Gas turbine combustor, gas turbine, control device, and control method

1. A gas turbine combustor comprising:

an injection nozzle that can inject fuel and cooling air for cooling a pilot nozzle tip;

an air flow-rate adjuster that can adjust a flow rate of the cooling air to be supplied to the injection nozzle;

a detector that detects a combustion state of the fuel;

a controller configured to control the air flow-rate adjuster based on a detection result of the detector;

a pilot burner having therein a pilot nozzle comprising the pilot nozzle tip, the pilot nozzle being arranged at a center of the gas turbine combustor; and

a plurality of main burners respectively having therein a main nozzle arranged around the pilot burner, wherein

the controller increases the flow rate of the cooling air when a forming position of a circulating flow formed opposite to the injection nozzle is close to the injection nozzle relative to a reference position, and the controller decreases the flow rate of the cooling air when the forming position of the circulating flow is away from the injection nozzle relative to the reference position.

2. The gas turbine combustor according to claim 1 , further comprising a cooling-air supply flow channel connected to the injection nozzle to supply the cooling air toward the injection nozzle, wherein

the air flow-rate adjuster has a flow regulating valve provided in the cooling-air supply flow channel.

3. The gas turbine combustor according to claim 1 , further comprising a cooling-air supply flow channel connected to the injection nozzle to supply the cooling air toward the injection nozzle, wherein

the air flow-rate adjuster has a compressor that supplies the cooling air toward the cooling-air supply flow channel.

4. The gas turbine combustor according to claim 1 , wherein

the injection nozzle includes

a plurality of internal flow channels formed therein from a nozzle base end side to a pilot nozzle tip side, through which the fuel and the cooling air can circulate respectively,

the plurality of internal flow channels include

a first fuel flow channel through which the fuel circulates toward the pilot nozzle tip,

a second fuel flow channel through which the fuel circulates toward the pilot nozzle tip, and

a cooling flow channel through which the cooling air circulates toward the pilot nozzle tip, and

the cooling flow channel is provided between the first fuel flow channel and the second fuel flow channel in a direction from an internal side toward an external side of the injection nozzle.

5. The gas turbine combustor according to claim 1 , wherein

the injection nozzle includes

a plurality of internal flow channels formed therein from a nozzle base end side to a pilot nozzle tip side, through which the fuel and the cooling air can circulate respectively,

a contraction portion formed by narrowing down a part of at least one of the internal flow channels,

a manifold formed on an apical end side of the contraction portion to communicate with the internal flow channel, and

an injection hole that communicates with the manifold, wherein

one part of the plurality of internal flow channels is a cooling flow channel through which the cooling air circulates toward the pilot nozzle tip side.

6. The gas turbine combustor according to claim 5 , wherein

the injection nozzle includes

a nozzle body provided to extend from the nozzle base end side toward the pilot nozzle tip side, and

a plurality of swirler vanes arranged and provided around the nozzle body with a predetermined gap therebetween, and

in the plurality of internal flow channels, the cooling flow channel, which is the part of the internal flow channels, is provided to extend from the nozzle base end side toward the pilot nozzle tip side, and

a fuel flow channel through which the fuel circulates, which is the other part of the internal flow channels, is provided to extend from the nozzle base end side toward the swirler vanes.

7. The gas turbine combustor according to claim 5 , wherein the injection nozzle includes a nozzle body provided to extend from the nozzle base end side toward the pilot nozzle tip side, and a film-air flow channel formed around the nozzle body, through which film air circulates from the nozzle base end side toward the pilot nozzle tip side.

8. The gas turbine combustor according to claim 7 , wherein the film-air flow channel communicates with an external flow channel formed outside of the nozzle body.

9. The gas turbine combustor according to claim 7 , wherein one part of the plurality of internal flow channels is the film-air flow channel provided to extend from the nozzle base end side toward the pilot nozzle tip side.

10. The gas turbine combustor according to claim 7 , wherein the cooling flow channel is provided inside of the injection nozzle with respect to the film-air flow channel.

11. A gas turbine comprising:

the gas turbine combustor according to claim 1 , and

a turbine that is rotated by combustion gas generated by combusting the fuel in the gas turbine combustor.

12. The gas turbine combustor according to claim 1 , wherein the detector is a pressure sensor that detects pressure fluctuations in a combustor inner cylinder in which the injection nozzle is arranged, and

the controller adjusts the flow rate of the cooling air based on the pressure fluctuations detected by the pressure sensor.

13. The gas turbine combustor according to claim 1 , wherein the detector is a temperature sensor that detects the temperature of members that changes depending on the combustion state of the fuel, and

the controller increases the flow rate of the cooling air when the temperature detected by the temperature sensor is higher than a preset temperature.

14. A controller for a gas turbine combustor that includes an injection nozzle that can inject fuel and cooling air for cooling a pilot nozzle tip, an air flow-rate adjuster that can adjust a flow rate of the cooling air to be supplied to the injection nozzle, a detector that detects a combustion state of the fuel, a pilot burner having therein a pilot nozzle comprising the pilot nozzle tip, the pilot nozzle being arranged at a center of the gas turbine combustor, and a plurality of main burners respectively having therein a main nozzle arranged around the pilot burner, wherein

the controller is configured to control the air flow-rate adjuster based on a detection result of the detector, and increase the flow rate of the cooling air when a forming position of a circulating flow formed opposite to the injection nozzle is close to the injection nozzle relative to a reference position, and decrease the flow rate of the cooling air when the forming position of the circulating flow is away from the injection nozzle relative to the reference position.

15. A control method for a gas turbine combustor that includes an injection nozzle that can inject fuel and cooling air for cooling a pilot nozzle tip, an air flow-rate adjuster that can adjust a flow rate of the cooling air to be supplied to the injection nozzle, and a detector that detects a combustion state of the fuel, a pilot burner having therein a pilot nozzle comprising the pilot nozzle tip, the pilot nozzle being arranged at a center of the gas turbine combustor, a plurality of main burners respectively having therein a main nozzle arranged around the pilot burner, wherein the control method comprises:

controlling the air flow-rate adjuster with a controller configured to control the air flow-rate adjuster based on a detection result of the detector, wherein the flow rate of the cooling air is increased when a forming position of a circulating flow formed opposite to the injection nozzle is close to the injection nozzle relative to a reference position, and the flow rate of the cooling air is decreased when the forming position of the circulating flow is away from the injection nozzle relative to the reference position.