JP2004245187A - Non-contact seal device for turbo machine and steam turbine equipment using this device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a non-contact seal device for a turbo machine, capable of improving sealability at the time of a steady motion operation, and reducing risk of a contact between a rotating structure and a stationary structure at the time of a low load accompanying start and stop, and reducing damage occurring on the rotating structure side even if a contact occurs and to provide a steam turbine plant provided with the non-contact seal. <P>SOLUTION: This device includes seal fins 4, 6 which are provided at a gap between the rotating structure 5 and the stationary structure 2 in the turbo machine and of which the axial pitch is set at and less than a fluctuation in a thermal expansion difference of the turbo machine, and a radial clearance control system which includes a clearance between the front end of the rotating side seal fin 6 and the front end of the stationary side seal fin 4 in the radial direction at the time of starting or stopping the turbo machine, and which moves the seal fin on the stationary side in the radial direction so as to form a dislocation between the front end of the rotating side seal fin 6 and the front end of the stationary side seal fin 4 in the radial direction at the time of the steady motion operation. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a non-contact sealing device that seals in a non-contact manner so that fluid does not leak from a gap between a rotating structure and a stationary structure in a turbomachine, and a steam turbine facility including the non-contact sealing device.
[0002]
[Prior art]
A description will be given taking a steam turbine, which is a typical example of a turbomachine, as an example.
The steam turbine is mainly composed of a rotating rotor, moving blades implanted in the rotor, stationary vanes (also referred to as nozzles) disposed between the moving blades, and a casing containing these. ing. More specifically, the rotor blades are implanted so as to form a cascade of several tens to hundreds or more blades in the collecting direction of the rotor, and are also subjected to pressure and temperature conditions of steam flowing therethrough in the axial direction. In total, about 5 to 10 rows of cascades having different wing lengths are arranged. On the other hand, the stationary blade (nozzle) is sandwiched by a ring-shaped member called a nozzle diaphragm, and an outer ring thereof is fixed to a casing. The stationary blades are disposed between the blade rows of the moving blades, and form a paragraph by a pair of the moving blades and the stationary blades. Furthermore, this paragraph is composed of several stages to about ten stages to constitute a high-pressure, medium-pressure or low-pressure turbine. Then, when high-temperature and high-pressure steam flows through this stage, the heat energy of the steam is converted into rotational energy of the rotor between each stage, and the generator connected by the rotor is rotated.
[0003]
Therefore, a gap is provided between the stator vane and the rotor to enable rotation of the rotor, but steam flowing into the stator vane flows from this gap as leakage steam that bypasses the stator vane and flows into the turbine. In order to reduce the amount of leaked steam, a labyrinth seal having a non-contacting seal fin is provided at a portion where the inner ring of the stationary blade is close to the rotor because the leakage steam amount is reduced.
[0004]
As such a labyrinth seal, a staggered type or comb type labyrinth seal is conventionally known. A steam turbine is a rotating machine that uses high-temperature steam and rotates the rotor at high speed.In order to improve the performance of the turbine, the steam turbine, which is a working fluid, flows into the stationary blades and the moving blades as much as possible. It is necessary to minimize the amount of steam leaking through the gap between the stator blade inner ring, the gap between the rotor blade tip and the stator blade outer ring, or the gap between the rotor blade tip and the casing. Since the steam turbine is a high-speed rotating machine and it is difficult to apply a contact-type sealing device, the non-contact labyrinth seal as described above is applied to the seal between the rotating structure and the stationary structure of the steam turbine. Have been.
[0005]
FIGS. 22A, 22B, 22C and 22D show a conventional labyrinth seal. In the figure, reference numeral 9 denotes an inner ring of a stator vane ring 8 (the stator vane ring is sometimes referred to as a nozzle diaphragm) fitted to and attached to a casing (not shown), that is, a stator vane inner ring. A packing ring 2 is usually attached to the periphery via an elastic body 11 such as a leaf spring, and a processed seal fin 4 formed integrally with or separately from the packing ring 2 extends toward the inner diameter side. ing.
[0006]
In FIG. 22 (c), reference numeral 5a denotes a turbine shaft which is a part of a rotary structure. A plurality of disk-shaped convex portions 6a are formed on the surface of the turbine shaft 5a, and the stationary structure faces the turbine shaft 5a. In the packing ring 2, a low seal fin 44 corresponding to the convex portion 6 a of the turbine shaft 5 a and a high seal fin 45 corresponding to the concave portion 60 of the turbine shaft 5 are formed.
[0007]
A non-contact type shaft sealing device having such a basic structure is generally called a labyrinth seal 15, in which the radial gap 7 at the tips of the seal fins 44, 45 is minutely set, and this radius is bypassed to the stator vane. The steam 3 leaking through the directional gap 7 is reduced to reduce the leakage loss.
[0008]
As described above, the non-contact sealing device for the gap between the inner ring of the stationary blade and the turbine shaft has been described. However, the gap between the tip of the moving blade and the outer ring of the stationary blade or the casing has a similar problem. FIGS. 23 (a), 23 (b), 23 (c) and 23 (d) show a non-contact sealing device for a gap between a moving blade tip and a stationary blade outer ring of a steam turbine conventionally applied. That is, a radial gap 18 is provided between the shroud cover 21 provided at the tip 16 of the moving blade 14 and the outer ring 17 of the stationary blade 12 or between the casing and a casing (not shown) in order to allow the rotating blade 14 to rotate. Is provided. For this reason, a part of the steam flowing into the moving blade 14 flows from the radial gap 18 as the leaking steam 3 that bypasses the moving blade 14, which is one of the causes of lowering the turbine performance. In order to reduce the leaked steam 3, a seal fin 19 is provided on a stationary blade outer ring 17 (or casing) close to a shroud cover 21 provided on the moving blade tip 16.
[0009]
FIG. 24 shows a typical example of a conventional staggered labyrinth seal device. In the figure, reference numeral 9 denotes an inner ring of a stator vane ring 8 (the stator vane ring is sometimes referred to as a nozzle diaphragm) fitted to and attached to a casing (not shown), that is, a stator vane inner ring. A packing ring 2 is usually attached to the circumference via an elastic body 11 such as a leaf spring, and a plurality of rows of seal fins 4 formed integrally with or separately from the packing ring 2 extend from the packing ring 2 toward the inner diameter side. ing. In the figure, reference numeral 5 denotes a rotor which is a part of a rotating structure. In a staggered labyrinth, a plurality of rows of seal fins 6 are formed on the surface of the rotor 5 integrally or separately therefrom.
[0010]
The non-contact type sealing device having such a structure is also called a labyrinth seal, in which the radial gap 7 at the tip of the seal fin 4 is set minutely, bypasses the vane, and passes through the radial gap 7. The amount of leaking steam 3 is reduced to reduce the leakage loss. In the staggered labyrinth, the seal fins 4 of the packing ring 2, which is a stationary structure facing the rotor 5, are formed so as to be staggered and combined with the seal fins 6 of the rotor. The radial gaps 7 and 10 at the tips of and 6 are minutely set, and the steam 3 that leaks through the radial gaps 7 and 10 by bypassing the stationary blades is reduced to reduce the leakage loss.
[0011]
The sealing device for the gap between the inner ring of the stator vane and the rotor has been described above. However, the gap between the tip of the rotor blade and the outer ring of the stator blade or the casing has the same problem. FIGS. 25A and 25B show a typical example of a staggered labyrinth seal device provided between a moving blade tip 16 and a stationary blade outer ring 17 of a steam turbine conventionally applied. That is, a gap is provided between the shroud cover 21 provided at the tip 16 of the moving blade 14 and the outer ring 17 of the stationary blade 12 or a casing (not shown) in order to allow the rotating blade 14 to rotate. ing. For this reason, a part of the steam flowing into the moving blades 14 flows as leaked steam that bypasses the moving blades 14 from this gap, which is one of the causes of lowering the turbine performance.
[0012]
In order to reduce the leakage steam, in the staggered labyrinth seal device at the blade tip portion, a plurality of rows of seals are provided on the stationary blade outer ring 17 (or casing) near the shroud cover 21 provided at the blade tip 16. Fins 19 are provided, and seal fins 24 formed on the outer surface of the shroud cover 21 so as to be staggered and interdigitated with seal fins 19 provided on the stator vane outer ring. , 24, the radial gaps 18 and 23 at the tips are set to be minute, and the steam 3 leaking through the radial gaps 18 and 23 bypassing the vane 12 is reduced to reduce the leakage loss.
[0013]
A combined direct labyrinth seal device called a comb labyrinth shown in FIG. 26 is also a non-contact seal for reducing the amount of leaked steam between the rotating structure and the stationary structure of the steam turbine, similarly to the staggered labyrinth seal device. It has been applied as a device.
[0014]
Incidentally, the sealing performance of the labyrinth seal device as shown in FIGS. 22 to 26 is generally improved by reducing the radial gap at the tip of the seal fin. On the other hand, when a so-called rubbing phenomenon in which a rotating structure comes into contact with a stationary structure due to an excessively small radial gap at the tip of the seal fin of the labyrinth seal device due to, for example, excessive thermal deformation of the casing, the axial vibration of the turbine occurs. May cause excessive shaft vibration that makes it difficult to continue the operation of the turbine.
[0015]
As described above, one method of further improving the sealing performance of the labyrinth seal device is to narrow its radial gap. The cat back phenomenon, the difference in the amount of thermal expansion between the casing and stator blades and the rotor and rotor blades, the deformation of the rotating structure due to centrifugal force, the movement of the rotor shaft center due to the bearing oil film, the alignment change, and the occurrence of shaft vibration It can be said that the current radial gap setting is a minimum gap setting for preventing a hard rubbing phenomenon from occurring, and a significant improvement in sealing performance cannot be expected with a conventional labyrinth seal.
[0016]
On the other hand, in recent years, a radial gap control method of a labyrinth seal device has been invented, and a clearance control system aiming at improving the sealing performance of a non-contact labyrinth seal device may be applied to a steam turbine (for example, Patent Document 1). , 2).
[0017]
[Patent Document 1]
JP-B-49-29975
[Patent Document 2]
U.S. Pat. No. 4,436,311
[0018]
As shown in FIGS. 27 (a) and (b) applied to a staggered labyrinth seal device, this clearance control system has a radius at the tip of the seal fin at the start and stop (a) where rubbing is most concerned. The directional gap is set wide to avoid rubbing, and at high turbine load (b), where high sealing performance is required, the labyrinth on the stationary side is extruded in the radial direction to use the clearance gap between the seal fin tip and the clearance control system. It is intended to improve the sealing performance when the turbine is under a high load by setting a smaller value than when the turbine is not loaded.
[0019]
In recent years, higher performance of steam turbines has been demanded more than ever, and daily improvements have been made to improve the performance of steam turbines, such as various improvements such as performance improvement of stator vanes and moving blades and reduction of exhaust loss. Have been. Among these improvements, improved sealing performance, which minimizes the amount of steam leaking through the gap between the rotor and stator inner ring and the gap between the rotor blade tip and stator outer ring, greatly contributes to the improvement of turbine performance. Is what you do.
[0020]
[Problems to be solved by the invention]
As described above, in the labyrinth seal device as shown in FIGS. 22 to 26, generally, if the radial gap at the tip of the seal fin is reduced, the annular area of the gap of the seal portion is reduced, so that the sealing performance is improved. Further, the sealing performance of the labyrinth sealing device is generally improved by increasing the number of rows of seal fins.
[0021]
On the other hand, if the so-called rubbing phenomenon in which the rotating structure comes into contact with the stationary structure due to excessive thermal deformation of the casing occurs due to the radial gap at the tip of the seal fin of the labyrinth seal device being too small, the axial vibration of the turbine is reduced. This may cause a drastic change and cause excessive shaft vibration that makes it difficult to continue the operation of the turbine.
[0022]
As described above, in order to further improve the sealing performance of the labyrinth seal device, it is required to reduce the radial gap. However, for steam turbines, the cattle phenomena and reverse cattle phenomena caused by uneven temperature distribution of the casing due to startup and shutdown, differences in the amount of thermal expansion between the casing and stationary blades and the rotor and rotor blades, and deformation of the rotating structure due to centrifugal force Since the rotor oil axis causes movement of the rotor shaft center, changes in alignment, and shaft vibration due to the bearing oil film, the current radial gap setting is the minimum gap setting to prevent a hard rubbing phenomenon. A significant improvement in sealing performance cannot be expected with conventional labyrinth seals.
[0023]
When the seal fin 4 comes into contact with a part of the circumference of the rotor 5, the temperature of the contact portion of the rotor 5 rises, a temperature distribution is generated near the contact portion of the rotor 5, and the contact portion thermally expands due to high temperature. The rotor 5 is slightly deformed. Therefore, once the rubbing phenomenon occurs, the contact portion greatly expands due to a rise in the temperature of the contact portion of the rotor 5, and the rotor 5 is bowed such that a part of the circumference of the rotor 5 that contacts particularly strongly is convex. Deform. In this case, the contact is further strengthened, leading to a hard rubbing phenomenon, causing excessive vibration to stop the operation of the turbine, causing permanent contact due to thermal stress at the contact portion of the rotor 5, causing rotor contact, There is a problem that the residual strain due to the melting of the portion or the like is generated as a permanent strain, and the rotor 5 is permanently bent.
[0024]
The labyrinth seal device provided at the tip of the rotor blade 14 shown in FIG. 25 changes the radial gap 18 similarly to the labyrinth seal device of the rotor 5, and depending on the degree of the change, the stator blade outer ring 17 May come into contact with the shroud cover 21 provided on the blade tip 16. In this case, similarly to the labyrinth seal device of the rotor 5, turbine shaft vibration is generated, which affects the reliability of the steam turbine. Further, when contact occurs, the temperature of the contact portion rises due to the generation of frictional heat. However, since the rotor blade 14 is a rotating object and a strong centrifugal force acts on the rotating blade 14, the shroud cover 21 The temperature becomes high due to frictional heat caused by contact. The shroud cover 21 whose material strength has been reduced due to high temperature is deformed by centrifugal force and swells in the radial direction, and the contact is further strengthened, leading to a hard rubbing phenomenon, causing excessive vibration and causing the turbine operation to be stopped. There is a problem that permanent shrinkage may occur in the shroud cover 21.
[0025]
As one of the solutions to such a problem, a clearance control system is sometimes applied. In this case, it is possible to reduce a radial gap at a high turbine load. Effective for improving performance. However, even when the turbine is under high load, the steam turbine has some rotor shaft vibration, eccentricity, or thermal deformation of the casing, and even if the clearance control system is applied, the radial gap at the time of high turbine load is secured. It is necessary to keep it, and further improvement of performance is not expected.
[0026]
If the radial gap of the labyrinth seal device is set to the minimum and cannot be further reduced, it is conceivable to increase the number of rows of seal fins as a measure for improving the performance of the labyrinth seal device. However, in a turbomachine that handles a high-temperature fluid such as a steam turbine, the difference between the temperature distribution of the rotor and the temperature distribution of the casing causes a difference in thermal expansion between the rotor and the casing. It is a difficult situation.
[0027]
Since a steam turbine is a mechanical device for converting steam heat energy into mechanical energy such as rotation of a turbine rotor by introducing high-temperature steam of about 500 ° C. to 600 ° C., more recently 600 ° C. or more, Machine exposed to A rotor, which is a rotating structure of a steam turbine, is smaller in size and weight than a casing of a stationary structure, and has a smaller heat capacity than the casing. Further, the rotor, which is a rotating structure, also has a higher heat transfer coefficient than the casing. Therefore, when high-temperature steam flows into the turbine when the steam turbine is started, the temperature of the rotor becomes faster than that of the casing. As a result, during the start-up operation, the rotating seal fins 6 and the stationary seal fins 4 which have the positional relationship as shown in FIG. The amount of thermal expansion of the rotor 5 becomes larger than the amount of thermal expansion of the casing, and the relative position in the turbine axial direction changes. This state is called a rotor long state. Generally, this relative displacement is referred to as a differential elongation, and increases as the distance from a thrust bearing (not shown), which is a displacement constraint position of the rotor, increases, and as the steam temperature increases.
[0028]
When the load on the turbine increases and the operation becomes steady, the temperature difference between the rotor and the casing becomes smaller as shown in FIG. Approach. This state is called a steady state. On the other hand, when the load decreases toward the stop of the turbine, low-temperature steam flows into the turbine and the temperature of the rotor decreases rapidly, whereas the temperature of the casing decreases slowly, and the amount of thermal expansion of the rotor decreases. As the thermal expansion of the casing becomes smaller, the difference in elongation becomes smaller, and a difference in elongation in the opposite direction occurs as shown in FIG. This state is called a rotor short state.
[0029]
In the staggered labyrinth seal device conventionally used, in a situation where a large difference in elongation occurs in a rotor long state or a rotor short state such as when starting or stopping the turbine, FIG. In order to prevent the seal fins 6 on the rotating side and the seal fins 4 on the stationary side from coming into contact in the axial direction as shown in FIG. Therefore, the pitch of the seal fins 4 and 6 is set to a value larger than the sum of the maximum difference in extension in the rotor long state and the maximum difference in extension in the rotor short state, that is, the fluctuation range of the difference in extension. As described above, in the conventional staggered labyrinth sealing device, the minimum value of the seal fin pitch is limited by the difference in the axial elongation of the turbine, and the minimum seal fin pitch is usually adopted from the viewpoint of ensuring the sealing performance. Therefore, it is difficult to improve the sealing performance by greatly increasing the number of rows of seal fins.
[0030]
In the conventionally applied clearance control system, the seal fin pitch of the labyrinth remains the same, and only the improvement of the sealing performance by changing the radial gap is considered. That is, the improvement of the sealing performance in the labyrinth sealing device applied to the steam turbine is limited, and the further improvement of the sealing performance is difficult.
[0031]
Therefore, the present invention provides a high sealing performance during steady operation, a low risk of contact between the rotating structure and the stationary structure at low load due to startup and shutdown, and a reduction in the rotating structure side in the event of contact. It is an object of the present invention to provide a non-contact seal device for a turbomachine which causes less damage to a steam turbine and a steam turbine facility provided with the non-contact seal device.
[0032]
[Means for Solving the Problems]
In order to solve the above problem, a non-contact sealing device for a turbo machine according to the invention according to claim 1 is provided in the rotating structure and the stationary structure in a gap between the rotating structure and the stationary structure of the turbo machine in an axial direction. Seal fins whose pitch is set to be equal to or smaller than the fluctuation width of the thermal expansion difference in the axial direction of the turbomachine, the tip of the rotating seal fin and the tip of the stationary seal fin when the turbomachine starts or stops. Have a gap in the radial direction, and move the stationary-side seal fins in the radial direction so that the tip of the rotary-side seal fin and the distal end of the stationary-side seal fin form a stagger in the radial direction during steady operation. The system is provided with a radial clearance control system.
[0033]
ADVANTAGE OF THE INVENTION According to this invention, the sealing performance at the time of a steady operation is high, the danger of the contact between a rotating structure and a stationary structure at the time of low load accompanying a start / stop is low, and the rotating structure in the event of contact It is possible to provide a non-contact sealing device for a turbomachine with little damage on the side.
[0034]
According to a second aspect of the present invention, in the first aspect, the rotating side seal fin and the stationary side seal fin form a staggered labyrinth, and the height of the rotating side seal fin is equal to the height of the stationary side seal fin. It is characterized in that it is configured to be higher than.
[0035]
ADVANTAGE OF THE INVENTION According to this invention, the non-contact sealing apparatus of a turbo machine with little danger that a stationary side seal fin contacts a rotary structure and a rotary structure is overheated can be provided.
[0036]
According to a third aspect of the present invention, in the first aspect of the present invention, the stationary side seal fin and the rotary side seal fin form a comb labyrinth having the same or substantially the same axial pitch, and the height of the rotary side seal fin is reduced. It is configured such that the height of the rotating side seal fin is lower than the height of the stationary side seal fin while the average gap at the tip of the stationary side seal fin is three times or more during the turbine high load operation. It is characterized by having.
[0037]
ADVANTAGE OF THE INVENTION According to this invention, the non-contact sealing apparatus of a turbo machine with little danger that a stationary side seal fin contacts a rotary structure and a rotary structure is overheated can be provided.
[0038]
According to a fourth aspect of the present invention, in the second or third aspect of the present invention, the stationary seal fin is located upstream of the center of the rotary seal fin pitch during a high load operation of the turbomachine. It is characterized by.
ADVANTAGE OF THE INVENTION According to this invention, sealability can be improved, without increasing the number of seal fins and reducing the radial gap of the seal fin tip.
[0039]
The invention according to claim 5 has a rated output of 80 MW or more, the main steam has a steam pressure of 10 MPa or more and a steam temperature of 500 ° C. or more, and the rotor from the high-pressure turbine to the low-pressure turbine is inseparably integrated. It consists of a high-low pressure rotor formed in, or a high-low pressure rotor made by mechanically joining a high-pressure turbine or a high-medium-pressure turbine rotor and a low-pressure turbine rotor manufactured separately from each other, In a high- and low-pressure integrated steam turbine facility in which a turbine stage from a high-pressure portion to a low-pressure portion of the rotor is housed in one turbine casing, and the turbine stages form a steam passage having a single-flow structure, the turbine stage has a structure in which 5. A radial clearance controller provided with the non-contact sealing device for a turbomachine according to any one of claims 5 to 7. When the turbomachine is started and stopped or when operating at extremely low load, there is a gap in the radial direction between the tip of the rotating seal fin and the tip of the stationary seal fin. When the thrust bearing is located near the shaft end on the high pressure turbine side, the seal fin pitch on the rotating side or stationary side of the labyrinth of the high pressure stage is controlled so that the tip of the side seal fin and the tip of the side seal fin form a stagger in the radial direction. Is set to 8 mm or less, and the seal fin pitch of the labyrinth of the low-pressure paragraph is set to 14 mm or less.
[0040]
ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to reduce the leakage flow rate of a seal part without causing generation | occurrence | production of rubbing in the seal part of a steam turbine, and to provide a high-performance, safe and highly reliable steam turbine equipment. Can be.
[0041]
The invention according to claim 6 has a rated output of 100 MW or more, the main steam has a steam pressure of 10 MPa or more and a steam temperature of 520 ° C. or more, and has a high-pressure turbine, an intermediate-pressure turbine, and a low-pressure turbine. The low-pressure turbine rotor and the low-pressure turbine rotor are composed of a medium-to-low pressure rotor integrally formed so as not to be disassembled, or the medium-pressure turbine rotor and the low-pressure turbine rotor manufactured separately from each other are mechanically joined. A high-pressure turbine rotor made of a single medium-to-low pressure rotor, and a rotor of a high-pressure turbine manufactured separately from the medium-to-low pressure rotor is mechanically joined to the medium-to-low pressure rotor to form a single rotor; Are stored in a high-pressure turbine casing, and the turbine stages of the middle and low pressure parts are stored in a medium- and low-pressure turbine casing separate from the high-pressure turbine casing. In a steam turbine facility for forming a steam passage, a turbine stage is provided with a non-contact seal device for a turbomachine according to any one of claims 1 to 5, and a turbo clearance is provided by a radial clearance control system provided in the non-contact seal device. At the start and stop of the machine and at extremely low load operation, there is a gap in the radial direction between the tip of the rotating seal fin and the tip of the stationary seal fin. The tip and the tip are controlled to form a stagger in the radial direction, and when the thrust bearing is located near the shaft end on the high-pressure turbine side, the seal fin pitch on the rotating side or stationary side of the labyrinth of the high-pressure stage is set to 8 mm or less, In addition, the seal fin pitch of the labyrinth in the low-pressure paragraph is set to 14 mm or less.
[0042]
ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to reduce the leakage flow rate of a seal part without causing generation | occurrence | production of rubbing in the seal part of a steam turbine, and to provide a high-performance, safe and highly reliable steam turbine equipment. Can be.
[0043]
The invention according to claim 7 has a rated output of 100 MW or more, the main steam has a steam pressure of 10 MPa or more and a steam temperature of 520 ° C. or more, and has a high-pressure turbine, an intermediate-pressure turbine, and a low-pressure turbine. The low-pressure turbine rotor and the low-pressure turbine rotor are composed of a medium-to-low pressure rotor integrally formed so as not to be disassembled, or the medium-pressure turbine rotor and the low-pressure turbine rotor manufactured separately from each other are mechanically joined. A high-pressure turbine rotor made of a single medium-to-low pressure rotor, and a rotor of a high-pressure turbine manufactured separately from the medium-to-low pressure rotor is mechanically joined to the medium-to-low pressure rotor to form a single rotor; Are stored in a high-pressure turbine casing, and the turbine stages of the middle and low pressure parts are stored in a medium- and low-pressure turbine casing separate from the high-pressure turbine casing. In a steam turbine facility for forming a steam passage, a turbine stage is provided with a non-contact seal device for a turbomachine according to any one of claims 1 to 5, and a turbo clearance is provided by a radial clearance control system provided in the non-contact seal device. At the start and stop of the machine and at extremely low load operation, there is a gap in the radial direction between the tip of the rotating seal fin and the tip of the stationary seal fin. When the thrust bearing is located between the high-pressure turbine and the intermediate-pressure turbine, the seal fins on the rotating side or stationary side of the labyrinth of the high-pressure stage and the intermediate-pressure stage are controlled so that the tip and the tip form a stagger in the radial direction. The pitch is 8 mm or less, and the pitch of the labyrinth seal fins in the low-pressure stage is 12 mm or less. To.
[0044]
ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to reduce the leakage flow rate of a seal part without causing generation | occurrence | production of rubbing in the seal part of a steam turbine, and to provide a high-performance, safe and highly reliable steam turbine equipment. Can be.
[0045]
The invention according to claim 8 has a rated output of 120 MW or more, the main steam has a steam pressure of 10 MPa or more and a steam temperature of 520 ° C. or more, and has a high-pressure turbine, a medium-pressure turbine, and a low-pressure turbine. The rotor of the turbine and the medium pressure turbine is composed of a high and medium pressure rotor integrally formed so as not to be disassembled, and the rotor of the low pressure turbine manufactured separately from the high and medium pressure rotor is mechanically joined to the high and medium pressure rotor. One rotor is constituted, a turbine stage of a high-to-medium pressure part is stored in a high-to-medium-pressure turbine casing, a turbine stage of a low-pressure part is stored in a low-pressure turbine casing separate from the high-to-medium-pressure turbine casing, and a low-pressure turbine In a steam turbine facility forming a steam passage having a structure, a non-contact seal device for a turbomachine according to any one of claims 1 to 5 is provided in a turbine stage. In addition, the radial clearance control system provided in the non-contact seal device has a gap between the tip of the rotating seal fin and the tip of the stationary seal fin in the radial direction when the turbomachine starts and stops or operates at a very low load. During high-load operation, the tip of the rotating-side seal fin and the tip of the stationary-side seal fin are controlled so as to form a stagger in the radial direction. When the thrust bearing is located near the shaft end on the high-pressure turbine side, The seal fin pitch of the rotating side or stationary side of the labyrinth of the paragraph is set to 8 mm or less, and the seal fin pitch of the labyrinth of the low-pressure paragraph stored in the first low-pressure turbine casing close to the thrust bearing is set to 16 mm or less. .
[0046]
ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to reduce the leakage flow rate of a seal part without causing generation | occurrence | production of rubbing in the seal part of a steam turbine, and to provide a high-performance, safe and highly reliable steam turbine equipment. Can be.
[0047]
The invention according to claim 9 has a rated output of 120 MW or more, the main steam has a steam pressure of 10 MPa or more and a steam temperature of 520 ° C. or more, and has a high-pressure turbine, a medium-pressure turbine, and a low-pressure turbine. The rotor of the turbine and the medium pressure turbine is composed of a high and medium pressure rotor integrally formed so as not to be disassembled, and the rotor of the low pressure turbine manufactured separately from the high and medium pressure rotor is mechanically joined to the high and medium pressure rotor. One rotor is constituted, a turbine stage of a high-to-medium pressure part is stored in a high-to-medium-pressure turbine casing, a turbine stage of a low-pressure part is stored in a low-pressure turbine casing separate from the high-to-medium-pressure turbine casing, and a low-pressure turbine In a steam turbine facility forming a steam passage having a structure, a non-contact seal device for a turbomachine according to any one of claims 1 to 5 is provided in a turbine stage. In addition, the radial clearance control system provided in the non-contact seal device has a gap between the tip of the rotating seal fin and the tip of the stationary seal fin in the radial direction when the turbomachine starts and stops or operates at a very low load. During high-load operation, the tip of the rotating-side seal fin and the tip of the stationary-side seal fin are controlled to form a stagger in the radial direction, and when the thrust bearing is located between the high-medium pressure turbine and the low pressure turbine, A configuration in which the seal fin pitch of the rotating side or the stationary side of the labyrinth of the high-pressure stage is 12 mm or less, and the seal fin pitch of the labyrinth of the low-pressure stage stored in the first low-pressure turbine casing close to the thrust bearing is 10 mm or less. I do.
[0048]
ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to reduce the leakage flow rate of a seal part without causing generation | occurrence | production of rubbing in the seal part of a steam turbine, and to provide a high-performance, safe and highly reliable steam turbine equipment. Can be.
[0049]
A non-contact seal device for a turbomachine according to the invention according to claim 10, wherein a disc is provided alternately along the rotation axis of the rotary structure on the surface of the rotary structure in a gap between the rotary structure and the stationary structure of the turbomachine. A high convex portion and a low convex portion, and a low seal fin and a high seal fin provided on the stationary structure side facing the high convex portion and the low convex portion.
[0050]
ADVANTAGE OF THE INVENTION According to this invention, the sealing performance at the time of a steady operation is high, the danger of the contact between a rotating structure and a stationary structure at the time of low load accompanying a start / stop is low, and the rotating structure in the event of contact It is possible to provide a non-contact sealing device for a turbomachine with little damage on the side.
[0051]
According to an eleventh aspect of the present invention, in the invention of the tenth aspect, the radial gap formed by the high convex portion provided on the rotating structure and the low seal fin provided on the stationary structure is provided on the rotating structure. The clearance is set to be smaller than the radial gap formed by the low convex portion and the high seal fin provided on the stationary structure.
ADVANTAGE OF THE INVENTION According to this invention, high sealing performance can be obtained at the time of high load operation of a turbomachine.
[0052]
A non-contact sealing device for a turbomachine according to a twelfth aspect of the present invention is a non-contact sealing device for a turbomachine, wherein a plurality of disc-shaped seals are provided along a rotation axis of the rotary structure on a surface of the rotary structure in a gap between the rotary structure and the stationary structure of the turbomachine. A convex portion and a concave portion other than the convex portion, and a low seal fin and a high seal fin provided on the stationary structure side facing the convex portion and the concave portion, and the convex portion provided on the rotating structure. A configuration in which a radial gap formed by the low seal fin provided in the stationary structure is set smaller than a radial gap formed by the concave portion of the rotating structure and the high seal fin of the stationary structure. I do.
[0053]
ADVANTAGE OF THE INVENTION According to this invention, the sealing performance at the time of a steady operation is high, the danger of the contact between a rotating structure and a stationary structure at the time of low load accompanying a start / stop is low, and the rotating structure in the event of contact It is possible to provide a non-contact sealing device for a turbomachine with little damage on the side.
[0054]
According to a thirteenth aspect of the present invention, in any one of the tenth to twelfth aspects, a groove which forms an acute angle with respect to the direction of rotation of the rotating structure is provided at the top of the convex portion provided on the rotating structure. Configuration.
According to the present invention, the higher the rotation speed of the turbomachine, the better the sealing performance can be obtained.
[0055]
According to a fourteenth aspect of the present invention, in any one of the tenth to thirteenth aspects, the heat conductivity of the material of the seal fin provided on the stationary structure side is higher than the heat conductivity of the material of the seal portion of the rotating structure. Small configuration.
ADVANTAGE OF THE INVENTION According to this invention, even when a stationary side seal fin and a rotating structure contact, damage of a rotating structure can be suppressed to a small extent.
[0056]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. Taking a steam turbine which is one of turbo machines as an example, among them, a non-contact seal device provided between a rotor and a stationary blade inner ring will be described as an example, but the following description is based on a shroud cover at a tip of a moving blade. The same applies to a sealing device provided between the stator vane outer ring or the casing or a non-contact sealing device provided between the rotor and the casing, which is generally called a gland.
[0057]
First, a first embodiment of the present invention will be described with reference to FIGS.
FIGS. 1A, 1B, 1C and 1D are cross-sectional views showing a staggered labyrinth sealing device which is a non-contact sealing device according to the first embodiment of the present invention. In FIG. 1, reference numeral 9 denotes an inner ring of a stationary blade, 2 denotes a packing ring, 4 denotes a seal fin on a stationary side, 6 denotes a seal fin on a rotary side, and 5 denotes a rotor. (A) shows a cold state before the start of the steam turbine, and (b) shows an unsteady operation state from a no-load state after the start of the steam turbine to an extremely low load at the time of increasing the load. This indicates a long state. (C) shows a steady operation state of the steam turbine, which is a so-called steady state, and (d) shows an extremely low load operation state at the time of rapid warm-up start-up after a short stop of the turbine or no operation immediately after load interruption. This is an unsteady operation state such as during a load operation, and indicates a so-called rotor short state.
[0058]
In the non-contact seal device of the present embodiment, the pitch of the seal fins 4 and 6 of the labyrinth is set to be equal to or smaller than the fluctuation width of the axial thermal expansion difference of the steam turbine, and the fins are densely arranged. ing. Further, at the time of starting and stopping, the radial gap at the tip of the stationary side seal fin 4 is set wide to avoid rubbing, and at the time of high turbine load where high sealing performance is required, the seal fin 4 is pushed out in the inner diameter direction. A clearance control system that improves the sealing performance by setting the radial gap at the tip narrow is applied.
[0059]
After the turbine is started from the cold state in FIG. 1A, the stationary seal fins 4 are not moved until the axial position of the rotating seal fins 6 exceeds the axial position of the stationary seal fins 4 due to thermal expansion of the rotor 5. Is formed so as to have a radial gap between the tip of the seal fin 6 on the rotating side and the tip of the rotating fin 6.
[0060]
Preferably, as shown in FIG. 2, the height of the seal fins 6 on the rotating side is higher than the height of the seal fins 4 on the stationary side. More preferably, the configuration is such that the height of the seal fin 6 on the rotating side is higher than the height of the seal fin 4 on the stationary side by 0.25 mm or more.
[0061]
Preferably, as shown in FIG. 3, the stationary-side seal fins 4 are located upstream of the center of the rotating-side seal fin pitch during a high-load operation of the steam turbine.
[0062]
Preferably, as shown in FIG. 4, when the load of the steam turbine is within the range of 5% to 50% of the rated output (F) in the start-up process of the steam turbine facility, the radial clearance control system is activated. When the operation is completed and the steam turbine load is further increased, the seal fins 4 attached to the stationary structure side are always kept at the minimum radial position (A). More preferably, during the start-up process of the steam turbine facility, the operation of the radial clearance control system is completed when the load on the steam turbine is at about 25% of the rated output.
[0063]
In FIG. 4, A is the radial position of the seal fin to which the clearance control system is applied, B is the relative displacement in the radial direction between the stationary structure (such as the inner ring of the stationary vane) supporting the seal fin and the rotating structure, and C is 2 to 2. 5% load position, D is 5-20% load position, E is the operation amount of the seal fin applied to the clearance control system, F is 5-50% load position, G is the radial gap at the seal tip of the seal fin applied to the clearance control system. , H are the radial positions of the seal fins without the clearance control system.
[0064]
As described above, the non-contact sealing device according to the first embodiment is different from the conventional staggered labyrinth sealing device shown in FIG. 24 and the staggered labyrinth and clearance control method conventionally performed as shown in FIG. It is possible to set the pitch of the seal fins smaller than the seal device by the combination, and the seal fins are densely arranged.
[0065]
Although the sealing performance of the labyrinth seal device is generally improved by increasing the number of rows of the seal fins, in the non-contact seal device of the present embodiment, the pitch of the seal fins 4 and 6 at the time of starting the turbine (rotor long state). The sum of the maximum value of the differential expansion in the axial direction and the maximum value of the differential expansion in the axial direction when the turbine is stopped (rotor short state), that is, a value smaller than the fluctuation range of the differential expansion. Therefore, the axial gap between the rotating side seal fins 6 and the stationary side seal fins 4 becomes negative in at least one of the rotor long state and the rotor short state, causing interference. FIG. 1B shows this state, and if attention is paid only to the positional relationship in the axial direction, during the change from FIG. 1A to FIG. 1B, and reaches an axial position beyond the stationary side seal fin 4 as shown in FIG. 1B. At this time, if there is no significant change in the radial positional relationship between the rotating seal fins 6 and the stationary seal fins 4, these seal fins 4 and 6 come into contact with each other, causing excessive shaft vibration and hindering the operation of the turbine. Will be caused. Further, even if the operation can be continued, the seal fins 4 and 6 that have come into contact with each other can hardly form a stagger in the radial direction due to damage to the seal fins 4 and 6, so that a decrease in sealing performance is inevitable.
[0066]
In this embodiment, the pitch of the seal fins 4 and 6 is set to be small, and the seal fins 4 and 6 are densely arranged. The rubbing is avoided by setting the radial gap at the tip of the seal fin 4 wide. At the time of high turbine load where high sealing performance is required, the packing ring 2 on the stationary side is pushed out in the radial direction by the clearance control to narrow the gap 7 between the tip of the seal fin 4 and the rotor 5 so that the high turbine load is achieved. The sealing performance has been improved.
[0067]
As described above, the non-contact seal device according to the present embodiment is a staggered type labyrinth seal device used for a steam turbine. Can be safely realized without inducing. As a result, the sealing performance of the staggered labyrinth sealing device is improved, which contributes to the performance improvement of the steam turbine.
[0068]
Further, as shown in FIG. 2, by configuring the height of the seal fins 6 on the rotating side to be higher than the height of the seal fins 4 on the stationary side, the seal fins 4 Even if the radial gaps 7 and 10 at the tips become small and the tips of the seal fins make contact with the mating side, the contact is made only between the seal fins 6 on the rotating structure side and the packing or seal fin holder (stationary structure side). (The inner surface of the stator vane inner ring, stator vane outer ring, casing or casing accessory) and not the surface of the rotor 5 shaft or the shroud cover at the tip of the rotor blade. The shroud cover and the shroud cover are not deformed, and the operation of the turbine is not hindered.
[0069]
When the tip of the seal fin 6 on the rotating structure side comes into contact with the stationary structure and frictional heat is generated at the tip of the seal fin 6, the seal fin also functions as a cooling fin. The generated heat is cooled by the cooling effect of the seal fins 6 placed in the high-speed fluid while being transmitted to the roots of the seal fins 6, so that the temperature of the roots of the seal fins 6 does not greatly increase. Therefore, in this case, no significant thermal bending of the rotor 5 and no significant deformation of the shroud cover are caused, and no excessive shaft vibration is generated.
Further, in a staggered labyrinth configured such that the height of the rotating side seal fins 6 is higher than the height of the stationary side seal fins 4, as shown in FIG. By configuring the stationary-side seal fins 4 to be located downstream of the center of the fin pitch of the rotating-side seal fins 6 during the load operation, an improvement in sealing performance can be expected. In such a staggered labyrinth seal device using a combination of labyrinths having different heights of the seal fins, the shafts of the rotating side seal fins 6 having a narrow radial gap and the stationary seal fins 4 having a wide radial gap are provided. The sealing performance changes depending on the relative position in the direction.
[0070]
An example is shown in FIG. In FIG. 5, S is the fin pitch, and a is the axial clearance of the seal fin. Therefore, in this case, such a staggered type labyrinth seal device is configured such that the stationary-side seal fin is located downstream of the center of the rotary-side seal fin pitch during the high-load operation of the turbomachine. Sealing performance can be improved.
[0071]
In the steam turbine, the change in the radial gap mainly occurs during an unsteady operation such as a start-up, a stop, or a large load change at a low load. FIG. 6 shows the amount of change in the radial gap from the start of the turbine to the rated load in a conventional steam turbine not using the clearance control system. In FIG. 6, B, C, D and H have the same meaning as in FIG. 4, and J is the radial gap at the seal tip of the seal fin without the clearance control system.
[0072]
In steam turbines, the amount of radial gap change of the seal fins is generally maximum at turbine loads of 2% to 5%, and generally minimal at turbine loads of 5% to 20%. Also, for example, in a high-pressure part of a steam turbine, the difference in the axial extension becomes maximum in the rotor long state during a low load state at the time of complete cold start, and on the other hand, the difference in the axial extension becomes maximum in the rotor short state. This is a very low load operation state at the time of rapid warm-up after a short stop of the turbine, or a no-load operation immediately after load interruption. Generally, the performance of the steam turbine is emphasized in a high load state where the turbine load is 50% or more of the rated output.
[0073]
Therefore, during the start-up process of the steam turbine equipment, the load exceeds the turbine load at which the amount of change in the radial gap becomes the maximum value, and at least the load exceeds the turbine load at which the maximum difference in elongation occurs in the rotor short state. By reducing the seal fin pitch and improving the sealing performance by configuring the operation of the radial clearance control system to be completed when the load of the steam turbine is in the range of 5% to 50% of the rated output in the state. It is possible to provide a non-contact sealing device that can improve contact and avoid contact in the radial and axial directions.
[0074]
By applying the non-contact seal device of the first embodiment, it is possible to reduce the leakage flow rate of the seal portion without causing rubbing, and high-performance, safe and highly reliable steam turbine equipment. Can be provided.
[0075]
Next, a second embodiment of the present invention will be described with reference to FIGS.
FIG. 7 is a sectional view of a comb labyrinth which is a non-contact sealing device according to a second embodiment of the present invention. In general, the pitch of the seal fins on the stationary side of the comb labyrinth is different from the pitch of the seal fins on the rotating side. A labyrinth in which fins are densely arranged by setting the pitch of the seal fins 6 on the side to the same or substantially the same value, and setting those pitches to be equal to or smaller than the fluctuation width of the thermal expansion difference in the axial direction of the turbomachine. It is.
[0076]
The comb-type labyrinth sealing device of the present embodiment is stationary until the axial position of the rotating seal fins 6 exceeds the axial position of the stationary seal fins 4 due to thermal expansion of the rotor after the turbine is started from the cold state. A radial gap 7 is provided between the tip of the seal fin 4 on the side and the tip of the seal fin 6 on the rotation side. At the start and stop, the radial gaps 7 at the tips of the seal fins 4 and 6 are set wide to avoid rubbing, and at the time of turbine high load requiring high sealing performance, the stationary labyrinth packing ring 2 is moved in the radial direction. A clearance control system that improves the sealing performance by extruding the seal fins 4 and 6 so as to narrow the radial gaps at the tips is applied.
[0077]
Preferably, the height of the rotating side seal fins 6 is at least three times the average gap at the tip of the stationary side sealing fins 4 at the time of turbine high load operation, and the height of the rotating side seal fins 6 is set at the stationary side. Is configured to be lower than the height of the seal fin 4.
[0078]
Preferably, as shown in FIG. 8, the stationary seal fins 4 are located upstream of the center of the fin pitch of the rotating seal fins 6 during a high-load operation of the turbomachine. .
[0079]
Preferably, in the start-up process of the steam turbine facility, when the load on the steam turbine is within the range of 5% to 50% of the rated output, the operation of the radial clearance control system is completed, and the steam is further increased. When a turbine load is applied, the seal fins 4 provided on the stationary structure side are configured to be always kept at the minimum radial position. More preferably, during the start-up process of the steam turbine facility, the operation of the radial clearance control system is completed when the load on the steam turbine is at about 25% of the rated output.
[0080]
As shown in FIG. 7, the pitch of the seal fins 4 and 6 is the maximum value of the axial expansion difference when the turbine is started (rotor long state) and the maximum axial expansion difference when the turbine is stopped (rotor short state). It is set to a value smaller than the sum of the values, that is, the fluctuation range of the elongation difference. Therefore, the axial gap between the rotating side seal fins 6 and the stationary side seal fins 4 becomes negative in at least one of the rotor long state and the rotor short state, causing interference.
[0081]
This state appears in the unsteady operation from the no-load state after the start of the steam turbine to the extremely low load at the time of load increase, and if only attention is paid to the axial positional relationship, the cold state before the start of the steam turbine During the transition from the no-load state after the start of the steam turbine to the unsteady operation from the no-load state to the extremely low load when the load increases, the rotating-side seal fins 6 interfere with the stationary-side seal fins 4, and In the unsteady operation from the no-load state after the start-up to the extremely low load at the time of the load increase, the axial position has reached the stationary seal fin 4.
[0082]
At this time, if there is no significant change in the radial positional relationship between the rotating side seal fins 6 and the stationary side seal fins 4, these seal fins 4 and 6 come into contact with each other, causing excessive shaft vibration and hindering the operation of the turbine. Will come. Further, even if the operation can be continued, the seal fins 4 and 6 that have come into contact with each other can hardly form a stagger in the radial direction due to damage to the seal fins 4 and 6, so that a decrease in sealing performance is inevitable.
[0083]
In this embodiment, the pitch of the seal fins 4 on the stationary side and the pitch of the seal fins 6 on the rotary side are set to the same or almost the same value, and the pitch of the seal fins is set to be small. The fins are densely arranged, and a clearance control is applied to prevent the rubbing by setting the radial gap at the tip of the seal fin wide at the time of starting and stopping. At the time of high load of the turbine that requires high sealing performance, the labyrinth on the stationary side is pushed out in the radial direction by the clearance control to narrow the gap 7 at the seal fin tip, thereby improving the sealing performance at the time of high load of the turbine.
[0084]
As shown in FIG. 9, a sufficient sealing effect can be obtained by setting the height h2 of the rotating-side seal fins 6 to be at least three times the average gap ε1 at the tip of the stationary-side seal fins 4 at the time of high-load operation of the turbine. can get. Therefore, from the viewpoint of sealing performance, it is possible to design the height of the seal fin 6 on the rotating side to be lower than the height of the seal fin 4 on the stationary side within this range, so that the rotor shaft or the shroud cover can be designed. It is preferable to reduce the fin height of the rotating side seal fins 6 which are integrally formed from each other and have difficulty in regeneration in the event of damage, thereby making them rigid.
[0085]
Further, in the labyrinth configured such that the height of the rotating-side seal fins 6 is lower than the height of the stationary-side seal fins 4, as can be seen from FIG. At times, the stationary seal fins 4 are arranged upstream of the center of the fin pitch of the rotary seal fins 6, thereby improving the sealing performance.
[0086]
Also in the present embodiment, in the start-up process of the steam turbine facility, the load difference exceeds the turbine load at which the amount of change in the radial gap of the seal fin becomes the maximum value, and at least the maximum difference in elongation in the rotor short-circuit state is reduced The configuration is such that the operation of the radial clearance control system of the seal fins is completed when the load on the steam turbine is in the range of 5% to 50% of the rated output, where the load condition exceeds the generated turbine load. In addition, it is possible to provide a non-contact seal device capable of improving the sealing performance by reducing the seal fin pitch and avoiding contact in the radial and axial directions.
[0087]
By applying the non-contact seal device of the second embodiment, it is possible to reduce the leakage flow rate of the seal portion without causing the occurrence of rubbing, and high-performance, safe and highly reliable steam turbine equipment. Can be provided.
[0088]
Next, a third embodiment of the present invention will be described. The third embodiment of the present invention relates to a steam turbine facility, in which a rotor from a high-pressure turbine to a low-pressure turbine is integrally formed so as not to be disassembled, and a rotor from a high-pressure portion to a low-pressure portion of the rotor is used. This is a high-low pressure integrated steam turbine facility having a structure in which turbine stages are housed in a single turbine casing, and the turbine stages form a single-flow structure steam passage.
[0089]
The steam turbine equipment of the present embodiment has a rated output of 80 MW or more, the main steam has a steam pressure of 10 MPa or more and a steam temperature of 500 ° C. or more, and the first or second sealing device used as a turbine stage is used as a sealing device. The non-contact sealing device according to the second embodiment is applied. In the non-contact sealing device, the tip of the rotating seal fin and the stationary side are used at the time of starting and stopping of the turbomachine and at the time of extremely low load operation by using a radial clearance control method. The seal fin tip has a gap in the radial direction, and during high load operation, the rotating seal fin tip and the stationary seal fin tip are staggered in the radial direction. When located near the shaft end on the high pressure turbine side, the seal fin pitch on the rotating side or stationary side of the labyrinth of the high pressure stage is Hereinafter discrepancy type labyrinth of 8mm was considered by, preferably a 6mm or less, 14mm labyrinth seal fin pitch of the low-pressure paragraph, preferably a 10mm or less.
[0090]
Here, the stationary side is a term for the rotating side and means the non-rotating side. Further, the seal fin pitch referred to herein means a fin pitch of the seal fins in which the stationary side labyrinth is operated in the radial direction by the clearance control device and the stationary side seal fins are different from the rotating side seal fins. When there is a low seal fin that does not form a stagger between the high seal fins that form a stagger, the fin pitch when the low seal fin is ignored. These terms have the same meaning in the following embodiments.
[0091]
According to the third embodiment, it is possible to reduce the leakage flow rate of the seal portion without causing the occurrence of rubbing in the seal portion of the steam turbine. Equipment can be provided.
[0092]
A fourth embodiment of the present invention relates to a steam turbine facility, which includes a high-pressure turbine, an intermediate-pressure turbine, and a low-pressure turbine, and an intermediate-low-pressure rotor in which the rotors of the intermediate-pressure turbine and the low-pressure turbine are integrally formed so as not to be disassembled. The rotor of the high-pressure turbine manufactured separately from the middle-low pressure rotor is mechanically joined to form one rotor, and the turbine stage of the high-pressure part is stored in the high-pressure turbine casing, The turbine stage has a structure that is housed in a medium- and low-pressure turbine casing separate from the high-pressure turbine casing.The turbine stages form a single-flow structure steam passage, and the thrust bearing is located near the shaft end on the high-pressure turbine side. Steam turbine equipment.
[0093]
The steam turbine equipment of this embodiment has a rated output of 100 MW or more, the main steam has a steam pressure of 10 MPa or more and a steam temperature of 520 ° C. or more, and the first or second seal device used as a turbine stage is used as a seal device. The non-contact sealing device according to the second embodiment is applied. In the non-contact sealing device, the tip of the rotating seal fin and the stationary side are used at the time of starting and stopping of the turbomachine and at the time of extremely low load operation by using a radial clearance control method. The seal fin tip has a gap in the radial direction, and at the time of high load operation, the rotating seal fin tip and the stationary seal fin tip are staggered in the radial direction. The pitch of the seal fins on the rotating side or stationary side of the labyrinth is different from the seal fin pitch of the labyrinth that was considered in the conventional steam turbine. Chiyori hereinafter also small 8 mm, preferably between 6mm or less, and 14mm below the labyrinth seal fin pitch of the low-pressure paragraph, preferably a 10mm or less.
[0094]
According to the fourth embodiment, in the seal portion of the steam turbine, it is possible to reduce the leakage flow rate of the seal portion without causing the occurrence of rubbing. Turbine equipment can be provided.
[0095]
A fifth embodiment of the present invention relates to a steam turbine facility, which includes a high-pressure turbine, an intermediate-pressure turbine, and a low-pressure turbine, and a medium-pressure low-pressure rotor in which the rotors of the medium-pressure turbine and the low-pressure turbine are integrally formed so as not to be disassembled. The rotor of the high-pressure turbine manufactured separately from the middle-low pressure rotor is mechanically joined to form one rotor, and the turbine stage of the high-pressure part is stored in the high-pressure turbine casing, The turbine stage has a structure that is housed in a medium-to-low pressure turbine casing separate from the high-pressure turbine casing, the turbine stages form a steam passage having a single-flow structure, and a thrust bearing is provided between the high-pressure turbine and the medium-pressure turbine. The steam turbine facility is located in
[0096]
The steam turbine equipment of this embodiment has a rated output of 100 MW or more, the main steam has a steam pressure of 10 MPa or more and a steam temperature of 520 ° C. or more, and the first or second seal device used as a turbine stage is used as a seal device. The non-contact sealing device according to the second embodiment is applied. In the non-contact sealing device, the tip of the rotating seal fin and the stationary side are used at the time of starting and stopping of the turbomachine and at the time of extremely low load operation by using a radial clearance control method. The seal fin tip has a gap in the radial direction, and at the time of high load operation, the rotating seal fin tip and the stationary seal fin tip are staggered in the radial direction. The pitch of the seal fins on the rotating side or stationary side of the labyrinth is different from the seal fin pitch of the labyrinth that was considered in the conventional steam turbine. Chiyori hereinafter also small 8 mm, preferably between 6mm or less, and 12mm below the labyrinth seal fin pitch of the low-pressure paragraph, preferably a 9mm or less.
[0097]
According to the fifth embodiment, in the seal portion of the steam turbine, it is possible to reduce the leakage flow rate of the seal portion without causing the occurrence of rubbing. Turbine equipment can be provided.
[0098]
A sixth embodiment of the present invention relates to a steam turbine facility, which includes a high-pressure turbine, an intermediate-pressure turbine, and a low-pressure turbine, and in which the rotors of the high-pressure turbine and the intermediate-pressure turbine are integrally formed so as not to be disassembled. A high-medium pressure rotor and a low-pressure turbine rotor manufactured separately are mechanically joined to form a single rotor, and a high-medium pressure turbine stage is housed in a high-medium pressure turbine casing; Of the turbine stage is housed in a low-pressure turbine casing separate from the high- and medium-pressure turbine casing, the low-pressure turbine stage forms a double-flow structure steam passage, and the thrust bearing is located near the shaft end on the high-pressure turbine side. Steam turbine equipment.
[0099]
The steam turbine equipment according to this embodiment has a rated output of 120 MW or more, the main steam has a steam pressure of 10 MPa or more and a steam temperature of 520 ° C. or more, and the first or second seal device used for a turbine stage. The non-contact sealing device according to the second embodiment is applied. In the non-contact sealing device, the tip of the rotating seal fin and the stationary side are used at the time of starting and stopping of the turbomachine and at the time of extremely low load operation by using a radial clearance control method. The seal fin tip has a gap in the radial direction, and at the time of high load operation, the rotating seal fin tip and the stationary seal fin tip are staggered in the radial direction. The pitch of the seal fins on the rotating side or stationary side of the labyrinth is different from the seal fin pitch of the labyrinth that was considered in the conventional steam turbine. Chiyori hereinafter also small 8 mm, preferably between 6mm or less, and a labyrinth seal fin pitch of the low-pressure paragraphs 16mm or less, preferably set to 12mm or less.
[0100]
According to the sixth embodiment, in the seal portion of the steam turbine, it is possible to reduce the leakage flow rate of the seal portion without causing the occurrence of rubbing. Turbine equipment can be provided.
[0101]
A seventh embodiment of the present invention relates to a steam turbine facility, comprising a high-pressure turbine, an intermediate-pressure turbine, and a low-pressure turbine, wherein a rotor of the high-pressure turbine and a rotor of the intermediate-pressure turbine are integrally formed so as not to be disassembled. The high-medium pressure rotor and the rotor of the low-pressure turbine manufactured separately are mechanically joined to constitute one rotor, and the turbine stage of the high-medium pressure part is stored in the high-medium-pressure turbine casing, The turbine stage has a structure that is housed in a low-pressure turbine casing separate from the high-medium-pressure turbine casing, the low-pressure turbine stage forms a steam passage of a double-flow structure, and a thrust bearing is located between the high-medium-pressure turbine and the low-pressure turbine. Steam turbine equipment.
[0102]
The steam turbine equipment according to this embodiment has a rated output of 120 MW or more, the main steam has a steam pressure of 10 MPa or more and a steam temperature of 520 ° C. or more, and the first or second seal device used for a turbine stage. The non-contact sealing device according to the second embodiment is applied. In the non-contact sealing device, the tip of the rotating seal fin and the stationary side are used at the time of starting and stopping of the turbomachine and at the time of extremely low load operation by using a radial clearance control method. The high-pressure stage labyrinth is configured so that the tip of the seal fin has a radial gap and the tip of the rotating seal fin and the tip of the stationary seal fin form a stagger in the radial direction during high-load operation. The seal fin pitch on the rotating side or stationary side of the seal labyrinth of the staggered labyrinth considered in the conventional steam turbine Small 12mm or less than, preferably a 9mm or less, and 10mm below the labyrinth seal fin pitch of the low-pressure paragraph, preferably not more than 8 mm.
[0103]
According to the seventh embodiment, in the seal portion of the steam turbine, it is possible to reduce the leakage flow rate of the seal portion without causing the occurrence of rubbing. Turbine equipment can be provided.
[0104]
As described above, in the first to seventh embodiments of the present invention, the seal fins are arranged densely by setting the pitch of the seal fins small, and the seal is applied at the time of starting and stopping by applying the clearance control. Rubbing is avoided by setting the radial gap at the fin tip wide. In addition, when the turbine is under high load where high sealing performance is required, the labyrinth on the stationary side is pushed out in the radial direction by the clearance control to narrow the gap at the tip of the seal fin, thereby improving the sealing performance under high turbine load.
[0105]
Therefore, in a labyrinth sealing device having a structure in which the labyrinth on the stationary side and the labyrinth on the rotating side are staggered, an unusual event such as rubbing may be caused by a large increase in the number of rows of seal fins, which was impossible in the past. And can be realized safely without any problem. As a result, the effect of greatly improving the sealing performance of the staggered labyrinth sealing device is exhibited, which greatly contributes to the improvement of the performance of the turbo machine.
[0106]
In addition, by applying the non-contact seal device of the first and second embodiments to a steam turbine, it is possible to reduce the leakage flow rate of the seal portion without causing the occurrence of rubbing. In addition, safe and reliable steam turbine equipment can be provided.
[0107]
Next, an eighth embodiment of the present invention will be described.
10A and 10B are cross-sectional views of the non-contact seal device of the present embodiment, in which FIG. 10A is a diagram in a steady operation state of the steam turbine, and FIG. FIG. 7C is a diagram in an unsteady operation state at a low load at the time, and FIG. 7C is a diagram in an unsteady operation state at a low load when the load of the steam turbine is reduced.
[0108]
The steam turbine according to the present embodiment includes a rotating structure including a turbine shaft 5a and a moving blade provided on turbine shaft 5a, and further includes a stationary blade and a stationary blade inner ring disposed on the inner diameter side of the stationary blade ring. The stationary structure includes a stationary blade outer ring provided on an outer diameter side of the stationary blade ring, a casing covering the outer ring, and a bearing for supporting a rotating structure. A packing ring 2 is held on the inner ring of the stationary blade.
[0109]
In the non-contact sealing device according to the present embodiment, two or more disk-shaped convex portions 66 are formed on the surface of the turbine shaft 5a, which is a rotating structure, and the stationary blade is a stationary structure facing the turbine shaft 5a. The lower seal fins 44 corresponding to the convex portions 66 of the turbine shaft 5a are formed on the inner ring packing ring 2, and the high seal fins 45 corresponding to the concave portions 60 of the turbine shaft 5a are formed between the low seal fins 44. It is. As a gap setting at the time of assembling the turbine, a radial gap 77 formed by the convex portion 66 of the turbine shaft 5a and the low seal fin 44 provided on the packing ring 2 side is set to the concave portion 60 of the turbine shaft 5a and the packing ring 2 side. Is set smaller than the radial gap 78 formed by the high seal fins 45 provided in the first and second fins.
[0110]
Preferably, the radial gap 78 formed by the concave portion 60 of the turbine shaft 5a and the high seal fin 45 provided on the packing ring 2 side is set to a gap equivalent to that of a conventional labyrinth seal, and The radial gap 77 formed by the convex portion 66 of the shaft 5a and the low seal fin 44 provided on the packing ring 2 side is smaller than the gap of the conventional labyrinth seal, and preferably about １ ／ of the conventional gap. You have set.
[0111]
The low seal fins 44 provided on the side of the packing ring 2 are located at substantially the same axial position as the convex portions 66 of the turbine shaft 5a when the turbine load is near the rated load and is operated in a steady load state. And a small gap 77 is formed.
[0112]
The operation of the non-contact sealing device according to the eighth embodiment having the above-described configuration will be described below in comparison with a conventional device. FIG. 11 is a sectional view showing an example of a conventional labyrinth seal called a high-low type, and shows a radial direction formed by a convex portion 66 of the turbine shaft 5a and a low seal fin 44 provided on the packing ring 2 side. The gap 77 is set to be the same as the radial gap 78 formed by the concave portion 60 of the turbine shaft 5a and the high seal fin 45 provided on the packing ring 2 side.
[0113]
As described above, in the labyrinth seal, the biggest factor that determines the effect of preventing steam leakage is that the tip of the seal fins 44 and 45 provided on the packing ring 2 side of the stationary vane inner ring, which is a stationary structure, and the rotating structure The size of the gaps 77 and 78 in the radial direction with respect to the surface of the turbine shaft 5a, which is an object, is smaller. The smaller the gap is, the smaller the amount of steam leakage is and the performance of the turbine is improved. During operation, the turbine shaft 5a comes into contact with the seal fins 44, 45, and the turbine shaft 5a and the seal fins 44, 45 are damaged, the shaft vibration increases due to the contact, and the operation cannot be continued. There is a problem that the heat is generated so that the turbine shaft 5a, which is a rotating structure, is bent.
[0114]
Such contact occurs because the values of the gaps 77 and 78 change depending on the operating state of the turbine, and such changes may be caused by uneven thermal deformation of the casing, deformation by pressure, or damage to the turbine shaft. This is caused by various factors such as the support characteristics of the bearing to be supported, and particularly, the change in the clearance occurs when the turbine starts and stops and when the load changes at a low load due to the start and stop.
[0115]
A curve Y shown by a solid line in FIG. 12 indicates that the steam turbine having a characteristic that an inverted temperature-like casing thermal deformation is caused by the occurrence of an uneven temperature distribution of the casing at the time of start-up. The relative displacement difference in the radial direction (upward in the vertical direction) between the fin and the seal fins provided on the supported stationary vane inner ring is expressed from the start of the steam turbine to the rated load with the origin at the time of turbine assembly. is there. A straight line X indicated by a broken line in FIG. 10 represents a radial gap setting value between the seal fin and the turbine shaft when the turbine is assembled.
[0116]
On the vertical axis of FIG. 12, the value of XY (the value obtained by subtracting the value of Y from the value of X) is the radial gap of the labyrinth seal at the turbine load. At the lowest load. After that, when the turbine load increases, the gap XY once increases and then slightly decreases as the load further increases. However, as the turbine load approaches 100%, the amount of the change decreases and settles to a constant value. It has such a tendency.
[0117]
If the gap value X in the radial direction at the time of turbine assembly is small and the value of the gap XY becomes negative during operation, it means that the seal fins are in contact with the turbine shaft, and excessive shaft vibration is caused. And the turbine shaft bends. In addition, in such a turbine, when the casing is stopped, the casing generally deforms like a cat on the contrary to that at the time of starting, and the gap on the lower side in the vertical direction becomes small, and there is a risk of contact.
[0118]
Further, as described above, the amount of change in the gap is extremely small because the amount of deformation and the amount of change settle to a constant value over time during steady operation. Therefore, in consideration of the gap state at the time of starting and stopping or at the time of load change at a low load, if the radial gap setting value X at the time of turbine assembly is set too large so that rubbing does not occur in any operating state, a long time is required. In a steady state operation over time, the gap becomes unnecessarily large, the amount of steam leakage increases, and good performance as a turbine cannot be obtained.
In order to solve such a problem, in the eighth embodiment, the gap at the time of assembling the turbine is formed by removing the low seal fins 44 provided on the convex portion 66 of the turbine shaft 5a and the packing ring 2 side of the inner ring of the stationary blade. Is set smaller than the radial gap 78 formed by the concave portion 60 of the turbine shaft 5a and the high seal fin 45 provided on the packing ring 2 side of the stationary blade inner ring. . Preferably, the radial gap 78 formed by the concave portion 60 of the turbine shaft 5a and the high seal fin 45 provided on the inner side of the stator vane is set to a gap equivalent to the gap of the conventional labyrinth seal. A radial gap 77 formed by the convex portion 66 of the shaft 5a and the low seal fin 44 provided on the inner side of the stationary blade is set smaller than the gap of the conventional labyrinth seal.
[0119]
By setting the gap at the time of assembling the turbine as described above, there is no contact in the radial gap 78 formed by the concave portion 60 of the turbine shaft 5a and the high seal fin 45 provided on the stationary blade inner ring side. It can be said that. On the other hand, the radial gap 77 formed by the convex portion 66 of the turbine shaft 5a and the low seal fin 44 provided on the inner side of the stationary blade at the time of assembling the turbine is set to be small, and preferably set to about 1/2 of the conventional size. However, in actuality, the convex portion of the turbine shaft 5a is caused by the difference in the thermal elongation between the rotating structure and the stationary structure due to the start / stop of the steam turbine or a change in load due to the change in load. 66 and the lower seal fins 44 provided on the inner side of the stator vane have different positions in the turbine axial direction, so that it is possible to avoid contact.
[0120]
Generally, a steam turbine requires high performance at a high load at which steady-state operation is performed, particularly, high performance at a 100% load. Therefore, in a steady operation state at a high load, it is strongly required to narrow the seal gap. On the other hand, the extremely low load state only passes when starting and stopping, and in this state, particularly high performance is not required.In the extremely low load state, even if the seal gap is wide, there is no particular problem in performance. Absent.
[0121]
That is, FIG. 10A is a cross-sectional view showing a state of the labyrinth seal of the present embodiment in a steady operation state of the steam turbine, and the gap is set so as to avoid contact. At this time, the radial gap 77 formed by the convex portion 66 of the turbine shaft 5a and the low seal fin 44 provided in the packing ring 2 on the inner ring side of the stationary blade is smaller than that of the conventional labyrinth seal, and The volume is smaller than that of the conventional labyrinth seal, which contributes to improving the performance of the turbine.
[0122]
FIG. 10B is a cross-sectional view showing a state of the labyrinth seal of the present embodiment in an unsteady operation state at a low load when the load is increased from an extremely low load after the start of the steam turbine. In b), the radial gap 77 on the upper half side formed by the convex portion 66 of the turbine shaft 5a and the low seal fin 44 provided on the packing ring 2 on the inner ring side of the stationary blade has a negative value and overlaps. In other words, due to the difference in thermal expansion between the rotating structure and the stationary structure, a difference in thermal expansion occurs between the convex portion 66 of the turbine shaft 5a and the low seal fin 44 provided on the packing ring 2 on the inner side of the stationary blade. The contact between the convex portion 66 of the turbine shaft 5a and the low seal fin 44 provided on the packing ring 2 on the inner side of the stationary blade is caused by the shift of the position in the turbine axial direction. It is, does not occur an excessive axial vibration.
[0123]
FIG. 10C is a cross-sectional view showing a state of the labyrinth seal of the present embodiment in an unsteady operation state at a low load when the load of the steam turbine drops, and in FIG. 10C, the convexity of the turbine shaft 5a is shown. The lower half-side radial gap 77 formed by the lower seal fins 44 provided in the packing ring 2 on the inner ring side on the stator blade inner ring side has a negative value and overlaps with each other. The protrusion 66 of the turbine shaft 5a and the low seal fins 44 provided on the packing ring 2 on the inner side of the stationary blade due to the difference in expansion in the direction opposite to that at the time of startup due to the difference in thermal expansion between the stationary structure and the turbine. Since the axial position shifts, contact between the convex portion 66 of the turbine shaft 5a and the low seal fin 44 provided on the packing ring 2 on the inner side of the stationary blade is avoided. , Is not the occurrence of excessive shaft vibration.
[0124]
As described above, by applying the non-contact sealing device of the eighth embodiment, it is possible to improve the sealing performance at the time of steady operation as compared with the conventional one, contributing to the improvement of the performance of the turbine, and at the same time, to start and stop. Accordingly, contact between the turbine shaft 5a and the seal fins 44 and 45 at the time of low load can be avoided, and a highly reliable steam turbine can be provided.
[0125]
Next, a ninth embodiment of the present invention will be described.
13A and 13B are cross-sectional views of the non-contact sealing device of the present embodiment, in which FIG. 13A is a diagram in a steady operation state of the steam turbine, and FIG. FIG. 7C is a diagram in an unsteady operation state at a low load at the time, and FIG. 7C is a diagram at a low load when the load of the steam turbine is reduced.
[0126]
In the non-contact seal device of the present embodiment, high convex portions 66 and low convex portions 67 protruding in a disk shape are formed alternately in the axial direction of the turbine shaft 5a on the surface of the turbine shaft 5a as a rotating structure. The seal ring 2 held on the inner ring of the stationary blade, which is a stationary structure opposed to the turbine shaft 5a, has a low seal fin 44 and a high seal fin 45 corresponding to the high convex portion 66 and the low convex portion 67 of the turbine shaft 5a. Are alternately formed. Preferably, as shown in FIG. 14, the radial gap 77 formed by the high convex portion 66 of the turbine shaft 5a and the low seal fin 44 of the packing ring 2 held by the inner ring of the stator vane is provided with a low gap of the turbine shaft 5. It is set smaller than the radial gap 78 formed by the convex portion 67 and the high sealing fin 45 on the inner side of the stationary blade.
[0127]
As described above, in the non-contact seal device according to the ninth embodiment, in the labyrinth seal used as a shaft sealing device of a steam turbine that is one of turbo machines, the surface of the turbine shaft 5a that is a rotating structure is provided. Disc-shaped protruding portions 66 and low protruding portions 67 are alternately formed in the axial direction of the turbine shaft 5a, and the packing is held on a stationary vane inner ring which is a stationary structure facing the turbine shaft 5a. The ring 2 is configured by alternately forming low seal fins 44 and high seal fins 45 corresponding to the high protrusions 66 and the low protrusions 67 of the turbine shaft 5a.
[0128]
In the present embodiment, the radial gap of the labyrinth seal at the time of turbine assembly can be made smaller than the conventional radial gap, and the radial gap is set to about 1/2 as compared with the conventional one. Is preferred.
[0129]
When such a gap is set, a radial gap 77, formed by the seal fins 44, 45 provided on the convex portions 66, 67 of the turbine shaft 5a and the packing ring 2 held on the stationary vane inner ring, Reference numeral 78 denotes a small gap in a steady operation state in a high load region of the turbine. FIG. 13A is a cross-sectional view showing a state of the labyrinth seal according to the present embodiment in a steady operation state in a high turbine load region. However, the turbine shaft 5a does not contact the seal fins 44 and 45, and the gap is small. 77 and 78 are extremely small values. Accordingly, the amount of leaked steam is smaller than that of the conventional labyrinth seal, which greatly contributes to the improvement of the performance of the turbine.
[0130]
Also, when starting the turbine, which causes a remarkable inverted cattle-shaped deformation in the casing, or when stopping the turbine, which causes the cattle-shaped deformation, the deformation of the casing, etc., becomes larger than the labyrinth clearance in the turbine steady operation state. However, in actuality, the convex portion 66 of the turbine shaft 5a is caused by a difference in thermal expansion between the rotating structure and the stationary structure (difference in expansion) due to the start / stop of the steam turbine or a change in load. , 67 and the seal fins 44, 45 provided on the inner side of the stationary blade are different from each other in the turbine axial direction, so that the state shown in FIG. , 67 and the seal fins 44, 45 on the stator blade inner ring side overlap in the radial direction, but the protrusions 66, 67 of the turbine shaft 5a and the stator blade inner ring side seal member. Since the axial position of luffin 44 and 45 varies by a change in the differential expansion, and has a structure capable of avoiding contact. Therefore, even in such a case, there is no contact, and excessive shaft vibration does not occur.
[0131]
FIG. 13C is a cross-sectional view showing a state of the labyrinth seal according to the present embodiment in an unsteady operation state at a low load when the load of the steam turbine is reduced. The lower half radial gap 77 formed by the portion 66 and the lower seal fins 44 provided on the inner side of the stationary blade has a negative value and overlaps. However, a difference in thermal expansion between the rotating structure and the stationary structure causes a difference in elongation in the opposite direction to that at the time of startup, so that the protrusions 66 and 67 of the turbine shaft 5a and the seal fins 44 provided on the stationary blade inner ring side. , 45 are shifted from the position in the turbine axial direction, so that contact is also avoided, and excessive shaft vibration and the like do not occur.
[0132]
As described above, by applying the non-contact sealing device of the ninth embodiment of the present invention, it is possible to improve the sealing performance at the time of steady operation as compared with the conventional one, thereby contributing to the improvement of the performance of the turbine, and at the same time, starting up. It is possible to avoid contact between the turbine shaft 5a and the seal fins 44 and 45 at the time of a low load due to the stop, and to provide a highly reliable steam turbine.
[0133]
In the present embodiment, preferably, as shown in FIG. 14, a radial gap 77 formed by the high convex portion 66 of the turbine shaft 5a and the low seal fin 44 on the inner side of the stator vane is formed with the low convex portion of the turbine shaft 5a. Although the radial gap 78 is set to be smaller than the radial gap 78 formed by the high seal fin 45 on the side of the inner ring of the stator vane, the recess 61 of the turbine shaft 5a and the high seal in the unsteady state are set by setting such a radial gap. Since the danger of contact with the fins 45 is further reduced, a safe and reliable non-contact sealing device is provided.
[0134]
Next, a tenth embodiment of the present invention will be described. In the non-contact sealing device of this embodiment, as shown in FIGS. 15 and 16, at least one groove 30 is formed at the top of the projection 6a of the turbine shaft 5a, which is a rotating structure, at an acute angle to the direction of rotation. It is characterized by doing.
[0135]
FIGS. 15A and 15B are cross-sectional views showing a labyrinth seal portion in the present embodiment as a shaft sealing device. FIG. 16 is a view showing a part of the turbine shaft surface of the labyrinth seal portion according to the present embodiment viewed from the direction indicated by the arrow XVI in FIGS. 15A and 15B. It shows that at least one groove 30 is formed at the top of the convex portion 6a of the turbine shaft 5a at an acute angle to the direction of rotation. The flow Vg of steam in the groove 30 formed on the top of the convex portion 6a of the shaft 5a is shown.
[0136]
In the non-contact sealing device of this embodiment, as shown in FIG. 16, a steam flow Vg flowing inside a groove 30 formed at the top of the convex portion 6a of the turbine shaft 5a at an acute angle to the direction of rotation is formed. Since the gas flows at a large angle with respect to the flow Vr of the leaked steam, the flow Vr of the leaked steam is disturbed, and there is an effect that the amount of the leaked steam is reduced and the sealing performance is improved.
[0137]
Next, an eleventh embodiment of the present invention will be described. In the non-contact sealing device of this embodiment, as shown in FIGS. 17A and 17B, the projecting height of the low convex portion 67 formed on the surface of the turbine shaft 5a, which is a rotating structure, is set to approximately 0.1. 5 mm or more and 2 mm or less. Further, the width W of the top of the high convex portion 66 and the low convex portion 67 is set to 6 mm or less.
[0138]
In the non-contact seal device of this embodiment, as a material of the seal fins 44 and 45 formed on the stationary blade inner ring side which is a stationary structure, the heat conductivity thereof is the same as that of the seal portion of the turbine shaft 5a which is a rotary structure. Use a material that is smaller than the thermal conductivity of the material.
[0139]
Alternatively, in the non-contact sealing device of the present embodiment, the cross-sectional shape of the tops of the projections 66, 67 formed on the surface of the turbine shaft 5a, which is a rotating structure, is changed according to FIGS. 18 (a), (b), (c). Yamagata as shown in
Further, as shown in FIG. 19, a modification of the non-contact sealing device of the present embodiment is formed on a stationary structure corresponding to a high convex portion 66 formed on the surface of a turbine shaft 5a which is a rotating structure. The number of the low seal fins 44 is two or more for one high protrusion 66.
[0140]
Further, the low seal fins 44 formed on the stationary structure corresponding to the high protrusions 66 formed on the surface of the turbine shaft 5a, which is a rotating structure, in the present embodiment, are formed by one step of the high protrusions 66. As a modified example of the non-contact seal device having two or more seal fins, two or more low seal fins 44 formed on one high protrusion 66 of the turbine shaft 5a, and the protrusion of the seal fins 44 The first seal fin and the center or last seal fin may be slightly different in height. FIG. 20 shows three low seal fins 44 formed with respect to one high convex portion 66. The protrusion height of the seal fins 44 is slightly different between the first seal fin and the central seal fin. A configuration having a volume difference 80 is shown.
[0141]
In addition, there are two or more low seal fins 44 formed on the above-mentioned one high convex portion 66, and the protruding height of the low seal fins 44 is different from that of the first seal fin and the center of the first seal fin. In a non-contact sealing device having a slight difference 80 from the seal fin, the difference 80 between the first first seal fin and the center or last seal fin in the projecting height of the low seal fin 44 is approximately. It is preferable that it is 0.5 mm or more and 2 mm or less.
[0142]
The amount of reverse cattle deformation or cattle deformation of the casing caused by the start / stop of the steam turbine is often about 0.3 mm to 1 mm, and therefore, the rotating structure and the stationary structure during the unsteady operation accompanying the start / stop In order to avoid contact with the object, the protruding height of the low convex portion 67 formed on the surface of the turbine shaft 5a, which is a rotating structure, should be approximately 0.5 mm or more and 2 mm or less depending on the amount of deformation of the casing. Preferably, it is thereby possible to reduce the amount of leaked steam during steady operation, and to avoid a contact failure during unsteady operation due to starting and stopping.
[0143]
In addition, the variation width of the difference in elongation between the turbine shaft and the casing caused by the thermal expansion of the components of the steam turbine may be approximately 10 mm to 20 mm in the high pressure and medium pressure portions of the steam turbine where high sealing performance is required. Therefore, in order to minimize the contact between the projections 66, 67 formed on the surface of the turbine shaft 5a and the seal fins 44, 45 due to thermal deformation of the casing in an unsteady state, the surface of the turbine shaft 5 is formed. It is preferable that the width W (FIGS. 17A and 17B) of the tops of the protrusions 66 and 67 be 6 mm or less. By setting the width W of the tops of the projections 66 and 67 to 6 mm or less in this way, the amount of leaked steam during steady operation is reduced, and the contact failure during unsteady operation due to starting and stopping is avoided. Can be.
[0144]
Further, as a material of the seal fins 44 and 45 formed on the stationary blade inner ring 9 side which is a stationary structure, the heat conductivity is smaller than that of a material of a seal portion of the turbine shaft 5a which is a rotary structure. By using a material, even in the unlikely event that a contact occurs, a large amount of frictional heat generated by the contact is quickly diffused by the turbine shaft 5a made of a material having a high thermal conductivity and becomes high temperature. Can reduce the degree of damage to the contact portion of the turbine shaft 5a, whereas the seal fins 44, 45 made of a material having low thermal conductivity cause a large amount of frictional heat to diffuse so slowly that the contact between the seal fins 44, 45 occurs. Since the temperature of the part becomes high and the strength is reduced and the part is rapidly deformed, the damage to the turbine shaft 5a which is a rotating structure can be reduced. .
[0145]
Also, the cross-sectional shape of the tops of the protrusions 66 and 67 formed on the surface of the turbine shaft 5a, which is a rotating structure, is made to be a mountain shape as shown in FIGS. 18 (a), (b) and (c). Even if the gap between the projections 66, 67 formed on the surface of the turbine shaft 5a and the seal fins 44, 45 is further reduced, the projections 66, 67 formed on the surface of the turbine shaft 5a and the seal fin during operation are reduced. Since it is possible to avoid the contact with the seals 44 and 45, it is possible to provide a safe and highly reliable sealing device which can contribute to the improvement of turbine performance with a small amount of leaked steam and can avoid the contact.
[0146]
Further, as a modified example, the low seal fins 44 formed on the stationary structure corresponding to the high protrusions 66 formed on the surface of the turbine shaft 5a which is a rotating structure are attached to one of the high protrusions 66. By using two or more sheets, at least one of the low seal fins 44 has a narrow gap with respect to the high convex portion 66 of the turbine shaft 5a even in a state where a difference in elongation is large such as during a low load operation or an unsteady operation. It is possible to secure a relatively high sealing performance not only at the time of steady operation at a high load but also at the time of low load operation and unsteady operation, and the turbine performance at a partial load is improved. It can also contribute to improvement.
[0147]
Further, as for the low seal fins 44 formed on two or more high protrusions 66 of the turbine shaft 5a, as shown in FIG. By providing a slight difference between the seal fin and the center or last seal fin, as illustrated in the partial cross-sectional view of the seal device in the unsteady operation state at the time of low load after the start shown in FIG. Even in a state where the difference in elongation is large such as during a low-load operation or an unsteady operation, at least one of the low seal fins 44 can form a narrow gap with the high protrusion 66 of the turbine shaft 5a. Thus, a relatively high sealing performance can be ensured even during a low load operation or an unsteady operation, which can contribute to an improvement in turbine performance under a partial load. In addition, at the time of steady operation under a high load, the gap between the low seal fin 44 and the high protrusion 66 of the turbine shaft 5a can be made narrower than before, so that in a steady operation state under a high load. This greatly reduces the amount of steam leaking from the steam turbine, greatly contributing to the improvement of the performance of the steam turbine.
[0148]
In consideration of the amount of thermal deformation of the casing, two or more low seal fins 44 are formed with respect to the one high protrusion 66 described above, and the low seal fins 44 have an initial projection height. In a seal device having a slight difference between the first seal fin and the center seal fin, the first seal fin having the lower projecting height of the seal fin 44 and the center or last seal fin have a smaller height. It is preferable that the difference from the fin is approximately 0.5 mm or more and 2 mm or less.
[0149]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, the sealing performance at the time of a steady operation is high, the danger of the contact between a rotating structure and a stationary structure at the time of low load accompanying a start / stop is low, and the rotating structure in the event of contact It is possible to provide a non-contact seal device for a turbomachine with less damage generated on the side and a steam turbine facility provided with the non-contact seal device.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating a non-contact sealing device for a turbo machine according to a first embodiment of the present invention, wherein (a) is a cold state before the turbo machine is started, and (b) is a state after the turbo machine is started. Unsteady operation state from no load state to extremely low load at the time of load increase (rotor long state), (c) steady operation state of turbomachine (steady state), (d) after short-time stop of turbomachine FIG. 6 is a diagram showing an unusual operation state (rotor short state) such as an extremely low load operation state at the time of rapid warm-up startup or a no-load operation immediately after load interruption.
FIG. 2 is a non-contact sealing device for a turbomachine according to a first embodiment of the present invention, wherein the height of a rotating side seal fin is higher than the height of a stationary side seal fin; FIG.
FIG. 3 is a non-contact seal device for a turbomachine according to a first embodiment of the present invention, in which a stationary seal fin is positioned upstream of a center of a rotary seal fin pitch during a high-load operation of the turbomachine. The figure which shows the modification which is comprised so that it may perform.
FIG. 4 is a curve diagram illustrating an operation of a clearance control system provided in the non-contact sealing device of the turbo machine according to the first embodiment of the present invention.
FIG. 5 shows that the sealing performance changes depending on the axial relative positions of the rotating seal fin having a narrow radial gap and the stationary seal fin having a wide radial gap, and the first embodiment of the present invention. FIG. 3 is a curve diagram illustrating an effect of the embodiment.
FIG. 6 is a curve showing a change in a radial gap from a turbine startup to a rated load in a conventional non-contact sealing device not using a clearance cotton roll system, and illustrating an effect of the first embodiment of the present invention. FIG.
FIG. 7 is a sectional view showing a non-contact sealing device for a turbo machine according to a second embodiment of the present invention.
FIG. 8 is a non-contact seal device for a turbomachine according to a second embodiment of the present invention, in which a stationary seal fin is located upstream of a center of a rotary seal fin pitch during a high load operation of the turbomachine. The figure which shows the modification which is comprised so that it may perform.
FIG. 9 shows that a sufficient sealing effect can be obtained by setting the height of the rotating-side seal fins to be at least three times the average gap at the tip of the stationary-side seal fin during high-load operation of the turbine. FIG. 14 is a curve diagram illustrating the effect of the second embodiment.
FIGS. 10A and 10B are cross-sectional views illustrating a non-contact sealing device for a turbo machine according to an eighth embodiment of the present invention, wherein FIG. 10A illustrates a steady operation state of the turbo machine, and FIG. FIG. 3C is a diagram illustrating an unsteady operation state at a low load when the load is increased from a low load, and FIG.
FIG. 11 is a sectional view illustrating an operation of a non-contact sealing device for a turbo machine according to an eighth embodiment of the present invention.
FIG. 12 is a curve diagram illustrating the operation of a non-contact sealing device for a turbo machine according to an eighth embodiment of the present invention.
13A and 13B are cross-sectional views illustrating a non-contact sealing device for a turbomachine according to a ninth embodiment of the present invention, wherein FIG. 13A is a steady operation state of the turbomachine, and FIG. FIG. 3C is a diagram illustrating an unsteady operation state at a low load when the load is increased from a low load, and FIG.
FIG. 14 is a view showing a modification of the non-contact sealing device for the turbo machine according to the ninth embodiment of the present invention, showing a steady operation state.
FIGS. 15A and 15B are cross-sectional views illustrating a non-contact sealing device for a turbomachine according to a tenth embodiment of the present invention, wherein FIGS.
FIG. 16 is a plan view of the turbo machine according to the tenth embodiment of the present invention when viewed from the direction of the arrow XVI in FIG.
FIGS. 17A and 17B are cross-sectional views illustrating a non-contact sealing device for a turbomachine according to an eleventh embodiment of the present invention, wherein FIGS.
FIG. 18 is a cross-sectional view showing a non-contact sealing device for a turbo machine according to an eleventh embodiment of the present invention, in which (a), (b) and (c) show main parts of different modifications.
FIG. 19 is a sectional view showing still another modification of the non-contact seal device for the turbo machine according to the eleventh embodiment of the present invention.
FIG. 20 is a sectional view showing still another modification of the non-contact sealing device for the turbo machine according to the eleventh embodiment of the present invention.
FIG. 21 is a diagram illustrating an operation of a non-contact sealing device for a turbo machine according to an eleventh embodiment of the present invention and illustrating an unsteady operating state at a low load after startup.
FIG. 22 is a cross-sectional view showing a non-contact sealing device in a turbine shaft portion of a conventional turbomachine, wherein (a), (b), (c), and (d) show different examples.
FIG. 23 is a cross-sectional view showing a non-contact sealing device in a wing portion of a conventional turbomachine, where (a), (b), (c), and (d) show different examples.
FIG. 24 is a cross-sectional view showing a conventional staggered labyrinth seal device that has been used for sealing a gap between a stator blade inner ring and a rotor.
FIG. 25 shows a conventional staggered labyrinth sealing device used for sealing a gap between a moving blade tip and a stationary blade outer ring or a casing, wherein (a) and (b) are cross sections showing different examples, respectively. FIG.
FIG. 26 is a cross-sectional view of a conventional composite direct labyrinth sealing device called a comb labyrinth.
FIGS. 27A and 27B show a conventional staggered labyrinth seal device to which a clearance control system is applied, wherein FIG. 27A shows a start / stop state, and FIG.
FIG. 28 shows a positional relationship between a stationary labyrinth and a rotating labyrinth of a conventional staggered labyrinth seal device accompanying a change in turbine operation state, (a) showing a cold state before starting, (b) showing a starting operation state, FIG. 3C is a diagram illustrating a steady operation state, and FIG.
[Explanation of symbols]
Reference numeral 2: packing ring, 3: leakage steam, 4: seal fin, 5: rotor, 5a: turbine shaft, 6: seal fin, 6a: convex portion, 7: radial gap, 8: stationary blade ring, 9: stationary blade Inner ring, 10: radial gap, 11: elastic body, 12: stationary blade, 14: moving blade, 15: labyrinth seal, 16: moving blade tip, 17: stationary blade outer ring, 18: radial gap, 19: seal fin , 20 ... labyrinth seal, 21 ... shroud cover, 23 ... radial gap, 24 ... seal fin, 30 ... groove, 44 ... low seal fin, 45 ... high seal fin, 60, 61 ... concave part, 66 ... high convex part, 67: low projection, 77, 78: gap, 80: difference.

Claims (14)

In the gap between the rotating structure and the stationary structure of the turbomachine, the axial pitch provided in the rotating structure and the stationary structure is set to be equal to or less than the fluctuation width of the axial thermal expansion difference of the turbomachine. When the turbomachine is started or stopped, the leading end of the rotating seal fin and the leading end of the stationary sealing fin have a gap in the radial direction when the turbomachine starts or stops, and the leading end of the rotating sealing fin and the stationary A non-contact seal device for a turbomachine, comprising: a radial clearance control system that moves the stationary seal fin in a radial direction such that a tip of the seal fin is staggered in a radial direction. The rotating seal fin and the stationary seal fin form a staggered labyrinth, and the height of the rotating seal fin is configured to be higher than the height of the stationary seal fin. The non-contact sealing device for a turbomachine according to claim 1. The stationary-side seal fins and the rotary-side seal fins form a comb-shaped labyrinth having the same or substantially the same axial pitch, and the height of the rotary-side seal fins is an average of the tip of the stationary-side seal fins during high-load operation of the turbine. 2. The turbomachine according to claim 1, wherein the gap is at least three times as large as the gap, and the height of the rotating-side seal fin is lower than the height of the stationary-side seal fin. 3. Non-contact sealing device. The non-contact turbomachine according to claim 2 or 3, wherein the stationary seal fin is located upstream of the center of the rotary seal fin pitch during a high load operation of the turbomachine. Sealing device. It has a rated output of 80 MW or more, the main steam has a steam pressure of 10 MPa or more and a steam temperature of 500 ° C. or more, and the rotor from the high-pressure turbine to the low-pressure turbine is integrally formed so that it cannot be disassembled. Or a high-low pressure rotor in which a rotor of a high-pressure turbine or a high-medium-pressure turbine and a rotor of a low-pressure turbine manufactured separately from each other are mechanically joined to form a single high-low pressure rotor. The turbine stage according to any one of claims 1 to 5, wherein the turbine stages are housed in a single turbine casing, and the turbine stages form a steam passage having a single flow structure. A mechanical non-contact sealing device, and a radial clearance control system provided in the non-contact sealing device. At the time of starting and stopping the machine, and at the time of extremely low load operation, there is a gap in the radial direction between the tip of the rotating seal fin and the tip of the stationary seal fin, and at the time of high load operation, the tip of the rotating seal fin and the stationary seal fin. When the thrust bearing is located near the shaft end on the high pressure turbine side, the seal fin pitch on the rotating side or stationary side of the labyrinth of the high pressure stage is controlled to 8 mm or less when the thrust bearing is positioned near the shaft end on the high pressure turbine side. Steam turbine equipment characterized in that the labyrinth seal fin pitch of the low-pressure stage is 14 mm or less. It has a rated output of 100 MW or more, the main steam has a steam pressure of 10 MPa or more and a steam temperature of 520 ° C. or more, has a high-pressure turbine, a medium-pressure turbine, and a low-pressure turbine. It consists of a medium-to-low pressure rotor integrally formed inseparably, or a medium-to-low pressure rotor made by mechanically joining a rotor of a medium-pressure turbine and a rotor of a low-pressure turbine manufactured separately from each other. The rotor of the high-pressure turbine manufactured separately from the middle-low pressure rotor is mechanically joined to the middle-low pressure rotor to form one rotor, and the turbine stage of the high-pressure portion is stored in the high-pressure turbine casing. The turbine stage of the low pressure section is housed in a medium / low pressure turbine casing separate from the high pressure turbine casing, and the turbine stages form a steam passage having a single flow structure. In a turbine facility, the turbine stage is provided with a non-contact sealing device for a turbomachine according to any one of claims 1 to 5, and a radial clearance control system provided in the non-contact sealing device is used to start and stop the turbomachine and At the time of extremely low load operation, there is a gap in the radial direction between the tip of the rotating side seal fin and the tip of the stationary side seal fin, and at the time of high load operation, the tip of the rotating side seal fin and the distal end of the stationary side seal fin extend in the radial direction. When the thrust bearing is positioned near the shaft end on the high-pressure turbine side, the rotational fin or latitudinal seal fin pitch of the labyrinth of the high-pressure stage is controlled to 8 mm or less, and the labyrinth of the low-pressure stage is controlled when the thrust bearing is located near the shaft end on the high-pressure turbine side. Steam turbine equipment wherein the seal fin pitch is set to 14 mm or less. It has a rated output of 100 MW or more, the main steam has a steam pressure of 10 MPa or more and a steam temperature of 520 ° C. or more, has a high-pressure turbine, a medium-pressure turbine, and a low-pressure turbine. It consists of a medium-to-low pressure rotor integrally formed inseparably, or a medium-to-low pressure rotor made by mechanically joining a rotor of a medium-pressure turbine and a rotor of a low-pressure turbine manufactured separately from each other. The rotor of the high-pressure turbine manufactured separately from the middle-low pressure rotor is mechanically joined to the middle-low pressure rotor to form one rotor, and the turbine stage of the high-pressure portion is stored in the high-pressure turbine casing. The turbine stage of the low pressure section is housed in a medium / low pressure turbine casing separate from the high pressure turbine casing, and the turbine stages form a steam passage having a single flow structure. In a turbine facility, the turbine stage is provided with a non-contact sealing device for a turbomachine according to any one of claims 1 to 5, and a radial clearance control system provided in the non-contact sealing device is used to start and stop the turbomachine and At the time of extremely low load operation, there is a gap in the radial direction between the tip of the rotating side seal fin and the tip of the stationary side seal fin, and at the time of high load operation, the tip of the rotating side seal fin and the distal end of the stationary side seal fin extend in the radial direction. Control to form a stagger, when the thrust bearing is located between the high-pressure turbine and the medium-pressure turbine, the rotating fin or stationary side seal fin pitch of the labyrinth of the high-pressure stage and the medium-pressure stage is 8 mm or less, And the pitch of the seal fins of the labyrinth in the low-pressure paragraph is 12 mm or less. Emissions equipment. It has a rated output of 120 MW or more, the main steam has a steam pressure of 10 MPa or more and a steam temperature of 520 ° C. or more, has a high-pressure turbine, a medium-pressure turbine, and a low-pressure turbine. Consisting of a high-to-medium pressure rotor integrally formed so as not to be disassembled, a low-pressure turbine rotor manufactured separately from this high-to-medium pressure rotor is mechanically joined to the high-to-medium pressure rotor to constitute one rotor, The high-medium pressure turbine section is stored in the high-medium pressure turbine casing, the low-pressure section turbine section is stored in the low-pressure turbine casing separate from the high-medium pressure turbine casing, and the low-pressure turbine section forms a steam passage having a double flow structure. In a turbine facility, a turbine stage is provided with a non-contact seal device for a turbomachine according to any one of claims 1 to 5, wherein the non-contact seal is provided. The radial clearance control system provided at the position has a gap in the radial direction between the tip of the rotating side seal fin and the tip of the stationary side seal fin at the start and stop of the turbomachine and at the time of extremely low load operation and at the time of high load operation. The tip of the rotating-side seal fin and the tip of the stationary-side seal fin are controlled so as to form a stagger in the radial direction, and when the thrust bearing is located near the shaft end on the high-pressure turbine side, the rotating side of the labyrinth of the high-pressure stage Alternatively, the steam turbine equipment is characterized in that the seal fin pitch on the stationary side is 8 mm or less, and the seal fin pitch of the labyrinth of the low-pressure stage stored in the first low-pressure turbine casing close to the thrust bearing is 16 mm or less. It has a rated output of 120 MW or more, the main steam has a steam pressure of 10 MPa or more and a steam temperature of 520 ° C. or more, has a high-pressure turbine, a medium-pressure turbine, and a low-pressure turbine. Consisting of a high-to-medium pressure rotor integrally formed so as not to be disassembled, a low-pressure turbine rotor manufactured separately from this high-to-medium pressure rotor is mechanically joined to the high-to-medium pressure rotor to constitute one rotor, The high-medium pressure turbine section is stored in the high-medium pressure turbine casing, the low-pressure section turbine section is stored in the low-pressure turbine casing separate from the high-medium pressure turbine casing, and the low-pressure turbine section forms a steam passage having a double flow structure. In a turbine facility, a turbine stage is provided with a non-contact seal device for a turbomachine according to any one of claims 1 to 5, wherein the non-contact seal is provided. When the turbomachine is started and stopped and at extremely low load operation, the tip of the rotating seal fin and the tip of the stationary seal fin have a gap in the radial direction when the turbomachine starts and stops at a very low load, and at the time of high load operation, The control is performed so that the tip of the rotating side seal fin and the tip of the stationary side seal fin form a stagger in the radial direction. Steam turbine equipment characterized in that the seal fin pitch of the side or stationary side is 12 mm or less, and the seal fin pitch of the labyrinth of the low pressure stage stored in the first low pressure turbine casing close to the thrust bearing is 10 mm or less. . In the gap between the rotating structure and the stationary structure of the turbomachine, a disk-shaped high and low projections alternately provided on the surface of the rotation structure along the rotation axis of the rotation structure, and the high projection and A non-contact sealing device for a turbomachine, comprising: a low seal fin and a high seal fin provided on a stationary structure side facing a low convex portion. The radial gap formed by the high protrusion provided on the rotating structure and the low seal fin provided on the stationary structure is reduced by the low protrusion provided on the rotating structure and the high seal fin provided on the stationary structure. The non-contact sealing device for a turbomachine according to claim 10, wherein the gap is set smaller than a radial gap formed by the seal. In the gap between the rotating structure and the stationary structure of the turbomachine, a plurality of disc-shaped convex portions and concave portions other than the convex portions provided on the surface of the rotary structure along the rotation axis of the rotary structure, and the convex portion and A low seal fin and a high seal fin provided on the stationary structure side facing the concave portion, and a radius formed by the convex portion provided on the rotating structure and the low seal fin provided on the stationary structure A non-contact sealing device for a turbomachine, wherein a directional gap is set to be smaller than a radial gap formed by the concave portion of the rotating structure and the high sealing fin of the stationary structure. 13. The turbomachine according to claim 10, wherein a groove that forms an acute angle with respect to the direction of rotation of the rotating structure is provided at a top of the projection provided on the rotating structure. Non-contact sealing device. 14. The turbomachine according to claim 10, wherein a thermal conductivity of a material of a seal fin provided on a stationary structure side is smaller than a thermal conductivity of a material of a seal portion of the rotating structure. Non-contact sealing device.

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