Gas turbine control device and gas turbine system
View Patent ↗An object of the present invention is to provide a gas turbine control device which is capable of performing correction on the basis of a fuel composition of fuel gas to be supplied to a gas turbine, and is capable of changing an amount of correction in response to variation with time of the gas turbine. To attain this, a frequency analyzing unit 25 performs a frequency analysis of combustion oscillation of a combustor and splits a result of the analysis into respective frequency bands. Then, a state grasping unit 22 checks an operating state of the gas turbine on the basis of the result of the analysis of the combustion oscillation and process value of the gas turbine, and corrects the checked operating state on the basis of a fuel composition or a heat capacity of fuel gas measured by a fuel characteristic measuring unit 200 . A countermeasure determining unit 23 conducts a countermeasure for controlling an operating action of the gas turbine on the basis of the operating state thus checked.
1. A gas turbine control device, comprising:
a frequency analyzing unit for performing a frequency analysis of combustion oscillation in a combustor of a gas turbine and for splitting a result of this frequency analysis into a plurality of respective frequency bands;
a fuel characteristic estimating unit having at least three thresholds that are preset for categorizing a fuel characteristic into at least four categories, said fuel characteristic estimating unit configured to compare said at least three thresholds with a ratio between an output of the gas turbine and a fuel flow rate of the fuel and to determine which one out of said at least four categories, the fuel characteristic of the fuel corresponds to;
an inputting unit to which a process value of the gas turbine other than a fuel composition and a heat capacity of the fuel is inputted;
a state grasping unit for checking a current state of operation of the gas turbine by using the result of the frequency analysis split into the respective frequency bands from the frequency analyzing unit, the process value of the gas turbine from the inputting unit, and the category of the fuel characteristic determined by the fuel characteristic estimating unit;
a countermeasure determining unit for determining an increase or decrease in a flow rate of at least one of the fuel flow rate and an air flow rate to the combustor on the basis of the current state of operation of the gas turbine checked by the state grasping unit; and
an outputting unit for outputting an operation amount corresponding to a countermeasure determined by the countermeasure determining unit, in which a history indicating a relation between the category of the fuel characteristic and combustion oscillation of the combustor is recorded, and
that a relation of the current state of operation of the gas turbine corresponding to the category of the fuel characteristic is determined based on the history,
wherein said at least four categories are classified into a small category, a slightly small category, a slightly large category and a large category in accordance with the preset thresholds.
2. The gas turbine control device according to claim 1 , wherein
the state grasping unit checks the current state of operation of the gas turbine on the basis of the result of the frequency analysis split into the plurality of respective frequency bands from the frequency analyzing unit and the process value of the gas turbine from the inputting unit,
that the state grasping unit determines a relation of an amount of correction in the current state of operation of the gas turbine corresponding to the category of the fuel characteristic determined by the fuel characteristic estimating unit on the basis of the history indicating the relation between the category of the fuel characteristic and combustion oscillation of the combustor, and
that the state grasping unit corrects the checked current state of operation on the basis of the category of the fuel characteristic determined by the fuel characteristic estimating unit.
3. The gas turbine control device according to claim 1 , wherein a ratio between an output of the gas turbine and the fuel flow rate of the fuel is corrected by use of a deterioration characteristic of the gas turbine.
4. The gas turbine control device according to claim 1 , further comprising:
a combustion characteristic grasping unit for finding a relational expression indicating a combustion characteristic of the combustor from the current state of operation of the gas turbine checked by the state grasping unit on the basis of the category of the fuel characteristic determined by the fuel characteristic estimating unit,
wherein the countermeasure determining unit determines the increase or decrease in the flow rate of at least one of the fuel flow rate and the air flow rate to the combustor by use of the relational expression indicating the combustion characteristic of the combustor.