JP7285623B2 - GAS TURBINE COMBUSTOR AND GAS TURBINE INCLUDING THE SAME, AND COMBUSTION INSTALLATION CONTROL METHOD FOR GAS TURBINE COMBUSTOR - Google Patents

Description

The present invention relates to a gas turbine combustor, a gas turbine including the same, and a combustion oscillation suppression method for the gas turbine combustor.

During combustion in a gas turbine combustor (hereinafter sometimes simply referred to as "combustor"), pressure fluctuations may occur inside the combustor. Pressure fluctuations can then cause combustion oscillations in the combustor. Excessive combustion oscillations lead to combustor and gas turbine damage. Therefore, a technique for suppressing the combustion oscillation of the combustor is desired.

A technique described in Patent Document 1 is known as a technique for suppressing combustion oscillations in gas turbines. U.S. Pat. No. 6,200,000 describes a combustor with circumferentially arranged pilot fuel nozzles. More specifically, FIG. 1(b) described in Patent Document 1 describes a portion where the interval between a pair of adjacent pilot fuel nozzles is 90°.

Japanese Patent Application Laid-Open No. 11-294770 (especially see FIG. 1(b))

By the way, the present inventors have studied and found that if there is a portion where the distance between the pilot fuel nozzles is too wide, the combustion oscillation may still be large.

An object of at least one embodiment of the present invention is to provide a gas turbine combustor capable of suppressing combustion oscillations more sufficiently than conventional ones, a gas turbine equipped with the same, and a method for suppressing combustion oscillations in the gas turbine combustor. .

(1) A gas turbine combustor according to at least one embodiment of the present invention includes a first nozzle and a plurality of second nozzles circumferentially arranged to surround the first nozzle. wherein the first nozzle has n (n is an integer equal to or greater than 2) fuel injection holes arranged in the circumferential direction, and the plurality of fuel injection holes are adjacent in the circumferential direction; The angle difference θ [°] between a pair of the fuel injection holes is 0<n×θ/360<2, and the first nozzle has a fuel injection amount from one or more of the fuel injection holes is configured to inject fuel from all of the fuel injection holes such that the amount of fuel injected from one or more of the other fuel injection holes is different.

According to the configuration (1) above, it is possible to provide a deviation in the axial heat rate distribution of the flame in the combustion chamber. As a result, heat concentration can be avoided, and combustion oscillation of the combustor can be suppressed.

(2) In some embodiments, in the configuration of (1) above, the plurality of fuel injection holes constitute a first injection hole group including one or more of the fuel injection holes, and the first injection hole group. and a second injection hole group including one or more of the fuel injection holes other than the fuel injection hole to which the first injection hole group is connected, and the first nozzle is connected to the first injection hole group and supplies fuel to the first injection hole group. and a second fuel flow path provided independently from the first fuel flow path and connected to the second injection hole group for supplying fuel to the second injection hole group. and

According to the configuration (2) above, independent fuel amount control can be performed for each of the first injection hole group and the second injection hole group. As a result, it is possible to perform a flexible combustion oscillation avoidance operation according to the combustion state.

(3) In some embodiments, in the configuration of (1) or (2) above, the plurality of fuel injection holes include a first injection hole group including one or more of the fuel injection holes; and a second injection hole group including one or more fuel injection holes other than the fuel injection holes constituting the hole group, the size of the fuel injection holes included in the first injection hole group, and the The size of the included fuel injection holes is characterized by being different.

According to the configuration (3) above, it is possible to change the fuel injection amount in the circumferential direction without increasing the number of fuel passages, thereby avoiding concentration of heat generation. Therefore, it is possible to suppress the combustion vibration only by adjusting the diameter of the fuel injection hole.

(4) In some embodiments, in the configuration of any one of (1) to (3) above, the plurality of fuel injection holes include a first injection hole group including one or more of the fuel injection holes; and a second injection hole group including one or more fuel injection holes other than the fuel injection holes forming the first injection hole group, and a fuel injection amount from each of the combustion injection holes forming the first injection hole group. and the fuel injection amount from each of the combustion injection holes constituting the second injection hole group is different, and the fuel injection holes included in the first injection hole group are arranged continuously in the circumferential direction. and the fuel injection holes included in the second injection hole group are arranged continuously in the circumferential direction.

According to the above configuration (4), the size of the flame can be ensured by continuously arranging the fuel injection holes in the circumferential direction. As a result, it is possible to suppress the occurrence of positions where no flame exists in the circumferential positions, and to suppress pressure fluctuations. As a result, it is possible to suppress the occurrence of combustion oscillations caused by pressure fluctuations.

(5) In some embodiments, in the configuration of any one of (1) to (4) above, the plurality of fuel injection holes include a first injection hole group including one or more of the fuel injection holes; and a second injection hole group including one or more fuel injection holes other than the fuel injection holes forming the first injection hole group, and a fuel injection amount from each of the combustion injection holes forming the first injection hole group. , the amount of fuel injected from each of the combustion injection holes constituting the second injection hole group is different, and the portion occupied by the first injection hole group is located at both ends of the first injection hole group in the circumferential direction. The region is characterized by an angle difference θ2 [°] between the pair of arranged fuel injection holes of 80° or more.

According to the above configuration (5), it is possible to secure the circumferential length of the first injection hole group and secure the size of the flame caused by the combustion of the fuel injected from the first injection hole group. . As a result, it is possible to suppress the occurrence of positions where no flame exists in the circumferential positions, and to suppress pressure fluctuations. As a result, it is possible to suppress the occurrence of combustion oscillations caused by pressure fluctuations.

(6) In some embodiments, in the configuration of any one of (1) to (5) above, the plurality of fuel injection holes are arranged between any pair of fuel injection holes adjacent in the circumferential direction. They are arranged so that the angle difference θ [°] is 0.8≦n×θ/360≦1.2.

According to the configuration (6) above, it is possible to easily form a plurality of fuel injection holes, and to easily design the combustor.

(7) In some embodiments, in the configuration of any one of (1) to (6) above, a plurality of the fuel injection holes are formed at equal intervals in the circumferential direction of the gas turbine combustor. Characterized by

According to the above configuration (7), combustion oscillation can be suppressed by changing the fuel injection amount in the circumferential direction.

(8) In some embodiments, in the configuration of any one of (1) to (7) above, the gas turbine combustor is configured to burn a mixed fuel of air and fuel. Characterized by

According to the above configuration (8), it is possible to suppress the combustion oscillation of the combustor even when using a mixed fuel that easily causes combustion oscillation.

(9) A gas turbine according to at least one embodiment of the present invention comprises the gas turbine combustor according to any one of (1) to (8) above, and a combustor for generating compressed air to be supplied to the combustor. and a turbine driven by combustion gas generated in the gas turbine combustor.

With configuration (9) above, it is possible to provide a deviation in the axial heat rate distribution of the flame in the combustion chamber. As a result, heat concentration can be avoided, and combustion oscillation of the combustor can be suppressed. As a result, damage to the gas turbine due to combustion oscillations in the combustor can be suppressed.

(10) A method for suppressing combustion oscillations in a gas turbine combustor according to at least one embodiment of the present invention includes a first nozzle and a plurality of second nozzles circumferentially arranged to surround the first nozzle. wherein the first nozzle has n (n is an integer equal to or greater than 2) fuel injection holes arranged in the circumferential direction, and the plurality of The fuel injection holes are arranged such that an angle difference θ [°] between any pair of the fuel injection holes adjacent in the circumferential direction is 0<n×θ/360<2, and the first nozzle is The fuel is injected from all the fuel injection holes such that the amount of fuel injected from one or more of the fuel injection holes is different from the amount of fuel injected from the other one or more of the fuel injection holes.

With configuration (10) above, it is possible to provide a deviation in the axial heat rate distribution of the flame in the combustion chamber. As a result, heat concentration can be avoided, and combustion oscillation of the combustor can be suppressed.

According to at least one embodiment of the present invention, it is possible to provide a gas turbine combustor capable of suppressing combustion oscillations more sufficiently than before, a gas turbine including the same, and a method for suppressing combustion oscillations in the gas turbine combustor. .

1 is a schematic configuration diagram showing a gas turbine according to one embodiment of the present invention; FIG. 1 is a schematic diagram of a combustor according to an embodiment of the invention; FIG. 1 is a schematic diagram showing a combustor according to an embodiment of the present invention, showing an enlarged view of the vicinity of the combustor; FIG. FIG. 3 is a cross-sectional view of the vicinity of the first combustion burner in the combustor according to one embodiment of the present invention; FIG. 4 is a plan view of a swirler in the combustor according to one embodiment of the present invention; FIG. 5 is a cross-sectional view taken along line AA of FIG. 4; FIG. 4 is a diagram illustrating positions of fuel injection holes formed in a first combustion burner in the combustor according to one embodiment of the present invention; FIG. 4 is a diagram showing fuel flow paths connected to a first combustion burner in a combustor according to one embodiment of the present invention; 4 is a graph showing the relationship between the fuel injection ratio and the magnitude of combustion oscillation; FIG. 4 is a diagram showing fuel flow paths connected to a first combustion burner in a combustor according to two embodiments of the present invention;

Several embodiments of the present invention will now be described with reference to the accompanying drawings. However, the contents described as embodiments or the contents described in the drawings below are merely examples, and can be arbitrarily changed and implemented without departing from the scope of the present invention. Moreover, each embodiment can be implemented by combining two or more arbitrarily. Furthermore, in each embodiment, common members are denoted by the same reference numerals, and overlapping descriptions are omitted for simplification of description.

In addition, the dimensions, materials, shapes, relative arrangements, etc. of components described as embodiments or shown in the drawings are not meant to limit the scope of the present invention, but are merely illustrative examples. do not have.
For example, expressions denoting relative or absolute arrangements such as "in a direction", "along a direction", "parallel", "perpendicular", "center", "concentric" or "coaxial" are strictly not only represents such an arrangement, but also represents a state of relative displacement with a tolerance or an angle or distance to the extent that the same function can be obtained.
For example, expressions such as "identical", "equal", and "homogeneous", which express that things are in the same state, not only express the state of being strictly equal, but also have tolerances or differences to the extent that the same function can be obtained. It shall also represent the existing state.
For example, expressions that express shapes such as squares and cylinders do not only represent shapes such as squares and cylinders in a geometrically strict sense. The shape including the part etc. shall also be represented.
On the other hand, the expressions "comprising", "comprising", "having", "including", or "having" one component are not exclusive expressions excluding the presence of other components.

FIG. 1 is a schematic configuration diagram showing a gas turbine 100 according to one embodiment of the present invention. As shown in FIG. 1, a gas turbine 100 according to one embodiment includes a compressor 2 for generating compressed air as an oxidant supplied to a combustor 4, and a combustion gas using the compressed air and fuel. A combustor 4 (gas turbine combustor) for generating and a turbine 6 configured to be driven by the combustion gases produced in the combustor 4 . In the case of the gas turbine 100 for power generation, a generator (not shown) is connected to the turbine 6 and the rotational energy of the turbine 6 is used to generate power.

The compressor 2 is provided on the compressor casing 10, the inlet side of the compressor casing 10, and passes through both the compressor casing 10 and the turbine casing 22 (to be described later) as well as an air intake port 12 for taking in air. and various blades arranged in the compressor casing 10 . The various blades are an inlet guide blade 14 provided on the air intake port 12 side, a plurality of stationary blades 16 fixed on the compressor casing 10 side, and a rotor arranged alternately with respect to the stationary blades 16. a plurality of rotor blades 18 implanted in 8; Note that the compressor 2 may include other components such as an air bleed chamber (not shown). In such a compressor 2, air taken in from the air intake port 12 passes through the plurality of stationary blades 16 and the plurality of rotor blades 18 and is compressed into high-temperature, high-pressure compressed air. Then, the high-temperature and high-pressure compressed air is sent from the compressor 2 to the combustor 4 in the latter stage.

Combustor 4 is disposed within casing 20 . Although only one is shown in FIG. 1 , a plurality of combustors 4 are annularly arranged around the rotor 8 in the casing 20 . The combustor 4 is supplied with fuel and compressed air generated by the compressor 2 , and combusts the fuel to generate combustion gas, which is a working fluid for the turbine 6 . The combustion gas is then sent from the combustor 4 to the downstream turbine 6 .

The turbine 6 includes a turbine casing 22 and various blades arranged within the turbine casing 22 . Various blades include a plurality of stationary blades 24 fixed to the turbine casing 22 side and a plurality of moving blades 26 implanted in the rotor 8 so as to be alternately arranged with respect to the stationary blades 24. . Note that the turbine 6 may include other components such as outlet guide vanes (not shown). In the turbine 6 , the combustion gas passes through the plurality of stationary blades 24 and the plurality of moving blades 26 to rotate the rotor 8 . This drives a generator (not shown) connected to the rotor 8 .

An exhaust chamber 30 is connected to the downstream side of the turbine casing 22 via an exhaust casing 28 . The combustion gas after driving the turbine 6 is discharged to the outside through the exhaust vehicle chamber 28 and the exhaust chamber 30 .

FIG. 2 is a schematic diagram showing a combustor 4 according to one embodiment of the invention. Since FIG. 2 is a schematic diagram, the structure shown in FIG. 2 is partially different from the structure shown in FIG. 3 which will be described later. The combustor 4 includes a combustor liner 46 provided in a combustor casing 40 defined by the casing 20, and a first combustion burner 50 and a plurality of second combustion burners 60 respectively arranged in the combustor liner 46. ,including. Further, below the combustor casing 40 is formed a casing inlet 42 for taking in the high-temperature, high-pressure compressed air generated by the compressor 2 (see FIG. 1) into the combustor casing 40 . Note that the combustor 4 may include other components such as a bypass pipe (not shown) for bypassing the combustion gas.

The combustor liner 46 has an inner cylinder 46a arranged around the first combustion burner 50 and the plurality of second combustion burners 60, and a transition piece 46b connected to the tip of the inner cylinder 46a. . A first combustion burner 50 is positioned along the central axis of combustor liner 46 .

FIG. 3 is a schematic diagram showing the combustor 4 according to one embodiment of the present invention, and is an enlarged view showing the vicinity of the combustor 4. As shown in FIG. The first combustion burner 50 is, for example, a burner for burning diffusion fuel supplied through a diffusion fuel passage (not shown) to generate a diffusion combustion flame. The first combustion burner 50 also burns premixed fuel (premixed gas) from a swirler 58 to generate a combustion flame, although the details will be described later. The first combustion burner 50 includes a first nozzle 54 connected to fuel ports 52a and 52b, a cone 56 arranged to surround the first nozzle 54, and a swirler 58 provided on the outer periphery of the first nozzle 54. , provided. The first nozzle 54 is, for example, a nozzle for injecting diffusion fuel and premixed fuel.

The fuel port 52a is connected to a first fuel flow path 83 described with reference to FIG. Also, the fuel port 52b is connected to a second fuel flow path 85, which will also be described with reference to FIG. Both the first fuel flow path 83 and the second fuel flow path 85 are provided in the first nozzle 54 and connected to the swirler 58 formed in the first combustion burner 50 .

The second combustion burner 60 is, for example, a burner for burning premixed gas. The second combustion burner 60 includes a second nozzle 63 connected to the fuel port 62, a burner cylinder 66 arranged to surround the second nozzle 63, a swirler 70 provided on the outer circumference of the second nozzle 63, Prepare. The second nozzle 63 is a nozzle for injecting premixed fuel, for example. In the circumferential direction of the first nozzle 54 , eight (a plurality of) second nozzles 63 are spaced apart from each other so as to surround the first nozzle 54 . Note that only two second nozzles 63 are shown in FIG.

In the combustor 4, the high-temperature, high-pressure compressed air generated by the compressor 2 is supplied into the combustor casing 40 from the casing inlet 42 (see FIG. 2). The compressed air that has flowed into the combustor casing 40 and the fuel injected from the swirler 58 of the first combustion burner 50 through the fuel ports 52 a and 52 b are mixed in the cone 56 . Then, the mixed fuel is ignited by a pilot flame (not shown) and combusted to generate combustion gas. The combustion gas is then swirled by the swirler 58 and flows into the combustor liner 46 . Then, part of the combustion gas diffuses to the surroundings with flame. As a result, the mixed fuel that has flowed into the combustor liner 46 from the second combustion burner 60 is ignited and combusted.

FIG. 4 is a cross-sectional view of the vicinity of the first combustion burner 50 in the combustor 4 according to one embodiment of the present invention. For simplification of illustration, diffusion fuel injection holes for injecting diffusion fuel from the first nozzle 54 are not shown. Eight swirlers 58 (only two are shown in FIG. 4) are formed around the first nozzle 54 so as to protrude outward from the outer peripheral surface of the first nozzle 54 . Inside the swirler 58, an inner space 84 is formed that is connected to the first fuel flow path 83 or the second fuel flow path 85, respectively. Further, the swirler 58 is formed with a fuel injection hole 59 (see FIG. 7, not shown in FIG. 4) communicating with the inner space 84 respectively.

Here, as described above, the first fuel flow path 83 is connected to the fuel port 52a. Therefore, the fuel supplied to the inner space 84 of the swirler 58 through the fuel port 52 a and the first fuel flow path 83 is injected through the fuel injection holes 59 formed in the swirler 58 . Also, the second fuel flow path 85 is connected to the fuel port 52b. Therefore, the fuel supplied to the inner space 84 of the swirler 58 through the fuel port 52b and the second fuel flow path 85 is also injected through the fuel injection holes 59 formed in the swirler 58 . The injected fuel is then mixed with the compressed air in the air flow path 34 and combusted.

The fuel combusted in combustor 4 is a mixture of compressed air (a form of air) and fuel. That is, the combustor 4 is configured to burn a mixed fuel of air and fuel. Although the details will be described later, in the gas turbine 100, the combustion oscillation of the combustor 4 is sufficiently suppressed. Therefore, even when a mixed fuel that easily causes combustion oscillation is used, the combustion oscillation of the combustor 4 can be suppressed.

FIG. 5 is a front view of the swirler 58 in the combustor 4 according to one embodiment of the invention. The swirler 58 has a streamlined shape in plan view. By disposing the swirler 58 having such a shape around the outer periphery of the first nozzle 54, the compressed air flowing through the air passage 34 (see FIG. 4) formed between the first nozzle 54 and the cone 56 swirls. power is given. As a result, the compressed air becomes a swirling airflow and flows to the cone 56 .

The swirler 58 has a back surface 581 located on the side of the fuel port 52 (see FIG. 3) and an airfoil surface 582 located on the side of the combustor liner 46 (see FIG. 3). Of these, the back surface 581 and the blade pressure surface 582 are formed with fuel injection holes 59 penetrating in the thickness direction (however, the fuel injection holes 59 formed in the back surface 581 are not shown).

6 is a cross-sectional view taken along the line AA of FIG. 4. FIG. The eight swirlers 58 are arranged at regular intervals around the outer circumference of the first nozzle 54 . An inner space 84 is formed inside each swirler 58 to which either the first fuel flow path 83 or the second fuel flow path 85 is connected. Specifically, the inner spaces 84 of the five swirlers 58 located in the upper half (including the horizontal direction) of the eight swirlers 58 are connected to the first fuel flow paths 83 . On the other hand, the inner spaces 84 of the three swirlers 58 positioned in the lower half are connected to second fuel flow paths 85 provided independently from the first fuel flow paths 83 . As described above, the fuel flow path connected to the inner space 84 of the swirler 58 is different for each inner space 84, so that the fuel injection hole 59 (see FIG. 7, not shown in FIG. 6) communicating with the inner space 84 can be changed for each fuel injection hole 59 .

FIG. 7 is a diagram illustrating positions of fuel injection holes 59 formed in the first combustion burner 50 in the combustor 4 according to one embodiment of the present invention. In FIG. 7, the wing surfaces 582 of the eight swirlers 58 are illustrated. As shown in FIG. 7, the eight swirlers 58a, 58b, 58c, 58d, 58e, 58f, 58g and 58h have fuel injection holes 59a, 59b, 59c, 59d, 59e, 59f and 59g at their respective edges. , 59h are formed. Therefore, the first nozzle 54 has eight fuel injection holes 59 arranged in the circumferential direction via the swirler 58 . In the combustor 4 , as an example only, the eight fuel injection holes 59 are arranged at equal intervals on the same circumference around the point P, which is the axial center of the cylindrical first nozzle 54 .

The number n of fuel injection holes 59 is arbitrary, and is not limited to n=8 as described above. Therefore, the number n of fuel injection holes 59 may be arbitrarily determined as an integer in the range of 2 or more according to the number of swirlers 58 of two or more. Moreover, although the fuel injection hole 59 is provided in the first nozzle 54 via the swirler 58 as described above, the fuel injection hole 59 may be formed in a member other than the swirler 58, and the fuel injection hole 59 may be formed directly on the outer periphery of the first nozzle 54. Injection holes 59 may be formed.

In the combustor 4, the eight fuel injection holes 59 are arranged in the circumferential direction of the first nozzle 54 so that the angle difference θ (=360/n) between any pair of adjacent fuel injection holes 59 is n =8) [°] is arranged so that 0<n×θ/360<2. Specifically, as an example, the angle difference θ between any pair of adjacent fuel injection holes 59 is 45°. The angle difference θ between the pair of fuel injection holes 59a and 59b is the angle difference θ obtained by connecting the center of gravity of the fuel injection hole 59a, the point P, and the center of gravity of the fuel injection hole 59b. .

Although θ is not limited to 45° (when n=8) as described above, from the viewpoint of ease of designing the combustor 4, any pair of adjacent fuel injection holes 59 are preferably formed at regular intervals or close to regular intervals. Specifically, the lower limit of the range of θ is 0<n×θ/360, preferably 0.2≦n×θ/360, more preferably 0.4≦n×θ/360, as described above. , more preferably 0.6 ≤ n x θ/360, and particularly preferably 0.8 ≤ n x θ/360. Further, as the upper limit, as described above, n × θ/360 < 2, preferably n × θ/360 ≤ 1.8, more preferably n × θ/360 ≤ 1.6, still more preferably n × θ /360≦1.4, particularly preferably n×θ/360≦1.2. It is preferable that the angle difference θ between all adjacent fuel injection holes 59 among the fuel injection holes 59 of the combustor 4 satisfies the above range.

However, among θ that satisfies the above range, θ such that any pair of adjacent fuel injection holes 59 are equally spaced is preferable. Therefore, in the example shown in FIG. 7 (n=8), the angle difference .theta. between the pair of fuel injection holes 59a and 59b with respect to the point P is 45.degree. as described above. The angular difference θ between another pair of adjacent fuel injection holes 59 is also 45°. In this manner, a plurality of fuel injection holes 59 are formed at equal intervals in the circumferential direction of the combustor 4, so that the fuel injection amount can be changed in the circumferential direction, and combustion oscillation can be suppressed. However, the angle difference θ may differ between adjacent fuel injection holes 59 .

FIG. 8 is a diagram showing the first fuel flow path 83 and the second fuel flow path 85 connected to the first combustion burner 50 in the combustor 4 according to one embodiment of the invention. In FIG. 8, the first fuel flow path 83 and the second fuel flow path 85 are indicated by thick solid lines.

In the combustor 4, of the eight fuel injection holes 59, the upper half (including the horizontal direction) of the fuel injection holes 59a, 59b, 59c, 59d, and 59e that are continuously arranged in the circumferential direction receive the first fuel flow. A path 83 is connected. Therefore, the first fuel flow path 83 (also see FIG. 3) branches midway and is connected to each of the fuel injection holes 59a, 59b, 59c, 59d and 59e. A second fuel flow path 85 provided independently of the first fuel flow path 83 is connected to the lower half fuel injection holes 59f, 59g, and 59h that are similarly arranged continuously in the circumferential direction. . Therefore, the second fuel flow path 85 (also see FIG. 3) branches midway and is connected to each of the fuel injection holes 59f, 59g, and 59h.
Hereinafter, the fuel injection holes 59a, 59b, 59c, 59d, and 59e are collectively referred to as "first injection hole group 59A." Also, the fuel injection holes 59f, 59g, and 59h are collectively referred to as a "second injection hole group 59B".

Therefore, in the combustor 4, the first nozzle 54 is connected to the first injection hole group 59A, and the first fuel flow path 83 for supplying fuel to the first injection hole group 59A and the first fuel flow path 83 and a second fuel passage 85 provided independently from the second injection hole group 59B and connected to the second injection hole group 59B for supplying fuel to the second injection hole group 59B. Thus, by providing the two first fuel flow passages 83 and the second fuel flow passages 85, it is possible to control the amount of fuel independently for each of the first injection hole group 59A and the second injection hole group 59B. Become. As a result, it is possible to perform a flexible combustion oscillation avoidance operation according to the combustion state.

In the combustor 4 , five fuel injection holes 59 are connected to the first fuel flow path 83 and three fuel injection holes 59 are connected to the second fuel flow path 85 . Therefore, if the amount of fuel flowing through the first fuel flow path 83 and the amount of fuel flowing through the second fuel flow path 85 are set to be the same, the fuel injection hole 59 connected to the first fuel flow path 83 (first injection hole The amount of fuel injected from each of the groups 59A) is smaller than the amount of fuel injected from each of the fuel injection holes 59 (second injection hole group 59B) connected to the second fuel passage 85 . That is, in the first nozzle 54 of the fuel device 4 , the fuel injection amount from one or more fuel injection holes 59 is different from the fuel injection amount from the other one or more fuel injection holes 59 . Fuel is injected from all the fuel injection holes 59 .

Thus, in the combustor 4, while fuel is injected from all the fuel injection holes 59 provided in the first nozzle 54, the fuel injection amount from the first injection hole group 59A and the fuel injection amount from the second injection hole group 59B is different from the fuel injection amount of By doing so, it is possible to provide a deviation in the axial heat rate distribution of the flame in the combustor liner 46 (combustion chamber). That is, the flame position approaches the first nozzle 54 because the combustion speed increases as the fuel injection amount increases. On the other hand, when the fuel injection amount decreases, the combustion speed decreases, so the flame position moves away from the first nozzle 54 . As a result, heat concentration can be avoided, and combustion vibration of the combustor 4 can be suppressed.

Further, since the fuel injection holes 59 are continuously arranged in the circumferential direction in each of the first injection hole group 59A and the second injection hole group 59B, the fuel injection is continuously performed in the circumferential direction. can ensure the size of As a result, it is possible to suppress the occurrence of positions where no flame exists in the circumferential positions, and to suppress pressure fluctuations. As a result, it is possible to suppress the occurrence of combustion oscillations caused by pressure fluctuations.

The number of fuel injection holes 59 included in the first injection hole group 59A is not particularly limited as long as it is one or more. Also, the number of fuel injection holes 59 included in the second injection hole group 59B is not particularly limited as long as it is one or more. However, from the viewpoint of sufficiently ensuring the size of the flame caused by the combustion of the fuel injected from the fuel injection holes 59, the portions occupied by the first injection hole groups 59A are arranged at both ends in the circumferential direction of the first injection hole groups 59A. It is preferable that the angle difference θ2 [°] between the pair of fuel injection holes 59 is 80° or more. The angle difference θ2 is more preferably 90° or more, particularly preferably 120° or more. In the example shown in FIG. 8, the portion occupied by the first injection hole group 59A is 180° as the angle difference θ2 between the pair of fuel injection holes 59c and 59g arranged at both circumferential ends of the first injection hole group 59A. It is an area where

Thus, by setting the angle difference θ2 to 80° or more, the circumferential length of the first injection hole group 59A is ensured, and the flame caused by the combustion of the fuel injected from the first injection hole group 59A is prevented. can ensure the size of As a result, it is possible to suppress the occurrence of positions where no flame exists in the circumferential positions, and to suppress pressure fluctuations. As a result, it is possible to suppress the occurrence of combustion oscillations caused by pressure fluctuations.

Furthermore, in the example shown in FIG. 8, there are two injection holes: a first injection hole group 59A including fuel injection holes 59 with a small amount of fuel injection and a second injection hole group 59B including fuel injection holes 59 with a large amount of fuel injection. Although groups are shown, there may be three or more injection hole groups. That is, three or more injection hole groups including one or more fuel injection holes 59 each having the same fuel injection amount may be provided, and the fuel injection amount may be different for each injection hole group. If necessary, three or more fuel passages for supplying fuel to three or more injection hole groups can be provided. Even if the number of fuel injection holes 59 forming an injection hole group is only one, the term "injection hole group" will be used for convenience.

FIG. 9 is a graph showing the relationship between the fuel injection ratio R and the magnitude of combustion oscillation. This graph is a graph obtained by using the combustor 4 described above as a result of studies by the present inventors. However, the shape of this graph is only an example, and other shapes are not excluded. In the graph, the "fuel injection ratio R" on the horizontal axis represents the amount of fuel injected from each fuel injection hole 59 included in the first injection hole group 59A with respect to the amount of fuel injected from each fuel injection hole 59 of the combustor 4. It represents the ratio of the fuel injection amount.

The fuel injection ratio R is the number of fuel injection holes 59 forming the first injection hole group 59A (m _A =5 in the example _shown in FIG. 7), and the total number of fuel injection holes 59 of the first injection hole group 59A. _GA is the amount of fuel supplied to the second injection hole group 59B, _mB is the number of fuel injection holes forming the second injection hole group 59B ( _mB = 3 in the example shown in FIG. 7), and the fuel injection holes 59 of the second injection hole group 59B If the amount of fuel supplied to the whole is defined as _GB , it is represented by the following equation (1). _GA is the fuel flow rate in the first fuel flow path 83 (see FIG. 8). _GB is the fuel flow rate in the second fuel flow path 85 (see FIG. 8).

In the graph shown in FIG. 9, point A (R=0) represents a state in which fuel is not injected from each fuel injection hole 59 of the first injection hole group 59A. In this case, since G _A /m _A =0, R=0. Hereinafter, this state is referred to as "the first injection hole group 59A closed state". At point B (R=R ₁ ), the fuel injection amount from each fuel injection hole 59 of the first injection hole group 59A and the fuel injection amount from each fuel injection hole 59 of the second injection hole group 59B are Represents equality. In this case, since G _A /m _A =G _B /m _B , R=R ₁ =1. Hereinafter, this state will be referred to as a "uniform state". Furthermore, point C (R=R ₂ ) represents a state in which fuel is not injected from each fuel injection hole 59 of the second injection hole group 59B. In this case, G _B /m _B =0, so R=R ₂ =(m _A +m _B )/m _A . Hereinafter, this state will be referred to as "second injection hole group 59B closed state".

In this graph, in the closed state (point A) of the first injection hole group 59A, while the fuel injection amount from each fuel injection hole 59 of the second injection hole group 59B is kept constant, each fuel injection of the first injection hole group 59A When the injection of fuel from the hole 59 is started little by little (when R is started to be increased), the magnitude of the combustion oscillation becomes smaller. At this time, the difference between the fuel injection amount from each fuel injection hole 59 of the first injection hole group 59A and the fuel injection amount from each fuel injection hole 59 of the second injection hole group 59B gradually decreases. Become. Then, the magnitude of the combustion oscillation increases again at point D, reaching a uniform state (point B).

Next, from the uniform state (point B), while keeping the fuel injection amount from each fuel injection hole 59 of the first injection hole group 59A constant, the fuel from each fuel injection hole 59 of the second injection hole group 59B is When the injection amount is gradually decreased (when R is increased), the magnitude of combustion oscillation becomes smaller. At this time, the difference between the fuel injection amount from each fuel injection hole 59 of the first injection hole group 59A and the fuel injection amount from each fuel injection hole 59 of the second injection hole group 59B gradually increases. Become. Then, the magnitude of the combustion oscillation increases again at point E, and the second injection hole group 59B is closed (point C).

For example, the reason why the combustion oscillation is suppressed as shown in FIG. 9 is considered as follows. By injecting fuel from both the first injection hole group 59A and the second injection hole group 59B, it is possible to suppress the occurrence of portions where no flame is formed. In addition, by varying the amount of fuel, an intentional deviation in the axial heat rate distribution of the flame in the combustor liner 46 can be provided. As a result of studies by the inventors of the present invention, it is considered that these interactions can avoid heat concentration and sufficiently suppress combustion oscillation of the combustor 4 as shown in FIG. 9, for example.

In the example shown in FIG. 8, the magnitude of the fuel injection ratio R may be appropriately changed according to the operating conditions such as the properties of the fuel, the structure of the combustor 4, and the duration of operation. That is, by controlling at least one of the fuel amount supplied to the first injection hole group 59A or the second injection hole group 59B by controlling a fuel amount adjustment valve or the like (not shown) according to the actual driving situation, the fuel The injection amount can be adjusted. As a result, the fuel injection ratio R can be changed, and combustion fluctuations can be flexibly suppressed according to the actual driving conditions.

In the gas turbine 100 including the combustor 4 as described above, the combustion oscillation of the combustor 4 is suppressed as described above. Therefore, damage to the gas turbine 100 caused by combustion oscillation of the combustor 4 can be suppressed. Further, by using the combustor 4 described above, all the fuel injection holes 95 are arranged such that the fuel injection amount from one or more fuel injection holes 59 is different from the fuel injection amount from the other one or more fuel injection holes 59 . It is possible to provide a method for suppressing combustion oscillations in a combustor that can suppress combustion oscillations in the combustor 4 by injecting fuel from the .

Note that in the above example, attention is paid to the fuel injection hole 59 in the first combustion burner 50, but for example, attention is paid to two or more fuel injection holes (not shown) in the second combustion burner 60, and the fuel injection amount Deviations can be provided. Further, in the first combustion burner 50, in addition to injecting mixed fuel of compressed air and fuel, diffusion fuel is injected through diffusion fuel injection holes (not shown). Therefore, two or more diffusion fuel injection holes may be provided to provide a deviation in the injection amount of diffusion fuel.

In the above example, the fuel injection holes 59 of the combustor 4 are divided into two injection hole groups (first injection hole group 59A and second injection hole group 59B), and fuel injection from these two injection hole groups I changed the amount. However, for example, the fuel injection holes 59 of the combustor 4 are divided into three injection hole groups (first injection hole group, second injection hole group, and third injection hole group), and from these three injection hole groups The fuel injection amount may be changed. In this case, for example, the first injection hole group and the second injection hole group are considered as one separate group, and the fuel injection amount for the two groups, this separate group and the third injection hole group, is determined by the above method. should be determined. Then, based on the amount of fuel to be injected in another group, the fuel injection amounts of the first injection hole group and the second injection hole group constituting the other group may be determined. By these methods, it is possible to determine the fuel injection amount in the three injection hole groups (first injection hole group, second injection hole group, and third injection hole group). The same is true when there are four or more injection hole groups.

FIG. 10 is a diagram showing fuel flow paths connected to a first combustion burner 50A in a combustor (not shown) according to two embodiments of the present invention. In the example shown in FIG. 8 and the like, two independent fuel flow paths (first fuel flow path 83 and second fuel flow path 85) are provided for supplying fuel to the fuel injection hole 59. . However, in the combustor according to the second embodiment of the present invention, only the first fuel flow path 83 is provided and the second fuel flow path 85 is not provided. Then, as shown in FIG. 10 , the first fuel flow path 83 branches midway to supply fuel to eight fuel injection holes 59 .

As shown in FIG. 10, the size of the fuel injection holes 59 included in the first injection hole group 59A differs from the size of the fuel injection holes 59 included in the second injection hole group 59B. Specifically, the size of the fuel injection holes 59 included in the first injection hole group 59A is smaller than the size of the fuel injection holes 59 included in the second injection hole group 59B. As a result, the amount of fuel injected from each of the three combustion injection holes 59 forming the second injection hole group B is injected from each of the five combustion injection holes 59 forming the first injection hole group A. It is larger than the fuel injection amount.

By doing so, similarly to the combustor 4 described above with reference to FIG. 8, it is possible to change the fuel injection amount in the circumferential direction without increasing the number of fuel passages, thereby avoiding concentration of heat generation. Therefore, it is possible to suppress the combustion vibration only by adjusting the diameter of the fuel injection hole.

2 Compressor 4 Combustor 6 Turbine 8 Rotor 10 Compressor casing 12 Inlet 14 Inlet guide vanes 16, 24 Stator vanes 18, 26 Rotor blade 20 Casing 22 Turbine casing 28 Exhaust casing 30 Exhaust chamber 34 Air passage 40 Combustor casing Chamber 42 Chamber entrance 46a Inner cylinder 46b Transition piece 50, 50A First combustion burner 52, 62, 62a, 62b Fuel port 54 First nozzle 56 Cone 58, 58a, 58b, 58c, 58d, 58e, 58f, 58g, 58h , 70 swirler 59 fuel injection holes 59, 59a, 59b, 59c, 59d, 59e, 59f, 59g, 59h fuel injection holes 59A first injection hole group 59B second injection hole group 60 second combustion burner 63 second nozzle 66 burner Cylinder 83 First fuel channel 84 Inner space 85 Second fuel channel 100 Gas turbine 581 Rear surface 582 Blade ventral surface

Claims (11)

A gas turbine combustor comprising one cylindrical first nozzle and a plurality of second nozzles circumferentially arranged to surround the first nozzle,
The cylindrical first nozzle is configured to inject fuel from n (n is an integer equal to or greater than 2) fuel injection holes arranged in the circumferential direction so as to surround the axial center of the first nozzle. is ,
The n fuel injection holes are arranged such that an angle difference θ [°] between any pair of the fuel injection holes adjacent in the circumferential direction is 0<n×θ/360<2,
The first nozzle injects fuel from all of the fuel injection holes such that the amount of fuel injected from one or more of the fuel injection holes is different from the amount of fuel injected from the other one or more of the fuel injection holes. A gas turbine combustor, characterized in that it is configured to: The n fuel injection holes include a first injection hole group including one or more of the fuel injection holes, and a second injection hole including one or more of the fuel injection holes other than the fuel injection holes forming the first injection hole group. a group of pores;
The first nozzle is
a first fuel passage connected to the first injection hole group for supplying fuel to the first injection hole group;
A second fuel flow path provided independently from the first fuel flow path, connected to the second injection hole group, and supplying fuel to the second injection hole group, A gas turbine combustor according to claim 1 . The n fuel injection holes include a first injection hole group including one or more of the fuel injection holes, and a second injection hole including one or more of the fuel injection holes other than the fuel injection holes forming the first injection hole group. a group of pores;
3. The fuel injection hole according to claim 1, wherein the size of the fuel injection holes included in the first injection hole group and the size of the fuel injection holes included in the second injection hole group are different. Gas turbine combustor. The n fuel injection holes include a first injection hole group including one or more of the fuel injection holes, and a second injection hole including one or more of the fuel injection holes other than the fuel injection holes forming the first injection hole group. a group of pores;
The fuel injection amount from each of the fuel injection holes forming the first injection hole group is different from the fuel injection amount from each of the fuel injection holes forming the second injection hole group,
The fuel injection holes included in the first injection hole group are arranged continuously in the circumferential direction,
The gas turbine combustor according to any one of claims 1 to 3, wherein the fuel injection holes included in the second injection hole group are arranged continuously in the circumferential direction. The n fuel injection holes include a first injection hole group including one or more of the fuel injection holes, and a second injection hole including one or more of the fuel injection holes other than the fuel injection holes forming the first injection hole group. a group of pores;
The fuel injection amount from each of the fuel injection holes forming the first injection hole group is different from the fuel injection amount from each of the fuel injection holes forming the second injection hole group,
A portion occupied by the first injection hole group is an area having an angle difference θ2 [°] between a pair of fuel injection holes arranged at both ends of the first injection hole group in the circumferential direction of 80° or more. The gas turbine combustor according to any one of claims 1 to 4, wherein The n fuel injection holes are arranged such that an angle difference θ [°] between any pair of the fuel injection holes adjacent in the circumferential direction is 0.8≦n×θ/360≦1.2. The gas turbine combustor according to any one of claims 1 to 5, characterized in that: The gas turbine combustor according to any one of claims 1 to 6, wherein a plurality of said fuel injection holes are formed at equal intervals in the circumferential direction of said gas turbine combustor. The gas turbine combustor according to any one of claims 1 to 7, characterized in that the gas turbine combustor is configured to burn a mixed fuel of air and fuel. A plurality of swirlers provided to protrude outward from the outer peripheral surface of the cylindrical first nozzle ,
The gas turbine combustor according to any one of claims 1 to 8, wherein each of said n fuel injection holes communicates with inner spaces of said plurality of swirlers. a gas turbine combustor according to any one of claims 1 to 9;
a compressor for producing compressed air supplied to the gas turbine combustor;
a turbine driven by combustion gases produced in the gas turbine combustor;
A gas turbine, comprising: A method for suppressing combustion oscillations in a gas turbine combustor comprising one cylindrical first nozzle and a plurality of second nozzles circumferentially arranged to surround the first nozzle, the method comprising:
The cylindrical first nozzle is configured to inject fuel from n (n is an integer equal to or greater than 2) fuel injection holes arranged in the circumferential direction so as to surround the axial center of the first nozzle. is ,
The n fuel injection holes are arranged such that an angle difference θ [°] between any pair of the fuel injection holes adjacent in the circumferential direction is 0<n×θ/360<2,
The first nozzle injects fuel from all of the fuel injection holes such that the amount of fuel injected from one or more of the fuel injection holes is different from the amount of fuel injected from the other one or more of the fuel injection holes. A method for suppressing combustion oscillations in a gas turbine combustor, characterized by:

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