초록 ▼

An operation control apparatus and an operation control method for a single-shaft combined plant are provided. A clutch is engaged and disengaged, whereby a gas turbine (power generator) is connected to and disconnected from a steam turbine. The opening of IGV is controlled by an opening command, th

An operation control apparatus and an operation control method for a single-shaft combined plant are provided. A clutch is engaged and disengaged, whereby a gas turbine (power generator) is connected to and disconnected from a steam turbine. The opening of IGV is controlled by an opening command, the opening of a burner bypass valve is controlled by another opening command, and the openings of fuel flow control valves are controlled by other opening commands found based on a pilot ratio. The commands to the IGV and the burner bypass valve and the pilot ratio are found during an isolated operation in which only the gas turbine is operated, during a joint operation in which the gas turbine and the steam turbine are both operated, during a transition from the isolated operation to the joint operation, and during a transition from the joint operation to the isolated operation. Thus, the pilot ratio and the fuel-air ratio of the gas turbine are optimized according to the state of operation, so that whether the clutch is disengaged or engaged, the combustion state of the gas turbine is stabilized.

대표청구항 ▼

1. An operation control apparatus for application to a single-shaft combined plant, said single-shaft combined plant comprising a gas turbine, a power generator, and a steam turbine connected together by a single shaft, and a clutch provided on said shaft for connecting said gas turbine and said pow

1. An operation control apparatus for application to a single-shaft combined plant, said single-shaft combined plant comprising a gas turbine, a power generator, and a steam turbine connected together by a single shaft, and a clutch provided on said shaft for connecting said gas turbine and said power generator to said steam turbine and disconnecting said gas turbine and said power generator from said steam turbine, said steam turbine being supplied with steam from an exhaust gas boiler for generating steam by use of an exhaust gas from said gas turbine,said operation control apparatus being adapted to find an inlet guide vane opening command for controlling an opening of an inlet guide vane provided in a compressor of said gas turbine and control the opening of said inlet guide vane; to find a burner bypass valve opening command for controlling an opening of a burner bypass valve provided in a burner of said gas turbine and control the opening of said burner bypass valve; and to find a pilot ratio, a ratio between a main fuel and a pilot fuel fed to said burner, and control openings of a main fuel flow control valve and a pilot fuel flow control valve in accordance with said pilot ratio,said operation control apparatus comprising:a computing facility unit for converting a steam pressure of steam flowing into said steam turbine into a steam turbine output; subtracting said steam turbine output from a power generator output of said power generator to find a gas turbine output; and finding a fuel flow rate command of a value corresponding to a deviation of said power generator output from a target power generator output;a state signal generator for outputting an engaged state signal when said clutch is engaged; outputting a disengaged state signal when said clutch is disengaged; increasing a value of said engaged state signal gradually and also decreasing a value of said disengaged state signal gradually to zero in a predetermined transitional period starting at a time of engagement when said clutch in disengagement is engaged; and decreasing the value of said engaged state signal gradually to zero and also increasing the value of said disengaged state signal gradually in a predetermined transitional period starting at a time of disengagement when said clutch in engagement is disengaged;an inlet guide vane opening command computing facility unit which has a first inlet guide vane opening command computing function capable of finding an optimal inlet guide vane opening command from said gas turbine output in an engaged state of said clutch, and a second inlet guide vane opening command computing function capable of finding an optimal inlet guide vane opening command from said gas turbine output in a disengaged state of said clutch; and which combines said inlet guide vane opening commands, found by said first and second inlet guide vane opening command computing functions, at rates corresponding to the values of said engaged state signal and said disengaged state signal to compute a final inlet guide vane opening command;a burner bypass valve opening command computing facility unit which has a first burner bypass valve opening command computing function capable of finding an optimal burner bypass valve opening command from said gas turbine output in the engaged state of said clutch, and a second burner bypass valve opening command computing function capable of finding an optimal burner bypass valve opening command from said gas turbine output in the disengaged state of said clutch; and which combines said burner bypass valve opening commands, found by said first and second burner bypass valve opening command computing functions, at rates corresponding to the values of said engaged state signal and said disengaged state signal to compute a final burner bypass valve opening command; anda pilot ratio computing facility unit which has a first pilot ratio computing function capable of finding an optimal pilot ratio from said fuel flo w rate command in the engaged state of said clutch, and a second pilot ratio computing function capable of finding an optimal pilot ratio from said fuel flow rate command in the disengaged state of said clutch; and which combines said pilot ratios, found by said first and second pilot ratio computing functions, at rates corresponding to the values of said engaged state signal and said disengaged state signal to compute a final pilot ratio. 2. An operation control method for application to a single-shaft combined plant, said single-shaft combined plant comprising a gas turbine, a power generator, and a steam turbine connected together by a single shaft, and a clutch provided on said shaft for connecting said gas turbine and said power generator to said steam turbine and disconnecting said gas turbine and said power generator from said steam turbine, said steam turbine being supplied with steam from an exhaust gas boiler for generating steam by use of an exhaust gas from said gas turbine,said operation control method being adapted to find an inlet guide vane opening command for controlling an opening of an inlet guide vane provided in a compressor of said gas turbine and control the opening of said inlet guide vane; to find a burner bypass valve opening command for controlling an opening of a burner bypass valve provided in a burner of said gas turbine and control the opening of said burner bypass valve; and to find a pilot ratio, a ratio between a main fuel and a pilot fuel fed to said burner, and control openings of a main fuel flow control valve and a pilot fuel flow control valve in accordance with said pilot ratio,said operation control method comprising:converting a steam pressure of steam flowing into said steam turbine into a steam turbine output; subtracting said steam turbine output from a power generator output of said power generator to find a gas turbine output; and finding a fuel flow rate command of a value corresponding to a deviation of said power generator output from a target power generator output;outputting an engaged state signal when said clutch is engaged; outputting a disengaged state signal when said clutch is disengaged; increasing a value of said engaged state signal gradually and also decreasing a value of said disengaged state signal gradually to zero in a predetermined transitional period starting at a time of engagement when said clutch in disengagement is engaged; and decreasing the value of said engaged state signal gradually to zero and also increasing the value of said disengaged state signal gradually in a predetermined transitional period starting at a time of disengagement when said clutch in engagement is disengaged;using a first inlet guide vane opening command computing function capable of finding an optimal inlet guide vane opening command from said gas turbine output in an engaged state of said clutch, and a second inlet guide vane opening command computing function capable of finding an optimal inlet guide vane opening command from said gas turbine output in a disengaged state of said clutch; and combining said inlet guide vane opening commands, found by said first and second inlet guide vane opening command computing functions, at rates corresponding to the values of said engaged state signal and said disengaged state signal to produce a final inlet guide vane opening command;using a first burner bypass valve opening command computing function capable of finding an optimal burner bypass valve opening command from said gas turbine output in the engaged state of said clutch, and a second burner bypass valve opening command computing function capable of finding an optimal burner bypass valve opening command from said gas turbine output in the disengaged state of said clutch; and combining said burner bypass valve opening commands, found by said first and second burner bypass valve opening command computing functions, at rates corresponding to the values of said engaged state signal and said disengaged state signal to produce a final burner bypass valve opening command; andusing a first pilot ratio computing function capable of finding an optimal pilot ratio from said fuel flow rate command in the engaged state of said clutch, and a second pilot ratio computing function capable of finding an optimal pilot ratio from said fuel flow rate command in the disengaged state of said clutch; and combining said pilot ratios, found by said first and second pilot ratio computing functions, at rates corresponding to the values of said engaged state signal and said disengaged state signal to produce a final pilot ratio.