JPH10317991A - Gas turbine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the amount of NOx while stabilizing the combustion of a combustor in a gas turbine at a load increase or decrease in the turbine, which combustor has combustion liners each provided with a plurality of premix burners and fuel lines, by controlling the fuel-air ratio according to the combustion states of the burners. SOLUTION: The combustion states of premix burners in a gas turbine combustor are detected on the basis of the flame stabilizer metal temperature, combustor liner metal temperature and combustor gas temperature, and the fuel lines of the burners corresponding to the detected positions are accordingly controlled so that the burner combustion is stabilized according to partial misfires therein and the fuel flow rate deviation. That control, prevents a rise in quantity of NOx, ensures a stable combustion tolerance and protects the gas turbine effectively, while stabilizing the combustion at a load increase or decrease in the gas turbine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas turbine, and more particularly, to a gas turbine that performs diffusion combustion and premix combustion using a plurality of fuel control systems.

[0002]

2. Description of the Related Art For example, low NO described in Japanese Patent Application No. 6-70416 is disclosed.
The x combustor has one diffusion combustion burner in the central portion on the upstream side of the combustion chamber, and has an annular premixed combustion burner around it. The premixed combustion burner is divided in the circumferential direction to form a plurality of premixed combustion burners. A mixed combustion burner is formed, and a plurality of fuel supply systems for supplying fuel to each burner are provided, and the number of premixed combustion burners operated according to the load of the gas turbine is controlled.

Japanese Patent Laid-Open Publication No. 5-195822 describes that the number of fuel nozzles for supplying fuel is controlled in accordance with the load.

[0004]

However, when operating a gas turbine provided with a plurality of premix burners provided with fuel supply control means, the premix combustion portion is connected to one premix burner in the gas turbine combustor. There is no description on control in the event of abnormal combustion. Proper operation control in such a case is important for improving the operability of the gas turbine.

Accordingly, an object of the present invention is to provide a gas turbine capable of improving operability.

[0006]

A first feature of the present invention is as follows.
A diffusion burner section for performing diffusion combustion, and a premix burner section for premix combustion of a premixed gas of fuel and air on an outer peripheral side of the diffusion burner section, wherein the premix burner section controls a fuel amount of the premixed gas. A plurality of premix burners having control means for controlling are arranged in the circumferential direction, and a plurality of gas turbine combustors including a combustion liner for burning fuel supplied from the diffusion burner section and the premix burner section are provided, In a gas turbine including a turbine driven by combustion gas supplied from the plurality of gas turbine combustors, the gas turbine includes a detection unit for detecting an abnormality in a combustion state of each of the premix burners, and a signal from the detection unit is communicated, Based on the signal, the misfire state of the premix burner is detected, and the flow rate of fuel supplied to the premix burner in the detected misfire state is increased to ensure combustion and continue. Those having a control unit which controls to rolling.

Thus, even if a combustion abnormality such as misfire occurs in one premixed burner in the gas turbine combustor, the premixed burner can be brought into a state in which the premixed burner is more easily combusted, and can be easily performed. Can reignite. This allows
The operability of the gas turbine can be improved.

A second feature of the present invention is that a diffusion burner section for performing diffusion combustion and a premix burner section for premixing combustion of a premixed air of fuel and air on the outer peripheral side of the diffusion burner section are provided. A plurality of mother fuel supply systems provided with control means for controlling the amount of fuel for supplying fuel to the premix burner, and a plurality of gas turbine combustors branched from the mother fuel supply system; A plurality of fuel supply paths each including a plurality of fuel supply systems for supplying fuel to the premix burner are provided in correspondence with the premix burners provided in the gas turbine combustor, and the diffusion burner section and the premix burner section each include a fuel supply path. A plurality of gas turbine combustors each including a combustion liner for burning supplied fuel; and a gas turbine including a turbine driven by combustion gas supplied from the plurality of gas turbine combustors. There are, said each base fuel supply system calculates the average value of the combustion temperature of the premixed burner, reduces the amount of fuel supplied to the premix burner of the system the average value is maximum,
A control device is provided for controlling so as to increase the fuel supply amount to the premix burner of the system having the minimum average value.

Thus, the combustion state of the plurality of premixed combustion burners is detected, and the fuel flow rate of each burner is adjusted according to the combustion state, so that the fuel-air ratio of each burner can be controlled uniformly. As a result, it is possible to prevent NOx from rising and secure a stable combustion margin. Further, the protection of the gas turbine such as a load drop due to the detection of a burner misfire or the like can be performed well.

Since the metal temperature of the flame stabilizer of each premix burner changes depending on the temperature of the flame formed downstream of the flame stabilizer, the combustion of each burner is detected by detecting the metal temperature of the flame stabilizer. It is possible to judge the state, that is, the ignition misfire of each burner, and to estimate the fuel-air ratio of each burner.

Further, since the metal temperature of the combustor liner also changes according to the combustion gas temperature of the corresponding burner, it is possible to determine the combustion state of each burner.

Further, since the temperature of the combustion gas near the wall of the combustor liner is difficult to directly measure because the temperature of the combustion gas of each premixed combustion burner is extremely high, it is cooled by cooling air of the combustor liner. The combustion state of each burner can be determined by measuring the gas temperature near the combustor liner wall surface.

Further, since the combustion gas of each burner flows in the axial direction at the measurement position of the metal temperature of the combustor liner and the combustion gas temperature near the wall surface of the liner, the corresponding burner is determined by matching the position of each burner in the circumferential direction. Can be clarified.

[0014]

FIG. 1 is a structural view of a gas turbine combustor. After the air compressed by the compressor 1 is sent to the combustor 2, the air is compressed by the combustion gas generated in the combustor 2.
Drive. Reference numeral 4 denotes a generator driven by the turbine 3.
At the compressor outlet, a compressor discharge air temperature sensor 5 is attached.

The gas turbine is provided with a plurality of combustors, and the figure mainly shows one of the cans. Other combustors have similar paths. A plurality of combustion burners are installed on the upstream side of the combustor inner cylinder 6, and one system of a diffusion combustion burner 7 (F1 burner) is provided at the axial center position.
Around the premixed combustion burners 8a-d (F2-1-4)
Burners) (four systems in this figure). Each burner is provided with a flow control valve 9a-e (GCV).

The fuel supply path can include a base fuel supply system, a plurality of mother fuel supply systems branched from the base fuel supply system, and a plurality of fuel supply systems branched from the mother fuel supply system.

For example, the base fuel supply system branches off from the base fuel supply system FA, and one of the base fuel supply systems F2A
Is one of the F2 burners of each combustor (8a, 8
a ', 8a "Fuel supply systems (F2-1, F2-1', F2-
1 "and a system corresponding to a burner not shown).

The burner 8b for premixed combustion is a burner 8b of another combustor.
b 'and 8b "and other applicable burners,
It has a configuration similar to that of the case.

The branch section may supply and distribute fuel to each path by a manifold. For example, an SRV (pressure regulating valve) 10b is connected to the mother fuel supply system.
Is provided. The fuel flow to the burner can be increased or decreased by the pressure regulating valves 10a and 10b (10b-1, 10b-2, etc.).

This is particularly effective when valves corresponding to 9a to 9c are not provided.

A ring-shaped flame stabilizer 11 having a wedge-shaped cross section is provided at the tip of the premixed combustion burner. A circulating flow region is formed downstream of the flame stabilizer, and a stable premixed combustion is performed by mixing the high-temperature combustion gas and the unburned gas in the circulating flow. Temperature sensors 12a to 12d are attached to measure the metal temperature of the flame stabilizer,
The detected temperature signal is input to the fuel flow control device 13 and the GCV is operated by a fuel flow command output from the fuel flow control device 13.

First, a method of operating the gas turbine combustor used in this embodiment will be described. FIG. 2 is a graph in which the horizontal axis represents the gas turbine load, the vertical axis represents the NOx concentration generated from the combustor, and the flow rate of the fuel supplied to each burner. As shown in FIG. 2, during normal operation, the load at which fuel is supplied to each combustion burner is determined according to an increase in the gas turbine load. The figure shows one system for a diffusion burner, four systems for a premixed burner, and The number of fuel switching points is the same as the number of premixed fuel systems, that is, four stages. When the load is low, the fuel is supplied only to the burner for diffusion combustion (F1 burner), and the diffusion combustion alone operation is performed. When the first-stage premixed combustion start load is reached, the F1 fuel is first reduced, and the reduced amount is fed to the F2-1 burner. This operation lowers NOx, but after switching, NOx increases again as the fuel-air ratio increases with the load increase. At the second stage premix combustion start load, the F1 and F2-1 fuels are reduced, and the reduced amount is fed to the F2-2 burner. In the following, F2-
3, the F2-4 burner is ignited, and at a high load after the fourth stage switching, the entire fuel system is operated to increase the load to the rated load. The fuel supply amount to each of the burners is 9a-e.
This is performed by adjusting the opening degree of the valve 10a or the valve 10a or 10b. From the NOx characteristic curve of FIG. 2 for the gas turbine load by this switching method, the load range in which the premix combustion is performed is widened, so that the NOx can be reduced over a wide load range.

Next, control of the gas turbine combustor used in this embodiment will be described. As an example of a method of detecting the combustion state of the F2 burner in the combustion chamber, measurement of the temperature of a flame stabilizer metal installed at the tip of the F2 burner as shown in FIG. 1 is used. A change in the combustion gas temperature of the premixed flame can be regarded as a change in the temperature of the flame stabilizer metal. Therefore, a thermocouple is attached to the flame stabilizer to monitor the combustion state of the F2 burner.

The thermocouples Ai to Di (i is the number of combustors)
As shown in the figure, the burners are installed in the flame stabilizers corresponding to the premix combustion burners F2-1i to 4i. For example, if the number of combustor cans per gas turbine is 14 cans, the detected temperature signal is 4 points x 14 cans = 56 points, but the number of F2 burners operated by the load changes because the load changes. Then, the detection value from the F2 burner that has started combustion is selected from the detection signals for monitoring. Therefore, the number of monitoring temperature signals is 1 depending on the load.
It changes in the range of 4 (the number of combustors) × 1 to 4 (the number of premix burner switching). It is not always necessary to use the values of all the cans as the measured values, but values of several cans may be used.

A control device for detecting a combustion abnormality based on a signal from a combustion state detecting means such as a misfire and controlling the supplied fuel will be described below.

FIG. 3 shows a partial misfire of the F2 burner (partial misfire).
5 is a fuel flow control flow in the case where is detected. First, of the monitoring temperature signals, the difference between the flame stabilizer metal temperature minimum value Tmin and the compressor discharge air temperature Tcd is calculated as the allowable minimum temperature difference ΔTal.
Compare with Here, ΔTal is obtained by correcting the theoretical rise in gas temperature due to combustion by the temperature drop when the metal temperature is detected due to radiation, heat transfer to the surrounding fluid, and the like. Temperature difference (T
If (min−Tcd) is lower than the allowable minimum temperature difference ΔTal, it is determined that a partial misfire has occurred, and the flow rate Fmin of the fuel system of the F2 burner corresponding to Tmin and the average flow rate F of all the burning F2 burners per fuel system. performing deviation with the F2 fuel flow distribution ratio to increase the _X ratio (Fmin / F _X).
If ΔTal or more, it is determined that the combustion state is normal and the control command for the F2 fuel flow distribution ratio deviation is released. The deviation is set by controlling the flow rates of all the fuel systems in the burner of the F2 in operation. If all four F2 burners are in operation, Fmin is increased at a preset rate while the increase is reduced evenly from the other three systems. As described above, each fuel supply system (F2-1, F2-1 ', F2
−1 ″...) Is supplied from one mother fuel supply system F2A, and the other configuration is the same. When the opening of the valve located at the position of the flow control valve 10b-1 of F2A is increased, Adjustment valve (F2B.e) of the mother fuel supply system (F2B.etc ...)
The opening of the valve at the position tc...) can be closed little by little to balance the flow rate of the fuel flowing from the base fuel supply system FA. By this operation, Fmin is increased while the average flow rate F _X is kept constant, and the flow rate deviation (Fmin−F _X ) exceeds the allowable amount ΔFa of the fuel flow rate increase amount or the temperature difference (T
min−Tcd) is equal to or greater than the allowable minimum temperature difference ΔTal.
A control loop for operating the fuel flow rate of the in system in the increasing direction and the other three systems in the decreasing direction is formed. Here, the allowable value ΔFa of the fuel flow rate increase amount is a value determined from the fuel-air ratio upper limit side of the Fmin system at which the flow rate becomes maximum. Flow deviation (Fmin-
If F _X ) exceeds the allowable value ΔFa of the fuel flow increase amount, a run-back operation is performed to reduce the load to below the applicable F2 burner ignition load of the Fmin system to protect the combustor. The degree of the drop is a degree at which the load is reduced by closing the flow control valve 10b of the mother fuel supply system to which the F2 burner determined to be abnormal belongs. Although the case F2 burners in operation is 2 or 3 systems is the same as that described above, for the case of one system is a Fmin = F _X, the control is performed by replacing the Fmin of F _X = default values. To perform fuel flow increased Fmin system in the control method with a certain time rate of change, the average flow rate F elapse before exceeding the increase in tolerance ΔFa for _X, and the threshold value for the run-back operation proceeds You can also.

Thus, when the fuel-air ratio of the premixed gas supplied to one premixed combustor is reduced, the fuel-air ratio is increased to a fuel-air ratio that can stably burn the fuel-air ratio of the misfired burner. Can be enhanced.

Therefore, even if the burner becomes difficult to ignite and becomes unstable, it is possible to increase the fuel flow rate from some of the F2 burners by changing the fuel state as described above. To supply a high premixed gas), and improve the combustion conditions to ensure re-ignition or stable combustion.

As a result, even if the ignition becomes difficult under the same conditions as the normal conditions before the control, it is possible to make the combustion condition easier to ignite and reignition can be performed.
A highly operable gas turbine can be provided.

As described above, the mother fuel supply system FA branches upstream from the base fuel supply system, and the flow rate of fuel supplied to the F2 burner 8a of the gas turbine combustor is adjusted mainly by the valve such as 10b. In this case, the mother fuel supply system F2A may be increased by reducing the flow rate flowing to another mother fuel supply system, and the fuel flow rate supplied to the F2 burners 8a and 8a 'and 8a "may be increased. .

A control device for detecting a combustion abnormality based on a signal from another combustion state detecting means and controlling the flow rate of supplied fuel will be described below.

FIG. 4 is a graph showing the relationship between the combustion state of each F2 burner and the F
2 is a fuel flow control flow for correcting the fuel-air ratio deviation of each F2 burner by adjusting the fuel flow distribution ratio and making the fuel-air ratio uniform. First, of the monitoring temperature signals,
At the temperature detected by the thermocouples Ai to Di (i is the number of combustors), the maximum value Tmax and the minimum value Tmin of the flame stabilizer metal temperature are calculated from the average values T _{XA to} T _XD of all cans for each mother fuel supply system. Is selected, and the temperature deviation Tmax-Tmin is compared with the temperature deviation allowable value ΔTa2. Here, ΔTa2 is the actual value of the metal temperature deviation when the fuel-air ratio of each F2 burner is made uniform. The detection of the flame stabilizer metal temperature deviation is performed after the ignition of the F2-2 burner, and is performed by controlling the flow rate of two of the operating F2 burners. When the temperature deviation exceeds the allowable value, Fmax is reduced at a preset rate with respect to the flow rate Fmax of the fuel system of the F2 burner corresponding to Tmax and the flow rate Fmin of the fuel system of the F2 burner corresponding to Tmin. Is increased by the decrease. The flow rate adjustment is performed by, for example, each flow rate adjustment valve 1
In the case where a pressure adjusting valve (9a-9b) for performing the operation at 0b is provided, the operation may be performed at the valve. With this operation, the temperature deviation Tmax-Tmin is reduced while keeping the flow rate of the base fuel supply system FA constant, and a control loop is formed to repeat the above operation until the temperature deviation falls within the temperature deviation allowable value ΔTa2. If the temperature deviation is within the allowable value, it is determined that the combustion state is normal, and the flow rate is controlled as planned.

According to the above method, the NO during operation of the gas turbine
x rise can be prevented and a stable combustion margin can be secured, and the protection of the gas turbine such as a load drop by detecting a burner partial misfire can be satisfactorily performed. Therefore, a highly operable gas turbine can be provided.

Further, in the above method, the flame holder metal temperature is used as the combustion state detecting means of each F2 burner. However, the metal temperature of the combustor liner shown in FIG. 5 and the combustor liner shown in FIG. There is a temperature of the combustion gas flowing in the vicinity, and these can also be used in the same manner as in the embodiment of the combustion stabilization control method by detecting the metal temperature of the flame stabilizer.

When the metal temperature or the combustion gas temperature of the combustor liner is used as the detecting means, the thermocouple for measuring the metal temperature or the combustion gas temperature is the same as that for the flame stabilizer so that each of the four F2 burners can be specified and measured. It is installed at four places in the circumferential direction and at an axial position where a change in combustion gas temperature can be detected. In this case, the minimum allowable temperature difference ΔTal and the allowable temperature deviation value ΔTa2 are different from those when the flame stabilizer metal temperature is used, due to the difference in the temperature measurement location.

FIG. 7 shows a means for measuring the metal temperature of the combustor liner in a non-contact manner. A substance having a high heat absorption rate is attached to the liner side and the tip of the temperature measuring probe 100 by using a medium as a temperature medium. The temperature medium 103 on the liner side increases in temperature due to heat conduction from the liner, and the temperature medium 101 on the probe side increases by radiation to the probe side through the space. By measuring the temperature mediated by the probe-side temperature with a thermocouple, a control signal can be obtained in the same manner as in the control method using the flame stabilizer metal temperature, the liner metal temperature, and the gas temperature.

In general, a gas turbine is provided with a plurality of combustors, and if a specific can is misfired,
The load decreases and the power generation efficiency decreases. When the load is controlled to be constant, if the fuel flow rate is increased to compensate for the load drop, the normally burning can becomes overloaded, causing vibration due to abnormal combustion and overheating of the metal temperature of the combustor liner, etc. This may cause thermal stress or the like to be applied to the liner, further increase the circumferential combustion gas temperature difference at the turbine inlet, and increase the thermal stress of the moving blades and the like. However, this control can suppress such a risk.

One premixed combustion nozzle 8a of the gas turbine combustor is provided with a fuel supply system F2-1 for supplying fuel to the premixed combustion nozzles 8a 'of the other combustor and one mother fuel supply system. Fuel is branched and supplied from F2A,
A configuration in which one mother fuel system F2A communicates upstream with the base fuel supply system FA. In addition, the control can be effectively performed even in a configuration in which the fuel supply system FA is connected to supply the fuel to the mother fuel system F2A and another mother fuel supply system.

For example, if the number of burners per gas turbine is 14 and the number of burners per can is 5 for diffusion combustion and for premix combustion, the number of burners per can is 5 per gas turbine. The number of burners is 70. Therefore, since one burner has a small contribution rate to the whole of 1/70 ≒ 1.4%, the temperature deviation of the exhaust gas at the gas turbine outlet due to the misfire of one burner is the temperature generated from the flow deviation of the fuel nozzle. This is because the difference is not significant compared to the deviation.

As described above, in the combustor having a large number of burners per can, when one misfire occurs in one premixed burner in a certain can, compared with the case where the number of burners per can is small, the burner outlet is smaller. The decrease in combustion gas temperature is reduced. The circumferential deviation of the exhaust gas temperature at the gas turbine outlet is also reduced.

In order to perform stable combustion while reducing NOx, the combustion state of each premixed combustion burner can be controlled uniformly.

The combustion state of each premixed combustion burner is greatly affected by the fuel-air ratio, which is the mass flow ratio between fuel and air.
Since the x concentration increases exponentially with an increase in the fuel-air ratio, if a deviation occurs in the fuel-air ratio of each premixed combustion burner, NOx will increase as compared with a case where it is uniform. On the other hand, in a premixed combustion burner, generally, when the fuel-air ratio increases, a flame-back phenomenon in which the flame returns against the flow of the premixed gas tends to occur. Therefore, according to the present embodiment, the fuel-air ratio of each premixed combustion burner becomes non-uniform and the margin is suppressed from being narrowed, and stable combustion can be performed.

[0043]

According to the present invention, in a combustor having a plurality of premixed burners in one combustor inner cylinder and a plurality of fuel systems for supplying fuel to these burners, the combustion state of each burner is determined. By controlling the fuel-air ratio accordingly,
It is possible to prevent a rise in NOx and secure a stable combustion margin during operation of the gas turbine, and to protect the gas turbine satisfactorily, such as load reduction by detecting burner partial misfire.

[Brief description of the drawings]

FIG. 1 is a sectional view of a control device and a combustor according to the present invention.

FIG. 2 is an example of NOx characteristics with respect to a gas turbine load, an example of a fuel flow rate line, and a sectional view of a combustor.

FIG. 3 is a fuel control flow for a partial misfire of a premix burner.

FIG. 4 is a fuel control flow for a fuel flow deviation of a premix burner.

FIG. 5 is an example of a temperature deviation detecting means of the combustor liner.

FIG. 6 shows an example of a means for detecting a combustion gas temperature deviation near the wall surface of a combustor liner.

FIG. 7 shows an example of a means for detecting a temperature deviation of a combustor liner by a non-contact method.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI F23R 3/34 F23R 3/34 (72) Inventor Nariki Kobayashi 7-2-1, Omikamachi, Hitachi City, Hitachi City, Ibaraki Prefecture Hitachi, Ltd. Within Electricity Development Division (72) Inventor Kazuyuki Ito 7-2-1, Omika-cho, Hitachi City, Ibaraki Prefecture Within Hitachi Electric Power & Electricity Development Division

Claims (7)

[Claims] 1. A diffusion burner section for performing diffusion combustion, and a premix burner section is provided on an outer peripheral side of the diffusion burner section by premixing and burning a premixed air of fuel and air. A gas turbine comprising a plurality of premix burners having control means for controlling the amount of fuel in an air-fuel mixture, the combustion turbine being provided with a plurality of premix burners, and a combustion liner for burning fuel supplied from the diffusion burner section and the premix burner section. A gas turbine comprising a plurality of combustors and a turbine driven by combustion gas supplied from the plurality of gas turbine combustors, comprising: means for detecting abnormality of a combustion state of each of the premix burners; Is communicated, a misfire state of the premix burner is detected based on the signal, and a fuel flow rate supplied to the premix burner in the detected misfire state is increased to perform combustion. Gas turbine characterized by comprising a control device for controlling to continue operation to ensure. 2. The method according to claim 1, wherein when the amount of increase in the fuel has reached a predetermined value or when the misfire state has not been resolved even after a lapse of a predetermined time from the start of the increase in the fuel flow rate, A gas turbine, comprising: a control device that stops fuel supply to a mixing burner and controls the gas turbine to operate by reducing the load of the gas turbine by an amount corresponding to the premixing burner. 3. The gas turbine according to claim 1, wherein the misfire state is a state in which a difference between a discharge air temperature of the compressor and a premix combustion temperature is smaller than a predetermined value. 4. The misfire state according to claim 1, wherein the premixed combustion temperature of the one premixing nozzle is lower than an average value of the premixed combustion temperature of the premixing nozzle of the gas turbine combustor by a predetermined value or more. A gas turbine, wherein the gas turbine is in a closed state. 5. The combustor liner according to claim 3, further comprising a liner temperature detecting means at a position corresponding to each of the premix nozzles, wherein the premix combustion temperature is determined by the liner temperature detecting means. A gas turbine characterized by a temperature calculated based on a detected temperature. 6. The combustor liner according to claim 3, wherein the combustor liner is provided with a combustion gas temperature detecting means at a position corresponding to each of the premixing nozzles, and wherein the premixed combustion temperature is equal to the combustion gas temperature. A gas turbine, wherein the temperature is calculated based on a temperature detected by a detection unit. 7. A diffusion burner for performing diffusion combustion, and a plurality of premix burners for premixing and burning a premixed air of fuel and air on an outer peripheral side of the diffusion burner are arranged around the diffusion burner. A plurality of mother fuel supply systems having control means for controlling the amount of fuel for supplying fuel to the premix burner; and branching off from the mother fuel supply system to supply fuel to the premix burner of one of the gas turbine combustors. A plurality of fuel supply paths including a plurality of fuel supply systems to be supplied are provided corresponding to the premix burners provided in the gas turbine combustor, and the fuel supplied from the diffusion burner section and the premix burner section is burned. A plurality of gas turbine combustors each including a combustion liner to be operated, and a turbine driven by combustion gas supplied from the plurality of gas turbine combustors. Calculate the average value of the combustion temperature of the premix burner for each system, reduce the fuel supply amount to the premix burner of the system with the maximum average value, and reduce the fuel supply amount to the premix burner of the system with the minimum average value. A gas turbine, comprising: a control device that controls so as to increase a fuel supply amount of a gas turbine.