JP2012225207A - Gas turbine moving blade and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve an output and/or energy efficiency of a gas turbine with a gas turbine moving blade configured to cool a tip shroud by cooling air.SOLUTION: The gas turbine moving blade 1 includes an airfoil section 3, a tip shroud 4 joined to the tip of the airfoil section 3, and a fin 5 arranged on its outer peripheral surface. The airfoil section 3 is configured to supply the cooling air to the tip shroud 4. The tip shroud 4 is configured to discharge the cooling air supplied via the internal space thereof. The tip shroud 4 is configured so that a flow rate of the cooling air discharged from the tip shroud 4 to a high pressure side area which is on the upstream side of a flow of hot gas with respect to the fin is higher than a flow rate of the cooling air discharged from the tip shroud to a low pressure side area which is downstream with respect to the fin 5.

Description

  The present invention relates to a gas turbine blade and a manufacturing method thereof, and more particularly to a cooling structure for a tip shroud of a gas turbine blade.

  A structure called a tip shroud, which protrudes in the axial direction and the circumferential direction of the gas turbine, is often attached to the tip of the gas turbine blade. The chip shroud generally has two roles. One is to introduce more hot gas from the combustor to the blade surface of the gas turbine blade to improve energy efficiency. The other is that when the gas turbine is operated and the gas turbine blade is rotating at a high speed, the tip shrouds of adjacent gas turbine blades are brought into contact with each other, thereby suppressing the vibration of the gas turbine blade. That is.

  During operation of the gas turbine, the temperature of the gas turbine rotor blade becomes high, so that the gas turbine rotor blade is cooled by supplying cooling air to the internal space of the gas turbine rotor blade. At this time, the chip shroud is similarly cooled by the cooling air by supplying the cooling air to the internal space.

  Japanese Patent Application Laid-Open No. 11-13402 and Japanese Patent No. 3340301 disclose a technique for cooling a chip shroud by providing a cooling passage in the chip shroud. Japanese Unexamined Patent Publication No. 2009-168017 discloses a technique for cooling a chip shroud by providing a cooling cavity inside the chip shroud.

  In the structure of the gas turbine rotor blade disclosed in these patent documents, the tip shroud is provided with fins protruding in the radial direction of the gas turbine. The fin is a structure for improving the energy efficiency by reducing the clearance between the tip of the gas turbine rotor blade and the casing located on the outer periphery thereof. The upstream side where the high-temperature gas flows across the fin is a relatively high pressure region, and the opposite side (downstream side) is a relatively low pressure region. The structure of the chip shroud disclosed in the above three patent documents is configured such that the cooling air is discharged into both the high pressure region and the low pressure region.

  However, according to the inventors' investigation, the structure of the chip shroud disclosed in the above patent document has room for improvement in the output and energy efficiency of the gas turbine.

  JP 2007-77986 A, JP 2006-105084 A, and JP 2008-95695 A disclose a cooling structure of a tip portion of a gas turbine rotor blade. However, these patent documents do not relate to cooling of a gas turbine blade provided with a tip shroud.

Japanese Patent Laid-Open No. 11-13402 Japanese Patent No. 3403501 JP 2009-168017 A JP 2007-77986 A JP 2006-105084 A JP 2008-95695 A

  Accordingly, an object of the present invention is to provide a technique for improving the output and / or energy efficiency of a gas turbine for a gas turbine rotor blade having a structure for cooling a tip shroud with cooling air.

  In one aspect of the present invention, a gas turbine rotor blade that operates by receiving a high-temperature gas includes an airfoil portion having a blade surface formed thereon, an inner peripheral surface joined to the tip of the airfoil portion, and the inner peripheral surface. A chip shroud having opposing outer peripheral surfaces and fins provided on the outer peripheral surface are provided. The airfoil is configured to supply cooling air to the tip shroud. The chip shroud is configured to discharge cooling air supplied through its internal space. Here, the flow rate of the cooling air discharged from the chip shroud to the high-pressure side region upstream of the high-temperature gas flow from the fins is from the chip shroud to the low-pressure side region downstream of the fins from the high-temperature gas flow. More than the flow rate of the cooling air released. In such a gas turbine rotor blade, the cooling air released to the high-pressure side region works on the gas turbine rotor blade, so that the output and / or energy efficiency of the gas turbine can be improved.

  In order to further improve the output and / or energy efficiency of the gas turbine, it is desirable that the flow rate of the cooling air discharged to the high pressure side region is 70% or more of the total amount of cooling air supplied to the chip shroud. Further, in order to further improve the output and / or energy efficiency of the gas turbine, it is preferable that the entire amount of cooling air supplied to the chip shroud is discharged to the high pressure side region.

  As an additional method of improving the output and / or energy efficiency of the gas turbine, a cooling air flow rate of more than 50% of the total amount of cooling air supplied to the chip shroud is opposite to the rotation direction of the gas turbine blades. It is preferably released from the tip shroud to have a directional velocity component. In this case, 70% or more of the cooling air supplied to the tip shroud may be discharged from the tip shroud so as to have a velocity component in the direction opposite to the rotation direction of the gas turbine rotor blade. More preferably, in order to further improve the output and / or energy efficiency of the gas turbine, the tip of the cooling air supplied to the tip shroud has a velocity component in the direction opposite to the rotational direction of the gas turbine blade. Preferably it is released from the shroud.

  In one embodiment, the airfoil has a cooling passage for supplying cooling air to the tip shroud, and the tip shroud has a cooling air hole for discharging the cooling air supplied from the cooling passage.

  In another embodiment, the airfoil has a cavity for supplying cooling air to the tip shroud, and the tip shroud has a plurality of cooling air holes for discharging cooling air supplied from the cavity.

  In yet another embodiment, the airfoil has a plurality of cooling passages for supplying cooling air to the tip shroud, and the tip shroud is connected to the cavities communicating with the plurality of cooling passages and the cooling for releasing the cooling air. And air holes.

  In yet another embodiment, the tip shroud extends from the position supplied from the airfoil in a direction having a component in the downstream direction of the hot gas to reach a specific position, and is provided in the high pressure side region from the specific position. A flow path communicating with the formed opening. At least a part of the cooling air supplied to the chip shroud is discharged from an opening provided in the high pressure side region.

  In another aspect of the present invention, a method for manufacturing a gas turbine rotor blade includes a step of creating a through hole penetrating a position of a high pressure side region and a position of a low pressure side region of a chip shroud; And forming a cooling air hole by closing.

  In still another aspect of the present invention, a method for manufacturing a gas turbine rotor blade includes: a plurality of through holes penetrating a position of a high pressure side region and a position of a low pressure side region of a chip shroud; A step of forming a communication portion that opens to the low-pressure side region, and a step of closing the communication portion in the low-pressure side region to form a cooling air hole. In this case, the through hole and the communication portion may be formed by inserting a discharge electrode composed of a plurality of discharge rods and a root portion supporting the discharge rod into the chip shroud.

  ADVANTAGE OF THE INVENTION According to this invention, the output and / or energy efficiency of a gas turbine provided with the gas turbine rotor blade which has a structure which cools a chip | tip shroud with cooling air can be improved.

It is a side view which shows the structure of the gas turbine rotor blade of one Embodiment of this invention. It is a top view which shows the structure seen from the outer peripheral side of the gas turbine rotor blade of FIG. It is sectional drawing which shows the structure of the gas turbine rotor blade of FIG. It is a top view which shows the structure of the chip | tip shroud in one Embodiment of this invention. It is a top view which shows the structure of the chip | tip shroud in one Embodiment of this invention. 4B is a cross-sectional view showing the structure of the chip shroud of FIGS. 4A and 4B. FIG. 4B is a cross-sectional view showing the structure of the chip shroud of FIGS. 4A and 4B. FIG. It is sectional drawing which shows the other structure of a chip | tip shroud. 4A and 4B are conceptual diagrams illustrating advantages of the chip shroud illustrated in FIGS. 4A and 4B. 4A and 4B are conceptual diagrams illustrating advantages of the chip shroud illustrated in FIGS. 4A and 4B. It is a graph which shows an example of the relationship between the ratio of the cooling air discharge | released to the high voltage | pressure side area | region of a chip shroud, and the temperature rise of the low voltage | pressure side area | region of a chip shroud. It is a top view which shows the structure of the chip | tip shroud for improving the output and / or energy efficiency of a gas turbine further. It is a top view which shows the other structure of the chip | tip shroud for improving the output and / or energy efficiency of a gas turbine further. It is sectional drawing which shows the structure of the gas turbine rotor blade of other embodiment of this invention. FIG. 10 is a plan view showing a structure of a tip shroud of the gas turbine rotor blade of FIG. 9. It is a top view which shows the structure of the chip | tip shroud in other embodiment of this invention. It is sectional drawing which shows the structure of the chip | tip shroud of FIG. It is a top view which shows the structure of the chip | tip shroud in other embodiment of this invention. It is a top view which shows the manufacturing process of a gas turbine rotor blade provided with the chip | tip shroud of the structure of FIG. It is a top view which shows the manufacturing process of a gas turbine rotor blade provided with the chip | tip shroud of the structure of FIG. It is sectional drawing which shows the structure of the chip | tip shroud in further another embodiment of this invention. It is sectional drawing which shows the structure of the chip | tip shroud in further another embodiment of this invention. It is a side view which shows the structure of the chip | tip shroud provided with a some fin.

  FIG. 1 is a side view showing the structure of a gas turbine blade according to an embodiment of the present invention. The gas turbine rotor blade 1 generally includes a blade root 2 connected to a rotor disk (not shown) of the gas turbine, an airfoil 3 on which a blade surface is formed, and a tip of the airfoil 3. The tip shroud 4 is joined, and the fin 5 is joined to the outer peripheral surface of the tip shroud 4 (the surface facing the surface (inner peripheral surface) to which the airfoil portion 3 is bonded). The fins 5 are provided so as to protrude from the outer peripheral surface of the chip shroud 4 to the outer side in the radial direction of the rotor disk.

  FIG. 2 is a top view showing the structure of the tip shroud 4 and the fins 5 joined thereto. The gas turbine rotor blades 1 are arranged side by side in the circumferential direction of the rotor disk. The tip shrouds 4 of the adjacent gas turbine rotor blades 1 are close to each other, and during operation of the gas turbine, the portion A of the adjacent tip shroud 4 abuts autonomously as the gas turbine rotor blade 1 rotates at high speed. . This contributes to reducing the vibration of the gas turbine rotor blade 1 during operation. The fins 5 are provided so as to extend in the circumferential direction of the rotor disk. The upstream side where the high temperature gas flows across the fin 5 is a relatively high pressure region, and the opposite side (downstream side) is a relatively low pressure region. Hereinafter, the region on the upstream side of the flow of the hot gas from the fin 5 may be referred to as a high pressure side region, and the region on the downstream side may be referred to as a low pressure side region.

  FIG. 3 is a cross-sectional view showing the structure of the gas turbine rotor blade 1 of FIG. The gas turbine rotor blade 1 has a structure that is cooled by the cooling air 7 supplied to the blade root portion 2. Specifically, a cavity 11 is provided in a portion of the airfoil 3 close to the blade root 2, and a pin fin 12 is provided inside the cavity 11. The portion of the airfoil 3 close to the blade root 2 is effectively cooled by disturbing the flow of the cooling air 7 by the pin fins 12. On the other hand, a cooling channel 13 extending in a direction substantially parallel to the radial direction of the rotor disk is provided at a portion near the tip of the gas turbine rotor blade 1. The cooling flow path 13 extends to the inside of the tip shroud 4 provided at the tip of the airfoil 3, and the cooling air 7 is introduced into the tip shroud 4 through the cooling flow path 13.

  4A and 4B are plan views showing the structure of the chip shroud 4 in one embodiment of the present invention, FIG. 5A is a cross-sectional view taken along the line AA in FIGS. 4A and 4B, and FIG. It is sectional drawing in a BB cross section. Inside the tip shroud 4, a cooling air hole 6 communicating with the cooling flow path 13 of the airfoil 3 is provided. The cooling air 7 is introduced from the cooling flow path 13 into the cooling air hole 6, whereby the chip shroud 4 is cooled.

  One feature of the gas turbine rotor blade 1 of the present embodiment is that the cooling air 7 is discharged from the cooling air holes 6 of the tip shroud 4. In the gas turbine rotor blade 1 of the present embodiment, the flow rate of the cooling air 7 released to the high pressure side region of the cooling air 7 supplied to the tip shroud 4 is greater than the flow rate of the cooling air 7 released to the low pressure side region. Or the entire amount of the cooling air 7 supplied to the chip shroud 4 is discharged to the high pressure side region. As described above, the high-pressure side region is a region located on the upstream side of the high-temperature gas from the fin 5, and the low-pressure side region is a region located on the downstream side of the fin 5.

  Here, FIG. 4A illustrates an example of a structure in which the flow rate of the cooling air 7 discharged to the high pressure side region is larger than the flow rate of the cooling air 7 discharged to the low pressure side region. In the chip shroud 4 in FIG. 4A, the cooling air hole 6a discharges the cooling air 7 to the low pressure side region among the nine cooling air holes 6 shown in the figure, and the other cooling air holes 6 are in the high pressure side region. Cooling air 7 is discharged. On the other hand, FIG. 4B illustrates a structure in which the entire amount of the cooling air 7 discharged from the cooling air hole 6 of the chip shroud 4 is discharged to the high pressure side region.

  6A and 6B show that the flow rate of the cooling air 7 released to the high pressure side region is larger than the flow rate of the cooling air 7 released to the low pressure side region or the cooling air 7 supplied to the chip shroud 4. It is a conceptual diagram which shows the advantage of the structure where the whole quantity is discharge | released to the high voltage | pressure side area | region. As shown in FIG. 6A, the cooling air 7 discharged from the cooling air hole 6 of the tip shroud 4 to the low pressure side region flows downstream without performing work on the gas turbine rotor blade 1. On the other hand, as shown in FIG. 6B, the cooling air 7 discharged from the cooling air hole 6 of the tip shroud 4 to the high-pressure side region works on the gas turbine rotor blade 1, and the gas turbine rotor blade 1. A driving force for rotating the is generated. Accordingly, the flow rate of the cooling air 7 released to the high pressure side region is larger than the flow rate of the cooling air 7 released to the low pressure side region, or the total amount of the cooling air 7 discharged from the cooling air hole 6 is high pressure side. By adopting a structure that is released into the region, the power and / or energy efficiency of the gas turbine can be improved. Here, a part of the cooling air 7 discharged to the high pressure side region can pass through the tip clearance 9 a between the casing 9 and the fin 5. However, since the flow rate of the cooling air 7 passing through the tip clearance 9a is relatively small, the influence on the effect of working on the gas turbine rotor blade 1 is small.

  Here, from the viewpoint of improving the output and / or energy efficiency of the gas turbine, it is advantageous that the flow rate of the cooling air 7 discharged to the high pressure side region is large. For example, when the total amount of the cooling air 7 supplied to the chip shroud 4 is 100%, the ratio of the flow rate of the cooling air 7 discharged to the high-pressure side region is preferably 70% or more. Further, from the viewpoint of improving the output and / or energy efficiency of the gas turbine, it is most advantageous that the entire amount of the cooling air 7 supplied to the chip shroud 4 is discharged to the high pressure side region.

  On the other hand, however, if the flow rate of the cooling air 7 discharged to the high pressure side region is large and the flow rate of the cooling air 7 discharged to the low pressure side region is too small, the chip shroud 4 is positioned in the low pressure side region. There is a possibility that the cooling of the portion to be performed becomes insufficient. FIG. 7 shows the ratio of the flow rate of the cooling air 7 discharged to the high pressure side region when the total flow rate of the cooling air 7 supplied to the chip shroud 4 is constant at a specific value, and the low pressure side of the chip shroud 4. It is a graph which shows the relationship of the temperature rise of the member of the part located in an area | region. The temperature rise is defined as 0 when the proportion of the flow rate of the cooling air 7 discharged to the high-pressure side region is 50%. From the viewpoint of strength, the temperature increase of the member in the chip shroud 4 is preferably 20 ° C. or less. In this case, according to FIG. 7, the flow rate of the cooling air 7 discharged to the high-pressure side region from the viewpoint of the temperature increase. The occupation ratio is limited to 70% or less. In this case, it is preferable that the ratio of the flow rate of the cooling air 7 discharged to the high pressure side region is 70%.

  However, as will be described later, at least one of the plurality of cooling air holes 6 passes through the low pressure side region of the chip shroud 4 and then discharges the cooling air 7 to the high pressure side region. If so, the problem of cooling the portion located in the low pressure side region of the tip shroud 4 is small. In this case, the proportion of the flow rate of the cooling air 7 discharged to the high pressure side region can be increased, and depending on the design, the entire amount of the cooling air 7 discharged from the cooling air hole 6 is released to the high pressure side region. It is also possible to adopt a structure.

  4A, 4B, 5A and 5B, the side surface of the tip shroud 4 (that is, the inner peripheral surface to which the airfoil portion 3 is bonded and the outer peripheral surface to which the fins 5 are bonded) The cooling air hole 6 is opened on the surface connecting the two. However, as illustrated in FIG. 5C, the cooling air holes 6 may be opened on the outer peripheral surface to which the fins 5 are joined. FIG. 5C shows a cooling air hole 6 for discharging the cooling air 7 from the outer peripheral surface to the high pressure side region.

  From the viewpoint of improving the output and / or energy efficiency of the gas turbine, in addition to the adjustment of the ratio of the cooling air 7 discharged to the high-pressure side region and the cooling air 7 discharged to the low-pressure side region, the cooling air hole 6 It is also effective to optimize the relationship between the direction in which the cooling air 7 is discharged from the gas and the rotation direction of the gas turbine rotor blade 1 (the direction along the circumferential direction of the rotor disk and the direction in which the gas turbine rotor blade 1 rotates) It is. Referring again to FIGS. 4A and 4B, out of the total amount of the cooling air 7 supplied to the chip shroud 4, the cooling air 7 having a flow rate higher than 50% has a velocity component in the direction opposite to the rotation direction. It is preferably discharged from the chip shroud 4, and more preferably, the cooling air 7 having a flow rate of 70% or more is preferably discharged so as to have a velocity component in the direction opposite to the rotation direction. When the cooling air 7 is released in such a direction, the work is performed on the gas turbine rotor blade 1 by the reaction, so that the output and / or energy efficiency of the gas turbine can be improved. 4A and 4B, only the cooling air hole 6b out of the plurality of cooling air holes 6 discharges the cooling air 7 so as to have a velocity component in the same direction as the rotation direction, and the other cooling air holes 6 are The cooling air 7 is discharged so as to have a velocity component in the direction opposite to the rotation direction. In such a structure, the flow rate of the cooling air 7 having a flow rate larger than half of the total flow rate of the cooling air hole 6 to the cooling air 7 of the chip shroud 4 or a flow rate of 70% or more is opposite to the rotational direction. Can be released to have.

  In order to further improve the output and / or energy efficiency of the gas turbine, as shown in FIGS. 8A and 8B, the entire amount of the cooling air 7 supplied to the tip shroud 4 is removed from the gas turbine rotor blade 1. It is preferable to discharge from the chip shroud 4 so as to have a velocity component in the direction opposite to the rotation direction. The chip shroud 4 illustrated in FIGS. 8A and 8B has a structure in which the cooling air holes 6b are removed from the chip shroud 4 illustrated in FIGS. 4A and 4B, respectively. In such a structure, the entire amount of the cooling air 7 discharged from the cooling air hole 6 of the tip shroud 4 is discharged so as to have a velocity component in the direction opposite to the rotation direction of the gas turbine rotor blade 1. Thereby, the output and / or energy efficiency of a gas turbine can be improved further.

  In the above-described embodiment, the cooling structure inside the airfoil portion 3 of the gas turbine rotor blade 1 can be variously changed in addition to the cooling structure shown in FIG. FIG. 9 is an example of another cooling structure. In the cooling structure of the airfoil portion 3 in FIG. 9, the core support rib 14 and the inclined turbulator 15 are provided in the cavity 16 inside the airfoil portion 3. The core support rib 14 is a structural member for maintaining the structure of the airfoil 3. The cavity 16 is configured such that the cooling air 7 flows while cooling the inner surface of the airfoil 3 and reaches the tip of the airfoil 3, and the inclined turbulator 15 disturbs the flow of the cooling air 7, The airfoil 3 is effectively cooled.

  When the cooling structure of the airfoil portion 3 is changed, the structure of the cooling air hole 6 can be changed according to the change. For example, when the cooling structure of FIG. 9 is employed, the cooling air hole 6 is configured to communicate with the cavity 16 inside the airfoil 3 as illustrated in FIG. 10.

  FIG. 11 is a plan view showing a structure of a chip shroud 4 according to another embodiment of the present invention, and FIG. 12 is a cross-sectional view taken along the line JJ of FIG. In the structure of the tip shroud 4 in FIGS. 11 and 12, a cavity 8 communicating with the plurality of cooling channels 13 of the airfoil 3 is provided inside the tip shroud 4, and the cooling air holes 6 of the tip shroud 4 are Connected to the cavity 8. The cavity 8 contributes to realizing an appropriate distribution of the cooling air 7. For example, in the structure of FIG. 11, it is possible to supply a large amount of cooling air 7 to the portion (high stress portions X and Y in FIG. 11) of the chip shroud 4 where high thermal stress acts. That is, cooling air 7 from two cooling flow paths 13 of the airfoil portion 3 is supplied from the cavity 8 to the cooling air hole 6 that passes in the vicinity of the high stress portion X. Similarly, cooling air 7 from 1.5 cooling channels 13 is supplied from the cavity 8 to the cooling air holes 6 that pass through the high stress portion Y.

  FIG. 13 is a plan view showing a structure of a tip shroud 4 in still another embodiment of the present invention. For example, as shown in FIG. 4B, in the structure in which the entire amount of the cooling air 7 supplied to the tip shroud 4 is discharged to the high pressure side region, cooling of the portion located in the low pressure side region of the tip shroud 4 is not possible. Although it may be sufficient, the chip shroud 4 of FIG. 13 has a structure for dealing with a problem related to cooling of a portion located in the low pressure side region.

  In the tip shroud 4 of FIG. 13, a part of the cooling air hole 6 (cooling air hole indicated by reference numeral 6 c in FIG. 13) is a position where the cooling air 7 from the airfoil 3 is supplied (in FIG. 13). , Extending to the downstream side of the hot gas from the position of the cooling passage 13 (specifically, extending in a direction having a component in the downstream direction of the hot gas) to reach a specific position in the low-pressure side region, It extends | stretches so that it may reach the opening provided in the high voltage | pressure side area | region from the specific position. In such a structure, even if it is a structure in which a large proportion (most simply, the entire amount) of the cooling air 7 supplied to the chip shroud 4 is discharged to the high pressure side region, a portion located in the low pressure side region is sufficient. Can be cooled to.

  The structure of the cooling air hole 6 of the chip shroud 4 as described above can make the manufacturing process complicated. The cooling air hole 6 of the chip shroud 4 can be formed by electric discharge machining. Electric discharge machining is the most typical method of providing a through hole in a metal structure. However, when the cooling air hole 6 is manufactured by this electric discharge machining, it is difficult to accurately manufacture the cooling air hole 6 that does not penetrate the chip shroud 4 as shown in FIGS. 4A and 4B. There is a case. The bent cooling air holes 6 as shown in FIG. 13 are more difficult to manufacture. Below, the manufacturing process for manufacturing the cooling air hole 6 which has not penetrated and the cooling air hole 6 of the bent shape is described.

  14A and 14B are plan views showing a manufacturing process of the cooling air hole 6 in one embodiment of the present invention. First, as shown in FIG. 14A, a through hole 21 is formed that penetrates the position of the high-pressure side region and the position of the low-pressure side region of the chip shroud 4. The through hole 21 is easily formed by, for example, electric discharge machining. Here, in a subsequent step, the gas is extended from the position where the cooling air 7 from the airfoil 3 is supplied to the downstream side of the high-temperature gas and reaches a specific position in the low-pressure side region. As for the through hole 21 processed into the cooling air hole 6 extending so as to reach the opening provided in the region, a communication part 22 that communicates with the adjacent through hole 21 is formed and connected to the communication part 22. A through-hole 21 is formed in the bottom. The communication part 22 opens to the low pressure side region. When the discharge electrode used for electric discharge machining of the through hole 21 is composed of a plurality of discharge rods and a root portion that supports the discharge rod, such a communication portion 22 extends to the root portion of the discharge electrode. It can be easily formed by inserting it into the chip shroud 4. Thereby, the through hole 21 has openings in both the high-pressure side region and the low-pressure side region.

  Subsequently, as shown in FIG. 14B, unnecessary openings of the through hole 21 and the communication portion 22 are closed, and the manufacture of the cooling air hole 6 is completed. Unnecessary closing of the opening may be performed, for example, by welding the closing plate 23 to the tip shroud 4 or by filling the metal brazing 24 near the opening of the through hole 21 by brazing. At this time, as shown in FIG. 14B, all the openings located in the low pressure side region may be closed, or a part of the openings located in the high pressure side region may be closed. What is important is that the flow rate of the cooling air 7 discharged to the high pressure side region is larger than the flow rate of the cooling air 7 discharged to the low pressure side region, or the total amount of the cooling air 7 supplied to the chip shroud 4 is large. It is to realize a structure that is discharged to the high-pressure side region.

  In the above description, the embodiment in which the cooling air hole 6 is configured as a flow path extending from the cooling flow path 13 (or the cavity 16) of the airfoil 3 has been described. However, the cooling structure of the chip shroud 4 and the chip are described. The structure for discharging the cooling air 7 from the shroud 4 is not limited to this. The flow rate of the cooling air 7 released to the high pressure side region is larger than the flow rate of the cooling air 7 released to the low pressure side region, or the entire amount of the cooling air 7 supplied to the chip shroud 4 is released to the high pressure side region. The structure to be achieved can be realized in various structures. For example, as shown in FIGS. 15 and 16, the present invention is applicable to a chip shroud 4 that employs a cooling structure in which a cavity 30 is provided inside.

  More specifically, in the structure of the tip shroud 4 shown in FIG. 15, an opening 31 communicating with the cavity 30 of the tip shroud 4 is provided in the airfoil 3, and the cooling air 7 passes through the opening 31 to form the cavity 30. Introduced inside. A pin fin 32 is provided in the cavity 30, and the chip shroud 4 is effectively cooled by disturbing the flow of the cooling air 7 by the pin fin 32. The cooling air 7 introduced into the cavity 30 inside the chip shroud 4 is discharged from an opening 33 provided at the end of the chip shroud 4. Here, in the structure of the chip shroud 4 shown in FIG. 15, the opening 33 is provided so that all of the cooling air 7 supplied to the chip shroud 4 is discharged to the high pressure side region. That is, the opening 33 is provided only in the high-pressure side region, and is not provided in the low-pressure side region. In FIG. 15, all the openings 33 are provided in the high pressure side region, but the flow rate of the cooling air 7 released to the high pressure side region may be larger than the flow rate of the cooling air 7 released to the low pressure side region. For example, a part of the openings 33 may be provided in the low pressure side region.

  On the other hand, in the structure of the chip shroud 4 shown in FIG. 16, the pin fin 32 is provided in the cavity 30 of the chip shroud 4, and the opening 33 for discharging the cooling air 7 introduced into the cavity 30 is further provided in the chip shroud 4. It is provided at the end. In addition, in the structure of FIG. 16, a partition wall 34 is formed in the cavity 30 of the chip shroud 4. The partition wall 34 extends from the position where the cooling air 7 from the airfoil portion 3 is supplied (the position of the cooling flow path 13 in FIG. 16) to the downstream side of the high temperature gas (specifically, downstream of the high temperature gas). A flow path 35 extending to reach a specific position in the low-pressure side region and further communicating with the opening 33 provided in the high-pressure side region. Is formed. In the structure of FIG. 16, the cooling air 7 passing through the low pressure side region is ensured, and the problem of cooling of the low pressure side region of the chip shroud 4 can be solved as in the structure of FIG.

  In the embodiment described above, a configuration in which each chip shroud 4 is provided with a single fin 5 is illustrated. However, each chip shroud 4 may be provided with a plurality of fins in the axial direction. FIG. 17 shows a chip shroud 4 provided with three fins 5a to 5c. In this case, the high pressure side region and the low pressure side region are defined by the fin 5c located on the most downstream side of the flow of the high temperature gas. The flow rate of the cooling air 7 discharged to the upstream region (that is, the high-pressure side region) of the high-temperature gas from the fin 5c is changed to the cooling air 7 that is discharged to the region (ie, the low-pressure side region) downstream from the fin 5c. The amount of the flow rate of the cooling air 7 is increased or the entire amount of the cooling air 7 supplied to the chip shroud 4 is discharged to the high pressure side region, so that the operational effect of the present invention can be obtained. In this case, the position where the cooling air 7 is discharged to the high-pressure side region may be any of the regions (1) to (3) in FIG. Here, the region (1) is a region upstream of the fins 5a, the region (2) is a region between the fins 5a and 5b, and the region (3) is a region between the fins 5b and 5c. . The cooling air 7 may be discharged to a plurality of the regions (1) to (3).

  However, from the viewpoint of further improving the output and / or energy efficiency of the gas turbine, the region (1) is most preferable as the position where the cooling air 7 is discharged to the high pressure side region, and then the region (2) is preferable. .

  Although the embodiments of the present invention have been specifically described above, the present invention should not be construed as being limited to the above-described embodiments, and various modifications obvious to those skilled in the art have been made. Can be implemented. In addition, it should be noted that a plurality of the above embodiments may be implemented in combination as long as there is no technical conflict.

1: Gas turbine rotor blade 2: Blade root portion 3: Airfoil portion 4: Tip shroud 5, 5a, 5b, 5c: Fins 6, 6a, 6b, 6c: Cooling air holes 7: Cooling air 8: Cavity 9: Casing 9a : Chip clearance 11: Cavity 12: Pin fin 13: Cooling channel 14: Core support rib 15: Inclined turbulator 16: Cavity 21: Through hole 22: Communication part 23: Closing plate 24: Metal brazing 30: Cavity 31: Opening 32: Pin fin 33: opening 34: partition wall 35: flow path

Claims (13)

A gas turbine rotor blade that operates by receiving high-temperature gas,
An airfoil with a wing surface formed;
A tip shroud having an inner peripheral surface joined to the tip of the airfoil, and an outer peripheral surface facing the inner peripheral surface;
Comprising fins provided on the outer peripheral surface,
The airfoil is configured to supply cooling air to the tip shroud;
The tip shroud is configured to release the cooling air supplied through its internal space;
The flow rate of the cooling air discharged from the tip shroud to the high pressure side region upstream of the hot gas flow from the fin is low pressure side region downstream of the fin hot gas flow from the fin. A gas turbine rotor blade having a flow rate greater than a flow rate of the cooling air discharged from the tip shroud. The gas turbine rotor blade according to claim 1,
The gas turbine rotor blade, wherein a flow rate of the cooling air discharged to the high pressure side region is 70% or more of a total amount of the cooling air supplied to the tip shroud. A gas turbine rotor blade that operates by receiving high-temperature gas,
An airfoil with a wing surface formed;
A tip shroud having an inner peripheral surface joined to the tip of the airfoil, and an outer peripheral surface facing the inner peripheral surface;
Comprising fins provided on the outer peripheral surface,
The airfoil is configured to supply cooling air to the tip shroud;
The tip shroud is configured to release the cooling air supplied through its internal space;
The gas turbine rotor blade, wherein the entire amount of the cooling air supplied to the tip shroud is discharged to a high-pressure side region that is upstream of the flow of the hot gas from the fins. A gas turbine rotor blade according to any one of claims 1 to 3,
Gas discharged from the tip shroud so that cooling air having a flow rate greater than 50% of the total amount of the cooling air supplied to the tip shroud has a velocity component in a direction opposite to the rotation direction of the gas turbine rotor blade. Turbine blade. The gas turbine rotor blade according to claim 4, wherein
A gas turbine in which 70% or more of the cooling air supplied to the chip shroud is discharged from the chip shroud so as to have a velocity component opposite to the rotation direction of the gas turbine rotor blade. Rotor blade. A gas turbine rotor blade according to any one of claims 1 to 3,
A gas turbine rotor blade that is discharged from the tip shroud so that a total amount of the cooling air supplied to the tip shroud has a velocity component in a direction opposite to a rotation direction of the gas turbine rotor blade. A gas turbine rotor blade according to any one of claims 1 to 6,
The airfoil has a cooling passage for supplying the cooling air to the tip shroud,
The tip shroud has a cooling air hole for discharging the cooling air supplied from the cooling passage. A gas turbine rotor blade according to any one of claims 1 to 6,
The airfoil has a cavity for supplying the cooling air to the tip shroud;
The tip shroud has a plurality of cooling air holes for discharging the cooling air supplied from the cavity. A gas turbine rotor blade according to any one of claims 1 to 6,
The airfoil has a plurality of cooling passages for supplying the cooling air to the tip shroud,
The tip shroud includes a cavity that communicates with the plurality of cooling passages, and a cooling air hole that is connected to the cavity and discharges the cooling air. A gas turbine rotor blade according to any one of claims 1 to 9,
The tip shroud extends in a direction having a component in the downstream direction of the hot gas from the position supplied from the airfoil, reaches a specific position, and is provided in the high pressure side region from the specific position. Has a flow channel communicating with the opening,
At least a part of the cooling air supplied to the tip shroud is discharged from the opening provided in the high pressure side region. A manufacturing method for manufacturing the gas turbine rotor blade according to claim 7 or 8,
Producing a through hole penetrating the position of the high pressure side region and the position of the low pressure side region of the chip shroud;
And a step of closing the through hole in the low pressure side region to form the cooling air hole. A manufacturing method for manufacturing the gas turbine rotor blade according to claim 10,
Forming a plurality of through holes penetrating the position of the high-pressure side region and the position of the low-pressure side region of the chip shroud, and a communicating portion that communicates with the through-hole and opens to the low-pressure side region; ,
And a step of closing the communication portion in the low-pressure side region to form the cooling air hole. It is a manufacturing method of Claim 12, Comprising:
The method of manufacturing a gas turbine rotor blade, wherein the through hole and the communication portion are formed by inserting a discharge electrode configured of a plurality of discharge rods and a root portion supporting the discharge rod into the tip shroud.

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