GAS TURBINE COMBUSTION DEVICE AND ITS OPERATING METHOD

Abstract

A gas turbine combustion device comprising: a burner (8) including: a startup fuel line (57) in which a startup fuel circulates; a first main fuel line (59) in which a main fuel circulates; a second main fuel line (60) in which the main fuel circulates; a fuel mixer (61) to which the startup fuel line (57) and the first main fuel line (59) are connected; an inner fuel nozzle (21) to which the fuel mixer (61) is connected; a plurality of outer fuel nozzles (22, 23) to which the second main fuel line (60) is connected; a startup fuel control valve (64) provided in the startup fuel line (57); a first fuel control valve (65) provided in the first main fuel line (59); a second fuel control valve (66) provided in the second main fuel line (60);and a controller (70) configured to control the startup fuel control valve (64), the first fuel control valve (65), and the second fuel control valve (66), wherein the controller (70) executes procedures including: (1) increasing an opening degree of the startup fuel control valve (64) to supply the startup fuel to the inner fuel nozzle (21), (2) increasing an opening degree of the second fuel control valve (66) to supply the main fuel to a plurality of outer fuel nozzles (22, 23) when a gas turbine load increases to a first setpoint, and (3) increasing an opening degree of the first fuel control valve (65) to supply a gaseous fuel mixed from the startup fuel and the main fuel to the inner fuel nozzle (21) when the gas turbine load further increases to a second setpoint.

Description

BACKGROUND OF THE INVENTION1. Field of the InventionThe present invention relates to a gas turbine combustor and its method of operation.2. Description of Related ArtIn recent years, from the standpoint of minimizing geothermal heating, utilization of raw materials and reducing power generation cost, it has been required to effectively use by-product gas such as coke oven gas produced as a by-product in iron hats and exhaust gas produced as a by-product in oil refinery. Moreover, attention has been paid to an integrated coal gasification combined cycle (IGCC) that gasifies coal, which is an abundant working medium, and generates electric power. In the IGCC, measures for reducing carbon dioxide (CO 2- emissions) are currently being tested by a system (carbon separation and storage (CCS)) that separates and stores carbon in a gaseous fuel supplied to a gas turbine. Since the gaseous fuel mainly contains hydrogen (H 2) it is possible to reduce CO 2- emissions and contribute to minimizing geothermal heating compared to natural gas (mainly containing methane) normally used in gas turbines. In addition, power generation by a pure hydrogen fuel is being studied for realizing a future hydrogen-based society. When electric power can be generated using pure hydrogen as fuel, emission-free power generation can be realized without CO 2- emissions. In this sense, a hydrogen-containing fuel is considered promising from the standpoint of minimizing heating of the earth, utilization of raw materials and reduction of power generation cost.However, burning of hydrogen results in a local increase of a maximum adiabatic flame temperature of a combustion zone as compared with a case of burning natural gas; thus, there is concern of an increase in emissions of nitrogen oxides (NOx) which are an environmental pollutant in a combustion gas. Moreover, due to a higher combustion speed of hydrogen than natural gas, a flame rebound of a flame to a burner portion upstream of a combustion device may occur, causing the concern of lowering the reliability of the combustion device. To address the problems, a lean burn type combustion apparatus is known which is provided to reduce NOx emissions and prevent back flame of a flame by improving fuel dispersibility and preventing local formation of a high temperature flame (Patent Document 1: JP 2003-148 734 A, etc., and the like). The combustion apparatus of this type is configured with, for example, an air hole plate having a plurality of air holes and a plurality of fuel nozzles, injecting a fuel from each fuel nozzle into the corresponding air hole, and supplying a coaxial jet formed of a fuel flow and an air flow surrounding this fuel flow to a combustion chamber.In the case of using a hydrogen-containing fuel as a fuel of a gas turbine, there is a concern that, when ignition fails in the combustion device, unburned hydrogen-containing fuel is discharged from the combustion device, stagnant in the turbine, and burned in the turbine. In order to take measures against the problem, an operation method of supplying a hydrogen-containing fuel after ignition of a startup fuel containing no hydrogen is known. As one type of the operation method, an example of igniting an oil fuel and changing the oil fuel to a hydrogen-containing fuel is known (Patent Document 2: JP 2014-105 601 A and Patent Document 3: JP 2018-71 354 A). In addition, an example of co-combustion for using a part of a plurality of main burners with natural gas and a remainder thereof with a hydrogen-containing fuel after igniting a pilot burner disposed at a center with the natural gas is known (Patent Document 4: JP 2016-75 448 A).Patent Document 5 discloses an operation method for a gas turbine in which a burner having a fuel nozzle for injecting fuel into a combustor and an air nozzle for supplying combustion air to the combustor is equipped with a starting fuel supply system that supplies the starting fuel used for ignition and starting of the gas turbine. When the gas turbine is started, starting fuel and fuel are supplied to the combustion chamber through the fuel nozzle. The supply of the starting fuel is stopped before the gas turbine reaches the idle speed.Keep ListPatent DocumentsPatent Document 1: JP 2003-148734 APatent Document 2: JP 2014-105601 APatent Document 3: JP 2018-71354 APatent Document 4: JP 2016-75448 APatent Document 5: JP 2010-133 339 AIn JP 2014-105 601 A, JP 2018-71 354 A, and JP 2016-75 448 A, it is impossible to inject the hydrogen-containing fuel from fuel nozzles used in injecting startup fuel. Due to this, when a burning operation shifts to a single-ignition operation of the hydrogen-containing fuel, it is impossible to supply the fuel to fuel injection zones of the fuel nozzles for the startup fuel, and dispersibility of a gaseous fuel deteriorates, resulting in a disadvantage in NOx emission reduction.It is an object of the present invention to provide a gas turbine combustor and its operation method that can stably ignite a hydrogen-containing fuel using a gaseous fuel containing no hydrogen and improve dispersibility of the hydrogen-containing fuel.SUMMARY OF THE INVENTIONTo achieve the object, the present invention provides a gas turbine combustor including a burner including: a startup fuel line in which startup fuel circulates; a first main fuel line in which main fuel circulates, a second main fuel line in which main fuel circulates; a fuel mixer to which the startup fuel line and the first main fuel line are connected; an inner fuel nozzle to which the fuel mixer is connected; a plurality of outer fuel nozzles to which the second main fuel line is connected; a startup fuel control valve provided in the startup fuel line; a first fuel control valve provided in the first main fuel line; and a second fuel control valve provided in the second main fuel line. The gas turbine combustor further comprises a controller configured to control the startup fuel control valve, the first fuel control valve, and the second fuel control valve, wherein the controller executes procedures including: (1) increasing an opening degree of the startup fuel control valve to deliver the startup fuel to the inner fuel nozzle, (2) increasing an opening degree of the second fuel control valve to deliver the main fuel to a plurality of outer fuel nozzles when a gas turbine load increases to a first target value, and (3) increasing an opening degree of the first fuel control valve to deliver a mixed gaseous fuel of the startup fuel and the main fuel to the inner fuel nozzle when the gas turbine load further increases to a second target value.According to the present invention, it is possible to stably ignite a hydrogen-containing fuel using a gaseous fuel containing no hydrogen and improve dispersibility of the hydrogen-containing fuel.BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1 is a schematic configuration diagram of a gas turbine power plant configured with a gas turbine combustor according to a first embodiment of the present invention; FIG. 2 illustrates a burner provided in the gas turbine combustor according to the first embodiment of the present invention, the burner being viewed from a combustor; FIG. 3 is an explanatory diagram of a gas turbine combustion device operation method (at startup time) according to the first embodiment of the present invention; FIG. 4 is an explanatory diagram of a gas turbine combustion device operation method (at stop time) according to the first embodiment of the present invention; FIG. 5 is an explanatory diagram of advantages of the present invention; FIG. 6 is a schematic configuration diagram of a gas turbine power plant configured with a gas turbine combustor according to a second embodiment of the present invention; FIG. 7 is a schematic configuration diagram of a gas turbine power plant configured with a gas turbine combustor according to a third embodiment of the present invention; FIG. 8 illustrates a burner provided in the gas turbine combustor according to the third embodiment of the present invention, the burner being viewed from a combustor; FIG. 9 is an explanatory diagram of a gas turbine combustion device operation method (at startup time) according to the third embodiment of the present invention; FIG. 10 is an explanatory diagram of a gas turbine combustion device operation method (at the stop time) according to the third embodiment of the present invention; FIG. 11 is a schematic configuration diagram of a gas turbine power plant configured with a gas turbine combustor according to a fourth embodiment of the present invention; FIG. 12 illustrates a burner provided in the gas turbine combustor according to the fourth embodiment of the present invention, the burner being viewed from a combustor; FIG. 13 is an explanatory diagram of a gas turbine combustion device operation method (at startup time) according to the fourth embodiment of the present invention; and FIG. 14 is an explanatory diagram of a gas turbine combustion device operation method (at the stop time) according to the fourth embodiment of the present invention.DESCRIPTION OF THE PREFERRED EMBODIMENTSEmbodiments of the present invention will be described below with reference to the drawings.First Embodimentgas turbine power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plant power plantFIG. 1 is a schematic configuration diagram of a gas turbine power plant configured with a gas turbine combustion apparatus according to a first embodiment of the present invention. FIG. 2 illustrates a burner provided in the gas turbine combustion apparatus according to the first embodiment of the present invention, the burner being viewed from a combustor.A gas turbine power plant 1 is configured with an air compressor 2, a gas turbine combustor (hereinafter, abbreviated as "combustor") 3, a turbine 4, and an electric generator 6. The air compressor 2 draws in, compresses, and supplies a compressed air a 2 to the combustor 3. the combustor 3 mixes the compressed air a 2 with a gaseous fuel (a startup fuel f 1 and a main fuel f 2) and burns to generate a combustion gas g 1. The turbine 4 is driven by the combustion gas g 1 generated in the combustion device 3, and the combustion gas g 1 driving the turbine 4 is discharged as exhaust gas g 2. The electric generator 6 is driven by a rotational power of the turbine 4 and generates electric power. It is to be noted that the turbine 4 is driven by a starting motor 7 only at the time of startup.gas turbine combustor;The combustion device 3 is mounted on a casing (not shown) of the turbine 4, and is configured with a liner (a combustion liner) 12, a flow sleeve (an outer casing) 10, a burner 8, and a fuel supply system 200. The liner 12 is a cylindrical member and forms a combustion chamber 5 therein. the flow sleeve 10 is a cylindrical member having an inner diameter larger than an inner diameter of the liner 12 and surrounding an outer periphery of the liner 12 to form a cylindrical air flow passage 9. An end portion of the flow sleeve 10 on an opposite side to the turbine 4 (a left side in FIG. 1 ) is closed by an end cover 13. The compressed air a 2 from the air compressor 2 circulates in the air flow passage 9 formed on the outer periphery of the liner 12 by the flow sleeve 10 in a direction away from the turbine 4, and an outer peripheral surface of the liner 12 is subjected to convection cooling by the compressed air a 2 flowing in the air flow passage 9. In addition, many holes are formed in a wall surface of the liner 12, a partial compressed air a 3 of the compressed air a 2 flowing in the air flow passage 9 flows into the combustion chamber 5 through these holes, and the inner circumferential surface of the liner 12 is subjected to film cooling by the partial compressed air a 3. Moreover, the compressed air a 2 passing through the air flow passage 9 and arriving at the burner 8 is ejected to the burner 8 together with the gaseous fuel supplied from the fuel supply system 200, and the gaseous fuel ejected together with the compressed air a 2 is burned. In the combustor 5, a gaseous fuel mixed from the compressed air a 2 and the gaseous fuel is burned to generate the combustion gas g 1, and the combustion gas g 1 is supplied to the turbine 4 via a transition piece (not illustrated).As shown in FIG. 1, only one burner 8 is disposed at an inlet port of the liner 12 (an opening in the end portion on the opposite side to the turbine 4), and is configured with an air hole plate 20, fuel nozzles 21 to 23, and a fuel manifold (a fuel head portion) 24.The air hole plate 20 is a circular plate that is coaxial with the liner 12 and disposed at the inlet port of the liner 12 (the opening in the end portion on the opposite side to the turbine 4). The air hole plate 20 is configured with a plurality of air holes 51 to 53 that guide the compressed air a 2 to the combustor 5. The plurality of air holes 51 to 53 configure a plurality of concentric annular rows about a central axis O of the liner 12. The air holes belonging to a first (innermost) row are the air holes 51, those belonging to a second annular row are the air holes 52, and those belonging to a third (outermost) annular row are the air holes 53. In the present embodiment, the air holes 51 to 53 have rotary joints, and an outlet opening of each air hole is misaligned with a circumferential side with respect to its inlet port.The fuel nozzles 21 to 23 are supported by the fuel distributor 24 and are disposed opposite to the combustor 5 above the air hole plate 20. The fuel nozzles 21 to 23 correspond to the air holes 51 to 53 in number and position (one fuel nozzle corresponds to one air hole) and configure, together with the air holes 51 to 53, the plurality of concentric annular rows about the central axis O of the liner 12. The fuel nozzles 21 to 23 have injection ports oriented to inlet ports of the respective air holes, and inject the gaseous fuel to the respective air holes. By injecting the fuel from many fuel nozzles to the corresponding air holes in this manner, a coaxial jet of the fuel and the air in which the vicinity of a fuel flow is covered with an air flow is distributed from each air hole in the combustion chamber 5 and injected into it.Note that the numbers of fuel nozzles and air holes of the outer annular row are larger due to a difference in a circumference of a circle between the annular rows. In other words, the numbers of the fuel nozzles 21 and the air holes 51 (six in each example of FIG. 2 ) in the first (the innermost) row are smaller than those of the fuel nozzles 22 and the air holes 52 (12 in each example of FIG. 2 ) in the second row. The numbers of the fuel nozzles 22 and the air holes 52 in the second row are smaller than those of the fuel nozzles 23 and the air holes 53 (18 in each case in the example of FIG. 2 ) in the third (outermost) row.The fuel distributor 24 is a member that distributes and supplies the fuel to the fuel nozzles 21 to 23, and is configured with a plurality of fuel cavities 25 and 26 contained therein. Each of the fuel cavities 25 and 26 is a space that plays a role in distributing and supplying the gaseous fuel to a plurality of fuel nozzles belonging to the respective annular rows. The fuel cavity 25 is formed in a columnar shape on the central axis 0 of the liner 12, and the fuel cavity 26 is formed in a cylindrical shape so as to surround an outer periphery of the fuel cavity 25. In the present embodiment, the fuel nozzles 21 are connected to the fuel cavity 25 and the fuel nozzles 22 and 23 are connected to the fuel cavity 26. When supplied to the fuel cavity 25, the gaseous fuel is distributed to the fuel nozzles 21 arranged in the innermost annular row and is then discharged, and the gaseous fuel discharged from the fuel nozzles 21 is discharged together with the compressed air a2 from the air holes 51 to the combustor 5. When supplied to the fuel cavity 26, the gaseous fuel is distributed to the fuel nozzles 22 and 23 arranged in the second and third annular rows, and then discharged, and the gaseous fuel discharged from the fuel nozzles 22 and 23 is discharged to the combustor 5 together with the compressed air a 2.The fuel supply system 200 is configured with fuel supply sources 55 and 56, a startup fuel line 57, a main flow line 58, main fuel lines 59 and 60, a fuel mixer 61, fuel shut-off valves 62 and 63, and fuel control valves 64 to 66.The fuel supply source 55 is a source for supplying the startup fuel f 1. As the startup fuel f 1, a fuel containing no hydrogen or a gaseous fuel having a hydrogen content less % (e.g., 5%) such as a hydrocarbon fuel is used. Representative examples of the hydrocarbon fuel include natural gas mainly containing methane and petroleum gas mainly containing propane or butane. The fuel supply source 56 is a source for supplying the main fuel f 2. As the main fuel f 2, a hydrogen-containing fuel having a hydrogen content in the range of from a few % (e.g., 5%) to several tens % or higher, such as a byproduct gas, is used. Pure hydrogen (a hydrogen content of 100%) is one type of the hydrogen-containing fuel.The startup fuel line 57 extends from the fuel supply source 55, and the startup fuel f 1 circulates in the startup fuel line 57. the main flow line 58 extending from the fuel supply source 56 branches into the first main fuel line 59, and the second main fuel line 60 and the main fuel f 2 circulate in these main fuel lines 59 and 60. the startup fuel line 57 and the first main fuel line 59 are connected to the fuel mixer 61 and are united with each other. The fuel mixer 61 is connected to the fuel cavity 25 via a communication passage 68, and is connected to the inner fuel nozzles 21 via the fuel cavity 25. The second main fuel line 60 is connected to the fuel cavity 26 and connected to the outer fuel nozzles 22 and 23 via the fuel cavity 26. The fuel cut valve 62 and the fuel control valve (startup fuel control valve) 64 are provided in the startup fuel line 57. In addition, the fuel control valve 65 (the first fuel control valve) is provided in the first main fuel line 59 and the fuel control valve 66 (the second fuel control valve) is provided in the second main fuel line 60. The fuel cut valve 63 is provided between a branching portion in which the main flow line 58 branches to the main fuel lines 59 and 60 and the fuel supply source 56 (i.e., provided in the main flow line 58).Opening the fuel cut valve 62 enables supply of the startup fuel f 1 to the startup fuel line 57 and closing the fuel cut valve 62 causes cut-off of supply of the startup fuel f 1 to the startup fuel line 57. opening the fuel cut valve 63 enables supply of the main fuel f 2 to the main fuel lines 59 and 60, and closing the fuel cut valve 63 causes cut-off of supply of the main fuel f 2 to the main fuel lines 59 and 60. The fuel control valves 64 to 66 each play a role in controlling a flow rate of the fuel in response to an opening degree and can cut off a flow of the fuel by being placed in a fully closed state.For example, releasing the fuel cut valve 62, closing the fuel cut valve 63 and increasing the opening degree of the fuel control valves 64 from the fully closed state cause an increase in a supply flow rate of the startup fuel f 1 to the fuel cavity 25 and only the startup fuel f 1 is ejected from the fuel nozzles 21. Conversely, releasing the fuel cut valve 63, closing the fuel cut valve 62, and increasing the opening degree of the fuel control valves 65 from the fully closed state cause an increase in a supply flow rate of the main fuel f 2 to the fuel cavity 25 and only the main fuel f 2 is ejected from the fuel nozzles 21. Moreover, releasing both the fuel cut valves 62 and 63 and increasing the opening degree of the fuel control valves 64 and 65 from the fully closed states cause the startup fuel f1 and the main fuel f2 to be mixed in the fuel mixer 61 and a gaseous fuel mixed from the two fuels is discharged from the fuel nozzles 21 via the fuel cavity 25. In addition, increasing the opening degree of the fuel control valves 66 from the fully closed state to a state of releasing the fuel cut valve 63 causes an increase in the supply flow rate of the main fuel f 2 to the fuel cavity 26 and only the main fuel f 2 is ejected from the fuel nozzles 22 and 23.While a case where the number of annular rows of air holes is three is exemplified in the present embodiment, the number of annular rows of air holes may be two or may be equal to or greater than four. Increasing the number of rows enables the combustion device 3 to be compatible with a high-capacity gas turbine and improving operation controllability.Moreover, the combustion device 3 is equipped with a controller 70 that controls the fuel cut valves 62 and 63 and the fuel control valves 64 to 66. The controller 70 controls the fuel cut valves 62 and 63 and the fuel control valves 64 to 66 based on a gas turbine load detected by a sensor 71. In the present embodiment, the electric power output from the electric generator 6 or a rotational speed of the turbine 4 is measured as the gas turbine load, and a power meter or a rotation sensor may be used as the sensor 71. In addition, because of a proportional relationship between the gas turbine load and a flow rate of the fuel, a flowmeter that measures a supply flow rate of the fuel or an aperture meter that measures the opening degree of the fuel control valves 64 to 66 may be used as the sensor 71.The controller 70 is a computer and is configured with an input interface, a read only memory (ROM) such as an erasable programmable read only memory (EPROM), a random access memory (RAM), a central processing unit (CPU), a timer, an output interface, and the like. A detection signal output from the sensor 71 and an operation signal output from an input device (not illustrated) in response to an operation of an operator are input to the input interface. In the ROM, calculation equations, programs, and data necessary for operation of the gas turbine power plant 1 including the combustion device 3 are stored. For example, numerical values during calculation and data input from the input device are stored in the RAM. The output interface outputs instruction signals to the fuel cut valves 62 and 63, the fuel control valves 64 to 66, and the other actuators such as an inlet guide vane (IGV) provided in the gas turbine power plant 1 in response to instructions from the CPU.The CPU performs control over the fuel cut valves 62 and 63, the fuel control valves 64 to 66, and the like on the basis of the data input through the input interface according to the programs loaded from the ROM.operating and operatingNext, an operation method of the combustion device 3 according to the present embodiment will be described. The operation method described below is automatically executed by the controller 70 in response to the gas turbine load detected by the sensor 71. Alternatively, an operator may execute the operating method through manual actuation during monitoring of the gas turbine load, as applicable. Flow rates of the startup fuel f 1 and the main fuel f 2 are determined based on the gas turbine load such as the output electric power, and the opening degrees of the fuel control valves 64, 65, and 66 are controlled to supply the fuels at the flow rates in response to the gas turbine load.FIG. 3 is an explanatory diagram of the gas turbine combustion device operation method (at startup time) according to the first embodiment. An example of the operation method at a startup time from the ignition of the startup fuel f 1 to the transition to a state of single ignition of the main fuel f 2 will be described with reference to FIG. 3. In FIG. 3, a horizontal axis represents the gas turbine load and the gas turbine load is higher as it is closer to a right side. Moreover, an upper row of FIG. 3 represents changes in flow rates of the startup fuel f 1 and the main fuel f 2, and a lower row thereof represents a change in flow rate of the gaseous fuel supplied to the inner fuel nozzles 21 and the outer fuel nozzles 22 and 23, together with schematic burner diagrams. An inner burner F 1 illustrated in the schematic burner diagrams is an inner circumferential side circular burner configured with the fuel nozzles 21, and an outer burner F 2 is an outer circumferential side annular burner configured with the fuel nozzles 22 and 23.In the present embodiment, the controller 70 or the operator performs the following four procedures (1) to (4) in order to perform operations from ignition to rated load.(1) supplying the startup fuel f 1 to the fuel nozzles 21 (to the inner burner F 1) in a state of not supplying the fuel to the fuel nozzles 22 and 23 (to the outer burner F 2).(2) supplying the main fuel f 2 to the fuel nozzles 22 and 23 in a state of continuing supplying the startup fuel f 1 to the fuel nozzles 21 (the inner burner F 1).(3) starting supplying the main fuel f2 to the fuel nozzles 21 (to the inner burner F1) while continuing supplying the main fuel f2 to the fuel nozzles 22 and 23 (to the outer burner F2) and changing the fuel supplied to the fuel nozzles 21 from the startup fuel f1 to the mixed gaseous fuel of the startup fuel f1 and the main fuel f2.(4) Stopping supplying the startup fuel f 1 to the fuel nozzles 21 (the inner burner F 1) and supplying only the main fuel f 2 to all the fuel nozzles 21 to 23 (both the inner burner F 1 and the outer burner F 2).Fuel supply states in the procedures (1) to (4) correspond to schematic burner diagrams (1) to (4) of the same numbers respectively shown in the lower row of FIG. 3. Operations of the valves in the procedures (1) to (4) will be described.Procedure (1)The starting motor 7 starts rotating a gas turbine rotor, and the controller 70 executes the procedure (1) when the gas turbine load (e.g., the rotational speed of the turbine 4 or the electric power 6 output from the electric generator) increases to a target value L 0 that satisfies an ignition capability condition. In the procedure (1), the controller 70 outputs signals S 2 and S 4 (FIG. 1 ) to the fuel cut valve 62 and the fuel control valve 64, releases the fuel cut valve 62, and opens the fuel control valve 64 to increase the opening degree of the fuel control valve 64, for example, at a fixed increase rate. The startup fuel f 1 is thereby ejected from the fuel nozzles 21 of the inner burner F 1 and ignited, the startup fuel f 1 rises at a predetermined rising rate, and the gas turbine load increases. During this time, the controller 70 closes the fuel cut valve 63 and the fuel control valves 65 and 66. If an operator controls the fuel flow rates, the operator manually operates the opening degrees of the fuel cut valves 62 and 63 and the fuel control valves 64 to 66 using an actuator (not shown) as described above.Procedure (2)When the gas turbine load increases to a first target value L 1 (>L 0), the controller 70 outputs the signals S 2, S 3, S 4, and S 6 (FIG. 1 ) to the fuel cut valves 62 and 63 and the fuel control valves 64 to 66 to execute the procedure (2). In the procedure (2), the controller 70 releases the fuel cut valves 62 and 63 and opens the fuel control valve 66 to increase the opening degree of the fuel control valves 66 at a fixed increase rate, for example, while maintaining the opening degree of the fuel control valves 64. The main fuel f 2 thereby starts to be ejected from the fuel nozzles 22 and 23 of the outer burner F 2 in a state of maintaining an injection amount of the startup fuel f 1 from the fuel nozzles 21 of the inner burner F 1, and the main fuel f 2 is ignited with a flame formed by the startup fuel f 1 as a fire source. The main fuel f2 further increases at a predetermined increase rate and the gas turbine load increases. During this time, the controller 70 closes the fuel control valve 65. If an operator controls the fuel flow rates, the operator manually operates the opening degrees of the fuel cut valves 62 and 63 and the fuel control valves 64 to 66 using the actuator (not shown) as described above.Procedure (3)When the gas turbine load increases to a second target value L 2 (>L 1), the controller 70 outputs the signals S 2 to S 6 (FIG. 1 ) to the fuel cut valves 62 and 63 and the fuel control valves 64 to 66 to execute the procedure (3). In the procedure (3), the controller 70 opens the fuel control valve 65 in a state of releasing the fuel cut valves 62 and 63 and decreases the opening degree of the fuel control valves 64 to zero while increasing the opening degrees of the fuel control valves 65 and 66 at a fixed increase rate, for example. The mixed gaseous fuel of the startup fuel f 1 and the main fuel f 2 starts to be discharged from the fuel nozzles 21 of the inner burner F 1, a main fuel concentration of the mixed gaseous fuel increases, and an injection amount of the main fuel f 2 from the fuel nozzles 22 and 23 of the outer burner F 2 increases. The main fuel f 2 that starts to be ejected from the fuel nozzles 21 is stably burned together with the startup fuel f 1. During this time, the flow rate of the startup fuel f 1 decreases, but the gas turbine load further increases with the increase of the main fuel f 2. If an operator controls the fuel flow rates, the operator manually operates the opening degrees of the fuel cut valves 62 and 63 and the fuel control valves 64 to 66 using the actuator (not shown) as described above.Procedure (4)The gas turbine load is configured to reach a third threshold value L 3 (>L 2) before a supply amount of the main fuel f 2 increases, the opening degree of the fuel control valves 64 falls to zero, and the supply of the startup fuel f 1 stops. In other words, when the gas turbine load increases to the third target value L 3, the controller 70 closes the fuel cut valve 62 and the fuel control valve 64, and stops supplying the startup fuel f 1 to the inner fuel nozzles 21. A burning state thereby transitions to the state of single-ignition of the main fuel f 2 in which only the main fuel f 2 is ejected from all of the inner and outer fuel nozzles 21 to 23. Subsequently, the controller 70 outputs the signals S 3, S 5, and S 6 (FIG. 1 ) to the fuel cut valve 63 and the fuel control valves 65 and 66, and increases the opening degrees of the fuel control valves 65 and 66 (e.g., a total opening area) at a fixed increase rate, for example, in a state of releasing the fuel cut valve 63. as a result, the gas turbine load increases to a rated value LR, and a startup operation is passed. If an operator controls the fuel flow rates, the operator manually operates the opening degrees of the fuel cut valves 62 and 63 and the fuel control valves 64 to 66 using the actuator (not shown) as described above.According to this startup method, it is possible to ensure ignition of the main fuel f 2 using the flame formed by igniting the startup fuel f 1, and to stably and smoothly switch from co-burning the startup fuel f 1 and the main fuel f 2 to single-ignite the main fuel f 2. Note that while in the present embodiment, the case of transitioning the gas turbine load to the rated load in the single-ignition state of the main fuel f 2 is considered as an example, some gas turbine power plants transition the gas turbine load to the rated load in the combustion state of the startup fuel f 1 and the main fuel f 2. In this case, the controller 70 may be configured to execute control to transition the gas turbine load to the rated load by executing the procedure (2) or (3). In this case, it is possible to omit the procedures (3) and (4) or the procedure (4).FIG. 4 is an explanatory diagram of a gas turbine combustion device operation method (at the stop time) according to the first embodiment. An example of the operation method at a stop time from the state of the single ignition of the main fuel f 2 to the quench will be described with reference to FIG. 4. In FIG. 4, a horizontal axis represents the gas turbine load and the gas turbine load is weaker as it is closer to a right side. Moreover, an upper row of FIG. 4 represents changes in the flow rates of the startup fuel f 1 and the main fuel f 2, and its lower row represents a change in the flow rate of the gaseous fuel supplied to the inner fuel nozzles 21 and the outer fuel nozzles 22 and 23, together with schematic burner diagrams.In the present embodiment, the controller 70 or the operator performs the following four procedures (5) to (8) in order to perform operations from the rated load for extinguishing the fuel.(5) lowering the supply amount of the main fuel f 2 to the fuel nozzles 22 and 23 (the outer burner F 2) in a state of supplying only the main fuel f 2 to all the fuel nozzles 21 to 23 (both the inner burner F 1 and the outer burner F 2).(6) starting to supply the startup fuel f 1 to the fuel nozzles 21 (the inner burner F 1), while continuing to supply the main fuel f 2 to the fuel nozzles 22 and 23 (the outer burner F 2), and switching the fuel supplied to the fuel nozzles 21 from the main fuel f 2 to the mixed gaseous fuel of the startup fuel f 1 and the main fuel f 2.(7) reducing the supply amount of the main fuel f 2 to the fuel nozzles 22 and 23 (to the outer burner F 2) in a state of stopping the supply of the main fuel f 2 to the fuel nozzles 21 (to the inner burner F 1) and supplying only the startup fuel f 1 to the fuel nozzles 21 (to the inner burner F 1).(8) Stopping the supply of the main fuel f 2 to the fuel nozzles 22 and 23 (to the outer burner F 2) and decreasing the supply flow rate of the startup fuel f 1 to the fuel nozzles 21 (to the inner burner F 1) to quench the startup fuel f 1 while supplying the startup fuel f 1 only to the fuel nozzles 21 (to the inner burner F 1).Fuel supply states in the procedures (5) to (8) correspond to schematic burner diagrams (5) to (8) of the same numbers shown in the lower row of FIG. 4, respectively. Operations of the valves in the procedures (5) to (8) will be described.Procedure (5)When a stop signal is input from the actuator (not shown) to the controller 70, the controller 70 outputs the signals S 3, S 5, and S 6 (FIG. 1 ) to the fuel cut valve 63 and the fuel control valves 65 and 66 to execute the procedure (5). In the procedure (5), the controller 70 decreases the opening degree of the fuel control valves 66 while increasing the opening degree of the fuel control valves 65 in a state of releasing the fuel cut valve 63 and decreases a total supply flow rate of the main fuel f 2 at a fixed increase rate, for example. During this time, the controller 70 closes the fuel cut valve 62 and the fuel control valve 64. If an operator controls the fuel flow rates, the operator manually operates the opening degrees of the fuel cut valves 62 and 63 and the fuel control valves 64 to 66 using the actuator (not shown) as described above.Procedure (6)When the gas turbine load decreases from the rated load LR to a fourth target value L 4 (<LR), the controller 70 outputs the signals S 2 to S 6 (FIG. 1 ) to the fuel cut valves 62 and 63 and the fuel control valves 64 to 66 to execute the procedure (6). In the procedure (6), the controller 70 opens the fuel control valve 64 while lowering the opening degree of the fuel control valves 66 in a state of releasing the fuel cut valves 62 and 63, and lowers the opening degree of the fuel control valves 65 to zero while increasing the opening degree of the fuel control valves 64 at a fixed increase rate, for example. The mixed gaseous fuel of the startup fuel f 1 and the main fuel f 2 starts to be discharged from the fuel nozzles 21 of the inner burner F 1, a startup fuel concentration of the mixed gaseous fuel increases, and the injection amount of the main fuel f 2 from the fuel nozzles 22 and 23 of the outer burner F 2 decreases, and the load falls. A burning speed falls by starting to discharge the startup fuel f 1 from the fuel nozzles 21, If an operator controls the fuel flow rates, the operator manually operates the opening degrees of the fuel cut valves 62 and 63 and the fuel control valves 64 to 66 using the operating device (not illustrated) as described above.Procedure (7)Further, when the gas turbine load drops to a fifth target value L 5 (<L 4), the controller 70 outputs the signals S 2, S 3, S 4, and S 6 (FIG. 1 ) to the fuel cut valves 62 and 63 and the fuel control valves 64 and 66 to execute the procedure (7). In the procedure (7), the controller 70 decreases the opening degree of the fuel control valves 66 at a fixed increasing rate, for example, while maintaining the opening degree of the fuel control valves 64 in a state of releasing the fuel cut valves 62 and 63. The injection amount of the main fuel f 2 from the fuel nozzles 22 and 23 of the outer burner F 2 thereby decreases, and the gas turbine load falls in a state of maintaining the injection amount of the startup fuel f 1 from the fuel nozzles 21 of the inner burner F 1. During this time, the fuel control valve 65 is closed, the supply of the main fuel f2 to the fuel nozzles 21 of the inner burner F1 is stopped, and the burning state is closer to the single ignition of the startup fuel f1 with a decrease in the supply amount of the main fuel f2. If an operator controls the fuel flow rates, the operator manually operates the opening degrees of the fuel cut valves 62 and 63 and the fuel control valves 64 to 66 using the actuator (not shown) as described above.Procedure (8)The gas turbine load is configured to reach a sixth target value L 6 (<L 5) before the supply amount of the main fuel f 2 is zero. In other words, when the gas turbine load falls to the sixth target value L 6, the controller 70 closes the fuel cut valve 63 and the fuel control valves 65 and 66 to stop supplying the main fuel f 2 to the fuel nozzles 21 to 23. The burning state thereby shifts to the state of single-ignition of the startup fuel f 1 in which only 21 of the startup fuel f 1 is ejected from the inner fuel nozzles. Subsequently, the controller 70 outputs the signals S 2 and S 4 (FIG. 1 ) to the fuel cut valve 62 and the fuel control valve 64, and decreases the opening degree of the fuel control valve 64 to zero at a fixed increase rate, for example, in a state of releasing the fuel cut valve 62. At this time, the burner 8 is extinguished and a stopping operation is passed. If an operator controls the fuel flow rates, the operator manually operates the opening degrees of the fuel cut valves 62 and 63 and the fuel control valves 64 to 66 using the actuator (not shown) as described above.According to this startup method, the combustion state before quenching shifts to the single-ignition state of the startup fuel f 1, and thus it is possible to avoid stagnation of the main fuel f 2 in the downstream turbine 4 while the main fuel f 2 is uncombusted.Advantages andFIG. 5 is an explanatory diagram of advantages of the present invention. In the present embodiment, the startup fuel f 1 such as the natural gas is ignited, and then the main fuel f 2 that is the hydrogen-containing fuel is supplied, thereby making it possible to ensure ignition of the main fuel f 2 to prevent the main fuel f 2 from being discharged from the combustion device 3 while the main fuel f 2 remains uncombusted. A reason for the above will be described with reference to FIG. 5. Figure 5 illustrates an overview of flames formed downstream of the burner. First, the startup fuel f 1 is supplied to the inner fuel nozzles 21, and a central flame 121 of the startup fuel f 1 is formed in a burner center portion downstream of the inner air holes 51. Then, the main fuel f2 is supplied to the outer fuel nozzles 22 and 23, and the gaseous fuel mixed from the main fuel f2 and the compressed air a2 is discharged from the outer air holes 52 and 53 to the combustor 5. The mixed gaseous fuel containing the main fuel f2 and ejected from the outer air holes 52 and 53 to the combustion chamber 5 is reliably ignited by heat of the previously formed central flame 121, and a surrounding flame 122 is formed by the main fuel f2 around the central flame 121. In this way, it is possible to ensure ignition of the main fuel f 2 by the startup fuel f 1 using the previously formed central flame 121, and prevent the main fuel f 2 from being discharged from the combustion device 3 and stagnation in the downstream turbine 4 while the main fuel f 2 remains uncombusted.At this time, the fuel mixer 61 to which the startup fuel f 1 and / or the main fuel f 2 can be supplied is connected to the inner fuel nozzles 21, thereby making it possible to inject the startup fuel f 1, the main fuel f 2, and the gaseous fuel mixed from the startup fuel f 1 and the main fuel f 2 from the same fuel nozzles 21 (the same injection ports). Thereby, it is possible to further inject the main fuel f 2 from the fuel nozzles 21 (the injection ports) used to inject the startup fuel f 1 if the startup fuel f 1 is injected and ignited and then a burning operation shifts to an operation of single-ignition the main fuel f 2. It is possible to further supply the main fuel f 2 to a central flame formation zone 121 by the startup fuel f 1 and maintain dispersibility of the gaseous fuel suitably even after the transition to the single-ignition state of the main fuel f 2.As described so far, according to the present embodiment, it is possible to stably ignite the hydrogen-containing fuel using the gaseous fuel containing no hydrogen and improve the dispersibility of the hydrogen-containing fuel. Since a gas turbine power generation plant can be stably used by the hydrogen-containing fuel, it is possible to contribute to weakening of the heating of the earth. Moreover, since combustion stability can be secured using a by-product gas generated in an ironhut or an oil refinery as the main fuel f 2, it is possible to contribute to utilization of raw materials and reduction of power generation cost.Moreover, since the supply of the main fuel f 2 is stopped before quenching and the combustion state shifts to the single-ignition state of the startup fuel f 1, it is possible to prevent ignition before the stop of the supply of the main fuel f 2 and prevent stagnation of the main fuel f 2 in the downstream turbine 4 while the main fuel f 2 remains uncombusted even in the stopping operation.Second EmbodimentFIG. 6 is a schematic configuration diagram of a gas turbine power plant configured with a gas turbine combustor according to a second embodiment. FIG. 6 corresponds to FIG. 1 according to the first embodiment. In FIG. 6, similar elements to those in the first embodiment are denoted by the same reference numerals as in FIG. 1, and description thereof is omitted. The present embodiment is different from the first embodiment in that injection ports of inner fuel nozzles 21A and outer fuel nozzles 22A are open to inner wall surfaces of air holes of the air hole plate 20.In the present embodiment, injection ports 701 of the fuel nozzles 21A are open to inner walls of the air holes 51, and injection ports 702 and 703 of the fuel nozzles 22A are open to inner walls of the air holes 52 and 53. The communication passage 68 is connected to the fuel nozzles 21A, and the main fuel pipe 60 is connected to the fuel nozzles 22A. The other configuration is similar to the first embodiment.Even with such a lean combustion type burner configuration, by appropriately controlling the fuels, it is possible to obtain similar advantages as in the first embodiment.Third Embodiment- Configuration ConfigurationsFIG. 7 is a schematic configuration diagram of a gas turbine power plant configured with a gas turbine combustor according to a third embodiment of the present invention. FIG. 8 illustrates a burner provided in the gas turbine combustor according to the third embodiment of the present invention, the burner being viewed from a combustor. FIGS. 7 and 8 correspond to FIGS. 1 and 2 of the first embodiment. In FIGS. 7 and 8, elements similar to those of the first embodiment are denoted by the same reference numerals as in FIG. 1, and description thereof is omitted. The present embodiment is different from the first embodiment in that the outer fuel nozzles 22 and 23 are divided into a plurality (three in the present embodiment) of nozzle groups, and the main fuel pipe 60 is branched into a plurality (three in the present embodiment) of pipes connected to the corresponding nozzle groups.In the present embodiment, the outer fuel nozzles 22 and 23 and the air holes 52 and 53 are defined into a plurality of zones X 1 to X 3 in a circumferential direction, and a first nozzle group belongs to the zone X 1, a second nozzle group belongs to the zone X 2, and a third nozzle group belongs to the zone X 3. Moreover, in the present embodiment, the fuel cavity 26 distributing the main fuel f 2 to the outer fuel nozzles 22 and 23 is also divided into a plurality (three in the present embodiment) of fuel cavities 26 ato 26 c. The fuel cavity 26a is connected to the fuel nozzles 22 and 23 configuring the first nozzle group. The fuel cavity 26 bis connected to the fuel nozzles 22 and 23 configuring the second nozzle group. The fuel cavity 26 cis connected to the fuel nozzles 22 and 23 configuring the third nozzle group.In addition, in the present embodiment, the main fuel line 60 branches into a plurality (three in the present embodiment) of branch lines 60 ato 60 c. The branch line 60a is connected to the fuel cavity 26a, the branch line 60b is connected to the fuel cavity 26b, and the branch line 60c is connected to the fuel cavity 26c. No fuel control valve is provided in the main fuel line 60 (the portion before branching of the branch lines 60 ato 60 c). In the present embodiment, a fuel control valve 66a is provided in the branch line 60a, a fuel control valve 66b is provided in the branch line 60b, and a fuel control valve 66c is provided in the branch line 60c. The fuel control valves 66a to 66c are identical to the fuel control valve 66 according to the first embodiment.The present embodiment is similar in further respects to the first embodiment. Note that a burner configured such that the injection ports of the fuel nozzles are open to the inner wall surfaces of the air holes is also applicable to the present embodiment similarly to the second embodiment. The number of nozzle groups is not limited to three, and may be two or more. For example, the number of nozzle groups may be equal to or greater than four, or may be two. Increasing the number of nozzle groups enables the combustion device 3 to be compatible with a high-capacity gas turbine and improving the operation controllability. Moreover, the nozzle groups into which the fuel nozzles 22 and 23 are divided may be arranged not in the circumferential direction but in a radial direction (i.e., as annular rows).operating and operatingFIG. 9 is an explanatory diagram of a combustion device operation method (at startup time) according to the third embodiment. FIG. 9 corresponds to FIG. 3 according to the first embodiment. An example of the operation method at the startup time from the ignition of the startup fuel f 1 to the transition to the single-ignition state of the main fuel f 2 will be described with reference to FIG. 9. In FIG. 9, a horizontal axis represents the gas turbine load and the gas turbine load is higher as it is closer to a right side. Moreover, an upper row of FIG. 9 represents changes in the flow rates of the startup fuel f 1 and the main fuel f 2, and its lower row represents a change in the flow rate of the gaseous fuel supplied to the inner fuel nozzles 21 and the nozzle groups of the outer fuel nozzles 22 and 23, together with schematic burner diagrams. The inner burner F 1 illustrated in the schematic burner diagrams is the inner circumferential circular burner configured with the fuel nozzles 21. An outer burner F 2 ais a fan-shaped burner configured with the fuel nozzles 22 and 23 in the first nozzle group. An outer burner F 2 bis a fan-shaped burner configured with the fuel nozzles 22 and 23 in the second nozzle group, and an outer burner F 2 cis a fan-shaped burner configured with the fuel nozzles 22 and 23 in the third nozzle group.Startup procedures according to the present embodiment are similar to those according to the first embodiment except that the procedure (2) is divided into three stages of the procedures (2a) to (2c) in the four procedures (1) to (4) described in the first embodiment. In the present embodiment, the procedures (1), (3), and (4) are similar to those according to the first embodiment, and therefore, description thereof is omitted, and the procedures (2a) to (2c) will be described below. After completion of the procedure (1), the following procedures (2a) to (2c) are carried out in sequence. After completion of the procedure (2c), the procedures (3) and (4) are executed similarly to the first embodiment. Note that while in the present embodiment the three fuel control valves 66 ato 66 care provided for the outer burners F 2 ato F 2 c, the fuel control valves 66 ato 66 care controlled in the procedures (3) and (4), respectively.Procedure (2a)When the gas turbine load increases to a first target value L 1 a(>L 0) after execution of the procedure (1), the controller 70 outputs the signals S 2, S 3, S 4, and S 6 a(FIG. 7 ) to the fuel cut valves 62 and 63 and the fuel control valves 64 and 66 ato execute the procedure (2 a). In the procedure (2a), the controller 70 releases the fuel cut valves 62 and 63 and opens the fuel control valve 66a to increase the opening degree of the fuel control valves 66a at a fixed increase rate, for example, while maintaining the opening degree of the fuel control valves 64. The main fuel f 2 thereby starts to be ejected from the fuel nozzles 22 and 23 of the outer burner F 2 ain the state of maintaining the injection amount of the startup fuel f 1 from the fuel nozzles 21 of the inner burner F 1, and the main fuel f 2 is ignited with the flame formed by the startup fuel f 1 as a source of the fire. The main fuel f2 further increases at a predetermined increase rate and the gas turbine load increases. During this time, the controller 70 closes the fuel control valves 65, 66b and 66c. If an operator controls the fuel flow rates, the operator manually operates the opening degrees of the fuel cut valves 62 and 63 and the fuel control valves 64, 65, and 66a to 66c using the actuator (not shown) as described above.Procedure (2b)When the gas turbine load increases to a target value L 1 b(>L 1 a), the controller 70 outputs the signals S 2, S 3, S 4, S 6 a, and S 6B (FIG. 7 ) to the fuel cut valves 62 and 63 and the fuel control valves 64, 66 a, and 66 bto execute the procedure (2 b). In the procedure (2b), the controller 70 releases the fuel cut valves 62 and 63 and opens the fuel control valve 66b again to increase the opening degree of the fuel control valves 66b at a fixed increase rate, for example, while maintaining the opening degrees of the fuel control valves 64 and 66a. Thereby, the main fuel f 2 starting to be ejected from the fuel nozzles 22 and 23 of the outer burner F 2 bis smoothly ignited, a supply zone of the main fuel f 2 expands, the supply amount of the main fuel f 2 further increases, and the gas turbine load increases. During this time, the controller 70 closes the fuel control valves 65 and 66c. If an operator controls the fuel flow rates, the operator manually operates the opening degrees of the fuel cut valves 62 and 63 and the fuel control valves 64, 65, and 66a to 66c using the actuator (not shown) as described above.Procedure (2c)When the gas turbine load increases to a target value L 1 c(L 1 b<L 1 c<L 2), the controller 70 outputs the signals S 2, S 3, S 4, and S 6 ato S 6 c(FIG. 7 ) to the fuel cut valves 62 and 63 and the fuel control valves 64 and 66 ato 66 cto execute the procedure (2 c). In the procedure (2c), the controller 70 releases the fuel cut valves 62 and 63 and opens the fuel control valve 66c again to increase the opening degree of the fuel control valves 66c at a fixed increase rate, for example, while maintaining the opening degrees of the fuel control valves 64, 66a and 66b. The main fuel f2 starting to be ejected from the fuel nozzles 22 and 23 of the outer burner F2c is thereby gently ignited, the supply zone of the main fuel f2 continues to increase, the supply amount of the main fuel f2 continues to increase, and the gas turbine load increases. During this time, the controller 70 closes the fuel control valve 65. If an operator controls the fuel flow rates, the operator manually operates the opening degrees of the fuel cut valves 62 and 63 and the fuel control valves 64, 65, and 66a to 66c using the actuator (not shown) as described above.FIG. 10 is an explanatory diagram of a gas turbine combustion device operation method (at the stop time) according to the third embodiment. FIG. 10 corresponds to FIG. 4 according to the first embodiment. An example of the operation method at the stop time from the state of the single ignition of the main fuel f 2 to the quench will be described with reference to FIG. 10. In FIG. 10, a horizontal axis represents the gas turbine load and the gas turbine load is weaker as it is closer to a right side. Moreover, an upper row of FIG. 10 represents changes in the flow rates of the startup fuel f 1 and the main fuel f 2, and its lower row represents a change in the flow rate of the gaseous fuel supplied to the inner fuel nozzles 21 and the nozzle groups of the outer fuel nozzles 22 and 23, together with schematic burner diagrams.The stopping procedures according to the present embodiment are similar to those according to the first embodiment except that the procedure (7) is divided into three stages of the procedures (7a), (7b) and (7c) in the four procedures (5) to (8) described in the first embodiment. In the present embodiment, the procedures (5), (6), and (8) are similar to those according to the first embodiment, and therefore description thereof is omitted, and the procedures (7c), (7b), and (7a) will be described below. After completion of the procedures (5) and (6), the following procedures (7c), (7b) and (7a) are carried out in sequence. After completion of the procedure (7a), the procedure (8) according to the first embodiment is executed. Note that while in the present embodiment the three fuel control valves 66 ato 66 care provided for the outer burners F 2 ato F 2 c, the fuel control valves 66 ato 66 care similarly controlled in the procedures (5) and (6).Procedure (7c)When the gas turbine load drops to a fifth target value L 5 c(<L 4) after execution of the procedure (6), the controller 70 outputs the signals S 2, S 3, S 4, and S 6 ato S 6 c(FIG. 7 ) to the fuel cut valves 62 and 63 and the fuel control valves 64 and 66 ato 66 cto execute the procedure (7 c). In the procedure (7c), the controller 70 decreases the opening degree of the fuel control valves 66c to zero at a fixed increasing rate, for example, while maintaining the opening degrees of the fuel control valves 64, 66a and 66b in the state of releasing the fuel cut valves 62 and 63. Thereby, the injection amount of the main fuel f 2 from the outer burner F 2 cis decreased, and the gas turbine load drops in a state of maintaining the injection amount of the startup fuel f 1 from the inner burner F 1 and the injection amounts of the main fuel f 2 from the outer burners F 2 aand F 2 b. During this time, the fuel control valve 65 is closed and the supply of the main fuel f2 to the fuel nozzles 21 of the inner burner F1 is stopped. If an operator controls the fuel flow rates, the operator manually operates the opening degrees of the fuel cut valves 62 and 63 and the fuel control valves 64 to 66 using the actuator (not shown) as described above.Procedure (7b)When the gas turbine load falls to a target value L 5 b(<L 5 c), the controller 70 outputs the signals S 2, S 3, S 4, S 6 a, and S 6B (FIG. 7 ) to the fuel cut valves 62 and 63 and the fuel control valves 64, 66 a, and 66 bto execute the procedure (7 b). In the procedure (7b), the controller 70 decreases the opening degree of the fuel control valves 66b to zero at a fixed increasing rate, for example, while maintaining the opening degrees of the fuel control valves 64 and 66a in the state of releasing the fuel cut valves 62 and 63. Thereby, the injection amount of the main fuel f 2 from the outer burner F 2 bsides, and the gas turbine load further falls in a state of maintaining the injection amount of the startup fuel f 1 from the inner burner F 1 and the injection amount of the main fuel f 2 from the outer burner F 2 a. During this time, the controller 70 closes the fuel control valves 65 and 66c. If an operator controls the fuel flow rates, the operator manually operates the opening degrees of the fuel cut valves 62 and 63 and the fuel control valves 64 to 66 using the actuator (not shown) as described above.Procedure (7a)When the gas turbine load falls to a target value L 5 a(L 6<L 5 a<L 5 b), the controller 70 outputs the signals S 2, S 3, S 4, and S 6 a(FIG. 7 ) to the fuel cut valves 62 and 63 and the fuel control valves 64 and 66 ato execute the procedure (7 a). In the procedure (7a), the controller 70 decreases the opening degree of the fuel control valves 66a to zero at a fixed increase rate, for example, while maintaining the opening degree of the fuel control valves 64 in the state of releasing the fuel cut valves 62 and 63. Thereby, the injection amount of the main fuel f 2 from the outer burner F 2 adeceeds, and the gas turbine load further falls in a state of maintaining the injection amount of the startup fuel f 1 from the inner burner F 1. During this time, the controller 70 closes the fuel control valves 65, 66b and 66c. If an operator controls the fuel flow rates, the operator manually operates the opening degrees of the fuel cut valves 62 and 63 and the fuel control valves 64 to 66 using the actuator (not shown) as described above.Advantages andThe present embodiment can achieve advantages similar to those of the first embodiment. Moreover, dividing the outer fuel nozzles 22 and 23 into the plurality of nozzle groups and executing the starting and stopping of the supply of the main fuel f 2 per nozzle group to successively perform the ignition of the main fuel f 2 and the like further makes it possible to ensure suppression of the emissions of the unburned main fuel f 2.Fourth Embodiment- Configuration ConfigurationsFIG. 11 is a schematic configuration diagram of a gas turbine power plant configured with a gas turbine combustion apparatus according to a fourth embodiment of the present invention. FIG. 12 illustrates a burner provided in the gas turbine combustion apparatus according to the fourth embodiment of the present invention, the burner being viewed from a combustor. FIGS. 11 and 12 correspond to FIGS. 1 and 2 of the first embodiment. In FIGS. 11 and 12, elements similar to those of the first embodiment are denoted by the same reference numerals as in FIGS. 1 and 2, and description thereof is omitted. The present embodiment is different from the first embodiment in that the combustion device 3 is configured with a multiple burner configured with multiple burners.The combustion device 3 according to the present embodiment is configured with a pilot burner 31 and a plurality of (six in the present embodiment) main burners 32, and the pilot burner 31 and the main burners 32 are arranged such that the vicinity of a pilot burner 31 arranged at a center is surrounded by the plurality of main burners 32. In the present embodiment, a case of applying a burner structure according to the first embodiment to each of the pilot burner 31 and the main burners 32 is exemplified. Note that the burner 8 according to the first, second, or third embodiment may be applied to each of the pilot burner 31 and the main burner 32, as applicable. For example, the burner 8 according to any one of the first to third embodiments may be uniformly used as each of the pilot burner 31 and the main burners 32, or a mixture of the burners 8 according to the first to third embodiments may be used as the pilot burner 31 and the main burners 32, as applicable. The air hole plate 20 may be shared between the pilot burner 31 and the plurality of main burners 32 (the air holes 51 to 53 of each burner may be formed in one air hole plate 20).With respect to the fuel supply system 200, the communication passage 68 may branch into a plurality (three in the present embodiment) of branch pipes 68A to 68C. The branch pipe 68A is connected to the inner fuel nozzles 21 (the fuel cavity 25) of the pilot burner 31. The branch line 68B is connected to the inner fuel nozzles 21 (the fuel cavities 25) of half of the main burners 32, and the branch line 68C is connected to the inner fuel nozzles 21 (the fuel cavities 25) of the remaining main burners 32. Moreover, a fuel control valve 65A is provided in the branch line 68A, a fuel control valve 65B is provided in the branch line 68B, and a fuel control valve 65C is provided in the branch line 68C. The fuel control valves 65A to 65C are identical to, for example, the fuel control valve 65.In addition, in the present embodiment, the main fuel line 60 branches into a plurality (three in the present embodiment) of branch lines 60A to 60C. The branch line 60A is connected to the outer fuel nozzles 22 and 23 (the fuel cavity 26) of the pilot burner 31. The branch line 60B is connected to the outer fuel nozzles 22 and 23 (the fuel cavities 26) of half of the main burners 32, and the branch line 60C is connected to the outer fuel nozzles 22 and 23 (the fuel cavities 26) of the remaining main burners 32. No fuel control valve is provided in the main fuel line 60 (the portion before branching of the branch lines 60A to 60C). In the present embodiment, a fuel control valve 66A is provided in the branch line 60A, a fuel control valve 66B is provided in the branch line 60B, and a fuel control valve 66C is provided in the branch line 60C. The fuel control valves 66A to 66C are identical to the fuel control valve 66 according to the first embodiment.The present embodiment is otherwise similar to the first, second or third embodiment.operating and operatingFIG. 13 is an explanatory diagram of a gas turbine combustion device operation method (at startup time) according to the fourth embodiment. FIG. 13 corresponds to FIG. 3 according to the first embodiment. An example of the operation method at the startup time from the ignition of the startup fuel f 1 to the transition to the single-ignition state of the main fuel f 2 will be described with reference to FIG. 13. In FIG. 13, a horizontal axis represents the gas turbine load and the gas turbine load is higher as it is closer to a right side. Moreover, an upper row of FIG. 13 represents changes in the flow rates of the startup fuel f 1 and the main fuel f 2, and its lower row represents a change in the flow rate of the gaseous fuel supplied to the inner fuel nozzles 21 and the outer fuel nozzles 22 and 23, the pilot burner 31, and the main burner 32, together with schematic burner diagrams. An inner burner F 11 illustrated in the schematic burner diagrams is an inner burner (corresponding to the fuel nozzles 21) of the pilot burner 31 and an outer burner F 12 is an outer burner (corresponding to the fuel nozzles 22 and 23) of the pilot burner 31. In addition, with respect to the main burners 32, it is assumed that three alternate main burners 32 in the circumferential direction belong to a first group and that the remaining three main burners 32 belong to a second group. An inner burner F 21 is an inner burner (corresponding to the fuel nozzles 21) of the main burners 32 in the first group, and an outer burner F 22 is an outer burner (corresponding to the fuel nozzles 22 and 23) of the main burners 32 in the first group. An inner burner F 31 is an inner burner (corresponding to the fuel nozzles 21) of the main burners 32 in the second group, and an outer burner F 32 is an outer burner (corresponding to the fuel nozzles 22 and 23) of the main burners 32 in the second group.Startup procedures according to the present embodiment are similar to those according to the first embodiment except that the procedure (1) is divided into two stages of the procedures (1A) and (1B) in the four procedures (1) to (4) described in the first embodiment. Procedures (1A) and (1B) will be described below. After completion of the following procedures (1A) and (1B), the procedures (2) to (4) according to the first embodiment are executed. Note that while in the present embodiment the three fuel control valves 65A to 65C are provided for the startup fuel f 1, the fuel control valves 65A to 65C are similarly controlled in the procedures (2) to (4). Also, while the three fuel control valves 66A to 66C are provided for the main fuel f2, the fuel control valves 66A to 66C are similarly controlled in the procedures (2) to (4).Procedure (1A)The starting motor 7 starts rotating the gas turbine rotor, and the controller 70 executes the procedure (1A) when the gas turbine load increases to a target value L 0A satisfying an ignition capability condition. In the procedure (1A), the controller 70 outputs the signals S 2, S 4, S 5A, and S 5B (FIG. 11 ) to the fuel cut valve 62 and the fuel control valves 64, 65A, and 65B, releases the fuel cut valve 62, and opens the fuel control valves 64, 65A, and 65B to increase the opening degrees of the fuel control valves 64, 65A, and 65B at a fixed increase rate, for example. The startup fuel f 1 is thereby discharged and ignited from the inner burners F 11 and F 21, the startup fuel f 1 rises at a predetermined rising rate, and the gas turbine load increases. During this time, the controller 70 closes the fuel cut valve 63 and the fuel control valves 65, 65C and 66A to 66C. If an operator controls the fuel flow rates, the operator manually operates the opening degrees of the fuel cut valves 62 and 63 and the fuel control valves 64, 65, 65A to 65C and 66A to 66C using the actuator (not shown) as described above.Procedure (1B)When the gas turbine load increases to a target value L 0B (L 0A<L 0B<L 1), the controller 70 executes the procedure (1B). In the procedure (1B), the controller 70 outputs the signals S 2, S 4, and S 5A to S 5C (FIG. 11 ) to the fuel cut valve 62 and the fuel control valves 64 and 65A to 65C, re-opens the fuel control valve 65C, and increases the opening degrees of the fuel control valves 64 and 65A to 65C at a fixed increase rate, for example. The startup fuel f 1 is thereby discharged from the inner burners F 11 to F 31, the startup fuel f 1 rises at a predetermined rising rate, and the gas turbine load increases. During this time, the controller 70 closes the fuel cut valve 63 and the fuel control valves 65 and 66A to 66C. If an operator controls the fuel flow rates, the operator manually operates the opening degrees of the fuel cut valves 62 and 63 and the fuel control valves 64, 65, 65A to 65C and 66A to 66C using the actuator (not shown) as described above.FIG. 14 is an explanatory diagram of a combustion device operation method (at the stop time) according to the fourth embodiment. FIG. 14 corresponds to FIG. 4 according to the first embodiment. An example of the operation method at the stop time from the rated load to the cancellation will be described with reference to FIG. 14. In FIG. 14, a horizontal axis represents the gas turbine load and the gas turbine load is weaker as it is closer to a right side. Moreover, an upper row of FIG. 14 represents changes in the flow rates of the startup fuel f 1 and the main fuel f 2, and its lower row represents a change in the flow rate of the gaseous fuel supplied to the inner fuel nozzles 21 and the outer fuel nozzles 22 and 23, the pilot burner 31, and the main burner 32, together with schematic burner diagrams.The stopping procedures according to the present embodiment are similar to those according to the first embodiment except that the procedure (8) in the four procedures (5) to (8) described in the first embodiment is divided into two stages of the procedures (8A) and (8B). Procedures (8A) and (8B) will be described below. Similarly to the first embodiment, after execution of the procedures (5) to (7), the following procedures (8A) and (8B) are executed. Note that while the three fuel control valves 65A to 65C are provided for the startup fuel f 1 in the present embodiment, the fuel control valves 65A to 65C are controlled in the procedures (5) to (7), respectively. Also, while the three fuel control valves 66A to 66C are provided for the main fuel f2, the fuel control valves 66A to 66C are controlled in the procedures (5) to (7), respectively.Procedure (8A)When the gas turbine load drops to a sixth target value L 6A (<L 5) after execution of the procedure (7), the controller 70 outputs the signals S 2, S 4, and S 5A to S 5C (FIG. 11 ) to the fuel cut valve 62 and the fuel control valves 64 and 65A to 65C to execute the procedure (8A). In the procedure (8A), the controller 70 decreases the opening degrees of the fuel control valves 64 and 65A to 65C at a fixed increase rate in the release state of the fuel cut valve 62, for example. During this time, the fuel cut valve 63 and the fuel control valves 65 and 66A to 66C are closed, and the combustion state is the single-ignition state of the startup fuel f 1. If an operator controls the fuel flow rates, the operator manually operates the opening degrees of the fuel cut valves 62 and 63 and the fuel control valves 64, 65, 65A to 65C and 66A to 66C using the actuator (not shown) as described above.Procedure (8B)When the gas turbine load falls to a target value L 6B (<L 6A), the controller 70 outputs the signals S 2, S 4, S 5A, and S 5B (FIG. 11 ) to the fuel cut valve 62 and the fuel control valves 64, 65A, and 65B to execute the procedure (8B). In the procedure (8B), the controller 70 decreases the opening degrees of the fuel control valves 64, 65A, and 65B to zero at a fixed increase rate in the state of releasing the fuel cut valve 62, for example. In the course of this, the combustion device 3 is extinguished and the stopping operation is over. During this time, the fuel cut valve 63 and the fuel control valves 65, 65C and 66A to 66C are closed, and the number of injection burners for the startup fuel f1 is reduced to two, i.e., the injection burners for the startup fuel f1 are the inner burners F11 and F21. If an operator controls the fuel flow rates, the operator manually operates the opening degrees of the fuel cut valves 62 and 63 and the fuel control valves 64, 65, 65A to 65C and 66A to 66C using the actuator (not shown) as described above.Advantages andConfiguring the multiple burner by applying a burner configuration according to the first to third embodiments to the pilot burner 31 and the main burners 32 as applicable, respectively, enables the fourth embodiment to achieve advantages similar to those in the foregoing embodiments or advantages as a combination of the advantages of these foregoing embodiments even when the combustion apparatus 3 is used for a high capacity gas turbine.

Claims

A gas turbine combustor comprising: a burner (8) including: a startup fuel line (57) in which startup fuel circulates; a first main fuel line (59) in which main fuel circulates; a second main fuel line (60) in which main fuel circulates; a fuel mixer (61) to which the startup fuel line (57) and the first main fuel line (59) are connected; an inner fuel nozzle (21) to which the fuel mixer (61) is connected; a plurality of outer fuel nozzles (22, 23) to which the second main fuel line (60) is connected; a startup fuel control valve (64) provided in the startup fuel line (57); a first fuel control valve (65) provided in the first main fuel line (59); a second fuel control valve (66) provided in said second main fuel line (60); and a controller (70) configured to control the startup fuel control valve (64), the first fuel control valve (65), and the second fuel control valve (66), wherein the controller (70) performs procedures including: (1) increasing an opening degree of the startup fuel control valve (64) to supply the startup fuel to the inner fuel nozzle (21), (2) increasing an opening degree of the second fuel control valve (66) to supply the main fuel to a plurality of outer fuel nozzles (22, 23) when a gas turbine load increases to a first target value, and (3) increasing an opening degree of the first fuel control valve (65) to supply a mixed gaseous fuel of the startup fuel and the main fuel to the inner fuel nozzle (21) when the gas turbine load further increases to a second target value.The gas turbine combustion apparatus according to claim 1, wherein the controller (70) executes procedures including: (4) closing the first fuel control valve (65) to stop supplying the main fuel to the inner fuel nozzle (21) and decreasing the opening degree of the second fuel control valve (66) when the opening degree of the second fuel control valve (66) is decreased and the gas turbine load decreases to a third target value, and (5) closing the second fuel control valve (66) to transition to a state of single ignition of the startup fuel, and then decreasing the opening degree of the startup fuel control valve (64) to zero to quench the startup fuel when the gas turbine load further decreases to a fourth target value.The gas turbine combustion apparatus according to claim 1, wherein the controller (70) executes procedures including: (4) closing the startup fuel control valve (64) to stop supplying the startup fuel to the inner fuel nozzle (21), and transitioning to a single-ignition state of the main fuel, the single-ignition state being a state in which only the main fuel is ejected from all of the plurality of outer fuel nozzles (22, 23) and the inner fuel nozzle (21) when the gas turbine load further increases to a third target value.The gas turbine combustion apparatus according to claim 3, wherein the controller (70) performs procedures including: (5) decreasing the opening degree of the second fuel control valve (66); (6) increasing the opening degree of the startup fuel control valve (64) to supply the gaseous fuel mixed from the startup fuel and the main fuel to the inner fuel nozzle (21) when the gas turbine load drops to a fourth target value; (7) closing the first fuel control valve (65) to stop supplying the main fuel to the inner fuel nozzle (21), and decreasing the opening degree of the second fuel control valve (66) when the gas turbine load further drops to a fifth target value; and (8) closing the second fuel control valve (66) to transition to a state of single ignition of the startup fuel, and subsequently reducing the opening degree of the startup fuel control valve (64) to zero to quench the startup fuel when the gas turbine load further drops to a sixth target value.The gas turbine combustor according to claim 1, wherein the plurality of outer fuel nozzles (22, 23) are divided into a plurality of nozzle groups, the second main fuel pipe (60) branches into a plurality of branch pipes, and the plurality of branch pipes are each connected to a corresponding nozzle group.The gas turbine combustor according to claim 1, further comprising: a plurality of burners (8).The gas turbine combustor according to claim 1, further comprising: a cylindrical liner forming a combustor (5); and an air hole plate disposed at an inlet port of the liner and including a plurality of air holes (52, 53) that supply compressed air to the combustor (5), wherein the inner fuel nozzle (21) and the plurality of outer fuel nozzles (22, 23) have injection ports oriented to the corresponding air holes (52, 53) and disposed opposite to the combustor (5) above the air hole plate, and the inner fuel nozzle (21) and the plurality of outer fuel nozzles (22, 23) are concentrically disposed.The gas turbine combustion apparatus according to claim 1, further comprising: a cylindrical liner forming a combustor (5); and an air hole plate disposed at an inlet port of the liner and including a plurality of air holes (52, 53) that guide compressed air to the combustor (5), wherein injection ports of the inner fuel nozzle (21) and the outer fuel nozzles (22, 23) are open to inner wall surfaces of the air holes (52, 53).The gas turbine combustor of claim 1, wherein the start-up fuel is either natural gas or petroleum gas and the main fuel is a hydrogen-containing fuel.A gas turbine combustor operating method using a gas turbine combustor, the gas turbine combustor comprising: a burner (8) including: a startup fuel line (57) in which startup fuel circulates; a first main fuel line (59) in which main fuel circulates; a second main fuel line (60) in which main fuel circulates; a fuel mixer (61) to which the startup fuel line (57) and the first main fuel line (59) are connected; an inner fuel nozzle (21) to which the fuel mixer (61) is connected; a plurality of outer fuel nozzles (22, 23) to which the second main fuel line (60) is connected; a startup fuel control valve (64) provided in the startup fuel line (57); a first fuel control valve (65) provided in the first main fuel line (59); and a second fuel control valve (66) provided in the second main fuel line (60), the method comprising: increasing an opening degree of the startup fuel control valve (64) to supply the startup fuel to the inner fuel nozzle (21); increasing an opening degree of the second fuel control valve (66) to supply the main fuel to a plurality of outer fuel nozzles (22, 23) when a gas turbine load increases to a first target value; and increasing an opening degree of the first fuel control valve (65) to supply a mixed gaseous fuel of the startup fuel and the main fuel to the inner fuel nozzle (21) when the gas turbine load further increases to a second target value.The gas turbine combustor operating method according to claim 10, further comprising: closing the first fuel control valve (65) to stop supplying the main fuel to the inner fuel nozzle (21) and decreasing the opening degree of the second fuel control valve (66) when the opening degree of the second fuel control valve (66) is decreased and the gas turbine load decreases to a third target value; and closing the second fuel control valve (66) to transition to a single ignition state of the startup fuel, and subsequently decreasing the opening degree of the startup fuel control valve (64) to zero to quench the startup fuel when the gas turbine load further decreases to a fourth target value.The gas turbine combustion device operating method according to claim 10, further comprising: closing the startup fuel control valve (64) to stop supplying the startup fuel to the inner fuel nozzle (21), and transitioning to a single-ignition state of the main fuel, wherein the single-ignition state is a state in which only the main fuel is ejected from all of the plurality of outer fuel nozzles (22, 23) and inner fuel nozzle (21) when the gas turbine load further increases to a third target value.The gas turbine combustor operating method according to claim 12, further comprising: decreasing the opening degree of the second fuel control valve (66); increasing the opening degree of the startup fuel control valve (64) to supply the gaseous fuel mixed from the startup fuel and the main fuel to the inner fuel nozzle (21) when the gas turbine load decreases to a fourth target value; closing the first fuel control valve (65) to stop supplying the main fuel to the inner fuel nozzle (21), and decreasing the opening degree of the second fuel control valve (66) when the gas turbine load further decreases to a fifth target value; and closing the second fuel control valve (66) to transition to a single-ignition state of the startup fuel, and subsequently reducing the opening degree of the startup fuel control valve (64) to zero to quench the startup fuel when the gas turbine load further drops to a sixth target value.

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