Combustion chamber and gas turbine

Abstract

This combustion chamber comprises several burner groups arranged circumferentially with respect to a combustion chamber axis. Each burner group has multiple burners capable of injecting fuel along with compressed air. Each burner has an airflow path frame through which air can flow and which can inject air, and a nozzle forming a fuel injection orifice through which fuel can be injected into the airflow path frame. The airflow path frame has an air inlet open at an upstream end and an air-mixture outlet open at a downstream end.The air mixture flow path length, which is the distance in the direction of the combustion chamber axis from the fuel injection opening of the nozzle to the air mixture outlet of the air flow path frame, into which fuel is injected from the fuel injection opening, is different between the burner groups that are adjacent to each other in the circumferential direction.

Description

Technical field

[0001] The present disclosure relates to a combustion chamber and a gas turbine.

[0002] Priority is claimed by the Japanese patent application No. 2023-115975 filed on July 14, 2023, the contents of which are incorporated herein by reference. State of the art

[0003] Gas turbines contain a compressor that compresses air, a combustion chamber that burns fuel in the compressed air to produce combustion gas, and a turbine that is driven by the combustion gas from the combustion chamber. The combustion chamber has a cylinder, which is cylindrical around a combustion chamber axis and in which fuel can be burned on an inner circumferential side, and several burners that can inject the fuel into the cylinder along with the compressed air. Each of the multiple burners has an airflow path frame through which air can flow and into which the air can be injected into the cylinder, and a nozzle that can inject the fuel into the airflow path frame.

[0004] In a gas turbine described in the following PTL 1, combustion oscillation is suppressed by changing the mixture flow path lengths of several burners arranged radially apart. Here, the mixture flow path length is the distance from a fuel injection orifice of a nozzle at a specific burner to a mixture outlet formed at a downstream end of an airflow path frame at the burner. List of citations from patent literature

[0005] [PTL 1] Japanese unexamined patent application publication no. 2014-173840 Summary of the invention: Technical problem

[0006] The present disclosure has the purpose of providing a technique capable of stably burning fuel. Solution to the problem

[0007] A combustion chamber, as one aspect according to the present disclosure for achieving the above task, includesA cylinder, which has a cylindrical shape around a combustion chamber axis and in which a combustion chamber, where fuel can be burned, is formed on an inner circumferential side, and several burner groups. Each of the several burner groups has several burners capable of injecting fuel together with compressed air into the cylinder. Each of the several burners has an airflow path frame capable of directing the airflow and injecting the air into the cylinder, and a nozzle in which a fuel injection orifice is formed through which fuel can be injected into the airflow path frame.The airflow path frame has an air inlet open at one end of the airflow path frame on an upstream side in the combustion chamber axis direction, and a mixture outlet open at one end of the airflow path frame on a downstream side in the combustion chamber axis direction. Several target burner groups, which are multiple burner groups of at least some of the multiple burner groups, are arranged circumferentially with respect to the combustion chamber axis. A mixture flow path length, which is a distance in the combustion chamber axis direction from the fuel injection port of the nozzle to the mixture outlet of the airflow path frame, into which fuel is injected from the fuel injection port, is different between the target burner groups that are adjacent to each other circumferentially.

[0008] If any fluctuation occurs, including a concentration fluctuation of the mixture at the mixture outlet, a heat generation fluctuation due to the combustion of the mixture injected from the burner into the cylinder, a pressure fluctuation in the airflow path, and a velocity fluctuation of the mixture in the airflow path, these fluctuations will occur repeatedly. For example, if a concentration fluctuation occurs, the concentration fluctuation will cause a heat generation fluctuation → a pressure fluctuation → a velocity fluctuation → another concentration fluctuation, repeatedly in this sequence.In a case where the positions of the mixture outlets of all burners are the same relative to each other in the combustion chamber axis direction and the mixture flow path lengths of all burners are the same relative to each other, a cycle of these fluctuations can be locked at a specific frequency and combustion oscillation, which causes damage to the burner or the cylinder, can occur.

[0009] There are several vibration modes during combustion. Among these, a representative example is the internal / external vibration mode, in which an annular node is formed in the cylinder around the combustion chamber axis. In this internal / external vibration mode, the amplitude direction in a region on the inner side of the annular node and the amplitude direction in a region on the outer side of the annular node are opposite to each other.

[0010] In this aspect, the mixture flow path length differs between burner groups that are adjacent to each other circumferentially. Therefore, even if any variation occurs in the mixture concentration at the mixture outlet, the heat generation due to the combustion of the mixture injected from the burner into the cylinder, the pressure variation in the airflow path, and the mixture velocity variation in the airflow path, it is possible to suppress the locking with the combustion oscillation in a specific inner and outer oscillation mode, since the frequency of the cycle of the aforementioned variations differs between the burner groups that are adjacent to each other circumferentially.

[0011] A gas turbine, as one aspect of the present disclosure for achieving the above task, includes The combustion chamber comprises one aspect, a compressor capable of compressing air to produce compressed air, and a turbine that can be driven by combustion gases generated by burning fuel in the combustion chamber. The airflow path frame for each of the multiple burner groups in the combustion chamber is configured to allow the compressed air from the compressor to flow from the air inlet into the airflow path frame. Advantageous effects of the invention

[0012] In the aspect described in the present disclosure, the fuel can be burned stably. Brief description of the drawings Fig. Figure 1 is a schematic view showing a configuration of a gas turbine in an embodiment according to the present disclosure. Fig. Figure 2 is a partial cross-sectional view of the gas turbine around a combustion chamber in the embodiment according to the present disclosure. Fig. 3 is a view when looking along arrow III in Fig. 2. Fig. Figure 4 is a cross-sectional view along line IV in Fig. 3. Fig. Figure 5 is a perspective view of an air hole plate in a first embodiment according to the present disclosure. Fig. Figure 6 is an explanatory diagram to describe an internal and external oscillation mode during combustion oscillation. Fig. Figure 7 is a top view of an air hole plate in a second embodiment according to the present disclosure. Fig. 8 is a view showing a cross-section along line VIIIa in an exterior area and a cross-section along line VIIIb in an interior area. Fig. 7 shows. Fig. Figure 9 is a perspective view of the air hole plate in the second embodiment according to the present disclosure. Fig. Figure 10 is an explanatory diagram to describe a circumferential vibration mode during combustion vibration. Fig. Figure 11 is a top view of an air hole plate in a third embodiment according to the present disclosure. Fig. 12 is a view showing a cross-section along line XIIa in an exterior area and a cross-section along line XIIb in an interior area. Fig. 11 shows. Fig. Figure 13 is a perspective view of the air hole plate in the third embodiment according to the present disclosure. Fig. Figure 14 is a top view of an air hole plate in a first modification example according to the present disclosure. Fig. Figure 15 is a cross-sectional view of an air hole plate along the outer circumference of a circle around a combustion chamber axis in a second modification example according to the present disclosure. Description of embodiments

[0013] An embodiment of a method for operating a gas turbine and gas turbine equipment capable of carrying out the method according to the present disclosure is described in detail below with reference to the drawings. [Design of gas turbine]

[0014] As in Fig. As shown in Figure 1, a gas turbine in the present embodiment includes a compressor 10 that can compress air A to produce compressed air Acom, a combustion chamber 20 that can burn fuel F in the compressed air Acom to produce a combustion gas CG, and a turbine 15 that can be driven by the combustion gas CG.

[0015] The compressor 10 has a compressor rotor 11 rotating about a rotor axis Ar and a compressor housing 12 covering the compressor rotor 11. The turbine 15 has a turbine rotor 16 rotating about the rotor axis Ar and a turbine housing 17 covering the turbine rotor 16. Furthermore, the direction in which the rotor axis Ar extends is referred to as a rotor axis direction Da, one side of the rotor axis direction Da is referred to as an axial upstream side Dau, and the other side is referred to as an axial downstream side Dad.

[0016] The compressor 10 is arranged on the axial upstream side Dau with respect to the turbine 15. The compressor rotor 11 and the turbine rotor 16 are located on the same rotor axis Ar and are connected to each other to form a gas turbine rotor 2. For example, a rotor of a generator GEN is connected to the gas turbine rotor 2.

[0017] The gas turbine 1 further includes an intermediate housing 3, which is arranged between the compressor housing 12 and the turbine housing 17. The compressed air Acom from the compressor 10 flows into the intermediate housing 3. The combustion chamber 20 is attached to the intermediate housing 3.

[0018] A fuel supply system 30 is connected to the combustion chamber 20. The combustion chamber 20 can generate the combustion gas CG by burning the fuel F from the fuel supply system 30 in the compressed air Acom from the compressor 10.

[0019] As in Fig. As shown in Figure 2, the combustion chamber 20 has an outer cylinder 21o, an end cover 21e, an inner cylinder 21i, an air hole plate 23, a combustion cylinder 22 in which a combustion chamber, where fuel can be burned, is formed on an inner circumferential side, and several burner groups 26. The outer cylinder 21o, the inner cylinder 21i, and the combustion cylinder 22 all have a cylindrical shape around a combustion chamber axis Ac. Here, one direction in which the combustion chamber axis Ac extends is referred to as a combustion chamber axis direction Dc, one side in the combustion chamber axis direction Dc is simply referred to as an upstream side Dcu, and the other side in the combustion chamber axis direction Dc is simply referred to as a downstream side Dcd.

[0020] One end of the outer cylinder 21o on the downstream side Dcd is connected to the intermediate housing 3. One end of the outer cylinder 21o on the upstream side Dcu is closed by the end cover 21e. The inner cylinder 21i is arranged at a distance on an inner circumferential side of the outer cylinder 21o. A flow path for the compressed air Acom, which has flowed into the intermediate housing 3, is formed between the inner circumferential side of the outer cylinder 21o and an outer circumferential side of the inner cylinder 21i. The air hole plate 23 is arranged on the inner circumferential side of the inner cylinder 21i. Furthermore, the air hole plate 23 is arranged at a distance in the combustion chamber axis direction Dc with respect to the end cover 21e. A flow path for the compressed air Acom is formed between the end cover 21e and the air hole plate 23.The flow path is connected to a flow path between the inner circumferential side of the outer cylinder 21o and the outer circumferential side of the inner cylinder 21i. The air hole plate 23 is attached to the end cover 21e via a support or the like. The inner cylinder 21i is attached to the air hole plate 23. The air hole plate 23 has a downstream end surface 23ds facing the combustion chamber towards the downstream side Dcd, an upstream end surface 23us facing the upstream side Dcu, and several air holes 23h penetrating from the upstream end surface 23us to the downstream end surface 23ds. The combustion cylinder 22 is attached to the downstream side Dcd of the inner cylinder 21i. As described above, an inner circumferential side of the combustion cylinder 22 forms a combustion chamber in which the fuel is burned.

[0021] Each of the multiple burner groups 26 contains several burners 27 capable of injecting the fuel F together with the compressed air Acom into the combustion cylinder 22. Therefore, in the present embodiment, the combustion chamber 20 is referred to as a multi-cluster combustion chamber. Each of the multiple burners 27 includes an airflow path frame 28 through which air can flow and in which air can be injected into the combustion cylinder 22, and a nozzle 29 in which a fuel injection orifice 29o is formed, through which fuel can be injected into the airflow path frame 28. The airflow path frame 28 has an air inlet 28i, which is open at one end of the airflow path frame 28 on the upstream side Dcu, and a mixture outlet 28o, which is open at one end of the airflow path frame 28 on the downstream side Dcd.

[0022] An inner circumferential surface of the airflow path frame 28 of each of the burners 27 is formed by an inner circumferential surface of any air hole 23h of the multiple air holes 23h of the air hole plate 23 described above. Therefore, each of the airflow path frames 28 is formed as a part of the air hole plate 23.

[0023] The nozzle 29 extends in the combustion chamber axis direction Dc. A fuel injection port 29o is formed at one end of the nozzle 29 on the downstream side Dcd. A section of the nozzle 29 on the downstream side Dcd is inserted into the airflow path frame 28, in other words, into the air hole 23h.

[0024] The fuel supply system 30 has a main fuel line connected to a fuel supply source and several branch lines branching off from the main fuel line. Each of the several branch lines is connected to any one of the several nozzles 29.

[0025] As described above, the compressed air Acom, which has flowed into the intermediate housing 3, flows into the airflow path frame 28 for each of the multiple burners 27 through the flow path between the inner circumferential side of the outer cylinder 21o and the outer circumferential side of the inner cylinder 21i, and the flow path between the end cover 21e and the air hole plate 23. The nozzle 29 for each of the multiple burners 27 injects the fuel into the airflow path frame 28. As a result, a mixture of air and fuel is formed in the airflow path frame 28. This mixture is injected from the airflow path frame 28 into the combustion cylinder 22 for each of the multiple burners 27. The fuel injected into the combustion cylinder 22 is burned there. The combustion gas formed by the combustion flows into the turbine 15.

[0026] Detailed embodiments of the combustion chamber are described below. The combustion chamber configuration described above is a configuration common to the combustion chambers of each of the several embodiments described below. [First embodiment of combustion chamber]

[0027] As in Fig. As shown in Figures 3 to 5, the air hole plate 23 of the combustion chamber in the present embodiment has several circumferentially subdivided areas 25, which are arranged in a circumferential direction Dcc with respect to the combustion chamber axis Ac. Any burner group 26 of the several burner groups 26 is provided for each of the several circumferentially subdivided areas 25. Fig. 3 is a view when looking along arrow III in Fig. 2. Fig. Figure 4 is a cross-sectional view along line IV in Fig. 3. Furthermore, Fig. 5 a perspective view of the air hole plate 23.

[0028] In the present embodiment, the number of circumferentially subdivided regions 25 is six. The circumferential lateral angle Dcc with respect to the combustion chamber axis Ac for each circumferentially subdivided region 25 is the same between the circumferentially subdivided regions 25. Therefore, in the present embodiment, the lateral angle of a circumferentially subdivided region 25 is 60° (= 360° ÷ 6). In the present embodiment, among the circumferentially subdivided regions 25, a first circumferentially subdivided region 25a is a region from 330° to 0° and 0° to 30° with respect to the combustion chamber axis Ac. A second circumferentially subdivided region 25b is a region from 30° to 90° with respect to the combustion chamber axis Ac. A third circumferentially subdivided region 25c is a region from 90° to 150° with respect to the combustion chamber axis Ac.A fourth circumferentially subdivided region 25d is a region from 150° to 210° with respect to the combustion chamber axis Ac. A fifth circumferentially subdivided region 25e is a region from 210° to 270° with respect to the combustion chamber axis Ac. A sixth circumferentially subdivided region 25f is a region from 270° to 330° with respect to the combustion chamber axis Ac.

[0029] In the present embodiment, all of the multiple burner groups 26 are the target burner groups. In the present embodiment, an arbitrary burner group 26 of the multiple burner groups 26 is provided for each of the multiple circumferentially subdivided areas 25. Therefore, the multiple burner groups 26 are arranged in the circumferential direction Dcc. Furthermore, the lateral angle in the circumferential direction Dcc with respect to the combustion chamber axis Ac is the same for each of the multiple burner groups 26.In the following description, a burner group 26 provided in the first circumferentially subdivided area 25a is referred to as a first burner group 26a, a burner group 26 provided in the second circumferentially subdivided area 25b is referred to as a second burner group 26b, a burner group 26 provided in the third circumferentially subdivided area 25c is referred to as a third burner group 26c, a burner group 26 provided in the fourth circumferentially subdivided area 25d is referred to as a fourth burner group 26d, a burner group 26 provided in the fifth circumferentially subdivided area 25e is referred to as a fifth burner group 26e, and a burner group 26 provided in the sixth circumferentially subdivided area 25f is referred to as a sixth burner group 26f.

[0030] Here, as in Fig. Figure 4 shows that a distance in the combustion chamber axis direction Dc from the air inlet 28i of the airflow path frame 28 to the mixture outlet 28o of the airflow path frame 28 is called an airflow path length La. Furthermore, a distance in the combustion chamber axis direction Dc from the fuel injection port 29o of the nozzle 29 to the mixture outlet 28o of the airflow path frame 28, into which the nozzle 29 is inserted, is called a mixture flow path length Lm. Additionally, a distance in the combustion chamber axis direction Dc from the air inlet 28i of the airflow path frame 28 to the fuel injection port 29o of the nozzle 29, which injects the fuel into the airflow path frame 28, is called an insertion length Li. The airflow path length La, the mixture flow path length Lm, and the insertion length Li are related as follows. La=Lm+Li

[0031] The positions of the mixture outlets 28o of all airflow path frames 28 in the combustion chamber axis direction Dc are identical to each other. Therefore, the downstream end surface 23ds of the air hole plate 23, in which the mixture outlet 28o of each of the airflow path frames 28 is formed, is a flat surface.

[0032] The mixture flow path length Lmb of the multiple burners 27 forming the second burner group 26b is shorter than the mixture flow path length Lma of the multiple burners 27 forming the first burner group 26a. The mixture flow path length Lmc of the multiple burners 27 forming the third burner group 26c is shorter than the mixture flow path length Lmb of the multiple burners 27 forming the second burner group 26b. The mixture flow path length Lmd of the multiple burners 27 forming the fourth burner group 26d is the same length as the mixture flow path length Lmb of the multiple burners 27 forming the second burner group 26b. Therefore, the mixture flow path length Lmd of the multiple burners 27 forming the fourth burner group 26d is shorter than the mixture flow path length Lma of the multiple burners 27 forming the first burner group 26a, and longer than the mixture flow path length Lmc of the multiple burners 27 forming the third burner group 26c.The mixture flow path length Lme of the multiple burners 27 forming the fifth burner group 26e is the same length as the mixture flow path length Lmc of the multiple burners 27 forming the third burner group 26c. Therefore, the mixture flow path length Lme of the multiple burners 27 forming the fifth burner group 26e is shorter than the mixture flow path length Lma of the multiple burners 27 forming the first burner group 26a and the mixture flow path length Lmb of the multiple burners 27 forming the second burner group 26b. The mixture flow path length Lmf of the multiple burners 27 forming the sixth burner group 26f is the same length as the mixture flow path length Lmb of the multiple burners 27 forming the second burner group 26b and the mixture flow path length Lmd of the multiple burners 27 forming the fourth burner group 26d.Therefore, the mixture flow path length Lmf of the several burners 27 forming the sixth burner group 26f is shorter than the mixture flow path length Lma of the several burners 27 forming the first burner group 26a, and longer than the mixture flow path length Lmc of the several burners 27 forming the third burner group 26c.

[0033] Therefore, in the present embodiment, the mixture flow path length Lm between the burner groups 26, which are adjacent to each other in the circumferential direction Dcc (or between the circumferentially subdivided areas 25), is different.

[0034] An airflow path length Lab of the multiple burners 27 forming the second burner group 26b is shorter than an airflow path length Laa of the multiple burners 27 forming the first burner group 26a. An airflow path length Lac of the multiple burners 27 forming the third burner group 26c is shorter than the airflow path length Lab of the multiple burners 27 forming the second burner group 26b. An airflow path length Lad of the multiple burners 27 forming the fourth burner group 26d is the same length as the airflow path length Lab of the multiple burners 27 forming the second burner group 26b. Therefore, the airflow path length Lad of the several burners 27 forming the fourth burner group 26d is shorter than the airflow path length Laa of the several burners 27 forming the first burner group 26a, and longer than the airflow path length Lac of the several burners 27 forming the third burner group 26c.The airflow path length Lae of the multiple burners 27 forming the fifth burner group 26e is the same length as the airflow path length Lac of the multiple burners 27 forming the third burner group 26c. Therefore, the airflow path length Lae of the multiple burners 27 forming the fifth burner group 26e is shorter than the airflow path length Laa of the multiple burners 27 forming the first burner group 26a and the airflow path length Lab of the multiple burners 27 forming the second burner group 26b. The airflow path length Laf of the multiple burners 27 forming the sixth burner group 26f is the same length as the airflow path length Lab of the multiple burners 27 forming the second burner group 26b and the airflow path length Lad of the multiple burners 27 forming the fourth burner group 26d.Therefore, the airflow path length Laf of the several burners 27 forming the sixth burner group 26f is shorter than the airflow path length Laa of the several burners 27 forming the first burner group 26a, and longer than the airflow path length Lac of the several burners 27 forming the third burner group 26c.

[0035] Therefore, in the present embodiment, the airflow path length La is different between the burner groups 26 that are adjacent to each other in the circumferential direction Dcc (or between the circumferentially subdivided regions 25). Furthermore, in the present embodiment, the position of the air inlet 28i in the combustion chamber axis direction Dc is different between the burner groups 26 that are adjacent to each other in the circumferential direction Dcc (or between the circumferentially subdivided regions 25). Therefore, as in Fig. 4 and Fig. Figure 5 shows the position of the upstream end surface 23us of the air hole plate 23, in which the air inlets 28i of the air flow path frame 28 of the multiple burners 27 forming the second burner group 26b are formed, shifted to the downstream side Dcd in relation to the upstream end surface 23us of the air hole plate 23, in which the air inlets 28i of the air flow path frame 28 of the multiple burners 27 forming the first burner group 26a are formed. The position of the upstream end surface 23us of the air hole plate 23, in which the air inlets 28i of the air flow path frame 28 of the multiple burners 27 forming the third burner group 26c are formed, is shifted towards the downstream side Dcd with respect to the upstream end surface 23us of the air hole plate 23, in which the air inlets 28i of the air flow path frame 28 of the multiple burners 27 forming the second burner group 26b are formed.The position of the upstream end surface 23us of the air hole plate 23, in which the air inlets 28i of the air flow path frame 28 of the multiple burners 27 forming the fourth burner group 26d are formed, is shifted towards the upstream side Dcu with respect to the upstream end surface 23us of the air hole plate 23, in which the air inlets 28i of the air flow path frame 28 of the multiple burners 27 forming the third burner group 26c are formed. The position of the upstream end surface 23us of the air hole plate 23, in which the air inlets 28i of the air flow path frame 28 of the multiple burners 27 forming the fifth burner group 26e are formed, is shifted towards the downstream side Dcd with respect to the upstream end surface 23us of the air hole plate 23, in which the air inlets 28i of the air flow path frame 28 of the multiple burners 27 forming the fourth burner group 26d are formed.The position of the upstream end surface 23us of the air hole plate 23, in which the air inlets 28i of the air flow path frames 28 of the multiple burners 27 forming the sixth burner group 26f are formed, is shifted to the upstream side Dcu with respect to the upstream end surface 23us of the air hole plate 23, in which the air inlets 28i of the air flow path frames 28 of the multiple burners 27 forming the fifth burner group 26e are formed, and is shifted to the downstream side Dcd with respect to the upstream end surface 23us of the air hole plate 23, in which the air inlets 28i of the air flow path frames 28 of the multiple burners 27 forming the first burner group 26a are formed.Therefore, in the present embodiment, the upstream end surfaces 23us for each of the multiple burner groups 26 have a step in the combustion chamber axis direction Dc between the upstream end surfaces 23us of the burner groups 26 that are adjacent to each other in the circumferential direction Dcc. In other words, in a region where there is a transition in the upstream end surface 23us from one circumferentially subdivided region 25 to the other circumferentially subdivided region 25 of two circumferentially subdivided regions 25 that are adjacent to each other in the circumferential direction Dcc, the position of the upstream end surface 23us in the combustion chamber axis direction Dc changes stepwise.

[0036] The insertion length Li of the multiple burners 27 forming the first burner group 26a, the insertion length Li of the multiple burners 27 forming the second burner group 26b, the insertion length Li of the multiple burners 27 forming the third burner group 26c, the insertion length Li of the multiple burners 27 forming the fourth burner group 26d, the insertion length Li of the multiple burners 27 forming the fifth burner group 26e, and the insertion length Li of the multiple burners 27 forming the sixth burner group 26f are equal to each other.

[0037] It is assumed that the positions of the mixture outlets 28o of all burners 27 are equal to each other in the combustion chamber axis direction Dc and that the mixture flow path lengths Lm of all burners 27 are equal to each other. In this case, if any fluctuation occurs in the concentration of the mixture at the mixture outlet 28o, the heat generation fluctuation due to the combustion of the mixture injected by the burner 27 into the combustion cylinder 22, the pressure fluctuation in the airflow path frame 28 of the burner 27, and the velocity fluctuation of the mixture in the airflow path frame 28, these fluctuations occur repeatedly. For example, if a concentration fluctuation occurs, the concentration fluctuation will cause a heat generation fluctuation → a pressure fluctuation → a velocity fluctuation → another concentration fluctuation, repeatedly in this sequence.Then a cycle of these fluctuations can be locked at a specific frequency and combustion oscillation, which causes damage to the burner 27 or the combustion cylinder 22, can occur.

[0038] There are several vibration modes during combustion. Among these modes, one representative example is the vibration mode shown in... Fig. Figure 6 shows an inner and outer oscillation mode in which an annular node Nc is formed in the combustion cylinder 22 around the combustion chamber axis Ac. In this inner and outer oscillation mode, an amplitude direction in a region on an inner circumferential side of the annular node Nc and an amplitude direction in a region on an outer circumferential side of the annular node Nc are opposite to each other.

[0039] In the present embodiment, as described above, the mixture flow path length Lm between the burner groups 26, which are adjacent to each other in the circumferential direction Dcc (or between the circumferentially subdivided areas 25), is different.Therefore, even if any fluctuation occurs among the concentration fluctuation of the mixture at the mixture outlet 28o, the heat generation fluctuation due to the combustion of the mixture injected from the burner 27 into the combustion cylinder 22, the pressure fluctuation in the airflow path frame 28 of the burner 27 and the velocity fluctuation of the mixture in the airflow path frame 28, it is possible to suppress the locking with the combustion oscillation in a specific inner and outer oscillation mode, since the frequency of the cycle of the fluctuations described above is different between the burner groups 26 that are adjacent to each other in the circumferential direction Dcc (or between the circumferentially subdivided areas 25).

[0040] Furthermore, in the present embodiment, the position of the upstream end surface 23us for each of the multiple burner groups 26 in the combustion chamber axis direction Dc is differentiated between the upstream end surfaces 23us of the burner groups 26 that are adjacent to each other in the circumferential direction Dcc, the insertion lengths Li of the multiple burners 27 for each of the multiple burner groups 26 are made equal to each other, and the area from the air inlets 28i to the fuel injection ports 29o in the airflow path frame 28 for each of the multiple burner groups 26 is made essentially the same. Therefore, it is possible to design the mixture flow path length Lm for each of the multiple burner groups 26 to be relatively small, which is effective in suppressing the occurrence of combustion oscillations. [Second embodiment of combustion chamber]

[0041] As in Fig. As shown in Figure 7, the air hole plate 23 of the combustion chamber in the present embodiment has an inner region 24i, which contains the combustion chamber axis Ac, and an annular outer region 24o, which adjoins the inner region 24i on its outer circumferential side. The outer region 24o has several circumferentially subdivided regions 25, which are arranged in the circumferential direction Dcc with respect to the combustion chamber axis Ac. One burner group 26 of the several burner groups 26 is provided in the inner region 24i. Hereinafter, the burner group 26 provided in the inner region 24i is referred to as an inner burner group 26i. In addition, any one burner group 26 of the several burner groups 26 is provided in each of the several circumferentially subdivided regions 25 of the outer region 24o.In the following, the burner group 26, which is provided for each of the several circumferentially subdivided areas 25 of the outer area 24o, is referred to as an outer burner group 26o.

[0042] In the present embodiment, as in the first embodiment, the number of circumferentially subdivided regions 25 is six. The circumferential lateral angle Dcc with respect to the combustion chamber axis Ac for each circumferentially subdivided region 25 is the same between the circumferentially subdivided regions 25. In the present embodiment, the first circumferentially subdivided region 25a is a region from 330° to 0° and from 0° to 30° with respect to the combustion chamber axis Ac. The second circumferentially subdivided region 25b is a region from 30° to 90° with respect to the combustion chamber axis Ac. The third circumferentially subdivided region 25c is a region from 90° to 150° with respect to the combustion chamber axis Ac.The fourth circumferentially subdivided region 25d is a region from 150° to 210° with respect to the combustion chamber axis Ac. The fifth circumferentially subdivided region 25e is a region from 210° to 270° with respect to the combustion chamber axis Ac. The sixth circumferentially subdivided region 25f is a region from 270° to 330° with respect to the combustion chamber axis Ac.

[0043] In the present embodiment, all of the outer burner groups 26o provided for each of the several circumferentially subdivided areas 25 of the outer area 24o are the target burner groups. In the present embodiment, the outer burner group 26o provided for each of the several circumferentially subdivided areas 25 is also arranged in the circumferential direction Dcc with respect to the combustion chamber axis Ac. Furthermore, the lateral angle in the circumferential direction Dcc with respect to the combustion chamber axis Ac is the same for each of the several outer burner groups 26o. As in the first embodiment, in the present embodiment, an outer burner group 26o provided in the first circumferentially subdivided area 25a is designated as an outer first burner group 26oa, an outer burner group 26o,The burner provided in the second circumferentially subdivided area 25b is designated as an outer second burner group 26ob; an outer burner group 26o provided in the third circumferentially subdivided area 25c is designated as an outer third burner group 26oc; an outer burner group 26o provided in the fourth circumferentially subdivided area 25d is designated as an outer fourth burner group 26od; an outer burner group 26o provided in the fifth circumferentially subdivided area 25e is designated as an outer fifth burner group 26oe; and an outer burner group 26o provided in the sixth circumferentially subdivided area 25f is designated as an outer sixth burner group 26of.

[0044] In the present embodiment, as in Fig. Figure 8 shows that the positions of the mixture outlets 28o of all airflow path frames 28 are the same in the combustion chamber axis direction Dc. Therefore, the downstream end surface 23ds of the air hole plate 23, in which the mixture outlet 28o of each of the airflow path frames 28 is formed, is a flat surface. Fig. Figure 8 is a view showing a cross-section along line VIIIa in the exterior area 24o and a cross-section along line VIIIb in the interior area 24i. Fig. 7 shows.

[0045] The airflow path length La, the mixture flow path length Lm and the insertion length Li for the multiple burners 27 forming the outer first burner group 26oa, for the multiple burners 27 forming the outer second burner group 26ob, for the multiple burners 27 forming the outer third burner group 26oc, for the multiple burners 27 forming the outer fourth burner group 26od, for the multiple burners 27 forming the outer fifth burner group 26oe and for the multiple burners 27 forming the outer sixth burner group 26of are all the same as in the first embodiment.

[0046] This means that the mixture flow path length Lma for the multiple burners 27 forming the outer first burner group 26oa is longer than the mixture flow path length Lm for the multiple burners 27 forming the other outer burner group 26o. The mixture flow path lengths Lmb for the multiple burners 27 forming the outer second burner group 26ob, Lmd for the multiple burners 27 forming the outer fourth burner group 26od, and Lmf for the multiple burners 27 forming the outer sixth burner group 26of are equal to each other and are shorter than the mixture flow path length Lma for the multiple burners 27 forming the outer first burner group 26oa.The mixture flow path length Lmc for the multiple burners 27 forming the outer third burner group 26oc and the mixture flow path length Lme for the multiple burners 27 forming the outer fifth burner group 26oe are equal to each other and shorter than the mixture flow path length Lmb for the multiple burners 27 forming the outer second burner group 26ob, the mixture flow path length Lmd for the multiple burners 27 forming the outer fourth burner group 26od, and the mixture flow path length Lmf for the multiple burners 27 forming the outer sixth burner group 26of. Therefore, in the present embodiment, the mixture flow path length Lm is also different between the outer burner groups 26o that are adjacent to each other in the circumferential direction Dcc (or between the circumferentially subdivided regions 25).

[0047] Furthermore, the airflow path length Laa for the multiple burners 27 forming the outer first burner group 26oa is longer than the airflow path length La for the multiple burners 27 forming the other outer burner group 26o. The airflow path length Lab for the multiple burners 27 forming the outer second burner group 26ob, the airflow path length Lad for the multiple burners 27 forming the outer fourth burner group 26od, and the airflow path length Laf for the multiple burners 27 forming the outer sixth burner group 26of are equal to each other and are shorter than the airflow path length Laa for the multiple burners 27 forming the outer first burner group 26oa.The airflow path length Lac at the multiple burners 27 forming the outer third burner group 26oc, and the airflow path length Lae at the multiple burners 27 forming the outer fifth burner group 26oe, are equal to each other and are shorter than the airflow path length Lab at the multiple burners 27 forming the outer second burner group 26ob, the airflow path length Lad at the multiple burners 27 forming the outer fourth burner group 26od, and the airflow path length Laf at the multiple burners 27 forming the outer sixth burner group 26of.

[0048] Therefore, in the present embodiment, the airflow path length La between the outer burner groups 26o, which are adjacent to each other in the circumferential direction Dcc (or between the circumferentially subdivided regions 25), is also different. Furthermore, in the present embodiment, the position of the air inlet 28i in the combustion chamber axis direction Dc is also different between the outer burner groups 26o, which are adjacent to each other in the circumferential direction Dcc (or between the circumferentially subdivided regions 25). Therefore, as in Fig. As shown in Figure 9, in the present embodiment, the upstream end surface 23us for each of the several outer burner groups 26o has a step in the combustion chamber axis direction Dc between the upstream end surfaces 23us of the outer burner groups 26o that are adjacent to each other in the circumferential direction Dcc. In other words, in a region where the upstream end surface 23us transitions from one circumferentially subdivided area 25 to the other circumferentially subdivided area 25 of two circumferentially subdivided areas 25 that are adjacent to each other in the circumferential direction Dcc, the position of the upstream end surface 23us changes stepwise in the combustion chamber axis direction Dc.

[0049] The insertion length Li of the multiple burners 27 forming the outer first burner group 26oa, the insertion length Li of the multiple burners 27 forming the outer second burner group 26ob, the insertion length Li of the multiple burners 27 forming the outer third burner group 26oc, the insertion length Li of the multiple burners 27 forming the outer fourth burner group 26od, the insertion length Li of the multiple burners 27 forming the outer fifth burner group 26oe, and the insertion length Li of the multiple burners 27 forming the outer sixth burner group 26of are equal to each other.

[0050] The airflow path lengths Lai of the multiple burners 27 forming the inner burner group 26i are equal to each other and are shorter than the airflow path lengths La of the multiple burners 27 forming each of the multiple outer burner groups 26o. The mixture flow path lengths Lmi of the multiple burners 27 forming the inner burner group 26i are equal to each other and are shorter than the mixture flow path lengths Lm of the multiple burners 27 forming each of the multiple outer burner groups 26o. The inlet lengths Lii of the multiple burners 27 forming the inner burner group 26i are equal to each other.

[0051] In the present embodiment, as described above, the mixture flow path length Lm between the outer burner groups 26o, which are adjacent to each other in the circumferential direction Dcc (or between the circumferentially subdivided areas 25), is also different. Therefore, in the present embodiment, it is also possible to suppress the occurrence of combustion oscillation in the internal and external oscillation mode described above, which leads to damage to the burner 27 or the combustion cylinder 22.

[0052] Among the several vibration modes of combustion vibration, one representative vibration mode, in addition to the internal and external vibration modes described above, is, for example, as in Fig. Figure 10 shows a circumferential vibration mode in which several nodes No., extending radially with respect to the combustion chamber axis Ac, are formed within the combustion cylinder 22. In this circumferential vibration mode, the combustion cylinder 22 is subdivided into several regions in the circumferential direction Dcc by the multiple nodes No., and the amplitude directions in two regions adjacent to each other in the circumferential direction Dcc are opposite to each other. In the present embodiment, as described above, since the mixture flow path length Lm is different between the outer region 24o and the inner region 24i, the occurrence of combustion vibration in the circumferential vibration mode can be suppressed.In the combustion chamber 20 of the first embodiment described above, the occurrence of combustion vibration in the circumferential vibration mode can also be suppressed in a case where the position of the boundary line between the several burner groups 26, which are arranged in the circumferential direction Dcc, deviates from the position of the node formed in the circumferential vibration mode.

[0053] In the present embodiment, the airflow path length Lai for the multiple burners 27 forming the inner burner group 26i is shorter than the airflow path length La for the multiple burners 27 forming each of the multiple outer burner groups 26o. However, the airflow path length Lai for the multiple burners 27 forming the inner burner group 26i can be longer than the airflow path length La for the multiple burners 27 forming each of the multiple outer burner groups 26o. That is, the airflow path length Lai for the multiple burners 27 forming the inner burner group 26i can differ from the airflow path length La for the multiple burners 27 forming each of the multiple outer burner groups 26o.

[0054] In the present embodiment, of the outer area 24o and the inner area 24i, only the outer area 24o has several circumferentially subdivided regions 25 arranged in the circumferential direction Dcc. However, of the outer area 24o and the inner area 24i, only the inner area 24i can have several circumferentially subdivided regions 25 arranged in the circumferential direction Dcc. [Third embodiment of combustion chamber]

[0055] As in Fig. As shown in Figure 11, the air hole plate 23 of the combustion chamber in the present embodiment has an inner region 24i, which contains the combustion chamber axis Ac, and an annular outer region 24o, which adjoins the inner region 24i on the outer circumferential side. The inner region 24i has several inner circumferentially subdivided regions 25i, which are arranged in the circumferential direction Dcc with respect to the combustion chamber axis Ac. The outer region 24o has several outer circumferentially subdivided regions 25o, which are arranged in the circumferential direction Dcc with respect to the combustion chamber axis Ac. Any one burner group 26 of the several burner groups 26 is provided in each of the several inner circumferentially subdivided regions 25i of the inner region 24i. Hereinafter, the burner group 26 that is provided for each of the several inner circumferentially subdivided regions 25i is referred to as the inner burner group 26i.Any one burner group 26 of the several burner groups 26 is provided in each of the several outer circumferentially subdivided areas 25o of the outer area 24o. Hereinafter, the burner group 26 provided for each of the several outer circumferentially subdivided areas 25o is referred to as the outer burner group 26o.

[0056] In the present embodiment, as in the second embodiment, the number of multiple outer circumferentially subdivided regions 25o is six. The circumferential lateral angle Dcc with respect to the combustion chamber axis Ac for each of the multiple outer circumferentially subdivided regions 25o is the same between the multiple outer circumferentially subdivided regions 25o. In the present embodiment, among the multiple outer circumferentially subdivided regions 25o, an outer first circumferentially subdivided region 25oa is a region from 33° to 0° and 0° to 30° with respect to the combustion chamber axis Ac. An outer second circumferentially subdivided region 25ob is a region from 30° to 90° with respect to the combustion chamber axis Ac. An outer third circumferentially subdivided region 25oc is a region from 90° to 150° with respect to the combustion chamber axis Ac.An outer fourth circumferentially subdivided region 25od is a region from 150° to 210° with respect to the combustion chamber axis Ac. An outer fifth circumferentially subdivided region 25oe is a region from 210° to 270° with respect to the combustion chamber axis Ac. An outer sixth circumferentially subdivided region 25of is a region from 270° to 330° with respect to the combustion chamber axis Ac. In the present embodiment, an outer boundary line 24oB, which is a boundary line between the outer circumferentially subdivided regions 25o that are adjacent to each other in the circumferential direction Dcc, is present at the position of 30°, the position of 90°, the position of 150°, the position of 210°, the position of 270°, and the position of 330° with respect to the combustion chamber axis Ac. Each of the outer boundary lines 24oB extends in the radial direction with respect to the combustion chamber axis Ac within the outer area 24o.

[0057] In the present embodiment, all of the outer burner groups 26o provided for each of the several outer circumferentially subdivided regions 25o are the target burner groups. The outer burner group 26o provided for each of the several outer circumferentially subdivided regions 25o is arranged in the circumferential direction Dcc with respect to the combustion chamber axis Ac. Furthermore, the lateral angle in the circumferential direction Dcc with respect to the combustion chamber axis Ac is the same between the several outer burner groups 26o for each of the several outer burner groups 26o. Also in the present embodiment, as in the second embodiment, the outer burner group 26o provided in the outer first circumferentially subdivided region 25oa is designated as the outer first burner group 26oa, and the outer burner group 26o provided in the outer second circumferentially subdivided region 25ob,is designated as the outer second burner group 26ob, the outer burner group 26o, which is provided in the outer third circumferentially subdivided area 25oc, is designated as the outer third burner group 26oc, the outer burner group 26o, which is provided in the outer fourth circumferentially subdivided area 25od, is designated as the outer fourth burner group 26od, the outer burner group 26o, which is provided in the outer fifth circumferentially subdivided area 25oe, is designated as the outer fifth burner group 26oe, and the outer burner group 26o, which is provided in the outer sixth circumferentially subdivided area 25of, is designated as the outer sixth burner group 26of.

[0058] Furthermore, in the present embodiment, the number of multiple inner circumferentially subdivided regions 25i is six. The circumferential lateral angle Dcc with respect to the combustion chamber axis Ac for each of the multiple inner circumferentially subdivided regions 25i is the same between the multiple inner circumferentially subdivided regions 25i. In the present embodiment, among the multiple inner circumferentially subdivided regions 25i, an inner first circumferentially subdivided region 25ia is a region from 0° to 60° with respect to the combustion chamber axis Ac. An inner second circumferentially subdivided region 25ib is a region from 60° to 120° with respect to the combustion chamber axis Ac. An inner third circumferentially subdivided region 25ic is a region from 120° to 180° with respect to the combustion chamber axis Ac.An inner fourth circumferentially subdivided region 25id is a region from 180° to 240° with respect to the combustion chamber axis Ac. An inner fifth circumferentially subdivided region 25ie is a region from 240° to 300° with respect to the combustion chamber axis Ac. An inner sixth circumferentially subdivided region 25if is a region from 300° to 360° with respect to the combustion chamber axis Ac. In the present embodiment, an inner boundary line 24iB, which is a boundary line between the inner circumferentially subdivided regions 25i that are adjacent to each other in the circumferential direction Dcc, is present at the position of 0°, the position of 60°, the position of 120°, the position of 180°, the position of 240° and the position of 300° with respect to the combustion chamber axis Ac. Each of the inner boundary lines 24iB extends in the radial direction with respect to the combustion chamber axis Ac within the inner area 24i.

[0059] In the present embodiment, the position of each inner boundary line 24iB in the circumferential direction Dcc differs from the position of each outer boundary line 24oB in the circumferential direction Dcc.

[0060] In the present embodiment, all of the inner burner groups 26i provided for each of the several inner circumferentially subdivided areas 25i are the target burner groups. The inner burner group 26i provided for each of the several inner circumferentially subdivided areas 25i is arranged in the circumferential direction Dcc with respect to the combustion chamber axis Ac. Furthermore, the lateral angle in the circumferential direction Dcc with respect to the combustion chamber axis Ac is the same between the several inner burner groups 26i for each of the several inner burner groups 26i. In the present embodiment, an inner burner group 26i provided in the inner first circumferentially subdivided area 25ia is designated as an inner first burner group 26ia, and an inner burner group 26i provided in the inner second circumferentially subdivided area 25ib is designated as an inner second burner group 26i.is designated as an inner second burner group 26ib, an inner burner group 26i provided in the inner third circumferentially subdivided area 25ic is designated as an inner third burner group 26ic, an inner burner group 26i provided in the inner fourth circumferentially subdivided area 25id is designated as an inner fourth burner group 26id, an inner burner group 26i provided in the inner fifth circumferentially subdivided area 25ie is designated as an inner fifth burner group 26ie, and an inner burner group 26i provided in the inner sixth circumferentially subdivided area 25if is designated as an inner sixth burner group 26if.

[0061] As in Fig. As shown in Figure 12, in the present embodiment the positions of the mixture outlets 28o of all airflow path frames 28 are the same in the combustion chamber axis direction Dc. Therefore, the downstream end surface 23ds of the air hole plate 23, in which the mixture outlet 28o of each of the airflow path frames 28 is formed, is a flat surface. Fig. 12 is a view showing a cross-section along line XIIa in the exterior area 24o and a cross-section along line XIIb in the interior area 24i. Fig. 11 shows.

[0062] The airflow path length La, the mixture flow path length Lm and the insertion length Li for the multiple burners 27 forming the outer first burner group 26oa, for the multiple burners 27 forming the outer second burner group 26ob, for the multiple burners 27 forming the outer third burner group 26oc, for the multiple burners 27 forming the outer fourth burner group 26od, for the multiple burners 27 forming the outer fifth burner group 26oe and for the multiple burners 27 forming the outer sixth burner group 26of are all the same as in the second embodiment.

[0063] This means that the mixture flow path length Lma for the multiple burners 27 forming the outer first burner group 26oa is longer than the mixture flow path length Lm for the multiple burners 27 forming the other outer burner group 26o. The mixture flow path lengths Lmb for the multiple burners 27 forming the outer second burner group 26ob, Lmd for the multiple burners 27 forming the outer fourth burner group 26od, and Lmf for the multiple burners 27 forming the outer sixth burner group 26of are equal to each other and are shorter than the mixture flow path length Lma for the multiple burners 27 forming the outer first burner group 26oa.The mixture flow path length Lmc for the multiple burners 27 forming the outer third burner group 26oc and the mixture flow path length Lme for the multiple burners 27 forming the outer fifth burner group 26oe are equal to each other and shorter than the mixture flow path length Lmb for the multiple burners 27 forming the outer second burner group 26ob, the mixture flow path length Lmd for the multiple burners 27 forming the outer fourth burner group 26od, and the mixture flow path length Lmf for the multiple burners 27 forming the outer sixth burner group 26of. Therefore, in the present embodiment, the mixture flow path length Lm is also different between the outer burner groups 26o that are adjacent to each other in the circumferential direction Dcc (or between the circumferentially subdivided regions 25).

[0064] Furthermore, the airflow path length Laa for the multiple burners 27 forming the outer first burner group 26oa is longer than the airflow path length La for the multiple burners 27 forming the other outer burner group 26o. The airflow path length Lab for the multiple burners 27 forming the outer second burner group 26ob, the airflow path length Lad for the multiple burners 27 forming the outer fourth burner group 26od, and the airflow path length Laf for the multiple burners 27 forming the outer sixth burner group 26of are equal to each other and are shorter than the airflow path length Laa for the multiple burners 27 forming the outer first burner group 26oa.The airflow path length Lac at the multiple burners 27 forming the outer third burner group 26oc, and the airflow path length Lae at the multiple burners 27 forming the outer fifth burner group 26oe, are equal to each other and are shorter than the airflow path length Lab at the multiple burners 27 forming the outer second burner group 26ob, the airflow path length Lad at the multiple burners 27 forming the outer fourth burner group 26od, and the airflow path length Laf at the multiple burners 27 forming the outer sixth burner group 26of.

[0065] Therefore, in the present embodiment, the airflow path length La between the outer burner groups 26o, which are adjacent to each other in the circumferential direction Dcc (or between the outer circumferentially subdivided areas 25o), is also different. Furthermore, in the present embodiment, the position of the air inlet 28i in the combustion chamber axis direction Dc is also different between the outer burner groups 26o, which are adjacent to each other in the circumferential direction Dcc (or between the outer circumferentially subdivided areas 25o). Therefore, as in Fig. As shown in Figure 13, in the present embodiment, the upstream end surface 23us for each of the several outer burner groups 26o has a step in the combustion chamber axis direction Dc between the upstream end surfaces 23us of the outer burner groups 26o that are adjacent to each other in the circumferential direction Dcc. In other words, in a region where the transition occurs in the upstream end surface 23us from one outer circumferentially subdivided region 25o to the other outer circumferentially subdivided region 25o of two outer circumferentially subdivided regions 25o that are adjacent to each other in the circumferential direction Dcc, the position of the upstream end surface 23us changes stepwise in the combustion chamber axis direction Dc.

[0066] The insertion length Li of the multiple burners 27 forming the outer first burner group 26oa, the insertion length Li of the multiple burners 27 forming the outer second burner group 26ob, the insertion length Li of the multiple burners 27 forming the outer third burner group 26oc, the insertion length Li of the multiple burners 27 forming the outer fourth burner group 26od, the insertion length Li of the multiple burners 27 forming the outer fifth burner group 26oe, and the insertion length Li of the multiple burners 27 forming the outer sixth burner group 26of are equal to each other.

[0067] The airflow path length Laa for the multiple burners 27 forming the inner first burner group 26ia is longer than the airflow path length La for the multiple burners 27 forming the other inner burner group 26i. The airflow path length Lab for the multiple burners 27 forming the inner second burner group 26ib, the airflow path length Lad for the multiple burners 27 forming the inner fourth burner group 26id, and the airflow path length Laf for the multiple burners 27 forming the inner sixth burner group 26if are equal to each other and are shorter than the airflow path length Laa for the multiple burners 27 forming the inner first burner group 26ia.The airflow path length Lac at the multiple burners 27 forming the inner third burner group 26ic, and the airflow path length Lae at the multiple burners 27 forming the inner fifth burner group 26ie, are equal to each other and are shorter than the airflow path length Lab at the multiple burners 27 forming the inner second burner group 26ib, the airflow path length Lad at the multiple burners 27 forming the inner fourth burner group 26id, and the airflow path length Laf at the multiple burners 27 forming the inner sixth burner group 26if.

[0068] Therefore, in the present embodiment, the airflow path length La differs between the inner burner groups 26i that are adjacent to each other in the circumferential direction Dcc (or between the inner circumferentially subdivided regions 25i). Furthermore, in the present embodiment, the position of the air inlet 28i in the combustion chamber axis direction Dc differs between the inner burner groups 26i that are adjacent to each other in the circumferential direction Dcc (or between the inner circumferentially subdivided regions 25i). Therefore, as shown in Fig. As shown in Figure 13, in the present embodiment, the upstream end surface 23us for each of the several inner burner groups 26i has a step in the combustion chamber axis direction Dc between the upstream end surfaces 23us of the inner burner groups 26i that are adjacent to each other in the circumferential direction Dcc. In other words, in a region where the transition occurs in the upstream end surface 23us from one inner circumferentially subdivided region 25i to the other inner circumferentially subdivided region 25i of two inner circumferentially subdivided regions 25i that are adjacent to each other in the circumferential direction Dcc, the position of the upstream end surface 23us changes stepwise in the combustion chamber axis direction Dc.

[0069] The insertion length Li of the multiple burners 27 forming the inner first burner group 26ia, the insertion length Li of the multiple burners 27 forming the inner second burner group 26ib, the insertion length Li of the multiple burners 27 forming the inner third burner group 26ic, the insertion length Li of the multiple burners 27 forming the inner fourth burner group 26id, the insertion length Li of the multiple burners 27 forming the inner fifth burner group 26ie, and the insertion length Li of the multiple burners 27 forming the inner sixth burner group 26if are equal to each other.

[0070] In the present embodiment, as described above, the mixture flow path length Lm is also different between the outer burner groups 26o, which are adjacent to each other in the circumferential direction Dcc (or between the outer circumferentially subdivided areas 25o). Furthermore, in the present embodiment, the mixture flow path length Lm is different between the inner burner groups 26i, which are adjacent to each other in the circumferential direction Dcc (or between the inner circumferentially subdivided areas 25i). Therefore, in the present embodiment, it is possible to suppress the occurrence of combustion oscillation in the inner and outer oscillation modes described above, which lead to damage to the burner 27 or the combustion cylinder 22, in both the outer area 24o and the inner area 24i.

[0071] Furthermore, in the present embodiment, as described above, the position of each inner boundary line 24iB in the circumferential direction Dcc differs from the position of each outer boundary line 24oB in the circumferential direction Dcc. In other words, in the present embodiment, the position of each of the several inner circumferentially subdivided regions 25i in the circumferential direction Dcc differs from the position of each of the several outer circumferentially subdivided regions 25o in the circumferential direction Dcc. Therefore, since the mixture flow path lengths Lm between the outer region 24o and the inner region 24i do not completely coincide, it is possible to suppress the occurrence of combustion oscillation in the circumferential oscillation mode. [First modification example of combustion chamber]

[0072] The number of multiple circumferentially subdivided areas 25 in the first embodiment is six. However, as shown in Fig. As shown in 14, for example, the number of multiple circumferentially subdivided areas can be three, and as long as the number is three or more, the number can be, for example, five, seven, or eight. In the Fig. In the example shown in Figure 14, among the several circumferentially subdivided regions 25, the first circumferentially subdivided region 25a is a region from 330° to 0° and 0° to 90° with respect to the combustion chamber axis Ac. The second circumferentially subdivided region 25b is a region from 90° to 210° with respect to the combustion chamber axis Ac. The third circumferentially subdivided region 25c is a region from 210° to 330° with respect to the combustion chamber axis Ac. Any burner group 26 of the several burner groups 26 is provided in each of the several circumferentially subdivided regions 25. Although Fig. 14. In the first embodiment, where a modification example of the combustion chamber is shown, the number of multiple circumferentially subdivided regions in the combustion chamber of the second or third embodiment can also be three or more, as in the present modification example. Furthermore, in the combustion chamber of the third embodiment, the number of multiple outer circumferentially subdivided regions 25o and the number of multiple inner circumferentially subdivided regions 25i are the same, but the numbers can differ from each other. For example, the number of multiple outer circumferentially subdivided regions 25o can be six, and the number of multiple inner circumferentially subdivided regions 25i can be three. [Second modification example of combustion chamber]

[0073] The upstream end surfaces 23us for each of the multiple burner groups 26 in the first embodiment have a step in the combustion chamber axis direction Dc between the upstream end surfaces 23us of the burner groups 26 that are adjacent to each other in the circumferential direction Dcc. However, as shown in Fig. As shown in Figure 15, all of the upstream end faces 23us for each of the multiple burner groups 26 are located on a virtual plane. In this case, the positions of the air inlets 28i of all burners 27 are equal to each other in the combustion chamber axis direction Dc, and the airflow path lengths La of all burners 27 are equal to each other. On the other hand, in this case, the inlet lengths Li for each of the burner groups 26 that are adjacent to each other in the circumferential direction Dcc are different from each other. Although Fig.15 a modification example of the combustion chamber in the first embodiment, in the combustion chamber in the second embodiment or the third embodiment all of the upstream end surfaces 23us for each of the several burner groups 26 can also be located on a virtual plane as in the present modification example.

[0074] Furthermore, the present disclosure is not limited to the embodiments and modification examples described above. Various additions, modifications, substitutions, partial deletions, and the like can be made without deviating from the conceptual idea and core of the present invention, which are derived from the content defined in the claims and their equivalents. [Additional notes]

[0075] For example, in the embodiments and modification examples described above, the combustion chamber is understood as follows. (1) A combustion chamber according to a first aspect comprises: A cylinder 22, which has a cylindrical shape around a combustion chamber axis Ac and in which a combustion chamber, in which fuel can be burned, is formed on an inner circumferential side, and several burner groups 26. Each of the several burner groups 26 has several burners 27 that are capable of injecting fuel together with compressed air into the cylinder 22. Each of the several burners 27 has an airflow path frame 28 that is capable of directing the airflow and injecting the air into the cylinder 22, and a nozzle 29 in which a fuel injection orifice 29o is formed, through which fuel can be injected into the airflow path frame 28.The airflow path frame 28 has an air inlet 28i, which is open at one end of the airflow path frame 28 on an upstream side Dcu in a combustion chamber axis direction Dc in which the combustion chamber axis Ac extends, and a mixture outlet 28o, which is open at one end of the airflow path frame 28 on a downstream side Dcd in the combustion chamber axis direction Dc. Several target burner groups 26, which are multiple burner groups 26 of at least some of the multiple burner groups 26, are arranged in a circumferential direction Dcc with respect to the combustion chamber axis Ac. A mixture flow path length Lm, which is a distance in the combustion chamber axis direction from the fuel injection opening 29o of the nozzle 29 to the mixture outlet 28o of the air flow path frame 28, into which fuel is injected from the fuel injection opening 29o, is different between the target burner groups 26, which are adjacent to each other in the circumferential direction Dcc.

[0076] If any fluctuation occurs in the concentration of the mixture at the mixture outlet 28o, the heat generation fluctuation due to the combustion of the mixture injected by the burner 27 into the combustion cylinder 22, the pressure fluctuation in the airflow path frame 28, and the velocity fluctuation of the mixture in the airflow path frame 28, these fluctuations occur repeatedly. For example, if a concentration fluctuation occurs, the concentration fluctuation will cause a heat generation fluctuation → a pressure fluctuation → a velocity fluctuation → another concentration fluctuation, repeatedly in this sequence.Then, in a case where the positions of the mixture outlets 28o of all burners 27 are the same in the combustion chamber axis direction Dc and the mixture flow path lengths Lm of all burners 27 are the same, a cycle of these fluctuations at a specific frequency can be locked, and combustion oscillation, which causes damage to the burner 27 or the cylinder 22, can occur.

[0077] There are several vibration modes during combustion. Among these, a representative example is an internal and external vibration mode, in which an annular node Nc is formed in cylinder 22 around the combustion chamber axis Ac. In this internal and external vibration mode, the amplitude direction in the region on the inner circumferential side of the annular node Nc and the amplitude direction in the region on the outer circumferential side of the annular node Nc are opposite to each other.

[0078] In the present aspect, the mixture flow path length Lm differs between the burner groups 26 that are adjacent to each other in the circumferential direction Dcc. Therefore, even if any fluctuation occurs among the concentration fluctuation of the mixture at the mixture outlet 28o, the heat generation fluctuation due to the combustion of the mixture injected from the burner 27 into the cylinder 22, the pressure fluctuation in the airflow path frame 28, and the velocity fluctuation of the mixture in the airflow path frame 28, it is possible to suppress the locking with the combustion oscillation in a specific inner and outer oscillation mode, since the frequency of the cycle of the fluctuations described above differs between the burner groups 26 that are adjacent to each other in the circumferential direction Dcc.

[0079] (2) The combustion chamber according to a second aspect is the combustion chamber 20 according to the first aspect, in which the number of multiple target burner groups 26 is three or more.

[0080] (3) The combustion chamber according to a third aspect is the combustion chamber 20 according to the first aspect or the second aspect, wherein a lateral angle in the circumferential direction Dcc with respect to the combustion chamber axis Ac is the same between the multiple target burner groups 26 for each of the multiple target burner groups 26.

[0081] (4) The combustion chamber according to a fourth aspect is the combustion chamber 20 according to an aspect of the first to third aspects, in which a position of the air inlet 28i in the combustion chamber axis direction Dc differs between the target burner groups 26 which are adjacent to each other in the circumferential direction Dcc.

[0082] (5) The combustion chamber according to a fifth aspect is the combustion chamber 20 according to an aspect of the first to fourth aspects, in which a distance in the combustion chamber axis direction Dc from the air inlet 28i of the airflow path frame 28 to the fuel injection port 29o of the nozzle 29, which injects the fuel into the airflow path frame 28, is the same between the multiple target burner groups 26.

[0083] (6) The combustion chamber according to a sixth aspect is the combustion chamber 20 according to an aspect of the first to fifth aspects, in which the positions of the mixture outlets 28o of all airflow path frames 28 in the combustion chamber axis direction Dc are equal to each other.

[0084] (7) The combustion chamber according to a seventh aspect is the combustion chamber 20 according to an aspect of the first to sixth aspects, wherein the multiple burner groups 26 comprise multiple target burner groups 26 arranged in one region of an inner region 24i containing the combustion chamber axis Ac and an annular outer region 24o adjoining the inner region 24i on an outer circumferential side, and a burner group 26 arranged in the other region. The mixture flow path length Lm is different between the multiple target burner groups 26 arranged in one region and the burner group 26 arranged in the other region.

[0085] In the present configuration, the multiple target burners 27 are arranged in an area of ​​the inner region 24i and the outer region 24o, and the mixture flow path length differs between the target burner groups 26 that are adjacent to each other in the circumferential direction Dcc. Therefore, even in this configuration, it is possible to suppress the occurrence of combustion oscillation in the inner and outer oscillation mode described above, which leads to damage to the burner 27 or the cylinder 22.

[0086] Among the several modes of combustion vibration, in addition to the internal and external vibration modes described above, a circumferential vibration mode is representative. In this mode, several nodes extending radially with respect to the combustion chamber axis Ac are formed within the cylinder 22. In the circumferential vibration mode, the cylinder 22 is divided into several regions in the circumferential direction Dcc with respect to the combustion chamber axis Ac by these nodes, and the amplitude directions in two regions adjacent to each other in the circumferential direction Dcc are opposite. In this scenario, the mixture flow path length Lm differs between the multiple target burner groups 26 located in one region of the inner area 24i and the outer area 24o, and the burner group 26 located in the other region.Therefore, in the present aspect, the occurrence of combustion vibration in the circumferential vibration mode can also be suppressed.

[0087] (8) The combustion chamber according to an eighth aspect is the combustion chamber 20 according to aspects one through six, wherein the multiple burner groups 26 comprise multiple outer burner groups 26o, which are the multiple target burner groups 26, arranged in an annular outer area 24o adjacent to an inner area 24i containing the combustion chamber axis Ac on an outer circumferential side, and multiple inner burner groups 26i arranged in the inner area 24i. The multiple inner burner groups 26i are arranged in the circumferential direction Dcc with respect to the combustion chamber axis Ac. The mixture flow path length Lm is different between the inner burner groups 26i that are adjacent to each other in the circumferential direction Dcc.

[0088] In this aspect, the mixture flow path length Lm differs between the outer burner groups 26o, which are adjacent to each other in the circumferential direction Dcc. Furthermore, in this aspect, the mixture flow path length Lm differs between the inner burner groups 26i, which are adjacent to each other in the circumferential direction Dcc. Therefore, in this aspect, it is possible to suppress the occurrence of combustion oscillation in the internal and external oscillation modes described above, which leads to damage to the burner 27 or the cylinder 22, in both the outer area 24o and the inner area 24i.

[0089] (9) The combustion chamber according to a ninth aspect is the combustion chamber 20 according to the eighth aspect, wherein the outer area 24o has an outer circumferentially subdivided area 25o for each of the multiple outer burner groups 26o, arranged in the circumferential direction Dcc, and an outer boundary line 24oB for each of the multiple outer burner groups 26o, arranged in the circumferential direction Dcc. The outer boundary line 24oB for each of the multiple outer burner groups 26o is a boundary line between the outer circumferentially subdivided areas 25o that are adjacent to each other in the circumferential direction Dcc and extends in a direction having a radial component with respect to the combustion chamber axis Ac.The inner region 24i has an inner circumferentially subdivided region 25i for each of the multiple inner burner groups 26i, arranged in the circumferential direction Dcc, and an inner boundary line 24iB for each of the multiple outer burner groups 26o, also arranged in the circumferential direction Dcc. The inner boundary line 24iB for each of the multiple inner burner groups 26i is a boundary line between the inner circumferentially subdivided regions 25i that are adjacent to each other in the circumferential direction Dcc and extends in a direction that has a radial component with respect to the combustion chamber axis Ac. A position of the inner boundary line 24iB for each of the multiple inner burner groups 26i in the circumferential direction Dcc differs from a position of the outer boundary line 24oB for each of the multiple outer burner groups 26o in the circumferential direction Dcc.

[0090] In the present aspect, the position of each inner boundary line 24iB in the circumferential direction Dcc differs from the position of each outer boundary line 24oB in the circumferential direction Dcc. Therefore, since the mixture flow path lengths Lm between the outer area 24o and the inner area 24i do not completely coincide, it is possible to suppress the occurrence of combustion oscillation in the circumferential oscillation mode.

[0091] (10) The combustion chamber according to a tenth aspect is the combustion chamber 20 according to aspects one through nine, which further comprises an air hole plate 23 having a downstream end face 23ds facing the combustion chamber towards the downstream side Dcd, an upstream end face 23us facing the upstream side Dcu, and several air holes 23h penetrating from the upstream end face 23us to the downstream end face 23ds. An inner circumferential surface of the airflow path frame 28 for each of the several burners 27 is formed by an inner circumferential surface of any one of the several air holes 23h. The air inlet 28i is open at the upstream end face 23us of the air hole plate 23. The mixture outlet 28o is open at the downstream end surface 23ds of the air hole plate 23.The air hole plate 23 has several circumferentially subdivided areas 25, which are arranged in the circumferential direction Dcc with respect to the combustion chamber axis Ac. Any one of the multiple target burner groups 26 is provided for each of the multiple circumferentially subdivided areas 25.

[0092] For example, the airflow path frame 28 of each burner 27 can be formed from a tube. In this case, it is necessary to manufacture a tube for each of the multiple burners 27 and to position the tube for each of the multiple burners 27 in a suitable location. On the other hand, since the airflow path frame 28 for each of the multiple burners 27 is integrated by the air hole plate 23, manufacturing costs can be reduced in this aspect.

[0093] (11) The combustion chamber according to an eleventh aspect is the combustion chamber 20 according to the tenth aspect, in which, in a region where a transition occurs in the upstream end face 23us from one circumferentially subdivided area 25 to the other circumferentially subdivided area 25 of two circumferentially subdivided areas 25 which are adjacent to each other in the circumferential direction Dcc, the position of the upstream end face 23us changes stepwise in the combustion chamber axis direction Dc.

[0094] For example, in the embodiments and modification examples described above, the gas turbine is understood as follows.

[0095] (12) A gas turbine according to a twelfth aspect comprises The combustion chamber 20, according to one aspect from the first to the eleventh aspect, includes a compressor 10 capable of compressing air to generate compressed air, and a turbine 15 that can be driven by combustion gas generated by burning fuel in the combustion chamber. The airflow path frame 28 for each of the multiple burner groups 26 in the combustion chamber 20 is configured to allow the compressed air from the compressor 10 to flow from the air inlet 28i into the airflow path frame 28. Industrial applicability

[0096] According to one aspect of the present disclosure, it is possible to react flexibly to a fluctuation in a required performance from the outside. Reference symbol list 1 gas turbine 2 gas turbine rotor 3 intermediate housings 10 Compressor 11 Compressor rotor 12 compressor housings 15 Turbine 16 turbine rotor 17 turbine housings 20 Combustion chamber 21i inner cylinder 210 External cylinder 21e End cover 22 combustion cylinders (or simply cylinders) 23 air hole plate 23µs upstream end face 23ds downstream end face 23h air hole 24i Interior 24iB inner boundary 24-hour outdoor area 24oB outer boundary line 25 area subdivided in the circumferential direction 25a first area subdivided in the circumferential direction 25b second area subdivided circumferentially 25c third area subdivided circumferentially 25d fourth circumferentially subdivided area 25e fifth circumferentially subdivided area 25f sixth circumferentially subdivided area 25i inner circumferentially subdivided area 25ia inner first circumferentially subdivided area 25 lb inner second circumferentially subdivided region 25ic inner third circumferentially subdivided area 25id inner fourth circumferentially subdivided region 25ie inner fifth circumferentially subdivided area 25if inner sixth circumferentially subdivided region 25° outer circumferentially subdivided area 25oa outer first circumferentially subdivided area 25ob outer second circumferentially subdivided area 25oc outer third circumferentially subdivided area 25od outer fourth circumferentially subdivided region 25oe outer fifth circumferentially subdivided area 25 of outer sixth circumferentially subdivided area 26 burner group 26a first burner group 26b second burner group 26c third burner group 26d fourth burner group 26e fifth burner group 26f sixth burner group 26i inner burner group 26ia inner first burner group 26ib inner second burner group 26ic inner third burner group 26id inner fourth burner group 26 the inner fifth burner group 26if inner sixth burner group 26o outer burner group 26oa outer first burner group 26ob outer second burner group 26oc outer third burner group 26od outer fourth burner group 26oe outer fifth burner group 26 of outer sixth burner group 27 burners 28 Airflow path frames 28i air intake 28° mixture outlet 29 nozzle 29o Fuel injection port 30 Fuel supply system 31 Main fuel line 32 Branch fuel pipeline A air Acom compressed air Fuel CG combustion gas Nc, No: Node Ar Rotor axis Ac combustion chamber axis Since rotor axis direction Dau axial upstream side Dad axial downstream side DC combustion chamber axis direction Dcu upstream side DCD downstream side DCC circumferential direction La airflow path length Lm mixture flow path length Li insertion length QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2023-115975

[0002] JP 2014-173840

[0005]

Claims

[1] Combustion chamber, comprising: a cylinder having a cylindrical shape around a combustion chamber axis and in which a combustion chamber, in which fuel can be burned, is formed on an inner circumferential side; and several burner groups, whereby Each of the multiple burner groups has several burners capable of injecting fuel along with compressed air into the cylinder, Each of the multiple burners has an airflow path frame capable of allowing air to flow and injecting air into the cylinder, and a nozzle in which a fuel injection orifice is formed through which fuel can be injected into the airflow path frame. the airflow path frame has an air inlet that is open at one end of the airflow path frame on an upstream side in a combustion chamber axis direction in which the combustion chamber axis extends, and a mixture outlet that is open at one end of the airflow path frame on a downstream side in the combustion chamber axis direction, several target burner groups, which are multiple burner groups of at least some of the multiple burner groups, are arranged in a circumferential direction with respect to the combustion chamber axis, and a mixture flow path length, which is a distance in the combustion chamber axis direction from the fuel injection opening of the nozzle to the mixture outlet of the air flow path frame, into which fuel is injected from the fuel injection opening, is different between the target burner groups that are adjacent to each other in the circumferential direction. [2] Combustion chamber according to claim 1, wherein the number of multiple target burner groups is three or more. [3] Combustion chamber according to claim 1, wherein a lateral angle in the circumferential direction with respect to the combustion chamber axis is the same between the multiple target burner groups for each of the multiple target burner groups. [4] Combustion chamber according to claim 1, wherein the position of the air inlet in the combustion chamber axis direction is different between the target burner groups which are adjacent to each other in the circumferential direction. [5] Combustion chamber according to claim 1, wherein the distance in the combustion chamber axis direction from the air inlet of the airflow path frame to the fuel injection opening of the nozzle injecting the fuel into the airflow path frame is the same between the multiple target burner groups. [6] Combustion chamber according to claim 1, wherein the positions of the mixture outlets of all airflow path frames are the same in the combustion chamber axis direction. [7] Combustion chamber according to claim 1, wherein the multiple burner groups, multiple target burner groups arranged in one area of ​​an inner region containing the combustion chamber axis and an annular outer region adjoining the inner region on an outer circumferential side, and a burner group arranged in the other region, and the mixture flow path length differs between the multiple target burner groups located in one area and the burner group located in the other area. [8] Combustion chamber according to claim 1, wherein the multiple burner groups, multiple outer burner groups, which are the multiple target burner groups, which are arranged in an annular outer area adjacent to an inner area containing the combustion chamber axis on an outer circumferential side, and multiple inner burner groups, which are arranged in the inner area, the several inner burner groups are arranged in the circumferential direction with respect to the combustion chamber axis, and The mixture flow path length differs between the inner burner groups that are adjacent to each other in the circumferential direction. [9] Combustion chamber according to claim 8, wherein the exterior area has an outer circumferentially subdivided area for each of the several outer burner groups, arranged in the circumferential direction, and an outer boundary line for each of the several outer burner groups, arranged in the circumferential direction, the outer boundary line for each of the several outer burner groups is a boundary line between the outer circumferentially subdivided areas that are adjacent to each other in the circumferential direction and extends in a direction that has a radial component with respect to the combustion chamber axis, the interior area has an inner circumferentially subdivided area for each of the several inner burner groups, arranged in the circumferential direction, and an inner boundary line for each of the several outer burner groups, arranged in the circumferential direction, the inner boundary line for each of the several inner burner groups is a boundary line between the inner circumferentially subdivided areas that are adjacent to each other in the circumferential direction and extends in a direction that has a radial component with respect to the combustion chamber axis, and a position of the inner boundary line for each of the several inner burner groups in the circumferential direction differs from a position of the outer boundary line for each of the several outer burner groups in the circumferential direction. [10] Combustion chamber according to any one of claims 1 to 9, further comprising: an air hole plate having a downstream end face facing the combustion chamber towards the downstream side, an upstream end face facing the upstream side, and several air holes penetrating from the upstream end face to the downstream end face, wherein an inner circumferential surface of the airflow path frame for each of the multiple burners is formed by an inner circumferential surface of any one of the multiple air holes, the air inlet is open at the upstream end face of the air hole plate, the mixture outlet is open at the downstream end face of the air hole plate, The air hole plate has several circumferentially subdivided areas that are arranged circumferentially with respect to the combustion chamber axis, and Any target burner group of the several target burner groups is provided for each of the several circumferentially subdivided areas. [11] Combustion chamber according to claim 10, wherein in a region in which a transition from one circumferentially subdivided region to the other circumferentially subdivided region of two circumferentially subdivided regions which are adjacent to each other in the circumferential direction takes place in the upstream end surface, the position of the upstream end surface changes stepwise in the direction of the combustion chamber axis. [12] Gas turbine, comprising: the combustion chamber according to claim 1; a compressor capable of compressing air to produce compressed air; and a turbine that can be driven by combustion gas produced by burning fuel in the combustion chamber, wherein The airflow path frame for each of the multiple burner groups in the combustion chamber is configured to allow the compressed air from the compressor to flow from the air inlet into the airflow path frame.

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