Gas turbine control device, and gas turbine control method

Abstract

To reduce an overshoot of an exhaust gas temperature even if a load increase speed is high.SOLUTION: A gas turbine control device calculates a fuel flow rate command for controlling a supply flow rate of fuel to a gas turbine on the basis of an exhaust gas temperature and a deviation from a reference exhaust gas temperature. The reference exhaust gas temperature is adjusted by a bias value. The bias value for adjusting the reference exhaust gas temperature corresponding to the exhaust gas temperature is calculated on the basis of a load increase speed of the gas turbine.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a gas turbine control device and a gas turbine control method. [Background technology]

[0002] In thermal power plants and the like, gas turbines capable of outputting power by driving a turbine with combustion gas generated by burning fuel are used as a power source for driving a generator. When starting up a gas turbine, the turbine speed is increased to a predetermined target speed (e.g., rated speed), and then a load is applied. The magnitude of the load on the gas turbine is controlled so as to gradually increase. During such load increase, exhaust gas temperature control is performed so that the turbine inlet temperature of the gas turbine does not exceed a preset upper limit. Exhaust gas temperature control is performed, for example, by adjusting the fuel flow rate so that the actual value of the exhaust gas temperature measured by a sensor or the like does not exceed a preset upper limit.

[0003] In exhaust gas temperature control, the fuel flow rate is adjusted by a fuel flow rate command calculated based on the difference between the actual exhaust gas temperature measurement value and the upper limit value. However, due to delays in the response of sensors such as thermocouples for measuring exhaust gas temperature and controllers, this difference may become large, causing the fuel flow rate to temporarily become excessive, resulting in an overshoot in the turbine inlet temperature. An overshoot in the turbine inlet temperature can be a factor that causes combustion oscillations and other problems in the gas turbine.

[0004] For example, Patent Document 1 discloses a technique for preventing an overshoot of the turbine inlet temperature during such a load increase. In this document, exhaust gas temperature is controlled by comparing the temperature downstream of the turbine blades (blade path temperature) with a blade path temperature set value, which is a reference value. This blade path temperature set value is found by adding a bias value to a reference value corresponding to the exhaust gas temperature further downstream than the blade path temperature, and it is proposed to gradually decrease this bias value when the load of the gas turbine increases and reaches or exceeds a specified load, and then gradually increase it back to the original value to suppress the overshoot. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2002-221048 A Summary of the Invention [Problem to be solved by the invention]

[0006] The measurement sensitivity of the exhaust gas temperature by the sensor during a load increase of the gas turbine depends on the load increase rate. For example, when the load increase rate of the gas turbine is high, such as during a rapid start-up or a sudden increase in the target load, the exhaust gas temperature measured by the sensor tends to be lower than when the load increase rate is low. Therefore, when a fuel flow command during a load increase is calculated based on the difference between the exhaust gas temperature and a predetermined reference temperature, the difference becomes temporarily excessive, which makes it easy for an overshoot to occur in the turbine inlet temperature. In the above-mentioned Patent Document 1, an overshoot is suppressed by adjusting a bias value for calculating a blade path temperature setpoint when the gas turbine load becomes equal to or exceeds a specified load, but the influence of such a load increase rate is not taken into consideration.

[0007] At least one embodiment of the present disclosure has been made in consideration of the above-described circumstances, and an object of the present disclosure is to provide a gas turbine control device and a gas turbine control method that are capable of reducing an overshoot in exhaust gas temperature even when the load increase rate is high. [Means for solving the problem]

[0008] In order to solve the above problems, a gas turbine control device according to at least one embodiment of the present disclosure includes: a load increase rate detection unit for detecting a load increase rate of the gas turbine; an exhaust gas temperature detection unit for detecting an exhaust gas temperature of the gas turbine; a bias value calculation unit for calculating a bias value for adjusting a reference exhaust gas temperature corresponding to the exhaust gas temperature based on the load increase rate; a fuel flow rate command calculation unit that calculates a fuel flow rate command for controlling a supply flow rate of fuel to the gas turbine, based on a deviation between the exhaust gas temperature and the reference exhaust gas temperature adjusted by the bias value; Equipped with.

[0009] In order to solve the above problem, a gas turbine control method according to at least one embodiment of the present disclosure includes: detecting a load ramp rate of the gas turbine; detecting an exhaust gas temperature of the gas turbine; calculating a bias value for adjusting a reference temperature corresponding to the exhaust gas temperature based on the load increase rate; calculating a fuel flow rate command for controlling a supply flow rate of fuel to the gas turbine based on a deviation between the exhaust gas temperature and the reference temperature adjusted by the bias value; Equipped with. Effect of the Invention

[0010] According to at least one embodiment of the present disclosure, it is possible to provide a gas turbine control device and a gas turbine control method that are capable of reducing an overshoot in exhaust gas temperature even when the load increase rate is high. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram illustrating a schematic configuration of a gas turbine according to an embodiment. [Diagram 2] FIG. 2 is a block diagram showing a functional configuration of a gas turbine control device according to an embodiment. [Diagram 3] 4 is a graph showing a change in load of a gas turbine over time when the load increases. [Figure 4] 4 is a control flow diagram of a reference temperature calculation unit and a bias value calculation unit in FIG. 3. [Diagram 5] 5 is an example of the first function in FIG. [Figure 6] 5 is an example of the second function in FIG. 4. [Figure 7] 5 is an example of the third function in FIG. [Figure 8] 5 is an example of the fourth function in FIG. [Figure 9A] 10 is a time chart showing a change in blade path temperature with respect to a load change of a gas turbine when the load increase rate is relatively small, together with a reference blade path temperature. [Figure 9B] 10 is a time chart showing a change in blade path temperature with respect to a load change of a gas turbine when the load increase rate is relatively high, together with a reference blade path temperature. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, some embodiments will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of 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 invention.

[0013] First, a gas turbine 1 that is a control target of a gas turbine control device 100 according to at least one embodiment of the present disclosure will be described with reference to Fig. 1. Fig. 1 is a diagram showing a schematic configuration of a gas turbine 1 according to one embodiment.

[0014] The gas turbine 1 includes a compressor 3 for generating compressed air (hereinafter, appropriately referred to as "combustion air A"); a combustor 2 for generating combustion gas Gc by mixing and burning the combustion air A generated by the compressor 3 with a fuel F; a fuel supply system 4 for supplying the fuel F to the combustor 2; and a turbine 6 that can be driven by the combustion gas Gc. The compressor 3 and the turbine 6 are connected to one shaft. In the gas turbine 1 having such a configuration, the combustion air A is supplied from the compressor 3 to the combustor 2, and the fuel F is supplied from the fuel supply system 4, and these are mixed and burned to generate the combustion gas Gc. This combustion gas Gc flows into the turbine 6 and becomes a working medium for driving the turbine 6. In addition, a generator 7 is connected to the output shaft of the turbine 6. As a result, the generator 7 is driven by the power output from the turbine 6, and electric energy can be obtained. Incidentally, the combustion gas Gc that has completed its work in the turbine 6 is discharged to the outside via an exhaust gas line 16 as exhaust gas Gex.

[0015] The fuel supply system 4 uses, for example, liquefied natural gas (LNG) as the fuel F to be supplied to the combustor 2. The fuel F may be mixed with hydrogen gas, which has a higher combustion speed than natural gas. The fuel supply system 4 has a fuel supply line 4a that connects a fuel supply source and the combustor 2. A fuel flow rate control valve, a shutoff valve, a flow meter, and the like (not shown) are disposed in the fuel supply line 4a. Each component provided in the fuel supply line 4a is controlled based on a control signal from a gas turbine control device 100 (described later), thereby making it possible to adjust the amount of fuel supplied by the fuel supply system 4.

[0016] The compressor 2 also includes an inlet guide vane (IGV) 8. The opening degree of the inlet guide vane 8 is variably controlled by a gas turbine control device 100 described later, so that the flow rate of the combustion air A supplied to the combustor 2 can be adjusted.

[0017] A part of the compressed air generated by the compressor 2 can be supplied to the casing of the turbine 6 as cooling air Ac. The cooling air Ac generated by the compressor 2 is led to a cooling air flow path (not shown) formed in the casing of the turbine 6 via a cooling air supply line 10. The cooling air flow path is capable of exchanging heat with the main body of the turbine 6, and cools the turbine 6 by heat exchange with the cooling air Ac flowing through the cooling air flow path. The cooling air supply line 10 is provided with a cooling air adjustment valve 12 for adjusting the opening degree of the cooling air adjustment valve to adjust the flow rate of the cooling air Ac. After cooling the turbine 6, the cooling air Ac is discharged to the outside via a cooling air discharge line 14.

[0018] A blade path temperature sensor 17 is provided on the downstream side of the blades in the turbine 6 to detect the temperature at that position (a position downstream of the blades including the moving blades and the stationary blades of the turbine 6) (hereinafter, appropriately referred to as the "blade path temperature BPT"). Also, an exhaust gas temperature sensor 18 is provided in the exhaust gas line 16 to detect the temperature of the exhaust gas Gex (hereinafter, appropriately referred to as the "exhaust gas temperature EXT").

[0019] Next, a gas turbine control device 100 for controlling the gas turbine 1 having the above configuration will be described. The gas turbine control device 100 is a control unit for controlling the gas turbine 1, and is composed of, for example, a central processing unit (CPU), a random access memory (RAM), a read only memory (ROM), and a computer-readable storage medium. A series of processes for realizing various functions is stored in a storage medium or the like in the form of a program, for example, and the CPU reads the program into the RAM or the like and executes information processing and arithmetic processing to realize various functions. The program may be installed in a ROM or other storage medium in advance, may be provided in a state stored in a computer-readable storage medium, or may be distributed via a wired or wireless communication means. The computer-readable storage medium is, for example, a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, or a semiconductor memory.

[0020] 2 is a block diagram showing a functional configuration of a gas turbine control device 100 according to an embodiment. The gas turbine control device 100 includes an operating state acquisition unit 110, a load increase rate detection unit 120, a reference temperature calculation unit 130, a bias value calculation unit 140, a first fuel flow rate command calculation unit 150, a second fuel flow rate command calculation unit 160, and a control unit 170.

[0021] The operating state acquisition unit 110 is configured to acquire various information related to the operating state of the gas turbine 1. In this embodiment, the operating state acquisition unit 110 acquires, as information related to the operating state of the gas turbine 1, at least a load L of the gas turbine, a blade path temperature BPT, an exhaust gas temperature EXT, a casing pressure Ps, an atmospheric pressure Pa, and an opening degree D of the cooling air regulating valve 12.

[0022] In this embodiment, the blade path temperature BPT can be obtained as an actual measurement value by the above-mentioned blade path temperature sensor 17, but it may be an estimated value calculated based on the exhaust gas temperature EXT. In this case, since the blade path temperature BPT is a temperature upstream of the exhaust gas temperature EXT, it may be estimated by adding a predetermined bias value to the exhaust gas temperature EXT.

[0023] The load increase speed detection unit 120 is configured to detect a load increase speed LIR of the gas turbine 1. The load increase speed detection unit 120 calculates the load increase speed LIR based on a change amount ΔL of the load L in a predetermined period Δt. More specifically, the load increase speed detection unit 120 can obtain the load increase speed LIR based on a time required for the load L of the gas turbine 1 to increase from a first reference load L1 to a second reference load L2 during a load increase.

[0024] FIG. 3 is a graph showing a time change of the load L of the gas turbine 1 during a load increase. FIG. 3 shows a behavior in which, at the start of the gas turbine 1, after the rotation speed of the gas turbine 1 reaches the rated rotation speed, an initial load L0 is input at time t0, and then the load L of the gas turbine 1 increases to the rated load (100%) at time t3. In this example, the first reference load L1 is set to about 5%, and the second reference load L2 is set to about 95%. The load L, which starts to increase at time t0, reaches the first reference load L1 at time t1, and reaches the second reference load L2 at time t2 (>t1). In this case, the load increase speed detection unit 120 can calculate the load increase speed LIR by dividing the change amount ΔL (=L2-L1) of the load L by a predetermined period Δt (=t2-t1).

[0025] In addition, when the gas turbine is controlled based on an external load increase command, the timing of receiving the load increase command may be regarded as the time t1 when the gas turbine load L reaches the first reference load L1. In addition, when the opening degree of the inlet guide vane 8 is gradually increased in accordance with an increase in the load of the gas turbine, the timing when the opening degree of the inlet guide vane 8 reaches the rated opening degree may be regarded as the time t2 when the gas turbine load L reaches the second reference load L2.

[0026] The reference temperature calculation unit 130 is configured to calculate reference temperatures corresponding to various temperatures used as control parameters when controlling the gas turbine 1. In this embodiment, the blade pass temperature BPT at the rear stage of the turbine and the exhaust gas temperature EXT downstream of the blade pass temperature BPT are each used as the control parameters (the blade pass temperature BPT and the exhaust gas temperature EXT are both exhaust gas temperatures in a broad sense). Therefore, the reference temperature calculation unit 130 calculates, as the reference temperatures, a reference blade pass temperature BPTref corresponding to the blade pass temperature BPT and a reference exhaust gas temperature EXTref corresponding to the exhaust gas temperature EXT.

[0027] The bias value calculation unit 140 is configured to calculate a bias value for adjusting the reference temperature calculated by the reference temperature calculation unit 130. In this embodiment, the bias value calculation unit 140 calculates a bias value ΔBPT for adjusting a reference blade path temperature BPTref corresponding to the blade path temperature BPT among the reference temperatures calculated by the reference temperature calculation unit 130.

[0028] The first fuel flow rate command calculation unit 150 is configured to calculate the first fuel flow rate command BPCSO based on the blade path temperature BPT. A specific calculation method of the first fuel flow rate command BPCSO by the first fuel flow rate command calculation unit 150 will be described later with reference to Fig. 4, and is performed by PI control based on the deviation ΔBPT between the blade path temperature BPT included in the information on the operating state acquired by the operating state acquisition unit 110 and the reference blade path temperature BPTref calculated by the reference temperature calculation unit 130.

[0029] The second fuel flow rate command calculation unit 160 is configured to calculate the second fuel flow rate command EXCSO based on the exhaust gas temperature EXT. A specific calculation method of the second fuel flow rate command EXCSO by the second fuel flow rate command calculation unit 160 will be described later with reference to Fig. 4, and is performed by PI control based on the deviation ΔEXT between the exhaust gas temperature EXT included in the information on the operating state acquired by the operating state acquisition unit 110 and the reference exhaust gas temperature EXTref calculated by the reference temperature calculation unit 130.

[0030] The control unit 170 is configured to control the fuel supply system 4 using either the first fuel flow rate command BPCSO calculated by the first fuel flow rate command calculation unit 150 or the second fuel flow rate command calculation unit 160 as a fuel flow rate command. For example, the control unit 170 may execute a first control mode in which the fuel supply system is controlled using the first fuel flow rate command BPCSO as a fuel flow rate command, and then may shift to a second control mode in which the fuel supply system is controlled using the second fuel flow rate command EXCSO as a fuel flow rate command, on condition that a predetermined condition is satisfied. In this case, a predetermined bias value may be added to at least one of the first fuel flow rate command BPCSO or the second fuel flow rate command EXCSO to select a lower value, thereby automatically shifting from the first control mode to the second control mode when the predetermined condition is satisfied.

[0031] Next, a detailed description will be given of the control flow in the reference temperature calculation unit 130 and the bias value calculation unit 140. Fig. 4 is a control flow diagram in the reference temperature calculation unit 130 and the bias value calculation unit 140 of Fig. 3.

[0032] The reference temperature calculation unit 130 calculates the cabin pressure ratio Rp based on the cabin pressure Ps and the atmospheric pressure Pa among the information related to the operating state acquired by the operating state acquisition unit 110. This cabin pressure ratio Rp is input to a first function FX1, whereby a corresponding reference exhaust gas temperature EXTref is calculated. The first function FX1 is a function that defines the correlation between the cabin pressure ratio Rp and the reference exhaust gas temperature EXTref, and is prepared in advance by an experimental, theoretical, or simulation method. FIG. 5 is an example of the first function FX1 of FIG. 4. In this example, the first function FX1 is defined so that the reference exhaust gas temperature EXTref decreases as the cabin pressure ratio Rp increases (particularly, the first function FX1 is defined so that the rate of decrease of the reference exhaust gas temperature EXTref decreases as the cabin pressure ratio Rp increases).

[0033] Furthermore, the cabin pressure ratio Rp is input into a second function FX2 to calculate the corresponding uncorrected reference blade pass temperature BPTref (hereinafter referred to as "reference blade pass temperature basic value BPTref'" where appropriate). The second function FX2 is a function that defines the correlation between the cabin pressure ratio Rp and the reference blade pass temperature basic value BPTref', and is prepared in advance by an experimental, theoretical or simulation method. Figure 6 is an example of the second function FX2 of Figure 4. In this example, the second function FX2 is defined so that the reference blade pass temperature basic value BPTref' decreases as the cabin pressure ratio Rp increases (in particular, the second function FX2 is defined so that the rate of decrease of the reference exhaust gas temperature EXTref increases as the cabin pressure ratio Rp increases).

[0034] The reference blade path temperature basic value BPTref' is corrected by subtracting the bias value ΔBPTref calculated by the bias value calculation unit 140 to obtain the reference blade path temperature BPTref. The reference blade path temperature BPTref is input to the above-mentioned first fuel flow rate command calculation unit 150. In the first fuel flow rate command calculation unit 150, the deviation between the blade path temperature BPT, which is included in the information relating to the operating state acquired by the operating state acquisition unit 110, and the reference blade path temperature BPTref is input to a PI controller 152, and a first fuel flow rate command calculation BPCSO corresponding to the deviation is calculated.

[0035] Further, the reference exhaust gas temperature EXTref is input to the above-mentioned second fuel flow rate command calculation unit 160. In the second fuel flow rate command calculation unit 160, the deviation between the exhaust gas temperature EXT and the reference exhaust gas temperature EXTref, which is included in the information relating to the operating state acquired by the operating state acquisition unit 110, is input to a PI controller 162, and the second fuel flow rate command calculation EXCSO corresponding to the deviation is calculated.

[0036] In the bias value calculation unit 140, the load increase speed LIR obtained by the load increase speed detection unit 120 is input to the third function FX3, and the corresponding first bias value ΔBPT1 is calculated. The third function FX3 is a function that defines the correlation between the load increase speed LIR and the first bias value ΔBPT1, and is prepared in advance by an experimental, theoretical, or simulation method. FIG. 7 is an example of the third function FX3 in FIG. 4. In this example, the third function FX3 is defined so that the first bias value ΔBPT1 increases as the load increase speed LIR increases. In particular, when the load increase speed LIR is less than the first value LIR1 and is equal to or greater than the second value LIR2, the first bias value ΔBPT1 is approximately constant, and when the load increase speed LIR is equal to or greater than the first value LIR1 and less than the second value LIR2, the first bias value ΔBPT1 increases in proportion to the load increase speed LIR.

[0037] In addition, in the bias value calculation unit 140, the deviation DFR between the opening degree D of the cooling air regulating valve 12 and the planned value Dref corresponding to the opening degree D, among the information on the operating state acquired by the operating state acquisition unit 110, is input to a fourth function FX4, whereby the corresponding second bias value ΔBPT2 is calculated. The fourth function FX4 is a function that defines the correlation between the deviation DFR and the second bias value ΔBPT2, and is prepared in advance by an experimental, theoretical, or simulation method. FIG. 8 is an example of the fourth function FX4 of FIG. 4. In this example, the fourth function FX4 is defined so that the absolute value of the second bias value ΔBPT2 increases as the deviation DFR increases. In particular, when the deviation DFR is less than the first value DFR1 and is equal to or greater than the second value DFR2, the second bias value ΔBPT2 is approximately constant, and when the deviation ΔD is equal to or greater than the first value ΔD1 and less than the second value ΔD2, the second bias value ΔBPT2 decreases inversely proportional to the deviation ΔD.

[0038] The first bias value ΔBPT1 and the second bias value ΔBPT2 calculated in this manner are added together to determine the bypass value ΔBPT. The switching unit SW outputs either the bias value ΔBPT or a fixed value "0" depending on whether the switching signal SS is ON or OFF. Specifically, when the switching signal SS is ON, the switching unit SW outputs the bias value ΔBPT to correct the reference blade path temperature basic value BPTref' by subtracting the bias value ΔBPT from the reference blade path temperature basic value BPTref'. On the other hand, when the switching signal SS is OFF, the switching unit SW outputs the fixed value "0". In this case, the reference blade path temperature BPTref is the reference blade path temperature basic value BPTref' itself.

[0039] The switching signal SS is switched from OFF to ON when the load L reaches a predetermined value (e.g., 95%) during load increase of the gas turbine 1. Such ON / OFF of the switching signal SS may be performed directly based on the load L, or may be performed based on other control parameters related to the load L. In this embodiment, the switching signal SS is turned ON / OFF based on the opening of the inlet guide vane 8 which is controlled in conjunction with the load L (for example, in a case where the opening of the inlet guide vane 8 is controlled to increase together with the load L, when it is determined that the load L has reached a predetermined value (e.g., 95%) based on the reaching of the rated opening D (e.g., 100%), the switching signal SS is switched from OFF to ON).

[0040] Next, the operation of the gas turbine 1 having the above configuration will be specifically described. Figures 9A and 9B are time charts showing the change in the blade pass temperature BPT relative to the load change of the gas turbine 1, together with the reference blade pass temperature BPTref.

[0041] 9A shows the change in the blade path temperature BPT when the load increase rate LIR of the gas turbine 1 is relatively small. In this case, an overshoot occurs in the blade path temperature BPT when the load L reaches the rated load (100%), but the magnitude of the overshoot is relatively small.

[0042] On the other hand, Fig. 9B shows a change in the blade pass temperature BPT when the load increase rate LIR of the gas turbine 1 is large compared to Fig. 9A. In this case, the measured value of the blade pass temperature BPT by the blade pass temperature sensor 17 tends to be lower compared to the case where the load increase rate LIR is low as in Fig. 9A. Therefore, in the case where the first fuel flow rate command calculation unit 150 calculates the first fuel flow rate command BPCSO at the time of load increase based on the difference between the blade pass temperature BPT and the reference blade pass temperature BPTref, if the reference blade pass temperature basic value BPTref' (reference blade pass temperature not corrected by the bias value ΔBPT) is set as the reference blade pass temperature BPTref, as shown in Fig. 9B, the first fuel flow rate command BPCSO temporarily increases, causing a large overshoot in the blade pass temperature BPT.

[0043] In contrast, in this embodiment, the reference blade path temperature BPTref is calculated by subtracting the bias value ΔBPT calculated based on the load rise speed LIR from the reference blade path temperature basic value BPTref'. When the load rise speed LIR is high, as described above with reference to Fig. 7, the first bias value ΔBPT1 output from the third function FX3 becomes large corresponding to the load rise speed LIR, and the bias value ΔBPT becomes large. As a result, when the load rise speed LIR is high, a temporary increase in the first fuel flow rate command BPCSO is suppressed, and overshoot can be reduced.

[0044] 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.

[0045] The contents described in each of the above embodiments can be understood, for example, as follows.

[0046] (1) A gas turbine control device according to one aspect includes: a load increase rate detection unit for detecting a load increase rate of the gas turbine; an exhaust gas temperature detection unit for detecting an exhaust gas temperature of the gas turbine; a bias value calculation unit for calculating a bias value for adjusting a reference exhaust gas temperature corresponding to the exhaust gas temperature based on the load increase rate; a fuel flow rate command calculation unit that calculates a fuel flow rate command for controlling a supply flow rate of fuel to the gas turbine, based on a deviation between the exhaust gas temperature and the reference exhaust gas temperature adjusted by the bias value; Equipped with.

[0047] According to the above aspect (1), the fuel supply flow rate control for the gas turbine is performed using a fuel flow rate command calculated based on the deviation between the detected value of the exhaust gas temperature and the reference exhaust gas temperature. The reference exhaust gas temperature is adjusted by a bias value calculated based on the load increase rate, thereby preventing the fuel supply command from becoming temporarily excessive when the load increases. This makes it possible to effectively prevent the turbine inlet temperature from overshooting when the load increases, even when the load increase rate is high.

[0048] (2) In another embodiment, in the above embodiment (1), The bias value calculation unit calculates the bias value to be larger as the load increase speed increases.

[0049] According to the above aspect (2), the bias value for adjusting the standard exhaust gas temperature is calculated to be larger as the load increase rate increases. This increases the adjustment amount of the standard exhaust gas temperature when the load increase rate increases, so that it is possible to effectively suppress overshooting of the turbine inlet temperature during load increase even when the load increase rate is high.

[0050] (3) In another embodiment, in the above embodiment (2), If the load rise rate is less than a threshold value, the bias value remains constant regardless of the load rise rate.

[0051] According to the above aspect (3), when the load increase rate is sufficiently slow because it is smaller than the threshold value, the bias value for adjusting the standard exhaust gas temperature is maintained constant regardless of the load increase rate. As a result, when the load increase is sufficiently gradual, the adjustment amount of the standard exhaust gas temperature is reduced, enabling stable operation control of the gas turbine.

[0052] (4) In another embodiment, in any one of the above (1) to (3), The load increase rate detection unit detects the load increase rate based on a time required for the load of the gas turbine to increase from a first reference load to a second reference load that is larger than the first reference load.

[0053] According to the above aspect (4), the load increase speed can be quantitatively detected based on the time required for the load of the gas turbine to increase from the first reference load to the second reference load.

[0054] (5) In another embodiment, in the above embodiment (4), After the load of the gas turbine reaches the second reference load, the absolute value of the bias value gradually decreases.

[0055] According to the above aspect (5), after the load of the gas turbine reaches the second standard load, the bias value for adjusting the standard exhaust gas temperature is controlled to gradually decrease. As a result, when a sufficient amount of time has passed after the load increase is completed, the adjustment amount of the standard exhaust gas temperature by the bias value decreases, so that the standard exhaust gas temperature can be smoothly returned to the original standard exhaust gas temperature (the standard exhaust gas temperature before adjustment) suitable for normal gas turbine control.

[0056] (6) In another embodiment, in any one of the above (1) to (5), The bias value calculation unit calculates the bias value based on an opening degree of a cooling air regulating valve of the gas turbine.

[0057] According to the above aspect (6), the bias value for adjusting the standard exhaust gas temperature is calculated taking into consideration the opening degree of the cooling air regulating valve in addition to the load increase rate described above. This makes it possible to adjust the standard exhaust gas temperature taking into consideration the effect on the cooling air supplied to the gas turbine, and more suitably suppresses the overshoot of the turbine inlet temperature when the load increases.

[0058] (7) In another embodiment, in the above embodiment (6), As the opening degree of the cooling air regulating valve increases, the absolute value of the bias value increases.

[0059] According to the above aspect (7), as the opening of the cooling air regulating valve increases and the amount of cooling air supplied to the gas turbine increases, the absolute value of the bias value increases. This reduces the amount of adjustment of the reference exhaust gas temperature by the bias value, making it possible to suitably suppress overshooting of the turbine inlet temperature when the load increases.

[0060] (8) In another embodiment, in any one of the above (1) to (7), The reference exhaust gas temperature is set based on a pressure ratio of a casing pressure of the gas turbine to an atmospheric pressure.

[0061] According to the above aspect (8), the reference exhaust gas temperature that is the target of adjustment by the bias value can be suitably set based on the pressure ratio of the casing pressure of the gas turbine to the atmospheric pressure.

[0062] (9) In another embodiment, in any one of the above (1) to (8), The gas turbine further includes an opening control unit for controlling an opening of a fuel flow valve provided in a fuel supply system of the gas turbine based on the fuel flow command.

[0063] According to the above aspect (9), the fuel flow rate through the fuel supply system is controlled based on the fuel flow rate command calculated as described above. This makes it possible to suitably suppress overshooting that occurs in the turbine inlet temperature during load increase, even if the load increase rate is high.

[0064] (10) A gas turbine control method according to one aspect includes the steps of: detecting a load ramp rate of the gas turbine; detecting an exhaust gas temperature of the gas turbine; calculating a bias value for adjusting a reference temperature corresponding to the exhaust gas temperature based on the load increase rate; calculating a fuel flow rate command for controlling a supply flow rate of fuel to the gas turbine based on a deviation between the exhaust gas temperature and the reference temperature adjusted by the bias value; Equipped with.

[0065] According to the above aspect (10), the fuel supply flow rate control for the gas turbine is performed using a fuel flow rate command calculated based on the deviation between the detected value of the exhaust gas temperature and the reference exhaust gas temperature. The reference exhaust gas temperature is adjusted by a bias value calculated based on the load increase rate, thereby preventing the fuel supply command from becoming temporarily excessive when the load increases. This makes it possible to effectively prevent the turbine inlet temperature from overshooting when the load increases, even when the load increase rate is high. [Explanation of symbols]

[0066] 1. Gas turbine 2. Combustor 3. Compressor 4 Fuel supply system 4a Fuel supply line 6. Turbine 8 Inlet guide vane 10 Cooling air supply line 12 Cooling air Cooling air regulating valve 14 Cooling air exhaust line 16 Exhaust gas line 17 Blade Path Temperature Sensor 18 Exhaust gas temperature sensor 100 Gas turbine control device 110 Operation status acquisition unit 120 Load rise speed detector 130 Reference temperature calculation section 140 Bias value calculation unit 150 1st fuel flow rate command calculation section 160 2nd fuel flow rate command calculation section 170 Control section

Claims

1. a load increase rate detection unit for detecting a load increase rate of the gas turbine; an exhaust gas temperature detection unit for detecting an exhaust gas temperature of the gas turbine; a bias value calculation unit for calculating a bias value for adjusting a reference exhaust gas temperature corresponding to the exhaust gas temperature based on the load increase rate; a fuel flow rate command calculation unit that calculates a fuel flow rate command for controlling a supply flow rate of fuel to the gas turbine, based on a deviation between the exhaust gas temperature and the reference exhaust gas temperature adjusted by the bias value; A gas turbine control device comprising:

2. The gas turbine control device according to claim 1 , wherein the bias value calculation unit calculates the bias value to be larger as the load increase rate increases.

3. The gas turbine control device of claim 2 , wherein the bias value is maintained constant regardless of the load rise rate if the load rise rate is less than a threshold value.

4. 3. The gas turbine control device according to claim 1, wherein the load increase rate detection unit detects the load increase rate based on a time required for a load of the gas turbine to increase from a first reference load to a second reference load that is larger than the first reference load.

5. The gas turbine control device according to claim 4 , wherein an absolute value of the bias value gradually increases after a load of the gas turbine reaches the second reference load.

6. 3. The gas turbine control device according to claim 1, wherein the bias value calculation unit calculates the bias value based on an opening degree of a cooling air regulating valve of the gas turbine.

7. The gas turbine control device according to claim 6 , wherein an absolute value of the bias value increases as an opening degree of the cooling air regulating valve increases.

8. 3. The gas turbine control device according to claim 1, wherein the reference exhaust gas temperature is set based on a pressure ratio of a casing pressure of the gas turbine to an atmospheric pressure.

9. 3. The gas turbine control device according to claim 1, further comprising an opening control unit for controlling an opening of a fuel flow valve provided in a fuel supply system of the gas turbine based on the fuel flow command.

10. detecting a load ramp rate of the gas turbine; detecting an exhaust gas temperature of the gas turbine; calculating a bias value for adjusting a reference temperature corresponding to the exhaust gas temperature based on the load increase rate; calculating a fuel flow rate command for controlling a supply flow rate of fuel to the gas turbine based on a deviation between the exhaust gas temperature and the reference temperature adjusted by the bias value; A gas turbine control method comprising:

Images