Rear inner cover removal method and tool for burners with micromixer tubes

Abstract

The invention relates to a rear inner cover plate removal method and tool for a combustor with micro-mixer tubes. The present application provides a back plate removal tool (100) for servicing a combustor (25) including a back plate (78) having a central channel (86) and a plurality of tubes (92) extending through the back plate (78). The back plate removal tool (100) includes a center screw (210), a lower housing (220) attached to the center screw (210), the lower housing (220) including a plurality of spring-loaded lower housing legs (260), and an upper housing (230) attached to the center screw (210), the upper housing (230) including a plurality of spring-loaded upper housing legs (290). The back plate removal tool (100) is inserted through a central passage (86) of the back plate (78) such that rotation of the upper housing (230) urges the spring-loaded upper housing foot (290) against the back plate (78) until the spring-loaded upper housing foot (290) urges the back plate (78) away from the tube (92).

Description

Technical Field

[0001] The present application and the resultant patent relate generally to gas turbine engines and, more particularly, to improved methods and tools for safely removing an aft inner cover plate from a micro-mixer head end of a combustor during maintenance and replacement. Background Art

[0002] A gas turbine engine typically includes a compressor for compressing ambient air and a plurality of burners for mixing the air flow with a fuel flow to produce hot combustion gases. The turbine receives the hot combustion gas flow and extracts energy from it to provide power to the compressor and to produce output power for an external load such as a generator. The burners may be arranged annularly between the compressor and the turbine.

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

[0004] Each micro-mixer tube generally extends axially through the fuel plenum and the cooling air plenum. Compressed air is directed through the inlet of each micro-mixer tube upstream of the fuel plenum. Fuel is injected into the micro-mixer tube through one or more fuel ports defined in each tube. The fuel and compressed air are mixed in the micro-mixer tubes and then flow out of the outlet of each tube and into the combustion chamber or combustion zone for combustion.

[0005] During operation of the combustor, the downstream or end portion of each micro-mixer tube is exposed to extreme temperatures due to its proximity to the combustion chamber and / or the combustion flame. Likewise, the rear plate through which the micro-mixer tube extends may also become deformed or dented due to the harsh conditions. Over time, various factors including thermal stress, mechanical fatigue, and combustion dynamics or vibrations may adversely affect the operating conditions of the bundle fuel injector, requiring regular inspection and, in some cases, repair or refurbishment of the components therein. In particular, the dents and tight fit of the rear plate may cause the micro-mixer tubes that pass through the rear plate to bind. However, removing the rear plate by moving the rear plate to the right may damage the fuel injector. Summary of the invention

[0006] Thus, the present application and the resulting patent provide a back plate removal tool for servicing a burner. The burner includes a back plate having a central passage and a plurality of tubes extending through the back plate. The back plate removal tool includes a central screw, a lower housing attached to the central screw, and an upper housing attached to the central screw, the lower housing including a plurality of spring-loaded lower housing legs, and the upper housing including a plurality of spring-loaded upper housing legs. The back plate removal tool is inserted through the central passage of the back plate such that rotation of the upper housing causes the spring-loaded upper housing legs to advance against the back plate until the spring-loaded upper housing legs push the back plate away from the tubes.

[0007] The present application and the resulting patent also provide a method for removing a back plate from a plurality of tubes of a burner. The method may include the steps of inserting a back plate removal tool through the back plate, releasing a plurality of legs of the back plate removal tool, rotating an upper housing of the back plate removal tool to advance the plurality of legs into contact with the back plate, further rotating the upper housing to deform the back plate, and further rotating the upper housing to push the back plate away from the tubes.

[0008] These and other features and improvements of the present application and the resultant patent will become apparent to one of ordinary skill in the art upon reading the following detailed description, taken in conjunction with the several drawings and the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a schematic diagram of a gas turbine engine including a compressor, a combustor, a turbine, and an external load.

[0010] Figure 2 It is available with Figure 1 Schematic diagram of a combustor used with a gas turbine engine.

[0011] Figure 3 yes Figure 2 A perspective view of a fuel nozzle assembly of a combustor.

[0012] Figure 4 It is available with Figure 2 A schematic diagram of a fuel injector used with a burner.

[0013] Figure 5 It is available with Figure 2 A perspective view of an alternative embodiment of a fuel nozzle assembly for use with a combustor.

[0014] Figure 6 is a perspective view of an example of a backplane removal tool as may be described herein.

[0015] Figure 7 Is installed with Figure 6 A partial cross-sectional view of the burner of the rear plate removal tool.

[0016] Figure 8 is a partial perspective view of an end plate of a burner with a back plate removal tool installed therein.

[0017] Fig. 9 is a plan view of an alternative embodiment of a backplate removal tool as described herein.

[0018] Fig.10 yes Fig. 9 Cross-sectional view of the rear plate removal tool.

[0019] Fig.11 yes Fig. 9 Another cross-sectional view of the rear panel removal tool. DETAILED DESCRIPTION

[0020] Referring now to the drawings, in which like numerals refer to like elements throughout the several views, Figure 1 A schematic diagram of a gas turbine engine 10 as described herein is shown. The gas turbine engine 10 may include a compressor 15. The compressor 15 compresses an incoming air flow 20. The compressor 15 delivers the compressed air flow 20 to a plurality of combustor cans 25. The combustor cans 25 mix the compressed air flow 20 with a pressurized fuel flow 30 and ignite the mixture, thereby producing 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 positioned in a circumferential array or the like. Alternatively, the combustor 25 may be an annular combustor. The combustion gas flow 35 is then delivered to a turbine 40. The combustion gas flow 35 drives the turbine 40 to produce mechanical work. The mechanical work produced in the turbine 40 drives the compressor 15 through a rotor shaft 45. The turbine 40 and the rotor shaft 45 may also drive an external load 50 such as a generator.

[0021] The gas turbine engine 10 can use natural gas, various types of synthetic gas, liquid fuels and / or other types of fuels and blends thereof. The gas turbine engine 10 can be any of a variety of different gas turbine engines provided by General Electric Company of Schenectady, New York, including but not limited to those of heavy-duty gas turbine engines such as the 7 series or 9 series. The gas turbine engine 10 can be part of a single cycle or combined cycle power generation system or other types of power generation systems. The gas turbine engine 10 can have different configurations and can use other types of components. Other types of gas turbine engines can also be used herein. Multiple gas turbine engines, other types of turbines, and other types of power generation equipment can also be used together herein.

[0022] Figure 25 is a partial cross-sectional view of a combustor 25. The combustor 25 may include a plurality of fuel injectors 52 therein. The fuel nozzles 52 may be incorporated into a fuel nozzle assembly 53. In this example, the fuel injectors 52 may be tube-bundle 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 surrounding the combustor 25. The high-pressure plenum 56 may be in fluid communication with the compressor 15 or other source for supplying the air flow 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 fuel flow 30.

[0023] The fuel injector 52 extends downstream from the end cover 58. The fuel injector 52 may be fluidly connected to 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 injector 52. An annular liner 62, such as a combustion liner and / or a transition duct, surrounds one end of a downstream end 64 of the fuel injector 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.

[0024] In operation, the air flow 20 is directed toward the end cover 58 where it reverses direction and flows through one or more fuel injectors 52. The fuel flow 30 is provided to the fuel injectors 52, and the fuel flow 30 and the air flow 20 are premixed or combined within the fuel injectors 52 and then injected into the combustion chamber 66 for combustion.

[0025] Figure 3 is a perspective view of the fuel injector assembly 53, and Figure 4 is a cross-sectional view of an example of the above-described fuel injector 52. 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 separated from a downstream plate 74. A fuel plenum 76 may be defined between the upstream plate 72 and the downstream plate 74. The fluid conduit 60 provides a fuel flow 30 to the fuel plenum 76.

[0026] The rear plate 78 is disposed at the downstream or rearward end of the fuel injector 52. The rear plate 78 extends radially outward and circumferentially through the rearward end relative to the axial centerline. The rear plate 78 at least partially defines a plurality of tube end passages 82 extending generally axially therethrough. An impact plate 84 is disposed upstream of the rear plate 78. The impact plate 84 may be welded, brazed, or otherwise coupled to the rear plate 78. The rear plate 78 and / or the impact plate 84 may at least partially define a central passage 86 extending generally axially therethrough. A fluid cartridge insert 88 may be coupled to the rear plate 78 at the central passage 86. The rear plate 78, the impact plate 84, and related components herein may be described as an inner cover assembly 94.

[0027] 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 extending generally parallel to one another along or parallel to the axial centerline of the fuel injector 52. The micro-mixer tubes 92 extend downstream from the fuel plenum 76 toward the rear plate 78 and / or the combustion chamber 66. A portion of the micro-mixer tubes 92 extends through the rear plate 78. Each micro-mixer tube 92 is generally aligned with a corresponding tube end channel 82. The micro-mixer tubes 92 may be arranged in multiple rows or other arrangements. Similarly, Figure 5 An alternative embodiment of the fuel nozzle assembly 53 is shown with the addition of a central liquid fuel nozzle 96 .

[0028] Figure 6 An aft plate removal tool 100 is shown that may be used as described herein. In this example, an internal aft plate removal tool 105 is shown. As the name implies, the internal aft plate removal tool 105 is used within the combustor 25 to remove the aft plate 78 and the inner cover assembly 94. Specifically, the internal aft plate removal tool 105 may be used to trim and remove the aft plate 78 without damaging any of the micro-mixer tubes 92. The internal aft plate removal tool 105 may be used with Figure 3 The fuel nozzle assembly 53 is used together.

[0029] The internal back plate removal tool 105 may include a base plate 110 having a base plate hole 120, a threaded insert 130 located within the base plate hole 120, and a threaded rod 140 extending through the threaded insert 130. The threaded rod 140 may have a replaceable tip 150 located at its rear end. The replaceable tip 150 may be made of Delrin (polyoxymethylene) or a similar material to prevent wear due to frictional contact with the back plate 78. The threaded rod 140 may also have an external sleeve 160 to protect the adjacent micro-mixer tube 92. The threaded rod 140 may have any convenient length and other dimensions. The base plate 110 may have a plurality of attachment holes 170 therein. The internal back plate removal tool 105 may be attached to the end cover 58 of the combustor 25 using a plurality of mounting bolts 180, etc. Other components and other configurations may also be used herein.

[0030] Figure 7 and Figure 8 The internal back plate removal tool 105 is shown in use. The internal back plate removal tool 105 can be inserted into the central passage 86 of the combustor 25. The internal back plate removal tool 105 can be advanced therein until the replaceable tip 150 contacts the back plate 78. The bottom plate 110 can be attached to the end cover 48 by attaching the mounting bolts 180. Once securely fixed in place, the threaded rod 140 can be rotated to advance. Specifically, the threaded rod 140 is rotated within the threaded insert 130 of the bottom plate 110.

[0031] When the threaded rod 140 is advanced to contact the rear plate 78, the threaded rod 140 flattens any deformation in the rear plate 78. When the rear plate 78 is flattened, the rear plate 78 and the inner cover assembly 94 begin to separate from the micro-mixer tube 92. The threaded rod 140 continues to advance until the rear plate 78 and the inner cover assembly 94 are completely pushed away from the micro-mixer tube 92. Therefore, the advancement of the threaded rod 140 allows the rear plate 78 and the inner cover assembly 94 to slide freely away from the micro-mixer tube 92 without causing any damage to them. Then, the threaded rod 140 can be rotated in the opposite direction, and the internal rear plate removal tool 105 can be disengaged from the end cover 58. The internal rear plate removal tool 105 can be removed from the combustor 25.

[0032] Figures 9 to 11 Another embodiment of the aft plate removal tool 100 is shown. In this example, an external aft plate removal tool 200 is shown. As the name implies, the external aft plate removal tool 200 is used to remove the aft plate 78 and the inner cap assembly 94 from the outside of the combustor 25. Once the center liquid fuel nozzle 96 has been removed, the external aft plate removal tool 200 can be used with the combustor 25 to remove the aft plate 78 and the inner cap assembly 94. Figure 5 Used together with the fuel nozzle assembly 95.

[0033] The external rear plate removal tool 200 may include a central screw 210. A lower housing 220 and an upper housing 230 may be mounted on 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 bars 240 fixed therein. Each slide bar 240 may have a slide bar bearing 245 thereon. The upper housing 230 may be rotatably mounted to the central screw 210. The upper housing 230 may also have complementary slide bar holes 250 formed therein. The upper housing 230 may rotate relative to the lower housing 220 along the central screw 210 and the slide bars 240.

[0034] The lower housing 220 may have a pair of lower legs 260 attached thereto. Each of the pair of lower legs 260 may be attached to the lower housing 220 by a lower pin 270. Each of the pair of lower legs 260 may be spring loaded via a lower spring 280. The lower legs 260 may rotate via the lower spring 280. Likewise, the upper housing 230 may have a pair of upper legs 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 rotate via the upper spring 310. Each upper leg 290 may have an upper leg pad 320 thereon. The upper leg pad 320 may be made of Delrin (polyoxymethylene) or a similar material to prevent frictional contact with the rear plate 78. The lower and upper legs 260, 290 may be retracted within the housings 220, 230 via set screws 330 or the like. Other components and other configurations may also be used herein.

[0035] In use, the lower leg 260 and the upper leg 290 can be retracted via the fixing screw 330. The external rear plate removal tool 200 can be inserted into the central channel 86 of the rear plate 78 and the inner cover assembly 94. Once the rear plate 78 is cleared, the lower leg 260 and the upper leg 290 can be extended. The lower leg 260 can be positioned around 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 can be moved upward against the rear plate 78. When the upper housing 230 is advanced into contact with the rear plate 78, the upper leg 290 can flatten any deformation in the rear plate 78. When the rear plate 78 is flattened, the rear plate 78 and the inner cover assembly 94 begin to separate from the micro-mixer tube 92. The upper housing 230 and the upper leg 290 continue to advance until the rear plate 78 and the inner cover assembly 94 are completely pushed away from the micro-mixer tube 92.

[0036] Thus, advancement of the upper housing 230 allows the aft plate 78 and the inner cover assembly 94 to slide freely away from the micro-mixer tube 92. The aft plate 78 and the external aft plate removal tool 200 can then be removed from the combustor 25. Thus, the external aft plate removal tool 200 provides for safe removal of the aft plate 78 and the inner cover assembly 94 from the micro-mixer tube 92 in a quick and efficient manner.

[0037] It will be apparent that the foregoing relates only to certain embodiments of the present application and the resultant patent. Numerous changes and modifications may be made herein by one of ordinary skill in the art without departing from the general spirit and scope of the invention as defined by the appended claims and their equivalents.

[0038] Further aspects of the invention are provided by the subject matter of the following clauses:

[0039] 1. A back plate removal tool for maintaining a burner, the burner comprising a back plate having a central channel and a plurality of tubes extending through the back plate; the back plate removal tool comprising: a central screw; a lower housing, the lower housing being attached to the central screw, the lower housing comprising a plurality of spring-loaded lower housing legs; and an upper housing, the upper housing being attached to the central screw, the upper housing comprising a plurality of spring-loaded upper housing legs; wherein the back plate removal tool is inserted through the central channel of the back plate; and wherein rotation of the upper housing causes the plurality of spring-loaded upper housing legs to advance against the back plate until the plurality of spring-loaded upper housing legs push the back plate away from the plurality of tubes.

[0040] 2. A rear panel removal tool according to any preceding clause, wherein the central screw is fixed within the lower housing.

[0041] 3. A rear plate removal tool according to any preceding clause, wherein the upper housing rotates about the central screw.

[0042] 4. A rear plate removal tool according to any preceding clause, wherein the plurality of spring-loaded upper housing feet include pads thereon.

[0043] 5. A back plate removal tool according to any preceding clause, wherein the pad comprises a polyoxymethylene material.

[0044] 6. A rear plate removal tool according to any preceding clause, wherein the lower housing includes a sliding rod fixed therein, and wherein the upper housing rotates about the sliding rod.

[0045] 7. A rear panel removal tool according to any preceding clause, wherein the sliding rod comprises a bearing thereon.

[0046] 8. A rear plate removal tool according to any preceding clause, wherein the plurality of spring-loaded lower housing feet comprises a pair of spring-loaded lower housing feet, and wherein the plurality of spring-loaded upper housing feet comprises a pair of spring-loaded upper housing feet.

[0047] 9. A method for removing a back plate from a plurality of tubes of a burner, the method comprising: inserting a back plate removal tool through the back plate; releasing a plurality of legs of the back plate removal tool; rotating an upper housing of the back plate removal tool to advance a plurality of the plurality of legs into contact with the back plate; further rotating the upper housing to deform the back plate;

[0048] and further rotating the upper housing to push the rear plate away from the plurality of tubes.

[0049] 10. A method according to any preceding clause, wherein the back plate removal tool is inserted through a central passage of the back plate.

[0050] 11. A method according to any preceding clause, wherein the lower housing and the upper housing are attached to a central screw.

[0051] 12. A method according to any preceding clause, wherein the central screw is fixed within the lower housing.

[0052] 13. A method according to any preceding clause, wherein the upper housing rotates about the central screw.

[0053] 14. A method according to any preceding clause, wherein the plurality of legs comprises a plurality of spring-loaded legs.

[0054] 15. A method according to any preceding clause, wherein the plurality of feet comprises a pair of upper housing feet and a pair of lower housing feet.

[0055] 16. A method according to any preceding clause, wherein the pair of upper housing feet include pads thereon.

[0056] 17. A method according to any preceding clause, wherein the pad comprises a polyoxymethylene material.

[0057] 18. A method according to any preceding clause, wherein the lower housing includes a sliding rod fixed therein, and wherein the upper housing rotates about the sliding rod.

[0058] 19. A method according to any preceding clause, wherein the sliding rod comprises a bearing thereon.

Claims

1. A back plate removal tool (100) for servicing a burner (25), the burner (25) comprising a back plate (78) having a central passage (86) and a plurality of tubes (92) extending through the back plate (78); The rear plate removal tool (100) comprises: A central screw (210); a lower housing (220) attached to the central screw (210), the lower housing including a plurality of spring-loaded lower housing feet (260); and an upper housing (230) attached to the central screw (210), the upper housing (230) comprising a plurality of spring-loaded upper housing feet (290); wherein the rear panel removal tool (100) is inserted through the central passage (86) of the rear panel (78); and Rotation of the upper housing (230) causes the plurality of spring-loaded upper housing legs (290) to advance against the rear plate (78) until the plurality of spring-loaded upper housing legs (290) push the rear plate (78) away from the plurality of tubes (92).

2. The rear panel removal tool (100) according to claim 1, wherein the central screw (210) is fixed within the lower housing (220).

3. The rear plate removal tool (100) according to claim 1, wherein the upper housing (230) rotates around the central screw (210).

4. The backplate removal tool (100) of claim 1, wherein the plurality of spring-loaded upper housing feet (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 rear plate removal tool (100) according to claim 1, wherein the lower housing (220) includes a slide bar (240) fixed therein, and wherein the upper housing (230) rotates around the slide bar (240).

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

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

9. A method of removing a back plate (78) from a plurality of tubes (92) of a burner (25), the method comprising: inserting a back plate removal tool (100) through the back plate (78); releasing a plurality of legs (260, 290) of the rear panel removal tool; Rotating the upper housing (230) of the rear panel removal tool (100) to push a plurality of the plurality of legs (260, 290) into contact with the rear panel (78); further rotating the upper housing (230) to deform the rear plate (78); and The upper housing (230) is further rotated to push the rear plate (78) away from the plurality of tubes (92).

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

11. The method of claim 9, wherein the lower housing (220) and the upper housing (230) are attached to the 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 an upper housing (230) rotates around the 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 feet (260, 290) includes a pair of lower housing feet (260) and a pair of upper housing feet (290).

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