Method for operating a gas turbine

Abstract

A method for operating a gas turbine according to one embodiment of the present invention is a method for operating a gas turbine provided with a combustor capable of using hydrogen and a fuel other than hydrogen as fuels. The combustor is provided with a nozzle having at least one first injection hole and at least one second injection hole. When a low-hydrogen co-combustion operation is performed, a first fuel is injected from the at least one first injection hole, and when a high-hydrogen co-combustion operation with a higher hydrogen co-combustion rate than the low-hydrogen co-combustion operation is performed, a second fuel having a higher hydrogen content than the first fuel is injected from the at least one first injection hole, and water is injected from the second injection hole.

Description

Technical Field

[0001] The present invention relates to an operating method for a gas turbine.

[0002] This application claims priority based on Japanese Patent Application No. 2022-192571 filed with the Japan Patent Office on December 1, 2022, and incorporates its content herein. Background Art

[0003] For example, in thermal power generation equipment, as a means of reducing the emission amount of carbon dioxide (CO2) that causes global warming, research is being conducted on improving power generation efficiency or actively using fuels such as hydrogen other than fossil fuels (for example, refer to Patent Document 1).

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2021-046949 Summary of the Invention

[0007] Technical Problem to be Solved by the Invention

[0008] In order to reduce the emission amount of carbon dioxide, it is preferable to increase the hydrogen co-firing rate. However, if the hydrogen co-firing rate is increased, the temperature of the flame rises and the generation amount of NO x tends to increase. Also, as the temperature of the flame rises, the metal temperature of the burner rises, which may lead to damage.

[0009] In view of the above circumstances, an object of at least one embodiment of the present invention is to suppress the generation of NO x while increasing the hydrogen co-firing rate during the operation of the gas turbine, and to suppress the possibility of burner damage.

[0010] Means for Solving the Technical Problem

[0011] (1) In the operating method for a gas turbine according to at least one embodiment of the present invention, the gas turbine includes a burner capable of using hydrogen and a fuel other than hydrogen as fuels. In the operating method for the gas turbine,

[0012] the burner includes a nozzle having at least one first injection hole and at least one second injection hole.

[0013] In the case of performing low hydrogen co-firing rate operation, a first fuel is injected from the at least one first injection hole.

[0014] In the case of performing a high hydrogen co - firing rate operation where the hydrogen co - firing rate is higher than the low hydrogen co - firing rate operation, a second fuel having a hydrogen content rate higher than that of the first fuel is injected from the at least one first injection hole, and water is injected from the second injection hole.

[0015] Advantages of the Invention

[0016] According to at least one embodiment of the present invention, during the operation of a gas turbine, it is possible to increase the hydrogen co - firing rate while suppressing the generation of NO x and to suppress the possibility of burner damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of a gas turbine according to several embodiments.

[0018] Figure 2 is a cross - sectional view of a burner according to several embodiments.

[0019] Figure 3 is a cross - sectional view of a main part of a burner according to several embodiments.

[0020] Figure 4 is a diagram schematically showing the arrangement of each fuel injector when observing the upstream side from the downstream side along the axial direction of the burner according to several embodiments.

[0021] Figure 5 is a diagram showing the outline of the structure near the tip of a pilot nozzle and the outline of a supply system in a burner according to several embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, several embodiments of the present invention will be described with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described as embodiments or shown in the drawings are not intended to limit the scope of the present invention thereto, but are merely illustrative examples.

[0023] For example, expressions indicating relative or absolute arrangements such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric", or "coaxial" not only represent such arrangements in a strict sense, but also represent a state of relative displacement in such a manner that there are tolerances or angles and distances that can achieve the same function.

[0024] For example, expressions indicating that things are in the same state such as "same", "equal", and "homogeneous" not only represent the same state in a strict sense, but also represent a state with differences in tolerances or degrees that can achieve the same function.

[0025] For example, expressions indicating shapes such as a quadrilateral shape and a cylindrical shape not only represent the shapes of a quadrilateral shape and a cylindrical shape in a strict geometric sense, but also represent shapes including concavo-convex portions, chamfered portions, etc. within a range where the same effects can be obtained.

[0026] On the other hand, the expressions "comprising", "being equipped with", "including", "containing", or "having" a constituent element are not exclusive expressions that exclude the existence of other constituent elements.

[0027] (Regarding the gas turbine 1)

[0028] Figure 1 It is a schematic structural diagram of the gas turbine 1 related to several embodiments.

[0029] Reference Figure 1 , a gas turbine, which is an example of an application mode of the operation method of the gas turbine related to several embodiments, will be described.

[0030] As Figure 1 shown, the gas turbine 1 operated by the operation method of the gas turbine related to several embodiments includes: a compressor 2 for generating compressed air as an oxidant; a gas turbine burner 4 for generating combustion gas using the compressed air and fuel; and a turbine 6 configured to be rotationally driven by the combustion gas. In the case of the gas turbine 1 for power generation, a generator (not shown) is connected to the turbine 6, and power generation can be performed by the rotation of the turbine 6. In the following description, the gas turbine burner 4 will also be simply referred to as the burner 4.

[0031] Specific structural examples of each part in the gas turbine 1 related to several embodiments will be described.

[0032] The compressor 2 related to several embodiments includes: a compressor chamber 10; an air intake 12 provided on the inlet side of the compressor chamber 10 for taking in air; a rotor 8 provided so as to penetrate both the compressor chamber 10 and a turbine chamber 22 described later; and various blades arranged in the compressor chamber 10. The various blades include: inlet guide vanes 14 provided on the air intake 12 side; a plurality of stationary blades 16 fixed to the compressor chamber 10 side; and a plurality of rotating blades 18 implanted on the rotor 8 so as to be alternately arranged with respect to the stationary blades 16. In addition, the compressor 2 may include other constituent elements such as an extraction chamber (not shown). In such a compressor 2, the air taken in from the air intake 12 is compressed by the plurality of stationary blades 16 and the plurality of rotating blades 18, and thus becomes high-temperature and high-pressure compressed air. And the high-temperature and high-pressure compressed air is transported from the compressor 2 to the burner 4 at the subsequent stage.

[0033] The burner 4 related to several embodiments is arranged in a housing 20. As Figure 1As shown, a plurality of burners 4 can be annularly arranged around a rotor 8 within a housing 20. Fuel and compressed air generated by a compressor 2 are supplied to the burners 4, and the fuel is burned to generate combustion gas as the working fluid for a turbine 6. Then, the combustion gas is transported from the burners 4 to the subsequent-stage turbine 6. In addition, structural examples of the burners 4 according to several embodiments will be described later.

[0034] The turbine 6 according to several embodiments includes a turbine chamber 22 and various blades disposed within the turbine chamber 22. The various blades include: a plurality of stationary blades 24 fixed to the turbine chamber 22 side; and a plurality of rotating blades 26 planted on the rotor 8 in an alternating arrangement with respect to the stationary blades 24. In addition, the turbine 6 may also include other structural components such as exit guide vanes. In the turbine 6, the combustion gas passes through the plurality of stationary blades 24 and the plurality of rotating blades 26, whereby the rotor 8 is rotationally driven. Thereby, the generator connected to the rotor 8 is driven.

[0035] On the downstream side of the turbine chamber 22, an exhaust chamber 30 is connected via an exhaust machine chamber 28. The combustion gas after driving the turbine 6 is discharged to the outside via the exhaust machine chamber 28 and the exhaust chamber 30.

[0036] (Regarding the burner 4)

[0037] Figure 2 is a cross-sectional view showing the burner 4 according to several embodiments. Figure 3 is a cross-sectional view of the main part of the burner 4 according to several embodiments. Figure 4 is a diagram schematically showing the arrangement of each fuel injector when observing the upstream side from the downstream side along the axial direction of the burner 4 for the burner 4 according to several embodiments.

[0038] Reference Figure 2 、 Figure 3 and Figure 4 are used to explain the structure of the burner 4 according to several embodiments.

[0039] As Figure 2 and Figure 3 shown, a plurality of burners 4 according to several embodiments are annularly arranged around a rotor 8 (reference Figure 1 ). Each burner 4 includes: a burner liner 46 provided in a burner chamber 40 defined by the housing 20; and a main combustion burner 60 and a pilot combustion burner 50 as fuel injectors respectively disposed within the burner liner 46.

[0040] The burner 4 further includes an outer cylinder 45 which is disposed on the outer peripheral side of the inner cylinder 47 of the burner liner 46 inside the housing 20. An air passage 43 for the flow of compressed air is formed on the outer peripheral side of the inner cylinder 47 and the inner peripheral side of the outer cylinder 45.

[0041] In addition, the burner 4 may also include other components such as a bypass pipe (not shown) for bypassing the combustion gas.

[0042] For example, the burner liner 46 has: an inner cylinder 47 disposed around the pilot burner nozzle 50 and a plurality of main burner nozzles 60; and a tail cylinder 48 connected to the front end of the inner cylinder 47. That is, the burner liner 46 corresponds to a combustion part where the fuel F ejected from the main burner nozzles 60 and the pilot burner nozzle 50 burns.

[0043] As Figure 3 and Figure 4 shown, the pilot burner nozzle 50 is disposed along the central axis of the burner liner 46. And a plurality of main burner nozzles 60 are separated from each other and arranged along the circumferential direction so as to surround the outer peripheral side of the pilot burner nozzle 50.

[0044] As Figure 3 shown, the pilot burner nozzle 50 has: a pilot nozzle 54 connected to the fuel port 52; a pilot burner barrel 56 disposed so as to surround the pilot nozzle 54; and a plurality of swirlers (swirling plates) 58 provided on the outer periphery of the pilot nozzle 54.

[0045] The pilot nozzle 54 extends along the axial direction Da with the burner axis Ac as the center.

[0046] Here, one side of the axial direction Da which is the extension direction of the burner axis Ac and along the flow of the combustion gas and the upstream side is defined as the upstream side, and the other side and the downstream side along the flow of the combustion gas are defined as the downstream side. And the burner axis Ac is also the burner axis of this pilot burner nozzle 50 (central axis Axp: refer to Figure 5 described later).

[0047] An unillustrated injection hole for injecting the fuel F is formed at the downstream end of the pilot nozzle 54. A plurality of swirling plates 58 are provided on the upstream side of the position where the injection hole is formed in the pilot nozzle 54. Each swirling plate 58 is used to rotate the compressed air with the burner axis Ac as the center. Each swirling plate 58 extends from the outer periphery of the pilot nozzle 54 along a direction including a radial component and approaches the inner peripheral surface of the pilot burner barrel 56. The pilot burner barrel 56 has: a main body portion 56a located on the outer periphery of the pilot nozzle 54; and a tapered portion 56b connected to the downstream side of the main body portion 56a and gradually expanding in diameter toward the downstream side. A plurality of swirling plates 58 approach the inner peripheral surface of the main body portion 56a in the pilot burner barrel 56.

[0048] The main combustion burner 60 has: a main nozzle 64 connected to a fuel port 62; a main burner barrel 66 disposed so as to surround the main nozzle 64; an extension pipe 65 connecting the main burner barrel 66 to a burner liner 46 (such as an inner cylinder 47); and a swirler (rotating plate) 70 provided on the outer periphery of the main nozzle 64.

[0049] The main nozzle 64 is a rod-shaped nozzle extending along an axis direction Da with a burner axis Ab parallel to the burner axis Ac as the center. In addition, since the burner axis Ab of the main combustion burner 60 is parallel to the burner axis Ac, the axis direction Da related to the burner axis Ac and the axis direction Da related to the burner axis Ab are the same direction. Also, the upstream side of the axis direction Da related to the burner axis Ac is the upstream side of the axis direction Da related to the burner axis Ab, and the downstream side of the axis direction Da related to the burner axis Ac is the downstream side of the axis direction Da related to the burner axis Ab.

[0050] An injection hole for injecting fuel F is formed in the middle part in the axis direction Da of the main nozzle 64. A plurality of rotating plates 70 are provided near the position where the injection hole is formed in the main nozzle 64. Each rotating plate 70 is used to rotate the compressed air around the burner axis Ab. Each rotating plate 70 extends from the outer periphery of the main nozzle 64 along a direction including a radial direction component and approaches the inner peripheral surface of the main burner barrel 66. The main burner barrel 66 is located on the outer periphery of the main nozzle 64.

[0051] In the burner 4 having the above structure, the compressed air generated by the compressor 2 is supplied from the chamber inlet 40a into the burner chamber 40, and then flows from the burner chamber 40 into the pilot burner barrel 56 and a plurality of main burner barrels 66 via the air passage 43.

[0052] In the pilot combustion burner 50, the fuel F ejected from the pilot nozzle 54 is ejected together with the compressed air from the downstream end of the pilot burner barrel 56. The fuel F undergoes diffusion combustion or premixed combustion in the burner liner 46.

[0053] That is, Figure 2 、 Figure 3 and Figure 4 the pilot combustion burner 50 shown is a diffusion combustion type or premixed combustion type fuel injector.

[0054] In the main combustion burner 60, compressed air and the fuel F ejected from the main nozzle 64 are mixed in the main burner barrel 66 to form a premixed gas PM. In the main combustion burner 60, the premixed gas PM is ejected from the downstream end of the extension pipe 65. The fuel F in the premixed gas PM undergoes premixed combustion in the burner liner 46.

[0055] That is, Figure 2, Figure 3 and Figure 4 the main combustion burner 60 shown in FIGS. Figure 3 and Figure 4 is a premixed combustion type fuel injector.

[0056] In addition, injection holes for injecting the fuel F may be formed in the rotary plate 70, and the fuel F may be injected into the main burner tube 66 from there. At this time, the portion corresponding to the rod-shaped main nozzle 64 described above constitutes a hub rod, and the main nozzle is formed to have the hub rod and a plurality of rotary plates 70. The fuel F from the outside is supplied into the hub rod, and the fuel F is supplied from the hub rod to the rotary plate 70.

[0057] (Regarding the fuel F)

[0058] In the burner 4 according to several embodiments, it is configured to be able to use natural gas and hydrogen as the fuel F, for example, in the same manner as a conventional burner. In addition, in the following description, the natural gas as the fuel F is referred to as natural gas fuel FN or simply natural gas. Similarly, in the following description, the hydrogen as the fuel F is referred to as hydrogen fuel FH or simply hydrogen.

[0059] And, in the following description, when it is not necessary to particularly distinguish between the natural gas fuel FN, the hydrogen fuel FH, and the mixed fuel FM of the natural gas fuel FN and the hydrogen fuel FH, or when these fuels are collectively referred to, it is called the fuel F.

[0060] (Schematic of the structure of the pilot nozzle 54)

[0061] Figure 5 FIG. Figure 5 is a schematic diagram showing the structure near the front end of the pilot nozzle 54 in the burner 4 according to several embodiments and the schematic diagram of the supply system 200 for supplying the fuel F and the water W to the pilot nozzle 54.

[0062] Figure 5 The cross-sectional view of the pilot nozzle 54 shown in FIGS. to Figure 5 shows a cross-section of the pilot nozzle 54 along the central axis Axp (burner axis Ac).

[0063] The pilot nozzle 54 according to several embodiments may have at least one first injection hole 101, at least one second injection hole 102, and at least one third injection hole 103. In addition, in the pilot nozzle 54 shown in FIGS. Figure 5 and , a plurality of the first injection holes 101 and the third injection holes 103 are provided at intervals in the circumferential direction of the pilot nozzle 54 centered on the central axis Axp, and one second injection hole 102 is provided on the central axis Axp. Figure 5 In the pilot nozzle 54 shown in FIGS. Figure 5 and , a plurality of the first injection holes 101 and the third injection holes 103 are provided at intervals in the circumferential direction of the pilot nozzle 54 centered on the central axis Axp, and one second injection hole 102 is provided on the central axis Axp.

[0064] In the pilot nozzle 54 according to several embodiments, each first injection hole 101 is arranged on the radially outer side with respect to the third injection hole 103 and the second injection hole 102 around the central axis Axp, and as will be described later, is configured to be able to inject the fuel F or the mixture FW of the fuel F and water W injected from each first injection hole 101 obliquely outward in the radial direction.

[0065] In the pilot nozzle 54 according to several embodiments, as will be described later, each second injection hole 102 is configured to inject while diffusing the water W injected from the second injection hole 102 radially outward.

[0066] In the pilot nozzle 54 according to several embodiments, each third injection hole 103 is arranged on the radially inner side with respect to the first injection hole 101 and on the radially outer side with respect to the second injection hole 102, and as will be described later, is configured to be able to inject the water W injected from each third injection hole 103 obliquely inward in the radial direction.

[0067] In the pilot nozzle 54 according to several embodiments, a first flow path 111 for supplying the fuel F or the mixture FW of the fuel F and water W to each first injection hole 101 is formed. In the pilot nozzle 54 according to several embodiments, the first flow path 111 may be a single annular flow path having a circular ring shape in a cross section orthogonal to the central axis Axp, or may be a plurality of flow paths extending along the extending direction (axial direction) of the central axis Axp and formed at intervals in the circumferential direction around the central axis Axp.

[0068] In the pilot nozzle 54 according to several embodiments, a second flow path 112 for supplying the water W to the second injection hole 102 is formed. In the pilot nozzle 54 according to several embodiments, the second flow path 112 is a flow path extending along the axial direction at the central position in the radial direction.

[0069] In the pilot nozzle 54 according to several embodiments, a third flow path 113 for supplying the water W to each third injection hole 103 is formed. In the pilot nozzle 54 according to several embodiments, the third flow path 113 may be a single annular flow path having a circular ring shape in a cross section orthogonal to the central axis Axp, or may be a plurality of flow paths extending along the axial direction and formed at intervals in the circumferential direction around the central axis Axp.

[0070] (Regarding the supply system 200)

[0071] The gas turbine 1 according to several embodiments includes Figure 5 the supply system 200 shown. Figure 5The shown supply system 200 has: a fuel supply pipeline 211 for supplying fuel F to the first flow path 111 of the pilot nozzle 54; a first water supply pipeline 221 for supplying water W to the first flow path 111; a second water supply pipeline 222 for supplying water W to the second flow path 112 of the pilot nozzle 54; and a third water supply pipeline 223 for supplying water W to the third flow path 113 of the pilot nozzle 54.

[0072] Figure 5 In the shown supply system 200, a natural gas supply pipeline 213 and a hydrogen supply pipeline 215 are connected to the fuel supply pipeline 211 at a confluence part 217. The natural gas supply pipeline 213 is used to supply natural gas fuel FN from a supply source 201 of the natural gas fuel FN to the fuel supply pipeline 211, and the hydrogen supply pipeline 215 is used to supply hydrogen fuel FH from a supply source 202 of the hydrogen fuel FH to the fuel supply pipeline 211.

[0073] Figure 5 The shown supply system 200 has: a natural gas regulating valve 241 provided in the natural gas supply pipeline 213 to regulate the flow rate of the natural gas fuel FN supplied to the fuel supply pipeline 211; and a hydrogen regulating valve 242 provided in the hydrogen supply pipeline 215 to regulate the flow rate of the hydrogen fuel FH supplied to the fuel supply pipeline 211.

[0074] Figure 5 The shown supply system 200 has a water supply pipeline 224 for supplying water W from a supply source 203 of the water W to the first water supply pipeline 221, the second water supply pipeline 222, and the third water supply pipeline 223.

[0075] A first water regulating valve 243 is provided in the first water supply pipeline 221 to regulate the flow rate of the water W supplied to the first flow path 111 of the pilot nozzle 54. The downstream end of the first water supply pipeline 221 is connected to the fuel supply pipeline 211 at a confluence part 218 on the downstream side of the confluence part 217.

[0076] A second water regulating valve 244 is provided in the second water supply pipeline 222 to regulate the flow rate of the water W supplied to the second flow path 112 of the pilot nozzle 54.

[0077] A third water regulating valve 245 is provided in the third water supply pipeline 223 to regulate the flow rate of the water W supplied to the third flow path 113 of the pilot nozzle 54.

[0078] The natural gas regulating valve 241, the hydrogen regulating valve 242, the first water regulating valve 243, the second water regulating valve 244, and the third water regulating valve 245 are controlled by a controller configured to control these respective regulating valves. In several embodiments, the controller is implemented by the combustion control device 140 of the gas turbine 1.

[0079] Each processing function of the combustion control device 140 is constituted by software (computer program) and executed by a computer, but it is not limited thereto and may also be constituted by hardware.

[0080] In the gas turbine 1 according to several embodiments, the fuel F in the first flow path 111 supplied to the pilot nozzle 54 is natural gas fuel FN, a mixed fuel FM of natural gas fuel FN and hydrogen fuel FH, or hydrogen fuel FH. That is, the hydrogen co-firing rate in the pilot burner 50 is 0% or more and 100% or less. The hydrogen co-firing rate in the pilot burner 50 is controlled by adjusting the opening degrees of the natural gas regulating valve 241 and the hydrogen regulating valve 242 by the combustion control device 140.

[0081] In addition, although detailed description is omitted, in the gas turbine 1 according to several embodiments, it is configured to be able to burn natural gas fuel FN and a mixed fuel FM of natural gas fuel FN and hydrogen fuel FH also in each main burner 60. In addition, the upper limit value of the hydrogen co-firing rate in each main burner 60 is 100% or less.

[0082] In the following description, the operation in a state where the proportion of hydrogen fuel FH in the fuel F injected from the pilot burner 50, that is, the hydrogen co-firing rate (calorie ratio), is equal to or less than a specified value th is referred to as low hydrogen co-firing rate operation, and the operation in a state where the hydrogen co-firing rate in the pilot burner 50 exceeds the specified value th is referred to as high hydrogen co-firing rate operation.

[0083] In addition, in the following description, the above-mentioned specified value th is set to 0%, but the above-mentioned specified value th may also exceed 0%.

[0084] In the gas turbine 1 according to several embodiments, it is possible to supply the pilot burner 50 with a second fuel F2 having a hydrogen fuel FH content rate (hereinafter, also referred to as hydrogen content rate) higher than that of the first fuel F1.

[0085] In addition, in the following description, the first fuel F1 is set to natural gas fuel FN, and the second fuel F2 is set to a mixed fuel FM of natural gas fuel FN and hydrogen fuel FH or hydrogen fuel FH. However, if the hydrogen content rate is lower than that of the second fuel F2, the first fuel F1 may contain hydrogen fuel FH.

[0086] (Regarding the supply of water W)

[0087] In the gas turbine 1 according to several embodiments, if the hydrogen co - firing rate is increased, the temperature of the flame rises and the generation amount of NO x tends to increase. Also, as the temperature of the flame rises, the metal temperature of the burner 4 rises, which may cause damage.

[0088] For example, in the gas turbine 1 according to several embodiments, if the hydrogen co - firing rate in the pilot burner 50 is increased, the metal temperature of the cone portion 56b rises and the cone portion 56b may be damaged.

[0089] Therefore, in the operation method of the gas turbine 1 according to several embodiments, water W is supplied to the pilot nozzle 54 and ejected from the pilot nozzle 54 in the following manner, thereby suppressing the flame temperature, suppressing the generation of NO x and suppressing the possibility of damage to the burner 4.

[0090] In the operation method of the gas turbine 1 according to several embodiments, when operating at a low hydrogen co - firing rate, the first fuel F1 is ejected from the first ejection hole 101.

[0091] That is, the combustion control device 140 adjusts the opening degrees of the natural gas regulating valve 241 and the hydrogen regulating valve 242 so that the first fuel F1 is ejected from the first ejection hole 101. Thus, the first fuel F1 is ejected from the first ejection hole 101 via the fuel supply line 211 and the first flow path 111 of the pilot nozzle 54.

[0092] In the operation method of the gas turbine 1 according to several embodiments, when operating at a high hydrogen co - firing rate, the second fuel F2 is ejected from the first ejection hole 101, and water W is ejected from the second ejection hole 102.

[0093] That is, the combustion control device 140 adjusts the opening degrees of the natural gas regulating valve 241 and the hydrogen regulating valve 242 so that the second fuel F2 is ejected from the first ejection hole 101. Thus, the second fuel F2 is ejected from the first ejection hole 101 via the fuel supply line 211 and the first flow path 111 of the pilot nozzle 54.

[0094] And the combustion control device 140 adjusts the opening degree of the second water regulating valve 244 so that water W is ejected from the second ejection hole 102. Thus, water W is ejected from the second ejection hole 102 via the second water supply line 222 and the second flow path 112 of the pilot nozzle 54.

[0095] In this way, in the operation method of the gas turbine 1 according to several embodiments, when operating at a high hydrogen co - firing rate, water W is ejected from the second ejection hole 102, thereby being able to suppress the flame temperature. Therefore, while being able to increase the hydrogen co - firing rate, the generation of NO x can be suppressed, and the possibility of damage to the burner 4 can be suppressed.

[0096] In the operation method of the gas turbine 1 according to several embodiments, in the case of performing high hydrogen co-firing rate operation, a mixture FW2 of a second fuel F2 and water W can be injected from the first injection hole 101, and water W can be injected from the second injection hole 102.

[0097] That is, the combustion control device 140 adjusts the opening degrees of the natural gas control valve 241, the hydrogen control valve 242, and the first water control valve 243 so as to inject the mixture FW2 of the second fuel F2 and water W from the first injection hole 101. Thus, the second fuel F2 and water W are mixed at the confluence portion 218, and the mixture FW2 of the second fuel F2 and water W is injected from the first injection hole 101 via the fuel supply pipe 211 and the first flow path 111 of the pilot nozzle 54.

[0098] Moreover, the combustion control device 140 adjusts the opening degree of the second water control valve 244 so as to inject water W from the second injection hole 102. Thus, water W is injected from the second injection hole 102 via the second water supply pipe 222 and the second flow path 112 of the pilot nozzle 54.

[0099] Thereby, the flame temperature can be further suppressed.

[0100] In the operation method of the gas turbine 1 according to several embodiments, in the case of performing high hydrogen co-firing rate operation, as the hydrogen content rate of the second fuel F2 becomes higher, at least one of the injection amount of water W injected from the first injection hole 101 or the injection amount of water W injected from the second injection hole 102 can be increased.

[0101] That is, when injecting the mixture FW2 of the second fuel F2 and water W from the first injection hole 101, the combustion control device 140 adjusts the opening degrees of the natural gas control valve 241, the hydrogen control valve 242, and the first water control valve 243 so that the opening degree of the first water control valve 243 increases as the opening degree of the hydrogen control valve 242 increases.

[0102] Moreover, when injecting water W from the second injection hole 102, the combustion control device 140 adjusts the opening degree of the second water control valve 244 so as to, instead of increasing the opening degree of the first water control valve 243 as the opening degree of the hydrogen control valve 242 increases as described above, or simultaneously with increasing the opening degree of the first water control valve 243 as the opening degree of the hydrogen control valve 242 increases, increase the opening degree of the second water control valve 244 as the opening degree of the hydrogen control valve 242 increases.

[0103] Thereby, in the case of performing high hydrogen co-firing rate operation, as the hydrogen content rate of the second fuel F2 becomes higher, at least one of the injection amount of water W injected from the first injection hole 101 or the injection amount of water W injected from the second injection hole 102 can be increased.

[0104] Thus, by increasing the injection amount of water W, it is possible to suppress the temperature of the flame that rises as the hydrogen content of the second fuel F2 increases.

[0105] In the operation method of the gas turbine 1 according to several embodiments, when shifting from low hydrogen co-firing rate operation to high hydrogen co-firing rate operation, the first fuel F1 can be injected from the first injection hole 101, and then, a mixture FW1 of the first fuel F1 and water W can be injected from the first injection hole 101, and then, a mixture FW2 of the second fuel F2 and water W can be injected from the first injection hole 101.

[0106] That is, when shifting from low hydrogen co-firing rate operation to high hydrogen co-firing rate operation, the combustion control device 140 adjusts the opening degrees of the natural gas regulating valve 241 and the hydrogen regulating valve 242 so as to inject the first fuel F1 from the first injection hole 101. Thus, the first fuel F1 is injected from the first injection hole 101 via the fuel supply pipe 211 and the first flow path 111 of the pilot nozzle 54.

[0107] Next, the combustion control device 140 adjusts the opening degrees of the natural gas regulating valve 241, the hydrogen regulating valve 242, and the first water regulating valve 243 so as to inject a mixture FW1 of the first fuel F1 and water W from the first injection hole 101. Thus, the first fuel F1 and water W are mixed at the confluence part 218, and the mixture FW1 of the first fuel F1 and water W is injected from the first injection hole 101 via the fuel supply pipe 211 and the first flow path 111 of the pilot nozzle 54.

[0108] Next, the combustion control device 140 adjusts the opening degrees of the natural gas regulating valve 241, the hydrogen regulating valve 242, and the first water regulating valve 243 so as to inject a mixture FW2 of the second fuel F2 and water W from the first injection hole 101. Thus, the second fuel F2 and water W are mixed at the confluence part 218, and the mixture FW2 of the second fuel F2 and water W is injected from the first injection hole 101 via the fuel supply pipe 211 and the first flow path 111 of the pilot nozzle 54.

[0109] Thus, it is possible to suppress the flame temperature by starting to inject water W before shifting to high hydrogen co-firing rate operation.

[0110] In the operation method of the gas turbine 1 according to several embodiments, when shifting from low hydrogen co-firing rate operation to high hydrogen co-firing rate operation, a mixture FW1 of the first fuel F1 and water W can be injected from the first injection hole 101, and then, water W can be injected from the second injection hole 102.

[0111] That is, when shifting from low hydrogen co - firing rate operation to high hydrogen co - firing rate operation, the combustion control device 140 adjusts the opening degrees of the natural gas regulating valve 241, the hydrogen regulating valve 242, and the first water regulating valve 243 to inject a mixture FW1 of the first fuel F1 and water W from the first injection hole 101. Thus, the first fuel F1 and water W are mixed at the confluence part 218, and the mixture FW1 of the first fuel F1 and water W is injected from the first injection hole 101 via the fuel supply pipe 211 and the first flow path 111 of the pilot nozzle 54.

[0112] Next, the combustion control device 140 adjusts the opening degree of the second water regulating valve 244 to inject water W from the second injection hole 102. Thus, water W is injected from the second injection hole 102 via the second water supply pipe 222 and the second flow path 112 of the pilot nozzle 54.

[0113] Thus, it is possible to suppress the excessive injection of water W by sequentially performing the injection of the mixture FW1 of the first fuel F1 and water W from the first injection hole 101 and the injection of water W from the second injection hole 102.

[0114] In the operation method of the gas turbine 1 according to several embodiments, when performing high hydrogen co - firing rate operation, water W can be injected from the second injection hole 102 and water W can be injected from the third injection hole 103.

[0115] That is, when performing high hydrogen co - firing rate operation, the combustion control device 140 adjusts the opening degree of the second water regulating valve 244 to inject water W from the second injection hole 102. Thus, water W is injected from the second injection hole 102 via the second water supply pipe 222 and the second flow path 112 of the pilot nozzle 54.

[0116] Moreover, when performing high hydrogen co - firing rate operation, the combustion control device 140 adjusts the opening degree of the third water regulating valve 245 to inject water W from the third injection hole 103. Thus, water W is injected from the third injection hole 103 via the third water supply pipe 223 and the third flow path 113 of the pilot nozzle 54.

[0117] Thus, it is possible to further suppress the flame temperature by increasing the injection amount of water W.

[0118] In the pilot nozzle 54 according to several embodiments, the first injection hole 101 is arranged on the radially outer side of the pilot nozzle 54 centered on the central axis Axp and closer to the second injection hole 102.

[0119] Thus, it is possible to further suppress the flame temperature while ensuring flame stability.

[0120] In the gas turbine 1 according to several embodiments, the second fuel F2 is obtained by mixing hydrogen fuel FH and the first fuel F1.

[0121] That is, in the gas turbine 1 according to several embodiments, as Figure 5 shown, it is possible to mix the hydrogen fuel FH and the natural gas fuel FN as the first fuel F1 in the confluence section 217 to obtain the second fuel F2.

[0122] Thus, the second fuel can be easily obtained.

[0123] In the gas turbine 1 according to several embodiments, a fuel supply pipe 211 serving as a fuel flow path for supplying the second fuel F2 to the first injection hole 101 is connected to the pilot nozzle 54. When a mixture FW2 of the second fuel F2 and water W is injected from the first injection hole 101, the water W and the second fuel F2 flowing through the fuel supply pipe 211 serving as a fuel flow path can be mixed.

[0124] That is, in the gas turbine 1 according to several embodiments, as Figure 5 shown, it is configured to be able to supply water W to the fuel supply pipe 211 at a confluence section 218 on the downstream side of the confluence section 217 where the natural gas fuel FN from the supply source 201 of the natural gas fuel FN and the hydrogen fuel FH from the supply source 202 of the hydrogen fuel FH are mixed.

[0125] Thus, by mixing the water W and the second fuel F2 immediately before injecting the mixture FW2 of the second fuel F2 and water W, it is possible to inject while maintaining the state where the water W is dispersed in the second fuel F2.

[0126] In the gas turbine 1 according to several embodiments, the burner 4 includes a pilot nozzle 54 and a main nozzle 64.

[0127] According to the gas turbine 1 according to several embodiments, it is possible to suppress the flame temperature while burning the fuel F containing hydrogen in the pilot nozzle 54.

[0128] The present invention is not limited to the above embodiments, and also includes modified forms of the above embodiments or forms obtained by appropriately combining these forms.

[0129] For example, in the operation method of the gas turbine 1 according to several embodiments, when water W is injected from the second injection hole 102, water W can be injected from the third injection hole 103 instead of injecting water W from the second injection hole 102, and when water W is injected from the third injection hole 103, water W can be injected from the second injection hole 102 instead of injecting water W from the third injection hole 103.

[0130] In the operation method of the gas turbine 1 involved in the above several embodiments, when performing high hydrogen co-firing rate operation, the second fuel F2 can be injected only from a part of the first injection holes 101 among the plurality of first injection holes 101, and a mixture FW2 of the second fuel F2 and water W can be injected from the remaining first injection holes 101.

[0131] The content described in the above embodiments can be understood as follows, for example.

[0132] (1) The operation method of the gas turbine 1 according to at least one embodiment of the present invention is an operation method of a gas turbine 1 having a burner 4 that can use hydrogen and a fuel other than hydrogen as fuel. The burner 4 is provided with a nozzle (pilot nozzle 54) having at least one first injection hole 101 and at least one second injection hole 102. In the operation method of the gas turbine 1 according to at least one embodiment of the present invention, when performing low hydrogen co-firing rate operation, the first fuel F1 is injected from at least one first injection hole 101, and when performing high hydrogen co-firing rate operation in which the hydrogen co-firing rate is higher than the low hydrogen co-firing rate operation, the second fuel F2 having a higher hydrogen content rate than the first fuel F1 is injected from at least one first injection hole 101, and water W is injected from at least one second injection hole 102.

[0133] According to the method in the above (1), when performing high hydrogen co-firing rate operation, water W is injected from the second injection hole 102, whereby the flame temperature can be suppressed, so that the hydrogen co-firing rate can be increased while suppressing the generation of NOx, and the possibility of damage to the burner 4 can be suppressed.

[0134] (2) In several embodiments, in the method in the above (1), when performing high hydrogen co-firing rate operation, a mixture FW2 of the second fuel F2 and water W can be injected from at least one first injection hole 101, and water W can be injected from at least one second injection hole 102.

[0135] According to the method in the above (2), the flame temperature can be further suppressed.

[0136] (3) In several embodiments, in the method in the above (1) or (2), at least one first injection hole 101 can be arranged radially outside the at least one second injection hole 102 with respect to the center axis Axp of the nozzle (pilot nozzle 54).

[0137] According to the method in the above (3), the flame stability can be ensured while further suppressing the flame temperature.

[0138] (4) In several embodiments, in any one of the methods (1) to (3) above, when performing high hydrogen co - combustion rate operation, as the hydrogen content rate of the second fuel F2 becomes higher, at least one of the injection amount of water W injected from at least one first injection hole 101 or the injection amount of water W injected from at least one second injection hole 102 can be made larger.

[0139] According to the method in (4) above, it is possible to suppress the temperature of the flame that rises as the hydrogen content of the second fuel F2 increases by increasing the injection amount of water W.

[0140] (5) In several embodiments, in the method in (2) above, when transferring from low hydrogen co - combustion rate operation to high hydrogen co - combustion rate operation, the first fuel F1 can be injected from at least one first injection hole 101, then, a mixture FW1 of the first fuel F1 and water W can be injected from at least one first injection hole 101, and then, a mixture FW2 of the second fuel F2 and water W can be injected from at least one first injection hole 101.

[0141] According to the method in (5) above, it is possible to suppress the flame temperature by starting to inject water W before transferring to high hydrogen co - combustion rate operation.

[0142] (6) In several embodiments, in the method in (5) above, when transferring from low hydrogen co - combustion rate operation to high hydrogen co - combustion rate operation, a mixture FW1 of the first fuel F1 and water W can be injected from at least one first injection hole 101, and then, water W can be injected from at least one second injection hole 102.

[0143] According to the method in (6) above, it is possible to suppress the excessive injection of water W by sequentially performing the injection of the mixture FW1 of the first fuel F1 and water W from at least one first injection hole 101 and the injection of water W from at least one second injection hole 102.

[0144] (7) In several embodiments, in any one of the methods (1) to (6) above, the nozzle (pilot nozzle 54) can have at least one third injection hole 103. When performing high hydrogen co - combustion rate operation, water W can be injected from at least one second injection hole 102 and water W can be injected from at least one third injection hole 103.

[0145] According to the method in (7) above, it is possible to further suppress the flame temperature by increasing the injection amount of water W.

[0146] (8) In several embodiments, in any one of the methods (1) to (7) above, the second fuel F2 can be obtained by mixing hydrogen (hydrogen fuel FH) and the first fuel F1.

[0147] According to the method in (8) above, the second fuel F2 can be easily obtained.

[0148] (9) In several embodiments, in the method of (8) above, a fuel flow path (fuel supply pipe 211) for supplying a second fuel F2 to at least one first injection hole 101 may be connected to the nozzle (pilot nozzle 54). When a mixture FW2 of the second fuel F2 and water W is injected from at least one first injection hole 101, the water W and the second fuel F2 flowing through the fuel flow path (fuel supply pipe 211) may be mixed.

[0149] According to the method of (9) above, by mixing the water W and the second fuel F2 immediately before injecting the mixture FW2 of the second fuel F2 and water W, it is possible to inject while maintaining the state in which the water W is dispersed in the second fuel F2.

[0150] (10) In several embodiments, in any one of the methods of (1) to (9) above, the burner 4 may include a nozzle (pilot nozzle 54) as the pilot nozzle 54 and a main nozzle 64.

[0151] According to the method of (10) above, it is possible to suppress the flame temperature while burning the fuel F containing hydrogen in the pilot nozzle 54.

[0152] Reference Signs

[0153] 1 - Gas turbine, 4 - Gas turbine burner (burner), 50 - Pilot burner, 54 - Pilot nozzle, 60 - Main burner, 64 - Main nozzle, 101 - First injection hole, 102 - Second injection hole, 103 - Third injection hole, 111 - First flow path, 112 - Second flow path, 113 - Third flow path, 140 - Combustion control device, 200 - Supply system, 211 - Fuel supply pipe.

Claims

1. A method for operating a gas turbine, the gas turbine having a burner capable of using hydrogen and a fuel other than hydrogen as fuel, in the method for operating the gas turbine, the burner has a nozzle having at least one first injection hole and at least one second injection hole, in the case of performing low hydrogen co-firing rate operation, a first fuel is injected from the at least one first injection hole, in the case of performing high hydrogen co-firing rate operation with a hydrogen co-firing rate higher than the low hydrogen co-firing rate operation, a second fuel having a higher hydrogen content rate than the first fuel is injected from the at least one first injection hole, and water is injected from the at least one second injection hole.

2. The method for operating a gas turbine according to claim 1, wherein in the case of performing the high hydrogen co-firing rate operation, a mixture of the second fuel and water is injected from the at least one first injection hole, and water is injected from the at least one second injection hole.

3. The method for operating a gas turbine according to claim 1 or 2, wherein the at least one first injection hole is disposed radially outside the at least one second injection hole with respect to the central axis of the nozzle.

4. The method for operating a gas turbine according to claim 1 or 2, wherein in the case of performing the high hydrogen co-firing rate operation, as the hydrogen content rate of the second fuel becomes higher, at least one of the injection amount of water injected from the at least one first injection hole or the injection amount of water injected from the at least one second injection hole becomes larger.

5. The method for operating a gas turbine according to claim 2, wherein in the case of transferring from the low hydrogen co-firing rate operation to the high hydrogen co-firing rate operation, the first fuel is injected from the at least one first injection hole, then, a mixture of the first fuel and water is injected from the at least one first injection hole, then, a mixture of the second fuel and water is injected from the at least one first injection hole.

6. The method for operating a gas turbine according to claim 5, wherein in the case of transferring from the low hydrogen co-firing rate operation to the high hydrogen co-firing rate operation, a mixture of the first fuel and water is injected from the at least one first injection hole, then, water is injected from the at least one second injection hole.

7. The method for operating a gas turbine according to claim 1 or 2, wherein the nozzle has at least one third injection hole, in the case of performing the high hydrogen co-firing rate operation, water is injected from the at least one second injection hole, and water is injected from the at least one third injection hole.

8. The method for operating a gas turbine according to claim 1 or 2, wherein the second fuel is obtained by mixing the hydrogen and the first fuel.

9. The method for operating a gas turbine according to claim 8, wherein a fuel flow path for supplying the second fuel to the at least one first injection hole is connected to the nozzle, in the case of injecting a mixture of the second fuel and water from the at least one first injection hole, water is mixed with the second fuel flowing through the fuel flow path.

10. The method for operating a gas turbine according to claim 1 or 2, wherein The burner includes the nozzle as a pilot nozzle and a main nozzle.

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