JP2013024222A - Sealing device and gas turbine including the sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable sealing device which uses a seal plate placed for suppressing a leak from a space between adjacent member and improves sealing performance in addition to being matched to an offset of a segment member.SOLUTION: In the sealing device for a gas turbine, a seal plate 50 has two plates 51a, 51b of a rectangular cross-section placed spaced apart from each other, and both the plates are connected by a flat spring 52 as an elastic body. Further, curved elastic bodies 53a, 53b extend from the two plates 51a, 51b, with ends 57a, 57b thereof oriented toward inside the seal plate 50 and with one plate end surfaces thereof both made longer by a length equivalent to δg, and side end plates 55a, 55b made of elastic material are connected thereto while a space of δg is maintained.

Description

  The present invention relates to a sealing device and a gas turbine including the sealing device, and in particular, suppresses leakage of cooling air from cooling blades of gas turbine equipment that obtains rotational power by the energy of combustion gas obtained by burning compressed air together with fuel. The present invention relates to a sealing device suitable for the purpose.

  In gas turbines, the working gas is heated to increase the heat efficiency. In particular, the inside of the blade is cooled so that the turbine stationary and moving blades arranged in the working gas can withstand high temperatures. Supplying media. This type of gas turbine, which is generally adopted, is an open cooling method by air cooling. That is, the air extracted from the compressor is used as cooling air, and this air is guided to the inside of the blades through the casing and the inside of the turbine for cooling. And the air after cooling the inside of a blade | wing is discharged | emitted in a gas path from the film cooling hole provided in the blade outer surface, the trailing edge cooling hole, etc. of the blade. Further, a part of the cooling air introduced for cooling the stationary blades is branched as the sealing air for the turbine wheel space, and this air is also discharged to the gas path for suppressing mainstream gas ingress.

  By the way, although the moving blade shroud and the stationary blade body are annularly arranged in the circumferential direction as a segment structure, a gap is provided between the segments in the circumferential direction in consideration of the thermal expansion of the segment member. This gap is designed so that the segment members do not contact each other even at the rated point from the viewpoint of preventing the occurrence of thermal stress. That is, the casing inner outer end side cavity and the gas path introduced as cooling air for the stationary blades communicate with each other in the radial direction through the gap. That is, a part of the cooling air leaks into the gas path through the gap between the segments. This is a so-called leak. Similarly, the diaphragm of the stationary blade is also formed in an annular shape as a segment, but a part of the sealing air leaks. These leaks are losses in themselves and are mixed into the working gas in the gas path, so the temperature of the working gas decreases due to dilution of the relatively low temperature leakage air, and mixing loss causes a decrease in turbine output. Therefore, there is a possibility that the merit of high temperature cannot be fully exhibited.

  As a measure to improve this, generally, a method is adopted in which a seal groove is formed on both sides of the circumferentially adjacent segment and a flat seal plate is installed between the seal grooves to suppress leaked air. ing. However, this type of seal plate cannot cope with a radial shift (referred to as an offset) of the seal groove caused by a deviation in thermal expansion in the radial direction of the segment due to a recent increase in temperature. For this reason, a seal plate has been developed in which a contact portion with a seal groove of a flat seal plate is formed in an arc shape and the center is thinly processed. A typical example is a dog bone type seal plate, and the outer end of the seal plate is formed in an elliptical shape (see, for example, Patent Document 1). As a result, even if the seal groove is offset due to the radial thermal expansion deviation of the segment, a contact point can always be secured on the groove surface, and the central part of the plate is thinned. There is no interference with the part. Furthermore, improvements such as a plurality of line contact lines (see, for example, Patent Document 2) are shown by a seal plate that uses an elastic plate-like member and a plurality of linear protrusions.

US Patent 5158430 JP-A-10-002203

  For example, in a gas turbine facility, providing a sealing device in a cooling air supply path or the like is an effective means for reducing the leakage flow rate. That is, the seal plate mounted between the segments, which is a part of it, suppresses cooling and leakage of sealing air between the gaps for the purpose of development. However, as a result of making the plate shape correspond to the offset, which is the deviation of thermal expansion in the radial direction with increasing temperature, by the trade-off design, in the dog bone type seal plate, the contact state of the seal plate in the seal groove is the conventional surface. From contact to single line contact, naturally, an increase in the leak flow rate is expected as compared to the flat seal plate. In addition, a seal plate composed of a plate-like member and a plurality of linear protrusions to alleviate this problem has an advantage that the surface pressure of the linear protrusions partially increases due to the occurrence of offset. As a result of the formation of a linear protrusion that opens the line contact with the linear protrusion point as a fulcrum, the effect of suppressing leakage may be reduced. As described above, the development of the seal plate includes conflicting problems of reducing the leak flow rate and dealing with the thermal elongation deviation.

  On the other hand, these seal plates are rarely used alone, and are arranged so as to surround the region with a plurality of seal plates so as to block the high-pressure side region and the low-pressure side region that cause leakage. Is done. At this time, it is necessary to form a seal surface between the seal plate and the adjacent seal plate orthogonal to the end surface. However, a gap is generated due to the difference in thermal expansion between each other, increasing leakage.

  Therefore, an object of the present invention is to improve the sealing performance and improve the reliability of the sealing device using the sealing plate installed in order to suppress the leakage from the gap between the adjacent members, in addition to the offset of the segment member. It is in providing a highly reliable sealing device.

  To achieve the above object, a sealing device of the present invention includes a plate-like elastic body, plates joined to both ends of the plate-like elastic body, and curved elastic bodies extending from each of the plates, When installed so as to straddle two seal grooves facing each other, the plate and the plate-like elastic body are configured to form different surfaces of the seal groove and a surface contact surface.

  According to the present invention, in a seal device using a seal plate installed to suppress leakage from a gap between adjacent members, the seal performance is improved in correspondence with the offset of the segment member, and the reliability is improved. A high sealing device can be provided.

It is a conceptual diagram which shows the structure of the gas turbine which concerns on the Example of this invention. It is sectional drawing of the turbine part to which the sealing device based on the Example of this invention is applied. It is a conceptual diagram which shows arrangement | positioning of the sealing device which concerns on the Example of this invention. It is a conceptual diagram of the stationary blade body which shows mounting | wearing of the sealing device based on the Example of this invention. 1 is an external view of a sealing device showing a first embodiment of the present invention. It is a conceptual sectional view at the time of seal slot wearing of the sealing device which shows the 1st example of the present invention. It is a conceptual diagram showing the state at the time of gas turbine operation | movement of the sealing apparatus which shows 1st Example of this invention. It is a conceptual diagram showing the effect | action at the time of gas turbine operation | movement of the sealing apparatus which shows the 1st Example of this invention. It is an external view of the sealing apparatus which shows the 2nd Example of this invention. It is a top view of the sealing device which shows the 3rd example of the present invention. It is an external view of the sealing apparatus which shows the 3rd Example of this invention. It is leak explanatory drawing of the sealing device which shows the 3rd Example of this invention.

〔Example〕
A first embodiment of the present invention will be described below with reference to FIGS. 1, 2, 3, 4, 5, 6, 6, 7 and 8. FIG. 1 is a conceptual diagram showing a configuration of a gas turbine according to the present embodiment, FIG. 2 is a sectional view of a turbine section according to the present embodiment, and FIG. 3 is a conceptual diagram showing an arrangement of a sealing device according to the present embodiment, 4 is a conceptual diagram of a stationary blade body showing mounting of a sealing device according to the present embodiment, FIG. 5 is an external view of the sealing device according to the first embodiment of the present invention, and FIG. 6 is a first view of the present invention. FIG. 7 is a conceptual cross-sectional view of the seal device showing the embodiment of the present invention when the seal groove is mounted, FIG. 7 is a conceptual diagram showing a state of the gas turbine operation of the seal device showing the first embodiment of the invention, and FIG. These show the conceptual diagram showing the effect | action at the time of gas turbine operation | movement of the sealing device which shows 1st Example of this invention. In each figure, the same number represents the same device, member, or function.

  The overall configuration of the gas turbine 1 will be described from the flow of working gas and cooling air with reference to FIG. The gas turbine 1 mainly includes a multi-stage turbine 4, a compressor 2 that is axially connected to the turbine and obtains compressed air for combustion, a combustor 3 that converts the compressed air into high-temperature and high-pressure gas, and a generator 5. ing. The cooling air extracted from the compressor 2 is a stationary blade low pressure cooling air path 6a for cooling the second stage stationary blade, a stationary blade high pressure cooling air path 6b for cooling the first stage stationary blade, and the first and second stage blades. Is supplied to each turbine cooled part via a moving blade cooling air path 7 for cooling the turbine.

  At this time, the extraction air pressure is selected from values corresponding to the gas path pressure in each blade, and the extraction air from the final stage of the compressor 2 is provided in the stationary blade high-pressure cooling air path 6b and the moving blade cooling air path 7. Extracted air from the intermediate pressure stage of the compressor 2 is introduced into the air and stationary blade low-pressure cooling air path 6a. Each cooling air that cools the cooled part and exchanges heat is discharged into the gas path of the turbine 4 as a film cooling of a blade (not shown) or a jet from the trailing edge of the blade, and mixed with the working gas, Ultimately, it is released into the atmosphere as exhaust gas.

  FIG. 2 is a partial turbine section showing the first stage stationary blade 10, the second stage stationary blade 12 a, the first stage moving blade 11, and the second stage moving blade 13 up to the second stage of the turbine 4. Each of the cooling air passages 6a, 6b, and 7 communicates with a blade that is a cooled part. Here, in order to clarify the sealing device of the present embodiment, a description is given around the second stage stationary blade 12a. .

  The cooling air supplied through the introduction hole (not shown) provided in the casing 14 via the stationary blade low-pressure cooling air path 6 a is supplied to the second stage stationary blade supply cavity 8 inside the outer end side of the casing 14. Then, the second stage stationary blade body 21a is annularly arranged in the circumferential direction. The second stage stationary blade body segment 21a mainly includes an outer diameter side end wall 22a, a second stage stationary blade 12a, and an inner diameter side end wall 23a. The cooling air exchanges heat when passing through a cooling path (not shown) of the second stage stationary blade body 21a, cools the end walls 22a, 23a and the second stage stationary blade 12a, rises in temperature, and is discharged into the gas path 9. The

  On the other hand, part of the air supplied to the second stage stationary blade supply cavity 8 passes through the diaphragm cavity 15 formed between the second stage stationary blade body segment 21a and the diaphragm 16a attached to the second stage stationary blade body segment 21a. After the first stage wheel 19a, the spacer 18 and the diaphragm 16a are supplied to the first stage rotor blade rear wheel space 17a, a part of the gas path between the first stage rotor blade 11 and the second stage stator blade 12a is provided. The second stage formed by the second stage wheel 19b, the spacer 18 and the diaphragm 16a after the flow rate is throttled by the seal fin 29 cooperating between the diaphragm 15 and the spacer 18 and partially flowing as seal air. It is distributed to the front blade space 17b of the moving blade, and enters the gas path 9 between the second stage stationary blade 12a and the second stage moving blade 13. It will flow as air.

  FIG. 3 shows a second stage stationary blade body segment 21a including a second stage stationary blade body 12a, which is one of the second stage stationary blade body segments arranged in the circumferential direction, and a diaphragm 16a. Seal grooves 30 and 31a and a seal groove 32 are provided on the outer diameter side end wall 22a of the second stage stationary blade body segment 21a, and seal grooves 33 and 34 and a seal groove 35 are provided on the inner diameter side end wall 23a. Yes. The diaphragm 16a is provided with seal grooves 36, 37, 38, 39, 40, 41, and a seal groove 42.

  A plurality of second stage stationary blade body segments 21a are arranged in the circumferential direction, and there is a gap between the segments. Accordingly, the second stage stationary blade supply cavity 8 and the gas path 9 communicate with each other, and conceptually, a leak flow path in the direction of the arrow from the second stage stationary blade supply cavity 8 to the gas path 9 shown in the figure is generated. The sealing grooves 30, 31a, 32 are arranged in such a manner as to shut off the second stage stationary blade supply cavity 8 on the high pressure side and the gas path 9 on the low pressure side. Similarly, leak flow paths also exist between the inner diameter side end wall 23a and the segments of the diaphragm 16a. Hereinafter, in order to further clarify the intention of the present embodiment, the seal groove 31a is focused on for sealing. Details of the apparatus will be described.

  FIG. 4 is a projection view of the second stage stationary blade body segment 21b adjacent to the second stage stationary blade body segment 21a as viewed from the outside in the radial direction. As described above, the second stage stationary blade body segment is annularly arranged as a plurality of segments in the circumferential direction, and typically shows two second stage stationary blade body segments 21a and 21b. The second stage stationary blade body segments 21a and 21b are assembled with a circumferential gap σc_cold. There is an outer diameter side end wall 22b of the second stage stationary blade body segment 21b adjacent to and opposed to the outer diameter side end wall 22a of the second stage stationary blade body segment 21a, and a seal groove 31a and a radial groove facing each circumferential direction. , 31b are formed. The seal plate 50 is mounted so as to block the circumferential gap σc_cold by straddling both the seal grooves. As a result, the leak path from the second stage stationary blade supply cavity 8 to the gas path 9 is blocked in the radial direction.

  Here, terms are defined. For example, the seal plate 50 attached to the seal grooves 31a and 31b has an upstream end surface 24 on the side (left side in the drawing) into which the working gas flows, and conversely, the working gas is discharged. Although the downstream end surface 25 is provided on the side (right side in the drawing), the direction connecting the upstream end surface 24 and the downstream end surface 25, that is, the direction connecting both end surfaces of the plate, is the longitudinal direction of the seal groove. Call. For example, following this, the longitudinal direction of the seal groove 32 is the vertical direction of FIG.

  FIG. 5 shows the appearance of a seal plate 50 which is a sealing device according to the present embodiment. The seal plate 50 has two rectangularly sectioned plates 51a and 51b that are equally extended in the longitudinal direction. The plate springs 52, which are plate-like elastic bodies, are arranged on the plates 51a, 51b. It joins over the longitudinal direction like 51b. Further, curved elastic bodies 53a and 53b, which are plate-like members, extend from the surface opposite to the surface where the plate springs 52 of the plates 51a and 51b are joined. The curved elastic bodies 53 a and 53 b have their ends 57 a and 57 b curved and inverted so as to go inward of the seal plate 50, and extend in the longitudinal direction in the same manner as the leaf spring 52. Accordingly, the length of each member in the longitudinal direction is the same for the plates 40a and 40b, the leaf spring 52, and the curved elastic bodies 53a and 53b.

  FIG. 6 shows the seal plate 50 as a cross section during assembly in which the seal plate 50 is installed so as to straddle the seal grooves 31a and 31b. A circumferential gap σc_cold is provided between the outer diameter side end wall 22a and the adjacent outer diameter side end wall 22b, and is orthogonal to the gap surfaces 68a and 68b of the outer diameter side end walls 22a and 22b. The seal groove 31a and the seal groove 31b are provided to face each other.

  The plate 51a is in surface contact with the inner diameter side seal surface 66a of the seal groove 31a to form a contact seal surface 61a. The curved elastic body 53a extends from the plate 51a in a direction opposite to the leaf spring 52 extending from the plate 51a and curves, and then comes into surface contact with the outer diameter side seal surface 67a to form a contact seal surface 60a. 57a remains in the groove depth (left and right direction of the drawing) of the seal groove 31a. Similarly, the plate 51b is in surface contact with the inner diameter side seal surface 66b of the seal groove 31b to form a contact seal surface 61b. Further, the curved elastic body 53b extending from the plate 51b also comes into surface contact with the outer diameter side seal surface 67b to form a contact seal surface 60b.

  As described above, the plates 51a and 51b and the curved elastic bodies 53a and 53b form a seal surface in the seal groove in an independent manner with respect to both the seal grooves 31a and 31b, and the plate spring 52 and the plate 51a and The plate 51b is joined in the seal groove depth direction.

  In the present embodiment configured as described above, the plurality of second stage stationary blade body segments are incorporated into one ring shape while being slid in an annular shape, but the seal plate 50 is sealed by the spring force of the curved elastic body. Since the groove is easily fixed in the groove, the second stage stationary blade segment can be assembled relatively easily.

  The high-temperature and high-pressure working gas generated in the compressor 2 and the combustor 3 along with the operation of the gas turbine 1 has a pressure of about 1.6 MPa and a temperature of about 1300 ° C., and flows into the inlet of the first stage stationary blade 10 a inside the turbine. Hereinafter, in each rotor stage including the first stage rotor blade 10b, the pressure and temperature are reduced while changing the fluid energy to the rotational energy of the turbine, and after the final stage rotor blade flows out at about 600 ° C., the exhaust gas is discharged. Is done. At this time, the generator 5 directly connected to the gas turbine 1 rotates to obtain electric power.

  Since the turbine blades are exposed to high-temperature gas, a part of the high-pressure air obtained by the compressor 2 is extracted and used as cooling air. This cooling air is divided into a stationary blade and a moving blade, and the stationary blade is also extracted from the appropriate pressure. The second-stage stationary blade included in the stationary blade low-pressure cooling air path 6a is supplied to the second-stage stationary blade 12a, which is one of the segments. It is introduced into the second stage stationary blade segment 21 via the cavity 8.

  FIG. 7 shows a conceptual diagram of the seal plate 50 during operation of the gas turbine. Along with the operation of the gas turbine, the temperature of each gas turbine member rises using the working gas or cooling air as a heating source. As one of them, the second stage stationary blade body segments 21a and 21b undergo thermal expansion, but in the circumferential direction, the segment gap σc_cold during assembly is narrowed to σc_hot. However, since the gap σc_hot is designed not to contact even in the rated point operation of the gas turbine, it does not become zero. At this time, in conjunction with the movement of the second stage stationary blade body segments 21a, 21b, the outer diameter side end walls 22a, 22b and the seal grooves 31a, 31b also move toward the gap direction in the figure. The plate 50 absorbs the displacement of the seal grooves 31 a and 31 b by sliding on the contact seal surfaces 60 a, 60 b, 61 a and 61 b and elastic deformation of the plate spring 52.

  On the other hand, in the second stage stationary blade body segments 21a and 21b, a radial thermal expansion deviation due to a thermal deviation on thermal flow and a radial displacement of σr due to working fluid force and manufacturing tolerance of the member occur, and the seal groove has an offset. Arise. This offset causes a step in the radial direction between the contact seal surface 60a and the contact seal surface 60b, and between the contact seal surface 61a and the contact seal surface 61b. Since the plate spring 52 absorbs the displacement due to this step, The contact seal surfaces 60a, 60b, 61a, 61b are held by the surface contact seal surfaces in the same manner as in assembly.

  Details of holding the surface contact seal surface will be described with reference to a conceptual diagram showing the operation of the seal plate of FIG. 8 during gas turbine operation. Although FIG. 8 shows only the seal groove 31a side, the same applies to the seal groove 31b side. As described above, the cooling air supplied to the second stage stationary blade body segment cools the portion to be cooled of the second stage stationary blade body segment (not shown) and then discharges it to the gas path 9, including the pressure loss at the portion to be cooled. It is necessary to supply a pressure higher than that of the gas path 9 to the second stage stationary blade supply cavity 8.

  That is, if the supply pressure of the second stage stationary blade supply cavity 8 is P1, and the pressure of the gas path 9 is P2, the relation of P1> P2 is established. A pressure P1 is added to the leaf spring 52 as an arrow 62a, and a pressure P2 is added as an arrow 62b. Half of the fluid force obtained by multiplying this pressure difference ΔP12 by a pressure receiving area (not shown) of the leaf spring 52 is obtained. , Acting as an arrow 63 at the joint point of the leaf spring 52 of the plate 51a.

  On the other hand, the curved elastic body 53a is brought into close contact with the contact seal surface 60a by the spring force indicated by the arrow 64 to enhance the surface seal, and the spring reaction force indicated by the arrow 65 is joined to the curved elastic body 53a of the plate 51a. Acts on a point. Therefore, the fluid force and the spring reaction force on the plate 51a enhance the surface seal of the contact seal surface 61a. Further, since the terminal end 57a of the curved elastic body 53a is within the groove depth range of the seal groove, the spring reaction force can be fully utilized and the adhesion of the face seal can be enhanced.

  Therefore, since the surface contact is reliably maintained, leakage during this period is suppressed. That is, since the communication by the segment gap σc_hot between the second stage stationary blade supply cavity 8 and the gas path 9 is interrupted at all times during operation, the leakage flow rate from this point can be reduced.

  In the gas turbine sealing device mounted between the segments described above, by connecting two plates respectively joined to both ends of the leaf spring and a curved elastic body extending from each of the two plates. In addition to improving the efficiency of assembly of the seal plate and second stage stationary blade body segment and reducing the leak flow rate corresponding to the offset, the deformation of the seal plate caused by the offset or the stress applied to the seal groove edge via the plate It is possible to provide a highly reliable sealing device that can prevent occurrence of damage and prevent damage and destruction.

  In this embodiment, the seal plate provided in the pair of opposed seal grooves provided on the outer diameter side end wall of the second stage stationary blade body has been described as an example. It is self-evident that even if the seal plate is applied to the seal groove provided in, a greater effect can be expected. Further, it is natural that the same effect can be achieved even when the offset σr caused by the offset is set to a negative σr.

  Further, although the manufacturing method for the seal plate is not mentioned, in the present embodiment in which the plate, the plate spring, and the plate are manufactured as a single unit and then assembled, the curved elastic body and the plate spring are particularly used. Alternatively, it is common sense to take a technique for preventing the occurrence of leakage from the joined portion with respect to the joining of the plate and the curved elastic body. For example, the joining and sealing may be performed using pressure welding or laser welding. It is obvious from the gist of the present invention. Furthermore, although the plate has a rectangular cross section, it is obvious that the cross-sectional shape is not limited to this as long as securing the contact seal surface is the most important and does not hinder the joining of the leaf spring or the curved elastic body. It is.

  Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 9 shows an external view of a seal plate according to the second embodiment of the present invention, and it is assumed that the seal plates 31a and 31b are mounted as in the first embodiment. In each figure, the same number represents the same device, member, or function as in the first and second embodiments.

  In the seal plate 50, a pair of curved elastic bodies 53a, 53b and a bellows plate 54 extending in the longitudinal direction are integrally formed, and on the linear portion outer surfaces 58a, 58b of the curved elastic bodies 53a, 53b on the bellows plate 54 side, Two plates 51a and 51b having a rectangular cross section and extending equally in the longitudinal direction are joined. At this time, the terminal ends 57 a and 57 b of the curved elastic bodies 53 a and 53 b are directed inward of the seal plate 50. Further, the lengths in the longitudinal direction are substantially equal.

  In this embodiment configured as described above, along with the operation of the gas turbine, the outer diameter side end walls 22a and 22b, as well as the seal grooves 31a and 31b are linked with the movement of the second stage stationary blade body segments 21a and 21b. However, the seal plate 50 absorbs the displacement by sliding on the contact seal surfaces 60 a, 60 b, 61 a, 61 b and elastic deformation of the bellows plate 54. On the other hand, in the second stage stationary blade body segments 21a and 21b, a radial thermal expansion deviation due to a thermal deviation in thermal flow and a step of σr due to working fluid force and manufacturing tolerance of the member occur, and an offset occurs in the seal groove. This offset causes a step in the radial direction between the contact seal surface 60a and the contact seal surface 60b, and between the contact seal surface 61a and the contact seal surface 61b, but the bellows plate 54 absorbs displacement due to this step, The contact seal surfaces 60a, 60b, 61a, 61b can hold the surface contact seal surfaces as in assembly.

  On the other hand, since the curved elastic bodies 53a and 53b and the bellows plate 54 are integrally formed and do not have a joint portion, a leak related to this member occurs except for the minimum flow rate at the contact seal surfaces 60a and 60b. There is nothing. Strictly speaking, there is a leak from the end in the longitudinal direction, but since this is a leak of a form different from the gist of the present invention, it is not mentioned here.

  In the gas turbine sealing device mounted between the segments described above, the leak flow rate reduction corresponding to the offset is realized by joining the two separated plates with the integrated bellows plate and the curved elastic body. Needless to say, the flow rate can be reliably reduced, and the deformation of the seal plate caused by the offset or the generation of stress on the edge of the seal groove through the plate can be prevented to prevent damage and destruction. A highly reliable sealing device that can be obtained can be obtained, and a gas turbine that can sufficiently exhibit its effects can be provided.

  In this embodiment, the elastic body corresponding to the bonding between the plates is described as the bellows plate and integrated with the curved elastic body. However, if the plate itself is also integrated, the effect of reducing the leakage flow rate is more reliable. It is obvious to increase.

  Next, a third embodiment of the present invention will be described with reference to FIG. 3, FIG. 10, FIG. 11, and FIG. FIG. 3 is a conceptual diagram showing the arrangement of the seal plate according to the present invention, FIG. 10 is a plan view of the seal plate according to the third embodiment of the present invention, and FIG. 11 is the seal plate according to the third embodiment of the present invention. FIG. 12 is an external view and FIG. 12 is an explanatory view of the leak of the seal plate showing the third embodiment of the present invention. In each figure, the same number represents the same device, member, or function as in the first embodiment.

  As shown in FIG. 3, a plurality of seal plates are arranged so as to block the high-pressure side and the low-pressure side. In this embodiment, paying attention to the seal plates attached to the seal grooves 38, 39, 40. explain. These seal grooves are arranged to suppress leakage of the seal air supplied to the first stage rotor blade rear wheel space 17a to the gas path side 9.

  The external structure of the seal plate 50 according to this embodiment will be described with reference to FIG. In the seal plate 50, two plates 51a and 51b having a rectangular cross section are arranged apart from each other, and a plate spring 52 is joined to both the plates 51a and 51b. Further, curved elastic bodies 53 a and 53 b extend from the plates 51 a and 51 b in the direction opposite to the joining side of the leaf spring 52, respectively, and the terminal ends 57 a and 57 b face inward of the seal plate 50.

  The plate 51a and the plate 51b have different lengths in the longitudinal direction. The upstream end surface 26a and the downstream end surface 26b of the plate 51a are based on the upstream end surface 27a and the downstream end surface 27b of the plate 51b. Are both made longer by δg. Each length in the longitudinal direction is the same as that of the plate 51b for the leaf spring 52 and the curved elastic bodies 53a and 53b. The material of the plates 51a and 51b has a larger linear expansion coefficient than the material used for the diaphragm 16a.

  The upstream and downstream end surfaces 26a and 26b of the plate 51a respectively hold a gap of δg toward the upstream and downstream end surfaces 27a and 27b of the plate 51b. 55b are joined together. The height of the side end plates 55a and 55b in the depth direction in the drawing is set to be smaller than the maximum height of the curved elastic body based on the contact seal surface of the plate. Note that δg is a minute gap that does not hinder the movement of the curved elastic body in the radial direction.

  FIG. 11 shows a combination arrangement of the seal plate 50 mounted in the seal groove 39 (not shown) and the seal plate 56a mounted in the adjacent seal groove 38 (not shown) orthogonal to the width direction. An assembly external view is shown. Between the side end plate 55a of the seal plate 50 and the seal plate 56a, there is a gap δa, which is incorporated in the seal groove, where δa is the thermal expansion of the diaphragm 16a, the seal plate 50, and the seal plate 56a. Given from the quantity. The seal surface of the seal plate 56a adjacent to each other which cooperates with the side end plate 55a is a flat plate. Here, the description has been made focusing on the side end plate 55a, but the same applies to the side end plate 55b of the seal plate 50.

  A conceptual leak path from the first stage blade rear wheel space 17a toward the gas path 9 in the assembled state by this seal plate arrangement will be described. The leak path is indicated by an arrow 71a from a contact seal surface (not shown) formed by a seal groove (not shown) and a curved elastic body 53b via a contact seal surface (not shown) formed by a seal groove (not shown) and a plate 51b. Route, side indicated by an arrow 71b from a contact seal surface (not shown) formed by a seal groove (not shown) and a curved elastic body 53a via a seal groove (not shown) formed by a path, a seal groove (not shown) and the plate 51a A path indicated by an arrow 71c from a contact seal surface (not shown) formed by the end plate 55a and the seal plate 56a, and a path indicated by an arrow 71d from a contact seal surface (not shown) formed by the side end plate 55b and a seal plate (not shown). In addition, the path on the side end plate 55a side (not shown) by δg set at the time of joining, and the side end plate 5 There is a path indicated by b in the arrow 72b.

  The leak path in the vicinity of the side end plates 55a and 55b will be described in detail with reference to FIG. FIG. 12 is a cross-sectional view of the seal plate 50 in FIG. A seal plate 50 is attached to the seal groove 39, and seal plates 56 a and 56 b are attached to the seal grooves 38 and 40 adjacent to each other at right angles. In this case, the main leak path is a leak path indicated by an arrow 71c by δa between the side end plate 55a and the seal plate 56a, a leak path indicated by an arrow 71d by δa between the side end plate 55a and the seal plate 56b, and the side There are a leak path indicated by an arrow 72a by δg in the end plate 55a and a leak path indicated by an arrow 72b by δg in the side end plate 55b.

  In this embodiment configured as described above, the seal groove is displaced in conjunction with the operation of the diaphragm as the gas turbine is operated. At this time, for the leak paths 71a and 71b, the leaf spring 52 absorbs the displacement with respect to the circumferential displacement and offset. Further, strong contact seal surfaces 60a, 60b, 61a, 61b are formed between the seal groove and the fluid force and spring force of the plate and the curved elastic body, and the leak paths 71a, 71b are blocked. Become.

  On the other hand, at the side end portion of the seal plate 50, the gap δa is reduced by the difference in thermal expansion between the diaphragms 51a and 51b having a larger linear expansion coefficient than that of the diaphragm and finally becomes zero. That is, since the flat contact seal surface 75a is formed between the seal plate 56a and the side end plate 55a, and the flat contact seal surface 75b is formed between the seal plate 56b and the side end plate 55b, the leak paths 71c and 71d are blocked. Is done.

  Further, the thermal expansion of the plates 51a and 51b due to the difference in thermal expansion proceeds until the rated operation state of the gas turbine, but the contact seal surfaces 76a and 76b with the seal grooves of the seal plates 56a and 56b are not expanded. This is an absolute restraint point. Therefore, the contact seal surfaces 75a and 75b obtained by reducing the plate thickness of the seal plates 56a and 56b serve as a restraint condition for the seal plate 50, and the plates 51a and 51b extend by pushing the side end plates 55a and 55b, respectively. . As a result, the side end plates 55a and 55b are elastically deformed by the thermal expansion force of the plate, but the deformed portion of the material is directed inward of the seal plate 50 due to the restraint at the contact seal surfaces 75a and 75b. In other words, the side end plates 55a and 55b cover the gap of δg and block the leak paths 72a and 72b.

  In the gas turbine sealing device mounted between the segments described above, the plate includes two plates joined to both ends of the leaf spring, and a curved elastic body extending from each of the plates, and the longitudinal end surface of one plate By providing the side plate with the side plate, it is possible to obtain a seal device that can prevent leakage between the seal plates adjacent to each other as well as reducing the leak flow rate corresponding to the offset. Moreover, since the leak of the adjacent seal plate itself can be suppressed, a highly reliable sealing device can be provided.

  Moreover, since the height of the side end plates 55a and 55b is set to be smaller than the maximum height of the curved elastic body with reference to the contact seal surface of the plate, it can be easily attached to the seal groove.

  In this embodiment, the upstream and downstream end surfaces 26a and 26b of the plate 51a are both long with reference to the upstream end surface 27a and the downstream end surface 27b of the plate 51b. It is obvious that even if the length is different, the effect of the present embodiment is not hindered. Further, regarding the attachment of the side end plates 55a and 55b, it is assumed that a constant minute gap δg is maintained. However, since the elastic body eventually covers this gap, the condition is not limited to the fixed gap. .

  Moreover, although it demonstrated as a seal plate which adjoins orthogonally, even if this inclines, it is clear that it can respond easily by the attachment of the side end plate corresponding to this, and the shape change of a side plate plate. Further, although the embodiment has been described with a part of the seal plate of the diaphragm, the effect can be further expected if it is applied to the same seal groove constituent portion. In the present embodiment, the material of the side end plate is not mentioned, but not only the elastic force as a material but also a structural elastic body incorporating an expanded metal may be used.

DESCRIPTION OF SYMBOLS 1 Gas turbine 4 Turbine 31a Seal groove 50 Seal plate 51a, 51b Plate 52 Leaf spring 53a, 53b Curved elastic body 54 Bellows plate 55a, 55b Side end plate

Claims (6)

  A plate-like elastic body, a plate joined to both ends of the plate-like elastic body, and a curved elastic body extending from each of the plates, and when installed so as to straddle two opposing seal grooves, A sealing device configured such that a plate and a first surface of the seal groove form a surface contact surface, and the curved elastic body and a second surface of the seal groove form a surface contact surface.   2. The sealing device according to claim 1, wherein the curved elastic body has a shape that is curved and inverted after extending in a direction opposite to the plate-shaped elastic body, and when the curved elastic body is installed in the seal groove, The sealing device is configured such that the end when the joint portion is the starting end is within the range of the groove depth of the seal groove.   3. The sealing device according to claim 1, wherein at least the plate-like elastic body and the curved elastic body are integrally formed. 4. The sealing device according to claim 1, wherein a side end plate configured to extend from an end surface in one longitudinal direction of the plates and to have a gap on an end surface of the other plate. 5. Prepared,
The side end plate has a height within a range of a maximum height of the curved elastic body based on a surface forming the surface contact surface with the first surface of the seal groove of the plate, A sealing device comprising a body material.   5. The sealing device according to claim 4, further comprising a seal plate for forming a surface contact with the side end plate so that a flat surface contact surface is formed by the seal plate and the side end seal plate. It is comprised, The sealing device characterized by the above-mentioned. In the gas turbine, which is composed of a compressor, a combustor, and a turbine having a stationary blade and a moving blade, and the constituent members are divided into a plurality of segments in the circumferential direction of the turbine,
A seal groove is provided to face each of the gap surfaces where the adjacent segments face each other,
A sealing device having a plate-like elastic body, plates joined to both ends of the plate-like elastic body, and a curved elastic body extending from each of the plates is installed so as to straddle the two seal grooves facing each other And
The gas characterized in that the plate and the first surface of the seal groove form a surface contact surface, and the curved elastic body and the second surface of the seal groove form a surface contact surface. Turbine.