JP6125407B2 - Stator blade, steam turbine, and stator blade manufacturing method - Google Patents

Description

  The present invention relates to a stationary blade, a steam turbine, and a method for manufacturing a stationary blade.

  In order to reduce the weight of a stationary blade of a steam turbine, a hollow stationary blade having a hollow inside is known. In addition, in order to improve the performance of the stationary blade, there is a technology to provide a slit that connects the cavity (internal space) of the stationary blade and the external space, and to remove water droplets adhering to the outer surface of the stationary blade. Are known. Furthermore, in order to increase the efficiency and cost of the stationary blade, the size of the stationary blade in the radial direction with respect to the rotation axis of the rotor of the steam turbine is increased, and the size of the stationary blade in the direction parallel to the rotation axis is increased. Increasing the aspect ratio to make it smaller.

  Self-excited vibration (flutter) occurs in the stator blades due to the outer shape of the stator blades, the mass of the stator blades, and the environment around the stator blades during steam turbine operation (for example, the flow velocity and flow rate of steam passing through the stator blades). there's a possibility that. The hollow stationary blade is lighter than a solid stationary blade having no cavity. Therefore, the possibility that self-excited vibration is generated in the hollow stationary blade is higher than that in the solid stationary blade. Also, the possibility of self-excited vibration increases when the size of the stationary blade in the radial direction with respect to the rotation axis of the rotor is large. In particular, since the size of the stationary blade increases as the pressure reaches the lower final stage, the possibility that self-excited vibration occurs in the stationary blade at the lower pressure final stage increases. Therefore, for example, as disclosed in Patent Document 1, a damper member (sliding contact member, leaf spring member) is provided in the hollow portion of the hollow stationary blade to suppress the occurrence of self-excited vibration in the hollow stationary blade. Technology has been devised.

JP 2008-133825 A

  In the stationary blade disclosed in Patent Document 1, even if the damper member is designed so that the self-excited vibration is suppressed, the self-excited vibration is not obtained if the manufactured stationary blade cannot obtain the vibration characteristics that meet the requirements. May not be sufficiently suppressed. Further, if the manufactured stationary blade cannot obtain the vibration characteristics that meet the requirements, for example, the damper member must be remanufactured, increasing costs and labor.

  It is an object of the present invention to provide a stationary blade, a steam turbine, and a method for manufacturing a stationary blade that can obtain vibration characteristics that meet the requirements.

  A stationary blade according to the present invention is a stationary blade used in a steam turbine, and is connected to the ventral member and the ventral member at each of a front edge portion and a rear edge portion, and between the ventral member. A back side member provided with a cavity, and a first inner surface of the abdominal member facing the cavity and a second inner surface of the back member facing the cavity are fixed to the inner surface. A damper member having a fixed portion and a contact portion that is relatively movable in contact with the other inner surface; and an additional member that is fixed to at least a part of the damper member and adjusts the rigidity of the damper member. .

  According to the present invention, by providing the damper member in the cavity, when the stationary blade is elastically deformed, the damper moves relative to the contact portion of the damper member and the other inner surface, and the contact portion and the other inner surface Friction occurs between them. Since the elastic deformation of the stationary blade is suppressed by the friction, the occurrence of self-excited vibration in the stationary blade is suppressed. For example, the relative positional fluctuation between the ventral member and the dorsal member is suppressed by the friction. As a result, the occurrence of self-excited vibration in the stationary blade is suppressed. Also, by fixing the additional member to the damper member and adjusting the rigidity of the damper member, the vibration reduction effect by the damper member can be adjusted with a simple configuration and technique, and the stationary blade has the vibration characteristics that meet the requirements. Can be obtained. Therefore, the occurrence of self-excited vibration in the stationary blade is suppressed, and damage to the stationary blade can be prevented.

  In the stator blade according to the present invention, the damper member may be elastically deformed, and may apply an outward force to the first inner surface and the second inner surface with respect to the cavity. When the damper member urges each of the abdominal member and the dorsal member toward the outside, when a relative position change occurs between the abdominal member and the dorsal member, the damper member is forced to the urging force. A corresponding dynamic friction force can be generated between at least one of the ventral member and the dorsal member. By adjusting the rigidity of the damper member with the additional member, or adjusting the biasing force of the damper member in the state of being placed in the cavity (initial state), the position variation between the abdominal member and the back member can be changed. Can be suppressed.

  In the stator blade according to the present invention, the damper member may have an intermediate part between the fixing part and the contact part, and the additional member may be fixed to at least a part of the surface of the intermediate part. . By fixing the additional member to the middle part of the damper member, the rigidity of the damper member can be effectively increased.

  In the stator blade according to the present invention, the damper member has a facing surface facing the other inner surface, and a back surface facing the opposite direction of the facing surface, and the additional member is fixed to the back surface. Good. Thereby, the rigidity of a damper member can be adjusted, without preventing the relative movement of the opposing surface of the contact part of a damper member, and the other inner surface.

  In the stationary blade according to the present invention, the additional member may be fixed to a central portion of the damper member at least in a radial direction with respect to a rotation axis of a rotor shaft of the steam turbine. The stationary blade is fixed at both ends with respect to the radial direction. When vibration occurs in the stationary blade, there is a high possibility that the amplitude of the central portion of the stationary blade increases in the radial direction. Therefore, at least the vibration of the stationary blade can be effectively suppressed by fixing the additional member to the central portion of the damper member that becomes the vibration antinode.

  In the stationary blade according to the present invention, the contact portion may be arranged on each of the front edge portion side and the rear edge portion side of the fixed portion. As a result, the contact between the contact portion and the other inner surface is stabilized, and even when vibration is significantly generated in either the front edge portion or the rear edge portion, the vibration can be effectively damped.

  In the stationary blade according to the present invention, an area of the contact portion that contacts the other inner surface may be larger than an area of the fixed portion fixed to the one inner surface. Since the contact area of the contact part with respect to the other inner surface is large, the vibration reduction effect by the damper member can be enhanced.

  A steam turbine according to the present invention includes a rotor shaft and the above-described stationary blades arranged in the circumferential direction of the rotor shaft.

  According to the present invention, by having a stationary blade in which self-excited vibration is suppressed, a decrease in performance of the steam turbine is suppressed.

  A stator blade manufacturing method according to the present invention is a stator blade manufacturing method used for a steam turbine, wherein the stator blade is a back capable of forming a cavity portion between a ventral member and the ventral member. A step of designing the damper member to obtain a desired damping effect, and a plate-like member based on the design. The damper member is manufactured by pressing, and the base of the damper member is fixed to one inner surface of the first inner surface of the ventral member and the second inner surface of the back member, and the other inner surface Connecting the abdominal member and the dorsal member at each of the front edge portion and the rear edge portion with the end portion of the damper member in contact with each other, and disposing the damper member in the cavity portion And obtain vibration characteristics of the stationary blade by performing a vibration test of the stationary blade. That a step, based on the vibration test results, by adding an additional member to at least a portion of the damper member, and a step of adjusting the rigidity of the damper member.

  According to the present invention, a stationary blade including a damper member is designed and manufactured so that self-excited vibration is suppressed, and the vibration test is performed even if the stationary blade after the manufacturing cannot obtain the required vibration characteristics. By adding an additional member to the damper member based on the result of the above, it is possible to manufacture a stationary blade having vibration characteristics suitable for the demand without remanufacturing the damper member. Therefore, it is possible to manufacture a stationary blade having vibration characteristics meeting demands while suppressing costs and labor.

  According to the stationary blade according to the present invention, vibration characteristics suitable for the requirements can be obtained, so that a decrease in performance is suppressed. Moreover, according to the steam turbine which concerns on this invention, the fall of a performance is suppressed.

FIG. 1 is a schematic configuration diagram illustrating an example of a steam turbine system according to the present embodiment. FIG. 2 is an external view of the steam turbine according to the present embodiment as viewed from the low-pressure final stage side. FIG. 3 is an enlarged view of the stationary blade according to the present embodiment as viewed from the back side. FIG. 4 is a cross-sectional view showing an example of a stationary blade according to the present embodiment. FIG. 5 is a view of the stationary blade according to the present embodiment as viewed from the ventral side. FIG. 6 is a cross-sectional view illustrating an example of the damper member and the additional member according to the present embodiment. FIG. 7 is a perspective view showing a part of the damper member and the additional member according to the present embodiment. FIG. 8 is a view of the damper member according to the present embodiment as viewed from the facing surface and the facing surface side. FIG. 9 is a diagram illustrating an example of the additional member disposed on the damper member according to the present embodiment. FIG. 10 is a flowchart illustrating an example of a method for manufacturing a stationary blade according to the present embodiment.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. In addition, this invention is not limited by this embodiment. In addition, the constituent elements in the embodiments described below can be combined as appropriate. Some components may not be used.

  A steam turbine system 1 according to the present embodiment will be described. FIG. 1 is a schematic configuration diagram illustrating an example of a steam turbine system 1 according to the present embodiment. The steam turbine system 1 is used in, for example, a nuclear power plant. The steam turbine system 1 includes a steam generator 2 that generates high-pressure steam, a high-pressure steam turbine 3 to which high-pressure steam from the steam generator 2 is directly supplied, and steam from the steam generator 2 and the high-pressure steam turbine 3. A moisture separation heater 4 that separates and heats the moisture and a low-pressure steam turbine 5 to which low-pressure steam from the moisture separation heater 4 is supplied. In the present embodiment, the low-pressure steam turbine 5 in the steam turbine system 1 will be mainly described. In the following description, the low-pressure steam turbine 5 is appropriately referred to as a steam turbine 5.

  The steam turbine 5 is provided in the casing (casing) 6, the casing 6, the steam inlet 7 to which the steam from the moisture separation heater 4 is supplied, and provided in the casing 6, from the steam inlet 7. A steam passage 8 through which steam flows, a plurality of moving blades 9 disposed in the steam passage 8, a plurality of stationary blades 10 disposed in the steam passage 8, and a rotor shaft 11 connected to the moving blade 9 are provided. Yes. At least a part of the stationary blade 10 is fixed to the passenger compartment 6. The rotor shaft 11 is rotatably supported by bearings disposed at both ends of the vehicle interior 6. The rotor shaft 11 rotates about an axis (rotating shaft) AX.

  In the steam turbine 5, the steam supplied from the moisture separation heater 4 to the steam inlet 7 flows through the steam passage 8. In the steam passage 8, the moving blades 9 and the stationary blades 10 are alternately arranged with respect to a direction A parallel to the axis AX. The stationary blade 10 guides the steam to the moving blade 9 efficiently. The moving blade 9 rotates based on steam energy. The rotor shaft 11 outputs the rotational force obtained from the moving blade 9 to the outside.

  FIG. 2 is an external view of the steam turbine 5 as viewed from the low-pressure final stage 14 side. FIG. 3 is an enlarged view of the stationary blade 10 as viewed from the back side. As shown in FIGS. 1, 2, and 3, the stationary blade 10 has an inner end 10 </ b> A and an outer end 10 </ b> B with respect to the radial direction R with respect to the axis AX. The end 10A is fixed to the shroud 12 by welding. The end portion 10B is fixed to the blade root ring 13 by welding.

  The pair of moving blades 9 and stationary blades 10 constitute one stage 14. The steam turbine 5 has a plurality of stages 14. The plurality of stages 14 are arranged so that the dimensions of the moving blade 9 and the stationary blade 10 in the radial direction R increase from the upstream side toward the downstream side of the steam passage 8. The stage 14 at the most downstream side of the steam passage 8 is called the low-pressure final stage 14. The dimension of the stationary blade 10 of the low-pressure final stage 14 with respect to the radial direction R is larger than the dimension of the stationary blade 10 of the upstream stage 14.

  As shown in FIGS. 2 and 3, in the low-pressure final stage 14, a plurality of stationary blades 10 are arranged at a predetermined interval in the circumferential direction P of the axis AX (rotor shaft 11). The plurality of stationary blades 10 arranged in the circumferential direction P is called a blade group 15.

  Next, the stationary blade 10 according to the present embodiment will be described. FIG. 4 is a cross-sectional view illustrating an example of the stationary blade 10 according to the present embodiment. FIG. 5 is a view of the stationary blade 10 according to the present embodiment as viewed from the ventral side 23. 4 is a cross-sectional view taken along line AA in FIG.

  As shown in FIGS. 4 and 5, the stationary blade 10 is disposed in the front edge portion 21, the rear edge portion 22, the ventral side portion 23, the back side portion 24, the cavity portion 25, and the cavity portion 25. A damper member 26, and an additional member 27 connected to the damper member 26 and fixed to at least a part of the damper member 26. The cavity 25 is an internal space provided inside the stationary blade 10.

  The stationary blade 10 includes a ventral member 28 and a back member 29 that is at least partially connected to the ventral member 28. A part of the ventral member 28 and a part of the dorsal member 29 are connected by a welded portion 30. A part of the ventral member 28 and a part of the dorsal member 29 are connected by a welded portion 31. The front edge portion 21 of the stationary blade 10 includes a welded portion 30. The rear edge portion 22 of the stationary blade 10 includes a welded portion 31. In the present embodiment, the ventral member 28 and the dorsal member 29 are connected to each other at the front edge portion 21 and the rear edge portion 22 by welding. The ventral portion 23 of the stationary blade 10 includes a ventral member 28. The back side portion 24 of the stationary blade 10 includes a back side member 29.

  The cavity portion 25 is provided between the ventral member 28 and the back member 29. The ventral member 28 has a first inner surface 28A that faces the cavity (inner space) 25, and a first outer surface 28B that faces in the opposite direction of the first inner surface 28A and faces the outer space. The dorsal member 29 has a second inner surface 29A facing the cavity 25 and a second outer surface 29B facing the opposite direction of the second inner surface 29A and facing the external space. The first outer surface 28B may be referred to as an abdominal surface 28B. The second outer surface 29B may be referred to as a back surface 29B.

  Each of the ventral member 28 and the dorsal member 29 is a curved metal plate member. The ventral member 28 is curved so that the first outer surface 28B is recessed. The dorsal member 29 is curved so that the second outer surface 29B protrudes.

  As shown in FIG. 5, the ventral member 28 and the dorsal member 29 are long in the wing length direction S. In the present embodiment, the blade length direction S is a direction perpendicular to the cross section of the stationary blade 10 as shown in FIG. 4 and is a direction orthogonal to the average warp line (skeleton line) C of the stationary blade 10. In the present embodiment, the blade length direction S and the radial direction R are substantially the same.

  The stationary blade 10 has a leading edge side slit 32 </ b> A and a trailing edge side slit 32 </ b> B formed in the ventral member 28. Each of the leading edge side slit 32A and the trailing edge side slit 32B is provided in the blade length direction S. The leading edge side slit 32A and the trailing edge side slit 32B are formed so as to connect the cavity portion 25 and the external space. The water adhering to the first outer surface (abdominal surface) 28B receives the vapor pressure, moves on the first outer surface 28B, and flows into the cavity 25 from the front edge side slit 32A, as shown by an arrow W in FIG. .

  The water that has flowed into the cavity 25 flows toward the shroud 12. As shown in FIG. 3, the shroud 12 has an opening 16 communicating with the cavity 25. As indicated by the arrow E, the water in the cavity 25 is discharged from the opening 16.

  Next, the damper member 26 and the additional member 27 will be described. FIG. 6 is a cross-sectional view showing an example of the damper member 26 and the additional member 27 according to the present embodiment. FIG. 7 is a perspective view showing a part of the damper member 26 and the additional member 27 according to the present embodiment. 4, 6, and 7, the damper member 26 includes a fixing portion 33 that is fixed to the first inner surface 28 </ b> A of the ventral member 28 that faces the cavity 25, and a back member 29 that faces the cavity 25. The contact portion 34 and the contact portion 35 are movable relative to the second inner surface 29A while being in contact with the second inner surface 29A. Further, the damper member 26 includes an intermediate portion 36 disposed between the fixed portion 33 and the contact portion 34, and an intermediate portion 37 disposed between the fixed portion 33 and the contact portion 35.

  The damper member 26 is provided for suppressing vibration (self-excited vibration) of the stationary blade 10 and damping the generated vibration of the stationary blade 10. The damper member 26 is manufactured by curving a rectangular plate-shaped member by pressing. The thickness of the plate member is determined by a standard (for example, JIS standard). A bent portion 38 is provided between the fixed portion 33 and the intermediate portion 36. A bent portion 39 is provided between the intermediate portion 36 and the contact portion 34. A bent portion 40 is provided between the fixed portion 33 and the intermediate portion 37. A bent portion 41 is provided between the intermediate portion 37 and the contact portion 35.

  The damper member 26 is elastically deformable. The damper member 26 disposed in the cavity portion 25 can apply an outward force to the cavity portion 25 to each of the first inner surface 28A and the second inner surface 29A. That is, in this embodiment, the damper member 26 functions as a biasing member (elastic member, leaf spring member) that presses the abdominal member 28 and the back member 29 from the inside by elastic force.

  The fixing portion 33 is defined on the base portion (base portion) of the damper member 26. The contact portion 34 is defined at one end portion of the damper member 26. The contact portion 35 is defined at the other end portion of the damper member 26. The contact portion 34 is disposed closer to the front edge portion 21 than the fixed portion 33. The contact portion 35 is disposed closer to the rear edge portion 22 than the fixed portion 33.

  The fixing portion 33 has a facing surface 33A that can face the first inner surface 28A, and a back surface 33B that faces the opposite direction of the facing surface 33A. The facing surface 33A has substantially the same curvature as that of the first inner surface 28A. In the present embodiment, at least a part of the facing surface 33A and the first inner surface 28A are fixed. In the present embodiment, the facing surface 33A and the first inner surface 28A are fixed via the welded portion 42.

  The contact portion 34 has a facing surface 34A that can face the second inner surface 29A, and a back surface 34B that faces the opposite direction of the facing surface 34A. The facing surface 34A has substantially the same curvature as that of the second inner surface 29A. At least a part of the facing surface 34A is in contact with the second inner surface 29A. The facing surface 34A and the second inner surface 29A are not fixed. The opposing surface 34A and the second inner surface 29A are relatively movable (slidable) in a contact state.

  The contact portion 35 has a facing surface 35A that can face the second inner surface 29A, and a back surface 35B that faces the opposite direction of the facing surface 35A. The facing surface 35A has substantially the same curvature as that of the second inner surface 29A. At least a part of the facing surface 35A is in contact with the second inner surface 29A. The facing surface 35A and the second inner surface 29A are not fixed. The opposing surface 35A and the second inner surface 29A are relatively movable (slidable) in a contact state.

  The intermediate portion 36 has a front surface 36A disposed between the facing surface 33A and the back surface 34B, and a back surface 36B facing the opposite direction of the front surface 36A.

  The intermediate portion 37 has a front surface 37A disposed between the facing surface 33A and the back surface 35B, and a back surface 37B facing the opposite direction of the front surface 37A.

  The area of the facing surface 34A of the contact portion 34 that contacts the second inner surface 29A is larger than the area of the facing surface 33A of the fixed portion 33 that is fixed to the first inner surface 28A. The area of the facing surface 35A of the contact portion 35 that contacts the second inner surface 29A is larger than the area of the facing surface 33A of the fixed portion 33 that is fixed to the first inner surface 28A.

  The additional member 27 is fixed to at least a part of the damper member 26 in order to adjust the rigidity of the damper member 26. By fixing the additional member 27 to the damper member 26, the rigidity of the damper member 26 is increased. The additional member 27 is fixed to the damper member 26 by welding, for example.

  The additional member 27 is fixed to at least one of the intermediate part 36 and the intermediate part 37. In the present embodiment, the additional member 27 is fixed to at least a part of the surface of the intermediate part 36 and at least a part of the surface of the intermediate part 37. The surface of the intermediate portion 36 includes at least one of the front surface 36A and the back surface 36B. The surface of the intermediate portion 37 includes at least one of the front surface 37A and the back surface 37B.

  In the present embodiment, the additional member 27 is fixed to each of the front surface 36A, the back surface 36B, the front surface 37A, and the front surface 37B. The additional member 27 is fixed to the front surface 36A and the front surface 37A, and may not be fixed to the back surface 36B and the back surface 37B. The additional member 27 is fixed to the intermediate part 36 and may not be fixed to the intermediate part 37, or may be fixed to the intermediate part 37 and not fixed to the intermediate part 36.

  In the present embodiment, the additional member 27 is fixed to the back surface 34B of the contact portion 34 and the back surface 35B of the contact portion 35. The additional member 27 is fixed to the back surface 34B and may not be fixed to the back surface 35B, or may be fixed to the back surface 35B and not fixed to the back surface 34B.

  FIG. 8 is a view of the damper member 26 as viewed from the facing surface 34A and the facing surface 35A side. As shown in FIG. 8, the damper member 26 is long in the blade length direction S (radial direction R). The end 10 </ b> A of the stationary blade 10 includes the end 26 </ b> A of the damper member 26, and the end 10 </ b> B of the stationary blade 10 includes the end 26 </ b> B of the damper member 26.

  In the present embodiment, the additional member 27 is disposed at least in the central portion of the damper member 26 with respect to the radial direction R. In the example illustrated in FIG. 8, the additional member 27 is disposed in each of the center portion, the end portion 26A, and the end portion 26B of the damper member 26 with respect to the radial direction R. In the present embodiment, the dimension of the additional member 27 with respect to the radial direction R is substantially equal to the dimension of the damper member 26. Note that a plurality of additional members 27 may be disposed in the center portion, the end portion 26A, and the end portion 26B of the damper member 26 with respect to the radial direction R.

  FIG. 9 is a diagram illustrating an example of the additional member 27 disposed on the damper member 26. As illustrated in FIG. 9, the additional member 27 is disposed at the center portion of the damper member 26 with respect to the radial direction R, and may not be disposed at the end portion 26A and the end portion 26B.

  Next, the operation of the damper member 26 according to this embodiment will be described. A stationary blade (hollow stationary blade) 10 having a hollow portion 25 has a lower natural frequency than a solid stationary blade having no hollow portion. Therefore, depending on the operating conditions during operation of the steam turbine 5, self-excited vibration (flutter) may occur in the stationary blade 10, and the stationary blade 10 may be elastically deformed. For example, the ventral member 28 is elastically deformed toward the rear edge 22, and the back member 29 is elastically deformed toward the front edge 21, so that the first inner surface 28 </ b> A of the ventral member 28 and the back of the back member 29 are There is a possibility that a relative position change occurs between the second inner surface 29A.

  In the present embodiment, the damper member 26 is disposed in the cavity 25, and between the facing surface 34 </ b> A of the contact portion 34 and the second inner surface 29 </ b> A of the back side member 29, the facing surface 35 </ b> A of the contact portion 35 and the back side. A dynamic frictional force is generated in at least one of the second inner surface 29 </ b> A of the member 29 in a direction that suppresses a relative positional variation between the abdominal member 28 and the back member 29. By this dynamic friction force, a relative position variation between the ventral member 28 and the dorsal member 29 is suppressed. As a result, the self-excited vibration of the stationary blade 10 is suppressed.

  In the present embodiment, the fixing portion 33 is formed along the first inner surface 28A of the ventral member 28 and is fixed to the first inner surface 28A. The contact portion 34 and the contact portion 35 are formed along the second inner surface 29A of the back member 29, and are relatively movable (slidable) in a state of being in contact with the second inner surface 29A. Therefore, the contact portion 34 and the contact portion 35 and the back side member 29 slide while the abdomen side member 28 and the damper member 26 are positioned by the fixing portion 33.

  In the present embodiment, the damper member 26 is slightly elastically deformed by bending in a state (initial state) arranged in the cavity 25. Due to this elastic force, the fixing portion 33 of the damper member 26 pushes the first inner surface 28A of the ventral member 28 from the inside, and each of the contact portion 34 and the contact portion 35 pushes the second inner surface 29A of the back side member 29 from the inside. Push. That is, when the damper member 26 is disposed in the cavity 25, each of the abdominal member 28 and the dorsal member 29 is urged (pushed) toward the outside.

  When the stationary blade 10 is elastically deformed, the damper member 26 causes the dynamic friction force according to the urging force between the facing surface 34A of the contact portion 34 and the facing surface 35A of the contact portion 35 and the second inner surface 29A of the back side member 29. Give rise to By this dynamic friction force, a relative position variation between the ventral member 28 and the dorsal member 29 is suppressed.

  Next, the operation of the additional member 27 according to this embodiment will be described. The damper member 26 is designed so that the self-excited vibration of the stationary blade 10 is suppressed. The vibration reduction effect (damping effect) of the damper member 26 changes based on the rigidity of the damper member 26. For this reason, in the design stage, the rigidity of the damper member 26 from which the desired damping effect is obtained is determined, and the shape and plate thickness of the damper member 26 are determined so as to obtain the rigidity.

  For example, in consideration of cost reduction and procurement convenience, when a plate-like member having a standardized thickness is adopted as a plate-like member for manufacturing the damper member 26, a plate thickness suitable for the request is used. It may be difficult to procure the plate-shaped member. On the other hand, without adopting a plate-like member having a standardized thickness, for example, if an attempt is made to manufacture a plate-like member having a thickness that meets the requirements by cutting a thick-walled member, the cost increases and the man-hours Bring about an increase.

  Even when the damper member 26 is manufactured and the damper member 26 is manufactured by pressing a plate member having a thickness suitable for the demand and pressing the plate member, for example, manufacturing error or contact Depending on the contact state between the portion 34 and the contact portion 35 and the back-side member 29, the expected attenuation effect may not be obtained. As a result, for example, the design of the damper member 26 needs to be changed or the damper member 26 needs to be remanufactured, resulting in an increase in cost and man-hour.

  Therefore, in the present embodiment, after the damper member 26 is manufactured, the damper member 26 can obtain the desired damping effect, in other words, the stationary blade 10 can obtain the vibration characteristics that meet the requirements. The additional member 27 is added to the damper member 26. As described above, the damping effect of the damper member 26 changes based on the rigidity of the damper member 26. Therefore, after the damper member 26 is manufactured, an additional member 27 is added to the damper member 26 to adjust the rigidity of the damper member 26 so that the damper member 26 has the desired rigidity.

  For example, the vibration test (excitation test) of the stationary blade 10 is performed in a state where the damper member 26 is manufactured and the damper member 26 is disposed in the cavity portion 25. The vibration characteristics of the stationary blade 10 are acquired by the vibration test. The vibration characteristics of the stationary blade 10 include the vibration mode of the stationary blade 10 and the natural frequency. Further, the damping effect of the damper member 26 is also acquired by the vibration test. Based on the result of the vibration test, an additional member added to the damper member 26 so that the stationary blade 10 can obtain a desired vibration characteristic (so that the damper member 26 exhibits a desired damping effect). The mass of 27 and the position to add are determined. The additional member 27 having the determined mass is fixed at a predetermined position of the determined damper member 26, whereby the stationary blade 10 can obtain the desired vibration characteristics.

  Hereinafter, an example of a method for manufacturing the stationary blade 10 according to the present embodiment will be described with reference to FIG. FIG. 10 is a flowchart showing an example of a method for manufacturing the stationary blade 10 according to the present embodiment.

  The stationary blade 10 including the damper member 26 is designed (step S1). The damper member 26 is designed so that the damper member 26 can obtain a desired damping effect.

  After the damper member 26 is designed, the plate-like member is pressed based on the design to produce the damper member 26 (step S2). The plate member has a standardized thickness. The damper member 26 is manufactured by pressing the plate-like member having the standardized thickness. Moreover, the ventral member 28 and the dorsal member 29 are also manufactured based on the design.

  Next, the abdominal member 28, the back member 29, and the damper member 26 are assembled (step S3). That is, the base portion (fixed portion) 33 of the damper member 26 is fixed to the first inner surface 28 </ b> A of the ventral member 28. One end portion (contact portion) 34 and the other end portion (contact portion) 35 of the damper member 26 are in contact with the second inner surface 29 </ b> A of the back side member 29. With the base 33 of the damper member 26 fixed to the first inner surface 28A of the ventral member 28 and the one end 34 and the other end 35 of the damper member 26 fixed to the second inner surface 29A of the back member 29, the front side The ventral member 28 and the dorsal member 29 are connected to each other at the edge and the rear edge. Thereby, the damper member 26 is disposed in the cavity 25.

  After the stationary blade 10 is manufactured by assembling the abdominal member 28, the back member 29, and the damper member 26, a vibration test (vibration test) of the stationary blade 10 is performed (step S4). The vibration characteristics of the stationary blade 10 are acquired by the vibration test. Further, the damping effect of the damper member 26 is also acquired by the vibration test.

  Based on the result of the vibration test, the additional member 27 added to the damper member 26 so that the stationary blade 10 can obtain the desired vibration characteristics (so that the damper member 26 exhibits the desired damping effect). And the position to add is determined. The added member 27 having the determined mass is added (fixed) to a predetermined position of the determined damper member 26 (step S5). By adding the additional member 27 to the damper member 26, the rigidity of the damper member 26 is adjusted, and the stationary blade 10 can obtain the desired vibration characteristics.

  As described above, according to the present embodiment, since the stationary blade 10 has the hollow portion 25, the weight of the stationary blade 10 can be reduced. By providing the damper member 26 in the hollow portion 25, even if the stationary blade 10 is elastically deformed by self-excited vibration, the contact portion 34 and the contact portion 35 of the damper member 26 and the second inner surface 29A are in contact with each other. It moves, friction arises between the contact part 34 and the contact part 35, and the 2nd inner surface 29A, The elastic deformation of the stationary blade 10 is suppressed by the friction. Therefore, the self-excited vibration of the stationary blade 10 is suppressed. For example, the relative position fluctuation between the ventral member 28 and the dorsal member 29 is suppressed by the friction. Thereby, the self-excited vibration of the stationary blade 10 is suppressed. Then, by adding the additional member 27 to the damper member 26 and adjusting the rigidity of the damper member 26, the vibration reduction effect of the damper member 26 is adjusted with a simple configuration and method. Therefore, the stationary blade 10 can obtain vibration characteristics that meet the requirements. Therefore, the self-excited vibration of the stationary blade 10 is suppressed, and the deterioration of the performance of the stationary blade 10 is suppressed.

  According to the present embodiment, due to the problems in the design and manufacturing stage of the damper member 26 such as the difficulty in procuring a plate-shaped member having a thickness that meets the requirements as described above, manufacturing errors, etc. Both post-manufacturing issues such as the inability to obtain a damping effect can be solved with a simple configuration and technique.

  Further, according to the present embodiment, the damper member 26 having an arbitrary rigidity can be easily obtained even if a plate-like member having a standardized thickness is used. According to this embodiment, the stationary blade 10 including the damper member 26 is designed and manufactured so that self-excited vibration is suppressed, and the manufactured stationary blade 10 cannot obtain vibration characteristics that meet the requirements. However, by adding the additional member 27 to the damper member 26 based on the result of the vibration test, it is possible to manufacture the stationary blade 10 having the vibration characteristics suitable for the request without remanufacturing the damper member 26. Therefore, it is possible to manufacture the stationary blade 10 having the vibration characteristics meeting the requirements while suppressing the cost and labor.

  Further, in the present embodiment, the damper member 26 is elastically deformable and applies a force toward the outside of the cavity 25 to each of the first inner surface 28A and the second inner surface 29A. When the damper member 26 biases each of the ventral member 28 and the dorsal member 29 toward the outside, a relative position variation occurs between the ventral member 28 and the dorsal member 29, the damper member 26. Generates a dynamic friction force having a magnitude corresponding to the urging force between at least one of the abdominal member 28 and the back member 29. Then, by adjusting the rigidity of the damper member 26 with the additional member 27 or adjusting the urging force of the damper member 26 in the state of being disposed in the hollow portion 25 (initial state), the abdominal member 28 and the dorsal member 29, position fluctuations can be suppressed.

  In the present embodiment, the damper member 26 has an intermediate part 36 and an intermediate part 37, and the additional member 27 is fixed to at least one of the intermediate part 36 and the intermediate part 37. Thereby, the rigidity of the damper member 26 can be effectively increased.

  In addition, according to the present embodiment, the damper member 26 includes the facing surface 34A and the facing surface 35A that face the second inner surface 29A, and the back surface 34B and the back surface 35B that face the opposite directions of the facing surface 34A and the facing surface 35A, respectively. The additional member 27 is fixed to the back surface 34B and the back surface 35B. Thereby, the rigidity of the damper member 26 can be adjusted without disturbing the relative movement (sliding) of the opposing surface 34A and the opposing surface 35A of the damper member 26 and the second inner surface 29A.

  Further, according to the present embodiment, the additional member 27 is fixed to the central portion of the damper member 26 at least in the radial direction R. The stationary blade 10 has an inner end portion 10A and an outer end portion 10B fixed with respect to the radial direction R. When vibration occurs in the stationary blade 10, there is a high possibility that the amplitude of the central portion of the stationary blade 10 with respect to the radial direction R becomes large. In other words, the stationary blade 10 is highly likely to vibrate in a vibration mode in which the central portion of the stationary blade 10 becomes the antinode of vibration in the radial direction R. Therefore, the vibration of the stationary blade 10 can be effectively suppressed by fixing the additional member 27 at least at the center of the damper member 26 that becomes the antinode of vibration.

  Further, according to the present embodiment, the damper member 26 includes the contact portion 34 disposed on the front edge portion 21 side with respect to the fixed portion 33 and the contact portion 35 disposed on the rear edge portion 22 side. This stabilizes the contact between the damper member 26 and the second inner surface 29A. Further, even when vibration is significantly generated in either the front edge portion 21 or the rear edge portion 22, the vibration can be effectively damped.

  Further, according to the present embodiment, the area of the facing surface 34A of the contact portion 34 that contacts the second inner surface 29A is larger than the area of the facing surface 33A of the fixed portion 33 that is fixed to the first inner surface 28A. Similarly, the area of the facing surface 35A of the contact portion 35 that contacts the second inner surface 29A is larger than the area of the facing surface 33A of the fixed portion 33 that is fixed to the first inner surface 28A. Since the contact areas of the contact portion 34 and the contact portion 35 that are in contact with the second inner surface 29A are large, the vibration reduction effect by the damper member 26 can be enhanced.

  Further, according to the present embodiment, the leading edge side slit 32A and the trailing edge side slit 32B that connect the cavity (internal space) 25 of the stationary blade 10 and the external space are provided. Thereby, water droplets adhering to the first outer surface 28 </ b> B of the stationary blade 10 can be taken into the cavity portion 25 and removed. Therefore, the performance of the stationary blade 10 can be improved.

  In the above-described embodiment, the fixed portion 33 is fixed to the first inner surface 28A, and the contact portion 34 and the contact portion 35 are movable relative to the second inner surface 29A in a state where the contact portion 34 and the contact portion 35 are in contact with the second inner surface 29A. It was. The fixed portion 33 may be fixed to the second inner surface 29A, and the contact portion 34 and the contact portion 35 may be movable relative to the first inner surface 28A in a state of being in contact with the first inner surface 28A.

  In the present embodiment, the additional member 27 is a plate-like member. The additional member 27 may be a rod-shaped member. Further, the additional member 27 may be arranged so as to be bridged between the back surface 36B of the intermediate portion 36 and the back surface 37B of the intermediate portion 37. A plurality of additional members 27 fixed to each of the back surface 36B and the back surface 37B may be arranged in the blade length direction S between the back surface 36B and the back surface 37B.

  In the above-described embodiment, the base portion (base portion) of the damper member 26 is the fixing portion 33 that is fixed to at least one of the abdominal member 28 and the back member 29. That is, in the above-described embodiment, a part of the damper member 26 is fixed to at least one of the ventral member 28 and the dorsal member 29. The damper member 26, the ventral member 28, and the dorsal member 29 may not be fixed. For example, in the above-described embodiment, not only the contact portion (one end portion) 34 and the contact portion (other end portion) 35 but also the base portion of the damper member 26 is in contact with at least one of the first inner surface 28A and the second inner surface 29A. It may be a contact part (sliding part) that can be relatively moved in this state.

  In the above-described embodiment, the structure of the damper member 26 is arbitrary. For example, the damper member 26 may be a leaf spring member whose cross section exhibits a wave shape, as disclosed in Japanese Patent Application Laid-Open No. 2008-133825, or a leaf spring member whose cross section exhibits a substantially C-order shape, A split structure or a slit structure in which the end of the plate spring member is divided into a plurality of plates in the plate thickness direction may be used, or a plate spring member having a U-shaped cross section may be used. By adding the additional member 27 to these leaf spring members, the stationary blade 10 can obtain vibration characteristics that meet the requirements.

  Further, for example, at least one of the damper member 26 and the additional member 27 described in the above embodiment is applied to a support (wing) having a hollow interior as disclosed in Japanese Patent Publication No. 07-092002. Good. For example, the additional member 27 may be added to the internal strut reinforcing material disposed in the hollow interior, the damper member 26 may be disposed in the hollow interior, or the additional member 27 is added to the damper member 26. May be.

  Alternatively, the damper member 26 and the additional member described in the above-described embodiment may be provided on a wing having a cavity, a rib disposed in the cavity, and a damping member as disclosed in, for example, Japanese Patent Application Laid-Open No. 2010-203435. At least one of 27 may be applied. For example, the additional member 27 may be added to the rib, the damper member 26 may be disposed in the cavity, or the additional member 27 may be added to the damper member 26.

  Further, the damper member 26 and the additional member described in the above-described embodiment are added to the fan blade as disclosed in Japanese Patent Laid-Open No. 2009-068493 and the blade as disclosed in US Pat. No. 5,284,011. At least one of 27 may be applied.

DESCRIPTION OF SYMBOLS 1 Steam turbine system 5 Steam turbine 10 Stator blade 11 Rotor shaft 21 Front edge part 22 Rear edge part 23 Ventral side part 24 Back side part 25 Cavity part 26 Damper member 27 Additional member 28 Abdominal side member 28A 1st inner surface 29 Back side member 29A Second inner surface 33 Fixed portion 33A Opposing surface 34 Contact portion 34A Opposing surface 34B Back surface 35 Contacting portion 35A Opposing surface 35B Back surface 36 Intermediate portion 37 Intermediate portion

Claims (9)

A stationary blade used in a steam turbine,
A ventral member;
A back side member connected to the ventral member at each of the front edge and the rear edge, and a cavity is provided between the ventral member,
A fixed portion that is disposed in the cavity and is fixed to one of the first inner surface of the ventral member and the second inner surface of the back member that faces the cavity, and is in contact with the other inner surface A damper member having a contact portion relatively movable in a state;
A stationary blade comprising: an additional member that is fixed to at least a part of the damper member and adjusts the rigidity of the damper member.   The stator blade according to claim 1, wherein the damper member is elastically deformable and applies an outward force to the first inner surface and the second inner surface with respect to the cavity. The damper member has an intermediate part between the fixed part and the contact part,
The stationary blade according to claim 1 or 2, wherein the additional member is fixed to at least a part of a surface of the intermediate portion. The damper member has a facing surface facing the other inner surface, and a back surface facing the opposite direction of the facing surface,
The stationary blade according to any one of claims 1 to 3, wherein the additional member is fixed to the back surface.   The stationary blade according to any one of claims 1 to 4, wherein the additional member is fixed to a central portion of the damper member at least in a radial direction with respect to a rotation axis of a rotor shaft of the steam turbine.   The said contact part is a stationary blade as described in any one of Claims 1-5 arrange | positioned at the said front edge part side and the said rear edge part side rather than the said fixing | fixed part, respectively.   The stationary blade according to any one of claims 1 to 6, wherein an area of the contact portion that contacts the other inner surface is larger than an area of the fixed portion that is fixed to the one inner surface. A rotor shaft;
A steam turbine comprising: the stator blade according to any one of claims 1 to 7 disposed in a circumferential direction of the rotor shaft. A method of manufacturing a stationary blade used in a steam turbine,
The stationary blade includes a ventral member, a back member capable of forming a cavity portion between the ventral member, and a damper member for attenuating vibration of the stationary blade,
Designing the damper member so as to obtain the desired damping effect;
Based on the design, a step of manufacturing the damper member by pressing a plate-shaped member;
In a state where the base portion of the damper member is fixed to one inner surface of the first inner surface of the ventral member and the second inner surface of the back member, and the end portion of the damper member is in contact with the other inner surface, Connecting the ventral member and the dorsal member at each of the front edge and the rear edge, and disposing the damper member in the cavity;
Performing a vibration test of the stationary blade to obtain vibration characteristics of the stationary blade;
A step of adding an additional member to at least a part of the damper member based on the result of the vibration test to adjust the rigidity of the damper member.

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