JP2009085256A - Seal device for rotary fluid machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a seal device for a rotary fluid machine capable of dispensing with a seal fin position control device, capable of reducing excess force generated when a seal fin is abutted to a rotating body side or a stationary body side, and exhibiting enhanced reliability and performance. <P>SOLUTION: In the seal device for the rotary fluid machine wherein the seal fin is arranged in a gap between a rotor and a stator, the seal fin includes a joint part b at least in one part, and a seal fin end c is movable from a position tilted to an upstream side of working fluid of the rotary fluid machine to the upstream side of the working fluid around the joint part b by abutting of the seal fin and the rotor f. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a sealing device for a rotary fluid machine.

  The shape of sealing devices used in rotating fluid machines has been improved in many ways as one of the methods aiming at high efficiency.

  The seal fin has a large gap adjusted in advance so as not to come into contact with each other in consideration of the difference in thermal expansion between the rotating side and the stationary side when a rotating fluid machine such as a turbine rotates or stops. The leakage loss increases due to this gap during steady operation, leading to a decrease in performance. An example of a structure that can ensure reliability even when both are in contact with each other is, for example, a honeycomb seal described in JP-A-11-44201.

  On the other hand, there is an ACC (Active Clearance Control) seal that automatically adjusts the gap between the seal fins. This is to prevent contact by controlling the position of the seal fin in accordance with a series of movements from start to stop of the turbine, and to improve the performance by making the gap as small as possible. There are those described in Kai 2000-97350.

JP-A-11-44201 JP 2000-97350 A

  When the rotating side and the stationary side of the turbine come into contact with each other, such as a honeycomb seal, mutual reliability is deteriorated. Moreover, it is necessary to automatically adjust the gap between the two, particularly when the turbine is started and stopped. However, the control for automatically adjusting the position of the seal fin is complicated and not easy.

  Accordingly, an object of the present invention is to provide a rotary fluid machine that does not require a seal fin position control device, reduces excessive force generated when the seal fin contacts the rotating body side or the stationary body side, and improves reliability and performance. It is in providing a sealing device.

  To achieve the above object, the present invention provides a sealing device for a rotary fluid machine in which a seal fin is disposed in a gap between a rotor and a stator, wherein the seal fin is attached to the rotor or the stator, and at least one of the seal fins is attached. There is a joint portion at a location, and the contact of the working fluid from the position where the tip of the sealing fin is inclined toward the upstream side of the working fluid of the rotary fluid machine by the contact between the seal fin and the rotor or the stator. The seal fin tip portion is configured to be movable on the upstream side.

According to the present invention, there is no need for a seal fin position control device, the excessive force generated when the seal fin comes into contact with the rotating body side or the stationary body side is reduced, and the seal of the rotating fluid machine is improved in reliability and performance. An apparatus can be provided.

The sealing device for a rotary fluid machine of the present invention can be applied to a steam turbine, a gas turbine, or the like. In the following description, as an example, an embodiment when applied to a steam turbine will be described.

  FIG. 1 is a schematic sectional view showing a first embodiment of a sealing device according to the present invention. The seal fins according to the present embodiment are arranged along the steam flow direction Y. The seal fin is formed by a fixed part a of the fin, a tip part c, and a joint part b connecting the fixed part a and the tip part c, and the fixed part a is incorporated into the stator d via a packing ring e or the like. The front end portion c of the seal fin is positioned so as to face the rotor f in the radial direction R through a certain gap, and the front end portion c of the seal fin is inclined to the lower side in the radial direction on the upstream side of the working fluid. It can move.

  2 and 3 are modifications of the first embodiment shown in FIG. 1 and are schematic cross-sectional views as seen from the rotational direction. In addition, the same code | symbol is attached | subjected to the part which is the same as the component of 1st embodiment, or a corresponding part.

  In the configuration shown in FIG. 2, a fixing portion a of a seal fin having a joint portion b and a fixing portion a ′ having no joint portion b are incorporated into a stator d via a packing ring e or the like. . In the configuration shown in FIG. 3, seal fins are installed at positions facing the cover f1 of the turbine rotor blade provided on the rotor f.

  1, 2, and 3, when the radial gap between the rotor f and the tip end portion c of the seal fin becomes narrower and the rotor f and the tip end portion c of the seal fin approach each other than the set gap, the rotor f And the tip c are in contact with each other. At this time, in the present embodiment, the front end portion c of the seal fin is rotated around the joint portion b in a direction opposite to the flow of the working fluid. For this reason, the frictional force generated between the rotor f is reduced as compared with the seal fin without the joint b, and the wear generated on the surface of the rotor f and the damage generated on the tip c of the seal fin can be reduced. Depending on the degree of wear and damage, the present embodiment can reduce the radial gap between the rotor f and the tip portion c of the seal fin as compared with the case where the seal fin without the joint portion b is used. Leakage loss can be reduced and turbine performance can be improved.

  Next, another embodiment of the present invention will be described with reference to FIGS.

  FIG. 4 is a schematic sectional view showing the second embodiment. The difference between this embodiment and the first embodiment described above is that the rotor f has a convex portion g (or a concave portion) on its surface. The tip portion c of the seal fin is positioned so as to face the seal fin side surface g1 of the convex portion g of the rotor in the flow direction Y through a certain gap, and the tip portion c of the seal fin is located on the upstream side of the working fluid. It can be moved at a position inclined downward in the radial direction.

  In the configuration shown in FIG. 4, when the gap in the flow direction between the surface g1 and the tip end portion c of the seal fin becomes narrower and the surface g1 and the tip end portion c of the seal fin approach each other than the set gap, the surface g1 contacts the tip portion c. To do. At this time, the tip portion c of the seal fin rotates in the direction of the flow of the working fluid around the joint portion b, so that the frictional force generated with the rotor f is reduced compared to the seal fin without the joint portion b, In addition, it is possible to reduce the wear generated on the surface of the structure f and the damage generated on the tip portion c of the seal fin. Depending on the degree of wear and damage, the present embodiment can reduce the flow direction gap between the rotor f and the tip end portion c of the seal fin as compared with the case where the seal fin without the joint portion b is used. The shaft length can be shortened or the number of seal fins of the seal device can be increased.

  FIG. 5 is a schematic sectional view showing the third embodiment. The difference between the present embodiment and the second embodiment is that the tip end portion c can be moved at a position tilted radially upward (outward) on the upstream side of the working fluid. That is, in the present embodiment, the joint portion b of the seal fin is disposed in the concave space formed by the convex portion g on the surface of the rotor f.

  In the embodiment of FIG. 5, when the surface g1 comes into contact with the tip portion c of the seal fin, the tip portion c rotates around the joint portion b in the direction of the working fluid flow. As a result, the frictional force generated with the rotor f is reduced as compared with the seal fin without the joint portion b, and the wear generated on the surface of the rotor f and the damage generated on the tip portion c of the seal fin can be reduced.

  FIG. 6 is a modified example of the third embodiment, and is a schematic configuration cross section viewed from the rotation direction. In addition, the same code | symbol is attached | subjected to the part which is the same as the component of 3rd embodiment, or respond | corresponds. The difference from the above-described third embodiment is that a recess h is held on the surface of the rotor f. The front end portion c of the seal fin is positioned so as to face the seal fin side surface h1 of the recess h of the rotor f in the flow direction Y through a certain gap, and the front end portion c is the upper side in the radial direction on the upstream side of the working fluid. It can be moved at a tilted position.

  The flow direction gap between the surface h1 and the seal tip portion c becomes narrow, and when the surface h1 and the seal tip portion c come closer than the set gap, the surface h1 comes into contact with the seal fin tip portion c. At this time, the tip end portion c of the seal fin rotates around the joint portion b to the opposite side of the seal fin fixing portion, so that the frictional force generated between the seal fin and the rotor f can be reduced as compared with a seal fin without the joint portion b.

  FIG. 7 is a schematic sectional view showing the fourth embodiment. In addition, the same code | symbol is attached | subjected to the part which is the same as the component of 1st embodiment, or a corresponding part. In this embodiment, the sealing fin fixing portion a of the sealing device is provided on the rotating body side. Note that the fixed portion a may be attached to the rotor f via a packing ring or the like, or may be directly incorporated into the rotor f.

  FIG. 8 is a schematic sectional view showing the fifth embodiment. In addition, the same code | symbol is attached | subjected to the part which is the same as the component of 4th embodiment, or a corresponding part. The difference from the fourth embodiment described above is that the stator d has a convex portion g (or a concave portion) on the surface. As in the fourth embodiment, the seal fin fixing portion a is directly inserted into the rotor via a packing ring or the like.

  FIG. 9 is a schematic sectional view showing the sixth embodiment. The difference from the fifth embodiment described above is that the tip end portion c can be moved at a position tilted radially downward (inward) on the upstream side of the working fluid. That is, in this embodiment, the joint portion b of the seal fin is disposed in the concave space formed by the convex portion g on the surface of the stator d.

  FIG. 10 is a modified example of the sixth embodiment, and is a schematic configuration cross section. A difference from the above-described sixth embodiment is that a concave portion h is held on the surface of the stator d. The seal fin tip c is positioned so as to face the seal fin side surface h1 of the recess h of the stator d in a flow direction Y through a certain gap, and the seal fin tip c is a radial direction on the upstream side of the working fluid. It can be moved at a position tilted upward.

  FIG. 11 is a schematic view showing the seventh embodiment. The difference from the above-described embodiments is that the convex portion g ′ provided on the rotor f is on the seal fin side, that is, the surface g1 facing the tip portion c of the seal fin is separated from the seal fin in the radial direction upward (outward). It is a point inclined in the direction (the surface g1 of the convex part g ′ facing the tip part c of the seal fin is inclined to the upstream side of the working fluid).

  At this time, the bending amount with respect to the flow direction Y of the tip end portion c of the seal fin is smaller than the difference in the flow direction elongation amount of the working fluid of the rotor f with respect to the stator d to which the seal fin is fixed. The seal device can be used when there is a greater difference in the flow direction elongation of the working fluid than when the surface g1 is not inclined.

  FIG. 12 is a modification of the seventh embodiment, and is a schematic view seen from the rotation direction. The difference from the above-described embodiments is that the recess h ′ provided in the rotor f is on the seal fin side, that is, the surface h1 facing the tip end c of the seal fin is radially upward (outward) away from the seal fin. It is a point that is inclined to.

  FIG. 13 is a modified example of the seventh embodiment, and is a schematic view seen from the rotation direction. The difference from the above-described embodiments is that the surface g1 on the seal fin side of the convex portion g ′ provided on the stator d is inclined radially downward (inward) away from the seal fin. .

  FIG. 14 is a modification of the seventh embodiment, and is a schematic view seen from the rotation direction. The difference from the above-described embodiments is that the surface h1 on the seal fin side of the recess h ′ of the stator d is formed so as to be inclined downward in the radial direction in a direction away from the seal fin.

  FIG. 15 is an enlarged view of the tip of the seal fin showing the eighth embodiment. In addition, the same code | symbol is attached | subjected to the part which is the same as the component of 1st embodiment, or a corresponding part.

  The tip of the seal fin tip c is formed in an arc as viewed from the flow direction. Further, in order to couple the seal fin fixing part a and the seal fin tip part c, a joint part b as shown in the figure is provided. A hole b1 into which a pin is inserted is formed in the joint portion b, and the seal fin fixing portion a and the seal fin tip portion c are coupled by the pin, and the seal fin tip portion c can be rotated around the pin.

  FIG. 16 is a schematic diagram showing a modification of the eighth embodiment. In addition, the same code | symbol is attached | subjected to the part which is the same as the component of 8th embodiment, or a corresponding part.

  The seal fin can obtain a predetermined effect even with the configurations of (1), (2), and (3) in FIG. 16, but as shown in (4) and (5), the seal fin is fixed to the seal fin fixing portion a. If b2 is provided, it is possible to prevent the seal fin tip c from rotating downward from a predetermined radial position. The configurations of (4) and (5) are preferably used in the case where the effect is not obtained when the front end portion c of the seal fin rotates from the front side to the rear side in the flow direction. During normal operation, a pressure difference is generated between the seal fins from the upstream side to the downstream side in the flow direction, so that the seal tip c contacts the restraint b2.

  The movable joint portion of the seal fin is installed between the radially inner peripheral end and the outer peripheral end of the fixed portion. As the above-described restraining portion b2, a plate having a length corresponding to the tip end portion c is disposed at the joint portion b at the maximum so that the tip portion c of the seal fin does not rotate downstream of the working fluid from the initial position by the plate. It is a restraint.

  17 and 18 are modifications of the eighth embodiment, and are configuration diagrams viewed from the flow direction. In addition, the same code | symbol is attached | subjected to the part which is the same as the component of 8th embodiment, or a corresponding part.

  In FIG. 17, the fixing part a of the seal fin is formed in a concave shape, and the tip part c having a convex shape is assembled there in the radial direction to constitute the sealing device. For example, as shown in FIG. The same effect can be obtained even if the tip end portion c is concave. Further, when the material of the fixing part a and the tip part c of the seal fin is made of different materials, a material softer than that of the seal fin having no joint part b at the tip part c is adopted. It is possible to reduce the wear that occurs in the case.

  Also, by making the seal fin tip part a material different from that of the fixed part, it is not necessary to replace all the seal fins including the fixed part when it comes into contact with the rotor or stator against the seal fin and wears or breaks. By adopting a material having rigidity lower than that of the rotor or stator for the seal fin tip, it is possible to reduce wear or damage to the rotor or stator.

  According to the sealing device according to each of the embodiments described above, the seal fin provided in the sealing device is constituted by the tip portion c that can be rotated by the fixed portion a and the joint portion b, so that the rotor or the stator is opposed to the tip portion of the seal fin. Since the wear and breakage that occur when they come into contact with each other can be reduced or eliminated, the reliability and performance of the turbine member can be improved.

  That is, the gap between the rotating side and the stationary side is minimized during turbine operation, and the tip of the seal fin automatically moves when the rotating side and the stationary side come into contact with each other. It is possible to reduce the force applied to the seal device, and it is possible to provide a reliable and improved sealing device.

  Therefore, during unsteady operation such as starting and stopping of the turbine, even if the seal installed in the gap between the rotor and the stator comes into contact with the turbine member, the excessive force generated in the seal fin is reduced. Wear or damage to the turbine member can be reduced or eliminated, thereby improving the reliability of the turbine member. Further, since the gap in the radial direction or the flow direction of the seal insertion portion can be reduced, the turbine performance can be improved by increasing the number of seal fins accordingly, or the rotor rigidity can be increased by shortening the rotor shaft length. Therefore, the reliability of the rotor can be improved.

1 is a schematic cross-sectional view of a first embodiment of a sealing device according to the present invention. It is a modification of a first embodiment, and is a schematic structure sectional view seen from a rotation direction. It is a modification of a first embodiment, and is a schematic structure sectional view seen from a rotation direction. The schematic structure sectional drawing of 2nd embodiment of the sealing device based on this invention. The schematic structure sectional drawing of 3rd embodiment of the sealing device based on this invention. It is a modification of a third embodiment, and is a schematic structure sectional view seen from a rotation direction. Sectional drawing of schematic structure of 4th embodiment of the sealing device based on this invention. The schematic structure sectional view of a fifth embodiment of the sealing device according to the present invention. The schematic structure sectional view of a 6th embodiment of a seal device concerning the present invention. It is a modification of 6th embodiment, and is schematic structure sectional drawing seen from the rotation direction. Schematic of 7th embodiment of the sealing device based on this invention. It is the modification of 7th embodiment, and is the schematic seen from the rotation direction. It is the modification of 7th embodiment, and is the schematic seen from the rotation direction. It is the modification of 7th embodiment, and is the schematic seen from the rotation direction. The enlarged view of the seal fin front-end | tip of 8th embodiment of a sealing device. It is a modification of 8th embodiment and is schematic structure sectional drawing. It is a modification of 8th embodiment and is schematic structure sectional drawing. It is a modification of 8th embodiment and is schematic structure sectional drawing.

Explanation of symbols

a Seal fin fixing part b Seal fin joint part b1 Pin insertion hole b2 Restriction part c Seal fin tip part c1 Seal fin rotation restriction part d Stator e Packing ring f Rotor f1 Cover g, g 'Convex part h, h' Concave part g1, h1 surface R radial direction X rotational direction Y Turbine working fluid flow direction

Claims (9)

In a sealing device of a rotary fluid machine in which seal fins are disposed in a gap portion between a rotor and a stator,
The seal fin is attached to the rotor or the stator and has a joint portion at least at one position thereof, and the tip of the seal fin is rotated around the joint portion by contact between the seal fin and the rotor or the stator. A seal device for a rotary fluid machine, wherein the seal fin tip is movable to the upstream side of the working fluid from a position inclined to the upstream side of the working fluid. In a sealing device of a rotary fluid machine in which seal fins are disposed in a gap portion between a rotor and a stator,
Provided with a convex or concave portion on the outer periphery of the rotor,
The seal fin is attached to a portion of the stator facing the convex or concave portion, and has a joint portion at least at one position thereof, and the seal fin tip is centered on the joint portion by contact of the seal fin and the rotor. A seal device for a rotary fluid machine, wherein the seal fin tip is movable to the downstream side of the working fluid from a position where the portion is inclined to the upstream side of the working fluid of the rotary fluid machine. In a sealing device of a rotary fluid machine in which seal fins are disposed in a gap portion between a rotor and a stator,
Provided with a convex or concave portion on the inner periphery of the stator,
The seal fin is attached to a rotor at a portion facing the convex or concave portion, and has a joint portion at least at one position, and the seal fin tip is centered on the joint portion by contact of the seal fin and the stator. A seal device for a rotary fluid machine, wherein the seal fin tip is movable to the downstream side of the working fluid from a position where the portion is inclined to the upstream side of the working fluid of the rotary fluid machine. In claim 2 or 3,
The sealing fin of the rotary fluid machine, wherein the sealing fin has a tip end that is movable around the joint by contact with a side surface of the convex or concave portion. In claim 2 or 3,
A sealing device for a rotary fluid machine, wherein a side surface of a convex or concave portion facing the tip end portion of the seal fin is inclined toward the upstream side of the working fluid. In claim 1, 2, 3,
When the seal fin is joined to the fixed portion by a pin inserted in the circumferential direction, the seal fin tip formed in an arc when viewed from the flow direction, and when the seal fin tip contacts the structure during rotation, A sealing device for a rotary fluid machine, wherein a tip end portion of a seal fin rotates around a pin. In claim 1, 2, 3,
The seal fin of the rotary fluid machine, wherein the seal fin includes a restraining portion that restrains the tip end portion of the seal fin from rotating to the downstream side of the working fluid from the initial position. In claim 1, 2, 3,
The sealing device for a rotary fluid machine, wherein the seal fin is made of different materials for a tip portion and a fixed portion of the seal fin. In claim 8,
A sealing device for a rotary fluid machine, wherein the tip of the seal fin is made of a material having rigidity lower than that of a rotor or a stator.

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