a circulating water reversing wash.operation. Vacuum down amount is computed from a generator outputsignal (31) immediately before the mentioned reversing washoperation and is corrected by being multiplied by a valve openingcorrection factor computed from a condenser reversing valve openingsignal (41) and a sea water temperature correction factor computedfrom a condenser reversing valve inlet sea water temperature signal(47). A condenser vacuum at the time of the reversing washoperation is computed by the corrected vacuum down amount beingsubtracted therefrom. A vacuum correction factor is computed basedon the computed condenser vacuum. A reference steam turbineoutput is computed based on a post-intercept valve steam pressuresignal (34) and a steam turbine output signal (54) is computed bymultiplying the reference steam turbine output by the vacuumcorrection factor. A gas turbine output signal (55) is computed bysubtracting the steam turbine output signal (54) from the generatoroutput signal (31).