Combustion burners, and gas turbines equipped with such combustors

Abstract

The burner of the present invention includes: an inner cylinder; a burner nozzle disposed on the inner circumferential side of the inner cylinder; a tail cylinder for allowing combustion gases to flow; and an anti-backflow member extending circumferentially relative to the burner axis, disposed on the inner circumferential side of the tail cylinder and fixed to the tail cylinder. The upstream end of the tail cylinder, including the upstream end of the tail cylinder, is radially opposed to the downstream end of the inner cylinder, i.e., the downstream end of the inner cylinder, separated by the interval. The upstream end of the tail cylinder has a plurality of air holes at a position closer to the upstream end than the downstream end of the inner cylinder. The anti-backflow member has a reduced diameter portion whose inner diameter gradually decreases towards the downstream side. The position of the most downstream end of the reduced diameter inner circumferential surface, i.e., the reduced diameter inner circumferential surface, closest to the downstream side, is located closer to the downstream side than the downstream end of the inner cylinder.

Description

Technical Field

[0001] The present invention relates to a burner and a gas turbine having the burner.

[0002] This application claims priority based on Japanese Patent Application No. 2024-073510, filed on April 30, 2024, the contents of which are incorporated herein by reference. Background Technology

[0003] A gas turbine includes: a compressor that generates compressed air; a combustor that generates combustion gases by burning fuel in the compressed air from the compressor; and a turbine that is driven by the combustion gases.

[0004] Patent Document 1 discloses a combustor for a gas turbine as described above. This combustor includes: an inner cylinder, cylindrical about an axis; a combustor nozzle disposed on the inner circumference of the inner cylinder, capable of injecting fuel and air downstream in the axial direction; and a tail cylinder, cylindrical about an axis, which allows fuel from the combustor nozzle to burn in air and facilitates the flow of combustion gases generated during fuel combustion. The inner diameter of the upstream side portion of the tail cylinder, including the upstream end, is larger than the outer diameter of the downstream side portion of the inner cylinder, including the downstream end. The upstream side portion of the tail cylinder is radially spaced apart from the outer circumferential surface of the downstream side portion of the inner cylinder. In other words, the cylindrical downstream side portion of the inner cylinder is inserted into the cylindrical upstream side portion of the tail cylinder.

[0005] In the burner disclosed in Patent Document 1, the thermal expansion difference between the tail tube and the inner tube is allowed, and the vibration of the tail tube relative to the inner tube is also allowed. Therefore, a sealing component called a spring clip and a bag clip is arranged between the inner circumference of the upstream side of the tail tube and the outer circumference of the downstream side of the inner tube. Moreover, in this burner, an anti-backflow structure is adopted to suppress damage to the sealing component caused by the backflow of combustion gas in the tail tube.

[0006] Patent document 1 discloses several anti-backflow structures.

[0007] Specifically, for example, the first anti-backflow structure includes: a plurality of air holes extending from the outer peripheral side to the inner peripheral side of the tailstock upstream side; a guide portion guiding air flowing from the plurality of air holes between the plurality of air holes and the inner cylinder downstream side along the inner peripheral surface of the tailstock upstream side to the downstream side; and a throttling portion disposed between the tailstock upstream side and the inner cylinder downstream side and closer to the downstream side than the plurality of air holes and the guide portion. The plurality of air holes are arranged at intervals in the circumferential direction relative to the burner axis. The throttling portion extends radially inward from the inner peripheral surface of the tailstock upstream side relative to the burner axis.

[0008] Between the upstream side of the tailstock and the downstream side of the inner cylinder, air flows in through the elastic member and from multiple air holes. This air flows into the tailstock through the gap between the throttling section and the outer peripheral surface of the downstream side of the inner cylinder. In this first anti-backflow structure, the gap on the downstream side between the upstream side of the tailstock and the downstream side of the inner cylinder is narrowed by the throttling section, thereby suppressing the flow of combustion gases between the upstream side of the tailstock and the downstream side of the inner cylinder, and the throttling section is cooled by air from the multiple air holes. Furthermore, the air flowing into the tailstock through the gap between the throttling section and the outer peripheral surface of the downstream side of the inner cylinder also functions as an air curtain against the backflow of combustion gases.

[0009] Furthermore, for example, the second anti-backflow structure includes: a plurality of air holes extending from the outer circumference to the inner circumference of the tailpipe upstream side; and a throttling section disposed at the outlet of each of the plurality of air holes. The plurality of air holes are arranged at intervals in the circumferential direction relative to the burner axis. A flow path for airflow from the plurality of air holes is formed in the throttling section. Each of the plurality of air holes is provided with this flow path. Each flow path is inclined radially relative to the burner axis.

[0010] Air passing through the aforementioned elastic component flows into the tailpipe via the gap between the throttling section and the outer peripheral surface of the downstream side of the inner cylinder. Furthermore, air from the multiple air holes flows into the tailpipe through their respective flow paths. This air is injected into the tailpipe from the throttling section radially inward and downstream relative to the burner axis. In this second anti-backflow structure, the gap between the upstream side of the tailpipe and the downstream side of the inner cylinder is narrowed by the throttling section, thereby suppressing the flow of combustion gases between the upstream side of the tailpipe and the downstream side of the inner cylinder, and the throttling section is cooled by air from the multiple air holes. Furthermore, the air injected into the tailpipe from the throttling section also functions as an air curtain against backflowing combustion gases.

[0011] Existing technical documents

[0012] Patent documents

[0013] Patent Document 1: International Publication No. 2012 / 132898 Summary of the Invention

[0014] The problem that the invention aims to solve

[0015] In the anti-backflow structure described in Patent Document 1, the inflow of combustion gases between the upstream side of the tail cylinder and the downstream side of the inner cylinder can be suppressed. However, it is desirable to further suppress the inflow of combustion gases between the upstream side of the tail cylinder and the downstream side of the inner cylinder. Therefore, in order to further suppress the inflow of combustion gases, a method can be considered to increase the flow rate of air flowing out of the air holes, for example, by increasing the inner diameter of the multiple air holes or increasing the number of air holes. In this method, the amount of air flowing into the inner cylinder and used for combustion is reduced, thus increasing the air-fuel ratio in the combustion zone, thereby causing an increase in NOx or a combustion instability phenomenon known as combustion vibration.

[0016] The present invention was made in consideration of the above circumstances, and its object is to provide a burner that can efficiently suppress the flow of combustion gas into the gap between the tail tube and the inner tube, and a gas turbine equipped with the burner.

[0017] Methods for solving problems

[0018] A burner according to one aspect of the present invention for achieving the aforementioned objective comprises:

[0019] The burner comprises an inner cylinder, cylindrical in shape around the burner axis; a burner nozzle, disposed on the inner circumference of the inner cylinder, capable of injecting fuel and air downstream in both the upstream and downstream directions along the axial direction extending from the burner axis; a tail cylinder, cylindrical in shape around the burner axis, allowing fuel from the burner nozzle to burn in air and facilitating the flow of combustion gases generated during fuel combustion; and an anti-backflow component, extending circumferentially relative to the burner axis, disposed on the inner circumference of the tail cylinder and fixed to the tail cylinder. The inner diameter of the upstream side portion of the tail cylinder, including the upstream end, is larger than the outer diameter of the downstream side portion of the inner cylinder, including the downstream end. The upstream side portion of the tail cylinder is positioned radially spaced from the outer circumference of the downstream side portion of the inner cylinder relative to the burner axis. The upstream side of the tail cylinder has a plurality of air holes located closer to the upstream side than the downstream end of the inner cylinder. These air holes are spaced apart in the circumferential direction and extend from the outer circumferential side to the inner circumferential side of the upstream side of the tail cylinder. Each air hole has an inlet opening on the outer circumferential surface of the upstream side of the tail cylinder and an outlet opening on the inner circumferential surface of the upstream side of the tail cylinder. The anti-backflow component includes: a reduced-diameter portion whose inner diameter gradually decreases towards the downstream side; and a connecting portion that connects to the upstream end of the reduced-diameter portion and engages with the upstream side of the tail cylinder at a position closer to the downstream side than the outlets of the respective air holes. The downstream end of the reduced-diameter portion, located closest to the downstream side on the inner circumferential surface of the reduced-diameter portion, is positioned closer to the downstream side than the downstream end of the inner cylinder.

[0020] The gas flow path (combustion gas, or air and fuel) widens sharply from the downstream end of the inner cylinder, thus creating a gas vortex on the downstream side of the inner cylinder. Consequently, the combustion gas in the tail cylinder flows backward, and there is a possibility that the combustion gas may flow into the cylindrical gap between the upstream side of the tail cylinder and the downstream side of the inner cylinder. Assuming a sealing element is installed in this cylindrical gap, there is a risk of damage to the sealing element if the combustion gas flows into this gap.

[0021] In this method, the narrowing of the anti-backflow component reduces the gap between the upstream side of the tail cylinder and the downstream side of the inner cylinder, thereby suppressing the flow of combustion gas into the cylindrical gap. Furthermore, in this method, air from multiple air holes flows along the inner circumferential surface of the narrowing section, cooling the narrowing section and thus suppressing thermal damage to it.

[0022] In this method, the air streams from multiple circumferentially arranged air holes flow downstream and then along the inner circumferential surface of the constricted diameter, gradually dispersing circumferentially as they reach the downstream end of the constricted diameter. Therefore, in this method, the air flowing along the inner circumferential surface of the constricted diameter is injected into the tailpipe in a substantially uniform circumferential direction. Thus, the air injected into the tailpipe functions as a suitable air curtain against the counter-flowing combustion gases.

[0023] In this method, after flowing along the inner circumferential surface of the constricted diameter, the air injected into the tailpipe has a downstream directional component and a radially inward directional component. Therefore, in this method, the air with the downstream directional component can suppress the combustion gas flowing upstream from further upstream. Moreover, in this method, the air with the radially inward component can guide the combustion gas flowing into the cylindrical gap to the radially inward side.

[0024] Therefore, in this method, the flow of combustion gas from the tail cylinder into the cylindrical gap between the upstream side of the tail cylinder and the downstream side of the inner cylinder can be suppressed with extremely high efficiency.

[0025] To achieve the aforementioned objective, the gas turbine of one aspect of the present invention comprises:

[0026] The embodiment includes a burner; a compressor capable of generating compressed air by compressing air; a turbine driven by combustion gases from the burner; and an intermediate housing allowing compressed air from the compressor to flow in. The compressor has: a compressor rotor capable of rotating about a rotor axis; and a compressor housing for covering the compressor rotor. The turbine has: a turbine rotor capable of rotating about the rotor axis; and a turbine housing for covering the turbine rotor. The compressor rotor and the turbine rotor are interconnected to form a gas turbine rotor. The intermediate housing is located between the compressor housing and the turbine housing. The compressor housing, the intermediate housing, and the turbine housing are interconnected to form a gas turbine housing. The burner is mounted on the intermediate housing so that compressed air within the intermediate housing can flow into the burner.

[0027] Invention Effects

[0028] According to one aspect of the present invention, it is possible to efficiently suppress the flow of combustion gases into the gap between the tail cylinder and the inner cylinder. Attached Figure Description

[0029] Figure 1 This is a schematic cross-sectional view of a gas turbine in one embodiment of the present invention.

[0030] Figure 2 This is a cross-sectional view around the burner of a gas turbine in one embodiment of the present invention.

[0031] Figure 3 This is a cross-sectional view of the main part of the burner in one embodiment of the present invention.

[0032] Figure 4 yes Figure 3 An enlarged sectional view of the main part of the structure.

[0033] Figure 5 yes Figure 3 A sectional view taken along line VV. Detailed Implementation

[0034] Hereinafter, with reference to the accompanying drawings, a detailed description will be given of an embodiment of the burner and the gas turbine equipped with the burner according to the present invention.

[0035] "Implementation Methods of Gas Turbines"

[0036] refer to Figure 1 The gas turbine in this embodiment will be described.

[0037] The gas turbine in this embodiment includes: a compressor 10 capable of generating compressed air Acom by compressing air A; a plurality of burners 30 capable of generating combustion gas CG by burning fuel F in compressed air Acom; a turbine 20 capable of being driven by the high-temperature and high-pressure combustion gas CG; and an intermediate casing 6.

[0038] The compressor 10 includes: a compressor rotor 11 capable of rotating about a rotor axis Ar; a compressor housing 18 for covering the compressor rotor 11; and a plurality of stator vanes 15. The turbine 20 includes: a turbine rotor 21 capable of rotating about a rotor axis Ar; a turbine housing 28 for covering the turbine rotor 21; and a plurality of stator vanes 25. Hereinafter, the direction in which the rotor axis Ar extends is defined as the rotor axis direction Dr, one side of which is defined as the upstream rotor axis side Dru, and the other side as the downstream rotor axis side Drrd. Furthermore, the radial direction relative to the rotor axis Ar is simply referred to as the radial direction Drr, and on this radial direction Drr, the side closer to the rotor axis Ar is defined as the radial inner side Drri, and the side farther from the rotor axis Ar is defined as the radial outer side Drro.

[0039] The compressor 10 is positioned on the upstream side of the rotor shaft relative to the turbine 20.

[0040] The compressor rotor 11 and turbine rotor 21 are located on the same rotor axis Ar and are interconnected to form the gas turbine rotor 1. For example, a generator rotor GEN is connected to this gas turbine rotor 1. The aforementioned intermediate housing 6 is disposed between the compressor housing 18 and the turbine housing 28 along the rotor axis Dr. The compressor housing 18, intermediate housing 6, and turbine housing 28 are interconnected to form the gas turbine housing 8. Compressed air from the compressor 10 can flow into the intermediate housing 6.

[0041] The compressor rotor 11 includes: a rotor shaft 12 extending about a rotor axis Ar and along the rotor axis direction Dr; and a plurality of moving vane cascades 13 mounted on the rotor shaft 12. The plurality of moving vane cascades 13 are arranged along the rotor axis direction Dr. Each moving vane cascade 13 is composed of a plurality of moving blades arranged circumferentially relative to the rotor axis Ar. Downstream of each of the plurality of moving vane cascades 13 on the rotor axis direction Dr, one of a plurality of stationary vane cascades 15 is disposed. Each stationary vane cascade 15 is located inside the compressor housing 18. Each stationary vane cascade 15 is composed of a plurality of stationary blades arranged circumferentially relative to the rotor axis Ar.

[0042] The turbine rotor 21 includes: a rotor shaft 22 extending about a rotor axis Ar and along the rotor axis direction Dr; and a plurality of moving blade cascades 23 mounted on the rotor shaft 22. The plurality of moving blade cascades 23 are arranged along the rotor axis direction Dr. Each moving blade cascade 23 is composed of a plurality of moving blades arranged circumferentially relative to the rotor axis Ar. On the upstream side Dru of each of the plurality of moving blade cascades 23 along the rotor axis, any one of a plurality of stator blade cascades 25 is disposed. Each stator blade cascade 25 is disposed inside the turbine housing 28. Each stator blade cascade 25 is composed of a plurality of stator blades arranged circumferentially relative to the rotor axis Ar.

[0043] Multiple burners 30 are arranged circumferentially relative to the rotor axis Ar and mounted on an intermediate housing 6 so that compressed air Acom inside the intermediate housing 6 can flow into the burners 30.

[0044] Compressor 10 generates compressed air Acom by compressing air A. This compressed air Acom flows into combustor 30 via intermediate casing 6. Fuel F is supplied to combustor 30. Within combustor 30, fuel F is burned in compressed air Acom to generate high-temperature, high-pressure combustion gas CG. This combustion gas CG is delivered from combustor 30 to turbine casing 28. As the combustion gas CG flows downstream of rotor axis Drd within turbine casing 28, it causes turbine rotor 21 to rotate. The rotation of turbine rotor 21 causes the rotor of generator GEN, connected to gas turbine rotor 1, to rotate. As a result, generator GEN generates electricity.

[0045] The following is a detailed description of the implementation method of the burner 30.

[0046] "Implementation Methods of the Burner"

[0047] refer to Figures 2-5 The burner in this embodiment will be described.

[0048] like Figure 2As shown, the burner 30 in this embodiment includes: an inner cylinder 32, which is cylindrical around the burner axis Ac; a plurality of burner nozzles 31 disposed on the inner circumference of the inner cylinder 32; and a tail cylinder 42, which is cylindrical around the burner axis Ac and allows the combustion gases CG generated during fuel combustion to flow through it. Hereinafter, the direction in which the burner axis Ac extends is defined as the axial direction Dc, one side of the axial direction Dc is defined as the upstream side Dcu, and the other side is defined as the downstream side Dcd. Furthermore, the radial direction relative to the burner axis Ac is simply referred to as the radial direction Dcr, and on this radial direction Dcr, the side closer to the burner axis Ac is defined as the radial inner side Dcri, and the side farther from the burner axis Ac is defined as the radial outer side Dcro. Moreover, the circumferential direction centered on the burner axis Ac is simply referred to as the circumferential direction Dcc.

[0049] The burner axis Ac lies on an imaginary plane containing the rotor axis Ar. Furthermore, the upstream side Dcu of the burner axis Ac in the axial direction Dc corresponds to the upstream side Dru of the rotor axis in the rotor axial direction Dr, while the downstream side Dcd of the burner axis Ac in the axial direction Dc corresponds to the downstream side Drd of the rotor axis in the rotor axial direction Dr. However, the burner axis Ac is inclined relative to the rotor axis Ar, so that it gradually approaches the rotor axis Ar as it moves downstream towards the rotor axis Ar.

[0050] Both the inner cylinder 32 and the tail cylinder 42 are disposed within the intermediate housing 6. Therefore, compressed air Acom from the compressor 10 flows on the outer periphery of the inner cylinder 32 and the tail cylinder 42.

[0051] Compressed air Acom flows into the inner cylinder 32 from its upstream side Dcu. Each burner nozzle 31, disposed within the inner cylinder 32, can eject externally supplied fuel F along with the compressed air Acom flowing into the inner cylinder 32 towards the upstream side Dcu. The downstream end Dcd of each burner nozzle 31 is located closer to the upstream side Dcu than the downstream end 32de of the inner cylinder 32. In the tailpipe 42, fuel F from the multiple burner nozzles 31 burns in the compressed air Acom, generating high-temperature, high-pressure combustion gas CG. This combustion gas CG flows downstream Dcd within the tailpipe 42 and into the turbine housing 28. Therefore, the tailpipe 42 defines the combustion gas flow path for the combustion gas CG. Additionally, in the region within the inner cylinder 32 closer to the downstream Dcd than each burner nozzle 31, fuel F from the burner nozzles 31 may sometimes also burn in the compressed air Acom.

[0052] The inner diameter of the upstream side portion 43 of the tail cylinder, which includes the upstream end Dcu of the tail cylinder 42 (i.e., the upstream end 42ue of the tail cylinder), is larger than the outer diameter of the downstream side portion 33 of the inner cylinder, which includes the downstream end Dcd of the inner cylinder 32 (i.e., the downstream end 32de of the inner cylinder). The upstream side portion 43 of the tail cylinder is positioned opposite to the outer peripheral surface 33o of the downstream side portion 33 of the inner cylinder, spaced apart. In other words, the cylindrical downstream side portion 33 of the inner cylinder is inserted into the cylindrical upstream side portion 43 of the tail cylinder.

[0053] The cross-sectional area of ​​the tailstock 42 perpendicular to the burner axis Ac gradually decreases from the upstream side Dcu within the tailstock 42, closer to the downstream side Dcd than the upstream side portion 43, i.e., the throttling start position 46, towards the downstream side Dcd. Here, in the tailstock 42, the portion located radially outward (Drro) relative to the rotor axis Ar, closer to the burner axis Ac, and facing the inner circumference of the intermediate casing 6, is designated as the casing opposing portion 47. Furthermore, in the tailstock 42, the portion located radially inward (Drri) relative to the rotor axis Ar, closer to the burner axis Ac, and facing the gas turbine rotor 1, is designated as the rotor opposing portion 49. As described above, since the burner axis Ac is inclined relative to the rotor axis Ar, the casing opposing portion 47 and the rotor opposing portion 49 are also inclined relative to the rotor axis Ar, so that they gradually approach the rotor axis Ar towards the downstream side Dcd. However, closer to the downstream side Dcd than the aforementioned throttling start position 46, the inclination of the housing opposition portion 47 relative to the rotor axis Ar is greater than that of the rotor opposition portion 49 relative to the rotor axis Ar. Therefore, in the cross-section of the tail cylinder 42 formed by the aforementioned imaginary plane including the rotor axis Ar, the portion closer to the downstream side Dcd than the throttling start position 46 in the housing opposition portion 47, i.e., the throttling portion 48, is inclined relative to the portion closer to the upstream side Dcu than the throttling start position 46 in the housing opposition portion 47.

[0054] like Figure 3 As shown, the burner 30 in this embodiment further includes a first elastic ring 50, a second elastic ring 55, an air guide component 60, and an anti-backflow component 65. The first elastic ring 50 is sometimes referred to as a sealing clip. The second elastic ring 55 is sometimes referred to as a spring clip.

[0055] The first elastic ring 50 and the second elastic ring 55 are as follows Figure 3 and Figure 4 As shown, both are cylindrical around the burner axis Ac. Furthermore, the first elastic ring 50 and the second elastic ring 55 are both disposed in the cylindrical gap 40 between the inner circumferential surface 43i of the upstream side portion 43 of the cylindrical tail tube and the outer circumferential surface 33o of the downstream side portion 33 of the cylindrical inner tube.

[0056] The second elastic ring 55 has: a cylindrical fixing portion 56 fixed to the outer peripheral surface 33o of the downstream side portion 33 of the inner cylinder; and a spring portion 57 integrally formed with the fixing portion 56 and extending from the fixing portion 56 in a direction having a component of the axial direction Dc. The spring portion 57 has a contact portion 59 that contacts the inner peripheral surface 43i of the upstream side portion 43 of the tail cylinder. Since the fixing portion 56 contacts the outer peripheral surface 33o of the downstream side portion 33 of the inner cylinder, its inner diameter is substantially the same as the outer diameter of the downstream side portion 33 of the inner cylinder. On the other hand, since the contact portion 59 in the spring portion 57 contacts the inner peripheral surface 43i of the upstream side portion 43 of the tail cylinder, its outer diameter is larger than the outer diameter of the fixing portion 56. The spring portion 57 extends from the fixing portion 56 in a direction having a component of the direction toward the upstream side Dcu. The contact portion 59 of the spring portion 57 is located on the upstream side Dcu of the fixing portion 56 and is located radially outward Dcro.

[0057] In the spring portion 57 of the second elastic ring 55, a plurality of slits 58 are formed at equal intervals on the circumferential Dcc, which penetrate in the radial Dcr and extend along the axial direction Dc (see reference). Figure 3 The slit 58 is formed at the position from the upstream end to the downstream end of the spring portion 57. The slit 58 is formed to cope with the following: due to the difference in thermal expansion between the inner cylinder 32 and the tail cylinder 42, and the vibration of the tail cylinder 42, the position of the inner peripheral surface 43i of the upstream side portion 43 of the tail cylinder relative to the outer peripheral surface 33o of the downstream side portion 33 of the inner cylinder is displaced.

[0058] The first elastic ring 50 has: a cylindrical fixing portion 51 fixed to the outer peripheral surface 33o of the downstream side portion 33 of the inner cylinder; and a spring portion 52 integrally formed with the fixing portion 51 and extending from the fixing portion 51 along a direction having an axial direction Dc. The spring portion 52 of the first elastic ring 50 has: a first contact portion 54a that contacts the contact portion 59 of the second elastic ring 55; and a second contact portion 54b that contacts the outer peripheral surface 33o of the downstream side portion 33 of the inner cylinder. Since both the fixing portion 51 and the second contact portion 54b are in contact with the outer peripheral surface 33o of the downstream side portion 33 of the inner cylinder, their inner diameters are substantially the same as the outer diameter of the downstream side portion 33 of the inner cylinder. On the other hand, since the first contact portion 54a is in contact with the contact portion 59 of the second elastic ring 55, its outer diameter is larger than the outer diameters of the fixing portion 51 and the second contact portion 54b. The fixing portion 51 of the first elastic ring 50 is located closer to the upstream side Dcu than the fixing portion 56 of the second elastic ring 55 and closer to the downstream side Dcd than the contact portion 59 of the second elastic ring 55. The spring portion 52 of the first elastic ring 50 extends from the fixing portion 51 of the first elastic ring 50 along a direction having a directional component toward the upstream side Dcu. The first contact portion 54a of the spring portion 52 is located on the upstream side Dcu of the fixing portion 51 and is located radially outward Dcro. The second contact portion 54b of the spring portion 52 is located on the upstream side Dcu of the first contact portion 54a and is located radially inward Dcri.

[0059] In the spring portion 52 of the first elastic ring 50, a plurality of slits 53 are also formed at equal intervals on the circumferential Dcc, which penetrate in the radial Dcr and extend along the axial direction Dc (see reference). Figure 3 The slit 53 is also formed at the position from the upstream end to the downstream end of the spring part 52. The slit 53 is also formed to cope with the following: due to the difference in thermal expansion between the inner cylinder 32 and the tail cylinder 42, and the vibration of the tail cylinder 42, the position of the inner peripheral surface 43i of the upstream side of the tail cylinder 43 relative to the outer peripheral surface 33o of the downstream side of the inner cylinder 33 is displaced.

[0060] The first elastic ring 50 and the second elastic ring 55 described above are responsible for the following two functions.

[0061] First function: Allows relative displacement of the inner circumferential surface 43i of the upstream side 43 of the tail cylinder relative to the outer circumferential surface 33o of the downstream side 33 of the inner cylinder due to thermal expansion difference between the inner cylinder 32 and the tail cylinder 42, vibration of the tail cylinder 42, etc.

[0062] The second function is to prevent compressed air Acom located on the outer periphery of the inner cylinder 32 and the tail cylinder 42 from flowing into the cylindrical gap 40 from the gap between the upstream end 42ue of the tail cylinder and the downstream side 33 of the inner cylinder, and from flowing into the tail cylinder 42 from the gap between the upstream side 43 of the tail cylinder and the downstream end 32de of the inner cylinder. That is, to seal the compressed air Acom.

[0063] In addition, the first elastic ring 50 is mainly responsible for the first function, while the second elastic ring 55 is mainly responsible for the second function.

[0064] The upstream side portion 43 of the tail cylinder has a plurality of air holes 44. The plurality of air holes 44 extend from the outer peripheral side to the inner peripheral side of the upstream side portion 43. The plurality of air holes 44 are arranged at intervals along the circumferential direction Dcc within a closed region 41 in the cylindrical gap 40, and are located closer to the upstream side Dcu than the downstream end 32de of the inner cylinder. Furthermore, the closed region 41 is a region within the cylindrical gap 40 that inhibits the flow of compressed air Acom from the gap between the upstream end 42ue of the tail cylinder and the downstream side portion 33 of the inner cylinder into the cylindrical gap 40, passing through the second elastic ring 55 to the downstream side Dcd. Each of the plurality of air holes 44 has: an inlet 44i, opening on the outer peripheral surface 43o of the upstream side portion 43 of the tail cylinder; and an outlet 44o, opening on the inner peripheral surface 43i of the upstream side portion 43 of the tail cylinder.

[0065] The air guide member 60 guides air Acom, which flows from the plurality of air holes 44 into the enclosed region 41 of the cylindrical gap 40, along the inner circumferential surface 43i of the upstream side 43 of the tail cylinder to the downstream side Dcd. The air guide member 60 has a guide plate 61, a sealing plate 62, and a plurality of spaced retaining protrusions 63. The guide plate 61 extends circumferentially along the Dcc, positioned radially spaced from the region where the outlets 44o of the plurality of air holes 44 are formed, on the inner circumferential surface 43i of the upstream side 43 of the tail cylinder. The sealing plate 62, located closer to the upstream side Dcu than the outlets 44o of the plurality of air holes 44, seals the gap between the inner circumferential surface 43i of the upstream side 43 of the tail cylinder and the guide plate 61.

[0066] Multiple spaced retaining protrusions 63 protrude radially outward from the guide plate 61 at a position closer to the downstream side Dcd than the respective outlets 44o of the multiple air holes 44, and are spaced apart in the circumferential direction Dcc. The multiple spaced retaining protrusions 63 contact the inner circumferential surface 43i of the upstream side portion 43 of the tail cylinder to maintain the radial spacing Dcr between the guide plate 61 and the inner circumferential surface 43i of the upstream side portion 43 of the tail cylinder.

[0067] An anti-backflow component 65 is disposed on the inner circumferential side of the tailstock 42 and fixed to the tailstock 42. The anti-backflow component 65 has a reduced diameter portion 66 and a connecting portion 67. The reduced diameter portion 66 is formed to extend along the direction having the axial direction Dc component and the circumferential direction Dcc, and the inner diameter gradually decreases as it moves downstream towards the Dcd. The connecting portion 67 extends along the circumferential direction Dcc and extends from the end of the upstream side Dcu of the reduced diameter portion 66 towards the upstream side Dcu.

[0068] The upstream side portion 43 of the tailstock has a recess 45, which is located closer to the downstream side Dcd than the respective outlets 44o of the plurality of air holes 44. The recess 45 is recessed radially outward from the inner circumferential surface 43i of the upstream side portion 43 and extends along the circumferential direction Dcc. The depth of this recess 45 corresponds to the thickness on the radial direction Dcr of the engagement portion 67. The engagement portion 67 enters the recess 45 and engages with the upstream side portion 43 of the tailstock.

[0069] The aforementioned guide plate 61 extends to a position closer to the downstream side Dcd than the respective outlets 44o of the plurality of air holes 44 and closer to the upstream side Dcu than the reduced diameter portion 66 of the anti-backflow component 65.

[0070] The inner circumferential surface 66i of the reduced diameter portion 66 is inclined at an angle α of 30° or more and 60° or less relative to the outer circumferential surface 33o of the downstream side portion 33 of the inner cylinder. Specifically, in this embodiment, the inner circumferential surface 66i of the reduced diameter portion 66 is inclined at an angle α of 45° relative to the outer circumferential surface 33o of the downstream side portion 33 of the inner cylinder.

[0071] The downstream end 66de of the reduced diameter inner circumferential surface 66i, which is closest to the downstream side Dcd, is located closer to the downstream side Dcd than the downstream end 32de of the inner cylinder.

[0072] The downstream end 66de of the reduced diameter is located closer to the radially inner side Dcri than the position described below, which is the distance of half the gap g between the outer peripheral surface 33o of the downstream side 33 of the inner cylinder and the inner peripheral surface 43i of the upstream side 43 of the tail cylinder, located on the axial direction Dc from the inner peripheral surface 43i of the upstream side 43 of the tail cylinder to the downstream end 32de of the inner cylinder. Furthermore, this downstream end 66de is located closer to the radially outer side Dcro than the downstream end 32de of the inner cylinder.

[0073] The anti-backflow component 65 extending along the circumferential DCc as described above is as follows: Figure 5 As shown, it is located only at a position closer to the radial outer side Drro relative to the rotor axis Ar than the burner axis Ac. Furthermore, the multiple air holes 44 arranged along the circumferential direction Dcc, and the air guide member 60 extending along the circumferential direction Dcc, are also located only at a position closer to the radial outer side Drro than the burner axis Ac, similar to the anti-backflow member 65.

[0074] As described above, within the inner cylinder 32, compressed air Acom, ejected from the compressor 10, flows in from its upstream side Dcu. Each burner nozzle 31, disposed within the inner cylinder 32, ejects externally supplied fuel F along with the compressed air Acom flowing into the inner cylinder 32 towards the upstream side Dcu. Within the tail cylinder 42, the fuel F from the multiple burner nozzles 31 burns in the compressed air Acom, generating high-temperature, high-pressure combustion gas CG. This combustion gas CG flows downstream in the tail cylinder 42 towards the downstream side Dcd and into the turbine housing 28.

[0075] The gas flow path for the gas G (combustion gas CG, or air Acom and fuel F) expands sharply from the downstream end 32de of the inner cylinder, thus forming a vortex of gas G on the downstream side Dcd of the downstream end 32de of the inner cylinder. Therefore, the combustion gas CG in the tail cylinder 42 flows backward, and there is a possibility that the combustion gas CG will flow into the cylindrical gap 40 between the upstream side 43 of the tail cylinder and the downstream side 33 of the inner cylinder. If the combustion gas CG flows into this cylindrical gap 40, there is a risk of damage to the first elastic ring 50 and the second elastic ring 55, which serve as sealing components.

[0076] In this embodiment, the narrowing portion 66 of the anti-backflow component 65 narrows the gap between the upstream side 43 of the tail cylinder and the downstream side 33 of the inner cylinder, thereby suppressing the flow of the combustion gas CG into the cylindrical gap 40. Furthermore, in this embodiment, air Acom from the plurality of air holes 44 flows along the narrowing inner circumferential surface 66i of the narrowing portion 66, and this air Acom cools the narrowing portion 66, thereby suppressing thermal damage to the narrowing portion 66.

[0077] In this method, each stream of air Acom from the plurality of air holes 44 arranged along the circumferential direction Dcc flows downstream to the Dcd and then along the inner circumferential surface 66i of the reduced diameter. As it reaches the downstream end 66de of the reduced diameter, it gradually disperses along the circumferential direction Dcc. In particular, in this embodiment, the guide plate 61 of the air guide member 60 extending along the circumferential direction Dcc enables the effective dispersion of each stream of air Acom from the plurality of air holes 44 arranged along the circumferential direction Dcc. Therefore, in this embodiment, the air Acom flowing along the inner circumferential surface 66i of the reduced diameter is injected into the tailpipe 42 substantially uniformly along the circumferential direction Dcc. Thus, the air Acom injected into the tailpipe 42 functions as an appropriate air curtain against the counter-flowing combustion gas CG. Additionally, air Acom is injected into the tail cylinder 42 along with air Acom from multiple air holes 44. The air Acom flows into the cylindrical gap 40 from the gap between the upstream end 42ue of the tail cylinder and the downstream side 33 of the inner cylinder, and passes through the slit 53 of the first elastic ring 50 and the slit 58 of the second elastic ring 55 disposed in the cylindrical gap 40.

[0078] In this embodiment, as the air Acom from the plurality of air holes 44 arranged along the circumferential direction Dcc flows downstream to the Dcd, the joint 67 of the anti-backflow member 65 does not obstruct the flow of air Acom, but instead allows it to flow along the inner circumferential surface 43i of the upstream side 43 of the tail cylinder. Furthermore, in this embodiment, the air Acom from the plurality of air holes 44 can be efficiently guided to the reduced-diameter inner circumferential surface 66i by the air guide member 60. Therefore, in this embodiment, the air Acom from the plurality of air holes 44 can be efficiently guided to the reduced-diameter inner circumferential surface 66i. As a result, in this embodiment, the air Acom flow rate along the reduced-diameter inner circumferential surface 66i can be increased.

[0079] In this embodiment, after flowing along the inner circumferential surface 66i of the reduced diameter, the air Acom injected into the tail cylinder 42 has a downstream-side Dcd directional component and a radially inward-side Dcri directional component. Therefore, in this embodiment, the air Acom with the downstream-side Dcd directional component can suppress the combustion gas CG that is flowing backwards towards the upstream-side Dcu from further upstream to the upstream-side Dcu. Moreover, in this embodiment, the air Acom with the radially inward-side Dcri component can guide the combustion gas CG flowing towards the cylindrical gap 40 to the radially inward-side Dcri.

[0080] Therefore, in this method, the flow of combustion gas CG from the tail cylinder 42 into the cylindrical gap 40 between the upstream side 43 of the tail cylinder and the downstream side 33 of the inner cylinder can be suppressed with extremely high efficiency.

[0081] However, in this embodiment, as described above, the throttling section 48 in the housing opposition portion 47 of the tailstock 42 is inclined relative to the upstream side Dcu portion of the throttling start position 46 in the housing opposition portion 47. Therefore, a portion of the gas G injected from the inner cylinder 32 to the downstream side Dcd returns to the upstream side Dcu in the throttling section 48. Therefore, in the region closer to the radially outer side Drro relative to the rotor axis Ar than the burner axis Ac, the possibility of backflow of combustion gas CG in the tailstock 42 increases. Therefore, in this embodiment, in the region closer to the radially outer side Drro relative to the rotor axis Ar than the burner axis Ac, where the possibility of backflow of combustion gas CG is high, an anti-backflow component 65, a plurality of air holes 44, and an air guide component 60 are arranged.

[0082] "Variations"

[0083] In the above embodiments, the burner 30 has a first elastic ring 50 and a second elastic ring 55 as sealing components for sealing the cylindrical gap 40 between the upstream side 43 of the tail cylinder and the downstream side 33 of the inner cylinder. However, as long as the first elastic ring 50 and the second elastic ring 55 can perform the two functions mentioned above, other sealing components can be arranged in the cylindrical gap 40 instead of the first elastic ring 50 and the second elastic ring 55.

[0084] This invention is not limited to the embodiments and variations described above. Various additions, modifications, substitutions, and partial deletions can be made without departing from the conceptual idea and spirit of this invention derived from the content specified in the technical solutions and their equivalents.

[0085] "appendix"

[0086] The burner 30 in the above embodiments and variations can be understood as follows.

[0087] (1) The burner 30 in the first embodiment includes:

[0088] The inner cylinder 32 is cylindrical around the burner axis Ac; the burner nozzle 31 is disposed on the inner circumference of the inner cylinder 32, and can spray fuel F and air Acom into the downstream side Dcd in the axial direction Dc extending from the burner axis Ac; the tail cylinder 42 is cylindrical around the burner axis Ac, and allows the fuel F from the burner nozzle 31 to burn in the air Acom, and allows the combustion gas CG generated when burning fuel F to flow; and the anti-backflow member 65 extends along the circumferential direction Dcc relative to the burner axis Ac, is disposed on the inner circumference of the tail cylinder 42 and fixed to the tail cylinder 42. The inner diameter of the upstream side portion 43 of the tail cylinder, which includes the upstream side Dcu end of the tail cylinder 42, is larger than the outer diameter of the downstream side portion 33 of the inner cylinder, which includes the downstream side Dcd end of the inner cylinder 32, i.e., the downstream end 32de of the inner cylinder. The upstream side 43 of the tailpipe is positioned opposite the outer peripheral surface 33o of the downstream side 33 of the inner cylinder, spaced apart along the radial direction Dcr relative to the burner axis Ac. The upstream side 43 of the tailpipe has a plurality of air holes 44 located closer to the upstream side Dcu than the downstream end 32de of the inner cylinder. These air holes 44 are spaced apart along the circumferential direction Dcc and extend from the outer peripheral side to the inner peripheral side of the upstream side 43 of the tailpipe. Each air hole 44 has an inlet 44i opening on the outer peripheral surface 43o of the upstream side 43 of the tailpipe; and an outlet 44o opening on the inner peripheral surface 43i of the upstream side 43 of the tailpipe. The anti-backflow component 65 includes: a reduced diameter portion 66, the inner diameter of which gradually decreases towards the downstream side Dcd; and a connecting portion 67, which connects to the upstream side Dcu end of the reduced diameter portion 66 and engages with the upstream side portion 43 of the tail cylinder at a position closer to the downstream side Dcd than the outlet 44o of each of the plurality of air holes 44. The downstream end 66de of the reduced diameter portion 66, which is closest to the downstream side Dcd on the inner circumferential surface 66i of the reduced diameter portion 66, is located closer to the downstream side Dcd than the downstream end 32de of the inner cylinder.

[0089] The gas flow path for the gas G (combustion gas CG, or air Acom and fuel F) expands sharply from the downstream end 32de of the inner cylinder, thus forming a vortex of gas G on the downstream side Dcd of the downstream end 32de of the inner cylinder. Therefore, the combustion gas CG in the tail cylinder 42 experiences backflow, and there is a possibility that the combustion gas CG will flow into the cylindrical gap 40 between the upstream side 43 of the tail cylinder and the downstream side 33 of the inner cylinder. Assuming a sealing component is installed in this cylindrical gap 40, if the combustion gas CG flows into this cylindrical gap 40, the sealing component is at risk of damage.

[0090] In this method, the narrowing portion 66 of the anti-backflow component 65 narrows the gap between the upstream side 43 of the tail cylinder and the downstream side 33 of the inner cylinder, thereby suppressing the flow of the combustion gas CG into the cylindrical gap 40. Furthermore, in this method, air Acom from the plurality of air holes 44 flows along the narrowing inner circumferential surface 66i of the narrowing portion 66, and this air Acom cools the narrowing portion 66, thereby suppressing thermal damage to the narrowing portion 66.

[0091] In this configuration, each stream of air Acom from the plurality of air holes 44 arranged along the circumferential direction Dcc flows downstream to the Dcd and then along the inner circumferential surface 66i of the constricted diameter. As it reaches the downstream end 66de of the constricted diameter, it gradually disperses along the circumferential direction Dcc. Therefore, in this configuration, the air Acom flowing along the inner circumferential surface 66i of the constricted diameter is injected into the tailpipe 42 approximately uniformly along the circumferential direction Dcc. Thus, the air Acom injected into the tailpipe 42 functions as an appropriate air curtain against the counter-flowing combustion gas CG.

[0092] In this method, after flowing along the inner circumferential surface 66i of the reduced diameter, the air Acom injected into the tailpipe 42 has a downstream-side Dcd directional component and a radially inward-side Dcri directional component. Therefore, in this method, the air Acom with the downstream-side Dcd directional component can suppress the combustion gas CG flowing towards the upstream-side Dcu from further flowing towards the upstream-side Dcu. Moreover, in this method, the air Acom with the radially inward-side Dcri component can guide the combustion gas CG flowing towards the cylindrical gap 40 to the radially inward-side Dcri.

[0093] Therefore, in this method, the flow of combustion gas CG from the tail cylinder 42 into the cylindrical gap 40 between the upstream side 43 of the tail cylinder and the downstream side 33 of the inner cylinder can be suppressed with extremely high efficiency.

[0094] (2) Regarding the burner 30 in the second method,

[0095] In the burner 30 of the first embodiment, the reduced-diameter inner circumferential surface 66i is inclined at an angle of 30° or more and 60° or less relative to the outer circumferential surface 33o of the downstream side portion 33 of the inner cylinder.

[0096] (3) Regarding the burner 30 in the third method,

[0097] In the burner 30 of either the first or second embodiment, the downstream end 66de of the reduced diameter is located closer to the radially inner side Dcri relative to the burner axis Ac than the following location: the location is half the distance g between the outer peripheral surface 33o of the downstream side 33 of the inner cylinder and the inner peripheral surface 43i of the upstream side 43 of the tail cylinder, from the inner peripheral surface 43i of the tail cylinder to the axial direction Dc of the downstream end 32de of the inner cylinder.

[0098] In this method, the narrowing portion 66 of the anti-backflow component 65 narrows the gap between the upstream side 43 of the tail cylinder and the downstream side 33 of the inner cylinder, thereby suppressing the flow of the combustion gas CG into the cylindrical gap 40.

[0099] (4) Regarding the burner 30 in the fourth method,

[0100] In any of the first to the third methods of the burner 30, the downstream end 66de of the reduced diameter is located closer to the radially outer side Dcro relative to the burner axis Ac than the downstream end 32de of the inner cylinder.

[0101] When the burner 30 starts, a thermal expansion difference Dc in the axial direction is generated between the inner cylinder 32 and the tail cylinder 42. In this configuration, since the downstream end 66de of the reduced diameter is closer to the radially outer side Dcro than the downstream end 32de of the inner cylinder, even if a thermal expansion difference Dc in the axial direction is generated between the inner cylinder 32 and the tail cylinder 42, it is possible to prevent the anti-backflow component 65 fixed on the tail cylinder 42 from contacting the inner cylinder 32 and being damaged.

[0102] (5) Regarding the burner 30 in the fifth method,

[0103] In any of the first to fourth embodiments of the burner 30, an air guide member 60 is provided, which can guide the air Acom that flows from the plurality of air holes 44 into the space between the upstream side 43 of the tail cylinder and the downstream side 33 of the inner cylinder along the inner circumferential surface 43i of the upstream side 43 of the tail cylinder to the downstream side Dcd.

[0104] In this method, air Acom from multiple air holes 44 can be efficiently guided to the narrowed inner circumferential surface 66i. As a result, the air Acom flow rate along the narrowed inner circumferential surface 66i increases.

[0105] Therefore, in this method, it is possible to effectively suppress the inflow of combustion gas CG into the cylindrical gap 40 and suppress thermal damage to the narrowed section 66.

[0106] (6) Regarding the burner 30 in the sixth method,

[0107] In the burner 30 of the fifth embodiment, the air guiding member 60 includes: a guide plate 61, configured to be positioned opposite, at a distance in the radial direction Dcr, to the region where the outlets 44o of the plurality of air holes 44 are formed, in the inner circumferential surface 43i of the upstream side portion 43 of the tailstock, and extending along the circumferential direction Dcc; and a sealing plate 62, positioned closer to the upstream side Dcu than the outlets 44o of the plurality of air holes 44, for sealing the gap between the inner circumferential surface 43i of the upstream side portion 43 of the tailstock and the guide plate 61. The guide plate 61 extends to a position closer to the downstream side Dcd than the outlets 44o of the plurality of air holes 44 and closer to the upstream side Dcu than the reduced diameter portion 66 of the anti-backflow member 65.

[0108] In this configuration, the guide plate 61 extending along the circumferential direction Dcc enables the individual air streams Acom from the plurality of air holes 44 arranged along the circumferential direction Dcc to be effectively dispersed along the circumferential direction Dcc. Moreover, in this configuration, the air Acom from the plurality of air holes 44 can be efficiently guided to the narrowed inner circumferential surface 66i.

[0109] (7) Regarding the burner 30 in the seventh method,

[0110] In the burner 30 of the sixth embodiment, the air guide member 60 has spaced retaining protrusions 63 that protrude from the guide plate 61 toward the radially outer side Dcro relative to the burner axis Ac at a position closer to the downstream side Dcd than the respective outlets 44o of the plurality of air holes 44, and are spaced apart on the circumferential Dcc, and contact the inner circumferential surface 43i of the upstream side 43 of the tailstock.

[0111] (8) Regarding the burner 30 in the eighth method,

[0112] In the burner 30 of any of the first to seventh embodiments, the engagement 67 of the anti-backflow component 65 has a thickness in the radial direction Dcr. The upstream side 43 of the tailstock has a recess 45 that is recessed from the inner circumferential surface 43i of the upstream side 43 of the tailstock towards the radially outer direction Dcro relative to the burner axis Ac, and extends along the circumferential direction Dcc, at a position closer to the downstream side Dcd than the respective outlets 44o of the plurality of air holes 44. The depth of the recess 45 corresponds to the thickness of the engagement 67. The engagement 67 enters the recess 45 of the upstream side 43 of the tailstock and engages with the upstream side 43 of the tailstock.

[0113] In this configuration, as air Acom flows downstream from the plurality of air holes 44 arranged along the circumferential direction Dcc to the downstream side Dcd, the joint 67 of the anti-backflow component 65 does not obstruct the flow of air Acom, but instead allows it to flow along the inner circumferential surface 43i of the upstream side 43 of the tailstock. Therefore, in this configuration, air Acom from the plurality of air holes 44 can be efficiently guided to the reduced-diameter inner circumferential surface 66i, and the air Acom flow rate along the reduced-diameter inner circumferential surface 66i can be increased.

[0114] The gas turbines in the above-described embodiments and variations can be understood as follows.

[0115] (9) The gas turbine in the ninth method has the following features:

[0116] The combustion chamber 30 is provided in any of the first to eighth embodiments; a compressor 10 is provided, capable of generating compressed air Acom by compressing air Acom; a turbine 20 is provided, capable of being driven by combustion gas CG from the combustion chamber 30; and an intermediate housing 6 is provided, allowing compressed air Acom from the compressor 10 to flow in. The compressor 10 includes: a compressor rotor 11, capable of rotating about a rotor axis Ar; and a compressor housing 18 for covering the compressor rotor 11. The turbine 20 includes: a turbine rotor 21, capable of rotating about the rotor axis Ar; and a turbine housing 28 for covering the turbine rotor 21. The compressor rotor 11 and the turbine rotor 21 are interconnected to form a gas turbine rotor 1. The intermediate housing 6 is located between the compressor housing 18 and the turbine housing 28. The compressor housing 18, the intermediate housing 6, and the turbine housing 28 are interconnected to form a gas turbine housing 8. The burner 30 is mounted on the intermediate housing 6 so that compressed air Acom inside the intermediate housing 6 can flow into the burner 30.

[0117] (10) Regarding the gas turbine in the tenth method,

[0118] In the gas turbine of the ninth embodiment, the plurality of air holes 44 and the anti-backflow component 65 of the upstream side of the tailstock 43 are located closer to the radially outer Drro position relative to the rotor axis Ar than the burner axis Ac.

[0119] In the region closer to the radially outer side Drro relative to the rotor axis Ar than the burner axis Ac, the flow of combustion gas CG from the tail cylinder 42 into the cylindrical gap 40 between the upstream side 43 of the tail cylinder and the downstream side 33 of the inner cylinder can be suppressed with extremely high efficiency.

[0120] Industrial availability

[0121] According to one aspect of the present invention, it is possible to efficiently suppress the flow of combustion gases into the gap between the tail cylinder and the inner cylinder.

[0122] Symbol Explanation

[0123] 1-Gas turbine rotor, 6-Intermediate casing, 8-Gas turbine casing, 10-Compressor, 11-Compressor rotor, 12-Rotor shaft, 13-Moving blade cascade, 15-Stationary blade cascade, 18-Compressor casing, 20-Turbine, 21-Turbine rotor, 22-Rotor shaft, 23-Moving blade cascade, 25-Stationary blade cascade, 28-Turbine casing, 30-Burner, 31-Burner nozzle, 32-Inner cylinder, 32de-Downstream end of inner cylinder, 33-Downstream side of inner cylinder, 33o- 40 - Outer circumferential surface, 41 - Cylindrical gap, 42 - Enclosed area, 42 - Tail tube, 42ue - Upstream end of tail tube, 43 - Upstream side of tail tube, 43i - Inner circumferential surface, 43o - Outer circumferential surface, 44 - Air hole, 44i - Inlet, 44o - Outlet, 45 - Recess, 46 - Throttling start position, 47 - Housing opposite part, 48 - Throttling part, 49 - Rotor opposite part, 50 - First elastic ring, 51 - Fixing part, 52 - Spring part, 53 - Slit, 54a - First connection 54b - Second contact part, 55 - Second elastic ring, 56 - Fixing part, 57 - Spring part, 58 - Slit, 59 - Contact part, 60 - Air guide component, 61 - Guide plate, 62 - Sealing plate, 63 - Spacer retaining protrusion, 65 - Anti-backflow component, 66 - Reduced diameter part, 66i - Reduced diameter inner circumferential surface, 66de - Reduced diameter downstream end, 67 - Joint, A - Air, Acom - Compressed air (or simply air), F - Fuel, G - Combustion gas Or air and fuel, CG - combustion gas, g - gap, α - angle, Ac - burner axis, Dc - axis direction, Dcu - upstream side, Dcd - downstream side, Dcc - circumferential, Dcr - radial, Dcri - radial inner side, Dcro - radial outer side, Ar - rotor axis, Dr - rotor axis direction, Dru - upstream side of rotor axis, Drd - downstream side of rotor axis, Drrr - radial, Drri - radial inner side, Drro - radial outer side.

Claims

1. A burner comprising: The inner cylinder is cylindrical, surrounding the burner axis. The burner nozzle is disposed on the inner circumferential side of the inner cylinder, and is capable of spraying fuel and air to the downstream side in the upstream and downstream directions of the axial direction extending from the burner axis. The tail tube is cylindrical around the axis of the burner and allows the fuel from the burner nozzle to burn in the air, while also allowing the combustion gases produced during fuel combustion to flow through. as well as An anti-backflow component extends circumferentially relative to the burner axis, is disposed on the inner circumferential side of the tailstock, and is fixed to the tailstock. The inner diameter of the upstream end of the tail cylinder, including the upstream end of the tail cylinder, is larger than the outer diameter of the downstream end of the inner cylinder, i.e., the downstream end of the inner cylinder. The upstream side of the tail cylinder is positioned opposite the outer peripheral surface of the downstream side of the inner cylinder, spaced apart radially with respect to the burner axis. The upstream side of the tail cylinder has a plurality of air holes located closer to the upstream side than the downstream end of the inner cylinder. The plurality of air holes are arranged at intervals in the circumferential direction and extend from the outer circumferential side to the inner circumferential side of the upstream side of the tail cylinder. The plurality of air holes have: an inlet, opening on the outer peripheral surface of the upstream side of the tailstock; and an outlet, opening on the inner peripheral surface of the upstream side of the tailstock. The anti-backflow component includes: a reduced diameter portion, the inner diameter of which gradually decreases towards the downstream side; and a connecting portion, which connects to the upstream end of the reduced diameter portion and engages with the upstream side of the tailstock at a position closer to the downstream side than the outlets of each of the plurality of air holes. The position of the inner circumferential surface of the reduced diameter section, that is, the downstream end of the reduced diameter section closest to the downstream side, is located closer to the downstream side than the downstream end of the inner cylinder.

2. The burner according to claim 1, wherein, The inner circumferential surface of the reduced diameter is inclined at an angle of more than 30° and less than 60° relative to the outer circumferential surface of the downstream side of the inner cylinder.

3. The burner according to claim 1, wherein, The downstream end of the reduced diameter is located closer to the radially inner side relative to the burner axis than the following location: the location being half the distance between the outer circumferential surface of the downstream side of the inner cylinder and the inner circumferential surface of the upstream side of the tail cylinder at a position in the axial direction from the inner circumferential surface of the upstream side of the tail cylinder to the axial surface of the downstream end of the inner cylinder.

4. The burner according to claim 1, wherein, The downstream end of the reduced diameter is located closer to the radial outer side relative to the burner axis than the downstream end of the inner cylinder.

5. The burner according to claim 1, comprising: An air guiding component is capable of guiding air flowing from the plurality of air holes between the upstream side of the tail cylinder and the downstream side of the inner cylinder along the inner circumferential surface of the upstream side of the tail cylinder to the downstream side.

6. The burner according to claim 5, wherein, The air guiding component has a guide plate that extends circumferentially in a manner that is radially spaced apart from and opposite to the regions where the outlets of the plurality of air holes are formed in the inner circumferential surface of the upstream side of the tail cylinder; And a sealing plate, positioned closer to the upstream side than the respective outlets of the plurality of air holes, for sealing the gap between the inner circumferential surface of the upstream side of the tailstock and the guide plate. The guide plate extends to a position closer to the downstream side than the outlet of each of the plurality of air holes and closer to the upstream side than the reduced diameter portion of the anti-backflow component.

7. The burner according to claim 6, wherein, The air guide component has spaced retaining protrusions that protrude radially outward from the guide plate relative to the burner axis at a position closer to the upstream side than the respective outlets of the plurality of air holes, and are spaced apart in the circumferential direction and contact the inner circumferential surface of the upstream side of the tailstock.

8. The burner according to claim 1, wherein, The joint of the anti-backflow component has a radial thickness relative to the burner axis. The upstream side of the tailstock has a recess that is recessed radially outward relative to the burner axis and extends circumferentially, at a position closer to the downstream side than the respective outlets of the plurality of air holes. The depth of the recess corresponds to the thickness of the joint. The joint enters the recess on the upstream side of the tail cylinder and engages with the upstream side of the tail cylinder.

9. A gas turbine, comprising: The burner according to any one of claims 1 to 8; An air compressor is capable of generating compressed air by compressing air. A turbine, capable of being driven by combustion gases from the burner; and The intermediate casing allows compressed air from the compressor to flow in. The compressor includes: a compressor rotor capable of rotating about a rotor axis; and a compressor housing for covering the compressor rotor. The turbine has: a turbine rotor capable of rotating about its axis; and a turbine housing for covering the turbine rotor. The compressor rotor and the turbine rotor are interconnected to form a gas turbine rotor. The intermediate housing is located between the compressor housing and the turbine housing. The compressor housing, the intermediate housing, and the turbine housing are interconnected to form the gas turbine housing. The burner is mounted on the intermediate housing so that compressed air inside the intermediate housing can flow into the burner.

10. The gas turbine according to claim 9, wherein, The plurality of air holes and the anti-backflow component on the upstream side of the tail tube are all located closer to the radial outer side relative to the rotor axis than the burner axis.

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