JP2014114734A - Turbine blade and turbine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a turbine blade for suppressing a change in the natural frequency of the turbine blade while damping the vibration of the turbine blade during the operation of a turbine, and to provide the turbine.SOLUTION: A damping part 33 is installed in a recessed part formed ranging from an inside shroud opposite surface 34a toward the inside of an inside shroud 22a, and a connection part 32 as a protruded part for connecting inside shrouds 22a, 22b is extended from an inside shroud opposite surface 34b and the extension portion of the connection part 32 is stored in the damping part 33 of the inside shroud 22a. The connection part 32 and the damping part 33 constitute a damper mechanism 31 as a vibration damping mechanism for damping vibration generated in a turbine stator blade 17.

Description

  The present invention relates to a turbine blade and a turbine that attenuate vibration caused by pressure of a working fluid.

  A general turbine (for example, a gas turbine) includes a compressor, a combustor, and a turbine section. In the turbine section, a rotor, which is a rotating shaft, is rotatably supported in a vehicle interior, a moving blade is installed on the outer periphery of the rotor, a stationary blade is installed on the inner wall of the vehicle compartment, and a stationary blade is installed in a gas passage. A plurality of moving blades are alternately arranged. The compressor compresses the air taken in from the air intake port into high-temperature and high-pressure compressed air, and the combustor mixes and burns fuel with this compressed air, and the high-temperature and high-pressure combustion that is the working fluid Generate gas. In the turbine section, the moving blades and the rotor are rotationally driven by the combustion gas, and the generator connected to the rotor is driven.

  By the way, in a turbine section provided with a plurality of stationary blades and moving blades, both end portions of each stationary blade are respectively supported by an inner shroud and an outer shroud arranged in an annular shape fixed to the casing. Micro vibrations are generated on the blades during operation of the gas turbine. For example, during operation of a gas turbine, the working fluid flowing out from between the moving blades located upstream in the flow direction of the working fluid acts as an external force on the stationary blade located downstream of the moving blade, Vibrate. In particular, when the frequency of the external force matches the natural frequency of the stationary blade, the stationary blade is in a resonance state. Here, when the inner shrouds of a plurality of stationary blades are independently connected, a relative displacement is generated in the connecting portion due to the vibration described above, and the vibration is slightly attenuated by the frictional resistance due to the relative displacement. However, there is a problem that the wear of the connecting portion proceeds.

  Further, turbine blades of recent turbines have been made thinner and have higher aspect ratios in order to achieve higher efficiency and lower costs. For this reason, in order to improve the reliability of the strength against the vibration of the turbine blade, a vibration damping mechanism that attenuates the vibration of the turbine blade is employed.

  As a gas turbine equipped with such a vibration damping mechanism for a stationary blade, for example, in Patent Document 1, in a compressor, a stationary blade disposed in a fluid passage and an inner periphery end supporting the stationary blade on a disk are disclosed. A gas turbine is described that includes a circumferential shroud and seal member and a mesh wire disposed in a compressed state. The mesh wire is a metal fiber member that is disposed in a compressed state in a buffer housing chamber formed between the inner peripheral shroud and the seal member, and the mesh wire contact point that contacts the inner peripheral shroud and the seal member is Slide against them. By this sliding, the vibration energy of the stationary blade is converted into frictional energy due to sliding friction of sliding, and the vibration is attenuated.

  Moreover, as a gas turbine provided with a vibration damping mechanism for a stationary blade, for example, Patent Document 2 discloses an end housing that forms a space between a shroud portion disposed at an end portion of the stationary blade body and the shroud portion. A gas turbine is described that includes a body and an elastic member that is disposed in space and biases the shroud portion and the end housing in a direction to separate them. When the spring, which is an elastic member, slides on the shroud portion, the vibration energy of the stationary blade (including the stationary blade body and the shroud portion) is converted to the friction energy by sliding sliding friction, and the vibration is attenuated. The

JP 2009-68338 A JP 2010-151044 A

  However, in the gas turbine described in Patent Document 1, there is a problem that the natural frequency of the stationary blade changes due to the sliding of the mesh wire contact portion that contacts the inner shroud and the seal member. In addition, when the natural frequency of the stationary blade changes, it is difficult to accurately predict the natural frequency of the stationary blade and deviate from the excitation frequency that is expected to act on the stationary blade, that is, to detune the design. is there. The gas turbine described in Patent Document 2 also has the same problem.

  The present invention has been made in order to solve the above-described problems, and a turbine blade and a turbine that suppress changes in the natural frequency of the turbine blade while attenuating the vibration of the turbine blade during operation of the turbine. The purpose is to provide.

  In order to solve the above problems, a turbine blade according to the present invention includes a plurality of blade bodies disposed in a space in which a working fluid flows, a shroud that supports an end portion of the blade body, and a space between the adjacent shrouds. And a damper mechanism that is connected and formed in an annular shape, the damper mechanism having viscoelasticity with respect to relative motion between the adjacent shrouds. Of these, the blade body is a stationary blade body having a tip portion supported by the shroud, and the damper mechanism is formed by connecting between the shrouds supporting the adjacent stationary blade bodies in an inner circumferential direction. It is good also as what is formed. Further, the blade body is a moving blade body whose tip is supported by the shroud, and the damper mechanism is formed in an annular shape by connecting the shrouds supporting the adjacent moving blade bodies in the outer circumferential direction. It is good also as what to do.

  Thus, by adopting a structure in which two adjacent shrouds are connected by a damper mechanism, the vibration generated in the turbine blade can be attenuated by the viscoelastic property of the damper mechanism, and the durability of the turbine blade is improved. be able to. Further, by providing a damper mechanism between two adjacent shrouds, the rigidity with respect to the change in the distance between the shrouds is small, so that the change in the natural frequency of the turbine blade can be suppressed. Therefore, the natural frequency of the turbine blade can be easily predicted, and a detuning design can be made to deviate from the excitation frequency expected to act on the turbine blade.

  Moreover, the turbine blade according to the present invention is characterized in that the damper mechanism is a mechanism for connecting the adjacent shrouds with a spring portion having elasticity and a dashpot portion having viscosity.

  Thereby, the damper mechanism has viscoelasticity with respect to the relative movement between adjacent shrouds, and attenuates the vibration of the turbine blades generated during operation of the gas turbine, that is, the minute movement generated between the adjacent shrouds. be able to.

  Further, in the turbine blade according to the present invention, the damper mechanism is installed in a recess formed from one of the opposing surfaces toward the inside of the shroud having the opposing surface among the opposing surfaces between the adjacent shrouds. A damping portion that is a rubber member, and a connecting portion that extends from the other facing surface toward the one facing surface, and the extending portion of the connecting portion is embedded in the damping portion It is characterized by that.

  Thus, since the damping part is a rubber member, it can be easily installed on the shroud, and a damper mechanism can be configured easily.

  Further, in the turbine blade according to the present invention, the damper mechanism is installed in a recess formed from one of the opposing surfaces toward the inside of the shroud having the opposing surface among the opposing surfaces between the adjacent shrouds. The metal fiber braided structure, and a connecting portion extending from the other facing surface toward the one facing surface, and the extending portion of the connecting portion includes It is characterized by being embedded in the attenuation part. The metal fiber is preferably formed of Inconel (registered trademark).

  Thus, by forming the metal fiber from Inconel (registered trademark), high temperature resistance can be ensured for the working fluid having high temperature and pressure.

  Further, a turbine according to the present invention includes a turbine casing, a plurality of any one of the above-described turbine blades disposed in the turbine casing, and a rotor disposed at the center of the turbine blade, The rotor rotates as the working fluid flows through the turbine blades.

  As a result, by using a structure in which two adjacent shrouds are connected by a damper mechanism, the vibration generated in the turbine blades can be attenuated due to the viscoelastic nature of the damper mechanism, thereby improving the durability of the turbine blades. Turbine can be obtained.

  According to the turbine blade according to the present invention, it is possible to suppress a change in the natural frequency of the turbine blade while attenuating the vibration of the turbine blade during operation of the turbine.

FIG. 1 is a schematic configuration diagram of a gas turbine according to the first embodiment. FIG. 2 is a schematic diagram illustrating the stationary blade of the first embodiment. FIG. 3 is a schematic diagram illustrating an example of a damper mechanism of the stationary blade according to the first embodiment. FIG. 4 is an equivalent structural diagram of the damper mechanism of the first embodiment. FIG. 5 is a schematic diagram illustrating an example of a damper mechanism of a stationary blade according to the second embodiment. FIG. 6 is a schematic diagram illustrating an example of a damper mechanism of a stationary blade according to the third embodiment.

[Embodiment 1]
(Schematic configuration and operation of the gas turbine 1)
FIG. 1 is a schematic configuration diagram of a gas turbine according to the first embodiment. An outline of the structure of the gas turbine 1 of the first embodiment will be described with reference to FIG.

  As shown in FIG. 1, the gas turbine 1 according to the first embodiment includes a compressor 11, a combustor 12, a turbine unit 13, and an exhaust chamber 14. A rotor 19 is disposed through the center of the compressor 11, the combustor 12, and the turbine unit 13. A generator (not shown) is connected to the end of the rotor 19 on the exhaust chamber 14 side.

  The compressor 11 is a mechanism that takes in external air from the air intake port 15 and compresses it to generate high-temperature and high-pressure compressed air.

  The combustor 12 is a device that supplies fuel to the compressed air generated by the compressor 11 and ignites and burns to generate combustion gas.

  The turbine unit 13 is a mechanism for generating rotational power in the rotor 19 by the combustion gas generated in the combustor 12. The turbine section 13 includes a turbine casing 16 and a plurality of turbine stationary blades 17 and turbine rotor blades 18 provided in the turbine casing 16. The turbine vane 17 is fixed to the inner wall surface of the turbine casing 16 along the circumferential direction. The turbine rotor blade 18 is fixed along the circumferential direction on the outer periphery of a disk-shaped disk formed on the rotor 19. The plurality of turbine stationary blades 17 and the turbine rotor blades 18 are alternately arranged in a plurality of stages along the axial direction of the rotor 19.

  The exhaust chamber 14 is provided with a turbine stationary blade 17 and a turbine rotor blade 18 in the turbine section 13, communicates with a working fluid passage through which a combustion gas as a working fluid passes, and passes the combustion gas that has passed through the working fluid passage to the outside. To discharge.

  The air taken in from the air intake port 15 of the compressor 11 is compressed by the compressor 11 to generate high-temperature and high-pressure compressed air. The combustor 12 supplies fuel to the compressed air, and ignites and burns to generate high-temperature and high-pressure combustion gas. The combustion gas which is the working fluid passes through the working fluid passage in which the turbine stationary blade 17 and the turbine rotor blade 18 are disposed in the turbine unit 13, whereby the turbine rotor blade 18 and the rotor 19 are rotationally driven, and the rotor 19 The generator connected to is driven. The combustion gas that has passed through the working fluid passage is discharged from the exhaust chamber 14 to the outside.

(Structure of turbine stationary blade 17)
FIG. 2 is a schematic diagram illustrating the stationary blade of the first embodiment. The structure of the turbine stationary blade 17 will be described with reference to FIG.

  As shown in FIG. 2, the turbine vane 17 is supported by the inner shroud 22 at the distal end that is the radially inner portion of the rotor 19 of the stationary blade body 21, and is the proximal end that is the radially outer portion of the rotor 19. The portion is supported by the outer shroud 23. The plurality of inner shrouds 22 are connected to each other to form an annular inner shroud ring 24. The plurality of outer shrouds 23 are connected to each other to form an annular outer shroud ring 25, and the outer shroud ring 25 is fixed to the inner wall surface of the turbine unit 13.

  The turbine stationary blade 17 configured in this way vibrates in response to an external force due to the working fluid flowing out from the turbine blade 18 located upstream in the flow direction of the working fluid in the turbine section 13 during operation of the gas turbine 1. To do. Therefore, the turbine stationary blade 17 of the gas turbine 1 according to the first embodiment is provided with a vibration damping mechanism that attenuates the vibration.

(Vibration damping action by damper mechanism 31)
FIG. 3 is a schematic diagram illustrating an example of the damper mechanism of the stationary blade according to the first embodiment, and FIG. 4 is an equivalent structure diagram of the damper mechanism according to the first embodiment. The damper mechanism 31 of the turbine stationary blade 17 will be described with reference to FIGS. 3 and 4.

  As shown in FIG. 3, of the pair of inner shrouds 22 adjacent to each other in the circumferential direction of the inner shroud ring 24 of the turbine vane 17, the inner shroud 22 on the left side in the drawing is an inner shroud 22 a, and the inner shroud 22 on the right side in the drawing is viewed. Is the inner shroud 22b. The stationary blade body 21 supported by the inner shroud 22a is referred to as a stationary blade body 21a, and the stationary blade body 21 supported by the inner shroud 22b is referred to as a stationary blade body 21b. Further, in the inner shrouds 22a and 22b, surfaces facing each other are referred to as inner shroud facing surfaces 34a and 34b, respectively. An attenuating portion 33 is installed in a recess formed from the inner shroud facing surface 34a toward the inside of the inner shroud 22a. In addition, a connecting portion 32 that is a protrusion for connecting the inner shrouds 22a and 22b extends from the inner shroud facing surface 34b toward the inner shroud facing surface 34a. The inner shroud 22a is housed in the attenuation portion 33. At least the coupling portion 32 and the damping portion 33 constitute a damper mechanism 31 that is a vibration damping mechanism that attenuates vibrations generated in the turbine vane 17 and the inner shrouds 22a and 22b are coupled to each other. Thus, the damper mechanism 31 is installed between the adjacent inner shrouds 22 in all the inner shrouds 22 constituting the inner shroud ring 24.

  FIG. 4 is an equivalent structural diagram of the damper mechanism 31 for explaining the function of the damper mechanism 31 shown in FIG. The damper mechanism 31 is equivalently represented by a structure in which the inner shrouds 22a and 22b are connected in parallel by a spring portion 41 that exhibits elasticity and a dashpot portion 42 that exhibits viscosity. As a specific configuration of the dashpot portion 42, a configuration in which a known structure in which a piston valve having a through hole is moved inside a cylinder filled with oil is considered inside the damping portion 33. In the damper mechanism 31 configured as described above, when an external force is applied in a direction in which the inner shrouds 22a and 22b are separated from each other, the distance between the inner shrouds 22a and 22b increases with the passage of time. The state returns to the original state (the state in which the spring portion 41 is not stretched). That is, the damper mechanism 31 exhibits viscoelastic properties with respect to the relative movement of the inner shrouds 22a and 22b. As described above, the damper mechanism 31 having the viscoelastic property can attenuate the vibration of the turbine stationary blade 17 generated during the operation of the gas turbine 1, that is, the minute movement generated between the inner shrouds 22a and 22b. . The damper mechanism 31 is equivalently structured such that the inner shrouds 22a and 22b are connected in parallel by the spring portion 41 and the dashpot portion 42, but is not limited thereto. That is, the damper mechanism 31 may equivalently have a structure in which the inner shrouds 22 a and 22 b are connected by a series structure of the spring portion 41 and the dashpot portion 42.

  As described above, by adopting a structure in which two adjacent inner shrouds 22 are connected by the damper mechanism 31, the vibration generated in the turbine stationary blade 17 can be attenuated due to the viscoelastic property of the damper mechanism 31. The durability of the turbine vane 17 can be improved. Further, by providing the damper mechanism 31 between the two adjacent inner shrouds 22, the rigidity with respect to the change in the distance between the inner shrouds 22 is small, so that the change in the natural frequency of the turbine stationary blade 17 can be suppressed. . Therefore, the natural frequency of the turbine vane 17 can be easily predicted, and detuned design can be performed by shifting from the excitation frequency expected to act on the turbine vane 17.

  As shown in FIG. 3, the attenuation portion 33 is installed in a recess formed in the inner shroud 22a, and the connecting portion 32 extends from the inner shroud facing surface 34b of the inner shroud 22b. It is not limited to this. That is, as a structure in which the damper mechanism 31 constituted by the connecting portion 32 and the damping portion 33 is unitized, a recess is formed in each of the inner shrouds 22a and 22b, and the unitized damper mechanism 31 is fitted and fixed in the recess. Also good. Thereby, the work efficiency at the time of forming the inner shroud ring 24 by connecting the plurality of inner shrouds 22 to each other can be improved.

  In addition, as shown in FIG. 3, the damper mechanism 31 is provided between the two inner shrouds 22 adjacent to the turbine stationary blade 17, but the present invention is not limited to this. In other words, similar to the inner shroud 22 of the turbine vane 17, adjacent outer shrouds in the outer peripheral shroud ring in which the outer peripheral shrouds supporting the tip of the rotor blade body of the turbine rotor blade 18 are connected to each other to form an annular shape. The damper mechanism 31 may be applied between the two. As a result, the same effect as described above can be obtained for the vibration generated in the turbine rotor blade 18 as well as the vibration generated in the turbine stationary blade 17.

  Moreover, although the turbine stationary blade 17 provided with the damper mechanism 31 which is a vibration damping mechanism was demonstrated as what is provided in a gas turbine, it is not limited to this, The turbine blade provided in a steam turbine or other rotary machines Also, the damper mechanism 31 can be applied.

[Embodiment 2]
The turbine blade vibration damping structure of the second embodiment will be described focusing on differences from the turbine blade vibration damping structure of the first embodiment. The schematic configuration and operation of the gas turbine of the second embodiment are the same as the schematic configuration and operation of the gas turbine of the first embodiment.

(Vibration damping action by the damper mechanism 31a)
FIG. 5 is a schematic diagram illustrating an example of a damper mechanism of a stationary blade according to the second embodiment. The damper mechanism 31a of the turbine stationary blade 17 will be described with reference to FIG.

  As shown in FIG. 5, an attenuation portion 33a is installed in a recess formed from the inner shroud facing surface 34a toward the inside of the inner shroud 22a. The damping portion 33a is a rubber member having viscoelasticity and vibration damping properties. Further, a connecting portion 32a, which is a protrusion for connecting the inner shrouds 22a, 22b, extends from the inner shroud facing surface 34b toward the inner shroud facing surface 34a, and the extending portion of the connecting portion 32a is It is embedded in the attenuation part 33a of the inner shroud 22a. The connecting portion 32a and the damping portion 33a constitute a damper mechanism 31a that is a vibration damping mechanism that attenuates the vibration generated in the turbine vane 17, and the inner shrouds 22a and 22b are connected to each other. Thus, the damper mechanism 31 a is installed between the adjacent inner shrouds 22 in all the inner shrouds 22 constituting the inner shroud ring 24.

  The damper mechanism 31a is equivalent to the inner shrouds 22a and 22b in the same manner as the damper mechanism 31 of the first embodiment by sliding the inside of the damping part 33a, which is a rubber member, with the extending part of the connecting part 32a. It is represented by a structure that is connected in parallel by a spring portion 41 that shows elasticity and a dashpot portion 42 that shows viscosity. Therefore, the damper mechanism 31a has viscoelasticity and can attenuate the vibration of the turbine vane 17 generated during operation of the gas turbine 1, that is, the minute vibration generated between the inner shrouds 22a and 22b.

  As described above, the same effect as that of the first embodiment can be obtained by connecting the two adjacent inner shrouds 22 with the damper mechanism 31a including the damping portion 33a that is a rubber member.

  Further, since the damping part 33a is a rubber member, it can be easily installed on the inner shroud 22, and the damper mechanism 31a can be configured easily.

[Embodiment 3]
The turbine blade vibration damping structure of the third embodiment will be described focusing on the differences from the turbine blade vibration damping structure of the first embodiment. The schematic configuration and operation of the gas turbine of the third embodiment are the same as the schematic configuration and operation of the gas turbine of the first embodiment.

(Vibration damping action by the damper mechanism 31b)
FIG. 6 is a schematic diagram illustrating an example of a damper mechanism of a stationary blade according to the third embodiment. The damper mechanism 31b of the turbine stationary blade 17 will be described with reference to FIG.

  As shown in FIG. 6, an attenuation portion 33b is installed in a recess formed from the inner shroud facing surface 34a toward the inside of the inner shroud 22a. The attenuation portion 33b is a structure in which metal fibers (for example, Inconel (registered trademark) wire) having viscoelasticity and vibration damping properties are knitted into a mesh shape. Further, a connecting portion 32b, which is a protrusion for connecting the inner shrouds 22a, 22b, extends from the inner shroud facing surface 34b toward the inner shroud facing surface 34a, and the extending portion of the connecting portion 32b is It is embedded in the attenuation part 33b of the inner shroud 22a. The connecting portion 32b and the damping portion 33b constitute a damper mechanism 31b that is a vibration damping mechanism that attenuates the vibration generated in the turbine stationary blade 17, and the inner shrouds 22a and 22b are connected to each other. In this way, the damper mechanism 31b is installed between the adjacent inner shrouds 22 in all the inner shrouds 22 constituting the inner shroud ring 24.

  The damper mechanism 31b is a spring in which the inner shrouds 22a and 22b are elastically equivalent to the damper mechanism 31 of the first embodiment by sliding the extension portion of the connecting portion 32b in the damping portion 33b. It represents with the structure connected in parallel by the part 41 and the dashpot part 42 which shows viscosity. Therefore, the damper mechanism 31b has viscoelasticity, and can attenuate the vibration of the turbine stationary blade 17 generated during the operation of the gas turbine 1, that is, the minute vibration generated between the inner shrouds 22a and 22b.

  As described above, the same effect as that of the first embodiment can be obtained by connecting the two adjacent inner shrouds 22 by the damper mechanism 31b including the damping portion 33b that is a braided structure of metal fibers. it can.

  Further, when the metal fiber is formed of Inconel (registered trademark) wire, high temperature resistance can be ensured against the combustion gas that is high temperature and high pressure.

  As mentioned above, although Embodiment 1-3 was demonstrated, Embodiment 1-3 is not limited by the content mentioned above. In addition, the constituent elements of Embodiments 1 to 3 described above include those that can be easily conceived by those skilled in the art, those that are substantially the same, and those that are equivalent. Furthermore, various omissions, substitutions, and changes of the components can be made without departing from the spirit of the first to third embodiments.

DESCRIPTION OF SYMBOLS 1 Gas turbine 11 Compressor 12 Combustor 13 Turbine part 14 Exhaust chamber 15 Air intake port 16 Turbine casing 17 Turbine stationary blade 18 Turbine rotor blade 19 Rotor 21, 21a, 21b Stator blade body 22, 22a, 22b Inner shroud 23 Outer shroud 24 Inner shroud ring 25 Outer shroud ring 31, 31a, 31b Damper mechanism 32, 32a, 32b Connecting portion 33, 33a, 33b Attenuating portion 34a, 34b Inner shroud facing surface 41 Spring portion 42 Dashpot portion

Claims (8)

A plurality of wing bodies arranged in a space in which the working fluid flows;
A shroud supporting the end of the wing body;
A damper mechanism formed between the adjacent shrouds to form an annular shape;
With
The turbine blade according to claim 1, wherein the damper mechanism has viscoelasticity with respect to relative movement between the adjacent shrouds. The wing body is a stationary wing body whose tip is supported by the shroud,
2. The turbine blade according to claim 1, wherein the damper mechanism is formed in an annular shape by connecting the shrouds supporting the adjacent stationary blade bodies in an inner circumferential direction. The wing body is a moving wing body whose tip is supported by the shroud,
2. The turbine blade according to claim 1, wherein the damper mechanism is formed in an annular shape by connecting the shrouds supporting the adjacent rotor blade bodies in an outer circumferential direction.   The turbine according to any one of claims 1 to 3, wherein the damper mechanism is a mechanism that connects the adjacent shrouds with a spring portion having elasticity and a dashpot portion having viscosity. Wings. The damper mechanism includes a damping portion that is a rubber member installed in a recess formed from one of the facing surfaces to the inside of the shroud having the facing surface among the facing surfaces between the adjacent shrouds; A connecting portion extending from the other facing surface toward the one facing surface,
The turbine blade according to any one of claims 1 to 3, wherein an extending portion of the connecting portion is embedded in the damping portion. The damper mechanism is a braided structure of metal fibers installed in a recess formed from one facing surface to the inside of the shroud having the facing surface among the facing surfaces between adjacent shrouds. An attenuating portion and a connecting portion extending from the other facing surface toward the one facing surface;
The turbine blade according to any one of claims 1 to 3, wherein an extending portion of the connecting portion is embedded in the damping portion.   The turbine blade according to claim 6, wherein the metal fiber is made of Inconel (registered trademark). A turbine casing,
The turbine blade according to any one of claims 1 to 7, wherein a plurality of turbine blades are disposed in the turbine casing.
A rotor disposed in the center of the turbine blade;
With
The turbine is characterized in that the rotor rotates as the working fluid flows through the turbine blades.

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