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

Abstract

A gas turbine control device of the present disclosure controls a gas turbine in which a combustor is configured in a state where a plurality of fuel supply nozzles for supplying fuel are separated into a first group and a second group. This device, on the basis of the operating state of the gas turbine, calculates a control parameter base index relating to the ratio of the amount of fuel supplied by the second group to the amount of fuel supplied by the first group. The base index is corrected using a correction value calculated on the basis of the operating state of the gas turbine. The amounts of fuel supplied by the first group and the second group are each controlled on the basis of a control parameter obtained by correcting the base index using the correction value. This correction value is calculated so that the absolute value thereof decreases to zero after the gas turbine has been started up and a prescribed length of time has passed since load addition to the gas turbine.

Description

[Technical Field]

[0001] The present disclosure relates to a gas turbine control device, a gas turbine control method, and a gas turbine control program. This application claims priority based on Japanese Patent Application No. 2022-069362, filed with the Japan Patent Office on April 20, 2022, the contents of which are incorporated herein by reference. [Background technology]

[0002] Gas turbines equipped with a compressor and a combustor are known. In these gas turbines, air taken in through an air intake is compressed by the compressor to generate compressed air, and fuel is supplied to the compressed air and combusted in the combustor to generate high-temperature, high-pressure combustion gas. The gas turbine has a turbine configured with a plurality of turbine stator vanes and turbine rotor blades arranged alternately in a passage within a casing. The turbine rotor blades are driven by the combustion gas generated in the combustor, thereby rotating a rotor connected to, for example, a generator. The combustion gas that drives the turbine is converted to static pressure by a diffuser and then discharged to the outside.

[0003] This type of gas turbine is designed on the assumption that the temperature of fuel supplied to the combustor is within a predetermined range. For example, when the fuel temperature is within the predetermined range, the gas turbine applies an exhaust gas-compatible combustion mode, thereby controlling the exhaust gas from the gas turbine to meet a predetermined standard. However, when the fuel temperature is outside the predetermined range, the exhaust gas-compatible combustion mode is not applied, and an initial startup mode suitable for low-temperature fuel is applied. In response to this, Patent Document 1 discloses a gas turbine control method for applying the exhaust gas-compatible combustion mode even when the fuel temperature is outside the predetermined range. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5336346 Summary of the Invention [Problem to be solved by the invention]

[0005] When a load is added (introduced) and increased during the startup of a gas turbine, combustion oscillation can occur in the gas turbine. Therefore, in conventional fuel supply control for the combustor of a gas turbine, combustion parameters are controlled to ensure a margin for combustion oscillation. However, the margin for combustion depth decreases as the fuel temperature decreases, making combustion oscillation more likely to occur. Conventionally, the startup time of a gas turbine was long enough that the fuel temperature had risen to a certain level when the load was added, reducing the risk of combustion oscillation. However, in recent years, with the increase in power generation from renewable energy sources in power grids, gas turbines capable of rapid startup are required. During rapid startup, load addition may occur before the fuel temperature has risen sufficiently, increasing the risk of combustion oscillation and, in some cases, even causing the gas turbine to trip.

[0006] At least one embodiment of the present disclosure has been made in consideration of the above-described circumstances, and has an object to provide a gas turbine control device, a gas turbine control method, and a gas turbine control program that are capable of suppressing the occurrence of combustion oscillation even when a load is added while the fuel temperature is low at startup. [Means for solving the problem]

[0007] In order to solve the above problem, a gas turbine control device according to at least one embodiment of the present disclosure includes: A gas turbine control device for controlling a gas turbine in which a combustor is configured in a form in which a plurality of fuel supply nozzles for supplying fuel are divided into a first group and a second group, a base index calculation unit that calculates a base index of a control parameter related to a ratio of the fuel supply amount by the second group to the fuel supply amount by the first group based on an operating state of the gas turbine; a correction value calculation unit that calculates a correction value for correcting the base index based on an operating state of the gas turbine; a fuel control unit for controlling the fuel supply amounts of the first group and the second group based on the control parameters obtained by correcting the base index using the correction value; Equipped with The correction value calculation unit calculates the correction value such that the absolute value of the correction value decreases to zero when a predetermined period of time has elapsed since load injection into the gas turbine after the gas turbine has been started.

[0008] In order to solve the above problem, a gas turbine control method according to at least one embodiment of the present disclosure includes: A gas turbine control method for controlling a gas turbine having a combustor configured in a form in which a plurality of fuel supply nozzles for supplying fuel are divided into a first group and a second group, the method comprising: calculating a base index of a control parameter related to a ratio of the fuel supply amount by the second group to the fuel supply amount by the first group based on an operating state of the gas turbine; calculating a correction value for correcting the base index based on an operating state of the gas turbine; controlling the fuel supply amounts of the first group and the second group based on the control parameters obtained by correcting the base index using the correction value; Equipped with In the step of calculating the correction value, the correction value is calculated such that the absolute value of the correction value decreases to zero when a predetermined period of time has elapsed since load incorporation into the gas turbine after the gas turbine has been started.

[0009] In order to solve the above problem, a gas turbine control program according to at least one embodiment of the present disclosure includes: A gas turbine control program for controlling a gas turbine having a combustor configured in a form in which a plurality of fuel supply nozzles for supplying fuel are divided into a first group and a second group, the program comprising: Using a computer, calculating a base index of a control parameter related to a ratio of the fuel supply amount by the second group to the fuel supply amount by the first group based on an operating state of the gas turbine; calculating a correction value for correcting the base index based on an operating state of the gas turbine; controlling the fuel supply amounts of the first group and the second group based on the control parameters obtained by correcting the base index using the correction value; is executable, In the step of calculating the correction value, after the gas turbine is started, when a predetermined period has elapsed since load incorporation of the gas turbine, the correction value is calculated. Absolute value of The correction value is calculated so that decreases to zero. [Effects of the Invention]

[0010] According to at least one embodiment of the present disclosure, it is possible to provide a gas turbine control device, a gas turbine control method, and a gas turbine control program that are capable of suppressing the occurrence of combustion oscillation even when a load is added while the fuel temperature is low at startup. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic configuration diagram of a gas turbine according to an embodiment. [Figure 2] FIG. 2 is a schematic configuration diagram of a combustor in the gas turbine of FIG. [Figure 3] FIG. 3 is a cross-sectional schematic view of FIG. 2. [Figure 4] FIG. 1 is a block diagram illustrating a gas turbine control device according to an embodiment. [Figure 5] 5 is a process flow diagram of the fuel control unit of FIG. 4 in a vibration suppression mode. [Figure 6] This is an example of the first function when KMB is used as the control parameter. [Figure 7]This is an example of the second function when KMB is used as the control parameter. [Figure 8] This is an example of the third function when KMB is used as the control parameter. [Figure 9] This is an example of the first function when the top hat ratio is used as the control parameter. [Figure 10] 10 is an example of the second function when the top hat ratio is used as the control parameter. [Figure 11] This is an example of the third function when the top hat ratio is used as the control parameter. [Figure 12] FIG. 6 is a process flow diagram of a gain correction unit in FIG. 5. [Figure 13] FIG. 6 is a diagram illustrating a fourth function of FIG. 5. [Figure 14] FIG. 6 is a diagram illustrating a fifth function of FIG. 5. [Figure 15] FIG. 6 is a diagram illustrating a sixth function of FIG. 5. [Figure 16] 1 is a flowchart illustrating a gas turbine start-up method according to an embodiment. [Figure 17] 4 is a time chart showing time variations of various indices related to the operating state of the gas turbine at startup. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, several embodiments of the present invention will be described with reference to the accompanying drawings. However, the configurations described as the embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present invention.

[0013] First, the configuration of a gas turbine GT that is a control target of a gas turbine control device according to at least one embodiment of the present invention will be described with reference to Figures 1 to 3. Figure 1 is a schematic configuration diagram of a gas turbine GT according to one embodiment, Figure 2 is a schematic configuration diagram of a combustor 2 in the gas turbine GT of Figure 1, and Figure 3 is a schematic cross-sectional view of Figure 2.

[0014] As shown in Fig. 1, the gas turbine GT includes a compressor 1, a combustor 2, and a turbine 3. A rotor 4 is disposed so as to penetrate through the center of the compressor 1, the combustor 2, and the turbine 3. The compressor 1, the combustor 2, and the turbine 3 are arranged in sequence from the front to the rear of the air flow along the axis R of the rotor 4. In the following description, the axial direction refers to a direction parallel to the axis R, and the circumferential direction refers to a direction around the axis R as the center.

[0015] The compressor 1 is configured to compress air to generate compressed air. The compressor 1 has compressor stator vanes 13 and compressor rotor blades 14 provided in a compressor casing 12 having an air intake 11 for taking in air. The compressor stator vanes 13 are attached to the compressor casing 12 side and are arranged in multiple rows in the circumferential direction. The compressor rotor blades 14 are attached to the rotor 4 side and are arranged in multiple rows in the circumferential direction. The compressor stator vanes 13 and compressor rotor blades 14 are arranged alternately along the axial direction.

[0016] The combustor 2 is configured to generate high-temperature, high-pressure combustion gas by supplying fuel to the compressed air compressed by the compressor 1. The combustor 2 includes, as a combustion tube, an inner tube 21 that mixes and burns the compressed air with fuel, a transition piece 22 that guides the combustion gas from the inner tube 21 to the turbine 3, and an outer tube 23 that covers the outer periphery of the inner tube 21 and forms an air passage 26 (see FIG. 2 ) that guides the compressed air from the compressor 1 to the inner tube 21. A plurality of combustors 2 (e.g., 16 combustors 2) are arranged side by side in the circumferential direction of a combustor casing 24. This type of combustor 2 configuration is called a cannular type.

[0017] As shown in FIGS. 2 and 3 , each combustor 2 is provided with a pilot nozzle 251, a main nozzle 252, and a top hat nozzle 253 as nozzles for supplying fuel. One pilot nozzle 251 is provided at the center of the inner cylinder 21. The pilot nozzle 251 is connected to a fuel port 251a provided on the outside of the combustor 2 via a pilot fuel line 251b. A pilot fuel supply valve 251c is provided on the pilot fuel line 251b. That is, by opening the pilot fuel supply valve 251c, fuel is supplied to the pilot nozzle 251 and the fuel is injected from the pilot nozzle 251. The pilot fuel supply valve 251c is configured to vary the amount of fuel supplied when it is open. On the other hand, by closing the pilot fuel supply valve 251c, the supply of fuel to the pilot nozzle 251 is stopped, and fuel injection from the pilot nozzle 251 is stopped. The pilot fuel supply valve 251c is driven to open and close by a pilot fuel supply valve drive unit 53 (see FIG. 4) such as an actuator or a motor.

[0018] A plurality of main nozzles 252 (eight in this embodiment) are provided adjacent to each other in the circumferential direction around the pilot nozzle 251 inside the inner cylinder 21. These main nozzles 252 are configured into a plurality of groups. In this embodiment, as shown in Fig. 3, the eight main nozzles 252 are configured to include group A including three main nozzles 252 adjacent to each other in the circumferential direction, and group B including the remaining five main nozzles 252 adjacent to each other in the circumferential direction.

[0019] In this embodiment, the case where the main nozzles 252 are divided into two groups (group A and group B) is illustrated, but the number of groups into which the main nozzles 252 are divided may be two or more. In this embodiment, the case where the number of main nozzles 252 belonging to group B (five nozzles) is greater than the number of main nozzles 252 belonging to group A (three nozzles) is illustrated, but the relationship in magnitude between the numbers of main nozzles 252 belonging to groups A and B may be arbitrary. In this embodiment, the case where the numbers of main nozzles 252 belonging to groups A and B are different from each other is illustrated, but the numbers of main nozzles 252 belonging to both groups may be the same.

[0020] Each of the main nozzles 252 divided into groups A and B is connected to a fuel port 252a extending outside the combustor 2 via a main fuel line 252b corresponding to the corresponding group. A main fuel supply valve 252c is provided in each main fuel line 252b. That is, by opening each main fuel supply valve 252c, fuel is supplied to the main nozzles 252 of each group, and fuel is injected from the main nozzles 252 of each group. Each main fuel supply valve 252c is configured to be able to vary the amount of fuel supplied when it is open. On the other hand, by closing each main fuel supply valve 252c, fuel supply to the main nozzles 252 of each group is stopped, and fuel injection from the main nozzles 252 of each group is stopped. The main fuel supply valves 252c of each group are driven to open and close by a group A main fuel supply valve drive unit 54 and a group B main fuel supply valve drive unit 55 (see FIG. 4), such as an actuator or a motor. Furthermore, a swirler vane 252d is provided on the outside of the main nozzle 252, and the periphery thereof is covered with a burner cylinder 252e.

[0021] A plurality of top hat nozzles 253 (16 in this embodiment) are provided adjacent to each other in the circumferential direction around the main nozzle 252 along the inner circumferential surface of the external casing 23. The top hat nozzles 253 are connected to fuel ports 253a provided on the outside of the combustor 2 via top hat fuel lines 253b. A top hat fuel supply valve 253c is provided on the top hat fuel line 253b. When the top hat fuel supply valve 253c is opened, fuel is supplied to the top hat nozzle 253 and the fuel is injected from the top hat nozzle 253. The top hat fuel supply valve 253c is configured to vary the amount of fuel supplied when it is open. When the top hat fuel supply valve 253c is closed, the supply of fuel to the top hat nozzle 253 is stopped, and fuel injection from the top hat nozzle 253 is stopped. The top hat fuel supply valve 253c is driven to open and close by a top hat fuel supply valve drive unit 57 (see FIG. 4) such as an actuator or a motor.

[0022] In the combustor 2 having such a configuration, as shown in FIG. 2 , an airflow of high-temperature, high-pressure compressed air flows into the air passage 26. This compressed air is mixed with fuel injected from the top hat nozzle 253 to generate a fuel mixture, which flows into the inner cylinder 21. In the inner cylinder 21, the fuel mixture is mixed with fuel injected from the main nozzles 252, and the swirler vanes 252d and the burner cylinders 252e create a swirling flow of premixed air, which flows into the transition piece 22. The fuel mixture is also mixed with fuel injected from the pilot nozzle 251, ignited by a pilot flame (not shown), and combusted as combustion gas, which is ejected into the transition piece 22. At this time, part of the combustion gas is ejected into the transition piece 22 so as to diffuse around, accompanied by a flame, and the premixed air from the burner cylinders 252e of each main nozzle 252 is ignited and combusted. That is, the diffusion flame of the fuel injected from the pilot nozzle 251 performs flame stabilization to stabilize the combustion of the premixed air-fuel from the burner tube 252 e of each main nozzle 252 .

[0023] Returning to FIG. 1 , the turbine 3 generates rotational power from combustion gas combusted in the combustor 2. The turbine 3 includes turbine stator vanes 32 and turbine rotor blades 33 in a turbine casing 31. The turbine stator vanes 32 are attached to the turbine casing 31 and arranged in a plurality of rows in the circumferential direction. The turbine rotor blades 33 are attached to the rotor 4 and arranged in a plurality of rows in the circumferential direction. The turbine stator vanes 32 and turbine rotor blades 33 are arranged alternately in the axial direction. An exhaust chamber 34 having an exhaust diffuser 34a continuous with the turbine 3 is provided at the rear of the turbine casing 31.

[0024] The rotor 4 has an end on the compressor 1 side supported by a bearing 41 and an end on the exhaust chamber 34 side supported by a bearing 42, and is rotatable about an axis R. A drive shaft of a generator (not shown) is connected to the end of the compressor 1 on the bearing 41 side.

[0025] In such a gas turbine GT, air taken in through an air intake 11 of the compressor 1 passes through a plurality of compressor stator vanes 13 and compressor rotor blades 14 and is compressed to become high-temperature, high-pressure compressed air. Fuel is supplied to this compressed air through a pilot nozzle 251, a main nozzle 252, and a top hat nozzle 253 of the combustor 2, generating high-temperature, high-pressure combustion gas. This combustion gas then passes through turbine stator vanes 32 and turbine rotor blades 33 of the turbine 3, driving the rotor 4 to rotate, and power is generated by imparting rotational power to a generator connected to the rotor 4. The exhaust gas that has driven the rotor 4 to rotate is converted to static pressure in an exhaust diffuser 34a in an exhaust chamber 34 and then released into the atmosphere.

[0026] Next, a gas turbine control device 50 for controlling the gas turbine GT having the above configuration will be described. Fig. 4 is a block diagram showing the gas turbine control device 50 according to one embodiment.

[0027] The gas turbine control device 50 is configured to control the gas turbine GT, and is configured with, for example, a microcomputer. As shown in FIG. 4, the gas turbine control device 50 includes a fuel control unit 51 and a storage unit 52. The gas turbine control device 50 stores information about the operating state of the gas turbine GT (for example, the load index CLCSO of the gas turbine GT and the intake air temperature degree T1C, etc.) is input, the fuel control unit 51 controls a pilot fuel supply valve drive unit 53, an A group main fuel supply valve drive unit 54, a B group main fuel supply valve drive unit 55, and a top hat fuel supply valve drive unit 57 in accordance with programs and data stored in advance in the storage unit 52, thereby supplying fuel to the pilot nozzle 251, the main nozzle 252, and the top hat nozzle 253.

[0028] The gas turbine control device 50 can implement a start-up mode, a vibration suppression mode, and a normal mode as operation modes for controlling the gas turbine GT, as will be described later with reference to Figs. 16 and 17. The start-up mode is an operation mode for increasing the rotation speed of the gas turbine GT, which is in a stopped state, to the rated rotation speed when the gas turbine GT is started, to make it possible to add a load. The vibration suppression mode is an operation mode for suppressing combustion vibration, which is at a high risk of occurring if the fuel temperature is low when a load is added to the gas turbine GT after the start-up mode. The normal mode is an operation mode for suppressing combustion vibration, which is at a high risk of occurring if the fuel temperature is low, when a load is added to the gas turbine GT after the start-up mode. restraint This is the operating mode for normal operation of the gas turbine GT after passing through the normal operation mode.

[0029] The gas turbine GT configured as described above has, as a configuration for supplying fuel, the pilot nozzle 251, the main nozzles 252 divided into groups A and B, and the top hat nozzles 253, but the fuel control unit 51 divides these configurations into a first group G1 and a second group G2, and performs fuel supply control using the ratio of the fuel supply amount by the second group G2 to the fuel supply amount by the first group G1 as a control parameter P. For example, when the main nozzles 252 divided into groups A and B are treated as the first group G1 and the second group G2, respectively, KMB, which is the ratio of the fuel supply amount MB of the main nozzles 252 belonging to group B to the fuel supply amount MA of the main nozzles 252 belonging to group A, is treated as the control parameter P. Specifically, KMB is defined by the following equation when the total number of main nozzles 252 is eight as described above, and the numbers of main nozzles 252 belonging to groups A and B are three and five, respectively. KMB=MB / (MA+MB)×(8 / 5)×100 KMB defined in this way is an index that becomes "100%" when an equal amount of fuel supply is distributed to each of the multiple main nozzles 252 (that is, when MA:MB=3:5).

[0030] The first group G1 and the second group G2 can be arbitrarily selected from the pilot nozzle 251, the main nozzles 252 divided into group A and group B, and the top hat nozzle 253. For example, by selecting the main nozzles 252 including group A and group B as the first group G1 and the top hat nozzles 253 as the second group G2, the ratio of the amount of fuel supplied between the main nozzles 252 and the top hat nozzles 253 can be treated as the control parameter P.

[0031] Next, a configuration for calculating the control parameter P by the fuel control unit 51 in each operation mode will be described.

[0032] First, in the startup mode, the fuel control unit 51 controls the supply of fuel to five of the eight main nozzles 252 belonging to group B. At this time, the three main nozzles 252 belonging to group A are supplied with the fuel that is supplied to the eight main nozzles 252 in the normal mode, so that the fuel supply amount is controlled to be large. This allows the main nozzles 252 belonging to group A to generate a large flame, enabling rapid startup.

[0033] In the oscillation suppression mode, the fuel control unit 51 calculates a base index Pbase and a correction value Pamd for a control parameter P such as the KMB or TH ratio, and treats the result of correcting the base index Pbase with the correction value Pamd as the control parameter P. This makes it possible to shift the operating state of the gas turbine GT from a state in which combustion oscillation is likely to occur, even when the fuel temperature is low, and ensures control margin even during rapid startup when the fuel temperature is low, making it possible to effectively suppress combustion oscillation. In the normal mode, control is performed that corresponds to the case where the correction value Pamd in the vibration suppression mode is set to 0. In other words, the base index Pbase calculated in the vibration suppression mode corresponds to the control parameter P in the normal mode itself.

[0034] 5 is a process flow diagram in the vibration suppression mode of the fuel control unit 51 of FIG. 4. The fuel control unit 51 includes a base index calculation unit 59 and a correction value calculation unit 56.

[0035] The base index calculation unit 59 is configured to calculate a base index Pbase related to the control parameter P based on the operating state of the gas turbine GT. The base index calculation unit 59 acquires, for example, a load index CLCSO of the gas turbine GT as the operating state of the gas turbine GT. These are acquired based on various sensors and control signals installed in the gas turbine GT. The relationship between the operating state of the gas turbine GT and the base index Pbase is specified in advance as a function, and the base index calculation unit 59 calculates the base index Pbase by inputting the operating state of the gas turbine GT into this function.

[0036] The correction value calculation unit 56 is configured to calculate a correction value Pamd for correcting the base index Pbase calculated by the base index calculation unit 59, based on the operating state of the gas turbine GT. In this embodiment, the operating state of the gas turbine GT input to the correction value calculation unit 56 includes a load index CLCSO corresponding to the load of the gas turbine GT, and an intake air temperature of the gas turbine GT. degree The relationship between the operating state of the gas turbine GT and the correction value Pamd is specified in advance as at least one function, and the correction value Pamd is calculated so as to become zero when a predetermined period of time has elapsed since the load was added. Furthermore, the intake temperature degree For example, as shown in FIG. 1, T1C is detected by a temperature sensor provided in the intake chamber 11 of the gas turbine GT.

[0037] 5, the specific processing flow for calculating the correction value Pamd will be explained. The load index CLCSO and the intake air temperature T1C acquired as the operating state of the gas turbine GT are input to a first function FX1, a second function FX2, and a third function FX3. The first function FX1, the second function FX2, and the third function FX3 are read out from the storage unit 52 and stored in advance.

[0038] The load index CLCSO acquired as the operating state of the gas turbine GT is input to the first function FX1, and a first correction value Pamd1 is output. The first function FX1 is set in advance as a function indicating the correlation between the load index CLCSO and the first correction value Pamd1, and is saved in the storage unit 52. The correction value calculation unit 56 reads out the first function FX1 from the storage unit 52, and calculates the first correction value Pamd1 by inputting the load index CLCSO acquired as the operating state of the gas turbine GT.

[0039] The load index CLCSO acquired as the operating state of the gas turbine GT is input to the second function FX2, and a second correction value Pamd2 is output. The second function FX2 is set in advance as a function indicating the correlation between the load index CLCSO and the second correction value Pamd2, and is saved in the storage unit 52. The correction value calculation unit 56 reads out the second function FX2 from the storage unit 52, and calculates the second correction value Pamd2 by inputting the load index CLCSO acquired as the operating state of the gas turbine GT.

[0040] The intake-air temperature T1C acquired as an operating state of the gas turbine GT is input to the third function FX3, and a third correction value Pamd3 is output. The third function FX3 is set in advance as a function indicating the correlation between the intake-air temperature T1C and the third correction value Pamd3, and is saved in the storage unit 52. The correction value calculation unit 56 reads out the third function FX3 from the storage unit 52, and calculates the third correction value Pamd3 by inputting the intake-air temperature T1C acquired as an operating state of the gas turbine GT.

[0041] The correction value calculation unit 56 calculates a provisional correction value Pamd' based on the first correction value Pamd1, the second correction value Pamd2, and the third correction value Pamd3. As shown in Fig. 5, the provisional correction value Pamd' is calculated as the difference between the first correction value Pamd1 and the multiplication result of the second correction value Pamd2 and the third correction value Pamd3.

[0042] 6 to 8 show examples of the first to third functions FX1 to FX3 when KMB is used as the control parameter P. As shown in FIG. 6, the first function FX1 is set so that the first correction value Pamd1 increases with respect to the load index CLCSO within a range corresponding to a target load band for which correction is desired. In this embodiment, the first function FX1 is set so that the first correction value Pamd1 is zero when the load index CLCSO is between C0 and C1, gradually increases between C1 and C2, is substantially constant at "5" between C2 and C3, gradually decreases between C3 and C4, and is substantially constant at "4" above C4.

[0043] 7, the second function FX2 is set so that the second correction value Pamd2 increases with respect to the load index CLCSO within a range corresponding to a target load band for which correction is desired. In this embodiment, the second function FX2 is set so that the second correction value Pamd2 is substantially constant at "0" when the load index CLCSO is C5 or less, gradually decreases between C5 and C6, and is substantially constant at "-4" when the load index CLCSO is C6 or more.

[0044] The third function FX3 is set so that the third correction value Pamd3 increases with respect to the intake air temperature T1C within a range corresponding to a target temperature range to be corrected, as shown in Fig. 8. In this embodiment, the third function FX3 is set so that the third correction value Pamd3 gradually increases when the intake air temperature T1C is equal to or lower than T1, so that the third correction value Pamd3 increases more rapidly between T1 and T2, and so that the third correction value Pamd3 remains substantially constant when the intake air temperature T1C is equal to or higher than T2.

[0045] 9 to 11 are examples of the first function FX1 to the third function FX3 when the TH ratio is used as the control parameter P. In this case, the first function FX1 is expressed as follows, as shown in FIG. ,negativeThe first correction value Pamd1 is set to be substantially constant "-1.5" when the load index CLCSO is C7 or less, gradually decreasing between C7 and C8, and substantially constant "-2.5" when the load index CLCSO is C8 or more. The second function FX2 is set to be substantially constant "0" regardless of the load index CLCSO, as shown in FIG. 10. The third function FX3 is set to be substantially constant "0" regardless of the intake air temperature T1C, as shown in FIG. 11.

[0046] The provisional correction value Pamd' calculated using the first function FX1 to the third function FX3 in this way is multiplied by the gain correction coefficient G calculated by the gain correction unit 60, and is adjusted to become zero at the timing when a predetermined period has elapsed since the load was introduced. Here, Fig. 12 is a process flow diagram of the gain correction unit 60 in Fig. 5, and Figs. 13 to 15 are diagrams showing the fourth function FX4 to the sixth function FX6 in Fig. 5.

[0047] The gain correction unit 60 inputs the intake-air temperature T1C, acquired as an operating state of the gas turbine GT, into a fourth function FX4, to calculate the required temperature-rise time Ti required for the fuel temperature to rise sufficiently (for example, the time required for the fuel temperature to reach a preset target temperature). The relationship between the intake-air temperature T1C and the required temperature-rise time Ti is stored in advance in the storage unit 52 as the fourth function FX4. For example, as shown in FIG. 13, the fourth function FX4 is defined so that the required temperature-rise time Ti monotonically increases with the intake-air temperature T1C. The gain correction unit 60 reads out the fifth function FX5 stored in the storage unit 52, and inputs the intake-air temperature T1C, acquired as an operating state of the gas turbine GT, into the fifth function FX5 to calculate the required temperature-rise time Ti.

[0048] The gain correction unit 60 also calculates a required temperature rise time correction value Tamd for correcting the required temperature rise time Ti based on the temperature of the gas turbine GT (second-stage DC (disk cavity) temperature Tgt) acquired as the operating state of the gas turbine GT at startup. The second-stage DC temperature Tgt is acquired as a detection value by a temperature sensor installed in a cavity of the second-stage disk of the gas turbine GT. The relationship between the second-stage DC temperature Tgt and the required temperature rise time correction value Tamd is stored in advance in the storage unit 52 as a fifth function FX5. For example, as shown in FIG. 14, the fifth function FX5 is defined so that the required temperature rise time correction value Tamd monotonically increases with the second-stage DC temperature Tgt. The gain correction unit 60 reads out the fifth function FX5 stored in the storage unit 52 and inputs the second-stage DC temperature Tgt into a sixth function FX6 to calculate the required temperature rise time correction value Tamd.

[0049] The gain correction unit 60 calculates the count reference value Ciref as a result of correction by adding the required temperature rise time Ti to the required temperature rise time correction value Tamd. 4 Seki As can be seen from a comparison between the function FX4 and the fifth function FX5, the required temperature rise time Ti calculated from the fourth function FX4 is a negative value with an absolute value larger than that of the required temperature rise time corrected value Tamd calculated from the fifth function FX5, and therefore the count reference value Ciref is typically a negative value. The count unit 62 counts up the count reference value Ciref by a unit value per unit time (for example, by counting up by 1 every second), and outputs the count index Ci.

[0050] The count index Ci output from the count unit 62 is input to a sixth function FX6. The relationship between the count index Ci and the gain correction coefficient G is stored in advance as the sixth function FX6 in the storage unit 52. As shown in FIG. 15 , the sixth function FX6 is set so that when the count index Ci is a sufficiently small negative value, the gain correction coefficient G is a substantially constant value of "1," and decreases monotonically as the count index Ci approaches zero, until the gain correction coefficient G becomes "zero."

[0051] In this way, the gain correction coefficient G calculated by the gain correction unit 60 is multiplied by the provisional correction value Pamd' described above, thereby obtaining the correction value Pamd that changes so that its absolute value becomes zero when a predetermined period has elapsed since the load was added. As a result, when the fuel temperature rises and the risk of combustion oscillation decreases, it is possible to smoothly transition to control of the gas turbine GT (normal mode) based on the original base index Pbase. In FIG. 5, a limiter 64 is provided to prevent the correction value Pamd from deviating from a preset allowable range.

[0052] Next, a method for starting up the gas turbine GT by the gas turbine control device 50 having the above configuration will be described. Fig. 16 is a flowchart showing a gas turbine start-up method according to one embodiment, and Fig. 17 is a time chart showing the time variations of various indexes related to the operating state of the gas turbine GT at startup.

[0053] First, the gas turbine control device 50 determines whether or not the gas turbine GT has been started up (step S100). In step S100, for example, whether or not the gas turbine GT has been started up is determined based on whether or not a startup switch provided on the gas turbine GT has been turned ON by an operator. When the gas turbine GT has been started up (step S100: YES), the gas turbine control device 50 acquires the operating state of the gas turbine GT at the time of start-up (step S101), and implements the start-up mode as the operating mode of the gas turbine GT (step S102). The operating state acquired in step S101 includes at least the fuel temperature at the time of start-up, and FIG. 17 shows that the fuel temperature Tf is sufficiently lower than the target fuel temperature Tf0 at time t1, which is the time of start-up.

[0054] In the startup mode performed in step S102, startup operation is performed by supplying fuel to three of the eight main nozzles 252 that belong to group A. At this time, fuel is supplied to the three main nozzles 252 that belong to group A in the normal mode, which increases the amount of fuel supplied compared to the normal mode, and the flame that is generated is also larger. As a result, as shown in Fig. 17, when the gas turbine GT is started at time t1, the rotation speed of the gas turbine GT gradually increases and reaches the rated rotation speed at time t2.

[0055] Next, the gas turbine control device 50 determines whether or not load addition has been performed on the gas turbine GT (step S103). Load addition on the gas turbine GT at start-up is performed after the rotational speed of the gas turbine GT has increased to the rated rotational speed. Fig. 17 shows a state in which load addition on the gas turbine GT is performed at time t3 after the rotational speed of the gas turbine GT has reached the rated rotational speed at time t2.

[0056] When a load is added to the gas turbine GT (step S103: YES), the gas turbine control device 50 transitions the operation mode of the gas turbine GT to the vibration suppression mode (step S104). In the vibration suppression mode, as described above, the gas turbine GT is controlled based on the control parameter P (the ratio of the amount of fuel supplied by the second group G2 to the amount of fuel supplied by the first group G1) obtained by correcting the base index Pbase calculated by the base index calculation unit 59 with the correction value Pamd calculated by the correction value calculation unit 56. In FIG. 17, the KMB and TH ratio (the result of correcting the base index Pbase with the correction value Pamd) are each indicated by a solid line as the control parameter P. For comparison, in FIG. 17, the control parameter before correction with the correction value Pamd (i.e., the base index Pbase itself) is indicated by a dashed line. For KMB, which is the control parameter P, a correction value Pamd having a positive sign is obtained by using the first function FX1 to the third function FX3 shown in Figures 6 to 8, so the control parameter P is corrected so that it becomes larger than the base index Pbase (the solid line is larger than the dashed line). On the other hand, for the TH ratio, which is the control parameter P, a correction value Pamd having a negative sign is obtained by using the first function FX1 to the third function FX shown in Figures 9 to 11, so the control parameter P is corrected so that it becomes smaller than the base index Pbase (the dashed line). twist solid line but In this way, the control parameter P is determined by correcting the base index Pbase, which is calculated based on the operating state, using the correction value Pamd, which makes it possible to shift the operating state of the gas turbine GT away from a state in which combustion oscillation is likely to occur, ensuring control margin even during rapid start-up when the fuel temperature is low, and effectively suppressing combustion oscillation.

[0057] As described above, the correction value Pamd is calculated so that its absolute value decreases to zero at time t4, a predetermined period Tmd after the load is introduced (time t3). Therefore, in FIG. 17, the correction value Pamd(ΔKMB) with a positive sign corresponding to KMB gradually decreases to zero at time t4. Meanwhile, the correction value Pamd(ΔTH) with a negative sign corresponding to the TH ratio gradually increases to zero at time t4.

[0058] Next, the gas turbine control device 50 determines whether a predetermined period Tmd has elapsed since the load was introduced (time t3) (step S105). The predetermined period Tmd is set as a period during which the correction value Pamd added to the base index Pbase in the vibration suppression mode in step S104 decreases and reaches zero. When the predetermined period Tmd has elapsed since the load was introduced (time t3) (step S105: YES), the correction value Pamd added to the base index Pbase in the vibration suppression mode becomes zero, and the gas turbine control device 50 transitions the operation mode of the gas turbine GT to the normal mode (step S106), completing the series of startup controls. As a result, when the fuel temperature rises and the risk of combustion oscillation decreases, the gas turbine GT can smoothly transition to the normal mode based on the original base index Pbase.

[0059] As described above, according to the above embodiment, it is possible to provide a gas turbine control device, a gas turbine control method, and a gas turbine control program that are capable of suppressing the occurrence of combustion oscillation even when a load is added while the fuel temperature is low.

[0060] In addition, within the scope of the present disclosure, the components in the above-described embodiments may be replaced with well-known components as appropriate, and the above-described embodiments may be combined as appropriate.

[0061] The contents described in each of the above embodiments can be understood, for example, as follows.

[0062] (1) A gas turbine control device according to one aspect includes: A gas turbine control device (50) for controlling a gas turbine (GT) in which a combustor (2) is configured in a form in which a plurality of fuel supply nozzles for supplying fuel are divided into a first group (G1) and a second group (G2), a base index calculation unit (59) for calculating a base index (Pbase) of a control parameter (P) related to a ratio of the fuel supply amount by the second group to the fuel supply amount by the first group based on an operating state of the gas turbine; a correction value calculation unit (56) for calculating a correction value (Pamd) for correcting the base index based on an operating state of the gas turbine; a fuel control unit (51) for controlling the fuel supply amounts of the first group and the second group based on the control parameters obtained by correcting the base index using the correction value; Equipped with The correction value calculation unit calculates the correction value such that the absolute value of the correction value decreases to zero when a predetermined period (Tmd) has elapsed since load incorporation into the gas turbine after the gas turbine is started.

[0063] According to the above aspect (1), fuel supply control of the gas turbine is performed using a control parameter related to the ratio of the fuel supply amounts between the first group and the second group. This control parameter is obtained by correcting a base index calculated based on the operating state using a correction value. This makes it possible to shift the operating state of the gas turbine from a state in which combustion oscillation is likely to occur, ensure control margin even during rapid startup when the fuel temperature is low, and effectively suppress combustion oscillation. This correction value is calculated so that its absolute value decreases to zero after a predetermined period has elapsed since load injection into the gas turbine. This allows a smooth transition to gas turbine control based on the original base index when the fuel temperature rises and the risk of combustion oscillation decreases. As a result, combustion oscillation can be suitably suppressed even when the fuel temperature is low, such as during rapid startup.

[0064] (2) In another embodiment, in the above embodiment (1), The predetermined period is set based on the time (Ti) required to raise the temperature of the fuel and the temperature (Tgt) of the gas turbine at the start-up of the gas turbine.

[0065] According to the above aspect (2), the elapsed time required for the correction value for correcting the base index to decrease to zero is set based on the required time for fuel temperature rise (the time required for low-temperature fuel to rise to the target temperature) and the startup temperature of the gas turbine. As a result, for example, when the fuel temperature is estimated to be low due to a low gas turbine temperature or intake air temperature, the predetermined time is set long, thereby ensuring a long period during which the base index is corrected by the correction value, and thereby making it possible to suitably suppress combustion oscillation.

[0066] (3) In another aspect, in the above aspect (1) or (2), The correction value is calculated based on the intake temperature (T1C) of the gas turbine.

[0067] According to the above aspect (3), the correction value for correcting the base index is calculated based on the intake-air temperature of the gas turbine. As a result, for example, by calculating a larger correction value when the intake-air temperature is low, combustion oscillation that is likely to occur when the fuel temperature is low can be suitably suppressed.

[0068] (4) In another embodiment, in any one of the above (1) to (3), the plurality of fuel supply nozzles include a plurality of main nozzles (252) for supplying fuel to a plurality of main burners arranged at intervals in the circumferential direction, respectively; The plurality of main nozzles are divided into groups A and B, The control parameter is KMB, which is the ratio of the fuel supply amount of the main nozzles of the group B selected as the second group to the fuel supply amount of the main nozzles of the group A selected as the first group.

[0069] According to the above aspect (4), the main nozzles of the combustor are divided into a first group and a second group, and the fuel supply ratio KMB of the first group and the second group is set as the base index. By applying a correction value to such a base index, combustion oscillation can be suitably suppressed.

[0070] (5) In another embodiment, in the above embodiment (4), The correction value is calculated to increase the base index.

[0071] According to the above aspect (5), by correcting the base index to increase, the difference between the size of the flame formed by the main burners belonging to the first group and the size of the flame formed by the main burners belonging to the second group is increased, thereby making it possible to effectively suppress combustion oscillations that tend to occur when the fuel temperature is low.

[0072] (6) In another aspect, in the above aspect (4) or (5), The number of the main nozzles belonging to the first group is different from the number of the main nozzles belonging to the second group.

[0073] According to the above aspect (6), the first group and the second group have different numbers of main nozzles, so that an asymmetric flame is formed in the combustor, making it possible to make combustion oscillation less likely to occur.

[0074] (7) In another embodiment, in any one of the above (1) to (3), The plurality of fuel supply nozzles include: a plurality of main nozzles (252) for supplying fuel to a plurality of main burners arranged at intervals in the circumferential direction, respectively; a plurality of top hat nozzles (253) for supplying fuel to the fuel introduction passages of the plurality of main burners, respectively; Including, The control parameter is a ratio of the fuel supply amount of the plurality of top hat nozzles selected as the second group to the fuel supply amount of the plurality of main nozzles selected as the first group.

[0075] According to the above aspect (7), a plurality of main nozzles included in the combustor are classified into a first group, a plurality of top hat nozzles are classified into a second group, and the fuel supply ratio of both of them is set as a base index. By applying a correction value to such a base index, combustion oscillation can be suitably suppressed.

[0076] (8) In another embodiment, in the above embodiment (7), The correction value is calculated to decrease the base index.

[0077] According to the above aspect (8), when a top hat ratio is used as the base index, the base index is corrected to decrease. For example, when the fuel temperature is low, the correction value is calculated so that the amount of decrease in the base index is large, thereby increasing the fuel supply amount from the multiple main nozzles relative to the fuel supply amount from the top hat nozzle, thereby reducing the differential pressure between the multiple main nozzles and making it possible to suitably suppress the occurrence of combustion oscillation.

[0078] (9) A gas turbine control method according to one aspect includes: A gas turbine control method for controlling a gas turbine (GT) in which a combustor (2) is configured in a form in which a plurality of fuel supply nozzles for supplying fuel are divided into a first group (G1) and a second group (G2), calculating a base index (Pbase) of a control parameter (P) related to a ratio of the fuel supply amount by the second group to the fuel supply amount by the first group based on an operating state of the gas turbine; calculating a correction value (Pamd) for correcting the base index based on an operating state of the gas turbine; controlling the fuel supply amounts of the first group and the second group based on the control parameters obtained by correcting the base index using the correction value; Equipped with In the step of calculating the correction value, the correction value is calculated so that the absolute value of the correction value decreases to zero when a predetermined period (Tmd) has elapsed since load incorporation into the gas turbine after the gas turbine is started.

[0079] According to the above aspect (9), fuel supply control of the gas turbine is performed using a control parameter related to the ratio of the fuel supply amounts between the first group and the second group. This control parameter is obtained by correcting a base index calculated based on the operating state using a correction value. This makes it possible to shift the operating state of the gas turbine from a state in which combustion oscillation is likely to occur, ensure control margin even during rapid startup when the fuel temperature is low, and effectively suppress combustion oscillation. This correction value is calculated so that its absolute value decreases to zero after a predetermined period has elapsed since load injection into the gas turbine. This allows a smooth transition to gas turbine control based on the original base index when the fuel temperature rises and the risk of combustion oscillation decreases. As a result, combustion oscillation can be suitably suppressed even when the fuel temperature is low, such as during rapid startup.

[0080] (10) A gas turbine control program according to one aspect includes: A gas turbine control program for controlling a gas turbine (GT) in which a combustor (2) is configured in a form in which a plurality of fuel supply nozzles for supplying fuel are divided into a first group (G1) and a second group (G2), Using a computer, calculating a base index (Pbase) of a control parameter (P) related to a ratio of the fuel supply amount by the second group to the fuel supply amount by the first group based on an operating state of the gas turbine; calculating a correction value (Pamd) for correcting the base index based on an operating state of the gas turbine; controlling the fuel supply amounts of the first group and the second group based on the control parameters obtained by correcting the base index using the correction value; is executable, In the step of calculating the correction value, after the gas turbine is started, when a predetermined period (Tmd) has elapsed since load incorporation of the gas turbine, the correction value is calculated. Absolute value of The correction value is calculated so that decreases to zero.

[0081] According to the above aspect (10), fuel supply control of the gas turbine is performed using a control parameter related to the ratio of the fuel supply amounts between the first group and the second group. This control parameter is obtained by correcting a base index calculated based on the operating state using a correction value. This makes it possible to shift the operating state of the gas turbine from a state in which combustion oscillation is likely to occur, ensure control margin even during rapid startup when the fuel temperature is low, and effectively suppress combustion oscillation. This correction value is calculated so that its absolute value decreases to zero after a predetermined period has elapsed since load injection into the gas turbine. This allows a smooth transition to gas turbine control based on the original base index when the fuel temperature rises and the risk of combustion oscillation decreases. As a result, combustion oscillation can be suppressed effectively even when the fuel temperature is low, such as during rapid startup. [Explanation of symbols]

[0082] 1 Compressor 2. Combustor 3 Turbine 4 rotors 11 Entrance 12 Compressor casing 13 Compressor stator vane 14 Compressor blade 21 Inner cylinder 22 Tailpiece 23 Outer cylinder 24 Combustor casing 26 Air passage 31 Turbine casing 32 Turbine vane 33 Turbine blade 34 Exhaust chamber 34a Exhaust diffuser 41,42 Bearing section 50 Gas turbine control device 51 Fuel control unit 52 Storage section 53 Pilot fuel supply valve drive unit 59 Base index calculation section 54 Group A main fuel supply valve drive unit 55 B group main fuel supply valve drive unit 56 Correction value calculation unit 57 Top hat fuel supply valve drive unit 60 Gain correction section 62 Counting section 64 Limiter 251 Pilot nozzle 251a fuel port 251b Pilot Fuel Line 251c Pilot fuel supply valve 252 Main nozzle 252a fuel port 252b Main fuel line 252c Main fuel supply valve 252d Swivel Wing 252e Burner tube 253 Top Hat Nozzle 253a fuel port 253b Top Hat Fuel Line 253c Top Hat Fuel Supply Valve G1 1st Group G2 2nd Group GT Gas Turbine P Control parameter Pamd correction value Pamd´ provisional correction value Pamd1 First correction value Pamd2 Second correction value Pamd3 Third correction value Pbase Base Index Ti Heat-up time required T1C Intake temperature Tamd Required temperature rise time correction value Tf fuel temperature Tf0 Target fuel temperature Tgt Gas turbine temperature Tmd predetermined period

Claims

1. A gas turbine control device for controlling a gas turbine having a combustor configured in a form in which a plurality of fuel supply nozzles for supplying fuel are divided into a first group and a second group, the gas turbine control device comprising: a base index calculation unit that calculates a base index of a control parameter related to a ratio of a fuel supply amount by the second group to a fuel supply amount by the first group based on an operating state of the gas turbine; a correction value calculation unit that calculates a correction value for correcting the base index based on an operating state of the gas turbine; a fuel control unit for controlling the fuel supply amounts of the first group and the second group based on the control parameters obtained by correcting the base index using the correction value; Equipped with the correction value calculation unit calculates the correction value such that an absolute value of the correction value decreases to zero when a predetermined period has elapsed since load injection of the gas turbine after the gas turbine has been started, a gas turbine control device, wherein the predetermined period is set based on a time required for the temperature of the fuel to reach a preset target temperature.

2. The gas turbine control device according to claim 1 , wherein the predetermined period is set based on a temperature of the gas turbine at the time of startup of the gas turbine.

3. The gas turbine control device according to claim 1 or 2, wherein the correction value is calculated based on an intake air temperature of the gas turbine.

4. the plurality of fuel supply nozzles include a plurality of main nozzles for supplying fuel to a plurality of main burners arranged at intervals in the circumferential direction, respectively; The plurality of main nozzles are divided into groups A and B, 2. The gas turbine control device according to claim 1, wherein the control parameter is KMB that is a ratio of a fuel supply amount of the main nozzles of the group B selected as the second group to a fuel supply amount of the main nozzles of the group A selected as the first group.

5. The gas turbine control device according to claim 4 , wherein the correction value is calculated to increase the base index.

6. The gas turbine control device according to claim 4 , wherein the number of the main nozzles belonging to the first group is different from the number of the main nozzles belonging to the second group.

7. The plurality of fuel supply nozzles include: a plurality of main nozzles for supplying fuel to a plurality of main burners arranged at intervals in the circumferential direction, respectively; a plurality of top hat nozzles for supplying fuel to fuel introduction passages of the plurality of main burners, respectively; Including, 2. The gas turbine control device according to claim 1, wherein the control parameter is a ratio of a fuel supply amount of the plurality of top hat nozzles selected as the second group to a fuel supply amount of the plurality of main nozzles selected as the first group.

8. The gas turbine control device according to claim 7 , wherein the correction value is calculated to decrease the base index.

9. A gas turbine control method for controlling a gas turbine having a combustor configured in a form in which a plurality of fuel supply nozzles for supplying fuel are divided into a first group and a second group, the method comprising: calculating a base index of a control parameter related to a ratio of the fuel supply amount by the second group to the fuel supply amount by the first group based on an operating state of the gas turbine; calculating a correction value for correcting the base index based on an operating state of the gas turbine; controlling the fuel supply amounts of the first group and the second group based on the control parameters obtained by correcting the base index using the correction value; Equipped with In the step of calculating the correction value, the correction value is calculated such that an absolute value of the correction value decreases to zero when a predetermined period of time has elapsed since load injection of the gas turbine after the gas turbine has been started, and a gas turbine control method, wherein the predetermined period is set based on a time required for a temperature rise of the fuel to reach a preset target temperature;

10. 1. A gas turbine control program for controlling a gas turbine having a combustor configured in a form in which a plurality of fuel injection nozzles for supplying fuel are divided into a first group and a second group, the program comprising: Using a computer, calculating a base index of a control parameter related to a ratio of the fuel supply amount by the second group to the fuel supply amount by the first group based on an operating state of the gas turbine; calculating a correction value for correcting the base index based on an operating state of the gas turbine; controlling the fuel supply amounts of the first group and the second group based on the control parameters obtained by correcting the base index using the correction value; is executable, In the step of calculating the correction value, the correction value is calculated such that an absolute value of the correction value decreases to zero when a predetermined period of time has elapsed since load injection of the gas turbine after the gas turbine has been started, and the predetermined period is set based on a time required for the temperature of the fuel to reach a preset target temperature.

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