Rotor disk, rotor shaft, turbine rotor and gas turbine
Patent Information
- Authority / Receiving Office
- DE · DE
- Patent Type
- Patents
- Current Assignee / Owner
- MITSUBISHI HEAVY IND LTD
- Filing Date
- 2020-04-23
- Publication Date
- 2026-07-02
Abstract
Description
Technical field
[0001] The present invention relates to a rotor disk, a rotor shaft, a turbine rotor and a gas turbine.
[0002] Priority is claimed by the Japanese patent application No. 2019-097549 filed on May 24, 2019, the contents of which are incorporated herein by reference. State of the art
[0003] A gas turbine contains a compressor that compresses air to produce compressed air, a combustion chamber that burns fuel in the compressed air to produce combustion gas, and a turbine that is driven by the combustion gas. The turbine contains a turbine rotor that rotates around an axis and a turbine casing that covers the turbine rotor. The turbine rotor contains a rotor shaft that rotates around the axis and extends in an axial direction, and several rows of rotor blades. The multiple rows of rotor blades are arranged in the axial direction. Each of the multiple rows of rotor blades contains several rotor blades arranged circumferentially with respect to the axis. For example, several rotor disks are stacked in the axial direction to form the rotor shaft.
[0004] The following PTL 1 discloses a configuration of a rotor disk. The rotor disk comprises a radial outer surface facing a radial outside; a radial inner surface facing a radial inside; several blade root grooves extending from the radial outer surface to the radial inside and arranged circumferentially; and several holes extending from the radial inside surface to the radial outside. A blade root of a rotor blade is located in each of the several blade root grooves. The several holes contain several first cooling holes and several second cooling holes. The first cooling hole is provided for each of the several blade root grooves. The first cooling hole communicates with the blade root groove. Air that has flowed through a space on the radial inside of the rotor disk from the radial inner surface flows through the first cooling hole.Air flows into a cooling airflow path in the rotor blade through the blade root groove to cool the rotor blade. The second cooling hole is located between the first several cooling holes.
[0005] When the rotor disk rotates around an axis, tensile stress is generated within it. This stress concentrates near the opening of a cooling hole. As the stress concentration near the opening increases and the stress concentration factor (maximum stress / average stress) rises, the durability of the rotor disk decreases. Therefore, to reduce the stress concentration near the opening of the first cooling hole, PTL 1 incorporates a second cooling hole positioned between two adjacent first cooling holes in the circumferential direction, thus reducing the stress concentration near the opening of the first cooling hole. List of citations from patent literature
[0006] [PTL 1] Japanese unexamined patent application publication no. 2009-203870 Summary of the invention: Technical problem
[0007] One object of the present invention is to provide a technique that is able to reduce stress concentration near the opening of a cooling hole and improve the durability of a rotor disk. Solution to the problem
[0008] According to one aspect of the invention, to achieve the above objective, a rotor disk is provided comprising: a radial outer surface, which is radially outside and located one side away from an axis in a radial direction with respect to the axis; a radial inner surface, which faces radially inside and is located on the radial inside of the radial outer surface; several blade root grooves, which extend from the radial outer surface to the radial inside and are arranged circumferentially with respect to the axis; and several groups of holes, which are formed for the several blade root grooves and are arranged circumferentially. Each of the several groups of holes contains holes that include a cooling hole penetrating from the radial inner surface to the radial outer surface.The width of each of the multiple hole groups in the circumferential direction is greater than the width of each of the multiple hole groups in an axial direction in which the axis extends, and is less than a minimum distance between the multiple hole groups in the circumferential direction. The cooling hole communicates with an inner surface of the blade root groove.
[0009] In this type of rotor disk, a cooling medium can be channeled through a cooling hole and the blade root groove in a space on the radial inner surface of the disk to a rotor blade. As the rotor disk rotates around its axis, tensile stress is generated within it. This tensile stress concentrates near the opening of the cooling hole. As the distance between the openings of two holes decreases, the stress concentration factor decreases. This is because stress generated around the opening of one hole is distributed around the opening of the adjacent hole.
[0010] In this respect, a circumferential group width, which is the width of the hole group in the circumferential direction, is greater than an axial group width, which is the width of the hole group in the axial direction, and is smaller than a minimum group spacing, which is the minimum distance between the multiple hole groups in the circumferential direction. It is assumed that the hole group contains multiple holes, including the cooling hole. In this case, the hole spacing between two holes in a hole group in the circumferential direction is smaller than the minimum group spacing. Therefore, in this case, the hole spacing between the multiple holes in a hole group is smaller than if all the holes formed in the rotor disk were arranged at equal intervals in the circumferential direction. Consequently, in this case, the stress concentration near the cooling hole opening can be reduced, and the durability of the rotor disk can be improved.
[0011] Furthermore, it is assumed that the circumferential width of the cooling hole's cross-section is greater than its axial width. As described above, the stress concentration factor decreases when the distance between the openings of the two holes is reduced. Therefore, when the distance between the openings of the two holes is reduced and the openings of the two holes are connected to form a single opening, the stress generated around the opening of the hole is reduced. This is because the stress is distributed in the direction in which the two holes are connected. In this case, the cooling hole has a shape in which the two holes are connected circumferentially. For this reason, the stress generated around the opening of the cooling hole is distributed circumferentially.Therefore, in this case too, the stress concentration near the opening of the cooling hole can be reduced and the durability of the rotor disk improved.
[0012] In this aspect of the rotor disk, each of the multiple hole groups can contain several holes that are recessed from the radial inner surface to the radial outer surface and arranged in the circumferential direction. In this case, at least one of the multiple holes is the cooling hole.
[0013] This aspect applies when the hole group contains multiple holes, including the cooling hole described above. Therefore, in this case, the stress concentration near the opening of the cooling hole can be reduced, and the durability of the rotor disk can be improved.
[0014] In the case of the rotor disk according to this aspect, where the hole group contains several holes, a maximum hole spacing of the distances between the several holes of the hole group in the circumferential direction can be smaller than the minimum distance of the distances between the several hole groups in the circumferential direction.
[0015] In the case of the rotor disk according to one of the above aspects, where the hole group contains the multiple holes, all of the multiple holes in the hole group can be the cooling holes.
[0016] Furthermore, in the case of the rotor disk, according to this aspect, the width of an inner opening, which is an opening of the cooling hole on the radial inner surface, can be greater in the circumferential direction than the width of the inner opening in the axial direction.
[0017] This aspect is essentially the same as in the case where the width of the cooling hole's cross-section in the circumferential direction is greater than the width of the cooling hole's cross-section in the axial direction described above. Therefore, this aspect can reduce the stress concentration near the inner opening of the cooling hole and improve the durability of the rotor disk.
[0018] In the case of the rotor disk according to this aspect, where the width of the inner opening of the cooling hole in the circumferential direction is greater than the width of the inner opening in the axial direction, the width of an outer opening, which is an opening of the cooling hole on the radial outer surface, can be greater in the circumferential direction than the width of the outer opening in the axial direction.
[0019] Therefore, this aspect can reduce the stress concentration near the outer opening of the cooling hole and improve the durability of the rotor disk.
[0020] In the case of the rotor disk according to one of the above aspects, the position of an opening of the cooling hole on the radial outer surface in the circumferential direction can be in an area in the circumferential direction where a groove bottom surface of the blade root groove is present.
[0021] In the case of the rotor disk according to one of the above aspects, an area of the radial inner surface around an opening of the hole of the hole group on the radial inner surface can be perpendicular to a direction in which the hole extends on a virtual plane that contains the axis and the hole.
[0022] It is assumed that the region of the radial inner surface around the opening of the hole is an inclined surface (region inner surface) that is tilted with respect to the direction in which the hole extends on the virtual plane including the axis and the hole. In this case, an angle at any corner between a generatrix on an axial downstream side of a columnar hole and the inclined surface is an obtuse angle, and an angle at any corner between a generatrix on an axial upstream side of the columnar hole and the inclined surface is an acute angle. For this reason, stress is concentrated at an edge of the inner opening on the axial upstream side.In this aspect, both the angle at the corner between the generatrix on the axial downstream side of the columnar hole and the inner surface of the area, and the angle at the corner between the generatrix on the axial upstream side of the columnar hole and the inner surface of the area, are 90°, thus preventing the concentration of voltage at the edge of the inner opening on the axial upstream side.
[0023] According to one aspect of the invention, in order to achieve the above objective, a rotor shaft is provided which includes: several rotor disks according to one of the above aspects; and a spindle bolt which penetrates the several rotor disks in the axial direction in order to connect the several rotor disks together, wherein the rotor disks are arranged in the axial direction.
[0024] According to one aspect of the invention, in order to achieve the above objective, a turbine rotor is provided which includes: the rotor shaft according to this aspect; and a rotor blade which is fitted in the blade root groove of each of the several rotor disks.
[0025] According to one aspect of the invention, in order to achieve the above objective, a gas turbine is provided which includes: the turbine rotor according to this aspect; and a turbine casing that covers an outer circumference of the turbine rotor. Advantageous effects of the invention
[0026] According to one aspect of the present invention, the stress concentration near the opening of the cooling hole can be reduced and the durability of the rotor disk can be improved. List of characters Fig. Figure 1 is a schematic view showing a configuration of a gas turbine as an embodiment according to the present invention. Fig. Figure 2 is a sectional view of a main part of a steam turbine as an embodiment according to the present invention. Fig. Figure 3 is a perspective view of a main part of a turbine disk as an embodiment according to the present invention. Fig. Figure 4 is a view of a disk body and a rotor blade as a first embodiment according to the present invention, seen from an axial upstream side. Fig. Figure 5 is a sectional view of the disk body along line VV in Fig. 4. Fig. Figure 6 is a sectional view of a main part of a rotor disk as the first embodiment according to the present invention. Fig. Figure 7 is a view of a disk body as the first embodiment according to the present invention, seen from a radial outside. Fig. Figure 8 is a graph that represents a relationship between a stress concentration factor and a distance between the openings of holes. Fig. Figure 9 is a view of a disk body as a second embodiment according to the present invention, seen from the radial outside. Fig. Figure 10 is a section view along line XX in Fig. 9. Fig. Figure 11 is a sectional view of a main part of a turbine disk as a third embodiment according to the present invention. Fig. Figure 12 is a view of a disk body as the third embodiment according to the present invention, seen from the radial outside. Fig. 13 is a sectional view along line XIII-XIII in Fig. 11. Fig. Figure 14 is a view of a disk body as a first modification example of the third embodiment according to the present invention, seen from the radial outside. Fig. Figure 15 is a view of a disk body as a second modification example of the third embodiment according to the present invention, seen from the radial outside. Fig. Figure 16 is a sectional view of a main part of a rotor disk as a modification example of the first embodiment according to the present invention. Description of embodiments
[0027] Below, an embodiment of a gas turbine which, according to the present invention, includes a rotor disk, and various embodiments are described with reference to the drawings. [Implementation of gas turbine]
[0028] An embodiment of a gas turbine according to the present invention is described with reference to the drawings.
[0029] As in Fig. Figure 1 shows a gas turbine 10 of the present embodiment comprising a compressor 20 that compresses air A; a combustion chamber 30 that burns fuel F in the air A compressed by the compressor 20 to produce combustion gas G; and a turbine 40 that is driven by the combustion gas G.
[0030] The compressor 20 comprises a compressor rotor 21 rotating about an axis Ar; a compressor housing 25 covering the compressor rotor 21; and several stator blade rows 26. The turbine 40 comprises a turbine rotor 41 rotating about the axis Ar, a turbine housing 45 covering the turbine rotor 41; and several stator blade rows 46. Hereinafter, a direction in which the axis Ar extends is referred to as an axial direction Da, a circumferential direction about the rotor axis Ar is simply referred to as a circumferential direction Dc, and a direction perpendicular to the axis Ar is referred to as a radial direction Dr. Furthermore, a side in the axial direction Da is referred to as an axial upstream side Dau, and an opposite side is referred to as an axial downstream side Dad.Furthermore, a side that approaches the axis Ar in the radial direction Dr is called a radial inside Dri, and an opposite side is called a radial outside Dro.
[0031] The gas turbine 10 of the present embodiment further comprises an intermediate housing 16. The compressor 20 is arranged on the axial upstream side Dau with respect to the turbine 40. The intermediate housing 16 is arranged between the compressor housing 25 and the turbine housing 45 in the axial direction Da and connects the compressor housing 25 and the turbine housing 45. The compressor rotor 21 and the turbine rotor 41 are arranged on the same axis Ar and are connected to each other to form a gas turbine rotor 11. For example, a rotor of a generator GEN is connected to the gas turbine rotor 11. Furthermore, the compressor housing 25, the intermediate housing 16, and the turbine housing 45 are connected to each other to form a gas turbine housing 15.
[0032] The compressor rotor 21 includes a rotor shaft 22 extending in the axial direction Da and having the axis Ar as its center, and several rotor blade rows 23 attached to the rotor shaft 22. The multiple rotor blade rows 23 are arranged in the axial direction Da. Each rotor blade row 23 is formed from several rotor blades arranged in the circumferential direction Dc. A stator blade row 26 is arranged on the axial downstream side Dad of each of the multiple rotor blade rows 23. Each of the stator blade rows 26 is provided within the compressor housing 25. Each of the stator blade rows 26 is formed from several stator blades arranged in the circumferential direction Dc.
[0033] The turbine rotor 41 includes a rotor shaft 42, which has a center point in the axial direction Da and the axis Ar, and several rotor blade rows 43 attached to the rotor shaft 42. The multiple rotor blade rows 43 are arranged in the axial direction Da. Each rotor blade row 43 is formed from several rotor blades 44 arranged in the circumferential direction Dc. The stator blade row 46 is arranged on the axial upstream side Dau of each of the multiple rotor blade rows 43. Each stator blade row 46 is provided on the radial inside of the turbine casing 45. Each stator blade row 46 is formed from several stator blades 47 arranged in the circumferential direction Dc.
[0034] As in Fig. As shown in Figure 2, the turbine housing 45 comprises an outer housing 45a, which has a tubular shape and forms an outer shell of the turbine housing 45; an inner housing 45b, which is attached to a radial inner surface of the outer housing 45a; several heat shield rings 45c, which are attached to a radial inner surface of the inner housing 45b; and a ring segment 45d, which is attached to a radial inner surface of each of the several heat shield rings 45c. Each of the several of the ring segments 45d is positioned between the plurality of stator blade rows 46. Therefore, the rotor blade row 43 is arranged on the radial inner surface Dri of each of the ring segments 45d. In addition, the stator blade 47 is also attached to the radial inner surface Dri of each of the several heat shield rings 45c.
[0035] An annular space between an outer circumferential side of the rotor shaft 42 and an inner circumferential side of the turbine housing 45, in which the stator blades 47 and the rotor blades 44 are arranged in the axial direction Da, forms a combustion gas flow path 49 through which the combustion gas G flows from the combustion chamber 30.
[0036] As in Fig. As shown in Figure 1, the gas turbine 10 of the present embodiment is provided with a cooling device 50. The cooling device 50 is a device that cools high-temperature components in contact with the high-temperature combustion gas located beneath the gas turbine components. The cooling device 50 includes a vent line 51 that vents compressed air into the intermediate casing 16; a cooler 52 provided in the vent line 51; a cooling air line 53 that carries the compressed air cooled by the cooler 52 as cooling air to the turbine rotor 41, which is one of the high-temperature components; and an amplifier 54 provided in the cooling air line 53 that amplifies the cooling air. A cooling air flow path 42p is formed in the rotor shaft 42 of the turbine 40. The cooling air flow path 42p extends to several rotor blades 44 that are attached to the rotor shaft 42.
[0037] As in Fig. As shown in Figure 2, the rotor shaft 42 includes several rotor disks 42d arranged in the axial direction Da, and a spindle bolt 42s that penetrates the several rotor disks 42d in the axial direction Da to connect them together. The several rotor blades 44, forming a rotor blade array 43, are attached to a rotor disk 42d. The rotor blade 44 includes a blade body 44b, which has a blade shape; a platform 44f formed on the radial inner surface Dri of the blade body 44b; and a blade root 44r formed on the radial inner surface Dri of the platform 44f. A cooling air channel 44p, through which the cooling air flows, is formed in the rotor blade 44. An inlet opening of the cooling air duct 44p is formed in a bottom surface of the blade root 44r, the bottom surface facing the radial inner side Dri.
[0038] As in Fig. As shown in Figure 1, the compressor 20 compresses the air A to produce compressed air. The compressed air flows from the compressor 20 into the intermediate housing 16. A portion of the compressed air that has flowed into the intermediate housing 16 flows into the combustion chamber 30. The fuel F is supplied to the combustion chamber 30. In the combustion chamber 30, the fuel F is burned in the compressed air to produce the high-temperature and high-pressure combustion gas. The combustion gas G is directed from the combustion chamber 30 into the combustion gas flow path 49 within the turbine 40. The combustion gas G rotates the turbine rotor 41 in the process of flowing through the combustion gas flow path 49 towards the axial downstream side Dad. The rotor of the generator GEN, which is connected to the gas turbine rotor 11, is rotated by the rotation of the turbine rotor 41. As a result, the generator produces electricity.
[0039] The rotor blade 44 or the stator blade 47 of the turbine 40 is exposed to the high-temperature combustion gas G. For this reason, the rotor blade 44 or the stator blade 47 is cooled by a cooling medium. In the present embodiment, the rotor blade 44 is cooled by the cooling air from the cooling device 50. A portion of the compressed air generated by the compressor 20 is released from the intermediate housing 16. The compressed air flows through the vent line 51 into the cooler 52 and is cooled there. The compressed air cooled by the cooler 52 is amplified by the amplifier 54 and then flows as cooling air Ac through the cooling air duct 53 into the cooling air flow path 42p of the rotor shaft 42. The cooling air Ac flows from the cooling air flow path 42p of the rotor shaft 42 into the cooling air channel 44p of the rotor blade 44 to cool the rotor blade 44.
[0040] The rotor disk 42d described above is a rotor disk that can be described in any of the following embodiments and modification examples. [First embodiment of rotor disk]
[0041] Below, a rotor disk of the present embodiment is described with reference to Fig. 2 to Fig. 8 described.
[0042] As in Fig. 2 and Fig. Figure 3 shows that a rotor disk 60 of the present embodiment comprises a disk body 61, a sealing ring 85 and a sealing cap 88.
[0043] The disk body 61 comprises a large-diameter section 62, a small-diameter section 72, and several extension sections 81 and 83. Both the large-diameter section 62 and the small-diameter section 72 have a substantially columnar shape around the axis Ar. The radius of the large-diameter section 62 is larger than the radius of the small-diameter section 72. The small-diameter section 72 is located on the axial upstream side Dau of the large-diameter section 62.The extension sections 81 and 83 include an upstream extension section 81 extending from a surface on the axial upstream side Dau of the small-diameter section 72 to the axial upstream side Dau, and a downstream extension section 83 extending from a surface on the axial downstream side Dad of the large-diameter section 62 to the axial downstream side Dad.
[0044] The large-diameter section 62 includes an outer circumferential surface 63 facing the radial outer side Dro, and several blade root grooves 64 extending from the outer circumferential surface 63 towards the radial inner side Dri. The multiple blade root grooves 64 are arranged at equal intervals in the circumferential direction Dc. The blade root 44r of the rotor blade 44 is positioned in each of the multiple blade root grooves 64.
[0045] As in Fig. 3 to Fig. As shown in Figure 6, the small-diameter section 72 includes an outer circumferential surface 73 facing the radial outer side Dro; a front surface 74 facing the axial upstream side Dau; several communication grooves 75 extending from the outer circumferential surface 73 to the radial outer side Dro; and an annular groove 76 extending from the front surface 74 to the axial downstream side Dad and extending in the circumferential direction Dc with respect to the axis Ar. Each of the several communication grooves 75 is formed at the same position as one of the blade root grooves 64 in the circumferential direction Dc. A distance from the axis Ar to a groove bottom surface 75b of the communication grooves 75 is essentially equal to a distance from the axis Ar to a groove bottom surface 64b of the blade root groove 64. For this reason, each of the multiple communication grooves 75 communicates with a blade root groove 64 of the multiple blade root grooves 64.The annular groove 76 comprises an inner groove side surface 76i facing the radial outer side Dro; an outer groove side surface 76o facing the radial inner side Dri; and a groove bottom surface 76b facing the axial upstream side Dau. The inner groove side surface 76i is located on the radial inner side Dri of the outer groove side surface 76o. Part of the inner groove side surface 76i of the annular groove 76 forms the groove bottom surface 75b of the communication groove 75. For this reason, the annular groove 76 communicates with the multiple communication grooves 75. The entire inner groove side surface 76i of the annular groove 76, the groove bottom surface 75b of the communication groove 75, and the groove bottom surface 74b of the blade root groove 64 are radial outer surfaces facing the radial outer side Dro.
[0046] The small-diameter section 72 further comprises several groups of holes 77 arranged in the circumferential direction Dc. These groups of holes 77 are provided for the multiple blade root grooves 64. Specifically, each group of holes 77 is provided for one blade root groove 64. Each group of holes 77 contains several holes, in the present embodiment two holes, which extend from a radial inner surface 82 of the upstream extension section 81 to the radial outer surface Dro. The radial inner surface 82 of the upstream extension section 81 is located on the radial inner surface Dri of the radial outer surfaces 76i, 75b, and 64b of the small-diameter section 72.In the present embodiment, several holes form cooling holes 78, which extend from the radial inner surface 82 of the upstream extension section 81 to the radial outer surface, which is the groove bottom surface 75b of the communication groove 75 (inner groove side surface 76i of the annular groove 76). Two cooling holes 78 are open in the groove bottom surface 75b of a communication groove 75. Hereinafter, the opening is referred to as an outer opening 78o. As described above, the communication groove 75 communicates with the blade root groove 64. Therefore, the cooling hole 78 communicates with a space in the blade root groove 64 through a space in the communication groove 75. The cross-sectional shape of the cooling hole 78 is a circle. The cross-section referred to here is a plane extending in a direction perpendicular to the direction in which the cooling hole 78 extends. Several cooling holes 78 are arranged in the circumferential direction Dc.
[0047] The radial inner surface Dri of the upstream extension section 81 serves as a cooling air space (see Fig. 2), into which the cooling air from the cooling device 50 flows. Therefore, the cooling air that has flowed into the cooling air space flows through the cooling hole 78 and the space in the communication groove 75 into the blade root groove 64. The cooling air that has flowed into the space in the blade root groove 64 flows into the cooling air channel 44p of the rotor blade 44. Therefore, in the present embodiment, the cooling air flow path 42p of the rotor shaft 42, which with reference to Fig. 2 described, the cooling air space, the cooling hole 78, the space in the communication groove 75 and the space in the blade foot groove 64.
[0048] The sealing ring 85 comprises an annular section 86 extending in the circumferential direction Dc and several separating sections 87. The annular section 86 closes part of an opening in the circumferential direction Dc of the annular groove 76. The separating section 87 projects from a surface on the axial downstream side Dad of the annular section 86 to the axial downstream side Dad in order to divide the interior of the annular groove 76 in the circumferential direction Dc.
[0049] As in Fig. 3 and Fig. As shown in Figure 6, the sealing cap 88 closes an opening of the communication groove 75. The sealing cap 88 is in contact with the sealing ring 85 and the paddle foot 44r to fill a gap between them.
[0050] As in Fig. 3 and Fig. As shown in Figure 7, the outer opening 78o of the cooling hole 78 is located in the circumferential direction Dc within a region Rb in the circumferential direction Dc, where the groove bottom surface 64b of the blade root groove 64 is present. In the circumferential direction Dc, each of the multiple separating pieces 87 of the sealing ring 85 is located between region Rb and the region Rb in the circumferential direction Dc where the groove bottom surface 64b of another blade root groove 64, adjacent to the blade root groove 64, is present. Therefore, a space in the annular groove 76 is subdivided by the separating piece 87 in the circumferential direction Dc into a space of a section in which one blade root groove 64 is present and a space of a section in which another blade root groove 64, adjacent to the blade root groove 64 in the circumferential direction Dc, is present.
[0051] A circumferential group width dcg, which is the width of each of the multiple hole groups 77 in the circumferential direction Dc, is larger than an axial group width dga, which is the width of each of the multiple hole groups 77 in the axial direction, and is smaller than a minimum group spacing dg of group spacings, each of which is a distance between the multiple hole groups 77 in the circumferential direction Dc. The axial group width dga corresponds to the diameter of the circular outer opening 78o of the cooling hole 78. The circumferential group widths dgc, each of which is the width of each of the multiple hole groups 77 in the circumferential direction Dc, are equal to each other. The group spacing dg between two hole groups 77 that are adjacent to each other in the circumferential direction Dc is the same as the group spacing dg between two other hole groups 77 that are adjacent to each other in the circumferential direction Dc. In other words, the group spacings dg are equal to each other.Therefore, in the present embodiment, each of the group spacings dg is also the minimum group spacing dg. A hole spacing dh, which is a distance in the circumferential direction Dc between two cooling holes 78 forming a hole group 77, is a dimension obtained by subtracting twice the diameter (= dga) of the cooling hole 78 from the circumferential group width dgc (= dgc - 2·dga). Therefore, the order of magnitude between the dimensions is as follows. dg > dgc > (dga, dh)
[0052] The size ratio between dga and dh is irrelevant.
[0053] The size ratio between the dimensions described above is a size ratio in the radial outer surface 76i, in which the outer opening 78o of the cooling hole 78 is formed. In the present embodiment, however, a size ratio between the dimensions in the radial inner surface 82, in which an inner opening 78i of the cooling hole 78 is formed, and a size ratio between the dimensions at a position between the radial outer surface 76i and the radial inner surface 82 are the same as the size ratio between the dimensions in the radial outer surface 76i.
[0054] As in Fig. As shown in Figure 8, the stress concentration factor decreases when the distance between the openings of the two holes is reduced. This is because stress generated around the opening of one hole is distributed around the opening of the adjacent hole. The stress concentration factor is a value obtained by dividing the maximum stress σmax generated in an element by the average stress σave generated in that element (= σmax / σave).
[0055] In the present embodiment, as described above, the circumferential group width dgc is smaller than the minimum group spacing dg. Therefore, the hole spacing dh between two cooling holes 78 forming a hole group 77 is smaller than the minimum group spacing dg. For this reason, in the present embodiment, the hole spacing dh between two cooling holes 78 forming a hole group 77 is smaller than if all cooling holes 78 formed in the small-diameter section 72 were arranged at equal intervals in the circumferential direction Dc. Therefore, in the present embodiment, the stress concentration near the opening of the cooling hole 78 can be reduced, and the durability of the rotor disk 60 can be improved. [Second embodiment of rotor disk]
[0056] Below, a rotor disk of the present embodiment is described with reference to Fig. 9 to Fig. 10 described.
[0057] A rotor disk 60a of the present embodiment has a different configuration of several hole groups than the rotor disk 60 of the first embodiment, and essentially has the same other configurations as those of the rotor disk 60 of the first embodiment. Therefore, several hole groups in the rotor disk 60a of the present embodiment are mainly described below.
[0058] As in Fig. As shown in Figure 9, in the present embodiment each of the several hole groups 77a contains three holes that extend from a radial inner surface 82 of the upstream extension section 81 to a radial outer surface Dro. Two of the three holes form the cooling hole 78, which extends from the radial inner surface 82 of the upstream extension section 81 to the radial outer surface, which is the groove bottom surface 75b of the communication groove 75 (inner groove side surface 76i of the annular groove 76). Similarly, a remaining hole 79 extends from the radial inner surface 82 of the upstream extension section 81 to the radial outer surface, which is the inner groove side surface 76i of the annular groove 76. The hole 79 further extends from the outer groove side surface 76o of the annular groove 76 to the outer circumferential surface 73 of the small-diameter section 72. Hole 79 is a dummy hole that does not function as a hole through which cooling air (Ac) flows. As shown in... Fig. As shown in Figure 10, an opening of the dummy hole 79 in the outer circumferential surface 73 of the section 72 with a small diameter is closed with a plug 89.
[0059] Similar to the cooling hole 78 of the first embodiment, the position of the outer opening 78o of the cooling hole 78 in the circumferential direction Dc lies in the region Rb in the circumferential direction Dc where the groove bottom surface 64b of the blade root groove 64 is located. The position of an outer opening 79o of the dummy hole 79 (radial outer surface) of the annular groove 76 in the inner groove side surface 76i in the circumferential direction Dc is displaced from the region Rb in the circumferential direction Dc where the groove bottom surface 64b of the blade root groove 64 is located. A separating element 87 of the several separating elements 87 of the sealing ring 85 is located between the cooling hole 78 of two cooling holes 78 of a hole group 77a and the dummy hole 79 in the circumferential direction Dc, with the cooling hole 78 being closest to the dummy hole 79 of the hole group 77a. Furthermore, the other separating piece 87 is located between the hole group 77a and another hole group 77a, which is adjacent to the hole group 77a in the circumferential direction Dc.For this reason, the space in the annular groove 76 is divided by the separating piece 87 in the circumferential direction Dc into a space of a section in which the blade root groove 64 is present (section in which the outer openings 78o of two cooling holes 78 are present) and a space of a section in which the blade root groove 64 is not present. Therefore, the dummy hole 79 and the interior of the blade root groove 64 do not communicate with each other. For this reason, even if the cooling air Ac flows into the dummy hole 79, it is unable to flow through the blade root groove 64 into the cooling air channel 44p of the rotor blade 44.
[0060] Similar to the first embodiment, the circumferential group width dgc of each of the multiple hole groups 77a is larger than the axial group width dga of each of the multiple hole groups 77a and is smaller than a minimum group spacing dg1 between the multiple hole groups 77a. The axial group width dga corresponds to the diameter of the circular outer opening 78o of the cooling hole 78. In the present embodiment, the circumferential group widths dgc of the multiple hole groups 77a are also equal to each other. A group spacing dg1 between two hole groups 77a that are adjacent to each other in the circumferential direction Dc is the same as the group spacing dg1 between two other hole groups 77 that are adjacent to each other in the circumferential direction Dc. The group spacings dg1 are, in fact, equal to each other. Therefore, in the present embodiment, each of the group spacings dg1 is also the minimum group spacing dg1.The hole spacing between two cooling holes 78 of a hole group 77a in the circumferential direction Dc is a first hole spacing dh1. Furthermore, the hole spacing between the cooling hole 78 of two cooling holes 78 of a hole group 77a, wherein the cooling hole 78 is closest to the dummy hole 79 of the hole group 77a, and the dummy hole 79 in the circumferential direction Dc is a second hole spacing dh2. One of the first hole spacings dh1 and the second hole spacing dh2 is a maximum hole spacing and the other is a minimum hole spacing. dg 1 > dgc > (dga, dh1, dh2)
[0061] The size ratio between dga, dh1 and dh2 is irrelevant.
[0062] The size ratio between the dimensions described above is a size ratio in the radial outer surface 76i, in which the outer opening 78o of the cooling hole 78 and the outer opening 78o of the dummy hole 79 are formed. In the present embodiment, however, a size ratio between the dimensions in the radial inner surface 82, in which the inner opening 78i of the cooling hole 78 and the inner opening 78i of the dummy hole 79 are formed, and a size ratio between the dimensions at a position between the radial outer surface 76i and the radial inner surface 82 is the same as the size ratio between the dimensions in the radial outer surface 76i.
[0063] In the present embodiment, as described above, the circumferential group width dgc is smaller than the minimum group spacing dg1. Therefore, the hole spacings dh1 and dh2 between three holes forming a hole group 77a are smaller than the minimum group spacing dg1. Consequently, in the present embodiment, the stress concentration near the opening of the cooling hole 78 can be reduced, and the durability of the rotor disk 60a can be improved. Since, in the present embodiment, the number of holes forming the hole group 77a is greater than the number of holes forming the hole group 77 of the first embodiment, the stress concentration near the opening of the cooling hole 78 can be reduced even more than in the first embodiment.
[0064] The hole group 77a of the present embodiment and the hole group 77 of the first embodiment contain two cooling holes 78; however, if the flow rate of the cooling air required and sufficient to cool the rotor blade 44 is achieved with one cooling hole 78, one of the two dummy holes 78 can function as a dummy hole 79. Furthermore, the hole group 77a of the present embodiment contains one of three holes as the dummy hole 79, but all three holes can function as the cooling holes 78. Additionally, the hole group 77a of the present embodiment contains three holes, but can also contain four or more holes. In this case, at least one of the four or more holes must be the cooling hole 78.
[0065] The tensile stress described above, which is generated in the rotor disk 60a, is greater in the radial inner surface 82 than in the radial outer surface 76i of the small-diameter section 72. Therefore, the stress generated around the inner opening 78i of the cooling hole 78 is also greater than the stress generated around the outer opening 78o of the cooling hole 78. Consequently, all of the multiple holes of the hole group 77a in the radial inner surface 82 of the small-diameter section 72 must be open. Conversely, not all of the multiple holes of the hole group 77a in the radial outer surface 76i of the small-diameter section 72 need to be open. Therefore, the dummy hole 79, which is one of the multiple holes of the hole group 77a, does not need to be open in the radial outer surface 76i of the small-diameter section 72. [Third embodiment of rotor disk]
[0066] Below, a rotor disk of the present embodiment is described with reference to Fig. 11 to Fig. 13 described.
[0067] A rotor disk 60b of the present embodiment has a different configuration of several hole groups than the rotor disk 60 of the first embodiment and has essentially the same other configurations as those of the rotor disk 60 of the first embodiment. Therefore, several hole groups 77b in the rotor disk 60b of the present embodiment are mainly described below.
[0068] As in Fig. 11 to Fig. As shown in Figure 13, in the present embodiment each of the several hole groups 77b contains a hole that extends from the radial inner surface 82 of the upstream extension section 81 to a radial outer surface. The hole forms a cooling hole 78b that penetrates from the radial inner surface 82 of the upstream extension section 81 to the radial outer surface, which is the groove bottom surface 75b of the communication groove 75 (inner groove side surface 76i of the annular groove 76). The cooling hole 78b has an oval cross-sectional shape in a plane perpendicular to the radial direction Dr in which the cooling hole 78b extends. Therefore, the shape of the inner opening 78o of the cooling hole 78b is also an oval, as shown in Figure 13. Fig. 13 shown, and the shape of the outer opening 78i of the cooling hole 78b is also an oval, as in Fig. Figure 12 illustrates the oval shape, which is a raceway shape formed by two opposing semicircles separated by a gap and connected by two parallel straight lines. In the present embodiment, the longitudinal direction of the oval is the circumferential direction Dc. Therefore, the circumferential opening width dhc, which is the width of the inner opening 78i of the cooling hole 78b in the circumferential direction Dc, is greater than the axial opening width dha, which is the width of the inner opening 78i in the axial direction Da. Furthermore, the circumferential opening width dhc, which is the width of the outer opening 78o of the cooling hole 78b in the circumferential direction Dc, is greater than the axial opening width dha, which is the width of the outer opening 78i in the axial direction Da.
[0069] Similar to the cooling hole 78 of the first embodiment, the position of the outer opening 78o of the cooling hole 64 in the circumferential direction Dc lies in the region Rb in the circumferential direction Dc where the groove bottom surface 78b of the blade root groove 64 is located. In the circumferential direction Dc, each of the several separating pieces 87 of the sealing ring 85 is located between the region Rb and the region Rb in the circumferential direction Dc where the groove bottom surface 64b of another blade root groove 64, adjacent to the blade root groove 64, is located. For this reason, a space in the annular groove 76 is divided by the separating piece 87 in the circumferential direction Dc into a space of a section in which a blade root groove 64 is located and a space of a section in which another blade root groove 64, adjacent to the blade root groove 64 in the circumferential direction Dc, is located.
[0070] The circumferential group width dgc of each of the multiple hole groups 77b is equal to the circumferential opening width dhc of the cooling holes 78b. The circumferential group width dcg and the circumferential opening width dhc are larger than the axial group width dga of each of the multiple hole groups 77b and are smaller than a minimum group spacing dg2 of group spacings, each of which is a distance between the multiple hole groups 77 in the circumferential direction Dc. The axial group width dga is equal to the axial opening width dha of the cooling hole 78b. The circumferential group widths dgc of the multiple hole groups 77b are equal to each other. A group spacing dg2 between two hole groups 77a that are adjacent to each other in the circumferential direction Dc is the same as the group spacing dg2 between two other hole groups 77b that are adjacent to each other in the circumferential direction Dc. The group spacings dg2 are, in fact, equal to each other.Therefore, in the present embodiment, each of the group spacings dg2 is also the minimum group spacing dg2. An order of magnitude between the dimensions is as follows. dg2 > dgc = dhc > dga = dha
[0071] The size ratio between the dimensions described above is a size ratio in the radial outer surface 75b, in which the outer opening 78o of the cooling hole 78 is formed. In the present embodiment, however, a size ratio between the dimensions in the radial inner surface 82, in which the inner opening 78i of the cooling hole 78b is formed, and a size ratio between the dimensions at a position between the radial outer surface 75b and the radial inner surface 82 are the same as the size ratio between the dimensions in the radial outer surface 75b.
[0072] In the present embodiment, the outer opening 78o and the inner opening 78i of the cooling hole 78b have a shape in which the openings of two holes are connected to each other in the circumferential direction Dc. For this reason, in the present embodiment, stresses generated around the outer opening 78o of the cooling hole 78b and stresses generated around the inner opening 78i are distributed in the circumferential direction Dc. Therefore, in the present embodiment, the stress concentration near the opening of the cooling hole 78b can be reduced, and the durability of the rotor disk 60b can be improved.
[0073] In the cooling hole 78b of the present embodiment, both the shape of the inner opening 78i and the shape of the outer opening 78o are oval. As described above, the stress generated around the inner opening 78i of the cooling hole 78b is greater than the stress generated around the outer opening 78o of the cooling hole 78b. For this reason, the shape of the inner opening 78i of the cooling hole 78b can be oval, and the shape of the outer opening 78o of the cooling hole 78b can be circular. Furthermore, the shape of the opening of the cooling hole 78b need not be oval with a circumferential length Dc, as long as the circumferential opening width dhc of the cooling hole 78b is greater than the axial opening width dha. In particular, as shown in Fig. Figure 14 shows that the shape of an opening of a cooling hole 78c can be a shape in which two circles partially overlap each other in the circumferential direction Dc. Furthermore, as shown in Fig. Figure 15 shows the shape of an opening of a cooling hole 78d to be an elliptical shape, which is long in the circumferential direction Dc.
[0074] Furthermore, similar to the second embodiment, the hole group 77b of the present embodiment can also include the dummy hole 79 in addition to the cooling hole 78b. [Various modification examples]
[0075] The rotor discs of the first and third embodiments include the annular groove 76. However, the rotor discs of the first and third embodiments need not include the annular groove 76. If no annular groove 76 is provided, the sealing ring 85, which closes the opening of the annular groove 76, is not required.
[0076] In each of the embodiments described above, the multiple hole groups are arranged at equal intervals in the circumferential direction Dc. However, the multiple hole groups can be arranged in the circumferential direction Dc, but not necessarily at equal intervals.
[0077] In each of the embodiments described above, a region around the inner opening of the hole on the radial inner surface 82 is inclined in a direction in which the hole extends on a virtual plane containing the axis Ar and the hole, namely in the radial direction. In other words, as in Fig. As shown in Figure 6 and the like, the area around the inner opening on the radial inner surface 82 is an inclined surface that gradually approaches the radial inner surface Dri towards the axial downstream side Dad. In this case, an angle Θd at a corner between a generatrix on the axial downstream side Dad of the columnar hole and the inclined surface is an obtuse angle, and an angle Θu at a corner between a generatrix on the axial upstream side of the columnar hole and the inclined surface is an acute angle. For this reason, stress is concentrated at an edge of the inner opening on the axial upstream side Dau. Therefore, as shown in Fig.As shown in Figure 16, preferably an inner region surface 82a around the inner opening of the hole is located on the radial inner surface 82 perpendicular to the direction in which the hole extends on the virtual plane containing the axis Ar and the hole. In this way, both the angle at the corner between the generatrix on the axial downstream side Dad of the columnar hole and the inner region surface 82a and the angle at the corner between the generatrix on the axial upstream side Dau of the columnar hole and the inner region surface 82a are 90°, thus preventing stress concentration at the edge of the inner opening 78i on the axial upstream side.
[0078] In each of the embodiments described above, the direction in which the hole extends is radially perpendicular to the axis Ar. However, the direction in which the hole extends can gradually be inclined towards the axial downstream side Dad and the radial outside Dro. If the direction in which the hole extends is inclined in such a manner as described above, the direction in which the hole extends can be made perpendicular to the inclined surface, even if the area around the inner opening 78i on the radial inner surface 82 is an inclined surface that gradually approaches the radial inside Dri towards the axial downstream side Dad. Furthermore, if the direction in which the hole extends is inclined in such a manner, the cooling hole 78b is able to communicate directly with the space in the blade root groove 64 without having to pass through the space in the communication groove 75. Industrial applicability
[0079] According to one aspect of the present invention, the stress concentration near the opening of the cooling hole can be reduced and the durability of the rotor disk can be improved. Reference symbol list 10 Gas turbine 11 Gas turbine rotor 15 gas turbine casings 16 intermediate housings 20 Compressor 21 Compressor rotor 22 Rotor shaft 23 rotor blade rows 25 Compressor housings 26 stator blade row 30 combustion chamber 40 Turbine 41 Turbine rotor 42 Rotor shaft 42p Cooling air flow path 42d, 60, 60a, 60b rotor disk 42s Spindle bolt 43 rotor blade rows 44 Rotor blade 44b Blade body 44f platform 44r Shovel foot 44p cooling air duct 45 turbine housings 45a Outdoor housing 45b Inner housing 45c heat shield ring 45d ring segment 46 stator blade row 47 Stator blade 49 Combustion gas flow path 50 Cooling device 51 Vent line 52 coolers 53 Cooling air duct 54 amplifiers 61 disc bodies 62 Large diameter section 63 Outer circumferential area (or radial outer surface) 64 Shovel foot groove 64b Groove bottom surface (or radial outer surface) 72 Small diameter section 73 External perimeter area 74 Front surface 75 Communication skills 75b Groove bottom surface (or radial outer surface) 76 Ring groove 76i Inner groove side surface (or radial outer surface) 76° Outer groove side surface 76b Grooved floor area 77, 77a, 77b Hole group 78, 78b, 78c, 78d Cooling hole 78i Inner Opening 78° Outer opening 79 Dummy Hole 81 upstream extension section 82 Radial inner surface 82a Area interior 83 downstream extension section 85 Sealing ring 86 ring pieces 87 Separator 88 Sealing cap 89 plugs A air AC cooling air Fuel G Combustion gas dh hole spacing dhc circumferential opening width dha Axial opening width dgc circumference group width dga Axial group width dg minimum group distance Ar axis Since axial direction Dau axial upstream side Dad axial downstream side DC circumferential direction Dr. Radial direction Three radial inner sides Dro radial outer side QUOTES INCLUDED IN THE DESCRIPTION
[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature
[0000] JP 2019097549
[0002]
Claims
[1] Rotor disk, comprising: a radial outer surface facing a radial outside that is one side away from an axis in a radial direction with respect to the axis; a radial inner surface which faces a radial inside which is a side opposite the radial outside in the radial direction, and which is located on the radial inside of the radial outer surface; several blade root grooves, recessed from the radial outer surface to the radial inner surface and arranged in a circumferential direction with respect to the axis; and several groups of holes formed for the multiple blade foot grooves and arranged in the circumferential direction, wherein each of the multiple hole groups contains holes that include a cooling hole penetrating from the radial inner surface to the radial outer surface, a width of each of the multiple hole groups in the circumferential direction is greater than a width of each of the multiple hole groups in an axial direction in which the axis extends, and is less than a minimum distance of the distances between the multiple hole groups in the circumferential direction, and the cooling hole communicates with an inside of the blade root groove. [2] Rotor disk according to claim 1, wherein each of the multiple hole groups contains multiple holes which are recessed from the radial inner surface to the radial outer surface and arranged in the circumferential direction, and at least one of the multiple holes is the cooling hole. [3] Rotor disk according to claim 2, wherein a maximum hole spacing of distances between the multiple holes of the hole group in the circumferential direction is smaller than the minimum distance of the distances between the multiple hole groups in the circumferential direction. [4] Rotor disk according to claim 2 or 3, wherein all of the multiple holes of the hole group are the cooling holes. [5] Rotor disk according to claim 1, wherein a width of an inner opening, which is an opening of the cooling hole on the radial inner surface, is greater in the circumferential direction than a width of the inner opening in the axial direction. [6] Rotor disk according to claim 5, wherein a width of an outer opening, which is an opening of the cooling hole on the radial outer surface, is greater in the circumferential direction than a width of the outer opening in the axial direction. [7] Rotor disk according to one of claims 1 to 6, wherein a position of an opening of the cooling hole on the radial outer surface in the circumferential direction is located in a region in the circumferential direction in which a groove bottom surface of the blade root groove is present. [8] Rotor disk according to one of claims 1 to 7, wherein a region of the radial inner surface around an opening of the hole of the hole group on the radial inner surface is perpendicular to a direction in which the hole extends on a virtual plane containing the axis and the hole. [9] Rotor shaft, comprising: several of the rotor disks according to one of claims 1 to 8; and a spindle bolt that penetrates the multiple rotor disks in the axial direction to connect the multiple rotor disks together, the rotor disks being arranged in the axial direction. [10] Turbine rotor, comprising: the rotor shaft according to claim 9; and a rotor blade that is mounted in the blade root groove of each of the multiple rotor disks. [11] Gas turbine, comprising: the turbine rotor according to claim 10; and a turbine housing that covers the outer circumference of the turbine rotor.