JP2018136056A - Combustor and gas turbine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a combustor and gas turbine, which can inhibit generation of combustion vibration while suppressing an increase in man hours related to manufacture of a main burner.SOLUTION: A combustor includes as a main burner 16, a first burner 16A for generating a mixture by circling primary air, and a second burner 16B for generating a mixture by circling primary air in an opposite direction relative to the first burner 16A. Multiple main burners 16 are arranged while being spaced apart between them in a circumferential direction. The first burner 16A and the second burner 16B are arranged in a non-periodic arrangement pattern across the whole circumference in the circumferential direction.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a combustor and a gas turbine.

A gas turbine combustor may include a plurality of main burners having the same shape and arranged at equal intervals in the circumferential direction.
In Patent Document 1, in order to form a wide range of combustion flames and realize stability and low emission, the shape of the mixing passage with the air in the wake of the fuel supply nozzle is made different so that a flame with a short outer diameter is large. And a technique for forming an elongated flame is described.
In Patent Document 2, in a combustor including a plurality of swirlers having swirl shafts arranged in parallel to the central axis in the circumferential direction, shear generated when outer edges of swirl flows by adjacent swirlers merge is reduced, and NOx In order to reduce CO emission and CO emission, a technique is described in which a swirl flow is given to each swirler so that the swirl directions of adjacent swirlers are opposite to each other.

US Pat. No. 6,931,853 U.S. Pat. No. 9500368

For example, when the flames formed by a plurality of main burners arranged side by side in the circumferential direction all have the same characteristics, the shape of the flame in the circumferential direction is uniform, and the axial length of the flame is also uniform in the circumferential direction. Become.
The main burner described in Patent Document 2 is arranged such that the turning direction is opposite between main burners adjacent in the circumferential direction. However, the flame formed by the main burner described in Patent Document 2 also becomes uniform in the circumferential direction.
When a uniform flame is formed in the circumferential direction in this way, when the pressure fluctuation occurs in the main burner, the flame causes the same fluctuation in the circumferential direction. When the flames of each other fluctuate in phase, the amplitude of fluctuation of the heat generation rate in the combustor increases and combustion vibration increases.
On the other hand, when using a plurality of main burners having different outer shapes in order to change the shape of the flame, as in the combustor described in Patent Document 1, there is a problem that the number of steps involved in manufacturing the main burner increases. .

  The present invention has been made in view of the above circumstances, and provides a combustor and a gas turbine capable of suppressing the occurrence of combustion vibration while suppressing an increase in the number of steps for manufacturing a main burner. It is.

In order to solve the above problems, the following configuration is adopted.
According to the first aspect of the present invention, the combustor generates the air-fuel mixture by swirling the primary air in a direction opposite to the first burner, and rotating the primary air to generate the air-fuel mixture. A second burner as a main burner, and a plurality of the main burners are arranged at intervals in the circumferential direction, and the first burner and the first burner are arranged in a non-periodic arrangement pattern over the entire circumference in the circumferential direction. Two burners are arranged.
By arranging the first burner and the second burner in which the primary air swirl directions are opposite to each other in a non-periodic manner over the entire circumference in the circumferential direction, a uniform flame is produced in the circumferential direction. This can be suppressed. Therefore, it is not necessary to use a plurality of types of main burners having different external shapes.
Therefore, generation | occurrence | production of a combustion vibration can be suppressed, suppressing the man-hour concerning manufacture of a main burner increasing.

According to the second aspect of the present invention, the first burner according to the first aspect and the second burner may be arranged in an asymmetric arrangement pattern in the circumferential direction.
That is, since the first burner and the second burner are not arranged rotationally symmetrically, it is possible to suppress a uniform flame in the circumferential direction.

According to the third aspect of the present invention, in the first burner and the second burner according to the first aspect, the center of gravity position of the overall heat generation rate of the plurality of main burners is offset from the center position in the circumferential direction. It may be arranged in an arrangement pattern.
In this way, by offsetting the position of the center of gravity with the heat generation rate of the flame by each main burner as an index from the center position of the arrangement of the plurality of main burners, the balance of the flame in the circumferential direction is disrupted and a uniform flame can be obtained. Can be suppressed.

According to the fourth aspect of the present invention, the first burner according to the first aspect and the second burner are in the direction of the radial flow generated at the boundary between the first burner and the second burner in the circumferential direction. You may arrange | position with the arrangement | positioning pattern from which the magnitude | size of the synthetic | combination vector which respectively synthesize | combined the corresponding unit vector becomes more than the magnitude | size of the said unit vector.
In this way, the arrangement pattern in the circumferential direction of the first burner and the second burner is an arrangement pattern in which the size of the combined vector is greater than the size of the unit vector, thereby disrupting the balance of the flame in the circumferential direction. It can suppress that it becomes a uniform flame.

According to a fifth aspect of the present invention, in the combustor according to the first aspect, the plurality of main burners arranged at intervals in the circumferential direction are composed of one or a plurality of main burners adjacent to each other in the circumferential direction. And when it divides | segments into the group which consists of the same number of main burners in the circumferential direction, you may make it the arrangement | positioning relationship of the 1st burner and the 2nd burner in at least one said group differ from the said other group.
By comprising in this way, it can suppress that a uniform flame is formed in the circumferential direction.

According to the sixth aspect of the present invention, the gas turbine includes the combustor according to any one of the first to fifth aspects.
By comprising in this way, it can reduce that an operating state becomes unstable by combustion vibration.

  According to the combustor and the gas turbine, it is possible to suppress the occurrence of combustion vibration while suppressing an increase in the number of man-hours for manufacturing the main burner.

It is a figure which shows schematic structure of the gas turbine in 1st embodiment of this invention. It is a figure which shows schematic structure of the combustor in 1st embodiment of this invention. It is a figure which shows arrangement | positioning of the main burner in 1st embodiment of this invention. It is a figure which shows the turning direction of the main burner in 1st embodiment of this invention. It is a figure which shows the gravity center position of the heat rate in 1st embodiment of this invention. It is a figure which shows the synthetic | combination vector in 1st embodiment of this invention. It is a figure equivalent to FIG. 4 in 2nd embodiment of this invention. It is a figure equivalent to FIG. 4 in 3rd embodiment of this invention. It is a figure equivalent to FIG. 4 in 4th embodiment of this invention. It is a graph in which the vertical axis on the left is the distance between the heat generation rate gravity center and the center of the combustor, the vertical axis on the right is the magnitude of the combined vector, and the horizontal axis is the case number.

(First embodiment)
Next, a combustor and a gas turbine in a first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a schematic configuration of a gas turbine in a first embodiment of the present invention.
As shown in FIG. 1, the gas turbine 1 includes a compressor 2, a combustor 3, and a turbine 4.
The compressor 2 compresses the air A to generate compressed air. The combustor 3 burns the fuel F in the compressed air generated by the compressor 2 to generate high-temperature and high-pressure combustion gas. The turbine 4 is driven by the combustion gas generated by the combustor 3 and converts the energy of the combustion gas into rotational energy.

The compressor 2 includes a compressor rotor 6 and a compressor casing 7. The turbine 4 includes a turbine rotor 8 and a turbine casing 9.
The compressor rotor 6 and the turbine rotor 8 are arranged in series and rotate around the rotation axis Ar. The turbine rotor 8 and the compressor rotor 6 are integrally connected, and the compressor rotor 6 and the turbine rotor 8 constitute a gas turbine rotor 10. For example, a rotor of a generator GEN is connected to the gas turbine rotor 10.

  The compressor casing 7 covers the compressor rotor 6 and supports it rotatably. Similarly, the turbine casing 9 covers the turbine rotor 8 and supports it rotatably. The compressor casing 7 and the turbine casing 9 are connected to each other, and the compressor rotor 6 and the turbine rotor 8 constitute a gas turbine rotor 10. The combustor 3 is fixed to the gas turbine casing 11.

FIG. 2 is a diagram showing a schematic configuration of the combustor in the first embodiment of the present invention. FIG. 3 is a view showing the arrangement of the main burners in the first embodiment of the present invention.
As shown in FIG. 2, the combustor 3 includes a combustion cylinder (or tail cylinder) 13 and a fuel ejector 14A. The combustion cylinder 13 burns the fuel F therein, and sends the combustion gas generated as a result of the combustion of the fuel F to the turbine 4. The fuel ejector 14 </ b> A ejects fuel F and compressed air A into the combustion cylinder 13.

As shown in FIG. 3, the fuel ejector 14 </ b> A includes a pilot burner 15, a main burner 16, and a burner holding cylinder 17.
The pilot burner 15 is disposed on the combustor axis Ac, and diffuses and burns fuel. The pilot burner 15 includes a pilot nozzle 18, a pilot burner cylinder 19, and a pilot swirler (not shown).

  The pilot nozzle 18 is formed to extend in the axial direction Da around the combustor axis Ac. The pilot nozzle 18 has, for example, an injection hole 18a for fuel injection at its downstream end.

  The pilot burner tube 19 includes a main body portion 21 and a cone portion 22. The main body 21 covers the outer periphery of the pilot nozzle 18. The cone portion 22 is disposed on the downstream side of the main body portion 21 and is formed so as to gradually increase in diameter toward the downstream side.

  The pilot swirler (not shown) is arranged upstream in the axial direction Da from the position where the injection hole of the pilot nozzle 18 is formed. This pilot swirler (not shown) turns compressed air (primary air) A flowing from the upstream side around the combustor axis Ac as a turning center. The pilot swirler (not shown) extends radially inward from the inner peripheral surface of the main body 21 of the pilot burner cylinder 19. A plurality of these pilot swirlers (not shown) are formed at intervals in the circumferential direction, for example.

  In the pilot burner 15 having the above-described configuration, the compressed air A compressed by the compressor 2 flows into the pilot burner cylinder 19 from the upstream side. Further, fuel is injected from the injection hole of the pilot nozzle 18. This fuel is jetted from the pilot burner cylinder 19 toward the combustion cylinder 13 together with the compressed air A to which a swirl component is given by a pilot swirler (not shown), and diffusely burns in the combustion cylinder 13.

A plurality of main burners 16 are provided and arranged so as to surround the outer periphery of the pilot burner 15 to premix and burn the fuel. These main burners 16 are spaced apart in the circumferential direction around the combustor axis Ac, and more specifically are arranged at equal intervals.
The main burner 16 includes a main nozzle 23, a main burner cylinder 24, and a main swirler 25.
The main nozzle 23 is formed to extend in parallel with the combustor axis line Ac. The main nozzles 23 have, for example, fuel injection holes 23a on the outer peripheral surface thereof.

The main burner cylinder 24 covers the outer periphery of the main nozzle 23. In the main burner cylinder 24 illustrated in FIG. 3, a portion disposed on the inner side in the radial direction centering on the combustor axis line Ac also serves as a part of the pilot burner cylinder 19.
The main swirler 25 turns the compressed air (primary air) A flowing from the upstream side with the main nozzle 23 as the turning center. The main swirler 25 extends from the inner peripheral surface of the main burner cylinder 24 toward the main nozzle 23. A plurality of main swirlers 25 are provided at intervals in the circumferential direction around the main nozzle 23 in the main burner 16 provided in a plurality.

  The burner holding cylinder 17 holds the pilot burner 15 and the main burner 16 described above. More specifically, the pilot burner 15 and the main burner 16 are held so that the plurality of main burners 16 surround the outer periphery of the pilot burner 15.

  In the main burner 16 having the above-described configuration, the compressed air A compressed by the compressor 2 flows into the main burner cylinder 24 from the upstream side. Further, fuel is injected from the injection hole of the main nozzle 23. This fuel is mixed with the compressed air A to which the swirl component is imparted by the main swirler 25, or after being injected into the compressed air A, the swirl component is imparted by the main swirler 25. The premixed gas in which the fuel and the compressed air A are mixed is ejected toward the combustion cylinder 13 and premixed and combusted in the combustion cylinder 13.

FIG. 4 is a view showing the turning direction of the main burner in the first embodiment of the present invention.
As shown in FIG. 4, the main burner 16 includes a first burner 16 </ b> A and a second burner 16 </ b> B whose turning directions by the main swirler 25 are opposite to each other. The first burner 16A and the second burner 16B have the same configuration except that the turning directions are opposite to each other. In FIG. 4, the pilot burner 15 is not shown.

  The first burner 16A in the first embodiment has a turning direction counterclockwise when viewed from the combustion cylinder 13 side, and the second burner 16B has a turning direction clockwise when viewed from the combustion cylinder 13 side. In the fuel ejector 14A in the first embodiment, five first burners 16A are continuously arranged in the circumferential direction, and three second burners 16B are continuously arranged in the circumferential direction. Here, the fuel ejector 14A shown in FIG. 4 shows a case where the eight main burners 16 are provided. However, the number of the main burners 16 may be nine or more or seven or less as long as it is plural. good. In FIG. 4, the positions of the eight main burners 16 in the circumferential direction are indicated by arrangement numbers “1” to “8”, respectively.

In the fuel injector 14A, the first burner 16A and the second burner 16B are arranged in a non-periodic arrangement pattern over the entire circumference in the circumferential direction. Here, the “periodic arrangement pattern” is a pattern in which the first burner 16 </ b> A and the second burner 16 </ b> B are arranged in the same order in the circumferential direction around the combustor axis Ac. It is only to be repeated. As an example of a periodic case, when the first burner 16A and the second burner 16B are alternately arranged in the circumferential direction, only the first burner 16A is arranged, or only the second burner 16B is provided. The case where it arrange | positions can be mentioned.
That is, the arrangement pattern of the main burners 16 in the fuel ejector 14A in the first embodiment is such that the first burner 16A and the second burner 16B are arranged around the combustor axis line Ac in the circumferential direction. The patterns in the order are not repeated with only the same pattern.

  In the fuel injector 14A, the first burner 16A and the second burner 16B are arranged in an asymmetric arrangement pattern in the circumferential direction around the combustor axis Ac. This circumferentially asymmetric arrangement pattern means that the first burner 16A and the second burner 16B are not arranged in a so-called rotationally symmetric order. In the following description of the embodiment, as an example of the aperiodic index of the arrangement pattern of the first burner 16A and the second burner 16B, the heat generation rate centroid and the combined vector are used. May be used only.

  In the fuel ejector 14A, the first burner 16A and the second burner 16B have a combustor axis Ac whose center of gravity g (see FIG. 5) of the overall heat generation rate of the plurality of main burners 16 is the center position in the circumferential direction. Are arranged in an arrangement pattern that is offset from When all are the first burners 16A in the circumferential direction, when all are the second burners 16B in the circumferential direction, and when the first burners 16A and the second burners 16B are alternately arranged in the circumferential direction Since the heat generation rate is balanced all around, the center of gravity position g of the heat generation rate and the combustor axis Ac substantially coincide.

  FIG. 5 is a view showing the barycentric position of the heat generation rate in the first embodiment of the present invention. In FIG. 5, “8-1”, “1-2”, “2-3”, “3-4”, “4-5”, “5-6”, and “6-7” This is the position corresponding to the arrangement number of the main burner 16 shown in FIG. As an example, “8-1” indicates a position between the positions “1” and “8” of the main burner 16.

  As shown in FIG. 5, in the fuel injector 14A of the first embodiment, three second burners 16B are continuously arranged in the circumferential direction, and five first burners 16A are continuously arranged in the circumferential direction. Therefore, the heat generation rate is biased in the circumferential direction and is offset to the outside of the position “8-1”. This bias in the heat generation rate is considered to be due to the swirl direction at the boundary between the first burner 16A and the second burner 16B adjacent in the circumferential direction. Therefore, the gravity center position g of the heat generation rate of the fuel injector 14A is offset from the combustor axis Ac to the position “8-1” side. Here, in FIG. 5, when the first burner 16A is provided on the entire circumference (case 0 described later), the heat generation rate becomes “1” over the entire circumference in the circumferential direction (in FIG. 5, (Indicated by a solid line). In this case, the center-of-gravity position g of the heat generation rate overlaps with the combustor axis Ac. Further, when the swirl toward the radially outer side is strong, the heat generation rate is 1.5, and when the swirl toward the radially inner side is strong, the heat generation rate is 0.5 (indicated by a broken line in FIG. 5).

  Further, in the fuel ejector 14A, the size of the combined vector obtained by synthesizing unit vectors corresponding to the direction of the radial flow generated at the boundary between the first burner 16A and the second burner 16B in the circumferential direction is the size of the unit vector. It is arranged in an arrangement pattern that is more than this.

  For example, when the swirl directions of the adjacent main burners 16 are the same, the swirl flows act so as to cancel each other at the boundary, so that the radial flow is not substantially generated. On the other hand, when the swirl directions of the adjacent main burners 16 are opposite, the swirl flows are directed in the same direction in the radial direction at the boundary. That is, a flow inward or outward in the radial direction around the combustor axis Ac is generated at the boundary between the first burner 16A and the second burner 16B. When the radial flow generated at the boundary is expressed by a unit vector having a size of “1”, a unit vector UA that is directed outward in the radial direction and a unit vector UB that is directed radially inward as illustrated in FIG. 4 are drawn. Can do.

FIG. 6 is a diagram showing the combined vector in the first embodiment of the present invention.
As shown in FIG. 6, in the fuel injector 14 in the first embodiment, when the position of the combustor axis Ac is the (0, 0) coordinate, the unit vector UA is determined from the (0, 0) coordinate. The (0,1) coordinate is reached. The unit vector UB extends from the (−0.71, 0.71) coordinate to the (0, 0) coordinate. The sum of these unit vectors UA and UB (hereinafter referred to as a combined vector SV) is about 1.8. That is, the size of the combined vector SV of the unit vectors UA and UB is 1 or more.

  Further, the fuel ejector 14A according to the first embodiment of the present invention includes a plurality of main burners 16 arranged at intervals in the circumferential direction, and a plurality of main burners 16 adjacent to each other in the circumferential direction. When the main burner 16 is divided into a group in the circumferential direction, the arrangement order (arrangement relationship) in the circumferential direction of the first burner 16A and the second burner 16B in at least one group is different from the other groups. ing.

  As shown in FIG. 4, in the fuel injector 14A of the first embodiment, when two main burners 16 adjacent in the circumferential direction are grouped, four groups can be set in the circumferential direction. In this case, when viewed in one of the circumferential directions (for example, clockwise), the arrangement number of the first group G1 composed of the two second burners 16B of “8” and “7” as the arrangement numbers of the main burner 16 and A second group G2 composed of one second burner 16B of "6" and "5" and one first burner 16A can be set. Furthermore, from the third group G3 including only the first burners 16A having the arrangement numbers “4” and “3” of the main burner 16 and the two first burners 16A having the arrangement numbers “2” and “1”. The fourth group G4 can be set. In the first group G1, the arrangement order of the first burner 16A and the second burner 16B in the circumferential direction is different from any of the second group G2 to the fourth group G4. In addition, the main burner 16 combined as a group mentioned above is not restricted to what was mentioned above. For example, the arrangement number “7” and “6”, “5” and “4”, “3” and “2”, “1” and “1” and “ This is the same even if each group of “8” is configured.

  Since the fuel injector 14A of the first embodiment has eight main burners 16, the number of the plurality of main burners 16 that can be equally divided in the circumferential direction is two or four. Although illustration is omitted, the arrangement order of the first burner 16A and the second burner 16B in each group is different in the case of four as in the case of two.

Therefore, according to the first embodiment described above, the first burner 16A and the second burner 16B are arranged in an aperiodic arrangement pattern over the entire circumference in the circumferential direction centering on the combustor axis Ac. .
Thereby, the flame which is not uniform in the circumferential direction can be formed, without using the multiple types of main burner from which an external shape differs.
As a result, it is possible to suppress the occurrence of combustion vibration while suppressing an increase in the number of man-hours for manufacturing the main burner 16.

  In addition, since the first burner 16A and the second burner 16B are not rotationally symmetrical, it is possible to suppress a uniform flame in the circumferential direction.

  Furthermore, the balance of the flame in the circumferential direction is lost by offsetting the center of gravity position g using the flame heat generation rate of each main burner 16 as an index from the combustor axis Ac that is the center position of the arrangement of the plurality of main burners 16. And can suppress a uniform flame.

  In addition, by arranging the arrangement pattern in the circumferential direction of the first burner 16A and the second burner 16B as an arrangement pattern in which the magnitude of the combined vector SV is greater than or equal to the unit vector UA, the balance of the flame in the circumferential direction is improved. It can suppress that it breaks down and becomes a uniform flame.

  Further, the plurality of main burners 16 arranged at intervals in the circumferential direction are divided in the circumferential direction into a group composed of one or a plurality of main burners 16 adjacent to each other in the circumferential direction and the same number of main burners 16. In this case, the arrangement relationship between the first burner 16A and the second burner 16B in at least one group is made different from that in the other groups. Therefore, it can suppress that a uniform flame is formed in the circumferential direction.

(Second embodiment)
Next, a second embodiment of the present invention will be described with reference to the drawings. In the second embodiment, the arrangement pattern of the main burner is changed from the first embodiment described above. Therefore, the same portions as those in the first embodiment described above are described with the same reference numerals, and redundant descriptions are omitted.

FIG. 7 is a view corresponding to FIG. 4 in the second embodiment of the present invention.
As shown in FIG. 7, the fuel ejector 14B in the second embodiment includes a first burner 16A and a second burner 16B as a plurality of main burners 16, similarly to the fuel ejector 14A of the first embodiment described above. And. The first burner 16A and the second burner 16B have the same configuration except that the turning directions are opposite to each other.

  In the fuel injector 14B according to the second embodiment, six first burners 16A are continuously arranged in the circumferential direction, and two second burners 16B are continuously arranged in the circumferential direction. The fuel injector 14B shown in FIG. 7 shows a case where eight main burners 16 are provided as in FIG. 4, but the number of the main burners 16 is nine or more, or seven or less if there are a plurality. There may be.

In the fuel ejector 14B, the first burner 16A and the second burner 16B are disposed in a non-periodic arrangement pattern over the entire circumference in the circumferential direction, similarly to the fuel ejector 14A.
Further, in the fuel ejector 14B, the first burner 16A and the second burner 16B are arranged in a circumferentially asymmetric arrangement pattern (an arrangement pattern that is not rotationally symmetric) about the combustor axis Ac.

Further, in the fuel injector 14B, the gravity center position g of the heat generation rate is offset from the combustor axis Ac, similarly to the fuel injector 14A of the first embodiment.
Further, the fuel ejector 14B has a size of a combined vector SV obtained by synthesizing unit vectors UA and UB corresponding to the direction of the radial flow generated at the boundary between the first burner 16A and the second burner 16B in the circumferential direction. They are arranged in an arrangement pattern that is greater than or equal to the unit vector UA (or UB).

  Further, in the fuel ejector 14B, when two main burners 16 adjacent in the circumferential direction are made into one group, four groups can be set in the circumferential direction. In this case, when viewed in one of the circumferential directions (for example, clockwise), the first group G1 composed of the two second burners 16B and the second group G2 to the fourth group G4 composed of the two first burners 16A. And can be set. In the first group G1, the arrangement order of the first burner 16A and the second burner 16B in the circumferential direction is different from any of the second group G2 to the fourth group G4. Note that the fuel ejector 14B of the second embodiment also has eight main burners 16 as in the first embodiment. That is, the number of the plurality of main burners 16 that can be equally divided in the circumferential direction is two or four.

Therefore, according to the second embodiment described above, similar to the first embodiment, the first burner 16A and the second burner are arranged in a non-periodic arrangement pattern over the entire circumference in the circumferential direction centering on the combustor axis Ac. A burner 16B is arranged.
Thereby, the flame which is not uniform in the circumferential direction can be formed, without using the multiple types of main burner from which an external shape differs.
As a result, it is possible to suppress the occurrence of combustion vibration while suppressing an increase in the number of man-hours for manufacturing the main burner 16.

  In addition, since the first burner 16A and the second burner 16B are not rotationally symmetrical, it is possible to suppress a uniform flame in the circumferential direction.

  Further, since the center of gravity position g using the heat generation rate of the flame by each main burner 16 as an index is offset from the combustor axis Ac which is the center position of the arrangement of the plurality of main burners 16, the balance of the flame in the circumferential direction is improved. It can suppress that it breaks down and becomes a uniform flame.

  Further, by arranging the arrangement pattern in the circumferential direction of the first burner 16A and the second burner 16B as an arrangement pattern in which the magnitude of the combined vector SV is equal to or larger than the magnitude of the unit vector UA (or UB), the circumferential direction It is possible to suppress the balance of the flame in the case of becoming a uniform flame.

  Further, the plurality of main burners 16 arranged at intervals in the circumferential direction are divided in the circumferential direction into a group composed of one or a plurality of main burners 16 adjacent to each other in the circumferential direction and the same number of main burners 16. In this case, the arrangement relationship between the first burner 16A and the second burner 16B in at least one group is made different from that in the other groups. Therefore, it can suppress that a uniform flame is formed in the circumferential direction.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to the drawings. In the third embodiment, like the second embodiment, the arrangement pattern of the main burners is changed from the first embodiment described above. Therefore, the same portions as those in the first embodiment described above are described with the same reference numerals, and redundant descriptions are omitted.

FIG. 8 is a view corresponding to FIG. 4 in the third embodiment of the present invention.
As shown in FIG. 8, the fuel injector 14C according to the third embodiment includes a first burner 16A and a second burner 16B as a plurality of main burners 16, similarly to the fuel injector 14A according to the first embodiment described above. And. The first burner 16A and the second burner 16B have the same configuration except that the turning directions are opposite to each other.

  In the fuel ejector 14C in the third embodiment, four first burners 16A are continuously arranged in the circumferential direction, and four second burners 16B are continuously arranged in the circumferential direction. The fuel injector 14C shown in FIG. 8 shows a case where eight main burners 16 are provided as in FIG. 4, but the number of the main burners 16 is nine or more and seven or less if there are a plurality. There may be.

Similarly to the fuel ejector 14A, the fuel ejector 14C has the first burner 16A and the second burner 16B disposed in an aperiodic arrangement pattern over the entire circumference in the circumferential direction.
Here, in the third embodiment, at first glance, it seems to be a periodic arrangement pattern. However, the periodic arrangement pattern referred to here is an arrangement pattern in which the first burner 16A and the second burner 16B are adjacent in the circumferential direction, for example, in the order of the first burner 16A and the second burner 16B in the circumferential direction. Alternatively, it means an arrangement pattern that appears twice or more while one arrangement pattern in the order of the second burner 16B and the first burner 16A makes one round in the circumferential direction.

Further, in the fuel ejector 14B, the first burner 16A and the second burner 16B are arranged in a circumferentially asymmetric arrangement pattern (an arrangement pattern that is not rotationally symmetric) about the combustor axis Ac.
Further, in the fuel injector 14B, the gravity center position g of the heat generation rate is offset from the combustor axis Ac, similarly to the fuel injector 14A of the first embodiment.
Further, although not shown in the drawing, the fuel ejector 14B is a composite in which unit vectors UA and UB are combined according to the direction of the radial flow generated at the boundary between the first burner 16A and the second burner 16B in the circumferential direction. The vectors SV are arranged in an arrangement pattern in which the size of the vector SV is greater than or equal to the size of the unit vector UA (or UB). Note that the size of the combined vector SV in the third embodiment is twice as large as the unit vector UA (or UB).

  Further, in the fuel ejector 14B, when two main burners 16 adjacent in the circumferential direction are made into one group, four groups can be set in the circumferential direction. In this case, when viewed in one direction (for example, clockwise) in the circumferential direction, the arrangement position of the main burner 16 is composed of one first burner 16A and one second burner 16B with “1” and “8”. The first group G1, the second group G2 composed of two first burners 16A, the third group G3 composed of one second burner 16B and one first burner 16A, and the two first burners 16A The fourth group G4 can be set. In the first group G1, the arrangement order of the first burner 16A and the second burner 16B in the circumferential direction is different from any of the second group G2 to the fourth group G4. Note that the fuel injector 14C of the third embodiment also has eight main burners 16 as in the first embodiment. That is, the number of the plurality of main burners 16 that can be equally divided in the circumferential direction is two or four.

Therefore, according to the third embodiment described above, similarly to the first embodiment, the first burner 16A and the second burner are arranged in a non-periodic arrangement pattern over the entire circumference in the circumferential direction centering on the combustor axis Ac. A burner 16B is arranged.
Thereby, the flame which is not uniform in the circumferential direction can be formed, without using the multiple types of main burner from which an external shape differs.
As a result, it is possible to suppress the occurrence of combustion vibration while suppressing an increase in the number of man-hours for manufacturing the main burner 16.

  In addition, since the first burner 16A and the second burner 16B are not rotationally symmetrical, it is possible to suppress a uniform flame in the circumferential direction.

  Further, since the center of gravity position g using the heat generation rate of the flame by each main burner 16 as an index is offset from the combustor axis Ac which is the center position of the arrangement of the plurality of main burners 16, the balance of the flame in the circumferential direction is improved. It can suppress that it breaks down and becomes a uniform flame.

  Further, by arranging the arrangement pattern in the circumferential direction of the first burner 16A and the second burner 16B as an arrangement pattern in which the magnitude of the combined vector SV is equal to or larger than the magnitude of the unit vector UA (or UB), the circumferential direction It is possible to suppress the balance of the flame in the case of becoming a uniform flame.

  Further, the plurality of main burners 16 arranged at intervals in the circumferential direction are divided in the circumferential direction into a group composed of one or a plurality of main burners 16 adjacent to each other in the circumferential direction and the same number of main burners 16. In this case, the arrangement relationship between the first burner 16A and the second burner 16B in at least one group is made different from that in the other groups. Therefore, it can suppress that a uniform flame is formed in the circumferential direction.

(Fourth embodiment)
Next, a fourth embodiment of the invention will be described with reference to the drawings. In the fourth embodiment, the arrangement pattern of the main burners is changed with respect to the first embodiment described above. The fourth embodiment is different from the first embodiment in that the size of the combined vector is less than “1”. Therefore, the same portions as those in the first embodiment described above are described with the same reference numerals, and redundant descriptions are omitted.

FIG. 9 is a view corresponding to FIG. 4 in the fourth embodiment of the present invention.
As shown in FIG. 9, the fuel injector 14D in the fourth embodiment includes a first burner 16A and a second burner 16B as a plurality of main burners 16, similarly to the fuel injector 14A of the first embodiment described above. And. The first burner 16A and the second burner 16B have the same configuration except that the turning directions are opposite to each other.

  In the fuel ejector 14D in the fourth embodiment, seven first burners 16A are continuously arranged in the circumferential direction, and one second burner 16B is arranged. That is, only one of the plurality of main burners 16 arranged in the circumferential direction is the second burner 16B, and the other is the first burner 16A. The fuel ejector 14D shown in FIG. 9 shows a case where eight main burners 16 are provided as in FIG. 4, but the number of the main burners 16 is nine or more, or seven or less if there are a plurality. There may be.

Similarly to the fuel ejector 14A, the fuel ejector 14D has the first burner 16A and the second burner 16B disposed in an aperiodic arrangement pattern over the entire circumference in the circumferential direction.
Further, in the fuel ejector 14D, the first burner 16A and the second burner 16B are arranged in an asymmetric arrangement pattern (an arrangement pattern that is not rotationally symmetric) in the circumferential direction around the combustor axis Ac.

  Further, in the fuel injector 14D, similarly to the fuel injector 14A of the first embodiment, the gravity center position g of the heat generation rate is offset from the combustor axis Ac.

  Furthermore, the fuel ejector 14D can set four groups in the circumferential direction when the two main burners 16 adjacent in the circumferential direction are grouped. In this case, when viewed in one of the circumferential directions (for example, clockwise), the first group G1 composed of one second burner 16B and one first burner 16A (arrangement number “8” of the main burner 16 and "7"), and the second group G2 to the fourth group G4 consisting of two first burners 16A (arrangement numbers "6" and "5", "4" and "3", "2" and the main burner 16) “1”) can be set. In the first group G1, the arrangement order of the first burner 16A and the second burner 16B in the circumferential direction is different from any of the second group G2 to the fourth group G4. The fuel ejector 14D of the fourth embodiment also has eight main burners 16 as in the first embodiment. That is, the number of the plurality of main burners 16 that can be equally divided in the circumferential direction is two or four.

Therefore, according to the fourth embodiment described above, as in the first embodiment, the first burner 16A and the second burner are arranged in a non-periodic arrangement pattern over the entire circumference in the circumferential direction around the combustor axis Ac. A burner 16B is arranged.
Thereby, the flame which is not uniform in the circumferential direction can be formed, without using the multiple types of main burner from which an external shape differs.
As a result, it is possible to suppress the occurrence of combustion vibration while suppressing an increase in the number of man-hours for manufacturing the main burner 16.

  In addition, since the first burner 16A and the second burner 16B are not rotationally symmetrical, it is possible to suppress a uniform flame in the circumferential direction.

  Further, since the center of gravity position g using the heat generation rate of the flame by each main burner 16 as an index is offset from the combustor axis Ac which is the center position of the arrangement of the plurality of main burners 16, the balance of the flame in the circumferential direction is improved. It can suppress that it breaks down and becomes a uniform flame.

  Further, the plurality of main burners 16 arranged at intervals in the circumferential direction are divided in the circumferential direction into a group composed of one or a plurality of main burners 16 adjacent to each other in the circumferential direction and the same number of main burners 16. In this case, the arrangement relationship between the first burner 16A and the second burner 16B in at least one group is made different from that in the other groups. Therefore, it can suppress that a uniform flame is formed in the circumferential direction.

Next, an example of a combustor having the fuel ejector of each of the above-described embodiments will be described.
For the arrangement patterns in which the first burner 16A and the second burner 16B are arranged from the case 1 to the case 22 shown in the following table, respectively, the center of heat rate (heat rate center of gravity) and the size of the combined vector are obtained, The magnitude of combustion vibration was determined. In the following table, the numbers “1” to “8” described at the top in each column correspond to the position of the main burner 16 in the circumferential direction of each embodiment described above. The leftmost counter-turn number is the number of second burners in one fuel injector. The “heat rate center of gravity” indicates the distance from the combustor axis Ac to the heat rate center of gravity. When calculating the heat generation rate center of gravity, if the swirl toward the radially outer side is strong, the heat generation rate is 1.5, and if the swirl toward the radially inner side is strong, the heat generation rate is set to 0.5.

(Example)
Here, the arrangement of the main burner 16 in the fuel ejector 14A of the first embodiment described above is the case “6”. Furthermore, the arrangement of the main burner 16 in the fuel ejector 14B of the second embodiment is the case “2”. Further, the arrangement of the main burner 16 in the fuel injector 14C of the third embodiment is the case “13”. Furthermore, the arrangement of the main burner 16 in the fuel ejector 14D of the fourth embodiment is the case “1”.
In this table, “0” is indicated when the first burner 16A is arranged, and “1” is indicated when the second burner 16B is arranged.

(Comparative example)
Case “0”, case “5”, case “20”, and case “22” in the above table are arranged in a periodic arrangement pattern over the entire circumference in the circumferential direction. Is arranged.

(Heating rate center of gravity)
The values of the heat generation rate centroids of case “0”, case “5”, case “20”, and case “22”, which are comparative examples, were all “0.0000”.
On the other hand, in all cases except the comparative example, the value of the heat generation rate centroid is larger than “0.0000”.

(Size of composite vector)
FIG. 10 is a graph in which the left vertical axis is the distance between the heat generation rate gravity center and the combustor center, the right vertical axis is the magnitude of the combined vector, and the horizontal axis is the case number. The solid line indicates the value of the heat generation rate centroid, and the broken line indicates the size of the combined vector. In FIG. 10, the left end of the horizontal axis is the case “0”, and the right end is the case “22”. That is, on the horizontal axis, the case number increases toward the right side. In FIG. 10, a thick solid line extending in the horizontal direction is an example of a reference value for the value of the center of gravity of the heat generation rate and the magnitude of the combined vector.

  As shown in FIG. 10, it can be seen that the magnitude of the combined vector (broken line) has a correlation with the value of the heat generation rate gravity center (solid line). The size of the combined vector and the value of the heat generation rate centroid are particularly high in the cases “2”, “6”, and “13” corresponding to the first, second, and third embodiments described above. ing. In addition, in the case “1” corresponding to the fourth embodiment, although the values are lower than those in the cases “2”, “6”, “13”, the magnitude of the composite vector and the value of the heat generation rate centroid Is sufficiently higher than “0”.

When the value of the pressure fluctuation due to the combustion vibration was verified by simulation calculation, it was confirmed that in each of the cases “1”, “2”, “6”, “13”, the combustion vibration tends to be reduced more than the case “0”. It was.
In these cases “1”, “2”, “6”, and “13”, the arrangement of the first burner 16A and the second burner 16B is non-periodic and not rotationally symmetric, and each of the cases generates heat. The value of the rate centroid and the size of the combined vector are larger than in the case “0”, and in particular, in the cases “2” and “6”, the reduction of the combustion vibration becomes remarkable.
That is, it was confirmed that there is a correlation between the non-periodicity of the arrangement pattern of the first burner 16A and the second burner 16B and the reduction of combustion vibration.

The present invention is not limited to the configuration of each of the embodiments described above, and the design can be changed without departing from the gist thereof.
For example, the arrangement pattern is not limited to those in the first to fourth embodiments. That is, the arrangement pattern is not limited to the case “1”, “2”, “6”, “13”. For cases other than case “0”, case “5”, case “20”, and case “22” (arrangement pattern), cases other than case “1”, “2”, “6”, and “13” It may be an arrangement pattern.

DESCRIPTION OF SYMBOLS 1 Gas turbine 2 Compressor 3 Combustor 4 Combustion gas is turbine 4 Turbine 6 Compressor rotor 7 Compressor casing 8 Turbine rotor 9 Turbine casing 10 Gas turbine rotor 11 Gas turbine casing 13 Combustion cylinder 14A, 14B, 14C, 14D Fuel ejection 15 Pilot burner 16 Main burner 16A First burner 16B Second burner 17 Burner holding cylinder 18 Pilot nozzle 18a Injection hole 19 for fuel injection Pilot burner cylinder 21 Main body part 22 Cone part 23 Main nozzle 23a Injection hole 24 for fuel injection Main burner tube 25 Main swirler A Compressed air (primary air)
Ac Combustor axis Ar Rotation axis Da Axial direction F Fuel g Center of gravity G1 First group G2 Second group G3 Third group G4 Fourth group GEN Generator SV Composite vector UA Unit vector UB Unit vector

Claims (6)

A first burner that swirls the primary air to produce an air-fuel mixture;
A second burner that swirls primary air in the opposite direction to the first burner to generate an air-fuel mixture, as a main burner,
A plurality of the main burners are arranged at intervals in the circumferential direction,
A combustor in which the first burner and the second burner are arranged in an aperiodic arrangement pattern over the entire circumference in the circumferential direction. The first burner and the second burner are:
The combustor according to claim 1, wherein the combustor is arranged in a circumferentially asymmetric arrangement pattern. The first burner and the second burner are:
2. The combustor according to claim 1, wherein the center-of-gravity positions of the overall heat generation rates of the plurality of main burners are arranged in an arrangement pattern that is offset from the center position in the circumferential direction. The first burner and the second burner are:
An arrangement pattern in which the size of a combined vector obtained by synthesizing unit vectors corresponding to the direction of the radial flow generated at the boundary between the first burner and the second burner in the circumferential direction is equal to or greater than the size of the unit vector. The combustor according to claim 1, which is arranged. When the plurality of main burners arranged at intervals in the circumferential direction are composed of one or a plurality of main burners adjacent to each other in the circumferential direction, and divided into a group of the same number of main burners in the circumferential direction,
The combustor according to claim 1, wherein an arrangement relationship of the first burner and the second burner in at least one of the groups is different from that of the other groups.   A gas turbine comprising the combustor according to any one of claims 1 to 5.

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