Control method for gas turbine plant, control device performing the method, and control program causing computer to perform the method

Abstract

To accurately grasp whether or not a fuel stably burns to stably burn the fuel.SOLUTION: A control method for a gas turbine plant performs: a fuel flow volume estimation step of estimating flow volume of fuel flowing into a combustor; an air flow volume estimation step of estimating flow volume of air flowing into the combustor; a combustion oscillation determination step of determining whether oscillation of internal pressure inside a cylinder in which fuel can be combusted, becomes a combustion oscillation occurrence state; a corrected flow volume ratio calculation step of calculating a corrected flow volume ratio that is a flow volume ratio enabling avoidance of g the combustion oscillation occurrence state, when it is determined that the combustion oscillation occurrence state occurs; a burner fuel-air ratio calculation step of calculating a first fuel-air ratio of the flow volume of a first fuel to the flow volume of a first air, and a second fuel-air ratio of the flow volume of a second fuel to the flow volume of a second air; and a stable combustion determination step of determining whether each of the first fuel-air ratio and the second fuel-air ratio is a fuel-air ratio within a stable combustion region where there is no possibility of misfire or backfire.SELECTED DRAWING: Figure 15

Description

[Technical field]

[0001] The present disclosure relates to a control method for a gas turbine plant including a gas turbine, a control device that executes the method, and a control program that causes a computer to execute the method. [Background technology]

[0002] A gas turbine includes a compressor capable of compressing air to generate compressed air, a combustor capable of burning fuel in the compressed air from the compressor to generate combustion gas, and a turbine capable of being driven by the combustion gas. The compressor has a compressor rotor, a compressor casing that covers the compressor rotor, and an intake air regulator. The intake air regulator is provided at the suction port of the compressor casing and regulates the flow rate of air sucked into the compressor casing. A generator rotor is connected to the compressor rotor.

[0003] The following Patent Document 1 discloses a technique for stably burning fuel in a combustor. The combustor of a gas turbine described in Patent Document 1 has a cylinder in which fuel can be burned, a plurality of main burners, and a pilot burner. The main burner has a main nozzle and a main air passage frame. The main nozzle is capable of injecting main fuel, which is a part of the fuel that has flowed into the combustor. The main air passage frame is a passage through which main air, which is a part of the compressed air that has flowed into the combustor, flows, and is capable of injecting the main fuel and the main air from the main nozzle into the cylinder. The pilot burner has a pilot nozzle and a pilot air passage frame. The pilot nozzle is capable of injecting pilot fuel, which is another part of the fuel that has flowed into the combustor. The pilot air passage frame is a passage through which pilot air, which is another part of the compressed air that has flowed into the combustor, flows, and is capable of injecting pilot fuel and pilot air from the pilot nozzle into the cylinder.

[0004] This Patent Document 1 describes that in order to achieve stable combustion of fuel, a limit is set on the fuel-air ratio, which is the ratio of the total flow rate of fuel flowing into the combustor to the total flow rate of compressed air flowing into the combustor.Furthermore, this Patent Document 1 also describes that in order to achieve stable combustion of fuel, a pilot ratio, which is the ratio of the flow rate of pilot fuel to the total flow rate of fuel flowing into the combustor, is appropriately corrected. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2009-203943 A Summary of the Invention [Problem to be solved by the invention]

[0006] In recent years, the operating environment of gas turbines has become more severe due to requests for operational changes in gas turbines, environmental issues, etc. As the operating environment of gas turbines becomes more severe, it is necessary to accurately grasp whether or not the fuel is burning stably while suppressing combustion oscillations in the combustor.

[0007] Therefore, an object of the present disclosure is to provide a technology that can suppress combustion oscillations in a combustor, while determining with high accuracy whether or not fuel is burning stably, thereby enabling the fuel to be burned stably. [Means for solving the problem]

[0008] A control method for a gas turbine plant as one aspect for achieving the above object is a control method applied to the following gas turbine plant. This gas turbine plant includes a gas turbine having an intake duct through which air can flow, a compressor capable of compressing the air from the intake duct to generate compressed air, a combustor capable of burning fuel in the compressed air to generate combustion gas, and a turbine capable of being driven by the combustion gas, a first fuel control valve capable of adjusting a flow rate of a first fuel which is a part of the fuel supplied to the combustor, and a second fuel control valve capable of adjusting a flow rate of a second fuel which is another part of the fuel supplied to the combustor. The compressor has a compressor rotor which can rotate about a rotor axis, a compressor casing which covers the compressor rotor, and an intake air amount regulator capable of adjusting the flow rate of air flowing into the compressor casing. The intake air amount regulator has a plurality of inlet guide vanes and a driver capable of changing the opening degree of the plurality of inlet guide vanes. The combustor includes a cylinder in which the fuel can be combusted, a first nozzle capable of injecting the first fuel, a first air flow path frame through which first air, which is a part of the compressed air flowing into the combustor, and the first fuel from the first nozzle can flow, a second nozzle capable of injecting the second fuel, and a second air flow path frame through which second air, which is another part of the compressed air flowing into the combustor, and the second fuel from the second nozzle can flow. This gas turbine plant control method includes a fuel flow rate estimating step of estimating a fuel flow rate of fuel actually flowing into the combustor, an air flow rate estimating step of estimating an air flow rate of the compressed air actually flowing into the combustor, a combustion oscillation determination step of determining whether or not a combustion oscillation occurrence state has occurred in which an internal pressure fluctuation in the cylinder is greater than a predetermined value, and if it is determined in the combustion oscillation determination step that the combustion oscillation occurrence state has occurred, a corrected flow rate ratio calculation step of calculating a corrected flow rate ratio which is a flow rate ratio capable of avoiding the combustion oscillation occurrence state by using relationship data between an increase / decrease in combustion oscillation and an increase / decrease in a flow rate ratio of the flow rate of the first fuel with respect to a flow rate of the fuel supplied to the combustor, and a burner fuel-air ratio calculation step of determining a first fuel-air ratio which is a ratio of the flow rate of the first fuel to a flow rate of the second air, and a second fuel-air ratio which is a ratio of the flow rate of the second fuel to a flow rate of the second air; a stable combustion determination step of determining whether each of the first fuel-air ratio and the second fuel-air ratio is a fuel-air ratio within a predetermined stable combustion region in which there is no possibility of misfire or backfire; and an instruction step of instructing the first fuel control valve and the second fuel control valve so that a flow rate ratio of the flow rate of the first fuel to a flow rate of fuel supplied to the combustor becomes the corrected flow rate ratio when it is determined in the stable combustion determination step that both the first fuel-air ratio and the second fuel-air ratio are within the stable combustion region. The fuel flow rate estimated in the fuel flow rate estimation step is the flow rate of fuel flowing into the combustor, which is determined based on an intake air temperature, which is the temperature of the air flowing into the compressor casing, an IGV opening, which is the opening of the multiple inlet guide vanes, and a GT output, which is the output of the gas turbine. The air flow rate estimated in the air flow rate estimation step is the flow rate of the compressed air flowing into the combustor, which is determined based on the intake air temperature, the IGV opening, and the GT output. In the burner fuel-air ratio calculation step, the flow rate of the first fuel and the flow rate of the second fuel are calculated using the corrected flow rate ratio and the fuel flow rate estimated in the fuel flow rate estimation step, and the flow rate of the first air and the flow rate of the second air are calculated using a predetermined air flow rate ratio between the flow rate of the first air flowing through the first air flow path frame and the flow rate of the second air flowing through the second air flow path frame and the air flow rate estimated in the air flow rate estimation step.

[0009] In this aspect, in the combustion oscillation determination step, it is determined whether or not the combustion oscillation occurs in a state where the internal pressure fluctuation in the cylinder is greater than a predetermined value. If it is determined in this combustion oscillation determination step that the combustion oscillation occurs, in the corrected flow rate ratio calculation step, a corrected flow rate ratio that is a flow rate ratio that can avoid the combustion oscillation occurs is calculated. In the burner fuel-air ratio calculation step, a first fuel-air ratio that is a ratio of the flow rate of the first fuel to the flow rate of the first air, and a second fuel-air ratio that is a ratio of the flow rate of the second fuel to the flow rate of the second air are calculated. That is, in the burner fuel-air ratio calculation step, a fuel-air ratio in a first burner having a first nozzle and a first air passage frame, and a fuel-air ratio in a second burner having a second nozzle and a second air passage frame are calculated. In the burner fuel-air ratio calculation step, the fuel flow rate of the fuel that actually flows into the combustor, which is estimated in the fuel flow rate estimation step, and the air flow rate of the compressed air that actually flows into the combustor, which is estimated in the air flow rate estimation step, are used to calculate the fuel-air ratio for each burner. In the stable combustion determination step, it is determined whether the fuel-air ratio for each burner is within a predetermined stable combustion region in which there is no possibility of misfire or backfire. Therefore, in this aspect, it is possible to grasp with high accuracy whether the fuel will burn stably.

[0010] When the stable combustion judgment process determines that the fuel-air ratio for each burner is within a predetermined stable combustion region in which there is no possibility of misfire or backfire, the instruction process instructs the first fuel control valve and the second fuel control valve so that the flow rate ratio of the flow rate of the first fuel to the flow rate of the fuel supplied to the combustor becomes a corrected flow rate ratio.

[0011] Therefore, in this aspect, it is possible to suppress combustion oscillations in the combustor, while determining with high accuracy whether or not the fuel will burn stably, thereby enabling the fuel to be burned stably.

[0012] A control device for a gas turbine plant as one aspect for achieving the above object is a control device that is applied to the following gas turbine plant. This gas turbine plant includes a gas turbine having an intake duct through which air can flow, a compressor capable of compressing the air from the intake duct to generate compressed air, a combustor capable of burning fuel in the compressed air to generate combustion gas, and a turbine capable of being driven by the combustion gas, a first fuel control valve capable of adjusting a flow rate of a first fuel which is a part of the fuel supplied to the combustor, and a second fuel control valve capable of adjusting a flow rate of a second fuel which is another part of the fuel supplied to the combustor. The compressor has a compressor rotor which can rotate about a rotor axis, a compressor casing which covers the compressor rotor, and an intake air amount regulator capable of adjusting the flow rate of air flowing into the compressor casing. The intake air amount regulator has a plurality of inlet guide vanes and a driver capable of changing the opening degree of the plurality of inlet guide vanes. The combustor includes a cylinder in which the fuel can be combusted, a first nozzle capable of injecting the first fuel, a first air flow path frame through which first air, which is a part of the compressed air flowing into the combustor, and the first fuel from the first nozzle can flow, a second nozzle capable of injecting the second fuel, and a second air flow path frame through which second air, which is another part of the compressed air flowing into the combustor, and the second fuel from the second nozzle can flow. The control device for the gas turbine plant includes a fuel flow rate estimator that estimates a fuel flow rate of fuel actually flowing into the combustor, an air flow rate estimator that estimates an air flow rate of the compressed air actually flowing into the combustor, a combustion oscillation determiner that determines whether or not a combustion oscillation occurrence state has occurred in which an internal pressure fluctuation in the cylinder is greater than a predetermined value, a relationship data memory that stores relationship data between an increase / decrease in combustion oscillation and an increase / decrease in a flow rate ratio of the flow rate of the first fuel with respect to the flow rate of the fuel supplied to the combustor, and, when the combustion oscillation determiner determines that the combustion oscillation occurrence state has occurred, a corrected flow rate ratio that is a flow rate ratio that can avoid the combustion oscillation occurrence state, using the relationship data stored in the relationship data memory. a burner fuel-air ratio calculator for calculating a first fuel-air ratio which is a ratio of a flow rate of the first fuel to a flow rate of the first air, and a second fuel-air ratio which is a ratio of a flow rate of the second fuel to a flow rate of the second air; a stable combustion determiner for determining whether each of the first fuel-air ratio and the second fuel-air ratio is a fuel-air ratio within a predetermined stable combustion region in which there is no possibility of misfire or backfire; and an indicator for instructing the first fuel control valve and the second fuel control valve so that a flow rate ratio of the flow rate of the first fuel to a flow rate of fuel supplied to the combustor becomes the corrected flow rate ratio when the stable combustion determiner determines that both the first fuel-air ratio and the second fuel-air ratio are fuel-air ratios within the stable combustion region. The fuel flow rate estimated by the fuel flow rate estimator is the flow rate of fuel flowing into the combustor, which is determined based on an intake air temperature, which is the temperature of the air flowing into the compressor casing, an IGV opening, which is the opening of the multiple inlet guide vanes, and a GT output, which is the output of the gas turbine. The air flow rate estimated by the air flow rate estimator is the flow rate of the compressed air flowing into the combustor, which is determined based on the intake air temperature, the IGV opening, and the GT output. The burner fuel-air ratio calculator determines the flow rate of the first fuel and the flow rate of the second fuel using the corrected flow rate ratio and the fuel flow rate estimated by the fuel flow rate estimator, and determines the flow rate of the first air and the flow rate of the second air using a predetermined air flow rate ratio between the flow rate of the first air flowing through the first air flow path frame and the flow rate of the second air flowing through the second air flow path frame and the air flow rate estimated by the air flow rate estimator.

[0013] In the present aspect, similarly to the control method of the above aspect, it is possible to suppress combustion oscillations in the combustor while determining with high accuracy whether or not the fuel is burning stably, thereby enabling the fuel to be burned stably.

[0014] A control program for a gas turbine plant as one aspect for achieving the above object is a control program applied to the following gas turbine plant. This gas turbine plant includes a gas turbine having an intake duct through which air can flow, a compressor capable of compressing the air from the intake duct to generate compressed air, a combustor capable of burning fuel in the compressed air to generate combustion gas, and a turbine capable of being driven by the combustion gas, a first fuel control valve capable of adjusting a flow rate of a first fuel which is a part of the fuel supplied to the combustor, and a second fuel control valve capable of adjusting a flow rate of a second fuel which is another part of the fuel supplied to the combustor. The compressor has a compressor rotor which can rotate about a rotor axis, a compressor casing which covers the compressor rotor, and an intake air amount regulator capable of adjusting the flow rate of air flowing into the compressor casing. The intake air amount regulator has a plurality of inlet guide vanes and a driver capable of changing the opening degree of the plurality of inlet guide vanes. The combustor includes a cylinder in which the fuel can be combusted, a first nozzle capable of injecting the first fuel, a first air flow path frame through which first air, which is a part of the compressed air flowing into the combustor, and the first fuel from the first nozzle can flow, a second nozzle capable of injecting the second fuel, and a second air flow path frame through which second air, which is another part of the compressed air flowing into the combustor, and the second fuel from the second nozzle can flow. The control program for the gas turbine plant includes a fuel flow rate estimating step of estimating a fuel flow rate of fuel actually flowing into the combustor, an air flow rate estimating step of estimating an air flow rate of the compressed air actually flowing into the combustor, a combustion oscillation determination step of determining whether or not a combustion oscillation occurrence state has occurred in which an internal pressure fluctuation in the cylinder is greater than a predetermined value, and if it is determined in the combustion oscillation determination step that the combustion oscillation occurrence state has occurred, a corrected flow rate ratio calculation step of calculating a corrected flow rate ratio which is a flow rate ratio capable of avoiding the combustion oscillation occurrence state by using relationship data between an increase / decrease in combustion oscillation and an increase / decrease in a flow rate ratio of the flow rate of the first fuel with respect to a flow rate of the fuel supplied to the combustor, and The method causes a computer to execute a burner fuel-air ratio calculation step of determining a first fuel-air ratio which is a ratio of a flow rate of the first fuel to a flow rate of the second air, and a second fuel-air ratio which is a ratio of a flow rate of the second fuel to a flow rate of the second air; a stable combustion determination step of determining whether each of the first fuel-air ratio and the second fuel-air ratio is a fuel-air ratio within a predetermined stable combustion region in which there is no possibility of misfire or backfire; and an instruction step of instructing the first fuel control valve and the second fuel control valve so that a flow rate ratio of the flow rate of the first fuel to a flow rate of fuel supplied to the combustor becomes the corrected flow rate ratio when it is determined in the stable combustion determination step that both the first fuel-air ratio and the second fuel-air ratio are within the stable combustion region. The fuel flow rate estimated in the fuel flow rate estimation step is the flow rate of fuel flowing into the combustor, which is determined based on an intake air temperature, which is the temperature of the air flowing into the compressor casing, an IGV opening, which is the opening of the multiple inlet guide vanes, and a GT output, which is the output of the gas turbine. The air flow rate estimated in the air flow rate estimation step is the flow rate of the compressed air flowing into the combustor, which is determined based on the intake air temperature, the IGV opening, and the GT output. In the burner fuel-air ratio calculation step, the flow rate of the first fuel and the flow rate of the second fuel are calculated using the corrected flow rate ratio and the fuel flow rate estimated in the fuel flow rate estimation step, and the flow rate of the first air and the flow rate of the second air are calculated using a predetermined air flow rate ratio between the flow rate of the first air flowing through the first air flow path frame and the flow rate of the second air flowing through the second air flow path frame and the air flow rate estimated in the air flow rate estimation step.

[0015] By having a computer execute the control program of this aspect, as in the control method of the above aspect, it is possible to suppress combustion oscillations in the combustor, while determining with high accuracy whether or not the fuel is burning stably, thereby enabling the fuel to be burned stably. Effect of the Invention

[0016] According to one aspect of the present disclosure, it is possible to suppress combustion oscillations in a combustor, while determining with high accuracy whether or not fuel will burn stably, thereby enabling the fuel to be burned stably. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a schematic configuration diagram of a gas turbine plant according to an embodiment of the present disclosure. [Diagram 2] 1 is a cross-sectional view of a combustor in one embodiment according to the present disclosure. [Diagram 3] FIG. 2 is an explanatory diagram illustrating a hardware configuration of a control device according to an embodiment of the present disclosure. [Figure 4] FIG. 2 is a functional block diagram of a control device according to an embodiment of the present disclosure. [Diagram 5] 1 is a graph showing a relationship between a GT output and an IGV opening degree in an embodiment according to the present disclosure. [Figure 6] 1 is a graph showing a relationship between a combustion load command CLCSO and a pilot ratio PLr in an embodiment according to the present disclosure. [Figure 7] FIG. 2 is a functional block diagram of a fuel flow droplet in one embodiment according to the present disclosure. [Figure 8] 1 is a graph showing the relationship between GT output and fuel ratio K in one embodiment of the present disclosure. [Figure 9] FIG. 2 is a functional block diagram of an airflow estimator in one embodiment according to the present disclosure. [Figure 10] 1 is a graph showing a relationship between an IGV opening degree and a past air ratio δp in an embodiment according to the present disclosure. [Figure 11] 1 is a graph showing a relationship between a pilot burner outlet flow velocity and an upper limit value of a pilot fuel-air ratio in an embodiment according to the present disclosure. [Figure 12] 11 is a graph showing a relationship between a main burner outlet flow velocity and an upper limit value of a main fuel-air ratio in an embodiment according to the present disclosure. [Figure 13] 4 is a graph showing a relationship between a main fuel-air ratio and a lower limit value of a pilot fuel-air ratio in an embodiment according to the present disclosure. [Figure 14] 5 is a flowchart illustrating an operation of a control device in one embodiment according to the present disclosure. [Figure 15] 4 is a flowchart illustrating an operation of a flow ratio regulator in one embodiment according to the present disclosure. [Figure 16] 4 is a flowchart illustrating the operation of a fuel flow estimator in one embodiment according to the present disclosure. [Figure 17] 4 is a flow chart illustrating the operation of an airflow estimator in one embodiment of the present disclosure. [Figure 18] FIG. 1 is an explanatory diagram for explaining the relationship between a basic fuel flow rate, an actual fuel flow rate, and a GT output at the past and estimated times in an embodiment according to the present disclosure, using actual numerical examples. [Figure 19]FIG. 11 is an explanatory diagram for explaining the relationship between a basic air flow rate, an actual air flow rate, and an IGV opening degree at the past and estimated times in an embodiment according to the present disclosure, using actual numerical examples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, an embodiment of a gas turbine plant control method, a control device for executing this method, and a control program for causing a computer to execute this method according to the present invention will be described with reference to the drawings.

[0019] As shown in FIG. 1, the gas turbine plant of this embodiment includes a gas turbine 1, a fuel supply system 40 capable of supplying fuel F to the gas turbine 1, and a control device 100 for controlling these.

[0020] The gas turbine 1 has an intake duct 3 through which air A can flow, an intermediate casing 4, a compressor 10 capable of compressing the air A from the intake duct 3 to generate compressed air Acom, a combustor 20 capable of burning fuel F in the compressed air Acom to generate combustion gas CG, and a turbine 30 that can be driven by the combustion gas CG.

[0021] The compressor 10 has a compressor rotor 11 rotatable about a rotor axis Ar, a compressor casing 14 covering the compressor rotor 11, a plurality of compressor stator vane rows 15, and an intake air regulator 16. The turbine 30 has a turbine rotor 31 rotatable about a rotor axis Ar, a turbine casing 34 rotatably covering the turbine rotor 31, and a plurality of turbine stator vane rows 35. The compressor rotor 11 and the turbine rotor 31 are connected to each other so as to be rotatable together to form a gas turbine rotor 2. A rotor of a generator GEN is connected to the gas turbine rotor 2. The generator GEN is provided with a power meter 50 that detects the amount of electric power generated by the generator GEN, in other words, the output (GT output) PW of the gas turbine 1. In the following description, the direction in which the rotor axis Ar extends is the rotor axial direction Da, one side in the rotor axial direction Da is the axial upstream side Dau, and the other side in the rotor axial direction Da is the axial downstream side Dad.

[0022] The compressor 10 is disposed on the axial upstream side Dau with respect to the turbine 30. The compressor rotor 11 has a compressor rotor shaft 12 extending in the rotor axial direction Da centered on the rotor axis Ar, and a plurality of compressor rotor blade rows 13 attached to the compressor rotor shaft 12. The plurality of compressor rotor blade rows 13 are arranged in the rotor axial direction Da. Each compressor rotor blade row 13 is composed of a plurality of rotor blades arranged in the circumferential direction with respect to the rotor axis Ar. On the axial downstream side Dad of each of the plurality of compressor rotor blade rows 13, one of the plurality of compressor stator vane rows 15 is disposed. Each compressor stator vane row 15 is attached inside the compressor casing 14. Each compressor stator vane row 15 is composed of a plurality of stator vanes arranged in the circumferential direction with respect to the rotor axis Ar. The intake air regulator 16 has a plurality of inlet guide vanes (IGVs) 17 and a driver 18 that can change the direction of each IGV 17. The plurality of IGVs 17 are disposed on the axial upstream side Dau of the plurality of compressor rotor blade rows 13.

[0023] The intake duct 3 is connected to an end Dau on the axial upstream side of the compressor casing 14. The intake duct 3 is provided with an intake pressure differential meter 51 for detecting an intake pressure difference ΔPi which is the pressure difference of air A between two points in the intake duct 3, an intake pressure meter 52 for detecting an intake pressure Pi which is the pressure of air A in the intake duct 3, and an intake temperature meter 53 for detecting an intake temperature Ti which is the temperature of air A in the intake duct 3.

[0024] The turbine rotor 31 has a turbine rotor shaft 32 extending in the rotor axial direction Da centered on the rotor axis Ar, and a plurality of turbine rotor blade rows 33 attached to the turbine rotor shaft 32. The plurality of turbine rotor blade rows 33 are aligned in the rotor axial direction Da. Each turbine rotor blade row 33 is composed of a plurality of rotor blades aligned in the circumferential direction about the rotor axis Ar. On the axial upstream side Dau of each of the plurality of turbine rotor blade rows 33, one of the plurality of turbine stator blade rows 35 is disposed. Each turbine stator blade row 35 is attached inside the turbine casing 34. Each turbine stator blade row 35 is composed of a plurality of stator blades aligned in the circumferential direction about the rotor axis Ar.

[0025] The intermediate casing 4 is disposed between the compressor casing 14 and the turbine casing 34 in the rotor axial direction Da. An end on the axial upstream side Dau of the intermediate casing 4 is connected to an end on the axial downstream side Dad of the compressor casing 14. An end on the axial downstream side Dad of the intermediate casing 4 is connected to an end on the axial upstream side Dau of the turbine casing 34. Compressed air Acom discharged from the compressor 10 flows into the intermediate casing 4.

[0026] The combustor 20 is attached to the intermediate casing 4. As shown in Fig. 2, the combustor 20 includes an outer cylinder 21 fixed to the intermediate casing 4, a base plate 22, an inner cylinder 23 arranged on the inner circumferential side of the outer cylinder 21, a plurality of burners 25a, 25b arranged on the inner circumferential side of the inner cylinder 23, and a combustion cylinder (or transition piece) 28 in which fuel F injected from the burners 25a, 25b can be combusted on the inner circumferential side.

[0027] The external cylinder 21, the inner cylinder 23, and the combustion cylinder 28 are all cylindrically shaped around the combustor axis Ac. The base plate 22 extends in a radial direction relative to the combustor axis Ac. The external cylinder 21 is disposed on the tip side Dct of the base plate 22, out of the tip side Dct and the base side Dcb in the combustor axial direction Dc in which the combustor axis Ac extends, and is fixed to the base plate 22. A portion formed by the base plate 22 and the external cylinder 21 is sometimes called a top hat due to its shape. The inner cylinder 23 is disposed on the tip side Dct of the base plate 22 and is fixed to the base plate 22 via a support or the like. The combustion cylinder 28 is connected to the tip side Dct of the inner cylinder 23. The inner cylinder 23 or the combustion cylinder 28 is provided with an internal pressure fluctuation meter 57 that detects internal pressure fluctuations. The internal pressure fluctuation meter 57 may be any type of instrument as long as it can detect internal pressure fluctuations of the inner cylinder 23 or the combustion cylinder 28. For example, the internal pressure fluctuation meter 57 may be a vibration meter that indirectly detects the internal pressure fluctuation of the inner cylinder 23 or the combustion cylinder 28.

[0028] Of the burners 25a and 25b, one burner 25a constitutes a pilot burner (first burner) 25a, and the remaining burners 25b constitute a main burner (second burner) 25b. The pilot burner 25a has a pilot nozzle (first nozzle) 26a capable of injecting pilot fuel (first fuel) Fp, and a pilot air passage frame (first air passage frame) 27a through which pilot air (first air) Ap flows and capable of injecting the pilot air Ap together with the pilot fuel Fp into the combustion tube 28. The main burner 25b has a main nozzle (second nozzle) 26b capable of injecting main fuel (second fuel) Fm, and a main air passage frame (second air passage frame) 27b through which main air (second air) Am flows and capable of injecting the main air Am together with the main fuel Fm into the combustion tube 28.

[0029] The pilot air (first air) Ap is a part of the compressed air Acom that is discharged from the compressor 10 and flows into the combustor 20 through the intermediate casing 4. The main air (second air) Am is another part of the compressed air Acom that is discharged from the compressor 10 and flows into the combustor 20 through the intermediate casing 4.

[0030] The fuel supply system 40 includes a fuel line 41, a pilot fuel line (first fuel line) 43a, a main fuel line (second fuel line) 43b, a pilot fuel control valve (first fuel control valve) 44a, and a main fuel control valve (second fuel control valve) 44b. The fuel line 41 allows the fuel F to be supplied to the combustor 20 to flow therethrough. The pilot fuel line 43a and the main fuel line 43b are connected to the fuel line 41. The pilot fuel line 43a is connected to the pilot nozzle 26a. The pilot fuel line 43a allows the pilot fuel Fp, which is a part of the fuel F from the fuel line 41, to flow therethrough. The pilot fuel control valve 44a can adjust the flow rate of the pilot fuel Fp flowing through the pilot fuel line 43a. The main fuel line 43b is connected to a plurality of main nozzles 26b. The main fuel line 43b allows the main fuel Fm, which is another part of the fuel F from the fuel line 41, to flow therethrough. The main fuel control valve 44b is capable of adjusting the flow rate of the pilot fuel Fp flowing through the main fuel line 43b.

[0031] The fuel line 41 is provided with a fuel pressure gauge 55 for detecting a fuel pressure Pf, which is the pressure of the fuel F in the fuel line 41, and a fuel thermometer 56 for detecting a fuel temperature Tf, which is the temperature of the fuel F in the fuel line 41. The pilot fuel line 43a is provided with a pilot fuel pressure differential gauge 54a for detecting a pilot fuel pressure difference ΔPp, which is the pressure difference of the pilot fuel Fp before and after the pilot fuel control valve 44a. The main fuel line 43b is provided with a main fuel pressure differential gauge 54b for detecting a main fuel pressure difference ΔPm, which is the pressure difference of the main fuel Fp before and after the main fuel control valve 44b.

[0032] 3, the control device 100 has a computer main body 101, an input device 109k such as a keyboard and a mouse, and a display device 109d. The computer main body 101 has a CPU (Central Processing Unit) 102 that performs various calculations, a main storage device 103 such as a memory that serves as a work area for the CPU 102, an auxiliary storage device 104 such as a hard disk drive device, an input / output interface 105 for the input device and the display device, a storage / playback device 106 that performs storage processing and playback processing of data on a disk-type storage medium D, a device interface 107, and a communication interface 108 for communicating with the outside via a network N.

[0033] The device interface 107 is connected to the instruments described above, the fuel control valves 42a, 42b, and the intake air regulator 16 via signal lines and the like.

[0034] The auxiliary storage device 104 has a control program 104p and the like prestored therein. A flow rate ratio adjustment program 104pa is incorporated into this control program 104p. The control program 104p is loaded into the auxiliary storage device 104 from a disk-type storage medium D via the storage / playback device 106, for example. The control program 104p may also be loaded into the auxiliary storage device 104 from an external device via the communication interface 108.

[0035] 4, the control device 100 functionally includes a fuel flow command generator 110, an IGV command generator 111, a combustion load command generator 112, a load corresponding flow ratio calculator 113, a flow ratio adjuster 120, and an indicator 150. All of these functional elements function when the CPU 102 executes a control program 104p stored in the auxiliary storage device 104. The flow ratio adjuster 120 functions when the CPU 102 executes a flow ratio adjustment program 104pa incorporated in the control program 104p.

[0036] The fuel flow rate command generator 110 generates a fuel flow rate command CSO. This fuel flow rate command CSO indicates the total flow rate of the fuel F supplied to the combustor 20. Therefore, the fuel flow rate command generator 110 calculates a fuel flow rate, which is the total flow rate of the fuel F supplied to the combustor 20. The GT output PW detected by the power meter 50 and a required output PWr from the outside to the gas turbine 1 are input to this fuel flow rate command generator 110. The fuel flow rate command generator 110 determines the fuel flow rate according to the deviation between the GT output PW and the required output PWr, and generates a fuel flow rate command CSO indicating this fuel flow rate.

[0037] The IGV command generator 111 generates an IGV command IGVc indicating the IGV opening. The GT output PW detected by the power meter 50 and the intake air temperature Ti detected by the intake air temperature meter 53 are input to the IGV command generator 111. The IGV command generator 111 has a function F1 indicating the relationship between the GT output PW and the IGV opening. As shown in FIG. 5, this function F1 is a function in which the IGV opening gradually increases as the GT output PW increases. The IGV command generator 111 uses this function F1 to determine the IGV opening corresponding to the GT output PW. The IGV command generator 111 corrects this IGV opening with the intake air temperature Ti. Then, the IGV command generator 111 generates an IGV command IGVc indicating the corrected IGV opening. Note that here, the relationship between the GT output PW and the IGV opening is defined by the function F1, but this relationship may be defined by a map.

[0038] The combustion load command generator 112 generates a combustion load command CLCSO. This combustion load command CLCSO is a parameter that non-dimensionalizes the temperature of the combustion gas CG at the inlet of the turbine 30 (hereinafter referred to as the inlet temperature), and is a parameter that has a positive correlation with this inlet temperature. The combustion load command CLCSO is set to 0% when the inlet temperature is at its lower limit and to 100% when the inlet temperature is at its upper limit. For example, when the lower limit of the inlet temperature is 700°C and the upper limit of the inlet temperature is 1500°C, the combustion load command CLCSO (%) is expressed by the following formula.

[0039] CLCSO(%)={(actual measured value of GT output PW - 700℃MW) / (1500℃MW-700℃MW)}×100 Note that 700°C MW is the GT output PW when the inlet temperature is at the lower limit of 700°C, and 1500°C MW is the GT output PW when the inlet temperature is at the upper limit of 1500°C.

[0040] The combustion load command generator 112 receives as input the GT output PW detected by the power meter 50, the intake air temperature Ti detected by the intake air temperature meter 53, and the IGV command IGVc generated by the IGV command generator 111. The combustion load command generator 112 has a function F2 that indicates the relationship between the intake air temperature Ti, the IGV command IGVc, and the GT output PW700°CMW. The combustion load command generator 112 uses this function F2 to determine the GT output PW700°CMW that corresponds to the intake air temperature Ti detected by the intake air temperature meter 53 and the IGV command IGVCIGV17c generated by the IGV command generator 111. The combustion load command generator 112 also has a function F3 that indicates the relationship between the intake air temperature Ti, the IGV command IGVc, and the GT output PW1500°CMW. The combustion load command generator 112 uses this function F3 to determine the GT output PW1500°CMW corresponding to the intake temperature Ti detected by the intake temperature meter 53 and the IGV command IGVc generated by the IGV command generator 111. The combustion load command generator 112 creates and generates the combustion load command CLCSO using the GT output PW700°CMW and GT output PW1500°CMW determined as described above, and the GT output PW detected by the output meter 50.

[0041] In the above, the lower limit value of the inlet temperature of the combustion gas CG in the turbine 30 is set to 700°C and the upper limit value thereof is set to 1500°C, but the lower limit value and the upper limit value of the inlet temperature may be set to values ​​different from those in the above example depending on the model of the combustor 20, etc. Also, here, the relationship between the intake air temperature Ti, the IGV command IGVc, and the GT output PW700°CMW is defined by function F2, and the relationship between the intake air temperature Ti, the IGV command IGVc, and the GT output PW1500°CMW is defined by function F3, but these relationships may be defined by a map.

[0042] The load corresponding flow ratio calculator 113 calculates the load corresponding flow ratio. In this embodiment, the load corresponding flow ratio is calculated as a pilot ratio PLr, which is the ratio of the flow rate of the pilot fuel (first fuel) Fp to the total fuel flow rate flowing into the combustor 20. The main ratio Mr, which is the ratio of the flow rate of the main fuel Fm to the total fuel flow rate flowing into the combustor 20, is calculated by (1-PLr). The load corresponding flow ratio calculator 113 has a function F4 that indicates the relationship between the combustion load command CLCSO and the pilot ratio PLr. As shown in FIG. 6, this function F4 is a function that gradually decreases the pilot ratio PLr as the combustion load command CLCSO increases, that is, as the inlet temperature of the combustion gas CG increases. The load corresponding flow ratio calculator 113 receives the combustion load command CLCSO from the combustion load command generator 112, and calculates the pilot ratio PLr corresponding to this combustion load command CLCSO using the function F4. Although the relationship between the combustion load command CLCSO and the pilot ratio PLr is defined by the function F4 here, this relationship may be defined by a map.

[0043] The indicator 150 has a fuel valve indicator 151 and an IGV indicator 152. The fuel valve indicator 151 receives a fuel flow command CSO from the fuel flow command generator 110 and a pilot ratio PLr as a load corresponding flow ratio from the load corresponding flow ratio calculator 113. The fuel valve indicator 151 determines a valve opening degree of the pilot fuel control valve (first fuel control valve) 44a such that the flow rate of the pilot fuel supplied to the pilot nozzle 26a becomes a flow rate determined by the total fuel flow rate indicated by the fuel flow command CSO and the pilot ratio PLr as the load corresponding flow ratio. Then, the fuel valve indicator 151 sends a valve opening degree command PLVc indicating the valve opening degree of the pilot fuel control valve 44a to the pilot fuel control valve 44a. Furthermore, the fuel valve indicator 151 determines the valve opening of the main fuel control valve (second fuel control valve) 44b such that the flow rate of the main fuel supplied to the main nozzle 26b becomes a flow rate determined by the total fuel flow rate indicated by the fuel flow rate command CSO and the main ratio (1-PLr) as the load corresponding flow rate ratio. Then, the fuel valve indicator 151 sends a valve opening command MVc indicating the valve opening of the main fuel control valve 44b to the main fuel control valve 44b. When the pilot fuel control valve 44a receives this valve opening command PLVc, the valve opening is set to the valve opening indicated by this valve opening command PLVc. When the main fuel control valve 44b receives this valve opening command MVc, the valve opening is set to the valve opening indicated by this valve opening command MVc. The IGV indicator 152 receives the IGV command IGVc from the IGV command generator 111 and sends this IGV command IGVc to the intake air regulator 16. As a result, the multiple IGVs 17 in the intake air regulator 16 have the IGV opening degrees indicated by this IGV command IGVc.

[0044] The flow ratio adjuster 120 has a fuel flow estimator 121, an air flow estimator 131, a combustion oscillation judger 140, a corrected flow ratio calculator 141, a burner fuel-air ratio calculator 142, a stable combustion judger 143, a relationship data memory 144, and the above-mentioned fuel valve indicator 151.

[0045] The fuel flow rate estimator 121 estimates a fuel flow rate Gf which is the mass flow rate of the fuel F that actually flows into the combustor 20. As shown in Fig. 7, the fuel flow rate estimator 121 has an estimation actual fuel flow rate calculation unit 122, a fuel ratio calculation unit 123, and a fuel flow rate calculation unit 124. The functions and operations of the estimation actual fuel flow rate calculation unit 122, the fuel ratio calculation unit 123, and the fuel flow rate calculation unit 124 will be described in detail later.

[0046] The air flow rate estimator 131 estimates an air flow rate Ga, which is the mass flow rate of the compressed air Acom that actually flows into the combustor 20. As shown in Fig. 9, the air flow rate estimator 131 has a basic air flow rate calculation unit 132, an estimated actual air flow rate calculation unit 133, an estimated air ratio calculation unit 134, a past air ratio calculation unit 135, and an air flow rate calculation unit 136. The functions and operations of the basic air flow rate calculation unit 132, the estimated actual air flow rate calculation unit 133, the estimated air ratio calculation unit 134, the past air ratio calculation unit 135, and the air flow rate calculation unit 136 will be described in detail later.

[0047] As shown in Fig. 4, the combustion oscillation judger 140 receives an input of the internal pressure fluctuation value (internal pressure amplitude) of the inner cylinder 23 or the combustion cylinder 28 from the internal pressure fluctuation meter 57. The combustion oscillation judger 140 judges whether or not a combustion oscillation occurrence state has occurred in which the internal pressure fluctuation value (internal pressure amplitude) of the inner cylinder 23 or the combustion cylinder 28 is greater than a predetermined value. Note that the combustion oscillation occurrence state here does not mean a state in which the combustor 20 will be damaged within a short period of time if the internal pressure fluctuation value detected by the internal pressure fluctuation meter 57 continues, but a state in which the possibility of the combustor 20 being damaged increases if the internal pressure fluctuation value detected by the internal pressure fluctuation meter 57 becomes even higher.

[0048] The relationship data storage unit 144 stores relationship data relating to an increase or decrease in the combustion oscillation and an increase or decrease in a flow rate ratio (pilot ratio PLr) of the flow rate Fp of the pilot fuel (first fuel) to the flow rate of the fuel supplied to the combustor 20.

[0049] When the combustion oscillation determiner 140 determines that the combustion oscillation is occurring, the corrected flow ratio calculator 141 uses the relationship data stored in the relationship data memory 144 to determine a corrected flow ratio (corrected pilot ratio PLr), which is a flow ratio that can avoid the combustion oscillation occurrence state.

[0050] The burner fuel-air ratio calculator 142 calculates a pilot fuel-air ratio (first fuel-air ratio) P·F / A, which is the ratio of the flow rate of pilot fuel (first fuel) Fp to the flow rate of pilot air (first air) Ap, and a main fuel-air ratio (second fuel-air ratio) M·F / A, which is the ratio of the flow rate of main fuel (second fuel) Fm to the flow rate of main air (second air) Am. That is, the burner fuel-air ratio calculator 142 calculates the fuel-air ratio for each of the multiple burners 25a, 25b.

[0051] The burner fuel-air ratio calculator 142 calculates the flow rate of the pilot fuel Fp and the flow rate of the main fuel Fm using the corrected flow rate ratio (corrected pilot ratio PLr) calculated by the corrected flow rate ratio calculator 141 and the fuel flow rate Gf estimated by the fuel flow rate estimator 121. The burner fuel-air ratio calculator 142 calculates the corrected main ratio (1-PLr) using the corrected pilot ratio PLr, and calculates the flow rate of the main fuel Fm using this corrected main ratio (1-PLr) and the fuel flow rate Gf estimated by the fuel flow rate estimator 121. The burner fuel-air ratio calculator 142 also calculates the flow rates of the pilot air Ap and the main air Am using a predetermined flow rate ratio between the flow rate of the pilot air Ap flowing through the pilot air flow path frame (first air flow path frame) 27a and the flow rate of the main air Am flowing through the main air flow path frame (second air flow path frame) 27b, and the air flow rate Ga estimated by the air flow rate estimator 131.

[0052] The stable combustion determiner 143 determines whether the pilot fuel-air ratio (first fuel-air ratio) P·F / A and the main fuel-air ratio (second fuel-air ratio) M·F / A are each within a predetermined stable combustion region. The stable combustion determiner 143 has functions F5, F6, and F7 that indicate the relationship between the pilot fuel-air ratio P·F / A and the main fuel-air ratio M·F / A and the limit of the stable combustion region.

[0053] 11, function F5 is a function that indicates the relationship between the outlet flow velocity of the main burner 25b and the upper limit of the main fuel-air ratio M·F / A at which the flame formed from the main fuel Fm ejected from the main burner 25b into the combustion tube 28 does not flash back. The stable combustion determiner 143 determines the outlet flow velocity of the main burner 25b from the flow rate of the main air Am determined by the burner fuel-air ratio calculator 142 and the cross-sectional area of ​​the main air flow path frame 27b. If the main fuel-air ratio M·F / Aa calculated by the burner fuel-air ratio calculator 142 is greater than the upper limit of the main fuel-air ratio M·F / A for the outlet flow velocity of the main burner 25b, the stable combustion determiner 143 determines that the flame formed of the main fuel Fm injected from the main burner 25b into the combustion tube 28 will backfire, that is, the main fuel-air ratio M·F / Aa calculated by the burner fuel-air ratio calculator 142 is not a fuel-air ratio in the stable combustion region.

[0054] 12, function F6 is a function that indicates the relationship between the outlet flow velocity of the pilot burner 25a and the upper limit value of the pilot fuel-air ratio P·F / A at which the flame formed from the pilot fuel Fp injected from the pilot burner 25a into the combustion tube 28 does not flash back. The stable combustion determiner 143 determines the outlet flow velocity of the pilot burner 25a from the flow rate of the pilot air Ap determined by the burner fuel-air ratio calculator 142 and the cross-sectional area of ​​the pilot air flow path frame 27a. If the pilot fuel-air ratio P·F / Aa calculated by the burner fuel-air ratio calculator 142 is greater than the upper limit of the pilot fuel-air ratio P·F / A for the outlet flow velocity of the pilot burner 25a, the stable combustion determiner 143 determines that the flame formed from the pilot fuel Fp injected from the pilot burner 25a into the combustion tube 28 will flash back, that is, that the pilot fuel-air ratio P·F / Aa calculated by the burner fuel-air ratio calculator 142 is not a fuel-air ratio in the stable combustion region.

[0055] 13, function F7 is a function that indicates the relationship between the main fuel-air ratio M·F / A and the lower limit value of the pilot fuel-air ratio P·F / A at which the flame in the combustion tube 28 does not misfire. If the pilot fuel-air ratio P·F / Aa calculated by the burner fuel-air ratio calculator 142 is smaller than the lower limit value of the pilot fuel-air ratio P·F / A for the main fuel-air ratio M·F / Aa calculated by the burner fuel-air ratio calculator 142, the stable combustion determiner 143 determines that the flame in the combustion tube 28 will misfire, that is, that the pilot fuel-air ratio P·F / Aa and the main fuel-air ratio M·F / Aa calculated by the burner fuel-air ratio calculator 142 are not fuel-air ratios in the stable combustion region.

[0056] When the stable combustion judgement unit 143 judges that at least one of the pilot fuel-air ratio P·F / A and the main fuel-air ratio M·F / A calculated by the burner fuel-air ratio calculator 142 is not within the stable combustion region, the corrected flow ratio calculator 141 calculates a corrected flow ratio (corrected pilot ratio PLr) which is a flow ratio at which each of the pilot fuel-air ratio P·F / A and the main fuel-air ratio M·F / A becomes a fuel-air ratio within the stable combustion region.

[0057] For example, as shown in Fig. 11, the main fuel-air ratio M·F / Aa calculated by the burner fuel-air ratio calculator 142 is larger than the upper limit of the main fuel-air ratio M·F / A for the outlet flow velocity of the main burner 25b, and the stable combustion judger 143 judges that the flame formed by the main fuel Fm ejected from the main burner 25b into the combustion tube 28 will flash back. In this case, the corrected flow ratio calculator 141 further corrects the corrected flow ratio (corrected pilot ratio PLr) according to a predetermined rule so that the main fuel-air ratio M·F / A becomes a value M·F / Ab smaller than the upper limit. As a result of this correction, the pilot fuel-air ratio P·F / A and the main fuel-air ratio M·F / A change. Therefore, the stable combustion judger 143 judges whether the pilot fuel-air ratio P·F / A and the main fuel-air ratio M·F / A after the change are fuel-air ratios within the stable combustion region. If the pilot fuel-air ratio P·F / A and the main fuel-air ratio M·F / A after the change are fuel-air ratios within the stable combustion region, the stable combustion judger 143 sends the corrected corrected flow ratio (corrected pilot ratio PLr) to the fuel valve indicator 151. If the stable combustion judger 143 judges again that the pilot fuel-air ratio P·F / A after the change is not a fuel-air ratio within the stable combustion region, the corrected flow ratio calculator 141 further corrects the corrected flow ratio (corrected pilot ratio PLr). That is, the corrected flow ratio calculator 141 repeatedly calculates the corrected flow ratio (corrected pilot ratio PLr) until the pilot fuel-air ratio P·F / A and the main fuel-air ratio M·F / A determined by the corrected flow ratio (corrected pilot ratio PLr) become a fuel-air ratio within the stable combustion region. The stable combustion judger 143 sends the corrected flow ratio (corrected pilot ratio PLr) corresponding to the fuel-air ratio judged to be within the stable combustion region to the fuel valve indicator 151.

[0058] Also, for example, as shown in Fig. 12, it is assumed that the pilot fuel-air ratio P·F / Aa calculated by the burner fuel-air ratio calculator 142 is greater than the upper limit value of the pilot fuel-air ratio P·F / A for the outlet flow velocity of the pilot burner 25a, and the stable combustion judger 143 judges that the flame formed by the pilot fuel Fp ejected from the pilot burner 25a into the combustion tube 28 will flash back. In this case, the corrected flow ratio calculator 141 further corrects the corrected flow ratio (corrected pilot ratio PLr) according to a predetermined rule so that the pilot fuel-air ratio P·F / A becomes a value P·F / Ab smaller than the upper limit value. As a result of this correction, the pilot fuel-air ratio P·F / A and the main fuel-air ratio M·F / A change. Therefore, the stable combustion judger 143 judges whether the pilot fuel-air ratio P·F / A and the main fuel-air ratio M·F / A after the change are fuel-air ratios within the stable combustion region. If the pilot fuel-air ratio P·F / A and the main fuel-air ratio M·F / A after the change are fuel-air ratios within the stable combustion region, the stable combustion judger 143 sends the corrected corrected flow ratio (corrected pilot ratio PLr) to the fuel valve indicator 151. If the stable combustion judger 143 judges again that the pilot fuel-air ratio P·F / A after the change is not a fuel-air ratio within the stable combustion region, the corrected flow ratio calculator 141 further corrects the corrected flow ratio (corrected pilot ratio PLr). That is, the corrected flow ratio calculator 141 repeatedly calculates the corrected flow ratio (corrected pilot ratio PLr) until the pilot fuel-air ratio P·F / A and the main fuel-air ratio M·F / A determined by the corrected flow ratio (corrected pilot ratio PLr) become a fuel-air ratio within the stable combustion region. The stable combustion judger 143 sends the corrected flow ratio (corrected pilot ratio PLr) corresponding to the fuel-air ratio judged to be within the stable combustion region to the fuel valve indicator 151.

[0059] Also, for example, as shown in Fig. 13, it is assumed that the pilot fuel-air ratio P·F / Aa calculated by the burner fuel-air ratio calculator 142 is smaller than the lower limit value of the pilot fuel-air ratio P·F / A relative to the main fuel-air ratio M·F / Aa calculated by the burner fuel-air ratio calculator 142, and the stable combustion judger 143 judges that the flame in the combustion tube 28 will misfire. In this case, the corrected flow rate ratio calculator 141 further corrects the corrected flow rate ratio (corrected pilot ratio PLr) according to a predetermined rule so that the pilot fuel-air ratio P·F / A becomes a value P·F / Ab larger than the lower limit value. As a result of this correction, the pilot fuel-air ratio P·F / A and the main fuel-air ratio M·F / A change. Therefore, the stable combustion judger 143 judges whether the pilot fuel-air ratio P·F / A and the main fuel-air ratio M·F / A after the change are fuel-air ratios within the stable combustion region. If the pilot fuel-air ratio P·F / A and the main fuel-air ratio M·F / A after the change are fuel-air ratios within the stable combustion region, the stable combustion judger 143 sends the corrected corrected flow ratio (corrected pilot ratio PLr) to the fuel valve indicator 151. If the stable combustion judger 143 judges again that the pilot fuel-air ratio P·F / A after the change is not a fuel-air ratio within the stable combustion region, the corrected flow ratio calculator 141 further corrects the corrected flow ratio (corrected pilot ratio PLr). That is, the corrected flow ratio calculator 141 repeatedly calculates the corrected flow ratio (corrected pilot ratio PLr) until the pilot fuel-air ratio P·F / A and the main fuel-air ratio M·F / A determined by the corrected flow ratio (corrected pilot ratio PLr) become a fuel-air ratio within the stable combustion region. The stable combustion judger 143 sends the corrected flow ratio (corrected pilot ratio PLr) corresponding to the fuel-air ratio judged to be within the stable combustion region to the fuel valve indicator 151.

[0060] When the fuel valve indicator 151 receives the corrected flow rate ratio (corrected pilot ratio PLr) from the stable combustion determiner 143, it determines the valve opening of the pilot fuel control valve 44a from the total fuel flow rate indicated by the fuel flow rate command CSO and the corrected pilot ratio PLr. Furthermore, the fuel valve indicator 151 determines the valve opening of the main fuel control valve 44b from the total fuel flow rate indicated by the fuel flow rate command CSO and the corrected main ratio (1-PLr). Then, the fuel valve indicator 151 sends a valve opening command PLVc indicating the valve opening of the pilot fuel control valve 44a to the pilot fuel control valve 44a, and sends a valve opening command MVc indicating the valve opening of the main fuel control valve 44b to the main fuel control valve 44b.

[0061] Next, the basic operation of the control device 100 described above will be described with reference to the flowchart shown in FIG.

[0062] The fuel flow rate command generator 110 of the control device 100 generates a fuel flow rate command CSO indicating the total flow rate of the fuel F supplied to the combustor 20 in accordance with the deviation between the GT output PW detected by the power meter 50 and the required output PWr for the gas turbine 1 from the outside (fuel flow rate command generating step S1).

[0063] The IGV command generator 111 of the control device 100 determines the IGV opening based on the GT output PW detected by the power meter 50 and the intake temperature Ti detected by the intake temperature meter 53. Then, the IGV command generator 111 generates an IGV command IGVc indicating the IGV opening (IGV command generating step S2).

[0064] The combustion load command generator 112 of the control device 100 determines a combustion load command CLCSO, which is a parameter that non-dimensionalizes the inlet temperature of the turbine 30, based on the GT output PW detected by the power meter 50, the intake temperature Ti detected by the intake temperature meter 53, and the IGV command IGVc generated by the IGV command generator 111. Then, the combustion load command generator 112 generates this combustion load command CLCSO (combustion load command generating step S3).

[0065] The load corresponding flow ratio calculator 113 of the control device 100 determines the pilot ratio PLr as the load corresponding flow ratio based on the combustion load command CLCSO (load corresponding flow ratio calculation step S4).

[0066] The indicator 150 of the control device 100 sends an IGV command IGVc to the intake air regulator 16, sends a valve opening command PLVc to the pilot fuel control valve 44a, and sends a valve opening command MVc to the main fuel control valve 44b (command step S5).

[0067] Specifically, the IGV indicator 152 of the indicator 150 receives an IGV command IGVc indicating the IGV opening from the IGV command generator 111, and sends this IGV command IGVc to the intake air regulator 16. The intake air regulator 16 becomes the IGV opening indicated by this IGV command IGVc. The fuel valve indicator 151 of the indicator 150 receives a fuel flow command CSO from the fuel flow command generator 110 and a pilot ratio PLr as a load corresponding flow ratio from the load corresponding flow ratio calculator 113. The fuel valve indicator 151 determines the valve opening of the pilot fuel control valve (first fuel control valve) 44a such that the flow rate of pilot fuel supplied to the pilot nozzle 26a becomes a flow rate determined by the total fuel flow indicated by the fuel flow command CSO and the pilot ratio PLr as the load corresponding flow ratio. Then, the fuel valve indicator 151 sends a valve opening command PLVc indicating the valve opening of the pilot fuel control valve 44a to the pilot fuel control valve 44a. Furthermore, the fuel valve indicator 151 determines the valve opening of the main fuel control valve (second fuel control valve) 44b such that the flow rate of the main fuel supplied to the main nozzle 26b becomes a flow rate determined by the total fuel flow rate indicated by the fuel flow rate command CSO and the main ratio (1-PLr) as the load corresponding flow rate ratio. Then, the fuel valve indicator 151 sends a valve opening command MVc indicating the valve opening of the main fuel control valve 44b to the main fuel control valve 44b. When the pilot fuel control valve 44a receives this valve opening command PLVc, the valve opening is set to the valve opening indicated by this valve opening command PLVc. When the main fuel control valve 44b receives this valve opening command MVc, the valve opening is set to the valve opening indicated by this valve opening command MVc.

[0068] Next, the operation of the flow rate ratio regulator 120 in the control device 100 described above will be described with reference to the flowchart shown in FIG.

[0069] As described above, the combustion oscillation judger 140 receives the value of the internal pressure fluctuation (internal pressure amplitude) of the inner cylinder 23 or the combustion cylinder 28 from the internal pressure fluctuation meter 57. The combustion oscillation judger 140 judges whether or not the value of the internal pressure fluctuation (internal pressure amplitude) of the inner cylinder 23 or the combustion cylinder 28 is greater than a predetermined value, indicating that a combustion oscillation has occurred (combustion oscillation judgement step S10).

[0070] When it is determined in the combustion oscillation determination step S10 that the combustion oscillation is occurring, the corrected flow ratio calculator 141 calculates a corrected flow ratio (corrected pilot ratio PLr) that is a flow ratio that can avoid the combustion oscillation occurrence state (corrected flow ratio calculation step S11). At this time, as described above, the corrected flow ratio calculator 141 calculates the corrected pilot ratio PLr using relationship data between the increase / decrease in the combustion oscillation and the increase / decrease in the flow ratio (pilot ratio PLr) of the flow rate Fp of the pilot fuel (first fuel) to the flow rate of the fuel supplied to the combustor 20.

[0071] As described above, the fuel flow rate estimator 121 of the flow ratio regulator 120 estimates the fuel flow rate Gf, which is the mass flow rate of the fuel F that actually flows into the combustor 20 (fuel flow rate estimation step S12). The air flow rate estimator 131 of the flow ratio regulator 120 estimates the air flow rate Ga, which is the mass flow rate of the compressed air Acom that actually flows into the combustor 20 (air flow rate estimation step S13).

[0072] Before explaining the method of estimating the fuel flow rate Gf by the fuel flow rate estimator 121 and the method of estimating the air flow rate Ga by the air flow rate estimator 131, a basic fuel flow rate Gfb, a basic air flow rate Gab, an actual fuel flow rate Gfr, and an actual air flow rate Gar will be explained.

[0073] The basic fuel flow rate Gfb is the mass flow rate of the fuel F flowing into the combustor 20, which is determined by the intake temperature Ti, the IGV opening, and the GT output PW. The basic air flow rate Gab is the mass flow rate of the compressed air Acom flowing into the combustor 20, which is determined by the intake temperature Ti, the IGV opening, and the GT output PW.

[0074] The basic fuel flow rate Gfb and the basic air flow rate Gab are determined by executing the following processes (1) to (6).

[0075] (1) Using a compressor characteristic map, compressor operating conditions (intake temperature Ti, IGV opening, intake flow rate, compressor efficiency, etc.) are obtained for a number of predetermined pressure ratios.

[0076] (2) Assuming fuel flow rates for a plurality of predetermined GT output powers PW, the inlet temperature of the turbine 30 for each fuel flow rate for the plurality of GT output powers PW is calculated from the heat balance of the gas turbine 1.

[0077] (3) Based on the turbine inlet conditions and the turbine shape, etc., defined in (2), the expansion ratio of the turbine 30 is calculated for each turbine inlet condition.

[0078] (4) The process of (2) and the process of (3) are repeated until any one of a plurality of predetermined pressure ratios matches the expansion ratio of the turbine 30. When the pressure ratio and the expansion ratio match, the operating state of the gas turbine 1 at this pressure ratio is determined. The operating conditions include the intake temperature Ti, the IGV opening, the intake flow rate, the compressor efficiency, the inlet temperature of the turbine 30, the fuel flow rate, the GT output PW, the compressor driving force, and the output of the turbine 30 alone. The above process is executed for all the predetermined pressure ratios.

[0079] (5) A map is created that shows the operating state of the gas turbine 1 for each of a plurality of predetermined pressure ratios obtained by the above processes (1) to (4).

[0080] (6) By referring to the map, the fuel flow rate corresponding to the intake temperature Ti detected by the intake temperature gauge 53, the IGV opening indicated by the IGV command IGVc generated by the IGV command generator 111, and the GT output PW detected by the power meter 50 is determined. This fuel flow rate is the basic fuel flow rate Gfb. Furthermore, by referring to the map, the intake flow rate corresponding to the intake temperature Ti detected by the intake temperature gauge 53, the IGV opening indicated by the IGV command IGVc generated by the IGV command generator 111, and the GT output PW detected by the power meter 50 is determined. This intake flow rate is the basic air flow rate Gab. Note that, when a portion of the compressed air Acom discharged from the compressor 10 is used for cooling the turbine 30, the value obtained by subtracting the air flow rate for cooling the turbine 30 from the basic air flow rate Gab obtained by referring to the map becomes the basic air flow rate Gab to be actually handled.

[0081] At a past time, such as when the gas turbine 1 was started up, the multiple stator vanes and multiple rotor blades of the compressor 10 were not dirty, and therefore it is reliable that the basic air flow rate Gab determined by the intake temperature Ti, the IGV aperture, and the GT output PW is the flow rate of the compressed air Acom that actually flows into the combustor 20. Similarly, at a past time, such as when the gas turbine 1 was undergoing test operation, it is reliable that the basic fuel flow rate Gfb determined by the intake temperature Ti, the IGV aperture, and the GT output PW is the flow rate of the fuel F that actually flows into the combustor 20.

[0082] The actual air flow rate Gar is the mass flow rate of the air A flowing into the combustor 20. The actual fuel flow rate Gfr is the mass flow rate of the fuel F flowing into the combustor 20.

[0083] The mass flow rate of the air A flowing into the compressor 10 can be calculated from the intake pressure difference ΔPi detected by the intake pressure differential meter 51 and the cross-sectional area of ​​the intake duct 3. This mass flow rate of the air A is the actual air flow rate Gar. However, if the temperature or pressure of the air A flowing into the compressor 10 changes, the mass flow rate of the air A flowing into the compressor 10 changes. Therefore, in this embodiment, the mass flow rate of the air A is calculated using the intake pressure difference ΔPi detected by the intake pressure differential meter 51, the cross-sectional area of ​​the intake duct 3, the intake temperature Ti detected by the intake temperature meter 53, and the intake pressure Pi detected by the intake pressure meter 52, and this is set as the actual air flow rate Gar. Note that, when a part of the compressed air Acom discharged from the compressor 10 is used for cooling the turbine 30, the value obtained by subtracting the cooling air flow rate of the turbine 30 from the actual air flow rate Gar calculated from the intake pressure difference ΔPi, etc., becomes the actual air flow rate Gar to be actually handled.

[0084] The mass flow rate of the fuel F flowing into the combustor 20 is the sum of the mass flow rate of the pilot fuel Fp flowing through the pilot fuel line 43a and the mass flow rate of the pilot fuel Fp flowing through the main fuel line 43b. The mass flow rate of the pilot fuel Fp flowing through the pilot fuel line 43a can be calculated from the pilot fuel pressure difference ΔPp detected by the pilot fuel pressure differential meter 54a and the valve characteristics of the pilot fuel control valve (first fuel control valve) 44a. The mass flow rate of the pilot fuel Fp flowing through the main fuel line 43b can be calculated from the main fuel pressure difference ΔPm detected by the main fuel pressure differential meter 54b and the valve characteristics according to the valve opening of the main fuel control valve (second fuel control valve) 44b. This mass flow rate of the fuel F is the actual fuel flow rate Gfr. However, if the temperature or pressure of the fuel F flowing into the combustor 20 changes, the mass flow rate of the fuel F flowing into the combustor 20 changes accordingly. Therefore, in this embodiment, the mass flow rate of the fuel F is calculated using the pilot fuel pressure difference ΔPp, the valve characteristics of the pilot fuel control valve 44a, the main fuel pressure difference ΔPm, and the valve characteristics corresponding to the valve opening of the main fuel control valve 44b, as well as the fuel temperature Tf detected by the fuel thermometer 56 and the fuel pressure Pf detected by the fuel pressure gauge 55, and this is set as the actual fuel flow rate Gfr.

[0085] The actual air flow rate Gar obtained as described above is not reliable as an absolute value, but is reliable as a change trend of the actual air flow rate Gar associated with the aging of the gas turbine 1. Also, the actual fuel flow rate Gfr obtained as described above is not reliable as an absolute value, but is reliable as a change trend of the actual fuel flow rate Gfr associated with the aging of the gas turbine 1.

[0086] On the other hand, as described above, at a past time such as when the gas turbine 1 starts operating, the basic air flow rate Gab can be trusted to be the flow rate of the compressed air Acom that actually flows into the combustor 20. However, since the basic air flow rate Gab is not obtained using a parameter that changes with the time-dependent change of the gas turbine 1, it cannot be trusted to be the flow rate of the compressed air Acom that actually flows into the combustor 20 at the present time, in other words, at the time of estimating the air flow rate Ga. Similarly, at a past time such as when the gas turbine 1 starts operating, the basic fuel flow rate Gfb can be trusted to be the flow rate of the fuel F that actually flows into the combustor 20. However, since the basic fuel flow rate Gfb is not obtained using a parameter that changes with the time-dependent change of the gas turbine 1, it cannot be trusted to be the flow rate of the fuel F that actually flows into the combustor 20 at the present time, in other words, at the time of estimating the fuel flow rate Gf.

[0087] Therefore, as shown in the following formula (1), the air flow rate Ga flowing into the combustor 20 at the time of estimation is determined as a value obtained by multiplying the basic air flow rate Gab (=basic air flow rate Gab at the time of estimation) by the time-dependent change ratio αa of the actual air flow rate Gar from the past to the time of estimation. Also, as shown in the following formula (2), the fuel flow rate Gf flowing into the combustor 20 at the time of estimation is determined as a value obtained by multiplying the basic fuel flow rate Gfb (=basic fuel flow rate Gfb at the time of estimation) by the time-dependent change ratio αf of the actual fuel flow rate Gfr from the past to the time of estimation. As a result, the reliability of the value of the air flow rate Ga flowing into the combustor 20 at the time of estimation and the value of the fuel flow rate Gf flowing into the combustor 20 at the time of estimation obtained as described above is increased. Ga=Gab×αa ···············(1) Gf=Gfb×αf (2)

[0088] The ratio αa of change over time of the actual air flow rate Gar from the past time to the estimation time is the ratio of the estimated actual air flow rate Gaer, which is the actual air flow rate Gar at the time of estimation, to the past actual air flow rate Gapr, which is the actual air flow rate Gar at the time of estimation, as shown in the following formula (3). Also, the ratio αf of change over time of the actual fuel flow rate Gfr from the past time to the estimation time is the ratio of the estimated actual fuel flow rate Gfer, which is the actual fuel flow rate Gfr at the time of estimation, to the past actual fuel flow rate Gfr, which is the actual fuel flow rate Gfr at the time of estimation, as shown in the following formula (4). αa=Gaer / Gapr (3) αf=Gfer / Gfpr (4)

[0089] Hereinafter, a concept of calculating the air flow rate Ga flowing into the combustor 20 at the time of estimation and a concept of calculating the fuel flow rate Gf flowing into the combustor 20 at the time of estimation will be described by substituting specific numerical values ​​for each of the parameters described above.

[0090] 19, in the past, when the gas turbine 1 was operated with the IGV opening at the minimum opening IGVmin, the past actual air flow rate Gapr was 50 kg / s, and the basic air flow rate Gab determined under the same conditions was 60 kg / s. Also, in the estimation, when the gas turbine 1 was operated with the IGV opening at the minimum opening IGVmin, the estimated actual air flow rate Gaer was 40 kg / s, and the basic air flow rate Gab determined under the same conditions (=basic air flow rate Gab in the past) was 60 kg / s.

[0091] When the IGV opening is the minimum opening IGVmin, the time-dependent change ratio αa of the actual air flow rate Gar is 0.8, as shown below. αa=Gaer / Gapr =40(kg / s) / 50(kg / s)=0.80

[0092] Therefore, when the IGV opening is the minimum opening IGVmin, the estimated air flow rate Ga is 48 kg / s as shown below. Ga = Gab × αa = 60 (kg / s) × 0.80 = 48 (kg / s)

[0093] In addition, in the past, when the gas turbine 1 was operated with the IGV opening at the maximum opening IGVmax, the past actual air flow rate Gapr was 90 kg / s, and the basic air flow rate Gab determined under the same conditions was 100 kg / s. In addition, in the estimation, when the gas turbine 1 was operated with the IGV opening at the maximum opening IGVmax, the estimated actual air flow rate Gaer was 80 kg / s, and the basic air flow rate Gab determined under the same conditions (=basic air flow rate Gab in the past) was 100 kg / s.

[0094] When the IGV opening is at the maximum opening IGVmax, the time-dependent change ratio αa of the actual air flow rate Gar becomes 0.8, as shown below. αa=Gaer / Gapr =80(kg / s) / 90(kg / s)=0.89

[0095] Therefore, when the IGV opening is at the maximum opening IGVmax, the estimated air flow rate Ga is 89 kg / s as shown below. Ga = Gab × αa =100(kg / s)×0.89=89(kg / s)

[0096] 18, the past actual fuel flow rate when the gas turbine 1 was operated with the GT output PW at the minimum output (=no load) PWmin is set to 7.0 kg / s, and the basic fuel flow rate Gfb determined under the same conditions is set to 6.0 kg / s. Also, during estimation, the estimated actual fuel flow rate Gfer when the gas turbine 1 was operated with the GT output PW at the minimum output PWmin is set to 6.0 kg / s, and the basic fuel flow rate Gfb (=basic fuel flow rate Gfb in the past) determined under the same conditions is set to 6.0 kg / s.

[0097] When the GT output PW is the minimum output PWmin, the time-dependent change ratio αf of the actual fuel flow rate Gfr is 0.86, as shown below. αf=Gfer / Gfpr =6.0(kg / s) / 7.0(kg / s)=0.86

[0098] Therefore, when the GT output PW is the minimum output PWmin, the estimated fuel flow rate Gf is 5.1 kg / s as shown below. Gf = Gfb × αf = 6.0 (kg / s) × 0.86 = 5.1 (kg / s)

[0099] Also, in the past, when the gas turbine 1 was operated with the GT output PW at maximum output (= full load) PWmax, the past actual fuel flow rate was 9.0 kg / s, and the basic fuel flow rate Gfb determined under the same conditions was 10.0 kg / s. Also, in the estimation, when the gas turbine 1 was operated with the GT output PW at maximum output PWmax, the estimated actual fuel flow rate Gfer was 8.0 kg / s, and the basic fuel flow rate Gfb (= past basic fuel flow rate Gfb) determined under the same conditions was 10.0 kg / s.

[0100] When the GT output PW is the maximum output PWmax, the time-dependent change ratio αf of the actual fuel flow rate Gfr is 0.86, as shown below. αf=Gfer / Gfpr =8.0(kg / s) / 9.0(kg / s)=0.89

[0101] Therefore, when the GT output PW is the maximum output PWmax, the estimated fuel flow rate Gf is 8.9 kg / s as shown below. Gf = Gfb × αf = 10.0 (kg / s) × 0.89 = 8.9 (kg / s)

[0102] In this embodiment, the above formula (1) is transformed into the following formula (5), and the calculation shown in this formula (5) is performed to obtain the air flow rate Ga. In addition, in formula (5), the estimated air ratio δe is the ratio of the estimated actual air flow rate Gaer to the basic air flow rate Gab. Also, the past air ratio δp is the ratio of the past actual air flow rate Gapr to the basic air flow rate Gab. Ga = Gab × α = Gab × (Gaer / Gapr) =Gab×{(Gaer / Gab) / (Gapr / Gab)} =Gab×{(δe) / (δp)} ·········(5)

[0103] That is, the air flow rate estimator 131 in this embodiment multiplies the basic air flow rate Gab by the ratio of the air ratio δe at the time of estimation to the air ratio δp at the time of past to obtain the air flow rate Ga at the time of estimation.

[0104] Since the basic air flow rate Gab is a flow rate determined using the IGV opening as a parameter, as described with reference to FIG. 19, the data of the air flow rate changes with the change in the IGV opening. Therefore, all the variables (Gab, δp, δe) in the formula (5) also change with the change in the IGV opening. Therefore, when performing the calculation shown in the formula (5) to obtain the air flow rate Ga, it is necessary to unify all the variables (Gab, δp, δe) in the formula (5) to values ​​at the IGV opening at the time of estimation. Among all the variables (Gab, δp, δe) in the formula (5), the basic air flow rate Gab and the estimated air ratio δe are both determined based on data at the time of estimation, so that the basic air flow rate Gab at the estimated IGV opening and the estimated air ratio δe at the estimated IGV opening can be obtained. However, among all the variables (Gab, δp, δe) in the formula (5), the past air ratio δp is determined based on past data. For this reason, in order to obtain this past air ratio δp during estimation, past data for all IGV openings within the range from the minimum opening to the maximum opening must be stored in some form in a computer or the like.

[0105] In this embodiment, in order to obtain the past air ratio δp corresponding to the IGV opening at the time of estimation, a function F(IGV) that determines the past air ratio δp using the IGV opening as a variable is set in the past air ratio calculation unit 135 by an F(IGV) setter 138 (see FIG. 9). This function F(IGV) is the opening-past air ratio relationship.

[0106] This function F(IGV) is a function that indicates the relationship between the IGV opening and the past air ratio Δp, as shown in Fig. 10. This function F(IGV) is created by the F(IGV) setter 138 executing a relationship setting process shown in the following procedure.

[0107] First, the range in which the IGV opening can be changed, that is, the range from the minimum opening IGVmin to the maximum opening IGVmax, is divided into multiple ranges, and multiple divided ranges Rigv obtained by dividing this range into multiple ranges are determined. Next, for each of the multiple divided ranges Rigv, a representative point δpt related to the past air ratio δp is determined in a coordinate system in which the IGV opening and the past air ratio δp are variables. Then, on this coordinate system, the representative points δpt for each of the multiple divided ranges Rigv are mutually connected, and the function indicating the line obtained as a result is defined as function F(IGV). This function F(IGV) is the relationship between the opening and the past air ratio.

[0108] The representative point δpt for each of the multiple divided ranges Rigv is a point that represents the past air ratios δpa, δpb, δpc, ... for each of the multiple IGV openings in each divided range Rigv. Note that the representative point is, for example, the average value of the past air ratios δpa, δpb, δpc, ... for each of the multiple GT outputs PW. The past air ratios δpa, δpb, δpc, ... for each of the multiple IGV openings are obtained, for example, during a trial run of the gas turbine 1 immediately before the past (when the gas turbine 1 started operating).

[0109] In this embodiment, the above formula (2) is transformed into the following formula (6), and the calculation shown in this formula (6) is performed to obtain the fuel flow rate Gf. In the formula (6), the past fuel ratio K is the ratio of the basic fuel flow rate Gfb to the past actual fuel flow rate. Gf = Gfb × αf =Gfb × (Gfer / Gfpr) =Gfer × (Gab / Gfpr) = Gfer × K (6)

[0110] That is, the fuel flow rate estimator 121 in this embodiment multiplies the estimated actual fuel flow rate Gfer by the past fuel ratio K to obtain the estimated fuel flow rate Gf.

[0111] Since the basic fuel flow rate Gfb is a flow rate determined with the GT output PW as a parameter, as described with reference to FIG. 18, the fuel flow rate data changes with the change in the GT output PW. Therefore, all the variables (Gfer, K) in the formula (6) also change with the change in the GT output PW. Therefore, when performing the calculation shown in the formula (6) to obtain the fuel flow rate Gf, it is necessary to unify all the variables (Gfer, K) in the formula (6) to values ​​at the GT output PW at the time of estimation. Since the estimated actual fuel flow rate Gfer of all the variables (Gfer, K) in the formula (6) is determined based on the data at the time of estimation, it is possible to obtain the estimated actual fuel flow rate Gfer at the GT output PW at the time of estimation. However, the past fuel ratio K of all the variables (Gfer, K) in the formula (6) is determined based on the past data. Therefore, in order to obtain this past fuel ratio K at the time of estimation, it is necessary to store the past data for all the GT outputs PW within the range from the minimum output to the maximum output in some form in a computer or the like.

[0112] In this embodiment, in order to obtain the past fuel ratio K corresponding to the GT output PW at the time of estimation, a function F(PW) that determines the fuel ratio K using the GT output PW as a variable is set in the fuel ratio calculation section 123 by an F(PW) setter 128 (see FIG. 7). This function F(PW) is the output-fuel ratio past relationship.

[0113] This function F(PW), as shown in Fig. 8, is a function that indicates the relationship between the GT output PW and the fuel ratio K. This function F(PW) is created by the F(PW) setter 128 executing a relationship setting process shown in the following procedure.

[0114] First, the changeable range of the GT output PW, that is, the range from the minimum output (output at no load) PWmin to the maximum output (output at full load) PWmax, is divided into multiple ranges, and multiple divided ranges Rpw obtained by dividing this range into multiple ranges are determined. Next, for each of the multiple divided ranges Rpw, a representative point Kt related to the fuel ratio K is determined in a coordinate system in which the GT output PW and the fuel ratio K are variables. Then, on this coordinate system, the representative points Kt for each of the multiple divided ranges Rpw are mutually connected, and the function indicating the line obtained as a result is defined as the function F(PW).

[0115] The representative point Kt for each of the multiple divided ranges Rpw is a point that represents the past fuel ratios Ka, Kb, Kc, ... for each of the multiple GT outputs PW within each divided range Rpw. Note that the representative point is, for example, the average value of the past fuel ratios Ka, Kb, Kc, ... for each of the multiple GT outputs PW. The past fuel ratios Ka, Kb, Kc, ... for each of the multiple IGV openings are obtained, for example, during a test run of the gas turbine 1 immediately before the past (when the gas turbine 1 started operating).

[0116] In the fuel flow rate estimation step S12, as described above, the fuel flow rate estimator 121 estimates the fuel flow rate Gf, which is the mass flow rate of the fuel F that actually flows into the combustor 20, by using the equation (6).

[0117] As shown in the flowchart of FIG. 16, this fuel flow rate estimation step S12 includes an estimated actual fuel flow rate calculation step S121, a fuel ratio calculation step S122, and a fuel flow rate calculation step S123.

[0118] In an estimated actual fuel flow rate calculation step S121, the estimated actual fuel flow rate calculation unit 122 (see FIG. 7) of the fuel flow rate estimator 121 calculates the estimated actual fuel flow rate Gfer using the pilot fuel pressure difference ΔPp, the valve characteristics of the pilot fuel control valve 44a, the main fuel pressure difference ΔPm, the valve characteristics according to the valve opening of the main fuel control valve 44b, the fuel temperature Tf detected by the fuel temperature gauge 56, and the fuel pressure Pf detected by the fuel pressure gauge 55, as described above.

[0119] In the fuel ratio calculation step S122, the fuel ratio calculation unit 123 of the fuel flow rate estimator 121 uses the pre-stored function F(PW) described with reference to Fig. 8 to find the past fuel ratio K corresponding to the GT output PW at the time of estimation (current time) detected by the power meter 50. In this way, in this embodiment, by using the function F(PW), it is possible to easily find the past fuel ratio K for the GT output PW at the time of estimation at the past. The function F(PW) is set in the fuel ratio calculation unit 123 by the F(PW) setter 128.

[0120] In the fuel flow rate calculation step S123, the fuel flow rate calculation unit 124 of the fuel flow rate estimator 121 obtains the estimated fuel flow rate Gf by multiplying the estimated actual fuel flow rate Gfer by the past fuel ratio K, as explained using the formula (6). Since the formula (6) is a modified formula of the formula (2), the estimated fuel flow rate Gf can also be said to be a value obtained by multiplying the basic fuel flow rate Gfb by the fuel amount time-dependent change ratio αf, which is the ratio of the estimated actual fuel flow rate Gfer to the past actual fuel flow rate, as can be expressed by the formula (2).

[0121] In the air flow rate estimation step S13, as described above, the air flow rate estimator 131 estimates the air flow rate Ga, which is the mass flow rate of the air A that actually flows into the combustor 20, by using the equation (5).

[0122] As shown in the flowchart of FIG. 17, this air flow rate estimation process S13 includes an estimated actual air flow rate calculation process S131, a basic air flow rate calculation process S132, a past air ratio calculation process S133, an estimated air ratio calculation process S134, and an air flow rate calculation process S135.

[0123] In the estimated actual air flow rate calculation process S131, the estimated actual fuel flow rate calculation unit 122 (see Figure 9) of the air flow estimator 131 calculates the estimated actual air flow rate Gaer using the intake pressure difference ΔPi at the time of estimation (current time) detected by the intake pressure differential meter 51, the intake pressure Pi at the time of estimation (current time) detected by the intake pressure gauge 52, the intake temperature Ti at the time of estimation (current time) detected by the intake temperature meter 53, and the cross-sectional area of ​​the intake duct 3, as described above.

[0124] In the basic air flow rate calculation step S132, the basic air flow rate calculation unit 132 of the air flow rate estimator 131 uses a pre-stored map as described above to determine the basic air flow rate Gab corresponding to the intake temperature Ti at the time of estimation (current time) detected by the intake temperature meter 53, the IGV opening at the time of estimation (current time) indicated by the IGV command IGVc, and the GT output PW at the time of estimation (current time) detected by the power meter 50.

[0125] In the past air ratio calculation step S133, the past air ratio calculation unit 135 of the air flow rate estimator 131 calculates the past air ratio δp corresponding to the IGV opening at the time of estimation (current time) indicated by the IGV command IGVc, using the pre-stored function F(IGV) described with reference to Fig. 10. In this way, in this embodiment, by using the function F(IGV), it is possible to easily calculate the past air ratio δp for the IGV opening at the time of estimation in the past.

[0126] In the estimated air ratio calculation step S134, the estimated air ratio calculation unit 134 of the air flow estimator 131 divides the estimated actual air flow rate Gaer calculated in the estimated actual air flow rate calculation step S131 by the basic air flow rate Gab calculated in the basic air flow rate calculation step S132 to calculate the estimated air ratio δe.

[0127] In the air flow rate calculation step S135, the air flow rate calculation unit 136 of the air flow rate estimator 131 multiplies the basic air flow rate Gab by the ratio of the air ratio at estimation δe to the air ratio at past δp to obtain the air flow rate at estimation Ga, as explained using equation (5). Note that equation (5) is a modified equation of equation (1), so this air flow rate at estimation Ga can also be said to be a value obtained by multiplying the basic air flow rate Gab by the air flow rate temporal change ratio αa, which is the ratio of the actual air flow rate at estimation Gaer to the actual air flow rate at past Gapr, as can be expressed by equation (1).

[0128] The operation of the flow rate ratio regulator 120 will be described again with reference to the flowchart shown in FIG.

[0129] The burner fuel-air ratio calculator 142 calculates a pilot fuel-air ratio (first fuel-air ratio) P·F / A, which is the ratio of the flow rate of pilot fuel (first fuel) Fp to the flow rate of pilot air (first air) Ap, and a main fuel-air ratio (second fuel-air ratio) M·F / A, which is the ratio of the flow rate of main fuel (second fuel) Fm to the flow rate of main air (second air) Am. That is, the burner fuel-air ratio calculator 142 calculates the fuel-air ratio for each of the multiple burners 25a, 25b (burner fuel-air ratio calculation step S14).

[0130] At this time, when calculating the fuel-air ratio for each of the multiple burners 25a, 25b, the burner fuel-air ratio calculator 142 calculates the flow rate of the pilot fuel Fp and the flow rate of the main fuel Fm using the corrected flow rate ratio (corrected pilot ratio PLr) calculated by the corrected flow rate ratio calculator 141 and the fuel flow rate Gf estimated by the fuel flow rate estimator 121. The burner fuel-air ratio calculator 142 calculates the corrected main ratio (1-PLr) using the corrected pilot ratio PLr, and calculates the flow rate of the main fuel Fm using this corrected main ratio (1-PLr) and the fuel flow rate Gf estimated by the fuel flow rate estimator 121. In addition, the burner fuel-air ratio calculator 142 calculates the flow rate of pilot air Ap and the flow rate of main air Am using a predetermined flow rate ratio between the flow rate of pilot air Ap flowing through the pilot air flow path frame (first air flow path frame) 27a and the flow rate of main air Am flowing through the main air flow path frame (second air flow path frame) 27b, and the air flow rate Ga estimated by the air flow rate estimator 131.

[0131] As described above, the stable combustion determiner 143 of the flow ratio regulator 120 determines whether or not each of the pilot fuel-air ratio (first fuel-air ratio) P·F / A and the main fuel-air ratio (second fuel-air ratio) M·F / A is within a predetermined stable combustion region (stable combustion determination step S15).

[0132] Specifically, the stable combustion determiner 143 judges whether the main fuel-air ratio M·F / A obtained in the burner fuel-air ratio calculation step S14 is greater than the upper limit of the main fuel-air ratio M·F / A for the flow speed of the main burner 25b at the time of estimation (current time) by referring to the function F5 described above with reference to Fig. 11. If the main fuel-air ratio M·F / Aa obtained in the burner fuel-air ratio calculation step S14 is greater than the upper limit of the main fuel-air ratio M·F / A, the stable combustion determiner 143 judges that the flame formed by the main fuel Fm ejected from the main burner 25b into the combustion tube 28 flashes back, that is, the main fuel-air ratio M·F / A obtained in the burner fuel-air ratio calculation step S14 is not a fuel-air ratio in the stable combustion region.

[0133] 12, the stable combustion determiner 143 determines whether the pilot fuel-air ratio P·F / A obtained in the burner fuel-air ratio calculation step S14 is greater than the upper limit of the pilot fuel-air ratio P·F / A for the outlet flow velocity of the pilot burner 25a. If the pilot fuel-air ratio P·F / Aa obtained in the burner fuel-air ratio calculation step S14 is greater than the upper limit of the pilot fuel-air ratio P·F / A, the stable combustion determiner 143 determines that the flame formed by the pilot fuel Fp ejected from the pilot burner 25a into the combustion tube 28 flashes back, that is, the pilot fuel-air ratio P·F / A obtained in the burner fuel-air ratio calculation step S14 is not a fuel-air ratio in the stable combustion region.

[0134] 13, the stable combustion determiner 143 determines whether the pilot fuel-air ratio P·F / A calculated in the burner fuel-air ratio calculation step S14 is smaller than the lower limit value of the pilot fuel-air ratio P·F / A for the main fuel-air ratio M·F / A calculated in the burner fuel-air ratio calculation step S14. If the pilot fuel-air ratio P·F / Aa calculated in the burner fuel-air ratio calculation step S14 is smaller than the lower limit value of the pilot fuel-air ratio P·F / A for the main fuel-air ratio M·F / Aa calculated in the burner fuel-air ratio calculation step S14, the stable combustion determiner 143 determines that the flame in the combustion tube 28 will misfire, that is, the pilot fuel-air ratio P·F / A and the main fuel-air ratio M·F / A calculated in the burner fuel-air ratio calculation step S14 are not fuel-air ratios in the stable combustion region.

[0135] If it is determined in the stable combustion judgment step S15 that at least one of the pilot fuel-air ratio P·F / A and the main fuel-air ratio M·F / A calculated in the burner fuel-air ratio calculation step S14 is not within the stable combustion region, the corrected flow ratio calculator 141 of the flow ratio regulator 120 newly calculates the corrected flow ratio (corrected pilot ratio PLr) in accordance with the above-mentioned relationship data and predetermined rules, as described above with reference to Figures 11 to 13 (corrected flow ratio calculation step S11).

[0136] When the corrected flow ratio (corrected pilot ratio PLr) is calculated again in the corrected flow ratio calculation step S11, the pilot fuel-air ratio P·F / A and the main fuel-air ratio M·F / A at this corrected flow ratio are calculated in the burner fuel-air ratio calculation step S14. When the pilot fuel-air ratio P·F / A and the main fuel-air ratio M·F / A are calculated again in the burner fuel-air ratio calculation step S14, it is determined in the stable combustion determination step S15 whether or not each of the pilot fuel-air ratio (first fuel-air ratio) P·F / A and the main fuel-air ratio (second fuel-air ratio) M·F / A is a fuel-air ratio within a predetermined stable combustion region. Thereafter, the processes of S11, S14, and S15 are repeatedly executed until it is determined in the stable combustion determination step S15 that each of the pilot fuel-air ratio (first fuel-air ratio) P·F / A and the main fuel-air ratio (second fuel-air ratio) M·F / A is a fuel-air ratio within a predetermined stable combustion region.

[0137] In the stable combustion determination step S15, when it is determined that the pilot fuel-air ratio (first fuel-air ratio) P·F / A and the main fuel-air ratio (second fuel-air ratio) M·F / A are each within a predetermined stable combustion region, the fuel valve indicator prioritizes a corrected flow ratio (corrected pilot ratio PLr) over the load corresponding flow ratio calculated by the load corresponding flow ratio calculator 113, and calculates the valve opening of the pilot fuel control valve (first fuel control valve) 44a and the valve opening of the main fuel control valve (second fuel control valve) 44b based on this corrected flow ratio. In this case, the fuel valve indicator 151 calculates the valve opening of the pilot fuel control valve (first fuel control valve) 44a such that the flow rate of the pilot fuel supplied to the pilot nozzle 26a becomes a flow rate determined by the total fuel flow rate indicated by the fuel flow command CSO and the corrected pilot ratio PLr. Then, the fuel valve indicator 151 sends a valve opening command PLVc indicating the valve opening of the pilot fuel control valve 44a to the pilot fuel control valve 44a. Furthermore, the fuel valve indicator 151 determines the valve opening of the main fuel control valve (second fuel control valve) 44b such that the flow rate of the main fuel supplied to the main nozzle 26b becomes a flow rate determined by the total fuel flow rate indicated by the fuel flow rate command CSO and the corrected main ratio (1-PLr). Then, the fuel valve indicator 151 sends a valve opening command MVc indicating the valve opening of the main fuel control valve 44b to the main fuel control valve 44b. When the pilot fuel control valve 44a receives this valve opening command PLVc, the valve opening is set to the valve opening indicated by this valve opening command PLVc. When the main fuel control valve 44b receives this valve opening command MVc, the valve opening is set to the valve opening indicated by this valve opening command MVc.

[0138] In this embodiment, in the combustion oscillation judgment step S10, it is judged whether or not the internal pressure fluctuation in the cylinder 28 is greater than a predetermined value and the combustion oscillation occurs. If it is judged in this combustion oscillation judgment step S10 that the combustion oscillation occurs, a corrected flow rate ratio that is a flow rate ratio that can avoid the combustion oscillation occurs is calculated in the corrected flow rate ratio calculation step S11. In the burner fuel-air ratio calculation step S14, a first fuel-air ratio P·F / A that is the ratio of the flow rate of the first fuel Fp to the flow rate of the first air Ap, and a second fuel-air ratio M·F / A that is the ratio of the flow rate of the second fuel Fm to the flow rate of the second air Am are calculated. That is, in the burner fuel-air ratio calculation step S14, the fuel-air ratio in the first burner having the first nozzle 26a and the first air passage frame 27a, and the fuel-air ratio in the second burner having the second nozzle 26b and the second air passage frame 27b are calculated. In the burner fuel-air ratio calculation step S14, the fuel flow rate Gf of the fuel F that actually flows into the combustor 20, estimated in the fuel flow rate estimation step S12, and the air flow rate Ga of the compressed air Acom that actually flows into the combustor 20, estimated in the air flow rate estimation step S13, are used to obtain the fuel-air ratio for each burner. In the stable combustion determination step S15, it is determined whether the fuel-air ratio for each burner is within a predetermined stable combustion region in which there is no possibility of misfire or backfire. Therefore, in this embodiment, it is possible to grasp with high accuracy whether the fuel F will burn stably.

[0139] When it is determined in the stable combustion determination step S15 that the fuel-air ratio for each burner is within a predetermined stable combustion region in which there is no possibility of misfire or backfire, in the instruction step S16, an instruction is given to the first fuel control valve 44a and the second fuel control valve 44b so that the flow rate ratio of the flow rate of the first fuel Fp to the flow rate of the fuel F supplied to the combustor 20 becomes a corrected flow rate ratio.

[0140] Therefore, in this embodiment, it is possible to suppress the combustion oscillation in the combustor 20 while determining with high accuracy whether or not the fuel F will combust stably, thereby enabling the fuel F to be combusted stably.

[0141] In this embodiment, the fuel flow rate Gf and the air A / F flowing into the combustor 20 are values ​​that take into account changes over time, so that it is possible to determine a highly reliable pilot fuel / air ratio P·F / A and main fuel / air ratio M·F / A. In this embodiment, it is determined whether or not the pilot fuel / air ratio P·F / A and the main fuel / air ratio M·F / A are fuel / air ratios within the stable combustion region, so that the fuel F injected from each of the nozzles 26a, 26b can be stably combusted from this perspective as well.

[0142] "Variations" In the above embodiment, the actual air flow rate Gar is calculated using all of the intake pressure difference ΔPi, the intake pressure Pi, and the intake temperature Ti detected by the instruments. However, the actual air flow rate Gar may be calculated using only the intake pressure difference ΔPi among the data detected by the instruments. In the above embodiment, the actual fuel flow rate Gfr is calculated using the pilot fuel pressure difference ΔPp, the main fuel pressure difference ΔPm, the fuel temperature Tf, and the fuel pressure Pf detected by the instruments. However, the actual fuel flow rate Gfr may be calculated using only the pilot fuel pressure difference ΔPp and the main fuel pressure difference ΔPm among the data detected by the instruments.

[0143] When the period from the past to the estimation is short, the basic air flow rate Gab may be the air flow rate Ga that actually flows into the combustor 20. Furthermore, in this case, the basic fuel flow rate Gfb may be the fuel flow rate Gf that actually flows into the combustor 20.

[0144] As shown in Fig. 2, the combustor 20 includes a pilot nozzle 26a as a first nozzle, a main nozzle 26b as a second nozzle, and a top hat nozzle 26c as a third nozzle. A top hat fuel line 43c is connected to the top hat nozzle 26c. A fuel line 41 is connected to the top hat fuel line 43c. A top hat fuel control valve 44c is provided to the top hat fuel line 43c. The top hat nozzle 26c ejects top hat fuel as a third fuel into the compressed air passage between the external cylinder 21 and the inner cylinder 23. In this case, a third fuel-air ratio, which is a ratio between the top hat fuel and the third air, which is the compressed air Acom flowing in the third air passage frame formed by the external cylinder 21 and the inner cylinder 23, may be obtained, and it may be determined whether the third fuel-air ratio is within the stable combustion region.

[0145] Furthermore, the present disclosure is not limited to the embodiments and modifications described above. Various additions, modifications, substitutions, partial deletions, etc. are possible within the scope of the conceptual idea and intent of the present invention derived from the contents defined in the claims and their equivalents.

[0146] "Additional Notes" The control method for the gas turbine plant in the above embodiment can be understood, for example, as follows. (1) The method for controlling a gas turbine plant according to the first aspect is applied to the following gas turbine plant. This gas turbine plant includes a gas turbine 1 having an intake duct 3 through which air A can flow, a compressor 10 capable of compressing the air A from the intake duct 3 to generate compressed air Acom, a combustor 20 capable of burning a fuel F in the compressed air Acom to generate combustion gas CG, and a turbine 30 capable of being driven by the combustion gas CG, a first fuel control valve 44a capable of adjusting a flow rate of a first fuel Fp which is a part of the fuel F supplied to the combustor 20, and a second fuel control valve 44b capable of adjusting a flow rate of a second fuel Fm which is another part of the fuel F supplied to the combustor 20. The compressor 10 includes a compressor rotor 11 capable of rotating about a rotor axis, a compressor casing 14 which covers the compressor rotor 11, and an intake air regulator 16 capable of adjusting the flow rate of the air A flowing into the compressor casing 14. The intake air amount regulator 16 has a plurality of inlet guide vanes 17 and a driver 18 capable of changing the opening degree of the plurality of inlet guide vanes 17. The combustor 20 has a cylinder 28 in which the fuel F can be burned, a first nozzle 26a capable of injecting the first fuel Fp, a first air flow passage frame 27a through which first air Ap which is a part of the compressed air Acom flowing into the combustor 20 and the first fuel Fp from the first nozzle 26a can flow, a second nozzle 26b capable of injecting the second fuel Fm, and a second air flow passage frame 27b through which second air Am which is another part of the compressed air Acom flowing into the combustor 20 and the second fuel Fm from the second nozzle 26b can flow. This gas turbine plant control method includes a fuel flow rate estimation step S12 for estimating a fuel flow rate Gf of the fuel F actually flowing into the combustor 20, an air flow rate estimation step S13 for estimating an air flow rate Ga of the compressed air Acom actually flowing into the combustor 20, a combustion oscillation determination step S10 for determining whether or not a combustion oscillation occurrence state has occurred in which an internal pressure fluctuation in the cylinder 28 is greater than a predetermined value, and when it is determined in the combustion oscillation determination step S10 that the combustion oscillation occurrence state has occurred, a corrected flow rate ratio calculation step S11 for calculating a corrected flow rate ratio that is a flow rate ratio that can avoid the combustion oscillation occurrence state by using relationship data between an increase / decrease in combustion oscillation and an increase / decrease in a flow rate ratio of the first fuel Fp to the flow rate of the fuel F supplied to the combustor 20, and a burner fuel-air ratio calculation step S14 for calculating a first fuel-air ratio P·F / A which is a ratio of a flow rate of the second fuel Fm to a flow rate of the second air Am, and a second fuel-air ratio M·F / A which is a ratio of a flow rate of the second fuel Fm to a flow rate of the second air Am; a stable combustion determination step S15 for determining whether or not each of the first fuel-air ratio P·F / A and the second fuel-air ratio M·F / A is a fuel-air ratio within a predetermined stable combustion region in which there is no possibility of misfire or backfire; and, when it is determined in the stable combustion determination step S15 that both the first fuel-air ratio P·F / A and the second fuel-air ratio M·F / A are fuel-air ratios within the stable combustion region, an instruction step S16 (S5) for instructing the first fuel control valve 44a and the second fuel control valve 44b so that a flow rate ratio of the flow rate of the first fuel Fp to the flow rate of the fuel F supplied to the combustor 20 becomes the corrected flow rate ratio. The fuel flow rate Gf estimated in the fuel flow rate estimation step S12 is the flow rate of the fuel F flowing into the combustor 20, and is determined based on the intake air temperature Ti which is the temperature of the air A flowing into the compressor casing 14, the IGV aperture which is the aperture of the multiple inlet guide vanes 17, and the GT output PW which is the output of the gas turbine 1. The air flow rate Ga estimated in the air flow rate estimation step S13 is the flow rate of the compressed air Acom flowing into the combustor 20, and is determined based on the intake air temperature Ti, the IGV aperture, and the GT output PW. In the burner fuel-air ratio calculation step S14, the flow rate of the first fuel Fp and the flow rate of the second fuel Fm are determined using the corrected flow rate ratio and the fuel flow rate Gf estimated in the fuel flow rate estimation step S12, and the flow rate of the first air Ap and the flow rate of the second air Am are determined using a predetermined flow rate ratio of air A between the flow rate of the first air Ap flowing through the first air flow path frame 27a and the flow rate of the second air Am flowing through the second air flow path frame 27b, and the air flow rate Ga estimated in the air flow rate estimation step S13.

[0147] In this embodiment, in the combustion oscillation judgment step S10, it is judged whether or not the internal pressure fluctuation in the cylinder 28 is greater than a predetermined value and the combustion oscillation occurs. If it is judged in this combustion oscillation judgment step S10 that the combustion oscillation occurs, a corrected flow rate ratio that is a flow rate ratio that can avoid the combustion oscillation occurs is calculated in the corrected flow rate ratio calculation step S11. In the burner fuel-air ratio calculation step S14, a first fuel-air ratio P·F / A that is the ratio of the flow rate of the first fuel Fp to the flow rate of the first air Ap, and a second fuel-air ratio M·F / A that is the ratio of the flow rate of the second fuel Fm to the flow rate of the second air Am are calculated. That is, in the burner fuel-air ratio calculation step S14, the fuel-air ratio in the first burner having the first nozzle 26a and the first air passage frame 27a, and the fuel-air ratio in the second burner having the second nozzle 26b and the second air passage frame 27b are calculated. In the burner fuel-air ratio calculation step S14, the fuel flow rate Gf of the fuel F that actually flows into the combustor 20, estimated in the fuel flow rate estimation step S12, and the air flow rate Ga of the compressed air Acom that actually flows into the combustor 20, estimated in the air flow rate estimation step S13, are used to obtain the fuel-air ratio for each burner. In the stable combustion determination step S15, it is determined whether the fuel-air ratio for each burner is within a predetermined stable combustion region in which there is no possibility of misfire or backfire. Therefore, in this embodiment, it is possible to grasp with high accuracy whether the fuel F will burn stably.

[0148] When it is determined in the stable combustion determination step S15 that the fuel-air ratio for each burner is within a predetermined stable combustion region in which there is no possibility of misfire or backfire, in the instruction step S16, an instruction is given to the first fuel control valve 44a and the second fuel control valve 44b so that the flow rate ratio of the flow rate of the first fuel Fp to the flow rate of the fuel F supplied to the combustor 20 becomes a corrected flow rate ratio.

[0149] Therefore, in this embodiment, it is possible to suppress the combustion oscillation in the combustor 20 while determining with high accuracy whether or not the fuel F will burn stably, thereby enabling the fuel F to be burned stably.

[0150] (2) A method for controlling a gas turbine plant according to a second aspect includes the steps of: In the control method for a gas turbine plant in the first aspect, when it is determined in the stable combustion determination step S15 that at least one of the first fuel-air ratio P·F / A and the second fuel-air ratio M·F / A is not a fuel-air ratio within the stable combustion region, the corrected flow rate ratio calculation step S11 uses the relationship data to determine a new corrected flow rate ratio which is a flow rate ratio capable of avoiding the combustion oscillation occurrence state, the burner fuel-air ratio calculation step S14 determines a new first fuel-air ratio P·F / A and a new second fuel-air ratio M·F / A based on the new corrected flow rate ratio, and the stable combustion determination step S15 determines whether or not each of the new first fuel-air ratio P·F / A and the new second fuel-air ratio M·F / A is a fuel-air ratio within the stable combustion region.

[0151] In this embodiment, the fuel F can be burned stably.

[0152] (3) A method for controlling a gas turbine plant according to a third aspect includes the steps of: In the control method for a gas turbine plant according to the first aspect, the fuel flow rate Gf estimated in the fuel flow rate estimation step S12 is a value obtained by multiplying a basic fuel flow rate Gfb by a fuel amount time-varying ratio αf, which is a ratio of an estimated actual fuel flow rate Gfer to a past actual fuel flow rate. The basic fuel flow rate Gfb is a flow rate of the fuel F flowing into the combustor 20, which is determined based on the intake air temperature Ti, the IGV aperture, and the GT output PW at the estimation time when the fuel flow rate Gf is estimated. The estimated actual fuel flow rate Gfer is a flow rate of the fuel F flowing into the combustor 20, which is determined based at least on an actual pressure difference of the fuel F before and after the first fuel control valve 44a and an actual pressure difference of the fuel F before and after the second fuel control valve 44b at the estimation time. The past actual fuel flow rate is the flow rate of the fuel F flowing into the combustor 20, which is determined based at least on the actual pressure difference of the fuel F before and after the first fuel control valve 44a and the actual pressure difference of the fuel F before and after the second fuel control valve 44b at a time that is earlier than the estimation time and at the same GT output PW as the estimation time.

[0153] In this aspect, the fuel flow rate Gf estimated in the fuel flow rate estimation step S12 is a value that takes into account the change in the fuel amount over time, so that a first fuel-air ratio P·F / A and a second fuel-air ratio M·F / A with high reliability can be obtained.

[0154] (4) A method for controlling a gas turbine plant according to a fourth aspect includes the steps of: In the control method for a gas turbine plant according to the first aspect, the fuel flow rate estimation step S12 includes an estimation time actual fuel flow rate calculation step S121 for calculating an estimation time actual fuel flow rate Gfer, which is the flow rate of the fuel F flowing into the combustor 20, based on at least an actual pressure difference of the fuel F before and after the first fuel control valve 44a and an actual pressure difference of the fuel F before and after the second fuel control valve 44b at the estimation time when the fuel flow rate Gf is estimated, a fuel ratio calculation step S122 for calculating a fuel ratio K, which is a ratio of a basic fuel flow rate Gfb to a past actual fuel flow rate at a past time before the estimation time, and a fuel flow rate calculation step S123 for multiplying the estimation time actual fuel flow rate Gfer by the fuel ratio K to calculate the fuel flow rate Gf. The basic fuel flow rate Gfb is the flow rate of the fuel F flowing into the combustor 20, which is determined based on the intake air temperature Ti, the IGV aperture, and the GT output PW at the estimation time. The past actual fuel flow rate is the flow rate of the fuel F flowing into the combustor 20, which is determined based at least on the actual pressure difference of the fuel F before and after the first fuel control valve 44a and the actual pressure difference of the fuel F before and after the second fuel control valve 44b at the past time and when the GT output PW is the same as that at the estimated time.

[0155] Also in this embodiment, the fuel flow rate Gf estimated in the fuel flow rate estimation step S12 is a value that takes into account the change in the fuel amount over time, so that a first fuel-air ratio P·F / A and a second fuel-air ratio M·F / A with high reliability can be obtained.

[0156] (5) A method for controlling a gas turbine plant according to a fifth aspect includes the steps of: In the gas turbine plant control method according to the fourth aspect, in the fuel ratio calculation step S122, a past fuel ratio K for the GT output PW at the estimation time is calculated using a previously calculated output-fuel ratio past relationship which is a relationship between the GT output PW and the fuel ratio K at the past time.

[0157] In this embodiment, the past fuel ratio K with respect to the GT output PW at the time of estimation can be easily obtained.

[0158] (6) A method for controlling a gas turbine plant according to a sixth aspect includes the steps of: In the fifth aspect of the gas turbine plant control method, a relationship setting step is performed to determine the output-fuel ratio past relationship. In the relationship setting step, the output range of the gas turbine 1 from the minimum output to the maximum output of the gas turbine 1 is divided into a plurality of ranges, divided ranges Rpw obtained by dividing the range into a plurality of ranges are determined, and for each of the plurality of divided ranges Rpw, a representative point is determined in a coordinate system in which the GT output PW and the past fuel ratio K are variables, and the representative points for each of the plurality of divided ranges Rpw in the coordinate system are connected with a line to determine a function of the past fuel ratio K with the GT output PW as a variable, and the function is the output-fuel ratio past relationship. The representative points for each of the plurality of divided ranges Rpw are points that represent the past fuel ratio K for each of the plurality of GT outputs PW in each divided range Rpw.

[0159] (7) A seventh aspect of a method for controlling a gas turbine plant includes the steps of: In the gas turbine plant control method according to any one of the first to sixth aspects, the air flow rate Ga estimated in the air flow rate estimation step S13 is a value obtained by multiplying a basic air flow rate Gab by an air amount time-dependent change ratio αa, which is a ratio of an estimated actual air flow rate Gaer to a past actual air flow rate Gapr. The basic air flow rate Gab is the flow rate of the compressed air Acom flowing into the combustor 20, which is determined based on the intake air temperature Ti, the IGV aperture, and the GT output PW at the estimation time when the fuel flow rate Gf is estimated. The estimated actual air flow rate Gaer is the flow rate of the compressed air Acom flowing into the combustor 20, which is determined based at least on an actual pressure difference of the air A between two points in the intake duct 3 at the estimation time. The past actual air flow rate Gapr is the flow rate of the compressed air Acom flowing into the combustor 20, which is determined based at least on the actual pressure difference of the air A between the two points in the intake duct 3 at a time earlier than the estimated time and when the IGV opening is the same as that at the estimated time.

[0160] In this aspect, the air flow rate Ga estimated in the air flow rate estimation step S13 is a value that takes into account changes in the air amount over time, so that a first fuel-air ratio P·F / A and a second fuel-air ratio M·F / A with high reliability can be obtained.

[0161] (8) An eighth aspect of a method for controlling a gas turbine plant includes the steps of: In the control method for a gas turbine plant according to any one of the first to sixth aspects, the air flow rate estimation step S13 includes an estimated actual air flow rate calculation step S131 of calculating an estimated actual air flow rate Gaer, which is the flow rate of the compressed air Acom flowing into the combustor 20, based on at least an actual pressure difference of the air A between two points in the intake duct 3 at a time when the fuel flow rate Gf is estimated; and The method includes a basic air flow rate calculation step S132 for calculating a basic air flow rate Gab, which is a flow rate of air Acom, an estimation time air ratio calculation step S134 for calculating an estimation time air ratio δe, which is a ratio of the estimation time actual air flow rate Gaer to the basic air flow rate Gab, a past time air ratio calculation step S133 for calculating a past time air ratio δp, which is a ratio of the past actual air flow rate Gapr to the basic air flow rate Gab, and an air flow rate calculation step S135 for multiplying the basic air flow rate Gab by the ratio of the estimation time air ratio δe to the past time air ratio δp to calculate the air flow rate Ga. The past time actual air flow rate Gapr is the flow rate of the compressed air Acom flowing into the combustor 20, which is determined based at least on the actual pressure difference of the air A between the two points in the intake duct 3 at a time earlier than the estimation time and at the same IGV opening as the estimation time.

[0162] Also in this embodiment, the air flow rate Ga estimated in the air flow rate estimation step S13 is a value that takes into account the change in the air amount over time, so that a first fuel-air ratio P·F / A and a second fuel-air ratio M·F / A with high reliability can be obtained.

[0163] (9) A ninth aspect of a method for controlling a gas turbine plant includes the steps of: In the eighth aspect of the control method for a gas turbine plant, in the past air ratio calculation step S133, the past air ratio δp for the IGV opening at the estimation time is calculated using a predetermined opening-past air ratio relationship, which is the relationship between the IGV opening at the past time and the past air ratio δp.

[0164] In this embodiment, the past air ratio Δp for the IGV opening degree at the time of estimation can be easily obtained.

[0165] (10) A method for controlling a gas turbine plant according to a tenth aspect includes the steps of: In the gas turbine plant control method according to the ninth aspect, a relationship setting step of determining the opening-past air ratio relationship is executed. In the relationship setting step, a range in which the openings of the inlet guide vanes 17 can be changed is divided into a plurality of ranges, divided ranges Rigv obtained by dividing the range into a plurality of ranges are determined, a representative point is determined for each of the plurality of divided ranges Rigv in a coordinate system having the IGV opening and the past air ratio δp as variables, and a function of the past air ratio δp having the IGV opening as a variable is determined by connecting the representative points for each of the plurality of divided ranges Rigv in the coordinate system with lines, and the representative points for each of the plurality of divided ranges Rigv are points representative of the past air ratios δp for each of the plurality of IGV openings in each divided range Rigv, and the function is the opening-past air ratio relationship.

[0166] (11) A method for controlling a gas turbine plant according to an eleventh aspect includes the steps of: In the control method for a gas turbine plant in any one of the first to tenth aspects, the following steps are executed: a fuel flow rate command generating step S1 for generating a fuel flow rate command CSO indicating a total fuel flow rate Gf to be supplied to the combustor 20 based on a required power PWr that is a required value from outside related to the GT output PW; a combustion load command generating step S3 for generating a combustion load command CLCSO indicating a combustion load that is a parameter having a positive correlation with an inlet temperature that is the temperature of the combustion gas CG at an inlet of the turbine 30; and a load corresponding flow rate ratio calculating step S4 for calculating a load corresponding flow rate ratio that is a ratio of a flow rate of the first fuel Fp to the flow rate of the fuel F supplied to the combustor 20, in accordance with the combustion load indicated by the combustion load command CLCSO. In the instructing step S16 (S5), the first fuel control valve 44a and the second fuel control valve 44b are instructed so that the flow rate of the fuel F supplied to the combustor 20 becomes the total fuel flow rate Gf generated in the fuel flow rate command generating step S1 and becomes the load corresponding flow rate ratio, and when it is determined in the combustion oscillation determining step S10 that the combustion oscillation occurrence state has occurred and it is determined in the stable combustion determining step S15 that both the first fuel-air ratio P·F / A and the second fuel-air ratio M·F / A are fuel-air ratios within the stable combustion region, the first fuel control valve 44a and the second fuel control valve 44b are instructed so that the flow rate ratio of the flow rate of the first fuel Fp to the flow rate of the fuel F supplied to the combustor 20 becomes the corrected flow rate ratio used in the process of calculating the first fuel-air ratio P·F / A and the second fuel-air ratio M·F / A.

[0167] The control device for a gas turbine plant in the above embodiment can be understood, for example, as follows. (12) The control device for a gas turbine plant in a twelfth aspect is applied to the following gas turbine plant. This gas turbine plant includes a gas turbine 1 having an intake duct 3 through which air A can flow, a compressor 10 capable of compressing the air A from the intake duct 3 to generate compressed air Acom, a combustor 20 capable of burning a fuel F in the compressed air Acom to generate combustion gas CG, and a turbine 30 capable of being driven by the combustion gas CG, a first fuel control valve 44a capable of adjusting a flow rate of a first fuel Fp which is a part of the fuel F supplied to the combustor 20, and a second fuel control valve 44b capable of adjusting a flow rate of a second fuel Fm which is another part of the fuel F supplied to the combustor 20. The compressor 10 includes a compressor rotor 11 capable of rotating about a rotor axis, a compressor casing 14 which covers the compressor rotor 11, and an intake air regulator 16 capable of adjusting the flow rate of the air A flowing into the compressor casing 14. The intake air amount regulator 16 has a plurality of inlet guide vanes 17 and a driver 18 capable of changing the opening degree of the plurality of inlet guide vanes 17. The combustor 20 has a cylinder 28 in which the fuel F can be burned, a first nozzle 26a capable of injecting the first fuel Fp, a first air flow passage frame 27a through which first air Ap which is a part of the compressed air Acom flowing into the combustor 20 and the first fuel Fp from the first nozzle 26a can flow, a second nozzle 26b capable of injecting the second fuel Fm, and a second air flow passage frame 27b through which second air Am which is another part of the compressed air Acom flowing into the combustor 20 and the second fuel Fm from the second nozzle 26b can flow. The gas turbine plant control device 100 includes a fuel flow rate estimator 121 that estimates a fuel flow rate Gf of the fuel F that actually flows into the combustor 20, an air flow rate estimator 131 that estimates an air flow rate Ga of the compressed air Acom that actually flows into the combustor 20, a combustion oscillation determiner 140 that determines whether or not a combustion oscillation occurrence state has occurred in which an internal pressure fluctuation in the cylinder 28 is greater than a predetermined value, a relationship data memory 144 that stores relationship data between an increase / decrease in combustion oscillation and an increase / decrease in a flow rate ratio of the flow rate of the first fuel Fp to the flow rate of the fuel F supplied to the combustor 20, and a corrected flow rate ratio calculator 145 that calculates a corrected flow rate ratio that can avoid the combustion oscillation occurrence state by using the relationship data stored in the relationship data memory 144 when it is determined by the combustion oscillation determiner 140 that the combustion oscillation occurrence state has occurred. a burner fuel-air ratio calculator 142 for calculating a first fuel-air ratio P·F / A which is a ratio of a flow rate of the first fuel Fp to a flow rate of the first air Ap, and a second fuel-air ratio M·F / A which is a ratio of a flow rate of the second fuel Fm to a flow rate of the second air Am, a stable combustion determiner 143 for determining whether or not each of the first fuel-air ratio P·F / A and the second fuel-air ratio M·F / A is a fuel-air ratio within a predetermined stable combustion region in which there is no possibility of misfire or backfire, and an indicator 151 for instructing the first fuel control valve 44a and the second fuel control valve 44b, when the stable combustion determiner 143 determines that both of the first fuel-air ratio P·F / A and the second fuel-air ratio M·F / A are fuel-air ratios within the stable combustion region. The fuel flow rate Gf estimated by the fuel flow rate estimator 121 is the flow rate of the fuel F flowing into the combustor 20, and is determined based on the intake temperature Ti which is the temperature of the air A flowing into the compressor casing 14, the IGV aperture which is the aperture of the multiple inlet guide vanes 17, and the GT output PW which is the output of the gas turbine 1. The air flow rate Ga estimated by the air flow rate estimator 131 is the flow rate of the compressed air Acom flowing into the combustor 20, and is determined based on the intake temperature Ti, the IGV aperture, and the GT output PW. The burner fuel-air ratio calculator 142 determines the flow rate of the first fuel Fp and the flow rate of the second fuel Fm using the corrected flow rate ratio and the fuel flow rate Gf estimated by the fuel flow rate estimator 121, and determines the flow rate of the first air Ap and the flow rate of the second air Am using a predetermined flow rate ratio of the air A between the flow rate of the first air Ap flowing through the first air flow path frame 27a and the flow rate of the second air Am flowing through the second air flow path frame 27b, and the air flow rate Ga estimated by the air flow rate estimator 131.

[0168] In this embodiment, similarly to the control method in the first embodiment, it is possible to suppress combustion oscillation in the combustor 20 while grasping with high accuracy whether or not the fuel F is stably combusted, thereby enabling the fuel F to be stably combusted.

[0169] (13) A gas turbine plant control device according to a thirteenth aspect, In the gas turbine plant control device 100 in the twelfth aspect, when the stable combustion determiner 143 determines that at least one of the first fuel-air ratio P·F / A and the second fuel-air ratio M·F / A is not a fuel-air ratio within the stable combustion region, the corrected flow rate ratio calculator 141 uses the relationship data to calculate a new corrected flow rate ratio that is a flow rate ratio that can avoid the combustion oscillation occurrence state. The burner fuel-air ratio calculator 142 calculates a new first fuel-air ratio P·F / A and a new second fuel-air ratio M·F / A based on the new corrected flow rate ratio. The stable combustion determiner 143 determines whether or not each of the new first fuel-air ratio P·F / A and the new second fuel-air ratio M·F / A is a fuel-air ratio within the stable combustion region.

[0170] In this embodiment, like the control method in the second embodiment, the fuel F can be stably burned.

[0171] (14) A control device for a gas turbine plant according to a fourteenth aspect, In the gas turbine plant control device 100 according to the twelfth aspect, the fuel flow rate Gf estimated by the fuel flow rate estimator 121 is a value obtained by multiplying a basic fuel flow rate Gfb by a fuel amount time-varying ratio αf, which is a ratio of an estimated actual fuel flow rate Gfer to a past actual fuel flow rate. The basic fuel flow rate Gfb is a flow rate of the fuel F flowing into the combustor 20, which is determined based on the intake air temperature Ti, the IGV aperture, and the GT output PW at the time of estimation when the fuel flow rate Gf is estimated. The estimated actual fuel flow rate Gfer is a flow rate of the fuel F flowing into the combustor 20, which is determined based at least on an actual pressure difference of the fuel F before and after the first fuel control valve 44a and an actual pressure difference of the fuel F before and after the second fuel control valve 44b at the time of estimation. The past actual fuel flow rate is the flow rate of the fuel F flowing into the combustor 20, which is determined based at least on the actual pressure difference of the fuel F before and after the first fuel control valve 44a and the actual pressure difference of the fuel F before and after the second fuel control valve 44b at a time that is earlier than the estimation time and at the same GT output PW as the estimation time.

[0172] In this embodiment, similarly to the control method in the third embodiment, it is possible to determine a first fuel-air ratio P·F / A and a second fuel-air ratio M·F / A with high reliability.

[0173] (15) A fifteenth aspect of the present invention provides a gas turbine plant control device, comprising: In the gas turbine plant control device 100 in the twelfth aspect, the fuel flow rate estimator 121 includes an estimated actual fuel flow rate calculation unit 122 that calculates an estimated actual fuel flow rate Gfer, which is the flow rate of the fuel F flowing into the combustor 20, based on at least an actual pressure difference of the fuel F before and after the first fuel control valve 44a and an actual pressure difference of the fuel F before and after the second fuel control valve 44b at the estimation time when the fuel flow rate Gf is estimated, a fuel ratio calculation unit 123 that calculates a fuel ratio K that is a ratio of a basic fuel flow rate Gfb to a past actual fuel flow rate at a time that is older than the estimation time, and a fuel flow rate calculation unit 124 that multiplies the estimated actual fuel flow rate Gfer by the fuel ratio K to calculate the fuel flow rate Gf. The basic fuel flow rate Gfb is the flow rate of the fuel F flowing into the combustor 20 at the estimation time, which is determined based on the intake air temperature Ti, the IGV aperture, and the GT output PW. The past actual fuel flow rate is the flow rate of the fuel F flowing into the combustor 20, which is determined based at least on the actual pressure difference of the fuel F before and after the first fuel control valve 44a and the actual pressure difference of the fuel F before and after the second fuel control valve 44b at the past time and when the GT output PW is the same as that at the estimated time.

[0174] In this aspect, similarly to the control method in the fourth aspect, it is possible to determine a first fuel-air ratio P·F / A and a second fuel-air ratio M·F / A with high reliability.

[0175] (16) A gas turbine plant control device according to a sixteenth aspect, In the gas turbine plant control device 100 in the fifteenth aspect, the fuel ratio calculation unit 123 pre-stores an output-fuel ratio past relationship which is the relationship between the GT output PW at the past time and the fuel ratio K at the past time, and calculates the past fuel ratio K for the GT output PW at the estimation time at the past time using the output-fuel ratio past relationship.

[0176] In this embodiment, similarly to the control method in the fifth embodiment, the past fuel ratio K with respect to the GT output PW at the time of estimation can be easily obtained.

[0177] (17) A seventeenth aspect of the control device for a gas turbine plant includes: The gas turbine plant control device 100 in the sixteenth aspect includes a relationship setter 128 that determines the output-fuel ratio past relationship. The relationship setter 128 divides the range of the output of the gas turbine 1 from the minimum output to the maximum output of the gas turbine 1 into a plurality of ranges, determines divided ranges Rpw obtained by dividing the range into a plurality of ranges, determines a representative point in a coordinate system in which the GT output PW and the past fuel ratio K are variables for each of the plurality of divided ranges Rpw, and connects the representative points for each of the plurality of divided ranges Rpw in the coordinate system with a line to determine a function of the past fuel ratio K with the GT output PW as a variable, and sets the function as the output-fuel ratio past relationship. The representative points for each of the plurality of divided ranges Rpw are points that represent the past fuel ratio K for each of the plurality of GT outputs PW in each divided range Rpw.

[0178] (18) In an eighteenth aspect, there is provided a gas turbine plant control device, In the gas turbine plant control device 100 according to any one of the twelfth to seventeenth aspects, the air flow rate Ga estimated by the air flow rate estimator 131 is a value obtained by multiplying a basic air flow rate Gab by an air amount time-varying ratio αa, which is a ratio of an estimated actual air flow rate Gaer to a past actual air flow rate Gapr. The basic air flow rate Gab is the flow rate of the compressed air Acom flowing into the combustor 20, which is calculated based on the intake air temperature Ti, the IGV opening degree, and the GT output PW at the estimation time when the fuel flow rate Gf is estimated. The estimated actual air flow rate Gaer is the flow rate of the compressed air Acom flowing into the combustor 20, which is calculated based on at least an actual pressure difference of the air A between two points in the intake duct 3 at the estimation time. The past actual air flow rate Gapr is the flow rate of the compressed air Acom flowing into the combustor 20, which is calculated based at least on the actual pressure difference of the air A between the two points in the intake duct 3 at a time earlier than the estimated time and when the IGV opening is the same as that at the estimated time.

[0179] In this aspect, similarly to the control method in the seventh aspect, it is possible to determine the first fuel-air ratio P·F / A and the second fuel-air ratio M·F / A with high reliability.

[0180] (19) A nineteenth aspect of the control device for a gas turbine plant includes: In the control device 100 for a gas turbine plant according to any one of the twelfth to seventeenth aspects, the air flow rate estimator 131 includes a basic air flow rate calculation unit 132 that calculates a basic air flow rate Gab, which is the flow rate of the compressed air Acom flowing into the combustor 20, based on the intake temperature Ti, the IGV aperture, and the GT output PW at the time of estimation when the fuel flow rate Gf is estimated, and a basic air flow rate calculation unit 132 that calculates a basic air flow rate Gab, which is the flow rate of the compressed air Acom flowing into the combustor 20, based on at least an actual pressure difference of the air A between two points in the intake duct 3 at the time of the estimation. The control system includes an estimated actual air flow rate calculation unit 133 for calculating an estimated actual air flow rate Gaer, which is a flow rate of the compressed air Acom, an estimated air ratio calculation unit 134 for calculating an estimated air ratio δe, which is a ratio of the estimated actual air flow rate Gaer to the basic air flow rate Gab, a past air ratio calculation unit 135 for calculating a past air ratio δp, which is a ratio of the past actual air flow rate Gapr to the basic air flow rate Gab, and an air flow rate calculation unit 136 for multiplying the basic air flow rate Gab by the ratio of the estimated air ratio δe to the past air ratio δp to calculate the air flow rate Ga. The past actual air flow rate Gapr is the flow rate of the compressed air Acom flowing into the combustor 20, which is determined based at least on the actual pressure difference of the air A between the two points in the intake duct 3 at a time earlier than the estimation time and at the same IGV opening as that at the estimation time.

[0181] In this aspect, similarly to the control method in the eighth aspect, it is possible to determine a first fuel-air ratio P·F / A and a second fuel-air ratio M·F / A with high reliability.

[0182] (20) In a twentieth aspect, a control device for a gas turbine plant includes: In the gas turbine plant control device 100 in the nineteenth aspect, the past air ratio calculation unit 135 pre-stores an opening-past air ratio relationship, which is the relationship between the IGV opening at the past and the past air ratio δp, and calculates the past air ratio δp for the IGV opening at the estimation time using the opening-past air ratio relationship.

[0183] In this aspect, similarly to the control method in the ninth aspect, the past air ratio Δp with respect to the IGV opening degree at the time of estimation can be easily obtained in the past.

[0184] (21) A gas turbine plant control device according to a twenty-first aspect, The gas turbine plant control device 100 in the twentieth aspect includes a relationship setter 138 that determines the opening-past air ratio relationship. The relationship setter 138 divides a range in which the openings of the plurality of inlet guide vanes 17 can be changed into a plurality of ranges, determines divided ranges Rigv obtained by dividing the range into a plurality of ranges, determines a representative point for each of the plurality of divided ranges Rigv in a coordinate system having the IGV opening and the past air ratio δp as variables, respectively, and determines a function of the past air ratio δp having the IGV opening as a variable by connecting the representative points for each of the plurality of divided ranges Rigv in the coordinate system with a line, and the representative points for each of the plurality of divided ranges Rigv are points that represent the past air ratios δp for each of the plurality of IGV openings in each divided range Rigv, and the function is the opening-past air ratio relationship.

[0185] (22) A gas turbine plant control device according to a twenty-second aspect, The control device 100 for a gas turbine plant in any one of the twelfth to twenty-first aspects includes a fuel flow rate command generator 110 that generates a fuel flow rate command CSO indicating a total fuel flow rate Gf to be supplied to the combustor 20, based on a required output PWr that is a required value from outside related to the GT output PW, a combustion load command generator 112 that generates a combustion load command CLCSO that indicates a combustion load that is a parameter having a positive correlation with an inlet temperature that is the temperature of the combustion gas CG at an inlet of the turbine 30, and a load corresponding flow rate ratio calculator 113 that calculates a load corresponding flow rate ratio that is a ratio of a flow rate of the first fuel Fp to a flow rate of the fuel F supplied to the combustor 20, in accordance with the combustion load indicated by the combustion load command CLCSO. The indicator 151 instructs the first fuel control valve 44a and the second fuel control valve 44b so that the flow rate of the fuel F supplied to the combustor 20 becomes the total fuel flow rate Gf indicated by the fuel flow rate command CSO and becomes the load corresponding flow rate ratio, and instructs the first fuel control valve 44a and the second fuel control valve 44b so that the flow rate ratio of the flow rate of the first fuel Fp to the flow rate of the fuel F supplied to the combustor 20 becomes the corrected flow rate ratio used in the process of calculating the first fuel-air ratio P·F / A and the second fuel-air ratio M·F / A when the combustion oscillation determiner 140 determines that the combustion oscillation occurrence state has occurred and the stable combustion determiner 143 determines that both the first fuel-air ratio P·F / A and the second fuel-air ratio M·F / A are fuel-air ratios within the stable combustion region.

[0186] The control program for the gas turbine plant in the above embodiment can be understood, for example, as follows. (23) The control program for a gas turbine plant in the twenty-third aspect is applied to the following gas turbine plant. This gas turbine plant includes a gas turbine 1 having an intake duct 3 through which air A can flow, a compressor 10 capable of compressing the air A from the intake duct 3 to generate compressed air Acom, a combustor 20 capable of burning a fuel F in the compressed air Acom to generate combustion gas CG, and a turbine 30 capable of being driven by the combustion gas CG, a first fuel control valve 44a capable of adjusting a flow rate of a first fuel Fp which is a part of the fuel F supplied to the combustor 20, and a second fuel control valve 44b capable of adjusting a flow rate of a second fuel Fm which is another part of the fuel F supplied to the combustor 20. The compressor 10 includes a compressor rotor 11 capable of rotating about a rotor axis, a compressor casing 14 which covers the compressor rotor 11, and an intake air regulator 16 capable of adjusting the flow rate of the air A flowing into the compressor casing 14. The intake air amount regulator 16 has a plurality of inlet guide vanes 17 and a driver 18 capable of changing the opening degree of the plurality of inlet guide vanes 17. The combustor 20 has a cylinder 28 in which the fuel F can be burned, a first nozzle 26a capable of injecting the first fuel Fp, a first air flow passage frame 27a through which first air Ap which is a part of the compressed air Acom flowing into the combustor 20 and the first fuel Fp from the first nozzle 26a can flow, a second nozzle 26b capable of injecting the second fuel Fm, and a second air flow passage frame 27b through which second air Am which is another part of the compressed air Acom flowing into the combustor 20 and the second fuel Fm from the second nozzle 26b can flow. The control program for the gas turbine plant includes a fuel flow rate estimation step S12 for estimating a fuel flow rate Gf of the fuel F actually flowing into the combustor 20, an air flow rate estimation step S13 for estimating an air flow rate Ga of the compressed air Acom actually flowing into the combustor 20, a combustion oscillation determination step S10 for determining whether or not a combustion oscillation occurrence state has occurred in which an internal pressure fluctuation in the cylinder 28 is greater than a predetermined value, and, if it is determined in the combustion oscillation determination step S10 that the combustion oscillation occurrence state has occurred, a corrected flow rate ratio calculation step S11 for calculating a corrected flow rate ratio that is a flow rate ratio that can avoid the combustion oscillation occurrence state by using relationship data between an increase / decrease in combustion oscillation and an increase / decrease in a flow rate ratio of the first fuel Fp to the flow rate of the fuel F supplied to the combustor 20, and the first fuel-air ratio P·F / A being a ratio of the amount of the second fuel Fm to the amount of the second air Am, and a second fuel-air ratio M·F / A being a ratio of the amount of the second fuel Fm to the amount of the second air Am; a stable combustion determination step S15 determining whether or not each of the first fuel-air ratio P·F / A and the second fuel-air ratio M·F / A is a fuel-air ratio within a predetermined stable combustion region in which there is no possibility of misfire or backfire; and an instruction step S16 (S5) of instructing the first fuel control valve 44a and the second fuel control valve 44b so that a flow rate ratio of the flow rate of the first fuel Fp to the flow rate of the fuel F supplied to the combustor 20 becomes the corrected flow rate ratio when it is determined in the stable combustion determination step S15 that both the first fuel-air ratio P·F / A and the second fuel-air ratio M·F / A are within the stable combustion region. The fuel flow rate Gf estimated in the fuel flow rate estimation step S12 is the flow rate of the fuel F flowing into the combustor 20, and is determined based on the intake air temperature Ti which is the temperature of the air A flowing into the compressor casing 14, the IGV aperture which is the aperture of the multiple inlet guide vanes 17, and the GT output PW which is the output of the gas turbine 1. The air flow rate Ga estimated in the air flow rate estimation step S13 is the flow rate of the compressed air Acom flowing into the combustor 20, and is determined based on the intake air temperature Ti, the IGV aperture, and the GT output PW. In the burner fuel-air ratio calculation step S14, the flow rate of the first fuel Fp and the flow rate of the second fuel Fm are determined using the corrected flow rate ratio and the fuel flow rate Gf estimated in the fuel flow rate estimation step S12, and the flow rate of the first air Ap and the flow rate of the second air Am are determined using a predetermined flow rate ratio of air A between the flow rate of the first air Ap flowing through the first air flow path frame 27a and the flow rate of the second air Am flowing through the second air flow path frame 27b, and the air flow rate Ga estimated in the air flow rate estimation step S13.

[0187] By having a computer execute the control program of this embodiment, as in the control method of the first embodiment, it is possible to suppress combustion oscillations in the combustor 20, while determining with high accuracy whether or not the fuel F is burning stably, and to burn the fuel F stably.

[0188] (24) A twenty-fourth aspect of a control program for a gas turbine plant includes: In the gas turbine plant control program in the twenty-third aspect, when it is determined in the stable combustion determination step S15 that at least one of the first fuel-air ratio P·F / A and the second fuel-air ratio M·F / A is not within the stable combustion region, the corrected flow rate ratio calculation step S11 uses the relationship data to calculate a new corrected flow rate ratio that is a flow rate ratio that can avoid the combustion oscillation occurrence state. The burner fuel-air ratio calculation step S14 calculates a new first fuel-air ratio P·F / A and a new second fuel-air ratio M·F / A based on the new corrected flow rate ratio. The stable combustion determination step S15 determines whether or not each of the new first fuel-air ratio P·F / A and the new second fuel-air ratio M·F / A is within the stable combustion region.

[0189] By causing a computer to execute the control program of this embodiment, the fuel F can be stably combusted, as in the control method of the second embodiment.

[0190] (25) A control program for a gas turbine plant according to a twenty-fifth aspect, In the control program for a gas turbine plant according to the twenty-third aspect, the fuel flow rate Gf estimated in the fuel flow rate estimation step S12 is a value obtained by multiplying a basic fuel flow rate Gfb by a fuel amount time-varying ratio αf, which is a ratio of an estimated actual fuel flow rate Gfer to a past actual fuel flow rate. The basic fuel flow rate Gfb is a flow rate of the fuel F flowing into the combustor 20, which is determined based on the intake air temperature Ti, the IGV aperture, and the GT output PW at the estimation time when the fuel flow rate Gf is estimated. The estimated actual fuel flow rate Gfer is a flow rate of the fuel F flowing into the combustor 20, which is determined based at least on an actual pressure difference of the fuel F before and after the first fuel control valve 44a and an actual pressure difference of the fuel F before and after the second fuel control valve 44b at the estimation time. The past actual fuel flow rate is the flow rate of the fuel F flowing into the combustor 20, which is determined based at least on the actual pressure difference of the fuel F before and after the first fuel control valve 44a and the actual pressure difference of the fuel F before and after the second fuel control valve 44b at a time that is earlier than the estimation time and at the same GT output PW as the estimation time.

[0191] By causing a computer to execute the control program of this aspect, it is possible to determine a first fuel-air ratio P·F / A and a second fuel-air ratio M·F / A with high reliability, as in the control method of the third aspect.

[0192] (26) A twenty-sixth aspect of a control program for a gas turbine plant includes: In the control program for the gas turbine plant in the twenty-third aspect, the fuel flow rate estimation step S12 includes an estimation time actual fuel flow rate calculation step S121 for calculating an estimation time actual fuel flow rate Gfer, which is the flow rate of the fuel F flowing into the combustor 20, based at least on an actual pressure difference of the fuel F before and after the first fuel control valve 44a and an actual pressure difference of the fuel F before and after the second fuel control valve 44b at the estimation time when the fuel flow rate Gf is estimated, a fuel ratio calculation step S122 for calculating a fuel ratio K, which is a ratio of a basic fuel flow rate Gfb to a past actual fuel flow rate at a time before the estimation time, and a fuel flow rate calculation step S123 for multiplying the estimation time actual fuel flow rate Gfer by the fuel ratio K to calculate the fuel flow rate Gf. The basic fuel flow rate Gfb is the flow rate of the fuel F flowing into the combustor 20, which is determined based on the intake air temperature Ti, the IGV aperture, and the GT output PW at the estimation time. The past actual fuel flow rate is the flow rate of the fuel F flowing into the combustor 20, which is determined based at least on the actual pressure difference of the fuel F before and after the first fuel control valve 44a and the actual pressure difference of the fuel F before and after the second fuel control valve 44b at the past time and when the GT output PW is the same as that at the estimated time.

[0193] By causing a computer to execute the control program of this aspect, it is possible to determine a first fuel-air ratio P·F / A and a second fuel-air ratio M·F / A with high reliability, as in the control method of the fourth aspect.

[0194] (27) A twenty-seventh aspect of a control program for a gas turbine plant includes: In the control program for a gas turbine plant in the twenty-sixth aspect, in the fuel ratio calculation step S122, the past fuel ratio K for the GT output PW at the estimation time is calculated using an output-past fuel ratio relationship which is a relationship between the GT output PW and the fuel ratio K at the past time that has been calculated in advance.

[0195] By having a computer execute the control program of this aspect, it is possible to easily obtain the past fuel ratio K with respect to the GT output PW at the time of estimation, in the same way as in the control method of the fifth aspect.

[0196] (28) A twenty-eighth aspect of a control program for a gas turbine plant includes: In the gas turbine plant control program in the twenty-seventh aspect, the computer is caused to execute a relationship setting step of determining the output-fuel ratio past relationship. In the relationship setting step, the range of the output of the gas turbine 1 from the minimum output to the maximum output of the gas turbine 1 is divided into a plurality of ranges, a divided range Rpw obtained by dividing the range into a plurality of ranges is determined, a representative point is determined in a coordinate system in which the GT output PW and the past fuel ratio K are variables for each of the plurality of divided ranges Rpw, and a function of the past fuel ratio K with the GT output PW as a variable is determined by connecting the representative points for each of the plurality of divided ranges Rpw in the coordinate system with a line, and the function is set as the output-fuel ratio past relationship. The representative points for each of the plurality of divided ranges Rpw are points that represent the past fuel ratio K for each of the plurality of GT outputs PW in each divided range Rpw.

[0197] (29) A twenty-ninth aspect of a control program for a gas turbine plant includes: In the control program for a gas turbine plant according to any one of the twenty-third to twenty-eighth aspects, the air flow rate Ga estimated in the air flow rate estimation step S13 is a value obtained by multiplying a basic air flow rate Gab by an air amount time-dependent change ratio αa, which is a ratio of an estimated actual air flow rate Gaer to a past actual air flow rate Gapr. The basic air flow rate Gab is a flow rate of the compressed air Acom flowing into the combustor 20, which is determined based on the intake air temperature Ti, the IGV aperture, and the GT output PW at the estimation time when the fuel flow rate Gf is estimated. The estimated actual air flow rate Gaer is a flow rate of the compressed air Acom flowing into the combustor 20, which is determined based at least on an actual pressure difference of the air A between two points in the intake duct 3 at the estimation time. The past actual air flow rate Gapr is the flow rate of the compressed air Acom flowing into the combustor 20, which is determined based at least on the actual pressure difference of the air A between the two points in the intake duct 3 at a time earlier than the estimated time and when the IGV opening is the same as that at the estimated time.

[0198] By causing a computer to execute the control program of this aspect, it is possible to determine a first fuel-air ratio P·F / A and a second fuel-air ratio M·F / A with high reliability, as in the control method of the seventh aspect.

[0199] (30) A control program for a gas turbine plant according to a thirtieth aspect, In the control program for a gas turbine plant according to any one of the twenty-third to twenty-eighth aspects, the air flow rate estimation step S13 includes an estimated actual air flow rate calculation step S131 for calculating an estimated actual air flow rate Gaer, which is the flow rate of the compressed air Acom flowing into the combustor 20, based on at least an actual pressure difference of the air A between two points in the intake duct 3 at an estimation time when the fuel flow rate Gf is estimated; and a pre-estimated actual air flow rate calculation step S132 for calculating an estimated actual air flow rate Gaer, which is the flow rate of the compressed air Acom flowing into the combustor 20, based on the intake air temperature Ti, the IGV aperture, and the GT output PW at the estimation time. The method includes a basic air flow rate calculation step S132 for calculating a basic air flow rate Gab, which is the flow rate of the compressed air Acom, an estimation time air ratio calculation step S134 for calculating an estimation time air ratio δe, which is a ratio of the estimation time actual air flow rate Gaer to the basic air flow rate Gab, a past time air ratio calculation step S133 for calculating a past time air ratio δp, which is a ratio of the past time actual air flow rate Gapr to the basic air flow rate Gab, and an air flow rate calculation step S135 for multiplying the basic air flow rate Gab by the ratio of the estimation time air ratio δe to the past time air ratio δp to calculate the air flow rate Ga. The past time actual air flow rate Gapr is the flow rate of the compressed air Acom flowing into the combustor 20, which is determined based at least on the actual pressure difference of the air A between the two points in the intake duct 3 at a time earlier than the estimation time and at the same IGV opening as that at the estimation time.

[0200] By causing a computer to execute the control program of this aspect, it is possible to determine a first fuel-air ratio P·F / A and a second fuel-air ratio M·F / A with high reliability, as in the control method of the eighth aspect.

[0201] (31) A control program for a gas turbine plant in a thirty-first aspect, In the control program for a gas turbine plant in the 30th aspect, in the past air ratio calculation step S133, the past air ratio δp for the IGV opening at the estimation time is calculated using a predetermined opening-past air ratio relationship, which is the relationship between the IGV opening at the past time and the past air ratio δp.

[0202] By having a computer execute the control program of this aspect, it is possible to easily obtain the past air ratio Δp with respect to the IGV opening degree at the time of estimation at the past time, as in the control method of the ninth aspect.

[0203] (32) A control program for a gas turbine plant in a thirty-second aspect, In the gas turbine plant control program according to the thirty-first aspect, the computer is caused to execute a relationship setting step of determining the opening-past air ratio relationship. In the relationship setting step, a range in which openings of the inlet guide vanes 17 can be changed is divided into a plurality of ranges, divided ranges Rigv obtained by dividing the range into a plurality of ranges are determined, a representative point is set in a coordinate system in which the IGV opening and the past air ratio δp are variables for each of the plurality of divided ranges Rigv, and a function of the past air ratio δp in which the IGV opening is a variable is determined by connecting the representative points for each of the plurality of divided ranges Rigv in the coordinate system with lines, and the representative points for each of the plurality of divided ranges Rigv are points representative of the past air ratios δp for each of the plurality of IGV openings in each divided range Rigv, and the function is the opening-past air ratio relationship.

[0204] (33) A control program for a gas turbine plant in a thirty-third aspect, In a control program for a gas turbine plant in any one of the twenty-third to thirty-second aspects, the computer is caused to execute a fuel flow rate command generating step S1 of generating a fuel flow rate command CSO indicating a total fuel flow rate Gf to be supplied to the combustor 20, based on a required power PWr that is a required value from outside related to the GT output PW, a combustion load command generating step S3 of generating a combustion load command CLCSO indicating a combustion load that is a parameter having a positive correlation with an inlet temperature that is the temperature of the combustion gas CG at an inlet of the turbine 30, and a load corresponding flow rate ratio calculating step S4 of calculating a load corresponding flow rate ratio that is a ratio of a flow rate of the first fuel Fp to the flow rate of the fuel F supplied to the combustor 20, in accordance with the combustion load indicated by the combustion load command CLCSO. In the instructing step S16 (S5), the first fuel control valve 44a and the second fuel control valve 44b are instructed so that the flow rate of the fuel F supplied to the combustor 20 becomes the total fuel flow rate Gf generated in the fuel flow rate command generating step S1 and becomes the load corresponding flow rate ratio, and when it is determined in the combustion oscillation determining step S10 that the combustion oscillation occurrence state has occurred and it is determined in the stable combustion determining step S15 that both the first fuel-air ratio P·F / A and the second fuel-air ratio M·F / A are fuel-air ratios within the stable combustion region, the first fuel control valve 44a and the second fuel control valve 44b are instructed so that the flow rate ratio of the flow rate of the first fuel Fp to the flow rate of the fuel F supplied to the combustor 20 becomes the corrected flow rate ratio used in the process of calculating the first fuel-air ratio P·F / A and the second fuel-air ratio M·F / A. [Explanation of symbols]

[0205] 1: Gas turbine 2: Gas turbine rotor 3: Intake duct 4: Intermediate casing 10: Compressor 11: Compressor rotor 12: Compressor rotor shaft 13: Compressor blade row 14: Compressor casing 15: Compressor stator blade row 16: Intake volume regulator 17: Inlet guide vane (IGV) 18: Drive unit 20: Combustor 21: Outer cylinder 22: Base plate 23: Inner cylinder 25a: Pilot burner (first burner) 25b: Main burner (second burner) 26a: Pilot nozzle (first nozzle) 26b: Main nozzle (second nozzle) 26c: Top hat nozzle (third nozzle) 27a: Pilot air passage frame (first air passage frame) 27b: Main air passage frame (second air passage frame) 28: Combustion tube (or tail tube) 30: Turbine 31: Turbine rotor 32: Turbine rotor shaft 33: Turbine blade row 34: Turbine casing 35: Turbine stator blade row 40:Fuel supply system 41: Fuel line 43a: Pilot fuel line (first fuel line) 43b: Main fuel line (secondary fuel line) 43c: Top hat fuel line (third fuel line) 44a: Pilot fuel control valve (first fuel control valve) 44b: Main fuel control valve (secondary fuel control valve) 44c: Top hat fuel control valve (third fuel control valve) 50: Output meter 51: Intake pressure differential gauge 52: Intake pressure gauge 53: Intake temperature gauge 54a: Pilot fuel pressure differential gauge 54b: Main fuel pressure differential gauge 55: Fuel pressure gauge 56:Fuel temperature gauge 57: Internal pressure fluctuation meter 100: Control device 101: Computer main unit 102:CPU 103: Main memory 104: Auxiliary storage device 104p: Control program 104pa: Flow rate adjustment program 105: Input / Output Interface 106: Storage / reproduction device 107: Equipment interface 108: Communication interface 109k: Input device 109d:Display device 110: Fuel flow command generator 111: IGV command generator 112: Combustion load command generator 113: Load-compatible flow rate ratio calculator 120:Flow ratio adjuster 121: Fuel flow estimator 122: Estimated actual fuel flow rate calculation section 123:Fuel ratio calculation section 124:Fuel flow rate calculation section 128: F(PW) setting device (related setting device) 131: Air flow estimator 132: Basic air flow rate calculation unit 133: Estimation actual air flow rate calculation unit 134: Estimation air ratio calculation section 135: Past air ratio calculation unit 136: Air flow rate calculation unit 138: F (IGV) setting device (relationship setting device) 140: Combustion vibration judgement device 141: Corrected flow rate ratio calculator 142: Burner fuel-air ratio calculator 143: Stable combustion judgement device 144: Relationship data storage device 150: Indicator 151: Fuel valve indicator 152:IGV indicator A: Air Acom: Compressed air Ap: Pilot air (first air) Am: Main air (secondary air) CG: Combustion gas F:Fuel Fp: Pilot fuel (first fuel) Fm: Main fuel (secondary fuel) PLr: Pilot ratio (corrected flow ratio, corrected pilot ratio) P·F / A: Pilot fuel-air ratio (first fuel-air ratio) M·F / A: Main fuel-air ratio (secondary fuel-air ratio) Ga: Air flow rate Gf:Fuel flow rate PW:GT output PWr: Required power ΔPi: Intake pressure difference Pi: Intake pressure Ti: Intake temperature ΔPp: Pilot fuel pressure difference ΔPm: Main fuel pressure difference Pf: Fuel pressure Tf:Fuel temperature Gab: Basic air flow rate Gfb: Basic fuel flow rate αa, αf: Ratio of change over time Gapr: Actual air flow rate at past times Gfpr:Past actual fuel flow rate Gaer: Estimated actual air flow rate Gfer: Estimated actual fuel flow rate δp: Past air ratio δe: Estimated air ratio K: fuel ratio Ar: rotor axis Ac: Combustor axis Da: Rotor axial direction Dau: Axis upstream side Dad: Downstream of axis Dc: Combustor axial direction Dcb: proximal side Dct: Tip side

Claims

1. a gas turbine including: an intake duct through which air can flow; a compressor capable of compressing the air from the intake duct to generate compressed air; a combustor capable of burning fuel in the compressed air to generate combustion gas; and a turbine capable of being driven by the combustion gas; a first fuel control valve capable of adjusting a flow rate of a first fuel which is a part of the fuel supplied to the combustor; a second fuel control valve capable of adjusting a flow rate of a second fuel which is another part of the fuel supplied to the combustor; and Equipped with The compressor includes a compressor rotor rotatable about a rotor axis, a compressor casing that covers the compressor rotor, and an intake air amount adjuster that adjusts a flow rate of air flowing into the compressor casing, the intake air amount regulator has a plurality of inlet guide vanes and a driver capable of changing an opening degree of the plurality of inlet guide vanes, The combustor includes a cylinder in which the fuel can be combusted, a first nozzle capable of injecting the first fuel, a first air flow path frame through which first air, which is a part of the compressed air flowing into the combustor, and the first fuel from the first nozzle can flow, a second nozzle capable of injecting the second fuel, and a second air flow path frame through which second air, which is another part of the compressed air flowing into the combustor, and the second fuel from the second nozzle can flow.

1. A method for controlling a gas turbine plant, comprising: a fuel flow rate estimating step of estimating a fuel flow rate of fuel actually flowing into the combustor; an air flow rate estimating step of estimating an air flow rate of the compressed air that actually flows into the combustor; a combustion oscillation determination step of determining whether or not a combustion oscillation occurring state occurs in which the internal pressure fluctuation in the cylinder is greater than a predetermined value; a corrected flow rate ratio calculation step of calculating a corrected flow rate ratio which is a flow rate ratio capable of avoiding the combustion oscillation occurrence state, using relationship data between an amount of increase or decrease in the combustion oscillation and an amount of increase or decrease in a flow rate ratio of the flow rate of the first fuel with respect to a flow rate of the fuel supplied to the combustor, when it is determined in the combustion oscillation determination step that the combustion oscillation occurrence state has occurred; a burner fuel-air ratio calculation step of calculating a first fuel-air ratio which is a ratio of a flow rate of the first fuel to a flow rate of the first air, and a second fuel-air ratio which is a ratio of a flow rate of the second fuel to a flow rate of the second air; a stable combustion determination step of determining whether or not each of the first fuel-air ratio and the second fuel-air ratio is within a predetermined stable combustion region in which there is no possibility of misfire or backfire; an instruction step of instructing the first fuel control valve and the second fuel control valve so that a flow rate ratio of the first fuel to a flow rate of fuel supplied to the combustor becomes the corrected flow rate ratio when it is determined in the stable combustion determination step that both the first fuel-air ratio and the second fuel-air ratio are within the stable combustion region; Run the fuel flow rate estimated in the fuel flow rate estimating step is a flow rate of fuel flowing into the combustor, which is determined based on an intake air temperature which is a temperature of air flowing into the compressor casing, an IGV aperture which is an aperture of the plurality of inlet guide vanes, and a GT output which is an output of the gas turbine; the air flow rate estimated in the air flow rate estimation step is a flow rate of the compressed air flowing into the combustor, the flow rate being determined based on the intake air temperature, the IGV aperture, and the GT output; In the burner fuel-air ratio calculation step, determining a flow rate of the first fuel and a flow rate of the second fuel by using the corrected flow rate ratio and the fuel flow rate estimated in the fuel flow rate estimation step; determining a flow rate of the first air and a flow rate of the second air by using a predetermined air flow rate ratio between a flow rate of the first air flowing through the first air flow path frame and a flow rate of the second air flowing through the second air flow path frame, and the air flow rate estimated in the air flow rate estimation step; A method for controlling a gas turbine plant.

2. 2. The gas turbine plant control method according to claim 1, When it is determined in the stable combustion determination step that at least one of the first fuel-air ratio and the second fuel-air ratio is not within the stable combustion region, a new corrected flow rate ratio that is a flow rate ratio that can avoid the combustion oscillation occurrence state is calculated using the relationship data in the corrected flow rate ratio calculation step S11, In the burner fuel-air ratio calculation step, a new first fuel-air ratio and a new second fuel-air ratio are calculated based on the new corrected flow ratio, In the stable combustion determination step, it is determined whether or not each of the new first fuel-air ratio and the new second fuel-air ratio is a fuel-air ratio within the stable combustion region. A method for controlling a gas turbine plant.

3. 2. The gas turbine plant control method according to claim 1, the fuel flow rate estimated in the fuel flow rate estimation step is a value obtained by multiplying a basic fuel flow rate by a fuel amount time change ratio which is a ratio of an estimated actual fuel flow rate to a past actual fuel flow rate, the basic fuel flow rate is a flow rate of fuel flowing into the combustor, the flow rate being determined based on the intake air temperature, the IGV opening degree, and the GT output at a time when the fuel flow rate is estimated, the estimated actual fuel flow rate is a flow rate of fuel flowing into the combustor, which is determined based at least on an actual pressure difference of fuel before and after the first fuel control valve and an actual pressure difference of fuel before and after the second fuel control valve at the time of the estimation, the past actual fuel flow rate is a flow rate of fuel flowing into the combustor, which is determined based at least on an actual pressure difference of fuel before and after the first fuel control valve and an actual pressure difference of fuel before and after the second fuel control valve at a time that is earlier than the estimation time and at the same GT output as the estimation time, A method for controlling a gas turbine plant.

4. 2. The gas turbine plant control method according to claim 1, The fuel flow rate estimating step includes: an estimated actual fuel flow rate calculation step of determining an estimated actual fuel flow rate, which is a flow rate of fuel flowing into the combustor, based at least on an actual pressure difference of fuel before and after the first fuel control valve and an actual pressure difference of fuel before and after the second fuel control valve at an estimation time when the fuel flow rate is estimated; a fuel ratio calculation step of calculating a fuel ratio which is a ratio of a basic fuel flow rate to a past actual fuel flow rate at a time earlier than the estimated time; a fuel flow rate calculation step of multiplying the estimated actual fuel flow rate by the fuel ratio to obtain the fuel flow rate; Including, the basic fuel flow rate is a flow rate of fuel flowing into the combustor, which is determined based on the intake temperature, the IGV opening degree, and the GT output at the time of the estimation, the past actual fuel flow rate is a flow rate of fuel flowing into the combustor, which is determined based at least on an actual pressure difference of fuel before and after the first fuel control valve and an actual pressure difference of fuel before and after the second fuel control valve at the past time and when the GT output is the same as that at the estimation time; A method for controlling a gas turbine plant.

5. 5. The gas turbine plant control method according to claim 4, In the fuel ratio calculation step, a fuel ratio at the past time relative to the GT output at the time of estimation is calculated using a previously calculated output-fuel ratio past relationship which is a relationship between the GT output and the fuel ratio at the past time. A method for controlling a gas turbine plant.

6. 6. The gas turbine plant control method according to claim 5, A relationship setting step is carried out to determine the output-fuel ratio relationship; In the relationship setting step, Dividing a range of output of the gas turbine between a minimum output and a maximum output of the gas turbine into a plurality of ranges, and determining divided ranges obtained by dividing the range into a plurality of ranges; A representative point is determined in a coordinate system having the GT output and the past fuel ratio as variables for each of the plurality of divided ranges; a function of the past fuel ratio with the GT output as a variable by connecting the representative points for each of the plurality of divided ranges in the coordinate system with lines; The function is the power-fuel ratio relationship, The representative points for each of the plurality of divided ranges are points that represent the past fuel ratios for each of the plurality of GT outputs within each of the divided ranges. A method for controlling a gas turbine plant.

7. 2. The gas turbine plant control method according to claim 1, The air flow rate estimated in the air flow rate estimation step is a value obtained by multiplying a basic air flow rate by an air flow rate temporal change ratio, which is a ratio of an estimated actual air flow rate to a past actual air flow rate, the basic air flow rate is a flow rate of the compressed air flowing into the combustor, the flow rate being determined based on the intake air temperature, the IGV aperture, and the GT output at a time when the fuel flow rate is estimated, the estimated actual air flow rate is a flow rate of the compressed air flowing into the combustor, the flow rate being determined based at least on an actual pressure difference of air between two points in the intake duct at the time of the estimation; the past actual air flow rate is a flow rate of the compressed air flowing into the combustor, the flow rate being determined based at least on an actual air pressure difference between the two points in the intake duct at a time that is earlier than the estimation time and at the same IGV opening degree as the estimation time; A method for controlling a gas turbine plant.

8. 2. The gas turbine plant control method according to claim 1, The air flow rate estimation step includes: an estimated actual air flow rate calculation step of calculating an estimated actual air flow rate, which is the flow rate of the compressed air flowing into the combustor, based at least on an actual air pressure difference between two points in the intake duct at a time when the fuel flow rate is estimated; a basic air flow rate calculation step of calculating a basic air flow rate, which is a flow rate of the compressed air flowing into the combustor, based on the intake air temperature, the IGV opening degree, and the GT output at the time of the estimation; an air ratio calculation step of calculating an air ratio at an estimation time, which is a ratio of the actual air flow rate at the estimation time to the basic air flow rate; a past air ratio calculation step of calculating a past air ratio which is a ratio of a past actual air flow rate to the basic air flow rate; an air flow rate calculation step of multiplying the basic air flow rate by a ratio of the estimated air ratio to the past air ratio to obtain the air flow rate; Including, the past actual air flow rate is a flow rate of the compressed air flowing into the combustor, the flow rate being determined based at least on an actual air pressure difference between the two points in the intake duct at a time earlier than the estimation time and at the same IGV opening degree as the estimation time; A method for controlling a gas turbine plant.

9. 9. The gas turbine plant control method according to claim 8, In the past air ratio calculation step, the past air ratio for the IGV opening at the time of estimation is calculated using a predetermined opening-past air ratio relationship which is a relationship between the IGV opening and the past air ratio at the time of estimation. A method for controlling a gas turbine plant.

10. 10. The gas turbine plant control method according to claim 9, A relationship setting step is carried out to determine the relationship between the opening degree and the air ratio; In the relationship setting step, Dividing a range in which the opening degrees of the plurality of inlet guide vanes can be changed into a plurality of ranges, and determining divided ranges obtained by dividing the range into a plurality of ranges; A representative point is determined in a coordinate system having the IGV opening and the past air ratio as variables for each of the plurality of divided ranges; a function of the past air ratio having the IGV opening as a variable by connecting the representative points for each of the plurality of divided ranges in the coordinate system with a line; the representative point for each of the plurality of divided ranges is a point that represents the past air ratio for each of the plurality of IGV openings within each of the divided ranges, The function is the opening degree-air ratio past relationship. A method for controlling a gas turbine plant.

11. The gas turbine plant control method according to any one of claims 1 to 10, a fuel flow rate command generating step of generating a fuel flow rate command indicating a total fuel flow rate to be supplied to the combustor based on a required GT output, which is a value required from an outside related to the GT output; a combustion load command generating step of generating a combustion load command indicating a combustion load, which is a parameter positively correlated with an inlet temperature, which is the temperature of the combustion gas at an inlet of the turbine; a load corresponding flow rate ratio calculation step of calculating a load corresponding flow rate ratio, which is a ratio of a flow rate of the first fuel to a flow rate of the fuel supplied to the combustor, in accordance with the combustion load indicated by the combustion load command; Run In the instruction step, instructing the first fuel control valve and the second fuel control valve so that a flow rate of fuel supplied to the combustor becomes the total fuel flow rate generated in the fuel flow rate command generating step and becomes the load corresponding flow rate ratio; when it is determined in the combustion oscillation determination step that the combustion oscillation is occurring and when it is determined in the stable combustion determination step that both the first fuel-air ratio and the second fuel-air ratio are within the stable combustion region, instructing the first fuel control valve and the second fuel control valve so that a flow rate ratio of the flow rate of the first fuel to a flow rate of fuel supplied to the combustor becomes the corrected flow rate ratio used in the process of determining the first fuel-air ratio and the second fuel-air ratio. A method for controlling a gas turbine plant.

12. a gas turbine including: an intake duct through which air can flow; a compressor capable of compressing the air from the intake duct to generate compressed air; a combustor capable of burning fuel in the compressed air to generate combustion gas; and a turbine capable of being driven by the combustion gas; a first fuel control valve capable of adjusting a flow rate of a first fuel which is a part of the fuel supplied to the combustor; a second fuel control valve capable of adjusting a flow rate of a second fuel which is another part of the fuel supplied to the combustor; and Equipped with The compressor includes a compressor rotor rotatable about a rotor axis, a compressor casing that covers the compressor rotor, and an intake air amount adjuster that adjusts a flow rate of air flowing into the compressor casing, the intake air amount regulator has a plurality of inlet guide vanes and a driver capable of changing an opening degree of the plurality of inlet guide vanes, The combustor includes a cylinder in which the fuel can be combusted, a first nozzle capable of injecting the first fuel, a first air flow path frame through which first air, which is a part of the compressed air flowing into the combustor, and the first fuel from the first nozzle can flow, a second nozzle capable of injecting the second fuel, and a second air flow path frame through which second air, which is another part of the compressed air flowing into the combustor, and the second fuel from the second nozzle can flow. In a control device for a gas turbine plant, a fuel flow rate estimator that estimates a fuel flow rate of fuel actually flowing into the combustor; an air flow rate estimator that estimates an air flow rate of the compressed air that actually flows into the combustor; a combustion oscillation determiner for determining whether or not a combustion oscillation occurring state occurs in which the internal pressure fluctuation in the cylinder is greater than a predetermined value; a relationship data storage unit storing relationship data between an increase / decrease amount of the combustion oscillation and an increase / decrease amount of a flow rate ratio of a flow rate of the first fuel to a flow rate of the fuel supplied to the combustor; a corrected flow rate ratio calculator that, when it is determined by the combustion oscillation determiner that the combustion oscillation is occurring, calculates a corrected flow rate ratio that is a flow rate ratio that can avoid the combustion oscillation occurrence state, by using the relationship data stored in the relationship data memory; a burner fuel-air ratio calculator for calculating a first fuel-air ratio, which is a ratio of a flow rate of the first fuel to a flow rate of the first air, and a second fuel-air ratio, which is a ratio of a flow rate of the second fuel to a flow rate of the second air; a stable combustion determiner that determines whether each of the first fuel-air ratio and the second fuel-air ratio is within a predetermined stable combustion region in which there is no possibility of misfire or backfire; an indicator that instructs the first fuel control valve and the second fuel control valve to make a flow rate ratio of the first fuel to a flow rate of fuel supplied to the combustor become the corrected flow rate ratio when the stable combustion determiner determines that both the first fuel-air ratio and the second fuel-air ratio are within the stable combustion region; Equipped with the fuel flow rate estimated by the fuel flow rate estimator is a flow rate of fuel flowing into the combustor, which is determined based on an intake air temperature which is a temperature of air flowing into the compressor casing, an IGV aperture which is an aperture of the plurality of inlet guide vanes, and a GT output which is an output of the gas turbine, the air flow rate estimated by the air flow rate estimator is a flow rate of the compressed air flowing into the combustor, the flow rate being determined based on the intake air temperature, the IGV opening degree, and the GT output; The burner fuel-air ratio calculator includes: determining a flow rate of the first fuel and a flow rate of the second fuel by using the corrected flow ratio and the fuel flow rate estimated by the fuel flow rate estimator; determining a flow rate of the first air and a flow rate of the second air using a predetermined air flow rate ratio between a flow rate of the first air flowing through the first air flow path frame and a flow rate of the second air flowing through the second air flow path frame, and the air flow rate estimated by the air flow rate estimator; A control device for a gas turbine plant.

13. The gas turbine plant control device according to claim 12, When the stable combustion determiner determines that at least one of the first fuel-air ratio and the second fuel-air ratio is not within the stable combustion region, the corrected flow ratio calculator uses the relationship data to determine a new corrected flow ratio that is a flow ratio that can avoid the combustion oscillation occurrence state, The burner fuel-air ratio calculator calculates a new first fuel-air ratio and a new second fuel-air ratio based on the new corrected flow ratio, the stable combustion determiner determines whether or not each of the new first fuel-air ratio and the new second fuel-air ratio is a fuel-air ratio within the stable combustion region. A control device for a gas turbine plant.

14. The gas turbine plant control device according to claim 12, the fuel flow rate estimated by the fuel flow rate estimator is a value obtained by multiplying a basic fuel flow rate by a fuel amount time-varying ratio which is a ratio of an estimated actual fuel flow rate to a past actual fuel flow rate, the basic fuel flow rate is a flow rate of fuel flowing into the combustor, the flow rate being determined based on the intake air temperature, the IGV opening degree, and the GT output at a time when the fuel flow rate is estimated, the estimated actual fuel flow rate is a flow rate of fuel flowing into the combustor, which is determined based at least on an actual pressure difference of fuel before and after the first fuel control valve and an actual pressure difference of fuel before and after the second fuel control valve at the time of the estimation, the past actual fuel flow rate is a flow rate of fuel flowing into the combustor, which is determined based at least on an actual pressure difference of fuel before and after the first fuel control valve and an actual pressure difference of fuel before and after the second fuel control valve at a time that is earlier than the estimation time and at the same GT output as the estimation time, A control device for a gas turbine plant.

15. The gas turbine plant control device according to claim 12, The fuel flow estimator includes: an estimated actual fuel flow rate calculation unit that calculates an estimated actual fuel flow rate, which is a flow rate of fuel flowing into the combustor, based at least on an actual pressure difference of fuel before and after the first fuel control valve and an actual pressure difference of fuel before and after the second fuel control valve at an estimation time when the fuel flow rate is estimated; a fuel ratio calculation unit for calculating a fuel ratio which is a ratio of a basic fuel flow rate to a past actual fuel flow rate at a time earlier than the estimated time; a fuel flow rate calculation unit that multiplies the estimated actual fuel flow rate by the fuel ratio to obtain the fuel flow rate; having the basic fuel flow rate is a flow rate of fuel flowing into the combustor, which is determined based on the intake temperature, the IGV opening degree, and the GT output at the time of the estimation, the past actual fuel flow rate is a flow rate of fuel flowing into the combustor, which is determined based at least on an actual pressure difference of fuel before and after the first fuel control valve and an actual pressure difference of fuel before and after the second fuel control valve at the past time and when the GT output is the same as that at the estimation time; A control device for a gas turbine plant.

16. The gas turbine plant control device according to claim 15, The fuel ratio calculation unit stores in advance an output-fuel ratio past relationship which is a relationship between the GT output at the past time and the fuel ratio at the past time, and calculates the fuel ratio at the past time with respect to the GT output at the time of estimation using the output-fuel ratio past relationship. A control device for a gas turbine plant.

17. The gas turbine plant control device according to claim 16, A relationship setting device is provided for determining the output-fuel ratio relationship, The relationship setting device is Dividing a range of output of the gas turbine between a minimum output and a maximum output of the gas turbine into a plurality of ranges, and determining divided ranges obtained by dividing the range into a plurality of ranges; A representative point is determined in a coordinate system having the GT output and the past fuel ratio as variables for each of the plurality of divided ranges; a function of the past fuel ratio with the GT output as a variable by connecting the representative points for each of the plurality of divided ranges in the coordinate system with lines; The function is the power-fuel ratio relationship, The representative points for each of the plurality of divided ranges are points that represent the past fuel ratios for each of the plurality of GT outputs within each of the divided ranges. A control device for a gas turbine plant.

18. The gas turbine plant control device according to claim 12, The air flow rate estimated by the air flow rate estimator is a value obtained by multiplying a basic air flow rate by an air flow rate temporal change ratio, which is a ratio of an estimated actual air flow rate to a past actual air flow rate, the basic air flow rate is a flow rate of the compressed air flowing into the combustor, which is calculated based on the intake air temperature, the IGV aperture, and the GT output at a time when the fuel flow rate is estimated, the estimated actual air flow rate is a flow rate of the compressed air flowing into the combustor, the flow rate being calculated based at least on an actual air pressure difference between two points in the intake duct at the time of the estimation; the past actual air flow rate is a flow rate of the compressed air flowing into the combustor, which is calculated based at least on an actual pressure difference of air between the two points in the intake duct at a time that is earlier than the estimation time and at the same IGV opening degree as the estimation time; A control device for a gas turbine plant.

19. The gas turbine plant control device according to claim 12, The air flow estimator comprises: a basic air flow rate calculation unit that calculates a basic air flow rate, which is the flow rate of the compressed air flowing into the combustor, based on the intake air temperature, the IGV aperture, and the GT output at the time when the fuel flow rate is estimated; an estimated actual air flow rate calculation unit that calculates an estimated actual air flow rate, which is a flow rate of the compressed air flowing into the combustor, based at least on an actual pressure difference of air between two points in the intake duct at the time of the estimation; an air ratio calculation unit for calculating an air ratio at estimation time, which is a ratio of the actual air flow rate at estimation time to the basic air flow rate; a past air ratio calculation unit for calculating a past air ratio which is a ratio of a past actual air flow rate to the basic air flow rate; an air flow rate calculation unit that calculates the air flow rate by multiplying the basic air flow rate by a ratio of the estimated air ratio to the past air ratio; having the past actual air flow rate is a flow rate of the compressed air flowing into the combustor, the flow rate being determined based at least on an actual air pressure difference between the two points in the intake duct at a time earlier than the estimation time and at the same IGV opening degree as the estimation time; A control device for a gas turbine plant.

20. The gas turbine plant control device according to claim 19, The past air ratio calculation unit stores in advance an opening-past air ratio relationship which is a relationship between the IGV opening and the past air ratio at the past time, and calculates the past air ratio for the IGV opening at the time of the estimation using the opening-past air ratio relationship. A control device for a gas turbine plant.

21. The gas turbine plant control device according to claim 20, A relationship setting device is provided for determining the relationship between the opening degree and the air ratio, The relationship setting device is Dividing a range in which the opening degrees of the plurality of inlet guide vanes can be changed into a plurality of ranges, and determining divided ranges obtained by dividing the range into a plurality of ranges; A representative point is determined in a coordinate system having the IGV opening and the past air ratio as variables for each of the plurality of divided ranges; a function of the past air ratio having the IGV opening as a variable by connecting the representative points for each of the plurality of divided ranges in the coordinate system with a line; the representative point for each of the plurality of divided ranges is a point that represents the past air ratio for each of the plurality of IGV openings within each of the divided ranges, The function is the opening degree-air ratio past relationship. A control device for a gas turbine plant.

22. The gas turbine plant control device according to any one of claims 12 to 21, a fuel flow rate command generator that generates a fuel flow rate command indicating a total fuel flow rate to be supplied to the combustor based on a required GT output, which is an externally required value related to the GT output; a combustion load command generator that generates a combustion load command indicative of a combustion load that is a parameter positively correlated with an inlet temperature that is the temperature of the combustion gas at an inlet of the turbine; a load corresponding flow rate ratio calculator that calculates a load corresponding flow rate ratio, which is a ratio of a flow rate of the first fuel to a flow rate of the fuel supplied to the combustor, in accordance with the combustion load indicated by the combustion load command; Equipped with The indicator is instructing the first fuel control valve and the second fuel control valve so that a flow rate of fuel supplied to the combustor becomes the total fuel flow rate indicated by the fuel flow rate command and becomes the load corresponding flow ratio; when the combustion oscillation determiner determines that the combustion oscillation is occurring and the stable combustion determiner determines that both the first fuel-air ratio and the second fuel-air ratio are within the stable combustion region, instructs the first fuel control valve and the second fuel control valve so that a flow rate ratio of the flow rate of the first fuel to a flow rate of fuel supplied to the combustor becomes the corrected flow rate ratio used in the process of determining the first fuel-air ratio and the second fuel-air ratio. A control device for a gas turbine plant.

23. a gas turbine including: an intake duct through which air can flow; a compressor capable of compressing the air from the intake duct to generate compressed air; a combustor capable of burning fuel in the compressed air to generate combustion gas; and a turbine capable of being driven by the combustion gas; a first fuel control valve capable of adjusting a flow rate of a first fuel which is a part of the fuel supplied to the combustor; a second fuel control valve capable of adjusting a flow rate of a second fuel which is another part of the fuel supplied to the combustor; and Equipped with The compressor includes a compressor rotor rotatable about a rotor axis, a compressor casing that covers the compressor rotor, and an intake air amount adjuster that adjusts a flow rate of air flowing into the compressor casing, the intake air amount regulator has a plurality of inlet guide vanes and a driver capable of changing an opening degree of the plurality of inlet guide vanes, The combustor includes a cylinder in which the fuel can be combusted, a first nozzle capable of injecting the first fuel, a first air flow path frame through which first air, which is a part of the compressed air flowing into the combustor, and the first fuel from the first nozzle can flow, a second nozzle capable of injecting the second fuel, and a second air flow path frame through which second air, which is another part of the compressed air flowing into the combustor, and the second fuel from the second nozzle can flow. In a gas turbine plant control program, a fuel flow rate estimating step of estimating a fuel flow rate of fuel actually flowing into the combustor; an air flow rate estimating step of estimating an air flow rate of the compressed air that actually flows into the combustor; a combustion oscillation determination step of determining whether or not a combustion oscillation occurring state occurs in which the internal pressure fluctuation in the cylinder is greater than a predetermined value; a corrected flow rate ratio calculation step of calculating a corrected flow rate ratio which is a flow rate ratio capable of avoiding the combustion oscillation occurrence state, using relationship data between an amount of increase or decrease in the combustion oscillation and an amount of increase or decrease in a flow rate ratio of the flow rate of the first fuel with respect to a flow rate of the fuel supplied to the combustor, when it is determined in the combustion oscillation determination step that the combustion oscillation occurrence state has occurred; a burner fuel-air ratio calculation step of calculating a first fuel-air ratio which is a ratio of a flow rate of the first fuel to a flow rate of the first air, and a second fuel-air ratio which is a ratio of a flow rate of the second fuel to a flow rate of the second air; a stable combustion determination step of determining whether or not each of the first fuel-air ratio and the second fuel-air ratio is within a predetermined stable combustion region in which there is no possibility of misfire or backfire; an instruction step of instructing the first fuel control valve and the second fuel control valve so that a flow rate ratio of the first fuel to a flow rate of fuel supplied to the combustor becomes the corrected flow rate ratio when it is determined in the stable combustion determination step that both the first fuel-air ratio and the second fuel-air ratio are within the stable combustion region; Run the following on your computer: the fuel flow rate estimated in the fuel flow rate estimating step is a flow rate of fuel flowing into the combustor, which is determined based on an intake air temperature which is a temperature of air flowing into the compressor casing, an IGV aperture which is an aperture of the plurality of inlet guide vanes, and a GT output which is an output of the gas turbine; the air flow rate estimated in the air flow rate estimation step is a flow rate of the compressed air flowing into the combustor, the flow rate being determined based on the intake air temperature, the IGV aperture, and the GT output; In the burner fuel-air ratio calculation step, determining a flow rate of the first fuel and a flow rate of the second fuel by using the corrected flow rate ratio and the fuel flow rate estimated in the fuel flow rate estimation step; determining a flow rate of the first air and a flow rate of the second air by using a predetermined air flow rate ratio between a flow rate of the first air flowing through the first air flow path frame and a flow rate of the second air flowing through the second air flow path frame, and the air flow rate estimated in the air flow rate estimation step; Gas turbine plant control program.

24. The gas turbine plant control program according to claim 23, When it is determined in the stable combustion determination step that at least one of the first fuel-air ratio and the second fuel-air ratio is not within the stable combustion region, a new corrected flow rate ratio that is a flow rate ratio that can avoid the combustion oscillation occurrence state is calculated using the relationship data in the corrected flow rate ratio calculation step S11, In the burner fuel-air ratio calculation step, a new first fuel-air ratio and a new second fuel-air ratio are calculated based on the new corrected flow ratio, In the stable combustion determination step, it is determined whether or not each of the new first fuel-air ratio and the new second fuel-air ratio is a fuel-air ratio within the stable combustion region. Gas turbine plant control program.

25. The gas turbine plant control program according to claim 23, the fuel flow rate estimated in the fuel flow rate estimation step is a value obtained by multiplying a basic fuel flow rate by a fuel amount time change ratio which is a ratio of an estimated actual fuel flow rate to a past actual fuel flow rate, the basic fuel flow rate is a flow rate of fuel flowing into the combustor, the flow rate being determined based on the intake air temperature, the IGV opening degree, and the GT output at a time when the fuel flow rate is estimated, the estimated actual fuel flow rate is a flow rate of fuel flowing into the combustor, which is determined based at least on an actual pressure difference of fuel before and after the first fuel control valve and an actual pressure difference of fuel before and after the second fuel control valve at the time of the estimation, the past actual fuel flow rate is a flow rate of fuel flowing into the combustor, which is determined based at least on an actual pressure difference of fuel before and after the first fuel control valve and an actual pressure difference of fuel before and after the second fuel control valve at a time that is earlier than the estimation time and at the same GT output as the estimation time, Gas turbine plant control program.

26. The gas turbine plant control program according to claim 23, The fuel flow rate estimating step includes: an estimated actual fuel flow rate calculation step of determining an estimated actual fuel flow rate, which is a flow rate of fuel flowing into the combustor, based at least on an actual pressure difference of fuel before and after the first fuel control valve and an actual pressure difference of fuel before and after the second fuel control valve at an estimation time when the fuel flow rate is estimated; a fuel ratio calculation step of calculating a fuel ratio which is a ratio of a basic fuel flow rate to a past actual fuel flow rate at a time earlier than the estimated time; a fuel flow rate calculation step of multiplying the estimated actual fuel flow rate by the fuel ratio to obtain the fuel flow rate; Including, the basic fuel flow rate is a flow rate of fuel flowing into the combustor, which is determined based on the intake temperature, the IGV opening degree, and the GT output at the time of the estimation, the past actual fuel flow rate is a flow rate of fuel flowing into the combustor, which is determined based at least on an actual pressure difference of fuel before and after the first fuel control valve and an actual pressure difference of fuel before and after the second fuel control valve at the past time and when the GT output is the same as that at the estimation time; Gas turbine plant control program.

27. 27. The gas turbine plant control program according to claim 26, In the fuel ratio calculation step, a fuel ratio at the past time relative to the GT output at the time of estimation is calculated using a previously calculated output-fuel ratio past relationship which is a relationship between the GT output and the fuel ratio at the past time. Gas turbine plant control program.

28. 28. The gas turbine plant control program according to claim 27, causing the computer to execute a relationship setting step of determining the output-fuel ratio past relationship; In the relationship setting step, Dividing a range of output of the gas turbine between a minimum output and a maximum output of the gas turbine into a plurality of ranges, and determining divided ranges obtained by dividing the range into a plurality of ranges; A representative point is determined in a coordinate system having the GT output and the past fuel ratio as variables for each of the plurality of divided ranges; a function of the past fuel ratio with the GT output as a variable by connecting the representative points for each of the plurality of divided ranges in the coordinate system with lines; The function is the power-fuel ratio relationship, The representative points for each of the plurality of divided ranges are points that represent the past fuel ratios for each of the plurality of GT outputs within each of the divided ranges. Gas turbine plant control program.

29. The gas turbine plant control program according to claim 23, The air flow rate estimated in the air flow rate estimation step is a value obtained by multiplying a basic air flow rate by an air flow rate temporal change ratio, which is a ratio of an estimated actual air flow rate to a past actual air flow rate, the basic air flow rate is a flow rate of the compressed air flowing into the combustor, the flow rate being determined based on the intake air temperature, the IGV aperture, and the GT output at a time when the fuel flow rate is estimated, the estimated actual air flow rate is a flow rate of the compressed air flowing into the combustor, the flow rate being determined based at least on an actual pressure difference of air between two points in the intake duct at the time of the estimation; the past actual air flow rate is a flow rate of the compressed air flowing into the combustor, the flow rate being determined based at least on an actual air pressure difference between the two points in the intake duct at a time that is earlier than the estimation time and at the same IGV opening degree as the estimation time; Gas turbine plant control program.

30. The gas turbine plant control program according to claim 23, The air flow rate estimation step includes: an estimated actual air flow rate calculation step of calculating an estimated actual air flow rate, which is the flow rate of the compressed air flowing into the combustor, based at least on an actual air pressure difference between two points in the intake duct at a time when the fuel flow rate is estimated; a basic air flow rate calculation step of calculating a basic air flow rate, which is a flow rate of the compressed air flowing into the combustor, based on the intake air temperature, the IGV opening degree, and the GT output at the time of the estimation; an air ratio calculation step of calculating an air ratio at an estimation time, which is a ratio of the actual air flow rate at the estimation time to the basic air flow rate; a past air ratio calculation step of calculating a past air ratio which is a ratio of a past actual air flow rate to the basic air flow rate; an air flow rate calculation step of multiplying the basic air flow rate by a ratio of the estimated air ratio to the past air ratio to obtain the air flow rate; Including, the past actual air flow rate is a flow rate of the compressed air flowing into the combustor, the flow rate being determined based at least on an actual air pressure difference between the two points in the intake duct at a time earlier than the estimation time and at the same IGV opening degree as the estimation time; Gas turbine plant control program.

31. The gas turbine plant control program according to claim 30, In the past air ratio calculation step, the past air ratio for the IGV opening at the time of estimation is calculated using a predetermined opening-past air ratio relationship which is a relationship between the IGV opening and the past air ratio at the time of estimation. Gas turbine plant control program.

32. 32. The gas turbine plant control program according to claim 31, A relationship setting step of determining the relationship between the opening degree and the air ratio is performed by the computer; In the relationship setting step, Dividing a range in which the opening degrees of the plurality of inlet guide vanes can be changed into a plurality of ranges, and determining divided ranges obtained by dividing the range into a plurality of ranges; A representative point is determined in a coordinate system having the IGV opening and the past air ratio as variables for each of the plurality of divided ranges; a function of the past air ratio having the IGV opening as a variable by connecting the representative points for each of the plurality of divided ranges in the coordinate system with a line; the representative point for each of the plurality of divided ranges is a point that represents the past air ratio for each of the plurality of IGV openings within each of the divided ranges, The function is the opening degree-air ratio past relationship. Gas turbine plant control program.

33. 33. The gas turbine plant control program according to any one of claims 23 to 32, a fuel flow rate command generating step of generating a fuel flow rate command indicating a total fuel flow rate to be supplied to the combustor based on a required GT output, which is a value required from an outside related to the GT output; a combustion load command generating step of generating a combustion load command indicating a combustion load, which is a parameter positively correlated with an inlet temperature, which is the temperature of the combustion gas at an inlet of the turbine; a load corresponding flow rate ratio calculation step of calculating a load corresponding flow rate ratio, which is a ratio of a flow rate of the first fuel to a flow rate of the fuel supplied to the combustor, in accordance with the combustion load indicated by the combustion load command; causing the computer to execute In the instruction step, instructing the first fuel control valve and the second fuel control valve so that a flow rate of fuel supplied to the combustor becomes the total fuel flow rate generated in the fuel flow rate command generating step and becomes the load corresponding flow rate ratio; when it is determined in the combustion oscillation determination step that the combustion oscillation is occurring and when it is determined in the stable combustion determination step that both the first fuel-air ratio and the second fuel-air ratio are within the stable combustion region, instructing the first fuel control valve and the second fuel control valve so that a flow rate ratio of the flow rate of the first fuel to a flow rate of fuel supplied to the combustor becomes the corrected flow rate ratio used in the process of determining the first fuel-air ratio and the second fuel-air ratio. Gas turbine plant control program.

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