JP5956365B2 - Turbine blade cascade assembly and steam turbine equipment - Google Patents

Description

  The present invention relates to a structure of a turbine rotor cascade of a turbomachine.

  An axial-flow turbomachine such as a steam turbine or a gas turbine has a structure composed of a stationary blade and a moving blade disposed on the downstream side of the stationary blade.

  The working fluid flowing in from the upstream side of the stationary blade passes through the space between the stationary blades and flows to the upstream side of the moving blade at a predetermined outlet angle. At that time, in a region downstream from the trailing edge of the stationary blade, a region where the speed is low, so-called stationary blade wake, is formed due to the influence of the boundary layer developed on the blade surface of the stationary blade. Since the number of stator blade wakes matches the number of stator blades that form the wake, the rotor blades pass through the stator blade wakes by the number of stator blades upstream of the rotor blades as they move around the turbine axis. Will do. In addition, since the pressure field around the stationary blade interferes with the pressure field around the stationary blade as much as the number of stationary blades while the rotor blade makes a round around the turbine axis, the rotor blade is the product of the rotational frequency and the number of stationary blades. It is excited by the fluid excitation force of the stationary blade passing frequency represented by If the stationary blade passage frequency and the natural frequency of the vibration mode of the moving blade match, an excessive fluctuating stress may be generated in the moving blade due to resonance, and the moving blade may fatigue.

  Conventionally, in order to prevent fatigue failure of the moving blade, there is a case where a design is made to detune the stationary blade passing frequency at the rated rotational speed and the natural frequency of the vibration mode of the moving blade to avoid resonance. In the detuning design, there is a problem that the number of stationary blades that can be selected at the time of design is limited because the stationary blade passing frequency is changed by adjusting the number of stationary blades so as not to coincide with the natural frequency of the moving blade. In addition, even if the stationary blade passage frequency and the natural frequency of the moving blade match, the moving blade has sufficient vibration resistance so that the moving blade will not be damaged by fatigue. And there is a problem that hinders performance improvement.

  As described above, in the stage design of an axial-flow turbomachine, in order to prevent an increase in material cost and hindrance to performance improvement, it is necessary to reduce the vibration stress of each vibration mode when the moving blade resonates. It is effective to increase the damping force.

  As a conventional technique in this technical field, there is JP-A-2005-256786 (Patent Document 1). In this publication, a rotating body, a shroud array arranged around the rotating body, a moving blade array arranged between the shroud array and the rotating body and supported by the shroud array and the rotating body, The shroud row includes a first shroud and a second shroud coupled and joined to the first shroud by twisting deformation in the process of increasing the rotational speed, and the first shroud is connected to the second shroud. And the second shroud has a second coupling surface coupled to and joined to the first shroud, the first coupling surface and the second coupling surface. A centripetal body interposed between the first coupling surface and the second coupling surface, the centripetal body interposed between the first coupling surface and the second coupling surface; It is described.

JP 2005-256786 A

  A general steam turbine employs a structure in which tip covers of moving blades adjacent in the circumferential direction are brought into contact with each other as a structure for attenuating the resonance amplitude when the moving blades resonate. This is because, when the moving blades resonate and vibrate, the tip covers are brought into contact with each other, whereby a frictional damping force acts on the contact portion and the resonance amplitude can be reduced. However, there are various shapes for the blade tip cover shape and contact portion depending on the target vibration mode and blade structure, and it is generally difficult to determine which shape is effective for friction damping. . In addition, the shape of the conventional blade tip cover is such that friction damping acts on the displacement direction of the vibration mode most desired to be avoided among the vibration modes of a plurality of blades. As described above, in a turbine blade in which a plurality of vibration modes is a problem, a blade structure that can exhibit a damping effect even in a plurality of vibration modes is desirable.

  In the said patent document 1, the structure by which the alignment alignment body is installed between the blade tip covers of a moving blade is described as an Example. The alignment promoting body is formed of hard rubber having an appropriate hardness and various engineer plastics having an appropriate hardness, and its flexibility is appropriately designed. The first blade tip cover portion and the second blade tip cover portion sandwiching the alignment promoting body are coupled at the time of high-speed rotation and integrated integrally, thereby reducing the number of resonance points. It is described that, when the joint surface is deformed in the normal direction (resonance mode), the alignment promoting body uniformly disperses the surface pressure to exhibit a damping effect and reduce the resonance amplitude at the time of resonance.

  In other words, in the structure of Patent Document 1, since the alignment promoting body is coupled at the time of high-speed rotation and coupled integrally, it exhibits a damping effect only with respect to deformation in the normal direction of the joint surface. Similar to the shape of the tip cover, it has a structure that exhibits a damping effect only in one displacement direction.

  Therefore, the present invention provides a turbine blade cascade structure that exhibits a damping effect for a plurality of vibration modes and can reduce the resonance stress even when the stationary blade passing frequency and the blade natural frequency match.

  In order to solve the above problems, the present invention is to fix a plurality of turbine blades having a blade portion and a blade tip cover provided at the tip of the blade portion to a rotor of a turbomachine in the circumferential direction of the rotor. In the turbine blade cascade assembly, the rotor blade tip cover is formed on a part of the rotor circumferential side wall surface, and is formed between the contact surface that contacts the adjacent blade tip cover and the adjacent blade tip cover. Among the gaps, the gap formed between the first damping member made of a viscoelastic body and the adjacent blade tip cover provided in the gap on the rotor axial direction blade inlet side with respect to the contact surface And a second damping member made of a viscoelastic body provided in a gap portion on the rotor axial direction blade outlet side with respect to the contact surface.

  According to the present invention, the turbine rotor cascade has a simple structure and not only enhances the damping effect on the resonance amplitude of the circumferential vibration mode targeted by the conventional blade tip cover structure, but also increases the resonance amplitude of the torsional vibration mode. Since it also has a damping effect, the damping effect is exhibited for a plurality of vibration modes, and the resonance stress can be reduced even when the stationary blade passing frequency and the moving blade natural frequency coincide.

  Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

It is an example of the paragraph structure of a steam turbine. It is a figure which shows the example of the cross section which looked at the turbine blade front-end | tip cover part of the conventional structure from the radial direction. It is a figure which shows the turbine rotor blade structure which concerns on 1st Example of this invention. It is a figure explaining the 1st effect | action of this invention. It is a figure explaining the 2nd effect | action of this invention. It is a figure which shows the turbine rotor blade structure which concerns on the 2nd Example of this invention. It is a figure which shows the turbine rotor blade structure which concerns on the 3rd Example of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, although the Example described below is an example which applied this invention to the steam turbine as an example of an axial flow turbomachine, this invention is applicable not only to a steam turbine but to a gas turbine and a compressor. is there.

  A first embodiment of the present invention will be described. First, an example of a steam turbine to which the present invention is applied will be described.

  FIG. 1 is an example of a paragraph structure of a steam turbine having turbine blades. In FIG. 1, 1 is a diaphragm outer ring, 2 is a diaphragm inner ring, 3 is a stationary blade, 4 is a moving blade, 5 is a rotor, 6 is a rotor blade tip cover, 7 is a central axis of the rotor 5, and an arrow indicated by 20 is operated. The flow direction of the main stream of the vapor | steam which is a fluid is each shown. In addition, as a definition of a direction, it is a rotor axial direction from the left to the right of the drawing, a rotor radial direction from the bottom to the top, and a rotor circumferential direction from the front to the back.

  A general steam turbine includes a stationary blade row that forms an annular flow path by fixing a plurality of stationary blades 3 in the circumferential direction between a diaphragm outer ring 1 and a diaphragm inner ring 2 that are assembled in an annular shape. A paragraph in which a plurality of blades 4 formed by fixing a plurality of blades 4 in the circumferential direction to the disk portion of the rotor 5 that is a rotating body is combined on the downstream side in the flow direction of the main flow 20 of the blade row, It has a structure in which a plurality are arranged in the axial direction. A blade tip cover 6 is generally provided at the outer circumferential end of the blade portion of the blade 4, and adjacent blades are connected by the blade tip cover 6.

  The stationary blade 3 rectifies the main flow that flows in from the upstream side in the flow direction of the stationary blade 3, and plays a role of converting pressure into velocity. The energy of the main flow that has passed through the stationary blade 3 is converted into rotational energy by the moving blade 4. It is converted and the rotor 5 is rotated. The rotor 5 is connected to a generator (not shown), and generates electricity by rotating the generator.

  FIG. 2 is an example of a sectional view of a moving blade tip cover structure applied to a turbine moving blade of a general steam turbine as viewed from the radial direction. The blade tip cover is provided in each blade 4, and the blade tip cover has a different structure for each blade.

  FIG. 2 shows only two blade tip covers, ie, a first blade tip cover 8 and a second blade tip cover 9 that are adjacent to each other in the circumferential direction. As many as four blade tip covers are also arranged.

  Here, the first blade tip cover 8 and the second blade tip cover 9 shown in FIG. 2 have the same shape, and are numbered for convenience. Actually, both the first blade tip cover 8 and the second blade tip cover 9 are structures having the same role as the blade tip cover 6 shown in FIG.

  In FIG. 2, the first blade tip cover 8 and the second blade tip cover 9 adjacent in the circumferential direction are in contact with the first blade tip cover formed at the rotor axial center of the side wall on the rotor circumferential side. The surface 10 and the second blade tip cover contact surface 11 are in contact with each other on the surfaces facing the axial direction.

  Further, of the side wall surface of the rotor blade tip cover on the rotor circumferential side, the opposed surface 12a on the blade inlet side of the first blade tip cover 8 and the second blade located on both sides in the rotor axial direction across the contact surface. Between the facing surface 13a on the blade inlet side of the tip cover 9 and between the facing surface 12b on the blade outlet side of the first blade tip cover 8 and the facing surface 13b on the blade outlet side of the second blade tip cover 9. The structure has a gap both during rotation and during non-rotation. Note that the facing surfaces 12 and 13 are surfaces facing the circumferential direction, and the positions in the rotor circumferential direction are different according to the shape of the wing portion, and have different shapes.

  That is, the first moving blade tip cover 8 and the second moving blade tip cover 9 vibrate in different directions for vibration modes in which adjacent moving blades 4 fluctuate in different phases in the circumferential direction. Friction occurs at the contact portion between the tip cover contact surface 10 and the second blade tip cover contact surface 11, and the resonance amplitude is attenuated by friction damping.

  As described above, in the conventional turbine blade tip cover shape, friction damping is applied to the circumferential vibration mode by bringing the adjacent first blade tip cover 8 and second blade tip cover 9 into contact with each other. As a result, the resonance amplitude is reduced.

  On the other hand, since there are a plurality of vibration modes to be avoided in the moving blades of the steam turbine, a structure that exhibits a damping effect for modes other than the circumferential mode is desirable. Therefore, the structure of the turbine rotor blade according to the present embodiment, which can exhibit a damping effect for a plurality of modes, will be described.

  FIG. 3 is an example showing the turbine blade structure of the present embodiment.

  As shown in FIG. 3, in this embodiment, the first blade tip cover contact surface 10 and the second blade tip cover between the first blade tip cover 8 and the second blade tip cover 9 that are adjacent to each other in the circumferential direction. A viscoelastic body 14 is installed as a damper member between the first blade tip cover facing surface 12 and the second blade tip cover facing surface 13 on both sides of the contact portion of the contact surface 11. ing.

  As a shape of the viscoelastic body 14, it is formed as a substantially rectangular parallelepiped in the present embodiment. However, the present invention is not limited to this, and any shape that can touch the opposing surface is acceptable. For example, it may be substantially spherical.

  In addition, as shown in FIG. 3, the installation method of the viscoelastic body 14 is to form the installation groove 15 in the first blade tip cover facing surfaces 12a, b and the second blade tip cover facing surfaces 13a, b. Thus, the viscoelastic body 14 is installed.

  The viscoelastic body 14 should be fixed to the surface of the first moving blade tip cover 8 facing the circumferential direction of the installation groove 15 and the surface of the second moving blade tip cover 9 facing the circumferential direction of the installation groove 15. desirable. This is because by fixing the viscoelastic body 14 to the tip covers on both sides, both the viscoelastic effect due to the compressive deformation of the viscoelastic body 14 and the effect of viscoelastic attenuation due to the extension deformation of the viscoelastic body 14 can be exhibited. is there.

  On the other hand, even when the viscoelastic body 14 is not fixed to the front end covers on both sides, the viscoelastic effect due to the compressive deformation of the viscoelastic body 14 is exhibited, so that there is a viscoelastic effect without fixing.

  As the shape of the installation groove 15, the outer ring side of the first blade tip cover 8 and the second blade tip cover 9 of the groove 15 is closed so that the viscoelastic body 14 is not scattered by centrifugal force during rotation. It needs to be structured. The advantage of installing the viscoelastic body 14 by the groove structure is advantageous in terms of maintenance because it is easy to replace the viscoelastic body 14 when the viscoelastic body 14 is worn when a structure in which the viscoelastic body 14 is not fixed is adopted.

  The viscoelastic body 14 needs to be installed on opposite surfaces on both sides of the rotor axial blade inlet side and the blade outlet side, with the first blade tip cover contact surface 10 and the second blade tip cover contact surface 11 interposed therebetween. . This is because, in the structure in which the viscoelastic body 14 is provided only on one side facing surface when resonating in the circumferential vibration mode, between the first blade tip cover 8 and the second blade tip cover 9. Since the load from the viscoelasticity 14 acts only on the one opposing surface, there is a possibility that biased stress acts on the first blade tip cover 8 and the second blade tip cover 9.

  Moreover, it is because there exists an advantage of producing the viscoelastic damping effect with respect to torsion mode by installing the viscoelastic body 14 in the opposing surface of both sides. Therefore, it is necessary to install the viscoelastic body 14 on the opposed surfaces on the axial blade inlet side and the blade outlet side with the first blade tip cover contact surface 10 and the second blade tip cover contact surface 11 interposed therebetween.

  As the shape of the viscoelastic body 14, when a groove structure is employed as in the present embodiment, when the viscoelastic body 14 is installed in the installation groove 15, it is partially between the installation groove 15 and the viscoelastic body 14. It is desirable to have a shape that creates a gap. The reason is that when a compression load is applied to the viscoelastic body 14 and there is no gap between the installation groove 15 and the viscoelastic body 14, the viscoelastic body 14 cannot be compressed and deformed, and the viscoelastic effect is reduced. This is because there is a possibility.

  In addition, the viscoelastic body 14 has the first blade tip cover contact surface 10 and the second motion when a load is applied from both sides of the first blade tip cover facing surface 12 and the second blade tip cover facing surface 13. Although it is necessary to deform so as not to hinder the frictional damping that occurs between the blade tip cover contact surfaces 11, if it is too soft, the viscoelastic effect of the viscoelastic body 14 will be reduced, and from the viewpoint of both frictional damping and viscoelastic damping. The optimum hardness is determined. Further, the viscoelastic body 14 needs to be a member having heat resistance that can withstand the heat of the vapor that is the working fluid. For example, a member formed of carbon nanotubes is conceivable.

  FIG. 4 is a diagram for explaining the first action of the present embodiment.

  FIG. 4 shows the behavior of the blade tip cover 6 when the blade 4 resonates in the circumferential vibration mode. FIG. 4 shows the behavior of the blade tip cover 6 when adjacent blades 4 vibrate in opposite phases.

  As shown in FIG. 4, when adjacent rotor blades 4 vibrate in the circumferential direction with opposite phases, the rotor blades 4 fluctuate as indicated by arrows 21. At this time, as described above with reference to FIGS. 2 and 3, in the conventional blade tip cover shape, the blade tip cover 6 of each blade 4 is in contact near the center. 22 has a structure capable of attenuating the resonance amplitude.

  In addition, in the structure using the viscoelastic body 14 as in this embodiment, when the moving blade tip cover 6 is displaced so as to press the viscoelastic body 14 from both sides, the viscoelastic body 14 is compressed and deformed. Since a viscoelastic damping force acts in the direction of the arrow indicated by, a force acts so as to attenuate the resonance amplitude.

  Further, when the moving blade tip cover 6 is displaced so as to pull the viscoelastic body 14 from both sides, the viscoelastic body 14 is stretched and deformed, and a viscoelastic damping force acts in the direction of the arrow indicated by 24, so that the resonance amplitude A force acts so as to damp.

  That is, since the viscoelastic force 23 due to compression deformation and the viscoelastic force 24 due to extension deformation act in addition to the friction damping force 22 of the conventional blade tip cover shape, the viscoelastic body 14 is installed as in this embodiment. By doing so, there is an effect that the damping force in the circumferential vibration mode can be increased.

  FIG. 4 shows the case where the adjacent rotor blades 4 vibrate in the opposite phase, but they are not necessarily intended for the vibration mode in the opposite phase. If the mode is other than the same phase, the damping force is applied. To do.

  Further, when the viscoelastic body 14 is not fixed to the first blade tip cover 8 or the second blade tip cover 9, the viscoelastic force 24 due to the extension deformation shown in FIG. Only the effect of viscoelastic force 23 is obtained.

  FIG. 5 is a diagram for explaining the second action of the present embodiment.

  FIG. 5 shows the behavior of the blade tip cover 6 when the blade 4 resonates in the torsional vibration mode. FIG. 5 shows the behavior of the blade tip cover 6 when adjacent blades 4 vibrate in opposite phases.

  As shown in FIG. 5, when adjacent moving blades 4 vibrate in opposite phases, the moving blades change in the direction of the arrow indicated by 21. In that case, as shown in FIG. 5, the gap between the opposing surfaces of the adjacent blade tip covers 6 has a portion that becomes smaller and a portion that becomes larger.

  In the structure using the viscoelastic body 14 between the adjacent blade tip covers 6 as in the present embodiment, when the gap between the opposing surfaces of the adjacent blade tip covers 6 changes in the direction of decreasing, the viscosity is changed. Since the elastic body 14 is pressed from both sides, the viscoelastic body 14 is compressed and deformed, and a viscoelastic damping force acts in the direction of the arrow indicated by 23, so that a force acts to attenuate the resonance amplitude.

  Further, when the gap between the opposing surfaces of the adjacent blade tip covers 6 fluctuates greatly in the direction, the viscoelastic body 14 is pulled from both sides, so that the viscoelastic body 14 expands and deforms in the direction of the arrow indicated by 24. Since the viscoelastic damping force acts, the force acts so as to attenuate the resonance amplitude.

  That is, in addition to the effect of increasing the damping force in the circumferential vibration mode shown in FIG. 4, the damping force also acts on the torsional vibration mode.

When the viscoelastic body 14 is not fixed to the first blade tip cover 8 or the second blade tip cover 9, the viscoelastic force 24 due to the extension deformation shown in FIG. Only the effect of viscoelastic force 23 is obtained.
Therefore, according to the present embodiment, not only the damping force in the circumferential vibration mode is increased, but also the damping force acts on the torsional vibration mode, so that the damping effect can be exerted on a plurality of vibration modes with the same structure, There is an effect that the resonance amplitude can be reduced.

  Next, a second embodiment of the present invention will be described.

  FIG. 6 is a diagram illustrating an example in which a viscoelastic body is installed as a sheet shape. Here, the same components as those described in the first embodiment are denoted by the same reference numerals, description thereof is omitted, and portions different from those in the first embodiment are described.

  In FIG. 6, as in the first embodiment, the first blade tip cover 8 and the second blade tip cover 9 that are adjacent in the circumferential direction are connected to the first blade tip cover contact surface 10 at the center in the rotor axial direction. A structure in which the contact portions of the second blade tip cover contact surface 11 are in contact with each other on the surfaces facing the axial direction is intended.

  Note that the facing surface 12 of the first blade tip cover and the facing surface 13 of the second blade tip cover do not contact each other during rotation and non-rotation.

  In FIG. 6, the first blade tip cover contact surface 10 and the second blade tip cover contact surface 11 in the vicinity of the center are in contact with each other on the surfaces facing the axial direction. The friction damping effect of the conventional blade tip cover shape can be maintained against the circumferential vibration mode.

  The difference from the first embodiment is the shape and installation method of the viscoelastic body 14. In this embodiment, the shape of the viscoelastic body 14 is a sheet shape, and the installation method is a structure in which the viscoelastic body 14 is adhered and fixed to the opposing surface 12 of the first blade tip cover and the opposing surface 13 of the second blade tip cover. Yes.

  On the other hand, the viscoelastic body 14 may be structured to be fixed to either the facing surface 12 of the first blade tip cover or the facing surface 13 of the second blade tip cover. This is the same as in the above-described embodiment, and is a difference in whether or not to consider the viscoelastic effect due to the elongation deformation of the viscoelastic body 14.

  In the first embodiment, the viscoelastic body 14 has a structure in which the groove 15 is provided on the facing surface 12 of the first blade tip cover and the facing surface 13 of the second blade tip cover. Then, since the groove 15 is not processed, the viscoelastic body 14 is directly attached to the opposing surface 12 of the first moving blade tip cover or the opposing surface 14 of the second moving blade tip cover. There is no need for processing, and there is an advantage that the manufacturing cost can be reduced as compared with the first embodiment.

  In addition, when the moving blade 4 vibrates in the circumferential direction and the torsional vibration mode, the surface where the viscoelastic body 14 contacts between the facing surface 12 of the first moving blade tip cover and the facing surface 13 of the second moving blade tip cover. Since the force acts on the viscoelastic body 14 in a wider area, there is an advantage that the damping force increases.

  Next, a third embodiment of the present invention will be described.

  FIG. 7 is a view showing a turbine rotor blade structure according to a third embodiment of the present invention. Here, the same components as those described in the first embodiment are denoted by the same reference numerals, description thereof is omitted, and portions different from those in the first embodiment are described.

  In FIG. 7, as in the first embodiment, the first blade tip cover 8 and the second blade tip cover 9 that are adjacent in the circumferential direction are arranged so that the first blade tip cover contact surface 10 and the first blade tip cover contact surface 10 near the center in the axial direction. 2 A structure in which the contact portions of the blade tip cover contact surface 11 are in contact with each other on the surfaces facing the axial direction.

  Note that the facing surface 12 of the first blade tip cover and the facing surface 13 of the second blade tip cover do not contact each other during rotation and non-rotation.

  The difference from the first embodiment is the installation method of the viscoelastic body 14. In this embodiment, the viscoelastic body 14 is fixed to the surface of the groove 15 facing the axial direction. By fixing the viscoelastic body 14 on the surface of the groove 15 facing the axial direction, the vibration is generated in a direction (axial direction) in which a gap is generated between the first blade tip cover contact surface 10 and the second blade tip cover contact surface 11. In this case, there is an effect that the viscoelastic body 14 undergoes shear deformation and a damping force is generated by the viscoelastic force due to the shear deformation.

  The viscoelastic body 14 is not necessarily fixed to all the axially facing surfaces of the groove 15 of the first blade tip cover 8 and the groove 15 of the second blade tip cover 9. Even if only the surface of the tip cover 8 facing the upstream side in the axial direction of the groove 15 and the surface of the second rotor blade tip cover 9 facing the downstream side in the axial direction of the groove 15 are fixed, the viscoelastic body 14 undergoes shear deformation. Therefore, the same effect is exhibited.

  As mentioned above, although the Example of this invention was described, this invention is not limited to an above-described Example, Various modifications are included. For example, in FIG. 3 of the first embodiment, the blade tip cover shape that is in contact with the facing surface facing in the axial direction is targeted, but the present invention is not necessarily limited to the blade tip cover that is in contact with the facing surface facing in the axial direction. It does not cover only the cover shape. For example, a blade tip cover shape in which the contact surface faces the circumferential direction or the oblique direction may be used. In short, there is no problem if viscoelastic bodies can be installed at both ends across the contact surface.

  In the embodiments of the present invention, the diaphragm-structured steam turbine has been described as an example. However, the present invention is not limited to the diaphragm-structured steam turbine. It is done.

DESCRIPTION OF SYMBOLS 1 Diaphragm outer ring | wheel 2 Diaphragm inner ring | wheel 3 Stator blade 4 Rotor blade 5 Rotor 6 Rotor blade tip cover 8 First blade tip cover 9 Second blade tip cover 10 First blade tip cover contact surface 11 Second blade tip cover contact Surface 12 First blade tip cover facing surface 13 Second blade tip cover facing surface 14 Viscoelastic body 15 Installation groove

Claims (12)

A turbine rotor blade row assembly in which a plurality of turbine rotor blades having a blade portion and a rotor blade tip cover provided at the tip of the blade portion are fixed to a rotor of a turbomachine in the rotor circumferential direction,
A contact surface that is formed on a part of the rotor circumferential side wall surface of the blade tip cover and that contacts the adjacent blade tip cover;
A first damping member provided in a gap portion on the rotor axial direction blade inlet side with respect to the contact surface among the gap portions formed between adjacent blade tip covers;
A turbine comprising: a second damping member provided in a gap portion on the rotor axial direction blade outlet side with respect to the contact surface in a gap portion formed between adjacent blade tip covers. Rotor row assembly. The turbine rotor cascade assembly according to claim 1,
The contact surface is a surface facing the rotor axial direction, located in the rotor axial direction central portion of the rotor circumferential side wall surface,
Of the rotor circumferential side walls of the rotor blade tip cover, the wall surface on which the first and second damping members are brought into contact with each other is a surface facing the rotor circumferential direction. Assembly. The turbine rotor cascade assembly according to claim 2, wherein
The rotor blade tip cover is formed on the rotor circumferential side wall surface on the rotor axial blade inlet side with respect to the contact surface, and a concave first installation groove for installing the first vibration damping member; A turbine blade having a concave second installation groove formed on the rotor circumferential side wall surface on the rotor axial blade outlet side with respect to the contact surface, for installing the second vibration damping member. Row assembly. The turbine rotor cascade assembly according to claim 3, wherein
The first damping member is in contact with a surface of the first installation groove facing the rotor circumferential direction, and the second damping member is oriented to the rotor circumferential direction of the second installation groove. A turbine rotor cascade assembly characterized by being in contact with a surface. The turbine rotor cascade assembly according to claim 3, wherein
The first damping member is in contact with the surface of the first installation groove facing the rotor axial direction, and the second damping member is oriented to the rotor axial direction of the second installation groove. A turbine rotor cascade assembly characterized by being in contact with a surface. The turbine rotor cascade assembly according to claim 3, wherein
The first damping member includes a surface facing the rotor axial blade inlet side of the installation groove formed on one cover of the adjacent blade tip cover, and the opposing surface formed on the other cover. It is in contact with the surface facing the rotor axial blade exit side of the installation groove,
The second vibration damping member has a surface facing the rotor axial blade inlet side of the installation groove formed in one cover of the adjacent blade tip cover, and the opposite surface formed in the other cover. A turbine rotor cascade assembly characterized by being in contact with a surface of the installation groove facing the rotor axial blade outlet side. The turbine rotor cascade assembly according to claim 2, wherein
The turbine blade cascade assembly according to claim 1, wherein the first and second damping members are formed in a sheet shape and are affixed to a rotor circumferential side wall surface of the blade tip cover. A turbine rotor cascade assembly according to any one of claims 1 to 7,
The turbine rotor cascade assembly according to claim 1, wherein the first and second damping members are viscoelastic bodies. The turbine rotor cascade assembly according to claim 8, wherein
The turbine rotor cascade assembly according to claim 1, wherein the first and second damping members have heat resistance against heat of a working fluid of the turbomachine. A turbine rotor cascade assembly according to claim 8 or 9, wherein
The turbine rotor cascade assembly, wherein the first and second damping members are formed of carbon nanotubes. A turbine rotor cascade assembly according to any one of claims 1 to 10,
The turbine rotor cascade assembly according to claim 1, wherein the first and second damping members have a hardness capable of being deformed to such an extent that the friction damping generated between the contact surfaces of the adjacent rotor blade tip covers is not hindered.   A steam turbine facility comprising the turbine rotor cascade assembly according to any one of claims 1 to 11.