JP5787555B2 - Method for manufacturing gas turbine member - Google Patents

Description

  The present invention relates to a method for manufacturing a gas turbine member that constitutes a gas turbine and in which a cooling gas flowing through the inside is guided to the surface via a cooling hole.

  A gas turbine member constituting the gas turbine, for example, a stationary blade or a moving blade, is exposed to a high temperature of 1000 ° C. or more which is a combustion temperature of the gas turbine. Accordingly, a metal material having excellent heat resistance is used as a material for the gas turbine member, and means for actively cooling the gas turbine member is required. As a means for cooling the gas turbine member, there is a method of forming a thin low-temperature airflow layer called a cooling film on the surface of the gas turbine member. Here, the cooling film is formed by guiding the cooling gas flowing through the cooling path formed inside the gas turbine member to the surface of the gas turbine member through the cooling holes.

  Here, as one of means for forming the cooling hole through the gas turbine member, laser processing can be cited. However, when laser processing is performed, if the inner wall surface of the cooling path is damaged by the laser beam penetrating the gas turbine member, the gas turbine member is less than a predetermined strength or the flow of the cooling gas is disturbed. .

  Therefore, when the gas turbine member is manufactured, as shown in FIG. 8, by arranging a resin sheet 70 containing a dye capable of absorbing the laser beam L in advance along the inner wall surface of the cooling path 71, the cooling path 71. Conventionally, a method for preventing the inner wall surface from being damaged by the laser beam L has been used.

JP 2009-162224 A

  However, according to the conventional method for manufacturing a gas turbine member, as shown in FIG. 8, the resin is applied to the inner wall surface of the cooling path 71 around the acute corner 71 a and the rib 71 b in the cooling path 71. In some cases, the sheet 70 cannot be completely adhered, and a gap 72 is generated between the inner wall surface of the cooling path 71 and the resin sheet 70. If it does so, the laser beam L which penetrated the gas turbine member will inject into this clearance gap 72, and the problem which the inner wall surface of the cooling path 71 in which the resin sheet 70 is not arrange | positioned will be damaged arises.

  Further, depending on the shape of the resin sheet 70 and the manner in which the resin sheet 70 is arranged on the cooling path 71, a gap 72 may be generated between the adjacent resin sheets 70. In this case as well, there is a problem that the inner wall surface of the cooling path 71 is damaged by the laser light L incident on the gap 72 as described above.

  The present invention has been made in consideration of such circumstances, and its purpose is to form a cooling hole by laser processing for a gas turbine member having sharp corners, ribs, etc. in the cooling path. Another object of the present invention is to provide means for preventing the inner wall surface of the cooling path from being damaged by the laser beam penetrating the gas turbine member.

In order to achieve the above object, the present invention employs the following means. That is, in the method for manufacturing a gas turbine member according to the present invention, a cooling hole for guiding the cooling gas to the surface of the gas turbine member is provided in the laser with respect to the gas turbine member having a cooling passage through which the cooling gas flows. In the method for manufacturing a gas turbine member formed by processing, in the cooling path, a stretchable structure that can absorb laser light and fill at least a part of the cooling path in a compressed state is disposed. The laser processing is performed.

According to such a manufacturing method, even if a narrow area exists due to, for example, acute corners or ribs provided in the cooling path formed inside the gas turbine member, the cooling path is filled. The elastic structure that is deformed according to the shape of the region and is in close contact with the inner wall surface of the cooling path does not cause a gap between the elastic structure and the inner wall surface of the cooling path. Thereby, since the laser beam which penetrated the gas turbine member is reliably absorbed by the stretchable structure without irradiating the inner wall surface of the cooling path, it is possible to prevent the inner wall surface of the cooling path from being damaged.
Furthermore, according to such a manufacturing method, since the elastic structure filled in the compressed state has a force to restore the original shape, the elastic structure follows the shape of the narrow region. Deform. Thereby, a stretchable structure adheres more reliably to the inner wall surface of the cooling path.

  Moreover, the method for manufacturing a gas turbine member according to the present invention is characterized in that the stretchable structure is extracted from the cooling path after the laser processing is completed.

  According to such a manufacturing method, since the inside of the cooling path is in a hollow state by extracting the stretchable structure, the cooling gas can be circulated through the cooling path.

  Further, in the method for manufacturing a gas turbine member according to the present invention, at the end of the laser processing, the laser beam is irradiated with the laser beam so that a groove having a predetermined depth is formed in the elastic structure. The volume occupancy in the cooling path is preset.

  According to such a manufacturing method, by forming grooves in the stretchable structure, the gas used for forming the laser beam and the cooling hole can pass through without stagnation, and the gas turbine member melted by the laser beam Debris is received in the groove. As a result, the shape accuracy of the cooling holes can be maintained, and the turbulence of the flow of the cooling gas flowing through the cooling path can be prevented in advance by the fragments of the gas turbine member adhering to the inner wall surface of the cooling path. be able to.

  According to the method for manufacturing a gas turbine member according to the present invention, when a cooling hole is formed by laser processing on a gas turbine member having sharp corners, ribs, or the like in the cooling path, a laser penetrating the gas turbine member. It is possible to prevent the inner wall surface of the cooling path from being damaged by light.

It is a whole lineblock diagram showing the gas turbine provided with the turbine stationary blade concerning the embodiment of the present invention. It is a schematic perspective view which shows the turbine stationary blade which concerns on embodiment of this invention. It is a schematic perspective view explaining the process of filling a turbine stator blade with a stretchable structure among the manufacturing processes of the turbine stator blade which concerns on embodiment of this invention. It is a schematic perspective view explaining the process of performing laser processing among the manufacturing processes of the turbine stationary blade which concerns on embodiment of this invention. It is a schematic perspective view explaining the process of extracting an elastic structure from a turbine stationary blade among the manufacturing processes of the turbine stationary blade which concerns on embodiment of this invention. It is a schematic sectional drawing which shows the periphery of the cooling hole in a blade | wing main body. It is a graph which shows the relationship between the volume occupation rate of the elastic structure in a cooling path, and the volume reduction rate of the elastic structure at the time of laser beam irradiation. The schematic sectional drawing explaining the problem about the manufacturing method of the gas turbine member which concerns on a prior art example.

  Embodiments of the present invention will be described below with reference to the drawings. First, the gas turbine member manufactured by the manufacturing method of the gas turbine member which concerns on embodiment of this invention is demonstrated. In this embodiment, a turbine stationary blade constituting a gas turbine will be described as an example of a gas turbine member.

  FIG. 1 is an overall configuration diagram illustrating a gas turbine 1 including a turbine stationary blade 10 according to the present embodiment. The gas turbine 1 is provided at the most upstream position along the fluid flow direction F to generate compressed air, and provided downstream thereof to inject fuel into the compressed air for combustion. Are provided with a combustor 3 that generates combustion gas, and a turbine 4 that is provided downstream of the combustor 3 and is driven to rotate by the combustion gas.

  As shown in FIG. 1, the turbine 4 is provided on the outer periphery of the rotor 5 and has a turbine casing 41 in which a combustion gas flow path (not shown) is formed. The turbine 4 protrudes from the outer peripheral surface of the rotor 5 and is predetermined in the circumferential direction. A plurality of turbine blades 42 provided at intervals, and a plurality of turbine stationary blades 10 protruding from the inner peripheral surface of the turbine casing 41 and provided at predetermined intervals in the circumferential direction are provided. The turbine rotor blade 42 and the turbine stationary blade 10 are provided with a plurality of stages alternately along the axial direction of the rotor 5.

  The turbine stationary blade 10 plays a role of decelerating the combustion gas and increasing the pressure. FIG. 2 is a schematic perspective view showing the turbine stationary blade 10. In FIG. 2, for convenience of explanation, a part thereof is shown in a broken state. As shown in FIGS. 2 and 3, the turbine stationary blade 10 includes a blade body 11 having a streamlined section and extending in the radial direction of the rotor 5, and a pair of shrouds attached to both longitudinal ends of the blade body 11. 12A and 12B (one illustration is omitted in FIG. 2).

  As shown in FIG. 2, the blade body 11 is formed so as to cross the cooling passage 13 formed through the inside thereof, a plurality of cooling holes 14 formed on the surface thereof, and the cooling passage 13. A rib 15 for structurally reinforcing the main body 11.

  The cooling path 13 is a flow path through which a cooling gas (not shown) for cooling flows. As shown in FIG. 2, the cooling path 13 is formed so as to penetrate the blade main body 11 in the longitudinal direction, and both end portions in the longitudinal direction are opened on both end surfaces of the blade main body 11.

  The cooling hole 14 is a flow path for guiding the cooling gas flowing through the cooling path 13 to the surface of the blade body 11. As shown in FIG. 2, the cooling hole 14 is formed so as to extend in the thickness direction of the blade body 11, that is, in a direction substantially orthogonal to the longitudinal direction, one end of which opens to the cooling passage 13, and the other end of the blade body 11. 11 is open to the surface 11a. The cooling holes 14 are arranged at predetermined intervals in the longitudinal direction of the blade body 11 and a plurality of rows are formed in a direction substantially orthogonal to the longitudinal direction.

  The pair of shrouds 12 </ b> A and 12 </ b> B connects the turbine stationary blades 10 provided in the circumferential direction to each other in the circumferential direction at the base end portion and the tip end portion. As shown in FIG. 3, communication holes 16 </ b> A and 16 </ b> B are formed through the pair of shrouds 12 </ b> A and 12 </ b> B in the thickness direction and having substantially the same cross-sectional shape as the cooling passage 13 of the blade body 11. Thereby, the cooling path 13 of the blade body 11 is communicated to the outside through the communication holes 16A and 16B of the shrouds 12A and 12B at both ends.

  Next, the manufacturing method of the turbine stationary blade 10 according to the embodiment of the present invention and the operation and effect thereof will be described in order. 3 to 5 are schematic perspective views for explaining the manufacturing process of the turbine vane 10, wherein FIG. 3 shows the process of filling the stretchable structure, FIG. 4 shows the laser processing process, and FIG. Respectively show the process of extracting an elastic structure.

  An operator who manufactures the turbine vane 10 first fills the inside of the turbine vane 10 with a stretchable structure. That is, as shown in FIG. 3, the operator fixes one shroud 12A constituting the turbine vane 10 to the jig J, and then enters the cooling passage 13 of the blade body 11 through the communication hole 16B of the other shroud 12B. The elastic structure 17 is filled.

  This stretchable structure 17 is a sponge-like member having stretchability formed by foaming a heat resistant resin containing an organic light absorber. As shown in FIG. 3, the cross section of the stretchable structure 17 is substantially the same shape and slightly larger than the cross section of the cooling passage 13 of the blade body 11. Further, the longitudinal dimension of the stretchable structure 17 is formed to be approximately the same as or longer than the longitudinal dimension of the cooling path 13. Therefore, the stretchable structure 17 is in a compressed state in a state where the cooling path 13 is filled, and has a force to restore the original shape. As a result, even when a narrow region exists due to the formation of the acute corner 18 or the rib 15 inside the cooling passage 13, the elastic structure 17 is deformed following the shape of the narrow region. The stretchable structure 17 is in close contact with the inner wall surface 13a of the cooling path 13 without a gap.

  Here, as the heat resistant resin which is a raw material of the stretchable structure 17, it is preferable to use a thermoplastic resin having a melting point of 200 ° C. or higher, preferably 250 ° C. or higher. Specific examples of the thermoplastic resin include polyphenylene sulfide, polyamide 66, polyamide 46, polyethylene terephthalate, polycyclohexanedimethylene terephthalate, polyethylene naphthalate, polytetrafluoroethylene, perfluoroalkoxyalkane, and ethylene-tetrafluoroethylene copolymer. It is done.

The organic light absorber contained in the heat-resistant resin has a property of absorbing laser light having a specific wavelength, and is appropriately selected according to the wavelength of the laser light used in the laser processing step described later. can do. For example, when an Nd: YAG laser is used, the organic light absorber is preferably one that absorbs laser light having a wavelength in the vicinity of 1064 nm.
In particular, as the organic light absorber, an azine dye that does not contain a metal as a constituent element is suitable. This azine-based dye absorbs laser light in the above wavelength region and is excellent in heat resistance and light resistance. Specific examples of the azine dye include LTW-8170C, LTW-8400C, LTW-8950H, LTW-8000C, LWT-8901H and LAW-4801 manufactured by Orient Chemical Industries.

  In addition to the sponge-like member as in this embodiment, the stretchable structure 17 is packed with a three-dimensional fabric, a steel wool-like member, a cotton-like member, or a gel-like member in a bag. Or a balloon-like member can be used.

  Next, the operator forms a cooling hole 14 in the blade body 11 by laser processing. That is, as shown in FIG. 4, the worker irradiates the surface 11 a of the blade body 11 with the laser light L from the tip nozzle N of the laser irradiation device S, thereby forming the cooling hole 14 reaching the cooling path 13. . Then, the operator drives the machining head H of the laser irradiation apparatus S to appropriately move the position of the tip nozzle N in the vertical direction and the horizontal direction, thereby sequentially forming a plurality of cooling holes 14.

  Here, as shown in FIG. 2, even in a narrow region where the sharp corners 18 and the ribs 15 are formed in the cooling path 13, the stretchable structure 17 is closely attached to the inner wall surface 13 a of the cooling path 13 without a gap. Yes. Therefore, even if the laser beam L penetrates the blade body 11 and enters such a narrow region, the laser beam L is reliably absorbed by the stretchable structure 17, so The wall surface 13a is not irradiated. As a result, there is a problem that the blade body 11 falls below a predetermined strength due to damage of the inner wall surface 13a of the cooling path 13 by the laser light L, and a problem that the flow of the cooling gas flowing through the cooling path 13 is disturbed. It can be prevented in advance.

  However, when the stretchable structure 17 is in close contact with the inner wall surface 13a of the cooling path 13 without a gap, the gas used for forming the cooling holes 14 stays in the interior, so that the shape accuracy of the cooling holes 14 deteriorates. Occurs. Further, spatter and dross generated when the laser beam L penetrates the blade body 11, that is, a small piece of the melted blade body 11 is bounced back by the stretchable structure 17, thereby cooling the inner wall surface 13 a of the cooling path 13. The problem of adhering to the periphery of the opening of the hole 14 arises. Therefore, in order to prevent the occurrence of this problem, it is preferable to appropriately set the volume occupation rate of the elastic structure 17 in the cooling path 13 when the elastic structure 17 is filled in the cooling path 13. is there.

  More specifically, as shown in FIG. 6, when the stretchable structure 17 is irradiated with the laser light L penetrating the blade body 11, the stretchable structure 17 is melted and vaporized. A groove 19 is formed between the inner wall surface 13 a and the stretchable structure 17. Then, when the laser beam L penetrates the blade body 11, the gas used for forming the laser beam L and the cooling hole 14 passes through the cooling hole 14 without stagnation. Further, since the spatter 20 generated when the laser beam L penetrates the blade body 11 accumulates in the groove 19, the spatter 20 is prevented from adhering to the periphery of the opening of the cooling hole 14 in the inner wall surface 13 a of the cooling path 13. be able to.

  Here, FIG. 7 is a graph showing the relationship between the volume occupancy rate of the stretchable structure 17 in the cooling path 13 and the volume reduction rate of the stretchable structure 17 at the time of laser light irradiation. The occupancy is shown, and the vertical axis shows the volume reduction rate. According to this figure, the higher the volume occupancy rate, that is, the more the stretchable structure 17 is filled in the cooling path 13 without gaps, the greater the volume reduction rate, that is, the more stretchable structures 17 are more sensitive. Tend to create a wide space. However, if the volume reduction rate is too large, the laser beam L penetrates the stretchable structure 17, thereby causing a problem of damaging the inner wall surface 13 a of the cooling path 13. On the other hand, if the volume occupancy is too low, a gap is generated between the elastic structure 17 and the inner wall surface 13a of the cooling path 13 as described above. The problem which damages the inner wall surface 13a arises. Therefore, the operator needs to appropriately set the volume occupation ratio of the stretchable structure 17 in consideration of this balance.

  Finally, the operator pulls out the stretchable structure 17 from the inside of the turbine stationary blade 10. That is, as shown in FIG. 5, the operator pulls out the stretchable structure 17 filled in the cooling passage 13 of the blade body 11 to the outside of the turbine stationary blade 10 through the communication hole 16B of the other shroud 12B. At this time, the sputter 20 accommodated in the groove 19 of the stretchable structure 17 is also recovered outside the turbine stationary blade 10.

  In the present embodiment, the entire stretchable structure 17 is filled with the cooling path 13. However, the present invention is not limited to this, and it is sufficient that the stretchable structure 17 is filled at least around the portion where the laser beam L is irradiated. . In the present embodiment, the elastic structure 17 is filled in the cooling path 13 in a compressed state. However, as long as the elastic structure 17 is in close contact with the inner wall surface 13a of the cooling path 13 without a gap, it is not necessarily in the compressed state.

  Moreover, although this embodiment demonstrated the turbine stationary blade 10 as an example of the gas turbine member which concerns on this invention, the turbine blade 42 and another member may be sufficient as a gas turbine member.

  The various shapes, combinations, operation procedures, and the like of the constituent members shown in the above-described embodiments are merely examples, and various changes can be made based on design requirements and the like without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 Gas turbine 2 Compressor 3 Combustor 4 Turbine 5 Rotor 10 Turbine stationary blade 11 Blade body 11a Surface (blade body)
12A shroud 12B shroud 13 cooling path 13a inner wall surface (cooling path)
14 Cooling hole 15 Rib 16A Communication hole 16B Communication hole 17 Stretchable structure 18 Corner 19 Groove 20 Sputter 41 Turbine casing 42 Turbine blade 70 Resin sheet 71 Cooling path 71a Corner 71b Rib 72 Clearance F Flow direction H Processing head J Jig L Laser beam N Tip nozzle S Laser irradiation device

Claims (3)

In a gas turbine member manufacturing method in which a cooling hole for guiding the cooling gas to the surface of the gas turbine member is formed by laser processing with respect to the gas turbine member having a cooling path through which the cooling gas flows.
A gas turbine characterized in that the laser processing is performed in a state in which a stretchable structure capable of absorbing laser light and filling at least a part of the cooling path in a compressed state is disposed in the cooling path. Manufacturing method of member.   The method for manufacturing a gas turbine member according to claim 1, wherein the stretchable structure is extracted from the cooling path after the laser processing is completed. At the end of the laser processing, a volume occupation ratio in the cooling path of the stretchable structure is set in advance so that a groove having a predetermined depth is formed in the stretchable structure by irradiation with the laser light. The manufacturing method of the gas turbine member of Claim 1 or 2 .

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