JP5411569B2 - Seal structure and control method - Google Patents

Description

  The present invention relates to a seal structure provided in a steam turbine and a control method thereof.

In the case of a power plant that generates electricity by rotating a turbine (steam turbine) with steam generated by a steam generator such as a boiler, the steam turbine is provided with a high-pressure turbine, an intermediate-pressure turbine, and a low-pressure turbine from the upstream side of the steam flow. The steam rotating the low-pressure turbine is introduced into the condenser via the exhaust chamber, condensed in the condenser, and supplied to the steam generator as feed water.
In a steam turbine constituting such a power plant, a stationary blade fixed inside a casing is arranged between a moving blade and a moving blade that rotate integrally with a rotor, and a paragraph is formed by the moving blade and the stationary blade. The

  Then, the steam introduced into the casing flows inside the casing of the steam turbine, and expands while alternately passing between the stationary blade and the moving blade fixed to the rotor that is rotatably supported by the casing. Rotate the rotor. The moving blade provided on the most downstream side of the rotor, that is, the steam that has passed through the moving blade in the final stage is configured to be discharged out of the casing.

  In such a steam turbine, since the rotor rotates when the steam hits the moving blade, the steam from the clearance between the stationary part and the rotating part, such as a stationary blade and the rotor, is used in order to use the steam efficiently. It is required to improve the sealing performance between the fixed part and the rotating part so as to reduce the leakage of the air as much as possible.

  In order to cope with such problems, conventionally, a labyrinth seal device having fins (seal fins) is provided between a rotating part such as a rotor and a fixed part such as a stationary blade, and further, machinability is provided at a position facing the fins. A technique of a seal structure using a member (abradable material) excellent in the above is disclosed (for example, see Patent Document 1). According to the technique disclosed in Patent Document 1, even if the fin and the abradable material come into contact with each other, the abradable material is cut by the fin, so that damage to the fin can be prevented.

  However, if the fin and abradable material are arranged so that the clearance between the rotating part and the fixed part becomes as small as possible to improve the sealing performance, the contact between the fin and the abradable material increases and the rotating part rotates. Since the resistance (rotational resistance) to the rotor increases, for example, when the steam pressure is relatively low, such as at the initial startup of the steam turbine, the rotor is difficult to rotate, making it difficult to start the steam turbine smoothly. Occurs.

Furthermore, for example, frictional heat generated by the contact between the fins provided in the rotating part and the abradable material provided in the fixed part is transferred to the rotating part, causing the rotating part to become high temperature, which causes problems such as thermal expansion and thermal bending. Such thermal deformation occurs. And the problem that the turbine efficiency of a steam turbine falls arises.
Then, the technique of the seal structure which has a heat insulation layer which suppresses the heat transfer to a rotation part is disclosed (for example, refer patent document 2).
According to the technique disclosed in Patent Document 2, for example, by having a heat insulating layer between a fin provided in the rotating part and the rotating part, frictional heat generated by contact between the rotating part and the fixed part is transferred to the rotating part. That is restrained.

Japanese Patent Laid-Open No. 2002-228013 JP 2007-16704 A

  However, in the technique disclosed in Patent Document 2, when the rotating portion rotates continuously for a long time and the contact between the fin and the abradable material takes a long time, the generated frictional heat is stored in the heat insulating layer, and There is a problem that the heat stored in the heat insulating layer is transferred to the rotating part and the rotating part becomes high temperature.

Further, the rotational resistance increases due to the contact between the fins and the abradable material, and when the steam pressure is low, the rotor does not rotate smoothly, and the steam turbine cannot be smoothly started up.
In order to prevent contact between the fin and the abradable material, if the clearance between the fin and the abradable material is increased, the clearance between the rotating part and the fixed part will be increased, and steam leakage will increase. As a result, improvement in the turbine efficiency of the steam turbine cannot be expected.

  Therefore, the present invention can improve the sealing performance between the rotating part and the fixed part and can smoothly start up the steam turbine, and suppresses the temperature rise of the rotating part even if the rotating part rotates continuously for a long time. It is an object of the present invention to provide a seal structure and a control method thereof.

  In order to solve the above-described problems, the present invention provides a fin provided in the rotating portion and a spacer provided in the fixed portion facing each other, a fin provided in the fixed portion and a spacer provided in the rotating portion are opposed to each other, and further, the spacer is made air permeable. A seal structure that is made of metal and that can move in a direction in which the fins and spacers provided in the fixed part approach and separate from the rotating part, and a control method thereof.

  According to the present invention, the sealing performance between the rotating part and the fixed part can be improved and the steam turbine can be started up smoothly, and the temperature rise of the rotating part can be suppressed even if the rotating part rotates continuously for a long time. A seal structure and a control method thereof can be provided.

It is a schematic system diagram of a power plant provided with the steam turbine concerning this embodiment. FIG. 2 is a partially enlarged view of the steam turbine of FIG. 1. FIG. 3 is an enlarged view of a portion A1 in FIG. 2. FIG. 4 is an enlarged view of a portion A2 in FIG. 3. (A) is X1-X1 sectional drawing of FIG. 2, (b) is the A3 part enlarged view of (a) of FIG. It is the schematic which shows one structural example of a high / low type labyrinth sealing device, Comprising: It is a figure which shows the form with which a sealing board is equipped with a sealing fin. It is the schematic which shows one structural example of a high / low type labyrinth seal device, Comprising: It is a figure which shows the form with which a rotor is equipped with a seal fin. (A) is X2-X2 sectional drawing of FIG. 2, (b) is the A4 part enlarged view of (a) of FIG. It is the schematic which shows the front-end | tip of a moving blade. It is the schematic which shows one structural example of the labyrinth seal apparatus provided with the compression spring which connects a piston main body to the circumferential direction. It is the schematic which shows one structural example of the labyrinth seal apparatus which flows in a steam for a drive from a high pressure steam supply source to a pressurized chamber, and moves a piston head.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings as appropriate.
As shown in FIG. 1, the power plant 1 includes a boiler 10, a steam turbine 2 (a high pressure turbine 12, an intermediate pressure turbine 14, and a low pressure turbine 16), a generator 18, a condenser 20, and the like. The rotor 2a of the low-pressure turbine 16 is connected to the drive shaft 22 of the generator 18, and the generator 18 is driven by the rotation of the low-pressure turbine 16 to generate power.

  The boiler 10 is a steam generator, includes a reheater 24, and is connected to the inlet side of the high-pressure turbine 12 via a pipe 26. The outlet side of the high pressure turbine 12 is connected to the reheater 24 of the boiler 10 via a pipe 28. The reheater 24 is connected to the inlet side of the intermediate pressure turbine 14 via a pipe 30, and the outlet side of the intermediate pressure turbine 14 is connected to the inlet side of the low pressure turbine 16 via a pipe 32.

  The piping 26 and the piping 30 are provided with a control valve B, which functions as a control valve for controlling the amount of steam St flowing into the high-pressure turbine 12 and the intermediate-pressure turbine 14, respectively. These control valves B are controlled by the control device 54 to control the amount of steam St flowing into the high-pressure turbine 12 and the intermediate-pressure turbine 14.

  The steam St generated in the boiler 10 flows into the low-pressure turbine 16 via the high-pressure turbine 12 and the intermediate-pressure turbine 14 and rotates the rotor 2 a provided in the low-pressure turbine 16. The steam St exhausted from the low-pressure turbine 16 by rotating the rotor 2a is condensed in the condenser 20 through the exhaust chamber 3 to become water (feed water), and then sent to the feed water heater 21 to supply water. It is heated by the heater 21 and is reintroduced into the boiler 10 which is a steam generator via another feed water heater (not shown), a high-pressure feed water pump (not shown), and the like.

As shown in FIG. 2, in the steam turbine 2 (for example, the high pressure turbine 12 shown in FIG. 1), a plurality of moving blades 2b fixed in a direction along the outer periphery of the rotor 2a are arranged in a plurality of rows in the axial direction. ing.
Further, a casing 2d containing the rotor 2a and the plurality of moving blades 2b, and a plurality of stationary blades 2c fixed to the casing 2d via the nozzle diaphragm outer ring side 80 are provided. The plurality of moving blades 2b and the plurality of stationary blades 2c are alternately arranged in the axial direction of the rotor 2a to form a paragraph.
Hereinafter, a direction along the outer periphery of the rotor 2a is referred to as a circumferential direction. That is, the rotor 2a rotates in the circumferential direction.

When the steam St generated in the boiler 10 (see FIG. 1) flows into the casing 2d of the steam turbine 2, the steam St circulates alternately between the stationary blade 2c and the moving blade 2b while being depressurized and expanded, and the rotor 2a Rotate.
Then, the steam St that has passed through the rotor blade 2b provided on the most downstream side of the rotor 2a, that is, the rotor blade 2b in the final stage is configured to be exhausted to the outside of the casing 2d.

  In the steam turbine 2 configured in this manner, the rotor 2a is efficiently rotated by the steam St flowing through the inside of the casing 2d. Therefore, the rotor 2a and the moving blade 2b which are rotating parts, the casing 2d which is a fixed part, and It is required to improve the sealing performance between the stationary blades 2c and suppress the amount of steam St (leakage steam) leaking from the clearance between the rotating part and the fixed part.

For example, in order to reduce the rotational resistance to the rotation of the rotor 2a, a clearance may be provided between the nozzle diaphragm inner ring side 70 provided at the tip of the stationary blade 2c and the rotor 2a. This clearance flows into the stationary blade 2c. It causes the leakage steam of the steam St. And since steam St used as leaked steam does not contribute to rotation of rotor 2a, if the quantity of leaked steam increases, turbine efficiency of steam turbine 2 will fall. Therefore, in order to improve the turbine efficiency of the steam turbine 2, it is preferable to reduce the amount of leaked steam.
For this reason, a configuration in which a clearance between the rotor 2a and the stationary blade 2c is generally reduced by incorporating a sealing device such as the labyrinth sealing device 60 between the nozzle diaphragm inner ring side 70 and the rotor 2a. With this configuration, the sealing performance between the rotor 2a and the stationary blade 2c is improved, and the amount of leaked steam can be reduced.

As shown in FIGS. 3 and 4, a seal substrate 61 having a plurality of seal fins 62 is provided on the rotor 2 a side of the nozzle diaphragm inner ring side 70 according to the present embodiment.
A plurality of grooves 63 formed in the circumferential direction along the axial direction of the rotor 2 a are provided in the seal substrate 61 at predetermined intervals, and the seal fins 62 are caulked and fixed to the grooves 63, respectively.

  Further, a plurality of grooves 2a2 formed in the circumferential direction along the axial direction of the rotor 2a are also provided in the rotor 2a at predetermined intervals, and the seal fins 2a1 are caulked and fixed to the grooves 2a2, respectively.

.. And the seal fins 2a1, 2a1,... On the rotor 2a side are alternately arranged in the axial direction of the rotor 2a.
Thus, the labyrinth seal device 60 is configured including the seal substrate 61 provided with the plurality of seal fins 62.

  Conventionally, the seal fins 62, 62,... On the seal substrate 61 side and the rotor 2a and the seal fins 2a1, 2a1,. With this configuration, minute clearances are generated between the seal fins 62, 62,... And the rotor 2a, and between the seal fins 2a1, 2a1,. Is reduced.

However, the steam St passing through these clearances becomes leaked steam without contributing to the rotation of the rotor 2a. And a steam leakage loss generate | occur | produces with leaking steam, and the turbine efficiency of the steam turbine 2 (refer FIG. 1) falls.
Therefore, in the present embodiment, between the seal fins 62, 62,... On the seal substrate 61 side and the rotor 2a, and between the seal fins 2a1, 2a1,. Air permeable spacers 4, 4,... (Spacers) made of air permeable metal are attached.

Further, the seal substrate 61 provided with the seal fins 62, 62,... And the air permeable spacers 4, 4,... Moves in the direction approaching or moving away from the rotor 2a, that is, the rotational radius direction of the rotor 2a. It is possible.
Hereinafter, the breathable spacer 4 on the seal substrate 61 side is referred to as 4a, and the breathable spacer 4 on the rotor 2a side is referred to as 4b.
And by this structure, the seal fins 62, 62,... And the air permeable spacers 4a, 4a,... Provided in the stationary blade 2c (see FIG. 2) that is a fixed portion are provided to the rotor 2a that is a rotating portion. Can move in the direction of approaching or moving away.

As shown in FIG. 3, air permeable spacers 4 b, 4 b,... Are attached to the rotor 2 a at positions facing the seal fins 62, 62,.
In addition, air permeable spacers 4a, 4a,... Are attached to the seal substrate 61 at positions facing the seal fins 2a1, 2a1,.

This structure results in a seal structure in which breathable spacers 4, 4,... Made of a breathable metal are attached to both the rotor 2a (rotating portion) and the seal substrate 61 (fixed portion).
The method for attaching the air permeable spacer 4 to the rotor 2a and the seal substrate 61 is not limited and may be fixed by brazing, for example.

  Further, each of the plurality of air permeable spacers 4b on the rotor 2a side is attached to the outer periphery of the rotor 2a along the circumferential direction, and the seal fins 62, 62, ... on the seal substrate 61 side and the air permeability on the rotor 2a side. The spacers 4b, 4b,... Are configured to always face each other even when the rotor 2a rotates. Further, each of the plurality of seal fins 2a1 on the rotor 2a side is provided along the circumferential direction, and the seal fins 2a1, 2a1,... On the rotor 2a side and the air-permeable spacers 4a, 4a,. Are configured to always face each other even when the rotor 2a rotates.

The breathable metal forming the breathable spacer 4 according to the present embodiment is a metal material that has a structure in which porous metal space portions (pores) are connected, and allows gas (vapor St) to flow therethrough. The breathable metal is a material having excellent machinability (abradable material), for example, a state in which the tip of the seal fin 62 on the seal substrate 61 side and the breathable spacer 4b on the rotor 2a side are in contact ( When the rotor 2a rotates in the contact state), for example, as shown in FIG. 4, the breathable spacer 4 (4b) is scraped but the seal fins 62 are not damaged.
Therefore, it is possible to improve the sealing performance between the stationary blade 2c (see FIG. 2) and the rotor 2a by configuring the tip of the seal fin 62 to contact the air permeable spacer 4b on the rotor 2a side.
Similarly, the tip of the seal fin 2a1 on the rotor 2a side is configured to come into contact with the air-permeable spacer 4a (see FIG. 3) on the seal substrate 61 side to improve the sealing performance between the stationary blade 2c and the rotor 2a. be able to.

As shown in FIG. 3, the clearance between the seal fins 62, 62,... And the rotor 2a, and the clearance between the seal fins 2a1, 2a1,. In order to improve the sealing performance between the blade 2c (see FIG. 2) and the rotor 2a, the position of the rotor 2a facing the seal fins 62, 62,... And the seal fins 2a1, 2a1 of the seal substrate 61 The technique of providing a spacer made of a material having excellent cutting properties such as an abradable material at a position opposed to... Is a known technique as described above.
However, in this technique, for example, frictional heat due to friction between the spacers rotating integrally with the rotor 2a and the seal fins 62, 62,... Is transferred to the rotor 2a, and the rotor 2a becomes high temperature. Then, problems such as shaft vibration may occur due to thermal deformation of the rotor 2a such as thermal bending due to non-uniform temperature distribution, for example.

  Further, a heat insulating member (not shown) is formed between the seal fins 62, 62,... On the seal substrate 61 side and the rotor 2a, and between the seal fins 2a1, 2a1,. Although a technique including a heat insulating layer is also known, even with this technique, the rotor 2a continuously rotates for a long time and the spacers and seal fins 62, 62,. When in contact, for example, frictional heat between the seal fins 62, 62,... And the spacer is gradually stored, and the heat insulation layer becomes high temperature. Then, the heat of the heat insulating layer is transferred to the rotor 2a, the rotor 2a becomes high temperature, and thermal deformation such as thermal bending due to non-uniform temperature distribution occurs.

For example, as shown in FIG. 4, when the spacer attached to the rotor 2a is a breathable spacer 4 (4b) made of a breathable metal, a small amount of steam St flows inside the breathable spacer 4 (4b).
The breathable spacer 4 is uniformly maintained at the same temperature as the steam St by the steam St that ventilates the inside of the breathable spacer 4. That is, the breathable spacer 4 does not become higher than the steam St.

  The air flow rate of the air permeable spacer 4 may be an air flow rate that does not affect the sealing performance, and the air flow rate that allows the air permeable spacer 4 to be kept uniformly at the same temperature as the steam St. The air permeability of the air permeable metal forming the air permeable spacer 4 is very small, and is a characteristic value of the air permeable metal determined by the arrangement density and size of the pores. The breathable spacer 4 may be formed using a breathable metal that can secure a ventilation amount that can be expected to maintain a uniform temperature at the same temperature as the steam St.

  Thus, by keeping the temperature of the air permeable spacer 4 equal to that of the steam St, the rotor 2a rotates continuously for a long time. For example, the seal fins 62, 62,. Even when the breathable spacers 4b, 4b,... That are in contact with each other for a long time, the temperature of the breathable spacers 4b, 4b,. Therefore, an excellent effect is obtained that the temperature of the rotor 2a can be suppressed from becoming higher than the steam St. Since the rotor 2a is designed with heat resistance against the temperature of the steam St, if the temperature of the rotor 2a is kept at the temperature of the steam St, thermal deformation such as excessive thermal stress and thermal bending occurs. The operation of the steam turbine 2 (see FIG. 1) is not hindered.

Note that the labyrinth seal device 60 illustrated in FIG. 3 may be configured to include the air permeable spacers 4, 4,... Only on either the rotor 2a side or the seal substrate 61 side.
Further, as shown in FIG. 4, the amount of the steam St that flows through the air-permeable spacer 4 is very small compared to the amount leaking from the clearance between the seal fin 62 and the rotor 2a. The turbine efficiency of 1) is not affected.

Furthermore, the seal substrate 61 according to the present embodiment is provided so as to be movable in the direction of approaching / separating from the rotor 2a.
As shown in FIG. 5 (a), the tip of the inner peripheral side of the stationary blade 2c is provided with a nozzle diaphragm inner ring side 70 along the circumferential direction, and the tip of the nozzle diaphragm inner ring side 70 on the inner peripheral side is For example, six seal substrates 61 divided in six in the circumferential direction are provided so as to surround the rotor 2a.

As shown in FIG. 5B, seal fins 62, 62,... Standing along the circumferential direction of the rotor 2a are fixed to the side of the rotor 2a of one seal substrate 61 by caulking or the like. , And air permeable spacers 4b, 4b,... Made of air permeable metal are attached to the outer periphery of the rotor 2a at positions facing the seal fins 62, 62,.
Further, as shown in FIG. 3, one seal substrate 61 has a ventilation made of a breathable metal in a shape along the circumferential direction at a position facing the seal fins 2 a 1, 2 a 1,. , Spacers 4a, 4a,... Are attached.

  In the present embodiment, all the seal substrates 61 are provided on the nozzle diaphragm inner ring side 70 so as to be movable in the direction approaching and separating from the rotor 2a, that is, in the rotational radius direction of the rotor 2a.

For example, as shown in FIG. 3, a hollow pressurizing chamber 71 is formed on the inner side 70 of the nozzle diaphragm, and a piston that reciprocates in the pressurizing chamber 71 in a direction approaching or moving away from the rotor 2a. A head 64 is provided. The piston head 64 is elastically supported by, for example, a plurality of return springs 66 (biasing means) arranged in two rows side by side in the circumferential direction, and a plurality of return springs 66 are attached to the piston head 64 in a direction away from the rotor 2a. It is energized by power.
Note that the number of the plurality of return springs 66 may be determined as appropriate.

  The pressurizing chamber 71 is configured to communicate with the outside of the nozzle diaphragm inner ring side 70 through the steam passage 72, so that the steam St flowing outside the nozzle diaphragm inner ring side 70 flows into the pressurizing chamber 71. When the pressure of the steam St acts on the piston head 64, the piston head 64 is configured to move in a direction close to the rotor 2a.

The piston head 64 is provided with a piston body 65. The piston main body 65 extends from the pressurizing chamber 71 to the rotor 2a side, and a tip portion projects outside the nozzle diaphragm inner ring side 70, and a seal substrate 61 is attached to the tip portion.
What is necessary is just to form the piston main body 65 integrally with the piston head 64, for example. The method for attaching the seal substrate 61 to the piston body 65 is not limited. For example, the seal substrate 61 may be fixed to the piston body 65 with a screw (not shown).
The movable portion is configured including the piston head 64, the piston main body 65, and the seal substrate 61.

When the piston head 64 is supported at a position away from the rotor 2a by the urging forces of the plurality of return springs 66, the seal substrate 61 is in a state of moving to a position away from the rotor 2a and the seals facing each other. The seal fins 62, 62, ... on the substrate 61 side and the air-permeable spacers 4b, 4b, ... on the rotor 2a side are not in contact (non-contact state), and the seal fins 62, 62, ... Are formed between the air-permeable spacers 4b, 4b,.
Similarly, the seal fins 2a1, 2a1,... On the rotor 2a side facing each other and the air-permeable spacers 4a, 4a,. .. and a clearance is formed between the breathable spacers 4a, 4a,.

The labyrinth seal device 60 in the present embodiment includes a pressurizing chamber 71, a steam passage 72, a piston head 64, a piston body 65, and a plurality of return springs 66 in addition to the seal substrate 61.
And the seal structure including the labyrinth seal device 60, the seal fins 2a1, 2a1,... And the breathable spacers 4b, 4b,... On the rotor 2a side is incorporated in the steam turbine 2 (see FIG. 1). become.

When the steam St generated in the boiler 10 (see FIG. 1) flows into the steam turbine 2, when the steam St passes between the stationary blade 2c and the moving blade 2b, a part of the steam St flows through the steam passage 72. It flows into the pressurizing chamber 71.
If the force (pressing force) that causes the pressure of the steam St flowing into the pressurizing chamber 71 to move the piston head 64 in the direction approaching the rotor 2a is smaller than the urging force of the plurality of return springs 66, the plurality of return springs 66 are The piston head 64 is supported at a position away from the rotor 2a.

  For example, when the load connected to the steam turbine 2 (see FIG. 1) increases and the pressure of the steam St flowing through the steam turbine 2 increases, the pressure of the steam St flowing into the pressurized chamber 71 also increases. When the pressure of the steam St that moves the piston head 64 in the direction of approaching the rotor 2a exceeds the biasing force of the plurality of return springs 66, the piston head 64 approaches the rotor 2a with the pressure of the steam St. The seal substrate 61 connected via the piston head 64 and the piston main body 65 moves in the direction approaching the rotor 2a.

  When the piston head 64 moves to the stop position on the side close to the rotor 2a in the pressurizing chamber 71, the seal fins 62, 62,... On the seal substrate 61 side and the air-permeable spacer 4b on the rotor 2a side. , 4b,... Are in contact with each other, when the pressure of the steam St flowing into the pressurizing chamber 71 increases, the seal fins 62, 62,. Can be brought into contact with each other. And the clearance between the seal fins 62, 62, ... and the air permeable spacers 4b, 4b, ... is eliminated, and the sealing performance between the stationary blade 2c (see Fig. 2) and the rotor 2a is improved.

  Similarly, when the piston head 64 moves in the pressurizing chamber 71 to the stop position on the side close to the rotor 2a, the air-permeable spacers 4a, 4a,. If the pressure of the steam St flowing into the pressurizing chamber 71 is increased, the sealable fins 2a1, 2a1,. The fins 2a1, 2a1,... Can be brought into contact with each other, and the sealing performance between the stationary blade 2c (see FIG. 2) and the rotor 2a is improved.

  As described above, the seal fins 62, 62,... On the seal substrate 61 side and the air permeable spacers 4b, 4b,... On the rotor 2a side are in contact with each other, and the seal fins 2a1, 2a1 on the rotor 2a side. When the breathable spacers 4a, 4a,... On the seal substrate 61 side are in contact with each other, the rotational resistance against rotation of the rotor 2a increases. Rotation resistance increased by contact between the fins 62, 62, ... and the air permeable spacers 4b, 4b, ... and contact between the seal fins 2a1, 2a1, ..., and the air permeable spacers 4a, 4a, ... The rotor 2a can be rotated against this. That is, the rotor 2a is rotated without being affected by the rotational resistance that increases due to the contact between the seal fins 62, 62,... And the seal fins 2a1, 2a1,. Can be made.

  In other words, the contact between the seal fins 62, 62,... And the air permeable spacers 4b, 4b,... And the contact between the seal fins 2a1, 2a1,. The biasing force of the plurality of return springs 66 may be set so that the piston head 64 moves in the direction approaching the rotor 2a with the pressure of the steam St that can rotate the rotor 2a without being affected by the increasing rotational resistance. .

  Note that the steam St flowing in the steam turbine 2 (see FIG. 1) expands from the upstream toward the downstream and depressurizes, so the downstream of the steam St flow is provided in the labyrinth seal device 60 of the stationary blade 2c. The structure which weakens the urging | biasing force of the some return spring 66 may be sufficient.

  Further, the number of the seal substrates 61 is not limited to six, and may be a labyrinth seal device 60 that includes seven or more seal substrates 61 along the circumferential direction, or five or less seal substrates 61. The labyrinth seal device 60 provided along the circumferential direction may be used.

In the steam turbine 2 (see FIG. 1) in which the seal structure configured in this way is incorporated, the seal fins 62, 62,. And the air-permeable spacers 4b, 4b, ... on the rotor 2a side are in a non-contact state, and the seal fins 2a1, 2a1, ... on the rotor 2a side and the air-permeable spacers 4a, 4a, ... on the seal substrate 61 side. ... is in a non-contact state.
Therefore, the rotational resistance to the rotation of the rotor 2a is reduced, and the rotor 2a rotates efficiently with the low-pressure steam St.

When the load of the steam turbine 2 (see FIG. 1) increases and the pressure of the steam St increases, the seal fins 62, 62,... And the breathable spacers 4b, 4b,. The fins 2a1, 2a1, ... and the breathable spacers 4a, 4a, ... are brought into contact with each other, and the sealing performance between the stationary blade 2c (see Fig. 2) and the rotor 2a is improved. Therefore, the turbine efficiency of the steam turbine 2 is improved.
Further, the steam St having a high pressure is in contact with the seal fins 62, 62,... And the breathable spacers 4b, 4b,... And the seal fins 2a1, 2a1,. The rotor 2a can be efficiently rotated without being affected by the rotational resistance that increases due to the contact.

  That is, in the steam turbine 2 (see FIG. 1), when the pressure of the steam St is relatively low, such as at the initial stage of startup, the seal fins 62, 62,. Are in a non-contact state, and the seal fins 2a1, 2a1,... On the rotor 2a side and the air-permeable spacers 4a, 4a,. Thus, the rotational resistance against the rotation of the rotor 2a is reduced. Accordingly, the steam turbine 2 can be started up smoothly by efficiently rotating the rotor 2a with the low-pressure steam St.

  Further, when the load increases and the steam pressure of the steam St increases, the steam turbine 2 (see FIG. 1) has the seal fins 62, 62,... On the seal substrate 61 side and the air permeability on the rotor 2a side. The spacers 4b, 4b, ... are in contact with each other, and the seal fins 2a1, 2a1, ... on the rotor 2a side and the air-permeable spacers 4a, 4a, ... on the seal substrate 61 side are in contact. The amount of leakage steam between the stationary blade 2c (see FIG. 2) and the rotor 2a is reduced, and the turbine efficiency is improved.

  As described above, the configuration example in which the plurality of air permeable spacers 4 are attached to the rotor 2a and the labyrinth seal device 60, and the seal substrate 61 constituting the labyrinth seal device 60 are movable in a direction approaching and separating from the rotor 2a. Although one configuration example provided in the nozzle diaphragm inner ring side 70 has been described, the configuration of the present invention is not limited to this.

  For example, the labyrinth seal device 60 includes a high-low labyrinth seal device in addition to the shape shown in FIG. The present invention can also be applied to a high-low labyrinth seal device.

  As shown in FIG. 6, in the high / low labyrinth seal device 60a, a seal substrate 61 having seal fins 62, 62,... Standing on the nozzle diaphragm inner ring side 70 along the circumferential direction is provided on the rotor 2a. On the outer periphery of the rotor 2a, convex portions 2a3, 2a3,... Are formed along the circumferential direction. The seal fins 62, 62,... On the seal substrate 61 side are arranged to face the convex portions 2a3, 2a3,... Of the rotor 2a and the concave portions 2a4, 2a4,. ing.

  Furthermore, the labyrinth seal device 60a includes a pressurizing chamber 71, a steam passage 72, a piston head 64, a piston main body 65, and a plurality of return springs 66 arranged in two rows in the circumferential direction.

6, the convex portions 2a3, 2a3,... And the concave portions 2a4, 2a4,... Formed on the rotor 2a have seal fins 62, 62,. The air-permeable spacers 4b, 4b,.
Thus, by attaching the air permeable spacers 4b, 4b,..., The sealing performance between the stationary blade 2c (see FIG. 2) and the rotor 2a can be improved.

In the steam turbine 2 (see FIG. 1), a labyrinth seal device 60a and a seal structure including the air permeable spacers 4b, 4b,.
In the high-low type labyrinth seal device 60a shown in FIG. 6, the air-permeable spacers 4b, 4b,... Are provided in any one of the convex portions 2a3, 2a3,. It is good also as a structure provided with ....

Also in the high / low labyrinth seal device 60a, the seal substrate 61 can be provided on the inner side 70 of the nozzle diaphragm so as to be movable in a direction approaching / separating from the rotor 2a.
With this configuration, the seal fins 62, 62,... Provided in the stationary blade 2c (see FIG. 2) that is a fixed portion can be moved in a direction that approaches and separates from the rotor 2a that is a rotating portion.

  The steam St flows through the steam passage 72 and flows into the pressurized chamber 71 as in the configuration shown in FIG. If the pressure of the steam St is high and the pressing force for moving the piston head 64 in the direction approaching the rotor 2a is equal to or greater than the urging force of the plurality of return springs 66, the piston head 64 moves in the direction approaching the rotor 2a. The seal substrate 61 that operates integrally with the piston head 64 moves through the piston body 65 in the direction approaching the rotor 2a.

  When the piston head 64 moves to the stop position on the side close to the rotor 2a in the pressurizing chamber 71, the seal fins 62, 62,... On the seal substrate 61 side and the convex portions 2a3, 2a3 of the rotor 2a. , ... and the breathable spacers 4b, 4b, ... attached to the recesses 2a4, 2a4, ... are in contact with each other, the pressure of the steam St flowing into the pressurizing chamber 71 is high. , And the air-permeable spacer 4b attached to the convex portions 2a3, 2a3,... And the concave portions 2a4, 2a4,. Are brought into contact with each other, and there is no clearance between the seal fins 62, 62,... And the air permeable spacers 4b, 4b,. Of the rotor 2a To improve sealing performance of.

Further, as shown in FIG. 7, a high / low labyrinth seal device 60b having a plurality of seal fins 2a5 on the outer periphery of the rotor 2a may be used.
In this case, the seal substrate 61a, side by side in the axial direction of the rotor 2a, the circumferential direction a plurality of convex portions 61a ₁ and a plurality of recesses 61a ₂ of a shape along the is formed, a plurality of convex portions 61a ₁ and a plurality of each recess 61a _2, breathable spacers 4a shaped along the circumferential direction is attached.

  The labyrinth seal device 60b is arranged in two rows side by side in the circumferential direction, for example, the seal substrate 61a to which the air-permeable spacer 4a is attached, the pressurizing chamber 71, the steam passage 72, the piston head 64, the piston main body 65. A plurality of return springs 66 are included.

Further, on the outer periphery of the rotor 2a, a seal is provided in the circumferential direction at a position facing the convex portions 61a ₁ , 61a ₁ ,... And the concave portions 61a ₂ , 61a ₂ ,. Fins 2a5, 2a5,... Are provided.

  The steam turbine 2 (see FIG. 1) incorporates a seal structure including the labyrinth seal device 60b and the seal fins 2a5 on the rotor 2a side.

Also in the labyrinth seal device 60b configured in this way, the seal substrate 61a can be provided on the nozzle diaphragm inner ring side 70 so as to be movable in a direction approaching or separating from the rotor 2a.
With this configuration, the air-permeable spacers 4a, 4a,... Provided in the stationary blade 2c (see FIG. 2) that is a fixed portion can be moved in a direction that approaches or separates from the rotor 2a that is a rotating portion.
Similarly to the labyrinth seal device 60 shown in FIG. 3, the steam St flows through the steam passage 72 and flows into the pressurized chamber 71. When the pressure of the steam St is high and the pressing force for moving the piston head 64 in the direction approaching the rotor 2a is equal to or greater than the urging force of the plurality of return springs 66, the piston head 64 moves in the direction approaching the rotor 2a, The seal substrate 61a, which operates integrally with the piston head 64, moves through the piston body 65 in a direction close to the rotor 2a.

  When the piston head 64 moves to the stop position on the side close to the rotor 2a in the pressurizing chamber 71, the air-permeable spacers 4a, 4a,... On the seal substrate 61a side and the seal fins 2a5 on the rotor 2a side. , 2a5,... Are in contact with each other, when the pressure of the steam St flowing into the pressurizing chamber 71 increases, the air-permeable spacers 4a, 4a,. The seal fins 2a5, 2a5,... On the rotor 2a side are brought into contact with each other, and the clearance between the air-permeable spacers 4a, 4a,. The sealing performance between the rotor (see FIG. 2) and the rotor 2a is improved.

  In this way, the labyrinth seal device 60b can be configured by providing the nozzle diaphragm inner ring side 70 with the high-low type seal substrate 61a so as to be movable toward and away from the rotor 2a. The same effect as the sealing device 60 is obtained.

The present embodiment can also be applied to a labyrinth seal device provided between the nozzle diaphragm outer ring side 80 (see FIG. 2) and the moving blade 2b (see FIG. 2).
As shown in FIG. 8 (a), the tip of the moving blade 2b is provided with a cover 2g for reducing the clearance between the nozzle diaphragm outer ring side 80 and the moving blade 2b, as shown in FIG. 8 (b). As described above, the cover 2g is provided with a plurality of seal fins 2g1.

As shown in FIG. 8A, the cover 2g is provided in an annular shape along the circumferential direction at the tip of the moving blade 2b, and the seal fins 2g1, 2g1,... (See FIG. 8B) are provided. The cover 2g is erected along the circumferential direction.
A seal substrate 91 is provided on the nozzle diaphragm outer ring side 80 so as to face the cover 2g provided on the rotor blade 2b.

  The moving blade 2b side of the nozzle diaphragm outer ring side 80 is formed along the circumferential direction. Between the nozzle diaphragm outer ring side 80 and the moving blade 2b, for example, six seal substrates 91 divided into six equal parts in the circumferential direction are provided. , So as to surround the rotor blade 2b.

  As shown in FIG. 8 (b), breathable spacers 4a, 4a,... Are attached along the circumferential direction on the moving blade 2b side of one seal substrate 91, and the cover 2g is breathable. Seal fins 2g1, 2g1,... Are provided at positions facing the spacers 4a, 4a,.

  In the present embodiment, all the seal substrates 91 are provided on the nozzle diaphragm outer ring side 80 so as to be movable in the direction approaching and separating from the moving blade 2b, that is, in the rotational radius direction of the moving blade 2b.

As shown in FIG. 9, the seal substrate 91 is, for example, a high-low type, and the seal substrate 91 includes a plurality of convex portions 91 a and a plurality of concave portions having a shape along the rotation direction of the rotor blade 2 b, that is, the circumferential direction. 91b is formed side by side in the axial direction of the rotor 2a (see FIG. 2). And the air permeable spacer 4a is attached to each of the some convex part 91a and the some recessed part 91b in the shape along the circumferential direction.
With this configuration, the air-permeable spacers 4a, 4a,... Provided in the casing 2d (see FIG. 2) that is a fixed part can move in a direction that approaches and separates from the moving blade 2b that is a rotating part.

  Further, the cover 2g of the moving blade 2b has seal fins 2g1, 2g1,... At positions facing the convex portions 91a, 91a,. It is erected along the circumferential direction.

A hollow pressurizing chamber 81 is formed on the nozzle diaphragm outer ring side 80, and a piston head 92 that reciprocates in the direction approaching and separating from the moving blade 2 b is provided inside the pressurizing chamber 81. For example, the piston head 92 is elastically supported by a plurality of return springs 94 (biasing means) arranged in two rows in the circumferential direction, and is urged by the plurality of return springs 94 in a direction away from the moving blade 2b. Has been.
In addition, what is necessary is just to set the number of the some return springs 94 suitably.

  The pressurizing chamber 81 is configured to communicate with the outside of the nozzle diaphragm outer ring side 80 through the steam passage 82 so that the steam St flowing outside the nozzle diaphragm outer ring side 80 flows into the pressurizing chamber 81. And when the pressure of the vapor | steam St acts on the piston head 92, it is comprised so that the piston head 92 may move to the direction which adjoins the moving blade 2b.

The piston head 92 is provided with a piston body 93. The piston main body 93 extends from the pressurizing chamber 81 toward the moving blade 2b, and a tip portion projects outside the nozzle diaphragm outer ring side 80, and a seal substrate 91 is attached to the tip portion.
The piston body 93 may be formed integrally with the piston head 92, for example. The method for attaching the seal substrate 91 to the piston body 93 is not limited. For example, the seal substrate 91 may be fixed to the piston body 93 with a screw (not shown).
And a movable part is comprised including the piston head 92, the piston main body 93, and the seal | sticker board | substrate 91. FIG.
The labyrinth seal device 90 includes a seal substrate 91, a piston head 92, a piston body 93, a plurality of return springs 94, a pressurizing chamber 81, and a steam passage 82.

  In the steam turbine 2 (see FIG. 1), a labyrinth seal device 90 and a seal structure including the seal fins 2g1, 2g1,.

  When the piston head 92 of the labyrinth seal device 90 is supported at a position separated from the moving blade 2b by the biasing force of a plurality of return springs 94, the seal substrate 91 is in a state of moving to a position separated from the moving blade 2b. The air-permeable spacers 4a, 4a,... On the seal substrate 91 side facing each other and the seal fins 2g1, 2g1,. A clearance is formed between 4a,... And seal fins 2g1, 2g1,.

When the steam St generated in the boiler 10 (see FIG. 1) flows into the steam turbine 2 (see FIG. 1), when the steam St passes outside the nozzle diaphragm outer ring side 80, a part of the steam St passes through the steam passage 82. It flows and flows into the pressurizing chamber 81.
If the pressure of the steam St flowing into the pressurizing chamber 81 is smaller than the urging force of the plurality of return springs 94, the plurality of return springs 94 are The head 92 is supported at a position away from the moving blade 2b.
When the piston head 92 is supported at a position separated from the moving blade 2b by the urging forces of the plurality of return springs 94, the seal substrate 91 is in a state of moving to a position separated from the moving blade 2b and faces each other. The air-permeable spacers 4a, 4a,... On the seal substrate 91 side to be in contact with the seal fins 2g1, 2g1,. A clearance is formed between 4a, 4a,... And seal fins 2g1, 2g1,.

  When the pressure of the steam St flowing into the steam turbine 2 (see FIG. 1) increases, the pressure of the steam St flowing into the pressurizing chamber 81 also increases. When the pressure of the steam St that moves the piston head 92 in the direction of approaching the moving blade 2b becomes equal to or greater than the urging force of the plurality of return springs 94, the piston head 92 is separated from the moving blade 2b by the pressure of the steam St. The seal substrate 91 that moves in the approaching direction and is connected via the piston head 92 and the piston body 93 moves in the direction of approaching the moving blade 2b.

  When the piston head 92 moves in the pressurizing chamber 81 to the stop position on the side close to the moving blade 2b, the air-permeable spacers 4a, 4a,. If the seal fins 2g1, 2g1,... On the side are in contact with each other, the breathable spacers 4a, 4a on the seal substrate 91 side when the pressure of the steam St flowing into the pressurizing chamber 81 increases. ,... Can be brought into contact with the seal fins 2g1, 2g1,. As a result, there is no clearance between the seal fins 2g1, 2g1,... And the air permeable spacers 4a, 4a,..., And the sealing performance between the nozzle diaphragm outer ring side 80 and the moving blade 2b is improved.

As in the labyrinth seal device 60 shown in FIG. 3, the rotor 2a is not affected by the rotational resistance that increases due to the contact between the seal fins 2g1, 2g1,... And the breathable spacers 4a, 4a,. The biasing force of the plurality of return springs 94 may be set so that the piston head 92 moves in the direction approaching the moving blade 2b with the pressure of the steam St that can rotate.
Further, since the steam St flowing in the steam turbine 2 (see FIG. 1) expands from the upstream toward the downstream and depressurizes, the downstream of the flow of the steam St as in the labyrinth seal device 60 shown in FIG. As such, the urging force of the plurality of return springs 94 may be weakened.

  Further, the number of seal substrates 91 is not limited to six, and may be a labyrinth seal device 90 including seven or more seal substrates 91 along the circumferential direction, or five or less seal substrates 91. It may be a labyrinth seal device 90 provided along the circumferential direction.

  The steam turbine 2 (see FIG. 1) including the labyrinth seal device 90 shown in FIG. 9 and the seal fins 2g1, 2g1,... When the temperature is low, the air-permeable spacers 4a, 4a,... On the seal substrate 91 side and the seal fins 2g1, 2g1,. , 4a,... And seal fins 2g1, 2g1,..., And a rotational resistance against rotation of the rotor blade 2b (rotating part) is reduced. The rotor 2a rotates efficiently with the low-pressure steam St, and the steam turbine 2 rises smoothly.

  Then, when the load of the steam turbine 2 (see FIG. 1) increases and the steam pressure of the steam St increases, the steam turbine 2 includes the air-permeable spacers 4a, 4a,. The seal fins 2g1, 2g1,... On the cover 2g side of 2b are brought into contact with each other, and there is no clearance between the breathable spacers 4a, 4a,. The sealing performance between the outer ring side 80 and the moving blade 2b is improved. In the steam turbine 2, the amount of leaked steam generated between the nozzle diaphragm outer ring side 80 and the rotor blade 2b is reduced, and the turbine efficiency is improved.

  The labyrinth seal device 90 shown in FIG. 9 has a structure in which a plurality of breathable spacers 4a are attached to a seal substrate 91 and a plurality of seal fins 2g1 are provided on the cover 2g. A structure may be provided in which fins are provided and a plurality of air-permeable spacers are attached to the cover 2g.

  Alternatively, the seal substrate 91 and the cover 2g may be provided with a plurality of seal fins. In this case, a configuration in which a plurality of air permeable spacers are attached to a position of the cover 2g facing the plurality of seal fins on the seal substrate 91 side and a position of the seal substrate 91 facing the plurality of seal fins on the cover 2g side. do it.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and appropriate design changes can be made without departing from the spirit of the invention.

  For example, in the labyrinth seal device 60 shown in FIG. 3, the seal substrate 61 is urged in a direction away from the rotor 2 a by a plurality of return springs 66 that elastically support the piston head 64 in the pressurizing chamber 71. As shown in FIG. 10, the piston main body 65 of the adjacent seal substrate 61 may be connected in the circumferential direction by a compression spring 66a (biasing means).

The compression spring 66a is provided in a compressed state between adjacent piston main bodies 65, and biases the piston main bodies 65 in directions in which the adjacent piston main bodies 65 are separated from each other.
One piston body 65 is elastically supported by the compression spring 66a in a state where it is moved away from the rotor 2a, and the seal substrate 61 is attached to the piston body 65. It is supported at a position away from.

When the steam St (see FIG. 3) flows into the pressurizing chamber 71, the pressing force that moves the pressure of the steam St in the direction in which the piston head 64 approaches the rotor 2a exceeds the urging force of the compression spring 66a. The piston head 64 moves in the direction approaching the rotor 2a. As the piston head 64 moves, the seal substrate 61 moves in the direction approaching the rotor 2a.
Therefore, the same effect as the labyrinth seal device 60 shown in FIG. 3 is obtained.

  Further, in the labyrinth seal device 60 shown in FIG. 3, the piston head 64 is driven by the pressure of the steam St flowing through the steam turbine 2 (see FIG. 1). For example, as shown in FIG. Even if the piston head 64 is moved in the direction close to the rotor 2a by the pressure of high-pressure steam (driving steam) for driving the piston head 64 flowing into the pressurized chamber 71 from the steam supply source 102. Good.

  A labyrinth seal device 60c shown in FIG. 11 includes a valve control device 100, an operating state detection device 101, a high-pressure steam supply source 102, and an electromagnetic valve 103 in addition to the configuration of the labyrinth seal device 60 shown in FIG. .

  The steam turbine 2 (see FIG. 1) incorporates a labyrinth seal device 60c, a seal structure including a plurality of seal fins 2a1 and a plurality of air permeable spacers 4b on the rotor 2a side.

A high pressure steam supply source 102 is connected to the pressurizing chamber 71 via an electromagnetic valve 103. Furthermore, the valve control apparatus 100 which controls opening and closing of the solenoid valve 103 is provided.
Further, the valve control device 100 is preferably configured to control the opening and closing of the electromagnetic valve 103 based on the operation state of the steam turbine 2 (see FIG. 1), and the operation state detection device 101 that detects the operation state of the steam turbine 2. Is equipped.
According to this configuration, the valve control device 100 moves the movable part including the piston head 64, the piston main body 65, and the seal substrate 61 in a direction close to the rotor 2a based on the operation state of the steam turbine 2. be able to.
A driving device is configured including the pressurizing chamber 71, the valve control device 100, the high-pressure steam supply source 102, and the electromagnetic valve 103.

The operation state of the steam turbine 2 (see FIG. 2) is preferably detected by, for example, the rotation speed of the rotor 2a, and the operation state detection device 101 is a rotation speed detection device that detects the rotation speed of the rotor 2a. .
The operating state detection device 101 which is a rotation speed detection device detects the rotation speed of the rotor 2a, converts it into a detection signal, and inputs it to the valve control device 100.
The valve control device 100 calculates the rotational speed of the rotor 2a based on the detection signal input from the operating state detection device 101 (rotational speed detection device).

When the calculated rotation speed of the rotor 2a is smaller than a predetermined rotation speed set in advance, the valve control device 100 transmits a control signal for closing the electromagnetic valve 103 to the electromagnetic valve 103.
The predetermined rotational speed at this time may be set as appropriate based on the performance of the steam turbine 2 (see FIG. 1).
The electromagnetic valve 103 is closed based on a control signal transmitted from the valve control device 100 to block the flow of driving steam from the high-pressure steam supply source 102 into the pressurizing chamber 71.

When the driving steam does not flow into the pressurizing chamber 71, the piston head 64 moves in a direction away from the rotor 2a by the urging forces of the plurality of return springs 66.
When the piston head 64 moves away from the rotor 2a, the seal substrate 61 moves away from the rotor 2a, and the seal fins 62, 62,... On the seal substrate 61 side and the air permeable spacer on the rotor 2a side. 4b, 4b, ... are in a non-contact state, and the air-permeable spacers 4a, 4a, ... on the seal substrate 61 side and the seal fins 2a1, 2a1, ... on the rotor 2a side are in a non-contact state. . And the rotational resistance with respect to rotation of the rotor 2a reduces.

In addition, when the calculated rotation speed of the rotor 2 a is equal to or higher than a predetermined rotation speed set in advance, the valve control device 100 transmits a control signal for opening the electromagnetic valve 103 to the electromagnetic valve 103.
The electromagnetic valve 103 is opened based on a control signal transmitted from the valve control device 100, and driving steam flows from the high-pressure steam supply source 102 into the pressurizing chamber 71.

The piston head 64 moves in the direction close to the rotor 2 a by the pressure of the driving steam flowing from the high-pressure steam supply source 102 into the pressurizing chamber 71.
When the piston head 64 moves in the direction approaching the rotor 2a, the seal substrate 61 moves in the direction approaching the rotor 2a, and the seal fins 62, 62,... On the seal substrate 61 side and the air permeable spacer on the rotor 2a side. 4b, 4b,... Are in contact with each other, and the seal fins 2a1, 2a1,... On the rotor 2a side and the air-permeable spacers 4a, 4a,.
And the sealing performance between the stationary blade 2c (refer FIG. 2) and the rotor 2a improves.

  For example, when the rotational speed of the rotor 2a is low, such as in the initial start-up of the steam turbine 2 (see FIG. 1), the valve control device 100 closes the electromagnetic valve 103 and seal fins 62, 62,. .. And the air-permeable spacers 4b, 4b,... On the rotor 2a side in a non-contact state, and the air-permeable spacers 4a, 4a,. Are made in a non-contact state to reduce rotational resistance against rotation of the rotor 2a. The rotor 2a is efficiently rotated by the steam St, and the steam turbine 2 starts up smoothly.

When the steam turbine 2 (see FIG. 1) is started up and the rotational speed of the rotor 2a is increased, the valve control device 100 opens the electromagnetic valve 103 and the seal fins 62, 62,. .. and the air-permeable spacers 4b, 4b,... On the rotor 2a side are brought into contact with each other, and the seal fins 2a1, 2a1,. ... is brought into contact.
In the steam turbine 2, the sealing performance between the stationary blade 2c (see FIG. 2) and the rotor 2a is improved, and the turbine efficiency is improved.

  The pressure of the driving steam is preferably a pressure that can move the piston head 64 in the direction of approaching the rotor 2 a against the urging force of the plurality of return springs 66.

Moreover, the structure which detects the driving | running state of the steam turbine 2 by the pressure of the steam St may be sufficient, for example. In this case, the operation state detection device 101 is a pressure detection device that detects the pressure of the steam St.
The operating state detection device 101 which is a pressure detection device detects the pressure of the steam St flowing through the steam turbine 2 (see FIG. 1) and inputs a detection signal to the valve control device 100. The valve control device 100 detects the steam St of the steam St. Calculate the pressure.

And the valve control apparatus 100 transmits the control signal which closes the solenoid valve 103 to the solenoid valve 103, when the pressure of the vapor | steam St is lower than the predetermined pressure value set beforehand.
The electromagnetic valve 103 is closed based on a control signal transmitted from the valve control device 100 to block the flow of driving steam from the high-pressure steam supply source 102 into the pressurizing chamber 71.
The predetermined pressure value at this time may be set as appropriate based on the performance of the steam turbine 2 (see FIG. 1).

When the driving steam does not flow into the pressurizing chamber 71, the piston head 64 moves in a direction away from the rotor 2a by the urging forces of the plurality of return springs 66.
When the piston head 64 moves away from the rotor 2a, the seal substrate 61 moves away from the rotor 2a, and the seal fins 62, 62,... On the seal substrate 61 side and the air permeable spacer on the rotor 2a side. 4b, 4b, ... are in a non-contact state, and the air-permeable spacers 4a, 4a, ... on the seal substrate 61 side and the seal fins 2a1, 2a1, ... on the rotor 2a side are in a non-contact state. . And the rotational resistance with respect to rotation of the rotor 2a reduces.

Further, the valve control device 100 transmits a control signal for opening the electromagnetic valve 103 to the electromagnetic valve 103 when the pressure of the steam St is equal to or higher than a predetermined pressure value set in advance.
The electromagnetic valve 103 is opened based on a control signal transmitted from the valve control device 100, and driving steam flows from the high-pressure steam supply source 102 into the pressurizing chamber 71.

The piston head 64 moves in the direction close to the rotor 2 a by the pressure of the driving steam flowing from the high-pressure steam supply source 102 into the pressurizing chamber 71.
When the piston head 64 moves in the direction approaching the rotor 2a, the seal substrate 61 moves in the direction approaching the rotor 2a, and the seal fins 62, 62,... On the seal substrate 61 side and the air permeable spacer on the rotor 2a side. 4b, 4b,... Are in contact with each other, and the seal fins 2a1, 2a1,... On the rotor 2a side and the air-permeable spacers 4a, 4a,.
And the sealing performance between the stationary blade 2c (refer FIG. 2) and the rotor 2a improves.

  For example, when the pressure of the steam St is lower than a predetermined pressure value, such as in the initial stage of starting the steam turbine 2 (see FIG. 1), the valve control device 100 closes the electromagnetic valve 103 and seal fins 62 on the seal substrate 61 side. , 62,... And the air-permeable spacers 4b, 4b,... On the rotor 2a side are brought into a non-contact state, and the air-permeable properties on the seal fins 2a1, 2a1,. The spacers 4a, 4a, ... are brought into a non-contact state to reduce rotational resistance against rotation of the rotor 2a. The rotor 2a is efficiently rotated by the steam St having a low pressure, and the steam turbine 2 starts up smoothly.

When the steam turbine 2 (see FIG. 2) starts up and the pressure of the steam St becomes equal to or higher than a predetermined pressure value, the valve control device 100 opens the electromagnetic valve 103 and seal fins 62, 62,. .. and the air-permeable spacers 4b, 4b,... On the rotor 2a side are brought into contact with each other, and the seal fins 2a1, 2a1,. ... is brought into contact.
In the steam turbine 2, the sealing performance between the stationary blade 2c (see FIG. 2) and the rotor 2a is improved, and the turbine efficiency is improved.

  That is, in the steam turbine 2 (see FIG. 2), when the pressure of the steam St is lower than a predetermined pressure value, such as in the initial stage of startup, a clearance is generated between the stationary blade 2c (see FIG. 2) and the rotor 2a. Rotational resistance to the rotation of the rotor 2 is reduced, and the rotor 2a efficiently rotates with the steam St and rises smoothly. In the steam turbine 2, when the pressure of the steam St becomes equal to or higher than a predetermined pressure value, the sealing performance between the stationary blade 2c (see FIG. 2) and the rotor 2a is improved, and the turbine efficiency is improved.

The labyrinth seal device 60c shown in FIG. 11 has a configuration in which driving steam flows from the high-pressure steam supply source 102 into the pressurizing chamber 71 and moves the piston head 64 in a direction close to the rotor 2a. A configuration in which the piston head 64 is moved in a direction close to the rotor 2a by a driving means such as an actuator that does not work may be used.
Further, the seal structure (see FIG. 9) incorporated between the nozzle diaphragm outer ring side 80 and the moving blade 2b may have the same configuration as the seal structure shown in FIG.

As described above, the steam turbine 2 (see FIG. 1) according to the present embodiment, as shown in FIG. 3, is between the stationary blade 2c (see FIG. 2) that is a fixed part and the rotor 2a that is a rotating part. The labyrinth seal device 60, the seal fins 2a1, 2a1,... On the rotor 2a side, and the air-permeable spacers 4b, 4b,.
And the seal fins 62, 62, ... on the seal substrate 61 side of the labyrinth seal device 60 are in contact with the air permeable spacers 4b, 4b, ... on the rotor 2a side, and the seal fins 2a1, on the rotor 2a side. 2a1,... Are in contact with the breathable spacers 4a, 4a,. With this configuration, the sealing performance between the stationary blade 2c and the rotor 2a is improved, and an excellent effect is obtained in that a decrease in turbine efficiency due to leaked steam can be suppressed.

  Further, the breathable spacer 4 (4a, 4b) is formed of a breathable metal that is an abradable material having excellent machinability. With this configuration, even if the seal fin 62 and the seal fin 2a1 and the air permeable spacer 4 come into contact with each other, the air permeable spacer 4 is cut so that the seal fin 62 and the seal fin 2a1 can be prevented from being damaged. .

Further, a small amount of steam St can be passed through the breathable spacer 4 made of a breathable metal, and frictional heat generated by the contact between the seal fin 62 and the seal fin 2a1 and the breathable spacer 4 is generated. It is possible to cool with steam St which ventilates. Therefore, it is possible to prevent the breathable spacer 4 from becoming higher than the temperature of the steam St.
For example, even when the rotor 2a rotates for a long time and frictional heat is generated for a long time in the seal fin 62 and the seal fin 2a1 and the air permeable spacer 4, the air permeable spacer 4 does not become higher than the temperature of the steam St. The rotor 2a and the seal substrate 61 to which the air permeable spacer 4 is attached do not become higher than the temperature of the steam St. Therefore, it is possible to prevent the rotor 2a and the seal substrate 61 from being thermally deformed.

For example, the spacer made of a porous metal is an abradable material having excellent machinability, and when the seal fin 62 and the seal fin 2a1 are in contact with the spacer made of the porous metal, the spacer made of the porous metal is cut. Thus, damage to the seal fin 62 and the seal fin 2a1 can be prevented.
However, the pores of the porous metal may not be connected to each other, and the spacer made of the porous metal cannot vent the vapor St. Therefore, the frictional heat generated by the contact between the seal fin 62 and the seal fin 2a1 and the spacer made of the porous metal cannot be cooled by the steam St.
In the present embodiment, by providing the breathable spacer 4 made of a breathable metal, the frictional heat generated by the contact between the seal fins 62 and the seal fins 2a1 and the breathable spacer 4 is generated by the steam St that ventilates the breathable spacer 4. Can be cooled.

  Further, the seal substrate 61 provided with the seal fins 62, 62,... And the air permeable spacers 4a, 4a,... Can be moved in the direction of approaching / separating from the rotor 2a. When the steam St has a low pressure, the seal fins 62, 62,... On the seal substrate 61 side and the air permeable spacers 4b, 4b,. The seal fins 2a1, 2a1,... On the side and the breathable spacers 4a, 4a,.

With this configuration, the seal fins 62, 62,... And the seal fins 2a1, 2a1,... And the breathable spacer 4 when the steam St is at a low pressure, for example, at the start of the steam turbine 2 (see FIG. 1). , 4,... Are in a non-contact state, and the rotational resistance to the rotation of the rotor 2a can be reduced. Therefore, even if the pressure of the steam St is low, the rotor 2a can be rotated efficiently, and the steam turbine 2 can be started up smoothly.
When the load of the steam turbine 2 increases and the pressure of the steam St increases, the seal fins 62, 62,... And the seal fins 2a1, 2a1,. It is possible to improve the sealing performance between the stationary blade 2c (see FIG. 2) and the rotor 2a in the contact state. Therefore, the outstanding effect that the fall of the turbine efficiency of the steam turbine 2 can be suppressed is produced.

Note that, for example, the seal structure including the labyrinth seal device 60, the plurality of seal fins 2a1, and the plurality of air-permeable spacers 4b shown in FIG. 3 is not limited between the nozzle diaphragm inner ring side 70 and the rotor 2a. 2d (see FIG. 2) and the rotor 2a can be incorporated between the other fixed part and the rotating part.
Further, the labyrinth seal device 60 to which the seal fins 62, 62,... And the breathable spacers 4a, 4a,. Even if it exists, the effect of cooling by the vapor | steam St ventilating the air permeable spacers 4,4, ... can be acquired.

1 Power Plant 2 Steam Turbine 2a Rotor (Rotating part)
2a1, 2a5, 2g1, 62 Seal fin (seal structure)
2b Rotor blade (rotating part)
2c Stator blade (fixed part)
2d casing (fixed part)
2g Cover 4 (4a, 4b) Breathable spacer (spacer, seal structure)
60, 60a, 60b, 60c, 90 Labyrinth seal device (seal structure)
61, 61a, 91 Seal substrate (movable part)
64, 92 Piston head (movable part)
65,93 Piston body (movable part)
66, 94 Return spring (biasing means)
66a Compression spring (biasing means)
71, 81 Pressurizing chamber (drive device)
72, 82 Steam passage 100 Valve control device (drive device)
101 Operating state detection device (rotation speed detection device, pressure detection device)
102 High-pressure steam supply source (drive device)
103 Solenoid valve (drive device)
St steam

Claims (9)

A rotating part composed of a rotor and a member that rotates integrally with the rotor;
Incorporated in a steam turbine having a casing containing the rotating part and a fixing part made of a member fixed to the casing;
A seal fin is provided in both or any one of the rotating part and the fixed part,
A seal structure including a spacer made of a breathable metal in both or any one of the rotating part and the fixed part,
The seal fin provided in the rotating part and the spacer provided in the fixed part face each other, and the seal fin provided in the fixed part and the spacer provided in the rotary part face each other,
When the seal fin is provided in the fixed portion, the seal fin provided in the fixed portion is movable in a direction approaching / separating from the rotating portion, and the seal fin is adjacent to the rotating portion. Contact with the opposing spacer when moved in the direction of
When the spacer is provided in the fixed part, the spacer provided in the fixed part is movable in a direction approaching / separating from the rotating part, and the spacer is in a direction approaching the rotating part. Contact with the opposing seal fin when moved,
The spacer causes the steam supplied through the clearance between the fixed part and the rotating part to pass through the clearance in an amount that can maintain the temperature of the spacer at a temperature equivalent to that of the steam flowing in the casing. The seal structure characterized by being comprised. The member fixed to the casing is a stationary blade provided in the casing,
The seal fin is provided at both or any one of the tip of the stationary blade and the position of the rotor facing the tip of the stationary blade,
The spacer is provided at both or any one of the tip of the stationary blade and the position of the rotor facing the tip of the stationary blade,
In the case where the tip of the stationary blade is provided with the seal fin, the seal fin provided at the tip of the stationary blade is movable in a direction approaching / separating from the rotor,
The seal according to claim 1, wherein when the spacer is provided at the tip of the stationary blade, the spacer provided at the tip of the stationary blade is movable in a direction approaching or separating from the rotor. Construction. The member that rotates integrally with the rotor is a rotor blade provided in the rotor,
The seal fin is provided at both or any one of the position of the casing facing the tip of the rotor blade and the tip of the rotor blade,
The position of the casing facing the tip of the moving blade, and the tip of the moving blade, the spacer is provided at both or any one of them,
When the seal fin is provided in the casing, the seal fin provided in the casing is movable in a direction approaching / separating from a tip of the moving blade,
2. The seal structure according to claim 1, wherein, when the spacer is provided in the casing, the spacer provided in the casing is movable in a direction approaching / separating from a tip of the moving blade. The fixed part is provided with a movable part that is urged in a direction away from the rotating part by an urging means, and is movable in a direction close to the rotating part by the pressure of steam flowing through the steam turbine,
When the fixed portion is provided with the seal fin, the seal fin provided in the fixed portion is attached to the movable portion,
When the fixed part is provided with the spacer, the spacer provided in the fixed part is attached to the movable part,
When the pressing force that moves the pressure of the steam in the direction in which the movable part is moved closer to the rotating part is smaller than the urging force that the urging means urges the movable part in a direction away from the rotating part, The movable part moves to a position away from the rotating part, the seal fin and the spacer facing each other are in a non-contact state,
2. The device according to claim 1, wherein when the pressing force is greater than or equal to the urging force, the movable portion moves to a position close to the rotating portion, and the seal fin and the spacer facing each other are in contact with each other. The seal structure according to claim 3. The fixed portion is provided with a movable portion that is urged in a direction away from the rotating portion by an urging means and is movable in a direction in proximity to the rotating portion,
When the fixed portion is provided with the seal fin, the seal fin provided in the fixed portion is attached to the movable portion,
When the fixed part is provided with the spacer, the spacer provided in the fixed part is attached to the movable part,
An operation state detection device for detecting an operation state of the steam turbine;
And a driving device that moves the movable part in a direction close to the rotating part,
The drive device moves the movable portion in a direction approaching the rotating portion based on the operation state of the steam turbine detected by the operation state detection device, and brings the seal fin and the spacer facing each other into a contact state. The seal structure according to any one of claims 1 to 3, wherein the seal structure is provided. The operation state detection device is a rotation speed detection device that detects the rotation speed of the rotor, and detects the operation state of the steam turbine based on the rotation speed of the rotor,
The seal structure according to claim 5, wherein the driving device moves the movable portion in a direction approaching the rotating portion when a rotation speed of the rotor is equal to or higher than a predetermined rotation speed. The operating state detecting device is a pressure detecting device that detects a pressure of steam flowing through the steam turbine, and detects an operating state of the steam turbine based on the pressure of the steam,
The seal structure according to claim 5, wherein the driving device moves the movable portion in a direction approaching the rotating portion when the pressure of the steam is equal to or higher than a predetermined pressure value. A rotating part composed of a rotor and a member that rotates integrally with the rotor;
Incorporated in a steam turbine having a casing containing the rotating part and a fixing part made of a member fixed to the casing;
A seal fin is provided in both or any one of the rotating part and the fixed part,
Provided with a spacer made of a breathable metal in both or any one of the rotating part and the fixed part,
The seal fin provided in the rotating part and the spacer provided in the fixed part face each other, and the seal fin provided in the fixed part and the spacer provided in the rotary part face each other,
The spacer is configured to vent the steam supplied through the clearance between the fixed part and the rotating part in an amount capable of maintaining the temperature of the spacer at a temperature equivalent to the steam flowing in the casing. Configured,
The fixed part is provided with a movable part that is urged in a direction away from the rotating part by an urging means, and is movable in a direction close to the rotating part by a driving device,
When the fixed portion is provided with the seal fin, the seal fin provided in the fixed portion is attached to the movable portion,
When the fixed part is provided with the spacer, the spacer provided in the fixed part is a control method of a seal structure attached to the movable part,
Detecting the rotation speed of the rotating part;
When the rotational speed of the rotating part is equal to or higher than a predetermined rotational speed, the moving part is moved in a direction close to the rotating part, and
When the rotational speed of the rotating part is equal to or higher than the predetermined rotational speed, the seal fin and the spacer facing each other are brought into contact with each other. A rotating part composed of a rotor and a member that rotates integrally with the rotor;
Incorporated in a steam turbine having a casing containing the rotating part and a fixing part made of a member fixed to the casing;
A seal fin is provided in both or any one of the rotating part and the fixed part,
Provided with a spacer made of a breathable metal in both or any one of the rotating part and the fixed part,
The seal fin provided in the rotating part and the spacer provided in the fixed part face each other, and the seal fin provided in the fixed part and the spacer provided in the rotary part face each other,
The spacer is configured to vent the steam supplied through the clearance between the fixed part and the rotating part in an amount capable of maintaining the temperature of the spacer at a temperature equivalent to the steam flowing in the casing. Configured,
The fixed part is provided with a movable part that is urged in a direction away from the rotating part by an urging means, and is movable in a direction close to the rotating part by a driving device,
When the fixed portion is provided with the seal fin, the seal fin provided in the fixed portion is attached to the movable portion,
When the fixed part is provided with the spacer, the spacer provided in the fixed part is a control method of a seal structure attached to the movable part,
Detecting a pressure of steam flowing through the steam turbine;
When the pressure of the steam is equal to or higher than a predetermined pressure value, the procedure of moving the movable part in a direction close to the rotating part,
A control method of a seal structure, wherein the seal fin and the spacer facing each other are brought into contact with each other when the steam pressure is equal to or higher than the predetermined pressure value.

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