JP2015148284A - Liquid damper and rotary machine blade including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid damper which stabilizes damping of the damper thereby stably operating a member for a rotary machine and enabling easy vibration prediction.SOLUTION: A rotary machine blade includes a liquid damper 10 used in an integral shroud and including a housing 11, in which a storage space is formed, and a viscous fluid or a visco-elastic fluid 12 which is stored in the storage space and flowable. A beam-like protruding piece 13 which protrudes from an inner surface of the housing 11 and has flexibility is provided at the housing 11 of the liquid damper 10. Multiple orifices 13a composed of fine through holes are formed in the beam-like protruding piece 13.

Description

  The present invention relates to a liquid damper and a rotary machine blade provided with the same.

  Conventionally, in order to reduce the weight of a turbine, a turbine blade having a hollow structure in which a hollow portion is defined by respective back surfaces of an abdominal side portion and a back side portion is used. In such turbine blades, shroud dampers, leaf spring dampers, and seal pin dampers are employed as techniques for suppressing vibrations in order to reduce the vibration response level of the turbine blades (see, for example, Patent Document 1). These dampers are installed inside the blades or between the blades, and have a damping effect due to friction because the dampers and the blades come into contact at the time of resonance.

JP 2010-203435 A

However, in conventional turbine blades that employ friction damping, the contact surface between the blade and the damper is not stable, so the blade vibration characteristics are not stable and vibration cannot be predicted easily. It was. Therefore, there has been a problem that the operation of the turbine including the turbine blades becomes unstable.
In addition, when the turbine is operated for a long time, wear and adhesion occur between the blades and the damper, and as described above, the state of the contact surface is not stable, so there is room for improvement in that respect. there were.

  The present invention has been made in view of the above-described problems. By stabilizing the damping of the damper, the rotary machine member can be stably operated and vibration prediction can be easily performed. An object of the present invention is to provide a liquid damper and a rotary machine blade provided with the same.

  In order to achieve the above object, a liquid damper according to the present invention is a liquid damper that is disposed between a pair of members for a rotary machine that vibrate relative to each other, and is provided in an accommodation space formed inside the member for a rotary machine. It is characterized by having a viscous fluid or viscoelastic fluid that is contained and can flow.

  Further, a rotary machine blade provided with a liquid damper according to the present invention is a rotary machine blade provided with the liquid damper described above, wherein the rotary machine member is a shroud provided at the tip of the blade, and the liquid damper includes: It is provided in the contact surface between the said adjacent shrouds.

  In the present invention, vibration generated in a rotating machine member such as a shroud can be attenuated by a liquid damper containing a viscous fluid or a viscoelastic fluid, and an effect of reducing vibration stress can be obtained. That is, when a pair of rotating machine members that vibrate in relative contact with each other by resonance, an impact force is also applied to the liquid damper provided in these rotating machine members, and the internal viscous fluid or viscoelastic fluid is also excited. At this time, when the viscous fluid or the viscoelastic fluid is excited, the kinetic energy of the fluid is converted into thermal energy, which can reduce the vibration of the rotating machine member and exhibit a damping effect. Become.

  As described above, in the present invention, since the vibration characteristics related to the damping of the liquid damper that suppresses the vibration of the rotating machine member are stable, the vibration prediction can be performed easily and more accurately, and aged such as wear. It is possible to cope with the deterioration, and it is possible to stably operate a power plant including a rotating machine member.

  Further, the liquid damper according to the present invention includes a housing that can be accommodated in the housing space and forms a closed space, and the viscous fluid or the viscoelastic fluid housed in the housing, and an inner surface of the housing It is preferable that a beam-like projecting piece having flexibility is protruded.

In this case, since the beam-like protruding piece having flexibility is arranged inside the viscous fluid or the viscoelastic fluid, and the beam-like protruding piece is flexibly shaken by vibration, the effect is relatively exhibited in a low frequency region. Compared with the case where only a viscous fluid or a viscoelastic fluid is provided, the vibration reduction effect in the high frequency region can be exhibited, and the frequency region can be widened. Therefore, there exists an advantage suitable for use of the gas turbine which becomes especially a high frequency area | region.
Further, in the present invention, the liquid damper can be a housing type and can be easily configured to be detachable. By making the liquid damper detachable as described above, there is an advantage that it can be appropriately replaced when adjusting the damping effect or during maintenance.

  In the liquid damper according to the present invention, it is preferable that the natural frequency of the beam-like protruding piece is set in accordance with the natural frequency of the rotating machine member.

  In this case, by matching the resonance point (natural frequency) of the beam-like protruding piece with the resonance point of a rotating machine member such as a shroud, the liquid damper can function as a dynamic vibration absorber. The vibration of the member can be effectively reduced.

  In the liquid damper according to the present invention, it is preferable that a plurality of the beam-like projecting pieces are provided.

  In this case, since there is not usually one vibration mode to be detuned at the time of design, a plurality of beam-like projecting pieces at each resonance point can be installed to broaden the vibration of rotating machine members. Can be reduced in a wide frequency range, and the function of the dynamic vibration absorber can be exhibited more effectively. In addition, it is possible to change the damping coefficient by changing the material, thickness dimension, length dimension, etc. of each of the plurality of beam-like protruding pieces. Can be arranged.

  In the liquid damper according to the present invention, it is preferable that the beam-like projecting piece is formed with a plurality of orifices composed of minute through holes.

  In the present invention, when the viscous fluid or viscoelastic fluid passes through the plurality of orifices formed in the beam-like protruding piece, the vibration energy of the rotating machine member can be converted into the kinetic energy by the orifice, and the damping is further increased. Since the effect is obtained, the function of the dynamic vibration absorber covering a wider frequency range can be exhibited.

  In the liquid damper according to the present invention, it is preferable that the plurality of orifices pass through in a rotational circumferential direction of the rotary machine member.

  In this case, vibrations in the rotational circumferential direction that are likely to occur with the rotation of the rotating machine member can be effectively damped by the plurality of orifices.

  According to the liquid damper of the present invention and the rotary machine blade including the same, it is possible to stably operate the rotary machine member and to easily perform vibration prediction by stabilizing the damping of the damper. There is an effect that can.

It is a side view showing a schematic structure of a turbine rotor blade by an embodiment of the invention. It is the figure which looked at a pair of adjacent integral shrouds from the outside in the radial direction. It is an expansion perspective view of an integral shroud, and is a figure showing a state where a liquid damper has come off. It is sectional drawing which looked at the liquid damper from one direction. It is a front view which shows the beam provided in the liquid damper shown in FIG. FIG. 5 is a cross-sectional view taken along line AA shown in FIG. 4 and is a cross-sectional view of the liquid damper as viewed from the other direction. It is a figure which shows the frequency response curve at the time of blade resonance in a liquid damper. It is sectional drawing which shows the structure of the liquid damper by a 1st modification. (A)-(c) is sectional drawing which shows the liquid damper by a 2nd modification.

  Hereinafter, a liquid damper according to an embodiment of the present invention and a rotary machine blade provided with the same will be described with reference to the drawings. Such an embodiment shows one aspect of the present invention, and is not intended to limit the present invention, and can be arbitrarily changed within the scope of the technical idea of the present invention.

  As shown in FIG. 1, the turbine to which the moving blade 1 (rotary machine blade) of the present embodiment is applied is used in a power plant or the like. For example, such a steam plant includes a steam generator that generates high-pressure steam, a high-pressure steam turbine that is directly supplied with high-pressure steam from the steam generator, and moisture content of steam from the steam generator and steam turbine. A moisture separation heater for separating and heating the steam and a low pressure steam turbine (hereinafter referred to as a steam turbine) to which low pressure steam is supplied from the moisture separation heater are provided.

  In the steam turbine described above, steam from the moisture separator heater is supplied to the steam inlet, and flows in the steam passage formed in the steam turbine along the axial direction of the rotor shaft. In the steam passage, rotating blades 1 and stationary blades, which are rotating mechanical blades, are alternately arranged. The steam turbine generates kinetic energy by pressure drop in the stationary blades, and this is converted into rotational torque by the moving blades 1. It has been converted. Here, the radial direction of the rotating shaft of the rotor is indicated by an arrow R, and the rotating direction (circumferential direction) around the rotating shaft is indicated by an arrow X.

  Reference numerals 2 (2A, 2B) in FIGS. 1 and 2 indicate an integral shroud (rotary machine member, shroud) provided at the blade tip 3a of the blade portion 3 (3A, 3B) in the rotor blade 1. FIG. In these integral shrouds 2A and 2B, centrifugal force F acts together with the moving blade 1 by the rotational motion of the steam turbine.

Liquid dampers 10 are respectively provided on contact surfaces (side surfaces 2a, 2b) between adjacent integral shrouds 2A, 2B provided at blade tips 3a of adjacent blade portions 3A, 3B.
As shown in FIGS. 2 and 3, one of the integral shrouds 2A and 2B has a first side surface 2a (one side surface in the circumferential direction X of the rotating shaft) and another second side surface 2b (the circumferential direction X of the rotating shaft). On the side facing the opposite side of the first side surface 2a, a box-shaped first recess 21 and second recess 22 (accommodating space) for accommodating the liquid damper 10 are formed at positions corresponding to the first side surface 2a. .

  As shown in FIGS. 4 to 6, the liquid damper 10 includes a housing 11 that is detachably mounted in the first recess 21 and the second recess 22, and a flowable viscosity that is accommodated in the housing 11. Fluid or viscoelastic fluid 12.

  The housing 11 is made of a heat-resistant material such as Ni alloy or titanium, and forms a liquid-tight closed space by six-walled bodies. Here, FIGS. 4 and 6 show a state in which the centrifugal force F acts on the liquid damper 10 toward the upper side of the drawing.

  Examples of the viscous fluid or the viscoelastic fluid 12 accommodated in the housing 11 include lead (liquid), polymer liquid, and the like, and are selected from the temperature at the mounting position of the liquid damper 10. 4 and 6 show an example in which lead liquefied in a high temperature region of about 300 ° C. is used as the viscous fluid or the viscoelastic fluid 12, for example. In this case, even when the housing 11 is filled with solid (not shown) at room temperature, it liquefies at a high temperature such as during turbine operation.

  On the inner surface of one wall body (first wall body 11a) of the housing 11, a plate-like beam-shaped projecting piece 13 having an orifice structure and having flexibility is projected. The beam-shaped projecting piece 13 is formed of, for example, a material such as titanium or Ni alloy, and the projecting direction at the center position in the width direction of the first wall 11a is the direction in which the centrifugal force F acts (direction of arrow Y). It is provided for. The height dimension H (the length dimension in the radial direction R) of the beam-shaped projecting piece 13 can be set arbitrarily, but here the projecting end 13b is a second surface facing the first wall 11a of the housing 11. The height is set close to the wall 11b.

  A plurality of (six in FIG. 5) orifices 13a made of minute through holes are formed in the beam-like projecting piece 13 in the thickness direction, and an orifice structure having a damping function is configured by these orifices 13a. Yes. The orifice 13 a penetrates in the circumferential direction X of the integral shroud 2.

  The natural frequency of the beam-like protruding piece 13 having such an orifice 13 a is set according to the natural frequency of the integral shroud 2. That is, by making the resonance point of the beam-like protruding piece 13 coincide with the resonance point of the integral shroud 2, it can function as a dynamic vibration absorber, and the vibration reduction effect is not exhibited mainly in the low frequency region. The frequency range can be expanded.

Next, the operation of the moving blade 1 having the above-described configuration will be specifically described based on the drawings.
As shown in FIGS. 2 and 3, in the present embodiment, the vibration generated in the integral shroud 2 can be damped by the liquid damper 10 containing the viscous fluid or the viscoelastic fluid 12, and the effect of reducing the vibration stress can be obtained. Can be obtained. That is, when the pair of integral shrouds 2A, 2B that vibrate relative to each other comes into contact by resonance, an impact force is also applied to the liquid damper 10 provided in these integral shrouds 2A, 2B, as shown in FIGS. The internal viscous fluid or viscoelastic fluid 12 is also excited. At this time, when the viscous fluid or the viscoelastic fluid 12 is excited, the kinetic energy of the fluid is converted into thermal energy, thereby reducing the vibration of the integral shroud 2 and exhibiting a damping effect. become.

  As described above, since the vibration characteristics related to the damping of the liquid damper 10 that suppresses the vibration of the integral shroud 2 are stabilized, the vibration prediction can be performed easily and more accurately, and the deterioration due to aging such as wear can be prevented. This makes it possible to stably operate a power plant equipped with the integral shroud 2.

  In addition, since the beam-like protruding piece 13 having flexibility is disposed inside the viscous fluid or viscoelastic fluid 12 and the beam-like protruding piece 13 can be flexibly shaken by vibration, an effect is exhibited in a relatively low frequency region. Compared with the case where only the viscous fluid or the viscoelastic fluid 12 is provided, the vibration reduction effect in the high frequency region can be exhibited, and the frequency region can be widened. Therefore, there exists an advantage suitable for use of the gas turbine which becomes especially a high frequency area | region.

  In the present embodiment, since the liquid damper 10 includes the housing 11, the liquid damper 10 can be easily attached to and detached from the integral shroud 2. Thus, by making the liquid damper 10 detachable, there is an advantage that it can be replaced as appropriate when adjusting the damping effect or during maintenance.

  Further, in the present embodiment, by making the resonance point (natural frequency) of the beam-like protruding piece 13 coincide with the resonance point of the integral shroud 2, the liquid damper 10 can function as a dynamic vibration absorber. The vibration of the rush shroud 2 can be effectively reduced.

  Further, in the present embodiment, the orifice 13a is formed in the beam-like protruding piece 13, and therefore the viscous fluid or viscoelastic fluid 12 passes through the orifice 13a formed in the beam-like protruding piece 13, so that the integral Since the vibration energy of the shroud 2 can be converted into kinetic energy by the orifice 13a and a higher damping effect can be obtained, the function of the dynamic vibration absorber covering a wider frequency range can be exhibited.

  Further, by providing the orifice 13a so as to penetrate in the circumferential direction X of the integral shroud 2, vibration in the circumferential direction X that is likely to occur as the integral shroud 2 rotates is effectively caused by the orifice 13a. Can be attenuated. The penetrating direction of the orifice 13a is not limited to the circumferential direction X, and may be a radial direction or a rotor axial direction.

Here, the effect of the moving blade 1 of this Embodiment is demonstrated using FIG.
The frequency response curve at the time of blade resonance shown in FIG. 7 is an example of a result obtained by replacing the blade with a beam model and analyzing the case where the target mode is the bending primary and the liquid damper is provided or not provided. The liquid damper was assumed to be an orifice of lead (liquid) and a beam structure (beam-like protruding piece). The mass of the liquid damper is omitted because it is smaller than the blade. As a result, it can be confirmed that the blade having the liquid damper can obtain an amplitude reduction effect of 40% at the maximum as compared with the blade having no liquid damper.

  In the liquid damper according to the present embodiment described above and the rotary machine blade including the damper, the damping of the damper can be stabilized, so that the integral shroud 2 can be stably operated and vibration prediction can be easily performed. There is an effect that can be performed.

  The liquid damper according to the present invention and the embodiment of the rotary machine blade including the liquid damper have been described above. However, the present invention is not limited to the above-described embodiment, and may be changed as appropriate without departing from the scope of the present invention. Is possible.

For example, in the present embodiment, the integral shroud 2 of the rotor blade 1 is an application target of the liquid damper 13, but the present invention is not limited to this, and other rotary machine members may be applied.
In this embodiment, an example in which a steam turbine is an application target of a liquid damper is shown, but a gas turbine may be used.

  Further, the beam-like protruding piece 13 may be omitted as the liquid damper, or the beam-like protruding piece 13 in which the orifice 13a is not formed can be used.

Note that the material, thickness dimension, length dimension, and projecting direction of the beam-like projecting piece 13 provided in the liquid damper 10 can be changed as appropriate.
For example, as in the liquid damper 10B of the first modification shown in FIG. 8, it is possible to project three beam-like projecting pieces 13 (13A, 13B, 13C) having different heights H in parallel and spaced from each other. It is. Of the beam-like protruding pieces shown in FIG. 8, an orifice 13a is formed in the beam-like protruding piece 13A having the highest height H and the beam-like protruding piece 13B having the second highest height, and the beam-like protruding piece having the lowest height. No orifice is provided in 13C. When a plurality of beam-like projecting pieces 13 are provided in the liquid damper in this way, the vibration mode to be detuned at the time of design is not usually one. Therefore, a plurality of beam-like projecting pieces 13 at each resonance point are provided. By installing, the vibration of the rotary machine member can be reduced in a wide frequency range, and the function of the dynamic vibration absorber can be more effectively exhibited.
In addition, the damping coefficient can be changed by changing the material, thickness dimension, length dimension, projecting direction, etc. of each of the plurality of beam-like projecting pieces. A protruding piece can be arranged.

  Further, like the liquid damper 10C of the second modified example shown in FIGS. 9A to 9C, the first beam-like protruding piece 13D and the second beam-like protruding piece 13E are provided so that the protruding directions are different. It may be. Here, in FIG. 9A, the viscous fluid or the viscoelastic fluid 12 is omitted. That is, the first beam-shaped protruding piece 13D is suspended from the first wall 11a of the housing 11, and the second beam-shaped protruding piece 13E is suspended from the third wall 11c adjacent to the first wall 11a. The first beam-like projecting piece 13D and the second beam-like projecting piece 13E are projected in directions orthogonal to each other. FIG. 9B is a diagram in which the centrifugal force F acts from the lower side to the upper side of the paper surface, and FIG. 9C is a diagram in which the centrifugal force F acts from the left side to the right side of the paper surface. It has become.

  In addition, it is possible to appropriately replace the constituent elements in the above-described embodiments with well-known constituent elements without departing from the spirit of the present invention, and the above-described embodiments may be appropriately combined.

1, 1A, 1B Rotor blade (rotary machine blade)
2, 2A, 2B Integral shroud (member for rotating machinery, shroud)
3, 3A, 3B Blade 3a Blade tip 4 Platform 5 Blade root 10, 10A, 10B, 10C Liquid damper 11 Housing 12 Viscous fluid or viscoelastic fluid 13, 13A-13E Beam-like projecting piece 13a Orifice 21 First recess 22 Second recess X Circumferential direction

Claims (7)

A liquid damper disposed between a pair of rotary machine members that vibrate relatively,
A liquid damper having a viscous fluid or a viscoelastic fluid which is accommodated in a housing space formed inside the rotary machine member and which can flow. A housing that can be housed in the housing space and forms a closed space;
The viscous fluid or viscoelastic fluid housed in the housing;
With
The liquid damper according to claim 1, wherein a flexible beam-shaped projecting piece projects from the inner surface of the housing.   The liquid damper according to claim 2, wherein a natural frequency of the beam-shaped protruding piece is set in accordance with a natural frequency of the rotating machine member.   The liquid damper according to claim 2, wherein a plurality of the beam-like protruding pieces are provided.   The liquid damper according to any one of claims 2 to 4, wherein a plurality of orifices including minute through holes are formed in the beam-like projecting piece.   The liquid damper according to claim 5, wherein the plurality of orifices penetrates in a rotation circumferential direction of the rotating machine member. A rotary machine blade including the liquid damper according to any one of claims 1 to 6,
The rotating machine member is a shroud provided at a blade tip;
The rotary machine blade having a liquid damper, wherein the liquid damper is provided on a contact surface between the adjacent shrouds.

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