阅读说明：本技术 燃气轮机燃烧器以及其运转方法 (Gas turbine combustor and method for operating same ) 是由 浅井智广 吉田正平 平田义隆 林明典 穐山恭大 松原庆典 于 2020-09-30 设计创作，主要内容包括：本发明提供一种燃气轮机燃烧器及其运转方法,利用不含氢的气体燃料而能够稳定地将含氢燃料点火、且提高含氢燃料的分散性。燃气轮机燃烧器具备燃烧嘴,构成为包括供起动用燃料流通的起动用燃料配管、供主燃料流通的第一主燃料配管、供主燃料流通的第二主燃料配管、上述起动用燃料配管以及上述第一主燃料配管连接的燃料混合器、上述燃料混合器连接的内周燃料喷嘴、上述第二主燃料配管连接的多个外周燃料喷嘴、设置于上述起动用燃料配管的起动用燃料控制阀、设置于上述第一主燃料配管的第一燃料控制阀、设置于上述第二主燃料配管的第二燃料控制阀。(The invention provides a gas turbine combustor and an operation method thereof, which can stably ignite hydrogen-containing fuel and improve the dispersibility of the hydrogen-containing fuel by using hydrogen-free gas fuel. The gas turbine combustor includes a combustion nozzle including a starting fuel pipe through which a starting fuel flows, a first main fuel pipe through which a main fuel flows, a second main fuel pipe through which the main fuel flows, a fuel mixer to which the starting fuel pipe and the first main fuel pipe are connected, an inner peripheral fuel nozzle to which the fuel mixer is connected, a plurality of outer peripheral fuel nozzles to which the second main fuel pipe is connected, a starting fuel control valve provided in the starting fuel pipe, a first fuel control valve provided in the first main fuel pipe, and a second fuel control valve provided in the second main fuel pipe.)

1. A gas turbine combustor characterized by,

is provided with a combustion nozzle, a burner nozzle,

the gas turbine combustor is configured to include:

a starting fuel pipe through which a starting fuel flows;

a first main fuel pipe through which a main fuel flows;

a second main fuel pipe through which the main fuel flows;

a fuel mixer to which the starting fuel pipe and the first main fuel pipe are connected;

an inner peripheral fuel nozzle to which the fuel mixer is connected;

a plurality of outer peripheral fuel nozzles connected to the second main fuel pipe;

a starting fuel control valve provided in the starting fuel pipe;

a first fuel control valve provided in the first main fuel pipe; and

and a second fuel control valve provided in the second main fuel pipe.

2. The gas turbine combustor of claim 1,

a controller for controlling the starting fuel control valve, the first fuel control valve, and the second fuel control valve,

the controller executes the following steps:

(1) increasing the opening degree of the starting fuel control valve and supplying the starting fuel to the inner peripheral fuel nozzle;

(2) increasing the opening of the second fuel control valve and supplying the main fuel to the plurality of outer periphery fuel nozzles if the load of the gas turbine is increased to a first set value; and

(3) and a step of increasing the opening degree of the first fuel control valve and supplying a mixed gas fuel of the starting fuel and the main fuel to the inner peripheral fuel nozzle if the load of the gas turbine further increases to a second set value.

3. The gas turbine combustor of claim 2,

the controller executes the following steps:

(4) closing the first fuel control valve to stop the supply of the main fuel to the inner periphery fuel nozzle and reducing the opening degree of the second fuel control valve if the opening degree of the second fuel control valve is reduced and the load of the gas turbine is reduced to a third set value; and

(5) and a step of closing the second fuel control valve and shifting to a special combustion state of the starting fuel if the load of the gas turbine is further reduced to a fourth set value, and then reducing the opening degree of the starting fuel control valve to zero and turning off the engine.

4. The gas turbine combustor of claim 2,

the controller executes the following steps:

(4) and closing the starting fuel control valve to stop the supply of the starting fuel to the inner periphery fuel nozzle and to shift to a main fuel combustion state in which only the main fuel is injected from all of the plurality of outer periphery fuel nozzles and the inner periphery fuel nozzle, if the load of the gas turbine further increases to a third set value.

5. The gas turbine combustor of claim 4,

the controller executes the following steps:

(5) reducing the opening degree of the second fuel control valve;

(6) a step of increasing the opening of the starting fuel control valve and supplying a mixed gas fuel of the starting fuel and the main fuel to the inner peripheral fuel nozzle if the load of the gas turbine decreases to a fourth set value;

(7) closing the first fuel control valve to stop the supply of the main fuel to the inner periphery fuel nozzle and reducing the opening degree of the second fuel control valve if the load of the gas turbine is further reduced to a fifth set value; and

(8) and closing the second fuel control valve to shift to a start-up fuel only combustion state, and then reducing the opening degree of the start-up fuel control valve to zero and turning off the engine if the load of the gas turbine is further reduced to a sixth set value.

6. The gas turbine combustor of claim 1,

the plurality of outer peripheral fuel nozzles are divided into a plurality of nozzle groups, and the second main fuel pipe branches into a plurality of nozzles and is connected to the corresponding nozzle groups.

7. The gas turbine combustor of claim 1,

the burner is provided with a plurality of the combustion nozzles.

8. The gas turbine combustor of claim 1,

the disclosed device is provided with:

a cylindrical liner forming a combustion chamber; and

an air hole plate disposed at an inlet of the liner and having a plurality of air holes for guiding compressed air to the combustion chamber,

the inner peripheral fuel nozzle and the plurality of outer peripheral fuel nozzles are arranged with their injection ports directed to the respective corresponding air holes on the opposite side of the combustion chamber with the air hole plate interposed therebetween,

the inner peripheral fuel nozzle and the plurality of outer peripheral fuel nozzles are arranged concentrically.

9. The gas turbine combustor of claim 1,

the disclosed device is provided with:

a cylindrical liner forming a combustion chamber; and

an air hole plate disposed at an inlet of the liner and having a plurality of air holes for guiding compressed air to the combustion chamber,

the injection ports of the inner peripheral fuel nozzle and the outer peripheral fuel nozzle are open to the inner wall surface of the air hole plate.

10. The gas turbine combustor of claim 1,

the starting fuel is natural gas or petroleum gas, and the main fuel is hydrogen-containing fuel.

11. A method of operating a gas turbine combustor using the gas turbine combustor of claim 1, the method of operating a gas turbine combustor characterized by,

increasing the opening degree of the fuel control valve for starting and supplying the fuel for starting to the inner peripheral fuel nozzle,

increasing the opening degree of the second fuel control valve and supplying the main fuel to the plurality of outer periphery fuel nozzles when the load of the gas turbine is increased to a first set value,

when the load of the gas turbine is increased to a second set value, the opening degree of the first fuel control valve is increased and the mixed gas fuel of the starting fuel and the main fuel is supplied to the inner peripheral fuel nozzle.

12. The method of operating a gas turbine combustor according to claim 11,

closing the first fuel control valve to stop the supply of the main fuel to the inner periphery fuel nozzle and reducing the opening degree of the second fuel control valve if the opening degree of the second fuel control valve is reduced and the load of the gas turbine is reduced to a third set value,

if the load of the gas turbine is further reduced to a fourth set value, the second fuel control valve is closed to shift to a special combustion state of the starting fuel, and then the opening of the starting fuel control valve is reduced to zero to shut off the engine.

13. The method of operating a gas turbine combustor according to claim 11,

when the load of the gas turbine further increases to a third set value, the start-up fuel control valve is closed to stop the supply of the start-up fuel to the inner periphery fuel nozzle, and the state shifts to a private combustion state in which only the main fuel of the main fuel is injected from all of the plurality of outer periphery fuel nozzles and the inner periphery fuel nozzle.

14. The method of operating a gas turbine combustor according to claim 13,

the opening degree of the second fuel control valve is decreased,

when the load of the gas turbine is reduced to a fourth set value, the opening degree of the starting fuel control valve is increased and the mixed gas fuel of the starting fuel and the main fuel is supplied to the inner peripheral fuel nozzle,

closing the first fuel control valve to stop the supply of the main fuel to the inner periphery fuel nozzle and reducing the opening degree of the second fuel control valve when the load of the gas turbine is further reduced to a fifth set value,

if the load of the gas turbine is further reduced to a sixth set value, the second fuel control valve is closed to shift to a special combustion state of the starting fuel, and then the opening of the starting fuel control valve is reduced to zero to shut off the engine.

Technical Field

The present invention relates to a gas turbine combustor and an operation method thereof.

Background

In recent years, from the viewpoints of suppressing global warming, effectively utilizing resources, and reducing power generation costs, it has been demanded to effectively utilize by-product gases such as coke oven gas by-produced in steel plants and exhaust gas by-produced in oil refineries as power generation fuel. In addition, the present invention has also drawn attention to an Integrated Gasification Combined Cycle (IGCC) system for generating electricity by gasifying coal, which is a rich resource. In an integrated coal gasification combined cycle power generation system, a system (Carbon Capture and Storage: CCS) for reducing Carbon dioxide (CO) by recovering and storing a Carbon component in a gas fuel supplied to a gas turbine is studied₂) A method of displacement. Hydrogen (H) due to gaseous fuel₂) As a main component, CO can be reduced compared to natural gas (methane as a main component) generally used in a gas turbine₂The displacement contributes to suppression of global warming. Further, power generation using pure hydrogen fuel is also being studied in view of the realization of the future hydrogen society. If pure hydrogen can be used as a fuel to generate electricity, CO can be completely prevented from being discharged₂Zero emission power generation. As described above, hydrogen-containing fuels are expected from the viewpoint of suppressing global warming, effectively utilizing resources, and reducing power generation costs.

However, when hydrogen is combusted, the maximum adiabatic flame temperature in the combustion region is locally higher than when natural gas is combusted, and therefore, the emission amount of nitrogen oxides (NOx) as an environmental pollutant in the combustion gas may increase. In addition, since hydrogen gas has a higher combustion speed than natural gas, there is a possibility that the flame may flow backward before reaching the combustion mouth portion upstream of the combustor, and there is a fear that the reliability of the combustor is lowered. Therefore, a lean combustion type combustor is known in which the dispersion of fuel is improved to prevent local formation of high-temperature flame, thereby reducing NOx emission and preventing backflow of flame (patent document 1 and the like). In the combustor of this aspect, for example, an air hole plate having a plurality of air holes and a plurality of fuel nozzles are provided, fuel is injected from each fuel nozzle into the corresponding air hole, and a coaxial jet flow formed by a fuel flow and an air flow surrounding the fuel is supplied to the combustion chamber.

When a hydrogen-containing fuel is used as the fuel for the gas turbine, if the ignition fails in the combustor and the unburned hydrogen-containing fuel is discharged from the combustor and accumulated in the turbine, the fuel may be burned in the turbine. As a countermeasure, there is an operation method in which a hydrogen-containing fuel is supplied after ignition with a hydrogen-free starting fuel. As one of them, an example is known in which ignition is performed with an oil fuel and the fuel is switched to a hydrogen-containing fuel (patent documents 2 and 3). An example is also known in which after a pilot burner disposed at the center is ignited with natural gas, natural gas is applied to a part of a plurality of main burners, and mixed combustion of hydrogen-containing fuel is applied to the remaining burners (patent document 4).

Documents of the prior art

Patent document 1: japanese patent laid-open publication No. 2003-148734

Patent document 2: japanese patent laid-open publication No. 2014-105601

Patent document 3: japanese patent laid-open publication No. 2018-71354

Patent document 4: japanese patent laid-open publication No. 2016-75448

In patent documents 2 to 4, the fuel nozzle for injecting the start-up fuel cannot inject the hydrogen-containing fuel. Therefore, if the fuel injection region of the fuel nozzle for starting fuel cannot be supplied with fuel when the fuel is shifted to the fuel-only operation with hydrogen-containing fuel, the dispersibility of the gaseous fuel is reduced, which is disadvantageous from the viewpoint of reducing the NOx emission.

Disclosure of Invention

The purpose of the present invention is to provide a gas turbine combustor and an operating method thereof, wherein a hydrogen-containing fuel can be stably ignited by a hydrogen-free gas fuel, and the dispersibility of the hydrogen-containing fuel can be improved.

In order to achieve the above object, the present invention provides a gas turbine combustor including a combustion nozzle, the gas turbine combustor including a starting fuel pipe through which a starting fuel flows, a first main fuel pipe through which a main fuel flows, a second main fuel pipe through which a main fuel flows, a fuel mixer to which the starting fuel pipe and the first main fuel pipe are connected, an inner peripheral fuel nozzle to which the fuel mixer is connected, a plurality of outer peripheral fuel nozzles to which the second main fuel pipe is connected, a starting fuel control valve provided in the starting fuel pipe, a first fuel control valve provided in the first main fuel pipe, and a second fuel control valve provided in the second main fuel pipe.

The effects of the present invention are as follows.

According to the present invention, it is possible to stably ignite a hydrogen-containing fuel with a hydrogen-free gas fuel and to improve the dispersibility of the hydrogen-containing fuel.

Drawings

Fig. 1 is a schematic configuration diagram of a gas turbine generator including a gas turbine combustor according to a first embodiment of the present invention.

Fig. 2 is a view of a combustion nozzle provided in a gas turbine combustor according to a first embodiment of the present invention, as viewed from a combustion chamber.

Fig. 3 is an explanatory diagram of an operation method (at startup) of the gas turbine combustor according to the first embodiment of the present invention.

Fig. 4 is an explanatory diagram of an operation method (at the time of stop) of the gas turbine combustor according to the first embodiment of the present invention.

Fig. 5 is a diagram illustrating the effect of the present invention.

Fig. 6 is a schematic configuration diagram of a gas turbine generator including a gas turbine combustor according to a second embodiment of the present invention.

Fig. 7 is a schematic configuration diagram of a gas turbine generator including a gas turbine combustor according to a third embodiment of the present invention.

Fig. 8 is a view of a burner tip provided in a gas turbine combustor according to a third embodiment of the present invention, as viewed from a combustion chamber.

Fig. 9 is an explanatory diagram of an operation method (at startup) of a gas turbine combustor according to a third embodiment of the present invention.

Fig. 10 is an explanatory diagram of an operation method (at the time of stop) of a gas turbine combustor according to a third embodiment of the present invention.

Fig. 11 is a schematic configuration diagram of a gas turbine generator including a gas turbine combustor according to a fourth embodiment of the present invention.

Fig. 12 is a view of a burner tip provided in a gas turbine combustor according to a fourth embodiment of the present invention, as viewed from a combustion chamber.

Fig. 13 is an explanatory diagram of an operation method (at startup) of a gas turbine combustor according to a fourth embodiment of the present invention.

Fig. 14 is an explanatory diagram of an operation method (at the time of stop) of a gas turbine combustor according to a fourth embodiment of the present invention.

In the figure: 3-gas turbine combustor, 5-combustion chamber, 8-burner, 12-liner, 20-air hole plate, 21-fuel nozzle (inner peripheral fuel nozzle), 22, 23-fuel nozzle (outer peripheral fuel nozzle), 31-pilot burner (burner), 32-main burner (burner), 51-53-air hole, 57-starting fuel pipe, 59-main fuel pipe (first main fuel pipe), 60-main fuel pipe (second main fuel pipe), 60A-60C-branch pipe (second main fuel pipe), 61-fuel mixer, 64-fuel control valve (starting fuel control valve), 65-fuel control valve (first fuel control valve), 66A-66C-fuel control valve (second fuel control valve), 70-controller, injection port 701-703-injection port, f1 starting fuel, F2 main fuel, F2a-F2c outer circumference burner (nozzle group), L1, L1a first setting value, L2 second setting value, L3 third setting value, L4 fourth setting value, L5, L5c fifth setting value, L6, L6A sixth setting value.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings.

(first embodiment)

Gas turbine generator

Fig. 1 is a schematic configuration diagram of a gas turbine generator including a gas turbine combustor according to a first embodiment of the present invention. Fig. 2 is a view of a combustion nozzle provided in a gas turbine combustor according to a first embodiment of the present invention, as viewed from a combustion chamber.

The gas turbine generator 1 includes an air compressor 2, a gas turbine combustor (hereinafter simply referred to as a combustor) 3, a turbine 4, and a generator 6. The air compressor 2 sucks and compresses air a1, and supplies compressed air a2 to the combustor 3, and the combustor 3 mixes and combusts the compressed air a2 with gas fuel (starting fuel f1, main fuel f2) to generate combustion gas g 1. The turbine 4 is driven by the combustion gas g1 generated in the combustor 3, and the combustion gas g1 that drives the turbine 4 is discharged as exhaust gas g 2. The generator 6 is driven by the rotational force of the turbine 4 to generate electric power. The gas turbine is driven by the starting motor 7 only at the start of starting.

Gas turbine combustor

The combustor 3 is mounted on a casing (not shown) of a gas turbine, and includes a liner (inner tube) 12, a sleeve (outer tube) 10, a burner 8, and a fuel system 200. The liner 12 is a cylindrical member and forms the combustion chamber 5 therein. The sleeve 10 is a cylindrical member having an inner diameter larger than that of the liner 12 and surrounding the outer periphery of the liner 12, and forms a cylindrical air flow path 9 with the liner 12. The end of the sleeve 10 opposite the turbine 4 (left side in fig. 1) is closed by an end shield 13. The compressed air a2 from the air compressor 2 flows through the sleeve 10 in the air flow path 9 formed on the outer periphery of the liner 12 in a direction away from the turbine 4, and the compressed air a2 flowing through the air flow path 9 convectively cools the outer peripheral surface of the liner 12. Further, a plurality of holes are formed in the wall surface of the liner 12, and a part a3 of the compressed air a2 flowing through the air flow path 9 flows into the combustion chamber 5 through the holes, so that the film cools the inner peripheral surface of the liner 12. The compressed air a2 that has reached the burner tip 8 through the air flow path 9 is discharged into the combustion chamber 5 together with the gaseous fuel supplied from the fuel system 200 to the burner tip 8 and is combusted. The combustion chamber 5 combusts a mixed gas fuel of the compressed air a2 and the gas fuel to generate a combustion gas g1, and the combustion gas g is supplied to the turbine 4 through a combustor transition piece (not shown).

As shown in fig. 1, the burner 8 is provided with only one air hole plate 20, fuel nozzles 21 to 23, and a fuel distributor (fuel head) 24, which are disposed at an inlet (an end opening on the opposite side of the turbine 4) of the liner 12.

The air hole plate 20 is a circular plate coaxial with the liner 12, and is disposed at an inlet (an end opening on the opposite side to the turbine 4) of the liner 12. The air hole plate 20 is provided with a plurality of air holes 51 to 53 for introducing compressed air a2 into the combustion chamber 5. The air holes 51 to 53 form a plurality of concentric annular rows around the center axis O of the liner 12. The air holes 51 belong to the first row (innermost row), the air holes 52 belong to the second row, and the air holes 53 belong to the third row (outermost row). The air holes 51 constitute inner peripheral air holes, and the air holes 52 and 53 constitute outer peripheral air holes. In the present embodiment, the air holes 51 to 53 are provided with a rotation angle, and the outlet of each hole is offset to one side in the circumferential direction with respect to the inlet.

The fuel nozzles 21 to 23 are supported by a fuel distributor 24 and are disposed on the opposite side of the combustion chamber 5 with an air hole plate 20 interposed therebetween. The number and positions of the fuel nozzles 21 to 23 correspond to the air holes 51 to 53 (one fuel nozzle for each air hole), and the air holes 51 to 53 constitute a plurality of concentric annular rows around the center axis O of the liner 12. The fuel nozzles 21 belong to the annular row of the first row (innermost circumference), the fuel nozzles 22 belong to the annular row of the second row, and the fuel nozzles 23 belong to the annular row of the third row (outermost circumference). The fuel nozzle 21 constitutes an inner peripheral fuel nozzle, and the fuel nozzles 22, 23 constitute outer peripheral fuel nozzles. The fuel nozzles 21 to 23 have injection ports directed to inlets of the corresponding air holes, and inject the gaseous fuel to the corresponding air holes. By injecting fuel from the plurality of fuel nozzles into the corresponding air holes in this manner, the fuel and the coaxial jet of air covering the periphery of the fuel flow with the air flow are dispersedly injected from each air hole into the combustion chamber 5.

Further, the number of fuel nozzles and air holes increases in the outer annular row due to the difference in the circumferences of the annular rows. That is, the number of the fuel nozzles 21 and the air holes 51 (6 each in the example of fig. 2) in the first row (innermost circumference) is smaller than the number of the fuel nozzles 22 and the air holes 52 (12 each in the example of fig. 2) in the second row. The number of the fuel nozzles 22 and the air holes 52 in the second row is smaller than the number of the fuel nozzles 23 and the air holes 53 in the third row (the outermost periphery) (18 each in the example of fig. 2).

The fuel distributor 24 is a member that distributes and supplies fuel to the fuel nozzles 21 to 23, and includes a plurality of fuel chambers 25 and 26 inside. The fuel chambers 25 and 26 are spaces that function to distribute and supply the gaseous fuel to the plurality of fuel nozzles belonging to the corresponding annular rows. The fuel chamber 25 is formed in a columnar shape on the central axis O of the liner 12, and the fuel chamber 26 is formed in a cylindrical shape so as to surround the outer periphery of the fuel chamber 25. In the present embodiment, each fuel nozzle 21 is connected to the fuel chamber 25, and each fuel nozzle 22, 23 is connected to the fuel chamber 26. When the gas fuel is supplied into the fuel chamber 25, the gas fuel is distributed to and discharged from each fuel nozzle 21 arranged in the innermost annular row, and the gas fuel is discharged from each air hole 51 to the combustion chamber 5 together with the compressed air a2. When the gas fuel is supplied to the fuel chamber 26, the gas fuel is distributed to and discharged from the fuel nozzles 22 and 23 arranged in the annular rows of the second row and the third row, and the gas fuel is discharged from the air holes 52 and 53 to the combustion chamber 5 together with the compressed air a2.

The fuel system 200 includes fuel supply sources 55 and 56, a starting fuel pipe 57, a main flow pipe 58, main fuel pipes 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 supply source of the starting fuel f 1. The starting fuel f1 is a fuel that does not contain hydrogen such as a hydrocarbon fuel or a gas fuel having a hydrogen content of several% (for example, 5%) or less. Typical examples of the hydrocarbon fuel include natural gas containing methane as a main component and petroleum gas containing propane and butane as main components. The fuel supply source 56 is a supply source of the main fuel f 2. The main fuel f2 is a hydrogen-containing fuel having a hydrogen content of several% (e.g., 5%) to several tens% such as a secondary gas. Pure hydrogen (hydrogen content of 100%) is also one type of hydrogen-containing fuel.

The starting fuel pipe 57 extends from the fuel supply source 55, and the starting fuel f1 flows through the starting fuel pipe 57. A main flow pipe 58 extending from the fuel supply source 56 branches into a first main fuel pipe 59 and a second main fuel pipe 60, and the main fuel f2 flows through the main fuel pipes 59 and 60. The starting fuel pipe 57 and the first main fuel pipe 59 are connected to a fuel mixer 61 and join together. The fuel mixer 61 is connected to the fuel chamber 25 by a connection pipe 68, and is connected to each fuel nozzle 21 on the inner periphery by the fuel chamber 25. The second main fuel pipe 60 is connected to the fuel chamber 26, and is connected to the outer peripheral fuel nozzles 22 and 23 through the fuel chamber 26. The starting fuel pipe 57 is provided with a fuel cut valve 62 and a fuel control valve (starting fuel control valve) 64. Further, a fuel control valve 65 (first fuel control valve) is provided in the first main fuel pipe 59, and a fuel control valve 66 (second fuel control valve) is provided in the second main fuel pipe 60. A fuel shutoff valve 63 is provided between the fuel supply source 56 (i.e., the main flow pipe 58) and a branching portion of the main fuel pipes 59 and 60.

The startup fuel f1 is supplied to the startup fuel pipe 57 by opening the fuel cut valve 62, and the supply of the startup fuel f1 to the startup fuel pipe 57 is cut off by closing the fuel cut valve 62. The main fuel f2 is supplied to the main fuel pipes 59 and 60 by opening the fuel cut valve 63, and the supply of the main fuel f2 to the main fuel pipes 59 and 60 is cut off by closing the fuel cut valve 63. The fuel control valves 64 to 66 function to adjust the fuel flow rate in accordance with the opening degree, and can shut off the flow of fuel even when in the fully closed state.

For example, by opening the fuel cut valve 62 and closing the fuel cut valve 63, the opening degree of the fuel control valve 64 is increased from the fully closed state to increase the supply flow rate of the starting fuel f1 to the fuel chamber 25, and only the starting fuel f1 is discharged from the fuel nozzle 21. Conversely, by opening the fuel cut valve 63 and closing the fuel cut valve 62, the opening degree of the fuel control valve 65 is increased from the fully closed state to increase the supply flow rate of the main fuel f2 to the fuel chamber 25, and only the main fuel f2 is discharged from the fuel nozzle 21. When the fuel shut-off valves 62 and 63 are simultaneously opened and the opening degrees of the fuel control valves 64 and 65 are increased from the fully closed state, the starting fuel f1 and the main fuel f2 are mixed in the fuel mixer 61, and a mixed gas fuel of both fuels is ejected from the fuel nozzle 21 through the fuel cavity 25. When the opening degree of the fuel control valve 66 is increased from the fully closed state with the fuel cut valve 63 opened, the supply flow rate of the main fuel f2 to the fuel chamber 26 increases, and only the main fuel f2 is discharged from the fuel nozzles 22 and 23.

In the present embodiment, the case where the annular rows of air holes are 3 rows is described as an example, but 2 rows or 4 rows or more may be used. By increasing the number of rows, the number of rows can be increased to correspond to a large-capacity gas turbine, and the operation controllability can be improved.

The combustor 3 is provided 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-off valves 62, 63 and the fuel control valves 64 to 66 based on the load of the gas turbine detected by the sensor 71. In the present embodiment, the output of the generator 6 and the number of revolutions of the turbine 4 are measured as the load of the gas turbine, and an electricity meter or a revolution sensor can be used as the sensor 71. Further, since the load of the gas turbine is in a proportional relationship with the fuel flow rate, a flow meter for measuring the fuel supply flow rate and the opening degree of the fuel control valves 64 to 66 can be used as the sensor 71.

The controller 70 is a computer, and includes an input interface, a ROM (e.g., EPROM), a RAM, a CPU, a timer, an output interface, and the like. The input interface receives a detection signal output from the sensor 71 and an operation signal output from an input device (not shown) in response to an operation by an operator. The ROM stores calculation formulas, programs, and data necessary for the operation of the gas turbine facility including the combustor 3. The RAM stores, for example, values in the middle of calculation, data input from an input device, and the like. The output interface outputs command signals to the fuel shut-off valves 62 and 63, the fuel control valves 64 to 66, and other operating devices (e.g., IGVs) disposed in the gas turbine plant, in accordance with the CPU commands.

The CPU executes control of the fuel cut valves 62, 63, the fuel control valves 64 to 66, and the like based on data input through the input interface in accordance with a program loaded from the ROM.

-actions-

The following describes an operation method of the combustor 3 in the present embodiment. The operation method described below is automatically executed by the controller 70 in accordance with the load of the gas turbine detected by the sensor 71, but may be performed by an operator by an appropriate manual operation while monitoring the load of the gas turbine. The flow rates of the starting fuel f1 and the main fuel f2 are determined based on the load of the gas turbine such as the power generation output, and the opening degrees of the fuel control valves 64, 65, and 66 are controlled so as to supply the fuel flow rate corresponding to the load of the gas turbine.

Fig. 3 is an explanatory diagram of an operation method (at startup) of the combustor according to the first embodiment. An example of the operation method at the time of startup from the ignition of the startup fuel f1 to the transition to the rich burn state of the main fuel f2 will be described with reference to fig. 3. The horizontal axis in the figure represents the load of the gas turbine, and the load increases toward the right. The upper tier of the figure shows the change in the flow rate of the starting fuel f1 and the main fuel f2 together with the burner tip diagram, and the lower tier shows the change in the flow rate of the gas fuel supplied to the inner peripheral fuel nozzles 21 and the outer peripheral fuel nozzles 22 and 23 together with the burner tip diagram. The inner peripheral burner F1 shown in the burner schematic diagram is a circular burner on the inner peripheral side including the fuel nozzle 21, and the outer peripheral burner F2 is a circular burner on the outer peripheral side including the fuel nozzles 22 and 23.

In the present embodiment, the controller 70 or the operator sequentially executes the following four steps (1) to (4) to perform an operation from the ignition to the rated load.

(1) The starting fuel F1 is supplied to the fuel nozzle 21 (inner circumferential burner F1) in a state where no fuel is supplied to the fuel nozzles 22 and 23 (outer circumferential burner F2).

(2) While the supply of the starting fuel F1 to the fuel nozzle 21 (inner circumferential burner F1) is continued, the main fuel F2 is supplied to the fuel nozzles 22 and 23 (outer circumferential burner F2).

(3) The main fuel F2 is continuously supplied to the fuel nozzles 22 and 23 (the outer circumferential burner F2), the supply of the main fuel F2 to the fuel nozzle 21 (the inner circumferential burner F1) is started, and the fuel supplied to the fuel nozzle 21 is switched from the starting fuel F1 to a mixed gas fuel of the starting fuel F1 and the main fuel F2.

(4) The supply of the starting fuel F1 to the fuel nozzle 21 (inner peripheral burner F1) is stopped, and only the main fuel F2 is supplied to all the fuel nozzles 21 to 23 (both the inner peripheral burner F1 and the outer peripheral burner F2).

The fuel supply state in the above steps (1) to (4) corresponds to the burner tip diagrams (1) to (4) of the same number shown in the lower layer of fig. 3. The valve actions in steps (1) to (4) are described separately.

Step (1)

The rotor of the gas turbine is started to rotate by the starting motor 7, and if the load of the gas turbine (for example, the number of revolutions of the turbine 4 or the power generation output of the generator 6) increases to the set value L0 that satisfies the ignitable condition, the controller 70 executes step (1). In this step, the controller 70 outputs signals S2, S4 (fig. 1) to the fuel cut valve 62 and the fuel control valve 64, opens the fuel cut valve 62, and opens the fuel control valve 64, for example, to increase the opening degree at a predetermined rate of increase. As a result, the starting fuel F1 is discharged from the fuel nozzle 21 of the inner peripheral burner F1 and ignited, and the starting fuel F1 increases at a predetermined increasing rate to increase the load of the gas turbine. During this period, the fuel cut valve 63 and the fuel control valves 65 and 66 are closed. When the operator adjusts the fuel flow rate, the opening degrees of the fuel cut valves 62, 63 and the fuel control valves 64 to 66 are manually operated by the operating device (not shown) as described above.

Step (2)

If the load of the gas turbine rises to the first set value L1 (> L0), the controller 70 outputs signals S2, S3, S4, S6 (fig. 1) to the fuel cut valves 62, 63 and the fuel control valves 64, 66 to execute step (2). In this step, the controller 70 opens the fuel cut valves 62, 63 and maintains the opening degree of the fuel control valve 64, and opens the fuel control valve 66, for example, to increase the opening degree at a predetermined rate of increase. Thus, the main fuel F2 starts to be discharged from the fuel nozzles 22 and 23 of the outer peripheral burner F2 while the injection amount of the starting fuel F1 from the fuel nozzle 21 of the inner peripheral burner F1 is maintained, and the main fuel F2 is ignited by the flame formed by the starting fuel F1 as a flame. Further, the main fuel f2 is increased at a predetermined increase rate to increase the load of the gas turbine. During this period, the fuel control valve 65 is closed. When the operator adjusts the fuel flow rate, the opening degrees of the fuel cut valves 62, 63 and the fuel control valves 64 to 66 are manually operated by the operating device (not shown) as described above.

Step (3)

If the load of the gas turbine is raised to the second set value L2 (> L1), the controller 70 inputs signals S2-S6 (FIG. 1) to the fuel cut valves 62, 63 and the fuel control valves 64-66 to perform step (3). In this step, the controller 70 opens the fuel cut valves 62 and 63, increases the opening degrees of the fuel control valves 65 and 66 by a predetermined increase rate, for example, and reduces the opening degree of the fuel control valve 64 to zero. As a result, the mixed gas fuel of the starting fuel F1 and the main fuel F2 starts to be ejected from the fuel nozzle 21 of the inner peripheral burner F1, and the main fuel concentration of the mixed gas fuel increases and the injection amount of the main fuel F2 from the fuel nozzles 22 and 23 of the outer peripheral burner F2 also increases. The main fuel f2 that starts to be injected from the fuel nozzle 21 is stably combusted together with the starting fuel f 1. During this period, the flow rate of the starting fuel f1 is reduced, but the load on the gas turbine is further increased by the increase in the main fuel f 2. When the operator adjusts the fuel flow rate, the opening degrees of the fuel cut valves 62, 63 and the fuel control valves 64 to 66 are manually operated by the operating device (not shown) as described above.

Step (4)

When the opening degree of the fuel control valve 64 is reduced to 0 to stop the supply of the starting fuel f1 while increasing the supply amount of the main fuel f2, the gas turbine load is designed to reach the third set value L3 (> L2). That is, if the load of the gas turbine rises to the third set value L3, the controller 70 closes the fuel cut valve 62 and the fuel control valve 64 to stop the supply of the starting fuel f1 to the fuel nozzles 21 on the inner periphery. Thus, the fuel injection is shifted to the main fuel f2 in which only the main fuel f2 is injected from all the fuel nozzles 21 to 23 on the inner and outer peripheries. Then, the controller 70 outputs signals S3, S5, S6 (fig. 1) to the fuel cut valve 63 and the fuel control valves 65, 66, and increases the opening degrees (e.g., the total opening areas) of the fuel control valves 65, 66 by, for example, a predetermined increase rate in a state where the fuel cut valve 63 is opened. In this way, the load of the gas turbine is increased to the rated value LR, and the startup operation is completed. When the operator adjusts the fuel flow rate, the opening degrees of the fuel cut valves 62, 63 and the fuel control valves 64 to 66 are manually operated by the operating device (not shown) as described above.

According to this starting method, the main fuel f2 is stably ignited by the flame formed by ignition in the starting fuel f1, and the mixed combustion of the starting fuel f1 and the main fuel f2 can be stably and smoothly switched to the exclusive combustion of the main fuel f 2. However, in the present embodiment, the case where the main fuel f2 is transitioned to the rated load in the lean burn state is exemplified, but there is also a case where the main fuel f1 is transitioned to the rated load in the mixed burn state of the starting fuel f 2. In this case, the load may be shifted to the rated load in step (2) or (3). In this case, steps (3) and (4) or step (4) can be omitted.

Fig. 4 is an explanatory diagram of an operation method (at the time of stop) of the combustor according to the first embodiment. An example of the operation method from the lean burn state of the main fuel f2 to the shutdown state will be described with reference to fig. 4. The horizontal axis of the graph represents the load of the gas turbine, and the load decreases toward the right side. The upper layer of the figure shows changes in the flow rates of the starting fuel f1 and the main fuel f2 together with the burner tip diagram, and the lower layer shows changes in the flow rates of the gas fuels supplied to the inner peripheral fuel nozzles 21 and the outer peripheral fuel nozzles 22 and 23 together with the burner tip diagram.

In the present embodiment, the controller 70 or the operator sequentially executes the following four steps (5) to (8) to perform the operation from the rated load to the key-off.

(5) The supply amount of the main fuel F2 to the fuel nozzles 22 and 23 (the outer circumferential burner F2) is reduced in a state where only the main fuel F2 is supplied to all the fuel nozzles 21 to 23 (both the inner circumferential burner F1 and the outer circumferential burner F2).

(6) The main fuel F2 is continuously supplied to the fuel nozzles 22 and 23 (the outer circumferential burner F2), the supply of the starting fuel F1 to the burner nozzle 21 (the inner circumferential burner F1) is started, and the fuel supplied to the fuel nozzle 21 is switched from the main fuel F2 to the mixed gas fuel of the starting fuel F1 and the main fuel F2.

(7) The supply of the main fuel F2 to the fuel nozzle 21 (inner peripheral burner F1) is stopped, and the amount of the main fuel F2 supplied to the fuel nozzles 22 and 23 (outer peripheral burner F2) is reduced in a state where only the startup fuel F1 is supplied to the fuel nozzle 21 (inner peripheral burner F1).

(8) The main fuel F2 supply to the fuel nozzles 22 and 23 (outer circumferential burner F2) is stopped, and the fuel is supplied only to the fuel nozzle 21 (inner circumferential burner F1) and the supply flow rate of the startup fuel F1 to the fuel nozzle 21 (inner circumferential burner F1) is reduced, thereby turning off the engine.

The fuel supply state in the above steps (5) - (8) corresponds to the burner tip diagrams (5) - (8) of the same number shown in the lower layer of fig. 4. The valve operations in steps (5) to (8) will be described.

Step (5)

If a stop signal is input from an operation device (not shown), the controller 70 outputs signals S3, S5, S6 (fig. 1) to the fuel cut valve 63 and the fuel control valves 65, 66 to execute step (5). In this step, the controller 70 increases the opening degree of the fuel control valve 65 and decreases the opening degree of the fuel control valve 66, for example, by a predetermined increase rate in the total supply flow rate of the main fuel f2, with the fuel cut valve 63 open. During this period, the fuel cut valve 62 and the fuel control valve 64 are closed. When the operator adjusts the fuel flow rate, the opening degrees of the fuel cut valves 62, 63 and the fuel control valves 64 to 66 are manually operated by the operating device (not shown) as described above.

Step (6)

If the load of the gas turbine is reduced from the rated value LR to the fourth set value L4 (< LR), the controller 70 outputs signals S2-S6 (FIG. 1) to the fuel shut-off valves 62, 63 and the fuel control valves 64-66 to perform step (6). In this step, the controller 70, in a state where the fuel cut valves 62, 63 are opened, reduces the opening degree of the fuel control valve 66 and opens the fuel control valve 64, for example, increases the opening degree of the fuel control valve 64 at a predetermined rate of increase, while reducing the opening degree of the fuel control valve 65 to zero. As a result, the mixed gas fuel of the starting fuel F1 and the main fuel F2 starts to be injected from the fuel nozzle 21 of the inner peripheral burner F1, the starting fuel concentration of the mixed gas fuel increases, the injection amount of the main fuel F2 from the fuel nozzles 22 and 23 of the outer peripheral burner F2 decreases, and the load decreases. The combustion speed is reduced by the start fuel f1 being injected from the fuel nozzle 21. When the operator adjusts the fuel flow rate, the opening degrees of the fuel cut valves 62, 63 and the fuel control valves 64 to 66 are manually operated by the operating device (not shown) as described above.

Step (7)

If the load of the gas turbine further drops to the fifth set value L5 (< L4), the controller 70 outputs signals S2, S3, S4, S6 (FIG. 1) to the fuel cut valves 62, 63 and the fuel control valves 64, 66 to perform step (7). In this step, the controller 70 maintains the opening degree of the fuel control valve 64 while opening the fuel cut valves 62, 63, and decreases the opening degree of the fuel control valve 66 at a predetermined rate of increase, for example. Thus, the injection amount of the main fuel F2 from the fuel nozzles 22 and 23 of the outer peripheral burner F2 is reduced while the injection amount of the startup fuel F1 from the fuel nozzle 21 of the inner peripheral burner F1 is maintained, thereby reducing the load on the gas turbine. During this period, the fuel control valve 65 is closed, the supply of the main fuel F2 to the fuel nozzle 21 of the inner peripheral burner F1 is stopped, and the fuel nozzle approaches the fuel only combustion state of the starting fuel F1 with a decrease in the supply amount of the main fuel F2. When the operator adjusts the fuel flow rate, the opening degrees of the fuel cut valves 62, 63 and the fuel control valves 64 to 66 are manually operated by the operating device (not shown) as described above.

Step (8)

When the supply amount of the main fuel f2 is 0, the gas turbine load is set to the sixth set value L6 (< L5). That is, if the load on the gas turbine falls to the sixth set value L6, the controller 70 closes the fuel cut valve 63 and the fuel control valves 65 and 66 to stop the supply of the main fuel f2 to the fuel nozzles 21 to 23. This causes the fuel nozzle 21 on the inner periphery to be shifted to the fuel only combustion state of the starting fuel f1, which is the fuel for starting f1 ejected from the fuel nozzle. Then, the controller 70 outputs signals S2, S4 (fig. 1) to the fuel cut valve 62 and the fuel control valve 64, and reduces the opening degree of the fuel control valve 64 to zero at, for example, a predetermined rate of increase in a state where the fuel cut valve 62 is opened. In this process, the burner 8 is turned off to complete the shutdown. When the operator adjusts the fuel flow rate, the opening degrees of the fuel cut valves 62, 63 and the fuel control valves 64 to 66 are manually operated by the operating device (not shown) as described above.

According to this starting method, since the state of the main fuel f1 is exclusively burned before the shutdown, the main fuel f2 is prevented from being unburned and staying in the turbine downstream.

Effects-

Fig. 5 is a diagram illustrating the effect of the present invention. In the present embodiment, by supplying the main fuel f2 as the hydrogen-containing fuel after ignition with the starting fuel f1 such as natural gas, the main fuel f2 can be reliably ignited, and unburned fuel can be prevented from being discharged from the burner. The reason is described with reference to fig. 5. The approximate shape of the flame formed downstream of the burner tip is shown in this figure. The supply of the starting fuel f1 to the fuel nozzle 21 on the inner periphery is started, and the center flame 121 of the starting fuel f1 is formed in the center of the burner downstream of the air hole 51 on the inner periphery. Next, the main fuel f2 is supplied to the outer peripheral fuel nozzles 22 and 23, and the mixed gas fuel of the main fuel f2 and the compressed air a2 is discharged into the combustion chamber from the outer peripheral air holes 52 and 53. The gas fuel mixture containing the main fuel f2 injected into the combustion chamber from the outer peripheral air holes 52 and 53 is reliably ignited by the heat of the center flame 121 formed in the past, and the peripheral flame 122 generated by the main fuel f2 is formed around the center flame 121. In this way, the main fuel f2 can be reliably ignited by the central flame 121 formed in advance of the starting fuel f1, and the main fuel f2 can be prevented from being discharged from the combustor 3 without being combusted and staying inside the downstream turbine 4.

At this time, the fuel mixer 61 that supplies one or both of the starting fuel f1 and the main fuel f2 is connected to the fuel nozzle 21 on the inner periphery, so that the starting fuel f1, the main fuel f2, and the mixed gas fuel thereof can be injected from the same fuel nozzle 21 (the same injection port). Thus, even when the fuel injection device shifts to the fuel only operation in which the main fuel f2 is ignited after the start-up fuel f1 is injected, the main fuel f2 can be injected from the fuel nozzle 21 (injection port) for injecting the start-up fuel f 1. The main fuel f2 is also supplied to the region where the central flame 121 is formed by the starting fuel f1, and the dispersibility of the gas fuel can be appropriately maintained even after the transition to the exclusive-burn state of the main fuel f 2.

As described above, according to the present embodiment, it is possible to stably ignite the hydrogen-containing fuel with the gas fuel containing no hydrogen and to improve the dispersibility of the hydrogen-containing fuel. Since the gas turbine generator can be stably operated with the hydrogen-containing fuel, it can contribute to suppression of global warming. Further, the use of the by-product gas generated in a steel mill or an oil refinery as the main fuel f2 can ensure combustion stability, and therefore, contributes to effective utilization of resources and reduction in power generation cost.

Further, since the supply of the main fuel f2 is stopped before the shutdown and the state shifts to the rich burn state of the starting fuel f1, the occurrence of misfire before the supply of the main fuel f2 is stopped can be prevented during the shutdown, and the main fuel f2 can be prevented from remaining in an unburned state in the downstream turbine 4.

(second embodiment)

Fig. 6 is a schematic configuration diagram of a gas turbine generator including a gas turbine combustor according to a second embodiment of the present invention. This figure corresponds to fig. 1 of the first embodiment. In fig. 6, the same elements as those of the first embodiment are denoted by the same reference numerals as those of fig. 1, and description thereof is omitted. The present embodiment differs from the first embodiment in that the injection ports of the inner peripheral fuel nozzle 21A and the outer peripheral fuel nozzle 22A open to the inner wall surface of the air hole plate 20.

In the present embodiment, the injection port 701 of the fuel nozzle 21A is opened to the inner wall of the air hole 51, and the injection ports 702 and 703 of the fuel nozzle 22A are opened to the inner walls of the air holes 52 and 53. The fuel nozzle 21A is connected to the connection pipe 68, and the fuel nozzle 22A is connected to the main fuel pipe 60. The other structure is the same as that of the first embodiment.

Even with such a lean-burn type burner tip structure, the same effects can be obtained by controlling the fuel in the same manner as in the first embodiment.

(third embodiment)

-structure-

Fig. 7 is a schematic configuration diagram of a gas turbine generator including a gas turbine combustor according to a third embodiment of the present invention. Fig. 8 is a view of a burner tip provided in a gas turbine combustor according to a third embodiment of the present invention, as viewed from a combustion chamber. These drawings correspond to fig. 1 and 2 of the first embodiment. In fig. 7 and 8, the same elements as those of the first embodiment are denoted by the same reference numerals as those of fig. 1 and 2, and description thereof is omitted. The present embodiment differs from the first embodiment in that the outer peripheral fuel nozzles 22 and 23 are divided into a plurality of (3 in this example) nozzle groups, and the main fuel pipe 60 is branched into a plurality of (3 in this example) nozzle groups and connected to the corresponding nozzle groups.

In the present embodiment, the outer peripheral fuel nozzles 22 and 23 and the air holes 52 and 53 are divided into a plurality of regions X1 to X3 in the circumferential direction, the first nozzle group belongs to the region X1, the second nozzle group belongs to the region X2, and the third nozzle group belongs to the region X3. In the present embodiment, the fuel chamber for distributing the main fuel f2 to the outer peripheral fuel nozzles 22 and 23 is also divided into a plurality of (3 in the present example) fuel chambers 26a to 26 c. The fuel nozzles 22 and 23 constituting the first nozzle group are connected to a fuel chamber 26 a. The fuel nozzles 22 and 23 constituting the second nozzle group are connected to a fuel chamber 26 b. The fuel nozzles 22 and 23 constituting the third nozzle group are connected to a fuel chamber 26 c.

In the present embodiment, the main fuel pipe 60 is branched into a plurality of (3 in the present embodiment) branch pipes 60a to 60 c. The branch pipe 60a is connected to the fuel chamber 26a, the branch pipe 60b is connected to the fuel chamber 26b, and the branch pipe 60c is connected to the fuel chamber 26 c. The main fuel pipe 60 (the portion before branching into the branch pipes 60a to 60 c) is not provided with a fuel control valve, but in the present embodiment, the branch pipe 60a is provided with a fuel control valve 66a, the branch pipe 60b is provided with a fuel control valve 66b, and the branch pipe 60c is provided with a fuel control valve 66 c. The fuel control valves 66a to 66c are the same valves as the fuel control valve 66 of the first embodiment.

In other respects, this embodiment is the same as the first embodiment. Further, in the present embodiment, a burner having a structure in which the injection port of the fuel nozzle is opened on the inner wall surface of the air hole as in the second embodiment can also be applied. The number of nozzle groups is not limited to 3, and may be 4 or more or 2 as long as there are a plurality of nozzle groups. By increasing the number of nozzle groups, the flexibility of operation controllability can be improved in accordance with a large-capacity gas turbine. The nozzle group of the fuel nozzles 22 and 23 may be divided in the radial direction (i.e., in the annular row) instead of the circumferential direction.

-actions-

Fig. 9 is an explanatory diagram of an operation method (at startup) of the combustor in the third embodiment. This figure corresponds to figure 3 of the first embodiment. An example of the operation method at the time of startup from the ignition of the startup fuel f1 to the shift to the rich burn state of the main fuel f2 will be described with reference to fig. 9. The horizontal axis of the graph represents the load of the gas turbine, and the load increases toward the right side. In addition, the upper layer of the graph shows changes in the flow rates of the starting fuel f1 and the main fuel f2, and the lower layer shows changes in the flow rates of the gas fuel supplied to the nozzle groups of the inner fuel nozzle 21 and the outer fuel nozzles 22 and 23, together with the burner tip diagram. The inner peripheral burner tip F1 shown in the burner tip schematic diagram is a circular burner tip on the inner peripheral side including the fuel nozzle 21. The outer peripheral burner F2a is a fan-shaped burner including the fuel nozzles 22 and 23 of the first nozzle group. The outer peripheral burner F2b is a fan-shaped burner including the fuel nozzles 22 and 23 of the second nozzle group, and the outer peripheral burner F2c is a fan-shaped burner including the fuel nozzles 22 and 23 of the third nozzle group.

The starting procedure of the present embodiment is the same as that of the first embodiment except for the steps (2a) to (2c) in which the step (2) of the 4 steps (1) to (4) described in the first embodiment is divided into three stages. In the present embodiment, since steps (1), (3), and (4) are the same as those in the first embodiment, the description thereof will be omitted, and steps (2a) to (2c) will be described below. If step (1) is completed, the following steps (2a) - (2c) are performed in order, and if step (2c) is completed, steps (3) and (4) are performed as in the first embodiment. In the present embodiment, 3 fuel control valves 66a to 66c are disposed in the outer peripheral burner, and in steps (3) and (4), the fuel control valves 66a to 66c are similarly controlled.

Step (2a)

After the step (1) is performed, if the load of the gas turbine rises to the first set value L1a (> L0), the controller 70 outputs signals S2, S3, S4, S6a (fig. 7) to the fuel cut valves 62, 63 and the fuel control valves 64, 66a and performs a step (2 a). In this step, the controller 70 opens the fuel cut valves 62, 63, maintains the opening degree of the fuel control valve 64, and opens the fuel control valve 66a, for example, to increase the opening degree at a predetermined rate of increase. Thus, the main fuel F2 starts to be discharged from the fuel nozzles 22 and 23 of the outer peripheral burner F2a while the injection amount of the starting fuel F1 from the fuel nozzle 21 of the inner peripheral burner F1 is maintained, and the main fuel F2 is ignited by the flame formed by the starting fuel F1 as a flame. Then, the main fuel f2 is increased at a predetermined increase rate to increase the load of the gas turbine. During this period, the fuel control valves 65, 66b, 66c are closed. When the operator adjusts the fuel flow rate, the opening degrees of the fuel cut valves 62, 63 and the fuel control valves 64, 65, 66a-66c are manually operated by the operating device (not shown) as described above.

Step (2b)

If the load of the gas turbine rises to the set value L1b (> L1a), the controller 70 outputs signals S2, S3, S4, S6a, S6b (fig. 7) to the fuel cut valves 62, 63 and the fuel control valves 64, 66a, 66b to perform step (2 b). In this step, the controller 70 opens the fuel cut valves 62, 63, maintains the opening degrees of the fuel control valve 64 and the fuel control valve 66a, and newly opens the fuel control valve 66b, for example, increases the opening degrees at a predetermined rate of increase. This also allows smooth ignition of the main fuel F2 injected from the fuel nozzles 22 and 23 of the outer peripheral burner F2b, and increases the load on the gas turbine by increasing the supply amount of the main fuel F2 while expanding the supply range of the main fuel F2. During this period, the fuel control valves 65 and 66c are closed. When the operator adjusts the fuel flow rate, the opening degrees of the fuel cut valves 62, 63 and the fuel control valves 64, 65, 66a-66c are manually operated by the operating device (not shown) as described above.

Step (2c)

If the load of the gas turbine rises to the set value L1c (L1b < L1c < L2), the controller 70 outputs signals S2, S3, S4, S6a-S6c (FIG. 7) to the fuel cut valves 62, 63 and the fuel control valves 64, 66a-66c to perform step (2 c). In this step, the controller 70 opens the fuel cut valves 62, 63, maintains the opening degrees of the fuel control valve 64 and the fuel control valves 66a, 66b, and newly opens the fuel control valve 66c, for example, increasing the opening degree at a predetermined rate of increase. This smoothly ignites the main fuel F2 that has been injected from the fuel nozzles 22 and 23 of the outer peripheral burner F2c, and increases the supply amount of the main fuel F2 while expanding the supply range of the main fuel F2, thereby increasing the load on the gas turbine. During this period, the fuel control valve 65 is closed. When the operator adjusts the fuel flow rate, the opening degrees of the fuel cut valves 62, 63 and the fuel control valves 64, 65, 66a-66c are manually operated by the operating device (not shown) as described above.

Fig. 10 is an explanatory diagram of an operation method (at the time of stop) of the combustor according to the third embodiment. This figure corresponds to figure 4 of the first embodiment. An example of the operation method from the lean burn state of the main fuel f2 to the shutdown state will be described with reference to fig. 10. The horizontal axis of the graph represents the load of the gas turbine, and the load decreases toward the right side. In addition, the upper layer of the graph shows changes in the flow rates of the starting fuel f1 and the main fuel f2, and the lower layer shows changes in the flow rates of the gas fuel supplied to the nozzle groups of the inner fuel nozzle 21 and the outer fuel nozzles 22 and 23, together with the burner tip diagram.

The stop step of the present embodiment is the same as that of the first embodiment, except that the step (7) of the 4 steps (5) to (8) described in the first embodiment is divided into three steps (7a), (7b), and (7 c). In the present embodiment, steps (5), (6), and (8) are the same as those in the first embodiment, and therefore, the description thereof will be omitted, and steps (7c), (7b), and (7a) will be described below. If steps (5) and (6) are completed, the following steps (7c), (7b), and (7a) are sequentially executed, and if step (7a) is completed, step (8) is executed as in the first embodiment. In the present embodiment, 3 fuel control valves 66a to 66c are disposed for the outer peripheral burner, and the fuel control valves 66a to 66c are similarly controlled in steps (5) and (6).

Step (7c)

After the execution of step (6), if the load of the gas turbine falls to the fifth set value L5c (< L4), the controller 70 outputs signals S2, S3, S4, S6a-S6c (fig. 7) to the fuel cut valves 62, 63 and the fuel control valves 64, 66a-66c to execute step (7 c). In this step, the controller 70 maintains the opening degrees of the fuel control valves 64, 66a, 66b and reduces the opening degree of the fuel control valve 66c to zero at a predetermined rate of increase, for example, in a state where the fuel cut valves 62, 63 are opened. Thus, while maintaining the injection amounts of the startup fuel F1 from the inner peripheral burner F1 and the main fuel F2 from the outer peripheral burners F2a and F2b, the injection amount of the main fuel F2 from the outer peripheral burner F2c is reduced, thereby reducing the load on the gas turbine. During this period, the fuel control valve 65 is closed, and the supply of the main fuel F2 to the fuel nozzle 21 of the inner peripheral burner F1 is stopped. When the operator adjusts the fuel flow rate, the opening degrees of the fuel cut valves 62, 63 and the fuel control valves 64 to 66 are manually operated by the operating device (not shown) as described above.

Step (7b)

If the load of the gas turbine falls to the set value L5b (< L5c), the controller 70 outputs signals S2, S3, S4, S6a, S6b (fig. 7) to the fuel cut valves 62, 63 and the fuel control valves 64, 66a, 66b to perform step (7 b). In this step, the controller 70 maintains the opening degrees of the fuel control valves 64, 66a and reduces the opening degree of the fuel control valve 66b to zero at a predetermined rate of increase, for example, in a state where the fuel cut valves 62, 63 are opened. Thus, the load on the gas turbine is further reduced by reducing the injection amount of the main fuel F2 from the outer peripheral burner F2b while maintaining the injection amounts of the startup fuel F1 from the inner peripheral burner F1 and the main fuel F2 from the outer peripheral burner F2 a. During this period, the fuel control valves 65 and 66c are closed. When the operator adjusts the fuel flow rate, the opening degrees of the fuel cut valves 62, 63 and the fuel control valves 64 to 66 are manually operated by the operating device (not shown) as described above.

Step (7a)

If the load of the gas turbine falls to the set value L5a (L6 < L5a < L5b), the controller 70 outputs signals S2, S3, S4, S6a (FIG. 7) to the fuel cut valves 62, 63 and the fuel control valves 64, 66 to perform step (7 a). In this step, the controller 70 maintains the opening degree of the fuel control valve 64 and reduces the opening degree of the fuel control valve 66a to zero at a predetermined rate of increase, for example, in a state where the fuel cut valves 62, 63 are opened. Thus, the load on the gas turbine is further reduced by reducing the injection amount of the main fuel F2 from the outer peripheral burner F2a while maintaining the injection amount of the startup fuel F1 from the inner peripheral burner F1. During this period, the fuel control valves 65, 66b, 66c are closed. When the operator adjusts the fuel flow rate, the opening degrees of the fuel cut valves 62, 63 and the fuel control valves 64 to 66 are manually operated by the operating device (not shown) as described above.

Effects-

The same effects as those of the first embodiment can be obtained also in the present embodiment. Further, by dividing the outer fuel nozzles 22 and 23 into a plurality of nozzle groups and performing the supply start and stop of the main fuel f2 for each nozzle group to perform the ignition of the main fuel f2 in a stepwise manner, the discharge of the unburned main fuel f2 can be suppressed more reliably.

(fourth embodiment)

-structure-

Fig. 11 is a schematic configuration diagram of a gas turbine generator including a gas turbine combustor according to a fourth embodiment of the present invention. Fig. 12 is a view of a burner tip provided in a gas turbine combustor according to a fourth embodiment of the present invention, as viewed from a combustion chamber. These drawings correspond to fig. 1 and 2 of the first embodiment. In fig. 11 and 12, the same elements as those of the first embodiment are denoted by the same reference numerals as those of fig. 1 and 2, and description thereof is omitted. The present embodiment differs from the first embodiment in that it includes a composite burner configured such that the burner 3 includes a plurality of burners.

The burner 3 of the present embodiment includes a pilot burner 31 and a plurality of (6 in the present example) main burners 32, and is arranged such that the plurality of main burners 32 surround the periphery of the 1 pilot burner 31 arranged at the center. In the present embodiment, a case where the burner tip structure of the first embodiment is applied to the pilot burner 31 and each main burner 32 will be described as an example. However, the burners 8 of the first, second, and third embodiments can be applied to the pilot burner 31 and each main burner 32. For example, all the pilot burners 31 and the main burners 32 may be unified by any of the burners 8 of the first to third embodiments, and the burners 8 of the first to third embodiments may be appropriately mixed. The pilot burner 31 may be shared with the plurality of main burners 32 in the air hole plate 20 (the air holes 51 to 53 of the respective burners are formed in one air hole plate 20).

In the fuel system 200, the connection pipe 68 is branched into a plurality of (3 in this example) branch pipes 68A to 68C. The branch pipe 68A is connected to the fuel nozzle 21 (fuel chamber 25) on the inner periphery of the pilot burner 31. The branch pipe 68B is connected to the fuel nozzles 21 (fuel chambers 25) on the inner periphery of half of the main burners 32, and the branch pipe 68C is connected to the fuel nozzles 21 (fuel chambers 25) on the inner periphery of the remaining main burners 32. Further, the branch pipe 68A is provided with a fuel control valve 65A, the branch pipe 68B is provided with a fuel control valve 65B, and the branch pipe 68C is provided with a fuel control valve 65C. The fuel control valves 65A-65C are, for example, the same valves as the fuel control valves 65.

In the present embodiment, the main fuel pipe 60 branches into a plurality of (3 in the present embodiment) branch pipes 60A to 60C. The branch pipe 60A is connected to the outer peripheral fuel nozzles 22 and 23 (fuel chambers 26) of the pilot burner 31. The branch pipe 60B is connected to the fuel nozzles 22 and 23 (fuel chambers 26) on the outer periphery of half of the main burners 32, and the branch pipe 60C is connected to the fuel nozzles 22 and 23 (fuel chambers 26) on the outer periphery of the remaining main burners 32. The main fuel pipe 60 (the portion before branching into the branch pipes 60A to 60C) is not provided with a fuel control valve, but in the present embodiment, the branch pipe 60A is provided with a fuel control valve 66A, the branch pipe 60B is provided with a fuel control valve 66B, and the branch pipe 60C is provided with a fuel control valve 66C. The fuel control valves 66A to 66C are the same valves as the fuel control valve 66 of the first embodiment.

In other respects, this embodiment is the same as the first, second, or third embodiment.

-actions-

Fig. 13 is an explanatory diagram of an operation method (at startup) of the combustor in the fourth embodiment. This figure corresponds to figure 3 of the first embodiment. An example of the method of starting from the ignition of the starting fuel f1 to the rich burn to the main fuel f2 will be described with reference to fig. 13. The horizontal axis of the graph represents the load of the gas turbine, and the load increases toward the right side. In addition, the upper layer of the graph shows changes in the flow rates of the starting fuel f1 and the main fuel f2, and the lower layer shows changes in the flow rates of the fuel gas fuel supplied to the fuel nozzles 21 on the inner circumference and the fuel nozzles 22 and 23 on the outer circumference of the pilot burner 31 and the main burner 32, together with the burner tip diagram. The inner peripheral burner F11 shown in the burner schematic diagram is the inner peripheral burner (corresponding to the fuel nozzle 21) of the pilot burner 31, and the outer peripheral burner F12 is the outer peripheral burner (corresponding to the fuel nozzles 22 and 23) of the pilot burner 31. In addition, 3 of the main burners 32 spaced one by one in the circumferential direction are defined as a first group, and the remaining 3 are defined as a second group. The inner peripheral burner tip F21 is the inner peripheral burner tip (corresponding to the fuel nozzle 21) of the first group of main burner tips 32, and the outer peripheral burner tip F22 is the outer peripheral burner tip (corresponding to the fuel nozzles 22, 23) of the first group of main burner tips 32. The inner peripheral burner F31 is the inner peripheral burner (corresponding to the fuel nozzle 21) of the second group of main burners 32, and the outer peripheral burner 32 is the outer peripheral burner (corresponding to the fuel nozzles 22, 23) of the second group of main burners 32.

The starting procedure of the present embodiment is the same as that of the first embodiment except that the procedure (1) among the 4 procedures (1) to (4) described in the first embodiment is divided into two steps (1A) and (1B). The steps (1A) and (1B) are explained below. If the following steps (1A), (1B) are completed, steps (2) to (4) are performed as in the first embodiment. In the present embodiment, 3 fuel control valves 65A to 65C are provided for the starting fuel, and the fuel control valves 65A to 65C are similarly controlled in steps (2) to (4). In this main fuel, 3 fuel control valves 66A to 66C are arranged, and in steps (2) to (4), the fuel control valves 66A to 66C are similarly controlled.

Step (1A)

The controller 70 executes step (1A) if the rotor of the gas turbine is started to rotate by the starter motor 7 and the load of the gas turbine is increased to a set value L0A that satisfies the ignitability condition. In this step, the controller 70 outputs signals S2, S4, S5A, S5B (fig. 11) to the fuel cut valve 62 and the fuel control valves 64, 65A, 65B, and opens the fuel cut valve 62 and opens the fuel control valves 64, 65A, 65B at the same time, for example, to increase the opening degree at a predetermined rate of increase. As a result, the starting fuel F1 is discharged from the inner peripheral burners F11 and F21 and ignited, and the starting fuel F1 is increased at a predetermined increase rate to increase the load of the gas turbine. During this period, the fuel cut valve 63 and the fuel control valves 65, 65C, 66A to 66C are closed. When the operator adjusts the fuel flow rate, the opening degrees of the fuel cut valves 62, 63 and the fuel control valves 64, 65A-65C, 66A-66C are manually operated by the operating device (not shown) as described above.

Step (1B)

If the load of the gas turbine rises to the set value L0B (L0A < L0B < L1), the controller 70 performs step (1B). In this step, the controller 70 outputs signals S2, S4, S5A-S5C (FIG. 11) to the fuel cut valve 62 and the fuel control valves 64, 65A-65C to reopen the fuel control valve 65C, for example, to increase the opening of the fuel control valves 64, 65A-65C at a predetermined rate of increase. Thus, the starting fuel F1 is discharged from the inner peripheral burners F11 to F31 and is increased at a predetermined increase rate to increase the load of the gas turbine. During this period, the fuel cut valve 63 and the fuel control valves 65, 66A to 66C are closed. When the operator adjusts the fuel flow rate, the opening degrees of the fuel cut valves 62, 63 and the fuel control valves 64, 65A-65C, 66A-66C are manually operated by the operating device (not shown) as described above.

Fig. 14 is an explanatory diagram of an operation method (at the time of stop) of the combustor according to the fourth embodiment. This figure corresponds to figure 4 of the first embodiment. An example of an operation method from rated load to complete start-up will be described with reference to fig. 14. The horizontal axis of the graph represents the load of the gas turbine, and the load decreases toward the right side. In addition, the upper layer of the graph shows changes in the flow rates of the starting fuel f1 and the main fuel f2, and the lower layer shows changes in the flow rates of the gas fuel supplied to the fuel nozzles 21 on the inner circumference and the fuel nozzles 22 and 23 on the outer circumference of the pilot burner 31 and the main burner 32, together with the burner tip diagram.

The stop step of the present embodiment is the same as the first embodiment except for the point that the step (8) of the 4 steps (5) to (8) described in the first embodiment is divided into two steps (8A) and (8B). The steps (8A) and (8B) are explained below. If steps (5) to (7) are performed as in the first embodiment, the following steps (8A), (8B) are performed. In the present embodiment, 3 fuel control valves 65A to 65C are provided for the starting fuel, but the fuel control valves 65A to 65C are similarly controlled in steps (5) to (7). In this main fuel, 3 fuel control valves 66A to 66C are arranged, but in steps (5) to (7), the fuel control valves 66A to 66C are similarly controlled.

Step (8A)

If the step (7) is completed and the load of the gas turbine falls to the sixth set value L6A (< L5), the controller 70 outputs signals S2, S4, S5A-S5C (fig. 11) to the fuel cut valve 62 and the fuel control valves 64, 65A-65C to perform a step (8A). In this step, the controller decreases the opening degrees of the fuel control valves 64, 65A to 65C, for example, at a predetermined rate of increase in a state where the fuel cut valve 62 is opened. During this period, the fuel cut valve 63 and the fuel control valves 65, 66A to 66C are closed, and the starting fuel f1 is burned exclusively. When the operator adjusts the fuel flow rate, the opening degrees of the fuel cut valves 62, 63 and the fuel control valves 64, 65A-65C, 66A-66C are manually operated by the operating device (not shown) as described above.

Step (8B)

If the load of the gas turbine further drops to the set value L6B (< L6A), the controller 70 outputs signals S2, S4, S5A, S5B (fig. 11) to the fuel cut valve 62 and the fuel control valves 64, 65A, 65B to perform step (8B). In this step, the controller 70 reduces the opening degrees of the fuel control valves 64, 65A, 65B to zero, for example, at a predetermined increasing rate in a state where the fuel cut valve 62 is opened, and in the process, the combustor 3 processes to complete the shutdown. During this period, the fuel cut valve 63 and the fuel control valves 65, 65C, 66A to 66C are closed, and the number of injection burners for the startup fuel F1 is reduced to two of the inner peripheral burners F11 and F21. When the operator adjusts the fuel flow rate, the opening degrees of the fuel cut valves 62, 63 and the fuel control valves 64, 65A-65C, 66A-66C are manually operated by the operating device (not shown) as described above.

Effects-

By configuring the composite burner by appropriately applying the burner tip structures of the first to third embodiments to the pilot burner 31 and the main burner 32, the same effects as those of the respective embodiments or effects obtained by combining the embodiments can be obtained even when a large-capacity gas turbine is used.