Rear inner cap plate removal method and tool for combustor with micromixer tube

Abstract

To provide an improved method and tool for safely removing a rear inner cap end plate from a micromixer head end.SOLUTION: A combustor 25 includes a rear plate 78 with a central passage and a plurality of tubes extending through the rear plate. A rear plate removal tool 100 includes: a central screw; a lower housing attached to the central screw, the lower housing including a plurality of spring loaded lower housing feet; and an upper housing attached to the center screw, the upper housing including a plurality of spring loaded upper housing feet. The rear plate removal tool is inserted through the central passage of the rear plate such that rotation of the upper housing advances the spring loaded upper housing feet against the rear plate until the spring loaded upper housing feet push the rear plate off of the tubes.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE This application and the resulting patent relate generally to gas turbine engines, and more particularly to an improved method and tool for safely removing an aft inner cap plate from a combustor micro-mixer head end during repair or replacement. [Background technology]

[0002] A gas turbine engine conventionally includes a compressor that compresses ambient air and multiple combustors that mix a flow of air with a flow of fuel to generate hot combustion gases. A turbine receives the flow of hot combustion gases and extracts energy therefrom to power the compressor and to provide output power to an external load, such as a generator. The combustors may be arranged in an annular configuration between the compressor and the turbine.

[0003] The combustor may include one or more bundle tube fuel injectors extending downstream from the end cover. The bundle tube fuel injector typically includes a plurality of premix or micro-mixer tubes. The micro-mixer tubes typically extend parallel to one another within the bundle tube fuel injector. An outer shroud extends circumferentially around the micro-mixer tubes and an aft plate extends radially and circumferentially across a downstream end thereof adjacent a combustion chamber or zone defined within the combustor. A tube tip portion of each micro-mixer tube extends through the aft plate such that an outlet of each tube is located downstream from a hot side surface of the aft plate, thereby providing fluid communication to the combustion chamber or zone.

[0004] Each micro-mixer tube extends generally axially through a fuel plenum and a cooling air plenum. Compressed air is supplied to each micro-mixer tube at an inlet upstream from the fuel plenum. Fuel is injected into each micro-mixer tube through one or more fuel ports located within the micro-mixer tube. The fuel and compressed air are mixed in the micro-mixer tube and exit each tube into a combustion chamber or zone for combustion.

[0005] During combustor operation, the downstream or terminal end of each micro-mixer tube is exposed to extremely high temperatures due to its proximity to the combustion chamber and / or combustion flame. Similarly, the rear plate through which the micro-mixer tubes extend may also deform or dish under harsh conditions. Over time, various factors including thermal stresses, mechanical fatigue, combustion dynamics or vibrations may adversely affect the operating condition of the bundle tube fuel injector, thus necessitating periodic inspection and possibly repair or refurbishment of the part. Specifically, dishing and close fit of the rear plate may bind the micro-mixer tubes that penetrate the rear plate. However, moving it to the right to remove the rear plate may damage the fuel injector. Summary of the Invention

[0006] Accordingly, this application and the resultant patent provide an aft plate removal tool for servicing a combustor. The combustor includes an aft plate having a central passageway and a plurality of tubes extending through the aft plate. The aft plate removal tool includes a central screw, a lower housing attached to the central screw, an upper housing attached to the central screw, an upper housing attached to the central screw, and a plurality of spring loaded upper housing legs attached to the upper housing. The aft plate removal tool is inserted through the central passageway of the aft plate and rotation of the upper housing advances the spring loaded upper housing legs against the aft plate until the spring loaded upper housing legs push the aft plate off the tubes.

[0007] The present application and the resultant patent further provides a method of removing an aft plate from a plurality of tubes of a combustor that may include inserting an aft plate removal tool through the aft plate, releasing a plurality of legs of the aft plate removal tool, rotating an upper housing of the aft plate removal tool to cause the plurality of legs to contact the aft plate, further rotating the upper housing to deform the aft plate, and further rotating the upper housing to push the aft plate away from the tubes.

[0008] These and other features and improvements of the present application and the resulting patent will become apparent to those of ordinary skill in the art upon review of the following detailed description, when considered in conjunction with the several drawing figures and the appended claims. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic diagram of a gas turbine engine including a compressor, a combustor, a turbine, and an external load. [Diagram 2] FIG. 2 is a schematic diagram of a combustor that can be used in the gas turbine engine of FIG. 1. [Diagram 3] 3 is a perspective view of a fuel nozzle assembly of the combustor of FIG. 2. [Figure 4] FIG. 3 is a schematic diagram of a fuel injector that can be used with the combustor of FIG. 2. [Diagram 5] 3 is a perspective view of an alternative embodiment of a fuel nozzle assembly that may be used with the combustor of FIG. 2. [Figure 6] FIG. 1 is a perspective view of an example of a back plate removal tool as may be described herein. [Figure 7] FIG. 7 is a partial cross-sectional view of the combustor of FIG. 6 with the aft plate removal tool attached. [Figure 8] FIG. 2 is a partial perspective view of a combustor end plate with an aft plate removal tool attached; [Figure 9] FIG. 13 is a top view of an alternative embodiment of a back plate removal tool as may be described herein. [Figure 10] FIG. 10 is a cross-sectional view of the rear plate removal tool of FIG. [Figure 11] 10 is a further cross-sectional view of the rear plate removal tool of FIG. 9. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Referring now to the drawings, where like numerals indicate like elements throughout the several views, FIG. 1 is a schematic diagram of a gas turbine engine 10 as may be described herein. The gas turbine engine 10 may include a compressor 15. The compressor 15 compresses an incoming airflow 20. The compressor 15 delivers the compressed airflow 20 to a number of combustor cans 25. The combustor cans 25 mix the compressed airflow 20 with a pressurized fuel flow 30 and ignite the mixture to generate a hot combustion gas flow 35. Although only a single combustor can 25 is shown, the gas turbine engine 10 may include any number of combustor cans 25 arranged, such as in a circumferential array. Alternatively, the combustor 25 may be an annular combustor. The flow of combustion gases 35 is in turn delivered to a turbine 40. The flow of combustion gases 35 drives the turbine 40 to generate mechanical work. The mechanical work generated in the turbine 40 drives the compressor 15 via a rotor shaft 45. The turbine 40 and rotor shaft 45 may also drive an external load 50, such as an electrical generator.

[0011] The gas turbine engine 10 may use natural gas, various types of synthetic gas, liquid fuels, and / or other types of fuels and mixtures thereof. The gas turbine engine 10 may be any of several different gas turbine engines offered by General Electric Company of Schenectady, New York, including, but not limited to, a 7 Series or 9 Series heavy duty gas turbine engine. The gas turbine engine 10 may be part of a simple cycle power generation system or a combined cycle power generation system or other types of power generation systems. The gas turbine engine 10 may have different configurations and may use other types of components. Other types of gas turbine engines may also be used herein. Multiple gas turbine engines, other types of turbines, and other types of power generation devices may also be used herein.

[0012] 2 is a partial cross-sectional view of the combustor 25. The combustor 25 may incorporate a number of fuel injectors 52 therein. The fuel nozzles 52 may be coupled to a fuel nozzle assembly 53. In this example, the fuel injectors 52 may be bundle tube fuel injectors or the like. The combustor 25 is at least partially surrounded by an outer casing 54. The outer casing 54 forms a high pressure plenum 56 around the combustor 25. The high pressure plenum 56 may be in fluid communication with the compressor 15 or other source for supplying the flow of air 20 to the combustor 25. An end cover 58 is coupled to the outer casing 54. The end cover 58 may be in fluid communication with the flow of fuel 30.

[0013] The fuel injectors 52 extend downstream from an end cover 58. The fuel injectors 52 may be in fluid communication with the end cover 58 to receive the flow of fuel 30. For example, a fluid conduit 60 may provide fluid communication between the end cover 58 and the fuel injectors 52. One end of an annular liner 62, such as a combustion liner and / or transition duct, surrounds a downstream end 64 of the fuel injectors 52 to at least partially define a combustion chamber 66. The liner 62 defines a hot gas path 68 for directing the combustion gases 35 from the combustion chamber 66.

[0014] During operation, the air 20 flow is directed towards the end cover 58 where it reverses direction to flow through one or more fuel injectors 52. A fuel 30 flow is delivered to the fuel injectors 52 and the fuel 30 flow and air 20 flow are premixed or combined within the fuel injectors 52 before being injected into the combustion chamber 66 for combustion.

[0015] FIG 3 is a perspective view of the fuel injector assembly 53, and FIG 4 is a cross-sectional view of one example of the fuel injector 52 described above. The fuel injector 52 generally includes a fuel distribution module 70 in fluid communication with the fluid conduit 60. The fuel distribution module 70 includes an upstream plate 72 axially spaced from a downstream plate 74. A fuel plenum 76 may be defined between the upstream and downstream plates 72, 74. The fluid conduit 60 provides a flow of fuel 30 to the fuel plenum 76.

[0016] An aft plate 78 is disposed at the downstream or aft end of the fuel injector 52. The aft plate 78 extends radially outwardly and circumferentially across the aft end with respect to an axial centerline. The aft plate 78 defines, at least in part, a plurality of tube tip passages 82 extending generally axially therethrough. An impingement plate 84 is disposed upstream of the aft plate 78. The impingement plate 84 may be welded, brazed, or otherwise coupled to the aft plate 78. The aft plate 78 and / or impingement plate 84 may define, at least in part, a central passage 86 extending generally axially therethrough. A fluid cartridge insert 88 may be coupled to the aft plate 78 at the central passage 86. The aft plate 78 , impingement plate 84 , and related components herein may be described as an inner cap assembly 94 .

[0017] The fuel injector 52 includes a micro-mixer tube bundle 90. The micro-mixer tube bundle 90 includes a plurality of micro-mixer (or pre-mixer) tubes 92 that extend generally parallel to one another along or parallel to an axial centerline of the fuel injector 52. The micro-mixer tubes 92 extend downstream from the fuel plenum 76 toward the aft plate 78 and / or the combustion chamber 66. A portion of the micro-mixer tubes 92 extend through the aft plate 78. Each micro-mixer tube 92 is generally aligned with a corresponding tube tip passage 82. The micro-mixer tubes 92 may be arranged in multiple rows, or the like. Similarly, FIG. 5 illustrates an alternative embodiment of the fuel nozzle assembly 53 with the addition of a central liquid fuel nozzle 96.

[0018] FIG. 6 illustrates an aft plate removal tool 100 as may be described herein. In this example, an inner aft plate removal tool 105 is shown. As the name suggests, the inner aft plate removal tool 105 is used in the combustor 25 to remove the aft plate 78 and the inner cap assembly 94. Specifically, the inner aft plate removal tool 105 can reshape and remove the aft plate 78 without damaging the micro-mixer tubes 92. The inner aft plate removal tool 105 can be used with the fuel nozzle assembly 53 of FIG.

[0019] The inner aft plate removal tool 105 may include a base plate 110 having a base plate opening 120, a threaded insert 130 disposed within the base plate opening 120, and a threaded rod 140 extending through the threaded insert 130. The threaded rod 140 may have a replaceable tip 150 at its rear end. The replaceable tip 150 may be made of Delrin (polyoxymethylene) or a similar material to protect against wear due to frictional contact with the aft plate 78. The threaded rod 140 may also include an outer sleeve 160 to protect the adjacent micro-mixer tubes 92. The threaded rod 140 may have any convenient length and other dimensions. The base plate 110 may have a number of mounting openings 170 therein. The inner aft plate removal tool 105 may be attached to the end cover 58 of the combustor 25 using a number of mounting bolts 180 or the like. Other components and configurations may be used herein.

[0020] 7 and 8 illustrate the use of the inner aft plate removal tool 105. The inner aft plate removal tool 105 may be inserted into the central passage 86 of the combustor 25. The inner aft plate removal tool 105 may be advanced therethrough until the replaceable tip 150 contacts the aft plate 78. The base plate 110 may be attached to the end cover 48 by installing the mounting bolts 180. Once securely in place, the threaded rod 140 may be rotated and advanced. Specifically, the threaded rod 140 is rotated within the threaded insert 130 of the base plate 110.

[0021] As the threaded rod 140 contacts and advances against the aft plate 78, the threaded rod 140 flattens the deformation of the aft plate 78. As the aft plate 78 flattens, the aft plate 78 and the inner cap assembly 94 begin to separate from the micro-mixer tube 92. The threaded rod 140 continues to advance until the aft plate 78 and the inner cap assembly 94 are fully pushed out of the micro-mixer tube 92. The advancement of the threaded rod 140 allows the aft plate 78 and the inner cap assembly 94 to slide freely out of the micro-mixer tube 92. The threaded rod 140 can be rotated in the opposite direction to remove the inner aft plate removal tool 105 from the end cover 58. The inner aft plate removal tool 105 may be withdrawn from the combustor 25.

[0022] 9-11 show a further embodiment of the aft plate removal tool 100. In this example, an outer aft plate removal tool 200 is shown. As the name suggests, the outer aft plate removal tool 200 is used to remove the aft plate 78 and inner cap assembly 94 from outside the combustor 25. The outer aft plate removal tool 200 can be used with the fuel nozzle assembly 95 of FIG. 5 once the central liquid fuel nozzle 96 is removed.

[0023] The outer rear plate removal tool 200 may include a central screw 210. A lower housing 220 and an upper housing 230 may be attached to the central screw 210. The central screw 210 may be fixed within the lower housing 220. The lower housing 220 may also have a pair of slide rods 240 fixed therein. Each slide rod 240 may have a slide rod bearing 245 thereon. The upper housing 230 may be rotatably attached to the central screw 210. The upper housing 230 may also have a complementary slide rod bore 250 formed therein. The upper housing 230 may be rotatable relative to the lower housing 220 along the central screw 210 and the slide rods 240.

[0024] The lower housing 220 may have a pair of lower feet 260 attached thereto. Each of the pair of lower feet 260 may be attached to the lower housing 220 by a lower pin 270. Each of the pair of lower feet 260 may be spring loaded via a lower spring 280. The lower legs 260 may be rotatable via an upper spring 280. Similarly, the upper housing 230 may have a pair of upper feet 290 attached thereto. Each of the pair of upper legs 290 may be attached to the upper housing 230 by an upper pin 300. Each of the pair of upper legs 290 may be spring loaded via an upper spring 310. The upper legs 290 may be rotatable via the upper spring 310. Each of the upper legs 290 may have an upper leg pad 320 thereon. The upper leg pad 320 may be made of Delrin (Polyoxymethylene) or similar material to protect against frictional contact with the rear plate 78. The lower leg 260 and upper leg 290 may be recessed within the housings 220, 230 via set screws 330 or the like. Other components and configurations may be used herein.

[0025] In use, the lower leg 260 and the upper leg 290 can be retracted via the set screw 330. The outer rear plate removal tool 200 can be inserted into the central passage 86 of the rear plate 78 and the inner cap assembly 94. Once clear of the rear plate 78, the lower leg 260 and the upper leg 290 can be extended. The lower leg 260 can be positioned with respect to the downstream plate 74 and the upper leg 290 can be positioned below the rear plate 78. The upper housing 230 can be rotated and moved upward relative to the rear plate 78. As the upper housing 230 advances against the rear plate 78, the upper leg 290 can flatten any deformations in the rear plate 78. As the rear plate 78 flattens, the rear plate 78 and the inner cap assembly 94 begin to separate from the micro-mixer tube 92. The upper housing 230 and upper legs 290 continue to advance until the back plate 78 and inner cap assembly 94 are pushed completely out of the micromixer tube 92 .

[0026] This advancement of the upper housing 230 allows the back plate 78 and inner cap assembly 94 to slide freely out of the micro-mixer tube 92. The back plate 78 and back plate outer removal tool 200 may then be withdrawn from the combustor 25. In this manner, the outer back plate removal tool 200 can safely remove the back plate 78 and inner cap assembly 94 from the micro-mixer tube 92 in a fast and efficient manner.

[0027] It should be apparent that the foregoing relates only to specific embodiments of this application and the resulting patent. Multiple changes and modifications may be made herein by those skilled in the art without departing from the general spirit and scope of the invention as defined by the following claims and their equivalents.

[0028] Further aspects of the invention are provided by the subject matter of the following clauses. [Embodiment 1] An aft plate removal tool for servicing a combustor, the combustor comprising an aft plate with a central passage and a plurality of tubes extending through the aft plate, the aft plate removal tool including a central screw, a lower housing attached to the central screw, the lower housing comprising a plurality of spring loaded lower housing feet, and an upper housing attached to the center screw. The upper housing comprises a plurality of spring loaded upper housing feet. The aft plate removal tool is inserted through the central passage of the aft plate.Rotation of the upper housing advances the plurality of spring loaded upper housing feet against the aft plate until the plurality of spring loaded upper housing feet push the aft plate off of the plurality of tubes. [Embodiment 2] A rear plate removal tool as described in any of the preceding embodiments, wherein the central screw is fixed within the lower housing. [Embodiment 3] A rear plate removal tool as described in any of the preceding embodiments, wherein the upper housing rotates about the central screw. [Embodiment 4] A rear plate removal tool as in any preceding clause, wherein the plurality of spring loaded upper housing feet comprises pads thereon. [Embodiment 5] A rear plate removal tool as described in any of the preceding embodiments, wherein the pads comprise a polyoxymethylene material. [Embodiment 6] A rear plate removal tool as described in any of the preceding embodiments, wherein the lower housing comprises a slide rod fixed therein and the upper housing rotates about the slide rod. [Embodiment 7] A rear plate removal tool as described in any of the preceding embodiments, wherein the slide rod comprises a bearing thereon. [Embodiment 8] A rear plate removal tool as described in any of the preceding embodiments, wherein the plurality of spring loaded lower housing feet comprises a pair of spring loaded lower housing feet and the plurality of spring loaded upper housing legs comprises a pair of spring loaded upper housing feet. [Embodiment 9] A method of removing an aft plate from a plurality of tubes of a combustor, the method including the steps of inserting an aft plate removal tool through the aft plate, releasing a plurality of feet of the aft plate removal tool, rotating an upper housing of the aft plate removal tool to advance a number of the plurality of feet into contact with the aft plate, further rotating the upper housing to deform the aft plate, and further rotating the upper housing to push the aft plate off of the plurality of tubes. [Embodiment 10] A method as described in any of the preceding embodiments, wherein the aft plate removal tool is inserted through a central passage of the aft plate. [Embodiment 11] A method as described in any of the preceding embodiments, wherein a lower housing and the upper housing are attached to a central screw. [Embodiment 12] A method as described in any of the preceding embodiments, wherein the central screw is fixed within the lower housing. [Embodiment 13] The method of any of the preceding embodiments, wherein the upper housing rotates about the central screw. [Embodiment 14] The method described in any of the preceding clauses, wherein the plurality of feet comprises a plurality of spring loaded feet. [Embodiment 15] A method as described in any of the preceding embodiments, wherein the plurality of feet comprises a pair of upper housing feet and a pair of lower housing feet. [Embodiment 16] A method as described in any of the preceding embodiments, wherein the pair of upper housing feet comprises pads thereon. [Embodiment 17] The method of any of the preceding embodiments, wherein the pads comprise a polyoxymethylene material. [Embodiment 18] The method of any of the preceding embodiments, wherein the lower housing comprises a slide rod fixed therein and the upper housing rotates about the slide rod. [Embodiment 19] A method as described in any of the preceding embodiments, wherein the slide rod comprises a bearing thereon. [Explanation of symbols]

[0029] 10:Gas turbine engine 15:Compressor 20:Air flow / Air stream 25:Combustor / Combustor can 30:Fuel flow / Fuel stream 35:Combustion gas / Combustion gas stream 40:Turbine 45:Rotor shaft 50:External load 52:Fuel injector / Fuel nozzle / Bundle tube fuel injector 53:Fuel nozzle assembly 54:Outer casing 56:Plenum 58;End cover 60:Fluid conduit 62:Annular liner 64:Downstream end 66:Combustion chamber 68:Hot gas path 70:Fuel distribution module 72:Upstream plate 74:Downstream plate 76:Fuel plenum 78:Aft plate 82:Tube tip passage 84:Impingement plate 86:Center passage 88:Fluid cartridge insert 90:Micro mixer tube bundle 92:Micro mixer tube 94:Inner cap assembly 95:Fuel nozzle assembly 96: Center liquid fuel nozzle 100: Rear plate removal tool 105: Inner rear plate removal tool 110: Base plate 120: Base plate opening 130: Threaded insert 140: Threaded rod 150: Replaceable tip 160: Outer sleeve 170: Mounting opening 180: Mounting bolt 200: Outer rear plate removal tool 210: Center screw 220: Lower housing 230: Upper housing 240: Slide rod 245: Slide rod bearing 250: Slide rod bore 260: Lower leg 270: Lower pin 280: Lower spring 290: Upper leg 300: Upper pin 310: Upper spring 320: Upper leg pad 330: Set screw

Claims

1. 1. An aft plate removal tool (100) for servicing a combustor (25), the combustor (25) including an aft plate (78) having a central passage (86) and a plurality of tubes (92) extending through the aft plate (78), the aft plate removal tool (100) comprising: A central screw (210); a lower housing (220) attached to a central screw (210), the lower housing (220) including a plurality of spring-loaded lower housing legs (260); an upper housing (230) attached to a central screw (210), the upper housing (230) including a plurality of spring-loaded upper housing legs (290); A back plate removal tool (100) is inserted through the central passage (86) of the back plate (78); Rotation of the upper housing (230) advances the plurality of spring loaded upper housing legs (290) against the rear plate (78) until the plurality of spring loaded upper housing legs (290) push the rear plate (78) out of the plurality of tubes (92), a rear plate removal tool (100).

2. The rear plate removal tool (100) of claim 1, wherein the central screw (210) is secured within the lower housing (220).

3. The backplate removal tool (100) of claim 1, wherein the upper housing (230) rotates about a central screw (210).

4. The rear plate removal tool (100) of claim 1, wherein the plurality of spring loaded upper housing legs (270) include pads (320) thereon.

5. The back plate removal tool (100) of claim 4, wherein the pad (320) comprises a polyoxymethylene material.

6. The backplate removal tool (100) of claim 1, wherein the lower housing (220) includes a slide rod (240) secured thereto, and the upper housing (230) rotates about the slide rod (240).

7. The backplate removal tool (100) of claim 6, wherein the slide rod (240) includes a bearing (245) thereon.

8. 2. The rear plate removal tool (100) of claim 1, wherein the plurality of spring loaded lower housing legs (260) comprises a pair of spring loaded lower housing legs (260) and the plurality of spring loaded upper housing legs (290) comprises a pair of spring loaded upper housing legs (290).

9. A method of removing an aft plate (78) from a plurality of tubes (92) of a combustor (25), comprising the steps of: Inserting a back plate removal tool (100) into the back plate (78); Releasing a plurality of legs (260, 290) of a rear plate removal tool; rotating an upper housing (230) of the back plate removal tool (100) to advance a plurality of legs (260, 290) into contact with the back plate (78); further rotating the upper housing (230) to deform the rear plate (78); and further rotating the upper housing (230) to push the rear plate (78) out of the plurality of tubes (92).

10. The method of claim 9, wherein the backplate removal tool (100) is inserted through a central passage (86) of the backplate (78).

11. The method of claim 9, wherein the lower housing (220) and the upper housing (230) are attached to a central screw (210).

12. The method of claim 11, wherein the central screw (210) is fixed within the lower housing (220).

13. The method of claim 11, wherein the upper housing (230) rotates about a central screw (210).

14. The method of claim 9, wherein the plurality of legs (260, 290) comprises a plurality of spring-loaded legs.

15. The method of claim 9, wherein the plurality of legs (260, 290) comprises a pair of lower housing legs (260) and a pair of upper housing legs (290).

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