Cooling structure of a turbine blade shroud and manufacturing method therefor

Abstract

A shroud for a turbine blade is provided. The shroud comprises a shroud base body having a first wall with a gas path surface facing a hot gas passage of the turbine and a cooling surface facing away from the hot gas passage, a shroud edge arranged on a circumference of the shroud base body and thus surrounding the shroud base body, wherein the shroud edge has a shroud edge passage arranged therein, and a baffle box arranged such that it faces the cooling surface of the first wall and is spaced from the cooling surface of the first wall. The baffle box comprises a cooling air inlet for introducing cooling air from the shroud edge passage into an interior of the baffle box and an baffle air hole provided to expel the introduced cooling air onto the cooling surface of the first wall in order to cool the cooling surface of the first wall.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a cooling structure of a turbine blade shroud and further relates to a manufacturing method of a cooling structure of a turbine blade shroud. TECHNICAL BACKGROUND

[0002] A gas turbine guide vane and a gas turbine blade are exposed to high-temperature combustion gas. Therefore, the guide vane and the blade are cooled using cooling air. For example, US Patent 9,638,047 (US'047) describes an impact plate that sequentially impact cools a guide vane. Fig. 5 of US'047 describes that a series of separate impingement cavities 12, 13, 21 are sequentially impingement cooled. List of cited publicationsPatent specification

[0003] Patent Document 1: US Patent 9,638,047 OVERVIEW OF THE INVENTIONTechnical Problem

[0004] Recently, gas turbine inlet temperatures have increased; further facilitating the cooling of the first-stage guide vane is therefore desirable. One approach to addressing the above-mentioned problem is to supply cooling air to the first-stage guide vane at a higher pressure and lower temperature (compared to conventional technology). The inventors' research has shown that when the higher-pressure, lower-temperature cooling air is used to cool the first-stage guide vane, it is possible to reuse the cooling air to cool other elements or components of the first-stage guide vane, even after the cooling air has been used to cool an airfoil or shroud edge. However, in conventional technology, the efficiency of using the cooling air is limited.

[0005] It is desirable to provide a cooling method or structure of a gas turbine vane that enables higher efficiency in the use of cooling air. Solution to the problem

[0006] According to a first aspect of the present disclosure, a shroud of a turbine blade is provided, comprising: a shroud base body having a first wall with a gas path surface facing a hot gas passage of the turbine and a cooling surface facing away from the hot gas passage; a shroud edge arranged on a periphery of the shroud base body and thus surrounding the shroud base body, the shroud edge having a shroud edge passage arranged therein; and an impact box arranged to face the cooling surface of the first wall and to be spaced from the cooling surface of the first wall.The baffle box comprises a cooling air inlet for introducing cooling air from the shroud edge passage into an interior of the baffle box and an impact air hole which is provided for ejecting the introduced cooling air onto the cooling surface of the first wall in order to cool the cooling surface of the first wall.

[0007] Since the shroud has the impact box, the above-described feature can provide a shroud of a turbine blade that enables easy manufacture and assembly thereof, while improving cooling efficiency by preventing cooling air leakage.

[0008] According to a second aspect of the present disclosure, a method for producing a shroud of a turbine blade is provided, the shroud comprising: a shroud base body having a first wall with a gas path surface facing a hot gas passage of the turbine and a cooling surface facing away from the hot gas passage, and a shroud edge arranged on a circumference of the shroud base body and thus surrounding the shroud base body, the shroud edge having a shroud edge passage arranged therein.The method comprises: disposing a baffle box such that it faces the cooling surface of the first wall and is spaced apart from the cooling surface of the first wall; wherein the baffle box has a cooling air inlet for introducing cooling air from the shroud edge passage into an interior of the baffle box and an impingement air hole configured to expel the introduced cooling air onto the cooling surface of the first wall to cool the cooling surface of the first wall.

[0009] Since the baffle box is arranged on the shroud, the above-described feature can provide a shroud of a turbine blade that enables easy manufacture and assembly thereof, while improving cooling efficiency by preventing cooling air leakage.

[0010] The advantages of the disclosure will become apparent from the following description taken in conjunction with the accompanying drawings. SHORT DESCRIPTION OF THE FIGURES [ Fig. 1] Schematic sectional view of a gas turbine in an embodiment according to the present disclosure. [ Fig. 2] Perspective view of a guide vane in a first embodiment. [ Fig. 3] Sectional view along line III-III of Fig. 2. [ Fig. 4] Enlarged partial view of the guide vane. [ Fig. 5] Perspective view of a part of a guide vane according to the first embodiment. [ Fig. 6] Perspective view of a part of a guide vane according to another embodiment. [ Fig. 7] Flowchart illustrating a cooling method of the guide vane according to the first embodiment. [ Fig. 8] Flowchart illustrating a cooling method of the guide vane according to the second embodiment. [ Fig. 9] Schematic representation of cooling steps according to the second embodiment. [ Fig. 10] Flowchart illustrating a cooling method of the guide vane according to a third embodiment. [ Fig. 11] Schematic sectional view of a guide vane according to a fourth embodiment. [ Fig. 12A] Schematic sectional view of a guide vane according to a fifth embodiment. [ Fig. 12B] Schematic sectional view of a guide vane according to the fifth embodiment. [ Fig. 13A] Schematic sectional view of a guide vane according to a sixth embodiment. [ Fig. 13B] Schematic sectional view of a guide vane according to the sixth embodiment. [ Fig. 14] Perspective view of a seventh embodiment. [ Fig. 15] Schematic view of the seventh embodiment. [ Fig. 16A] Perspective view of a guide vane according to the seventh embodiment. [ Fig. 16B] Perspective view of a modification of the seventh embodiment. [ Fig. 17] Flowchart illustrating a manufacturing process of a shroud of a turbine blade. [ Fig. 18] Perspective view of a guide vane according to an eighth embodiment. [ Fig. 19] Schematic sectional view of a guide vane according to the eighth embodiment. [ Fig. 20] Enlarged partial view of Fig. 19. [ Fig. 21] Enlarged partial view of the impact box. [ Fig. 22] Sectional view along the line XXII-XXII of Fig. 20. [ Fig. 23A] Schematic sectional view of a guide vane according to the eighth embodiment. [ Fig. 23B] Schematic sectional view of a guide vane according to the eighth embodiment. [ Fig. 24] Flowchart illustrating a manufacturing process for a turbine blade shroud. [ Fig. 25] Schematic sectional view of a guide vane according to the eighth embodiment. [ Fig. 26] Schematic cross-sectional view of a guide vane describing the principle of the eighth embodiment. [ Fig. 27] Schematic sectional view according to a ninth embodiment. [ Fig. 28] Schematic view from below according to the ninth embodiment. [ Fig. 29] Schematic sectional view of a modification of the ninth embodiment. DESCRIPTION OF THE EMBODIMENTS

[0011] A preferred embodiment of the present disclosure will now be described in detail with reference to the drawings. Fig. 1 is a schematic sectional view of a gas turbine in one embodiment according to the present disclosure. As in Fig. 1, a gas turbine 10 according to this embodiment includes a turbine 20 driven by combustion gas generated by a combustor 30. The turbine 20 includes a rotor shaft 24, a turbine rotor 26 rotating about an axis Ar, a turbine casing 22 covering the turbine rotor 26, and a plurality of guide vane stages 28.

[0012] Fig. 2 is a schematic illustration of a gas turbine vane according to an embodiment of the present disclosure. Fig. 2 is a perspective view of a guide vane in a first embodiment. Fig. 3 is a sectional view along the line III-III of Fig. 2. Fig. 4 is an enlarged partial view of the guide vane. As in Fig. 2, a stationary vane 50 includes a blade body (airfoil) 51 extending in a radial direction of a gas turbine, an inner shroud 60 disposed on the radially inner side of the blade body 51, and an outer shroud 70 disposed on the radially outer side of the blade body 51. The blade body 51 is disposed in a combustion gas flow passage (hot gas passage) through which the combustion gas flows. Generally, an annular combustion gas flow passage is defined on its radially inner side by the inner shroud 60 and on its radially outer side by the outer shroud 70. The inner shroud 60 and the outer shroud 70 are plate-shaped members that define a part of the combustion gas flow passage.

[0013] As in Fig. 2, one end of the blade body 51 on the upstream side has a leading edge 52, and one end of the blade body 51 on the downstream side has a trailing edge 53. Of the surfaces of the blade body 51, a convex surface is a suction-side surface 54 (negative pressure surface), and a concave surface is a pressure-side surface 55 (pressure surface). For convenience, in the following descriptions, the pressure side (pressure surface side) of the blade body 51 and the suction side (negative pressure surface side) of the blade body 51 are referred to as the pressure side and the suction side, respectively.

[0014] The inner casing 60 and the outer casing 70 have essentially the same structure. Therefore, the outer casing 70 will be described primarily below.

[0015] As in Fig. 2 and Fig. 3, the outer shroud 70 is a plate-shaped shroud member comprising a shroud base body 72, a shroud edge 74 disposed on a periphery of the shroud base body 72, and a peripheral wall 76 extending along the shroud edge 74 and projecting from the shroud base body 72 toward the radially outer side of the gas turbine.

[0016] The outer shell 70 includes an upstream surface, which is a surface on the upstream side, a downstream surface, which is a surface on the downstream side, a pressure side surface, which is a surface on the pressure side, and a suction side surface, which is a surface on the suction side. The outer shell 70 has a gas path surface 78 facing the radially inner side and facing the hot gas passage. The upstream surface and the downstream surface are substantially parallel to each other. The pressure side surface and the suction side surface are substantially parallel to each other. Thus, the outer shell 70 has a substantially parallelogram shape when viewed from the radial direction, as shown in Fig. 3 shown.

[0017] The shroud edge 74 is a rim- or lip-shaped structure that protrudes from the shroud base body 72. The shroud edge 74 includes an upstream shroud edge 74 L , which is arranged on the upstream side of the outer casing 70, a downstream casing edge 74 T , which is arranged on the downstream side of the outer casing 70, a suction-side casing edge 74 N , which is arranged on the suction side of the outer casing 70, and a pressure-side casing edge 74 P , which is arranged on the pressure side of the outer casing 70. For example, as in Fig. 3, the upstream shroud edge 74 L , the drain-side casing edge 74 T , the suction-side casing edge 74 N and the pressure-side casing edge 74 Parranged on a circumference of the casing base body 72 so that they completely surround the casing base body 72.

[0018] The upstream shroud edge 74 L has an upstream shroud edge passage 75 L The drain-side casing edge 74 T has a drain-side casing edge passage 75 T The suction-side casing edge 74 N has a suction-side casing edge passage 75 N The pressure-side casing edge 74 P has a pressure-side casing edge passage 75 P on.

[0019] In this embodiment, the upstream shroud edge passage 75 L at one end with the suction-side casing edge passage 75 N and at its other end with the pressure-side casing edge passage 75 Pin connection. The outlet-side casing edge passage 75 T stands at one end with the suction-side casing edge passage 75 N and at its other end with the pressure-side casing edge passage 75 P in connection. As in the Fig. 2, Fig. 3 and Fig. 4, the upstream shroud edge passage 75 L a casing edge passage inlet 171. The outlet-side casing edge passage 75 T has a shroud edge passage outlet 172. A portion of the cooling air passing through the shroud edge passage inlet 171 into the upstream shroud edge passage 75 L flows through the suction-side casing edge passage 75 N and the pressure-side casing edge passage 75 P , then it flows through the outlet-side casing edge passage 75 T and then flows out of the shroud edge passage outlet 172. As in Fig. 3, the sheath edge passages 75 L , 75 T , 75 P , 75 N Turbulators 175. The turbulator 175 may be a rib disposed on an inner surface of the shroud edge passages. To improve cooling of the shroud edge, the turbulator 175 may be disposed on a bottom surface of the passage defining a radially inner side of the passage. Here, the bottom surface of the passage may extend substantially parallel to the radially inner wall 81. The turbulator 175 may also be disposed on a side surface of the passage defining a lateral outer side of the passage.

[0020] In the present embodiment, the shroud edge passage inlet 171 is arranged at the upstream shroud edge passage 75L, and the shroud edge passage outlet 172 is arranged at the downstream shroud edge passage 75T. However, the structure of the guide vane is not limited to this embodiment. The shroud edge passage inlet 171 may be arranged at another shroud edge passage, such as the suction-side shroud edge passage 75. N , the pressure-side casing edge passage 75 P or the downstream casing edge passage 75 T , be arranged. The shroud edge passage outlet 172 may be arranged at another shroud edge passage, such as the suction side shroud edge passage 75 N , the pressure-side casing edge passage 75 P or the upstream shroud edge passage 75 LAlternatively, multiple shroud edge passage inlets 171 may be arranged on one or more shroud edge passages 75 L , 75 T , 75 N , 75 P In addition, multiple shroud edge passage outlets 172 may be arranged at one or more shroud edge passages 75 L , 75 T , 75 N , 75 P be arranged.

[0021] The shroud base body 72 comprises a radially inner wall 81 and a radially outer wall 82 opposite the radially inner wall 81. The shroud base body 72 contains a cavity S in its interior between the radially inner wall 81 and the radially outer wall 82. The radially inner surface of the inner wall 81 forms the gas path surface 78 of the outer shroud 70. The radially inner wall 81 forms part of the shroud base body 72. The radially inner wall 81 can extend continuously outward to form part of the shroud edge 74. Fig. 2 describes - as an embodiment - that the radially inner wall 81 extends continuously outwards and thus forms part of the downstream casing edge 74 TThe shroud main body 72 has a baffle plate 73 that divides the space S of the outer shroud 70 into an outer region on the radially outer side and an inner region (cavity), which is a region on the radially inner side. The outer region is connected to the shroud edge passage outlet 172, so that part of the cooling air from the downstream shroud edge passage 75 T flows into the outer region. The inner region is defined between the baffle plate 73 and the radially inner wall 81 of the outer casing 70.

[0022] A plurality of air holes 79 are arranged in the baffle plate 73, which extend radially through the baffle plate 73. A portion of the cooling air present in the outer region flows through the air holes 79 of the baffle plate 73 into the inner cavity. For impingement cooling of the radially outer surface of the radially inner wall 81, the cooling air is expelled from the air holes 79 toward a radially outer surface of the radially inner wall 81 and then blown out through the radially outer wall 82 toward the outside of the outer wall 82.For impingement cooling of the radially outer surface of the radially inner wall 81, the cooling air is expelled, for example, from the air holes 79 toward a radially outer surface of the radially inner wall 81 and then blown out through a passage connecting the inner region (cavity) of the hollow space (S) and an outer space located on the opposite side of the radially outer wall 82 from the cavity (S). Such a passage may be isolated from the outer region of the hollow space (S). More specifically, in this embodiment, the cooling air is blown out through a hole of an outlet duct 83. The outlet duct 83 is provided to penetrate the radially outer wall 82 and the baffle plate 73, thus connecting the inner region and the outer space.

[0023] The blade body 51 comprises a plurality of air channels 141, 142, 143. More specifically, the interior of the blade body 51 is separated by radially extending partition walls 51 P divided into the plurality of air channels 141, 142, 143. A plurality of inserts 151, 152, 153 are inserted into the respective air channels 141, 142, 143. The plurality of inserts 151, 152, 153, which have respective radially extending inner air channels 161, 162, 163, extend radially from the outer shroud 70 through the blade body 51 to the inner shroud 60. Each of the inserts 151, 152, 153 is formed continuously from the outer shroud 70 through the blade body 51 to the inner shroud 60. Each of the inner air channels 161, 162, 163 has an air inlet 58 open to the interior of an intake port 56.

[0024] Each of the inserts 151, 152, 153 has a plurality of openings (through holes) 59 that communicate with the respective inner air channels 161, 162, 163. For impingement cooling of the inner surface of the blade 51, a portion of the cooling air supplied to the inner air channels 161, 162, 163 of the inserts 151, 152, 153 is expelled from the plurality of openings 59 toward an inner surface of the blade body 51. The plurality of air channels 141, 142, 143 have respective outer air channels defined between the inserts 151, 152, 153 and the inner surface of the blade body 51. The part of the cooling air expelled through the openings 59 is guided through the outer air ducts and flows through them in a radially outward direction, in a radially inward direction or both in a radially outward direction and in a radially outward direction through the outer air ducts. Fig. 3 shows, by way of example, the outer air channel 57 between the side surface of the insert 151 and the inner surface of the upstream region of the blade body 51.

[0025] The intake manifold 56 and the exhaust line 83 are connected to a forced air cooling system in which cooling air extracted from the interior of a combustor casing is cooled by an external cooling device (not shown) and then compressed by an external compressor (not shown). The compressed air is used for cooling and then returned to the interior of the combustor casing. In the foregoing description, the air cooling system is applied to the present embodiment. However, the present vane is not limited to such an embodiment. The present disclosure may be applied to other types of cooling systems. For example, the intake manifold 56 and the exhaust line 83 may be connected to a closed-cycle steam cooling system or a closed-cycle air cooling system.The compressed air used for cooling is supplied to the intake manifold and directly supplied first to the air inlet 58 without passing through the shroud base 72 or the shroud edge 74. In other words, the cooling air is first used to cool the blade 51 before being used to cool the shroud base 72 or the shroud edge 74.

[0026] In the present embodiment, the air duct 141 is an upstream air duct positioned at an upstream end of the blade body 51. For example, in the insert 151 configured as an upstream insert, a portion of the cooling air supplied to the inner air duct 161 through the air inlet 58 is expelled through the openings 59 toward the inner surface of the upstream region of the blade 51 and then guided to flow radially outward through the outer air duct 57. The outer air duct 57, configured as a space between the insert 151 and the inner surface of the upstream region of the blade body 51, communicates with the shroud edge passage inlet 171 of the upstream shroud edge passage 75. LThe portion of the cooling air discharged toward the inner surface of the upstream region of the blade 51 flows through the outer air duct 57 connected to the shroud edge passage inlet 171 into the shroud edge passage inlet 171 of the upstream shroud edge passage 75 L .

[0027] Fig. 5 is a perspective view of a part of a guide vane according to the first embodiment. In the present embodiment, the air duct 142 is a middle air duct positioned on a downstream side of the upstream air duct 141 and further positioned between the upstream air duct 141 and a downstream air duct 143 (described below). For example, in the insert 152 formed as a middle insert, a part of the cooling air supplied through the air inlet 58 to the inner air duct 162 is expelled through the openings 59 toward the inner surface of the central region of the airfoil 51 and then guided to flow radially inward through the corresponding outer air duct toward the inner shroud 60, and then, as shown in Fig. 5, in the (on a downstream casing edge 64 Tarranged) shroud edge passage inlet 181 of the inner shroud 60. The cooling air then flows through the shroud edge passage 65 of the inner shroud 60 to cool the shroud edge 64 of the inner shroud 60, and then flows through the (at an upstream shroud edge 64 L arranged) shroud edge passage outlet 182 of the inner shroud 60 into the shroud main body 62 of the inner shroud 60. Similar to the outer shroud 70, the cooling air is expelled from the air holes of the baffle plate 63 to cool the radially outer wall of the inner shroud 60, which includes a gas path surface facing the radially outer side and the hot gas passage.

[0028] In the present embodiment, a part of the cooling air discharged from the upstream inner air passage 161 toward the inner surface of the upstream portion of the airfoil 51 is guided to flow radially outward through the outer air passage 57 toward the outer shroud 70. Further, a part of the cooling air discharged from the center inner air passage 162 toward the inner surface of the center portion of the airfoil 51 is guided to flow radially inward through the outer air passage 57 toward the inner shroud 60. However, the structure of the guide vane is not limited to this embodiment.A portion of the cooling air discharged from the upstream inner air duct 161 toward the inner surface of the upstream region of the airfoil 51 may be directed to flow radially inward through the outer air duct 57 toward the inner shroud 60. Furthermore, a portion of the cooling air discharged from the central inner air duct 162 toward the inner surface of the central region of the airfoil 51 may be directed to flow radially outward through the outer air duct 57 toward the outer shroud 70. Such a modification will be described in more detail below as another embodiment.

[0029] In some embodiments of this disclosure, as in Fig. 2, the air duct 143 is a downstream air duct positioned at a downstream end of the blade body 51. The downstream air duct 143 further includes an airfoil cooling structure 154 on a downstream side of the insert 153. The airfoil cooling structure 154 has a passage in which a plurality of pin fins 164 are disposed. For example, in the insert 153 configured as a downstream insert, a portion of the cooling air supplied to the inner air duct (the downstream inner air duct) 163 through the air inlet 58 is expelled through the openings 59 toward the inner surface of a downstream portion of the blade 51 and then guided to flow to the airfoil cooling structure 154. Part of the cooling air flows through the passage with the pin fins 164 and is then blown out to the hot gas passage at the trailing edge 53 of the blade 51.

[0030] Fig. 6 is a perspective view of a portion of a guide vane according to another embodiment. As in Fig. 6, in this embodiment, the shroud edge passage inlet 181 of the inner shroud 60 is located at the upstream shroud edge 64 L In addition, the casing edge passage outlet 182 of the inner casing 60 is arranged at the downstream casing edge 64 T Furthermore, in this embodiment, the casing edge passage inlet 171 of the outer casing 70 is arranged at the downstream casing edge 74 T In addition, the shroud edge passage outlet 172 of the outer shroud 70 is arranged at the upstream shroud edge 74 LIn this embodiment, in the insert 151, which is designed as an upstream insert, a part of the cooling air supplied through the air inlet 58 to the inner air duct 161 is expelled through the openings 59 towards the inner surface of the upstream region of the blade 51 and then guided so that it flows through the outer air duct 57 in the radial direction inwards to the inner shroud 60, then it flows, as in Fig. 6, in the (on the upstream side of the casing edge 64 L arranged) shell edge passage inlet 181 of the inner shell 60. The cooling air then flows through the shell edge passage 65 of the inner shell 60 to cool the shell edge 64 of the inner shell 60, and then flows through the (on the downstream shell edge 64 Tarranged) shroud edge passage outlet 182 of the inner shroud 60 into the shroud main body 62 of the inner shroud 60. Furthermore, in this embodiment, in the insert 152 designed as a middle insert, a part of the cooling air supplied to the inner air duct 162 through the air inlet 58 is expelled through the openings 59 towards the inner surface of the middle region of the blade 51 and then guided such that it flows through the outer air duct in the radial direction outwards to the outer shroud 70 and that it then flows into the (at the outlet-side shroud edge 74 T arranged) shroud edge passage inlet 171 of the outer shroud 70. The cooling air then flows through the shroud edge passage 75 of the outer shroud 70 to cool the shroud edge 74 of the outer shroud 70, and then flows through the (at the upstream shroud edge 74 Larranged) casing edge passage outlet 172 of the outer casing 70 into the casing main body 72 of the outer casing 70.

[0031] Next, a cooling method of a guide vane according to the first embodiment will be described. Fig. 7 is a flowchart illustrating a cooling method of the guide vane according to the first embodiment. As shown in Fig. 7, in a step S102, a portion of the cooling air is caused to flow into the upstream air duct 141 to cool the upstream air duct 141. The cooling air is expelled from the upstream inner air duct 161 through the openings 59 of the insert 151 toward the inner surface of the upstream region of the airfoil 51 and is guided either radially outwardly or radially inwardly through the outer air duct 57 to the outer shroud 70 or the inner shroud 60 to cool the outer shroud 70 or the inner shroud 60.

[0032] In a step S104, a portion of the cooling air is caused to flow into the central air duct 142 to cool the central air duct 142. The cooling air is expelled from the central inner air duct 162 through the openings 59 of the insert 152 toward the inner surface of the central region of the airfoil 51 and guided through the outer air duct 57 in the radially outward direction and in the radially inward direction to the outer shroud 70 and the inner shroud 60, respectively, to cool the outer shroud 70 and the inner shroud 60, respectively.

[0033] Next, a cooling method of a guide vane according to the second embodiment will be described. Fig. 8 is a flowchart illustrating a cooling method of the stationary vane according to the second embodiment. This method will be described using the air duct 141 and the outer shroud 70 as examples. Fig. 9 is a schematic representation of cooling steps according to the second embodiment. As in Fig. 8 and Fig. As shown in Figure 9(a), in a step S202, a portion of the cooling air is caused to flow through the air inlet 58 into the inner air passage 161 of the insert 151. The cooling air is then expelled through the openings 59 toward the inner surface of the upstream region of the airfoil 51 to cool the airfoil 51 and subsequently flows radially outward through the outer air passage 57. In some of these embodiments, the portion of the cooling air caused to flow into the inner air passage 161 may be introduced from the forced air cooling system.

[0034] As in Fig. As shown in Fig. 9(b), in a step S204, the cooling air is caused to flow into the shroud edge passage 75 through the shroud edge passage inlet 171. The cooling air flows along and through the shroud edge passage 75 to cool the shroud edge passage 75.

[0035] As in Fig. 9(c), in a step S206, the cooling air flows into the outer region of the shroud main body 72 and is ejected through the air holes 79 toward the radially outer surface of the radially inner wall 81 for impingement cooling of the radially outer surface of the radially inner wall 81 to cool the shroud main body 72.

[0036] Next, a cooling method of a guide vane according to a third embodiment will be described. Fig. 10 is a flowchart illustrating a cooling method of the guide vane according to a third embodiment. As in Fig. 10, in a step S302, a portion of the cooling air is caused to flow through the air inlet into the inner air duct of the insert in at least one of the air ducts. The cooling air is then expelled through the openings toward the inner surface of the upstream region of the airfoil to cool the airfoil and subsequently flows radially outward through the outer air duct. In some of these embodiments, the portion of the cooling air caused to flow into the inner air duct may be introduced from the forced air cooling system.

[0037] In a step S304, the cooling air is caused to flow into the outer region of the casing main body and to be expelled through the air holes in the direction of the radially outer surface of the radially inner wall for impingement cooling of the radially outer surface of the radially inner wall in order to cool the casing main body.

[0038] In a step S306, the cooling air is caused to flow through the shroud edge passage inlet into the shroud edge passage. The cooling air flows along and through the shroud edge passage to cool the shroud edge. In some embodiments, the cooling air may be recirculated to the forced air cooling system through the shroud edge passage outlet.

[0039] Next, a fourth embodiment of the present application will now be described. Fig. 11 is a schematic sectional view of a guide vane according to the fourth embodiment. As in Fig. 11, in the fourth embodiment, several blades 51 (in this embodiment, two blades) are separated from the shroud edge passages 75 L , 75 T , 75 N , 75 P Unlike in the first embodiment ( Fig. 3) are located at the upstream shroud edge passage 75 Ltwo casing edge passage inlets 171 are arranged.

[0040] The respective outer air ducts, which are formed as a space between the insert 151 and the inner surface of the upstream region of the two blades 51, are connected to the respective shroud edge passage inlets 171 of the upstream shroud edge passage 75 L through the respective air passages arranged in an outer end of the respective outer air channels of the respective blades 51. The cooling air flows through the respective shroud edge passage inlets 171 into the upstream shroud edge passage 75 L , flows through the suction-side casing edge passage 75 N or the pressure-side casing edge passage 75 P and then flows through the shroud edge passage outlet 172 into the outer region of the shroud base body 72.

[0041] In the embodiments described above, the blade body (airfoil) includes three air channels 141, 142, 143. However, the number of air channels included in the blade body (airfoil) is not limited to three. The blade body (airfoil) may have a different number of air channels, such as two, four, five, or more. In such a modified embodiment, each air channel may be connected to the outer shroud or the inner shroud.

[0042] A fifth embodiment of the present application is described below by way of example. Fig. 12A and Fig. 12B are schematic sectional views of a guide vane according to the fifth embodiment. As shown in Fig. 12A and Fig. As shown in Figure 12B, the blade body (airfoil) in the fifth embodiment includes air ducts 191, 192, 193, 194, and 195 arranged in this order from an upstream end to a downstream end of the blade body (airfoil) with respect to the hot gas flow in the turbine. The air ducts 191, 192, 193, 194, and 195 each include an insert and an inner air duct (not shown). As shown in Fig. 12A, the first air duct 191 and the second air duct 192 are connected to the upstream casing edge 74 L arranged casing edge passage inlet 171 of the outer casing 70. In addition, as shown in Fig. 12B, the third air duct 193 and the fourth air duct 194 with the casing edge 64 on the outlet side T arranged casing edge passage inlet 181 of the inner casing 60.

[0043] In the present embodiment, a portion of the cooling air introduced into the first air duct 191 flows in the first air duct 191 and is discharged from a first inner air duct through the openings 59 of a first insert toward the inner surface of the upstream region of the airfoil 51; then, it is guided to flow radially outward through the outer air duct 57 toward the outer shroud 70. Similarly, a portion of the cooling air discharged from a second inner air duct of the second air duct 192 through the openings 59 of a second insert toward the inner surface of the central region of the airfoil 51 is guided to flow radially outward through the corresponding outer air duct 57 toward the outer shroud 70. Thereafter, the cooling air is guided into the shroud edge passage inlet 171 of the outer shroud 70.

[0044] In the present embodiment, a portion of the cooling air discharged from a third inner air passage of the third air passage 193 through the openings 59 of a third insert toward the inner surface of the center region of the airfoil 51 is guided to flow radially inward toward the inner shroud 60 through the corresponding outer air passage 57. Further, a portion of the cooling air discharged from a fourth inner air passage of the fourth air passage 194 through the openings 59 of a fourth insert toward the inner surface of the center region of the airfoil 51 is guided to flow radially inward toward the inner shroud 60 through the corresponding outer air passage 57. Thereafter, the cooling air is introduced into the shroud edge passage inlet 181 of the inner shroud 60.

[0045] The fifth air duct 195 is a downstream air duct positioned at a downstream end of the blade body 51. As described above, in the fifth air duct 195, a portion of the cooling air supplied to a fifth inner air duct through the air inlet 58 is expelled through the openings 59 toward the inner surface of a downstream portion of the blade 51 and then guided to flow to the blade cooling structure 154. A portion of the cooling air flows through the pin fin passage 164 and is then discharged to the hot gas passage at the downstream edge 53 of the blade 51.

[0046] The structure of the guide vane is not limited to this embodiment. As an alternative embodiment, the shroud edge passage inlet 171 of the outer shroud 70 may be located at the downstream shroud edge 74. Tbe arranged and the shroud edge passage outlet 172 of the outer shroud 70 can be arranged at the upstream shroud edge 74 L In addition, the shroud edge passage inlet 181 of the inner shroud 60 can be arranged at the upstream shroud edge 64 L be arranged, wherein the casing edge passage outlet 182 of the inner casing 60 is located at the downstream casing edge 64 T In this embodiment, the first air duct 191 and the second air duct 192 are connected to the upstream casing edge 64 L arranged casing edge passage inlet 181 of the inner casing 60. Furthermore, the third air channel 193 and the fourth air channel 194 are connected to the outlet-side casing edge 74 T arranged casing edge passage inlet 171 of the outer casing 70.

[0047] Next, a sixth embodiment of the present application will now be described. Fig. 13A and Fig. 13B are schematic sectional views of a guide vane according to the sixth embodiment. In this embodiment, the outer shroud 70 comprises: two shroud edge passage inlets (one upstream shroud edge passage inlet 171 L and a downstream casing edge passage inlet 171 T ) and two shroud edge passage outlets (one pressure-side shroud edge passage outlet 172 P and a suction-side casing edge passage outlet 172 N ). The upstream shroud edge passage inlet 171 L is on the upstream casing edge 74 L arranged. The outlet-side casing edge passage inlet 171 T is on the drain-side casing edge 74 Tarranged. The pressure-side casing edge passage outlet 172 P is on the pressure-side casing edge 74 P arranged. The suction-side casing edge passage outlet 172 N is on the suction side casing edge 74 N The air ducts 191, 192, 193, 194, and 195 each have an insert and an inner air duct (not shown).

[0048] In this embodiment, the inner shroud 60 has two shroud edge passage inlets (an upstream shroud edge passage inlet 181 L and a downstream casing edge passage inlet 181 T ) and two shroud edge passage outlets (one pressure-side shroud edge passage outlet 182 P and a suction-side casing edge passage outlet 182 N ). The upstream shroud edge passage inlet 181 L is on the upstream shroud edge 64 Larranged. The outlet-side casing edge passage inlet 181 T is on the drain-side casing edge 64 T arranged. The pressure-side casing edge passage outlet 182 P is on the pressure-side casing edge 64 P arranged. The suction-side casing edge passage outlet 182 N is on the suction side casing edge 64 N arranged.

[0049] As in Fig. 13A, the first air duct 191 is connected to the upstream casing edge 74 L arranged casing edge passage inlet 171 L the outer casing 70. And the fourth air duct 194 is connected to the outlet-side casing edge 74 T arranged casing edge passage inlet 171 T the outer casing 70. As in Fig. 13B, the second air duct 192 is connected to the upstream casing edge 64 Larranged casing edge passage inlet 181 L the inner casing 60. The third air duct 193 is connected to the outlet-side casing edge 64 T arranged casing edge passage inlet 181 T the inner casing 60.

[0050] In this embodiment, for example, a portion of the cooling air supplied to the first air duct 191 is expelled from a first inner air duct through the openings 59 of a first insert toward the inner surface of the upstream region of the blade 51 and then guided to flow through the corresponding outer air duct in the radial direction outward to the outer shroud 70; subsequently, as shown in Fig. 13A, into the upstream shroud edge passage inlet 171 L . The cooling air then flows along the upstream shroud edge passage 75 L. The cooling air then flows along the pressure-side shroud edge passage 75 P , then flows out of the pressure-side shroud edge passage outlet 172 P out, flows further along the suction-side casing edge passage 75 N and then flows out of the suction-side shroud edge passage outlet 172 N In this embodiment, for example, a portion of the cooling air supplied to the fourth air duct 194 is expelled from a fourth inner air duct through the openings 59 of a fourth insert toward the inner surface of the central region of the blade 51 and then guided to flow radially outward through the corresponding outer air duct to the outer shroud 70; subsequently, as shown in Fig. 13A, into the downstream casing edge passage inlet 171 T . The cooling air then flows along the outlet side casing edge passage 75T . The cooling air then flows along the pressure-side shroud edge passage 75 P , then flows out of the pressure-side shroud edge passage outlet 172 P out, flows further along the suction-side casing edge passage 75 N and then flows out of the suction-side shroud edge passage outlet 172 N out of here.

[0051] In this embodiment, for example, a portion of the cooling air supplied to the second air duct 192 is expelled from a second inner air duct through the openings 59 of a second insert toward the inner surface of the central region of the blade 51 and then guided to flow through the corresponding outer air duct in a radial direction inward toward the inner shroud 60; subsequently, as shown in Fig. 13B, into the upstream shroud edge passage inlet 181 L. The cooling air then flows along the upstream shroud edge passage 65 L . The cooling air then flows along the pressure-side shroud edge passage 65 P , then flows out of the pressure-side shroud edge passage outlet 182 P out, flows further along the suction-side casing edge passage 65 N and then flows out of the pressure-side shroud edge passage outlet 182 N In this embodiment, for example, a portion of the cooling air supplied to the third air duct 193 is expelled from a third inner air duct through the openings 59 of a third insert toward the inner surface of the central region of the blade 51 and then guided to flow radially inward through the corresponding outer air duct to the inner shroud 60; subsequently, as shown in Fig. 13B, into the downstream casing edge passage inlet 181T . The cooling air then flows along the downstream casing edge passage 65 T . The cooling air then flows along the pressure-side shroud edge passage 65 P , then flows out of the pressure-side shroud edge passage outlet 182 P out, flows further along the suction-side casing edge passage 65 N and then flows out of the pressure-side shroud edge passage outlet 182 N out of here.

[0052] The fifth air duct 195 is a downstream air duct positioned at a downstream end of the blade body 51. As described above, in the fifth air duct 195, a portion of the cooling air supplied to a fifth inner air duct through the air inlet 58 is expelled through the openings 59 toward the inner surface of a downstream portion of the blade 51 and then guided to flow to the blade cooling structure 154. A portion of the cooling air flows through the pin fin passage 164 and is then discharged to the hot gas passage at the downstream edge 53 of the blade 51.

[0053] The structure of the guide vane is not limited to this embodiment. As an alternative embodiment, the first air duct 191 may be connected to the shroud edge passage inlet 181 arranged at the upstream shroud edge 64L. Lthe inner casing 60. Furthermore, the fourth air duct 194 can be connected to the outlet-side casing edge 64 T arranged shroud edge passage inlet 181T of the inner shroud 60. Furthermore, the second air duct 192 can be connected to the shroud edge 74 L arranged casing edge passage inlet 171 L the outer casing 70. The third air duct 193 is connected to the outlet-side casing edge 74 T arranged casing edge passage inlet 171 T the outer casing 70.

[0054] Next, a seventh embodiment of the present application will now be described. Fig. 14 is a perspective view of the seventh embodiment. Fig. 15 is a schematic view of the seventh embodiment. Fig. Fig. 16A is a perspective view of a guide vane according to the seventh embodiment. This embodiment will be described with exemplary use of the outer shroud 70. As shown in Fig. 16A, the outer casing base body 72 has a baffle box 300. As shown in Fig. As shown in Figure 15, the impact box 300 is inserted into a cavity CA formed in the shroud base body 72. The cavity CA is a space surrounded by the shroud edge 74 and the radially inner wall 81. One or more spacers 320 are arranged in the cavity CA.

[0055] As in Fig. 14, the baffle box 300 is a box-shaped structure having a hollow chamber therein. The baffle box 300 includes a front wall 302, a rear wall 304, and a circumferential side wall 306. The baffle box 300 further includes a box air inlet 308 in the circumferential side wall 306. The box air inlet 308 is connected to the shroud edge passage outlet 172 to introduce cooling air into the interior of the hollow chamber. When attached to the shroud base body 72, the front wall 302 forms the radially outer wall 82, and the rear wall 304 forms the baffle plate 73. Thus, the rear wall 304 includes a plurality of air holes 79.

[0056] The front wall 302, the rear wall 304 and the circumferential side wall 306 are connected to each other so that an airtight chamber is arranged within the impact box 300, which chamber is different from the area of ​​the box air inlet 308 and the air holes 79.

[0057] Fig. 16A shows a state in which the impact box 300 is installed in and secured to the outer casing 70. The impact box 300 is secured to the casing edge 74, for example, by welding or brazing. Fig. 16A, the dashed line indicates a welding area between the impact box 300 and the casing edge 74. For example, the impact box 300 is connected to the suction-side casing edge 74 N welded. The impact box 300 can be welded to other parts of the casing edge 74, for example to the upstream casing edge 74 L , the drain-side casing edge 74 T or the pressure-side casing edge 74 P . In addition, the impact box 300 can be welded to the blade 51.

[0058] Fig. 16B is an exemplary perspective view of a modification of the seventh embodiment. In Fig. 16B is the peripheral edge of the front wall 302 with the suction-side casing edge 74 N , the upstream shroud edge 74 L , the drain-side casing edge 74 T and the side surface of the blade 51. By welding the peripheral edge of the front wall 302 to the suction-side shroud edge 74 N , the upstream shroud edge 74 L , the drain-side casing edge 74 T and the side surface of the blade 51, a sealing structure is provided along the circumference of the front wall 302. As shown in Fig. 16B, the outlet conduit 83 may be provided to penetrate the front wall and the baffle plate (rear wall) and thus connect the inner area and the outer space.

[0059] Next, a manufacturing method of a turbine blade shroud is described. Fig. 17 is a flowchart illustrating a manufacturing process of a shroud for a turbine blade. As shown in Fig. 17, the impact box 300 is provided in a step S402. Then, in a step S404, the impact box 300 is inserted into the cavity CA of the shroud base body 72 such that the rear wall 304 faces the radially outer surface of the radially inner wall 81. Subsequently, the impact box 300 is welded to the shroud edge 74 and / or to a side surface of the airfoil 51 to provide a seal along the periphery of the front wall 302.

[0060] In these steps, the spacer 320 may provide support for the back wall 304. As in Fig. 15, the shroud base body 72 may include a spacer 320 on a surface of the radially inner wall 81. The spacer 320 provides support for the rear wall 304, thereby facilitating positioning of the impact box 300 and allowing a gap between the radially inner wall 81 of the shroud base body 72 and the rear wall 304.

[0061] According to this embodiment, by inserting and welding the impact box 300 to the outer casing 70, the inner region and the outer region of the space S of the casing main body 72 are formed. Since the seal is provided along the periphery of the front wall 302, the inner region and the outer region of the space S of the casing main body 72 can thus be formed simply by welding the impact box 300 to the suction-side casing edge 74. N , the upstream shroud edge 74 L, the drain-side casing edge 74 T and the side surface of the blade 51. In addition, the outlet line 83 can collect the cooling air and blow it out of the sealed space after impingement cooling.

[0062] The above-described embodiment is described using the outer casing 70 as an example. However, this embodiment can be similarly applied to the inner casing 60. The above-described embodiment is described using the impact box 300 installed on the suction side of the casing main body 72 as an example. It is also possible for the casing main body 72 to have another impact box 300 as a counterpart on its pressure side. The other impact box 300 has the same structure; therefore, a detailed description is omitted.

[0063] Next, the eighth embodiment of the present application will be described below. Fig. Fig. 18 is a perspective view of a guide vane according to the eighth embodiment. This embodiment will be described with exemplary use of the outer shroud 70. As shown in Fig. 18, the outer casing base body 72 has a baffle box 400. Like the baffle box 300, the baffle box 400 also has a front wall 402, a rear wall 404, and a circumferential side wall 406. The rear wall 404 has air holes 79. The baffle box 400 further has a box air inlet 408 (see Fig. 21 and Fig. 22). The front wall 402, the rear wall 404, and the circumferential side wall 406 are connected to one another, so that an airtight chamber is located within the impact box 400, which is distinct from the area of ​​the box air inlet 408 and the air holes 79.

[0064] Fig. 19 is a schematic sectional view of a guide vane according to the eighth embodiment. Fig. 20 is an enlarged partial view of Fig. 19. As in Fig. 18, the impact box 400 includes an attachment portion 410 attached to the shroud edge. The impact box 400 is connected and secured to the shroud edge 74 only in the attachment portion 410. A remaining portion of the impact box 400 is not connected to the shroud edge 74 or a sidewall of the airfoil 51, such that the remaining portion of the impact box 400 other than the attachment portion 410 is separated and spaced from the shroud edge 74 and the sidewall of the airfoil 51. For example, the circumferential sidewall 406 other than the attachment portion 410 is completely separated and spaced from the shroud edge 74, with a gap therebetween. In addition, the circumferential sidewall 406 is separated and spaced from a sidewall of the airfoil 51, with a gap therebetween.

[0065] As in Fig. 19, the outer casing 70 has a suction-side baffle box 400 N and a pressure-side impact box 400 P The suction-side impact box 400 N is equipped with the suction-side casing edge passage outlet 172 N The pressure-side impact box 400 P is connected to the pressure-side casing edge passage outlet 172 P The description is based on the suction-side impact box 400 as an example. N The pressure-side impact box 400 P has the same structure; a detailed description is omitted. Fig. 20 shows the gap GA between the suction-side baffle box 400 N and (i) the suction-side casing edge 74 N , (ii) the upstream shroud edge 74 L and (iii) the side wall of the blade 51. The gap GA between the suction-side baffle box 400 Nand the suction-side casing edge 74 N is arranged on both sides of the fastening area 410. The gap GA is arranged so that it surrounds the suction-side impact box 400 N surrounds. As in Fig. 19, the gap GA is also between the suction-side impact box 400 N and the drain-side casing edge 74 T The gap GA is also arranged between the suction-side impact box 400 N and the casing edge passage inlet 171 T A cover plate 430 is arranged to cover the mounting area 410.

[0066] The structure and location of the gap GA is not limited to this embodiment. The fastening region 410 can also be arranged in another region of the impact box 400, for example, in a region corresponding to another shroud edge, for example, the upstream shroud edge 74. L, corresponds. In such a modification, the gap GA is arranged to surround the impact box 400 except for the modified attachment portion 410. Also, a plurality of attachment portions may be arranged on the impact box 400 so that they are attached to the shroud edge 74 or the airfoil 51. In such a structure, a plurality of gaps are arranged between adjacent attachment portions.

[0067] Fig. 21 is an enlarged partial view of the impact box. Fig. 21 illustrates a portion of the impact box 400 arranged around the mounting portion 410. The impact box 400 includes a box air inlet 408. The impact box 400 further includes an additional part 412 having a U-shape surrounding the box air inlet 408. The additional part 412 protrudes beyond the circumferential side wall 406.

[0068] Fig. 22 is a sectional view along the line XXII-XXII of Fig. 20. As in Fig. 22, the end face of the additional part 412 lies on an inner side surface of the suction-side casing edge 74 N The additional part 412 is attached to the inner side surface of the suction-side casing edge 74 N and secured thereto, for example by welding. The connection of the impact box 400 to the casing edge 74 is limited to the connection between the additional part 412 and the suction-side casing edge 74 Nlimited. Due to this structure, the impact box 400 is cantilevered by means of this connection. A spacer 420 is arranged on an outer surface of the radially inner wall 81 to provide support for the rear wall 404 of the impact box 400, thereby facilitating positioning of the impact box 400 and allowing space between the radially inner wall 81 of the shroud base 72 and the rear wall 404. A plurality of spacers 420 can be arranged on the radially inner wall 81.

[0069] As in Fig. 22, the box air inlet 408 is connected to the suction side casing edge passage outlet 172 N in connection, so that the inside of the suction-side casing edge passage 75 N flowing cooling air from the suction-side casing edge passage outlet 172 N flows out to the box air inlet 408.

[0070] The Fig. 23A and Fig. 23B are schematic sectional views of a guide vane according to the eighth embodiment. As in Fig. 23A, the suction-side shroud edge passage outlet 172N is open after the end face of the additional part 412 is pressed against the inner side surface of the suction-side shroud edge 74 N and secured, for example, by welding. Thus, as in Fig. 23B, the cover plate 430 is applied to the connecting area between the suction-side shroud edge passage outlet 172 N and the box air inlet 408 to provide an airtight structure or chamber or passage extending between the suction side shroud edge passage outlet 172 N and the box air inlet 408. The cover plate 430 is attached to the casing edge 74 N, attached to a surface of the additional part 412 (top surface and inclined surface) and to a surface of the front wall 402, for example by welding.

[0071] Next, a manufacturing method of a turbine blade shroud is described. Fig. 24 is a flowchart illustrating a manufacturing process of a shroud for a turbine blade. As shown in Fig. 24, the impact box 400 is prepared in a step S502. Then, in a step S504, the impact box 400 is inserted into the cavity CA of the shroud base body 72 such that the rear wall 404 faces the radially outer surface of the radially inner wall 81. Subsequently, in a step S506, the impact box 400 is welded to the shroud edge 74 in the attachment region 410, while other regions of the impact box 400 are spaced from the shroud edge 74 and the side wall of the blade 51, thereby providing a cantilevered structure such that the gap GA is arranged to surround the impact box 400 except for the attachment region 410. More specifically, the additional part 412 is welded to the suction-side shroud edge 74 Nwelded. In these steps, the spacer 420 can provide support for the rear wall 404. Thereafter, in a step S508, the cover plate 430 is applied so that it covers the passage from the suction-side shroud edge passage outlet 172 N to the box air inlet 408.

[0072] Fig. 25 is a schematic sectional view of a guide vane according to the eighth embodiment. Fig. 25 represents the air flow of cooling air from the suction side shroud edge passage outlet 172 N into the impact box 400 and outside the impact box 400. As in Fig. 25, the air flows within the suction-side casing edge passage 75 N flowing cooling air from the suction-side casing edge passage outlet 172 Nout through the box air inlet 408 into the impingement box 400. Then, for impingement cooling of a radially outer surface of the radially inner wall 81, the cooling air is expelled from the air holes 79 toward the radially outer surface of the radially inner wall 81, subsequently blown outward through the gap GA, and then returned to the interior of the combustion chamber housing. The gap GA connects the inner region (cavity) of the cavity (S) and an outer space located on the side of the front wall 402 opposite the cavity (S). Fig. 25, the gap GA is shown, for example, at a location between the circumferential sidewall 406 and the sidewall of the blade 51.

[0073] According to this embodiment, the inner and outer regions of the space S of the shroud base body 72 are formed by inserting the baffle box 400 into the cavity of the shroud base body 72 and welding the baffle box 400 to the attachment portion. This makes it easy to provide a shroud with a cooling structure having an effectively sealed chamber by supporting the baffle box through the shroud edge. Furthermore, after the radially inner wall 81 is impinged, the cooling air is blown out and collected through the gap GA. This eliminates the need to provide a separate structure (path) for blowing out and collecting the cooling air after the impingement cooling.

[0074] The inventors' investigations have shown that during turbine operation, a temperature difference may occur between the shroud edge 74 and the impact box 400, which may generate thermal stress at the joint area between the shroud edge 74 and the impact box 400. According to this embodiment, the impact box 400 is supported by the cantilever structure, and the gap GA surrounds the impact box 400 so that the gap GA can absorb the effects of thermal expansion to reduce the thermal stress.

[0075] Fig. Figure 26 is a schematic cross-sectional view of a guide vane showing the principle of the eighth embodiment. As shown in Fig. 26, the casing edge passage 75 N with the interior of the impact box 400. If the outlet of the casing edge passage is in the area of ​​the casing edge passage 75 Nwhich faces the impact box 400, a low flow velocity area LFVA (Low Flow Velocity Area) is created due to the flow of the cooling air in the direction of the impact box 400, in which a flow velocity of the cooling air within the casing edge passage 75 N As in Fig. 22, in this embodiment the suction-side casing edge 74 N a diagonally running casing edge outlet passage 75 OP which the suction-side casing edge passage 75 N with the suction-side passage outlet 172 N More precisely, the suction-side casing edge has 74 N one on one side of the casing edge 74 N arranged opposite side wall 74 OSW , which is one side of the casing edge 74 N and faces the hot gas passage of the turbine (this side is in Fig. 22 with the reference numeral 81), and an inner side wall 74 facing the impact box 400 ISW The opposite side wall 74 OSW and the inner side wall 74 ISW delimit an interior space of the casing edge passage 75 N .

[0076] The casing edge outlet passage 75 OP has a suction-side casing edge passage 75 N connected inlet end and one with the suction side passage outlet 172 N connected outlet end. The casing edge outlet passage 75 OP is in the opposite side wall 74 OSW More specifically, the inlet end of the shroud edge outlet passage 75 OP in the radially opposite side wall 74 OSW The inlet end of the casing edge outlet passage 75 OPlocated near the potential low flow velocity region LFVA, so that the shroud edge outlet passage 75 OP connected to the potential low flow velocity region LFVA. This structure, in which the inlet end of the shroud edge outlet passage 75 OP is arranged near the potential low flow velocity region LFVA, formation of the potential low flow velocity region LFVA in the shroud edge passage can be reduced.

[0077] The structure of the guide vane is not limited to this embodiment. For example, the outlet end of the shroud edge outlet passage 75 OP in the inner side wall 74 ISW be arranged.

[0078] Next, a ninth embodiment will be described. Fig. 27 is a schematic sectional view according to the ninth embodiment. Fig. 27 represents an area of ​​the sheath corresponding Fig. 22. Fig. 28 is a schematic bottom view according to the ninth embodiment. Fig. 28 schematically shows a bottom view of the rear wall 404 of the impact box 400. As in Fig. 27, the impact box 400 has a rear wall 404 facing the cooling surface of the radially inner wall 81. As shown in Fig. 27 and Fig. As shown in Figure 28, the backplane 404 has a thicker region 440 near the attachment region 410. The thicker region 440 has a thickness T1 that is greater than the thickness T2 of the remaining region of the backplane 404. With this structure with the thicker region 440, thermal deformation and thermal stress at the attachment region 410 and thereby low-cycle fatigue can be prevented.

[0079] The thicker region 440 of the rear wall 404 has air holes 79. The air holes 79 arranged in the thicker region 440 can have a diameter that is larger than the diameter of the air holes 79 arranged in the remaining region of the rear wall 404. For example, the diameter of the air holes 79 can be predetermined such that the ratio R between the thickness T and the diameter D (T:D) is constant.

[0080] As in Fig. As shown in Figure 27, the impact box 400 includes a support structure 450, such as a support pin, within its interior. The impact box 400 includes a hollow chamber between the front wall 402 and the rear wall 404. The support pin 450 is a columnar structure attached at one end to the front wall 402 and at an opposite end to the rear wall 404. A plurality of support pins 450 may be disposed within the impact box 400, and the plurality of support pins 450 may be arranged at regular intervals.

[0081] The inventors' investigations have shown that during turbine operation, a pressure difference may occur between the interior and exterior of the impact box 400, which may cause the impact box 400 to bulge. By providing the support pin 45, which connects and holds the front wall 402 and the rear wall 404 together, bulging of the impact box 400, which would separate the front wall 402 from the rear wall 404, can be prevented.

[0082] The structure of the guide vane is not limited to this embodiment. Fig.29 is an exemplary schematic sectional view of a modification of the ninth embodiment. In this embodiment, the baffle box 400 includes a support structure 460, which also functions similarly to the exhaust duct 83. The support pin 460 is a columnar structure fixed at one end to the front wall 402 and at an opposite end to the rear wall 404. The support pin 460 further has a hollow passage inside it and extends through the front wall 402 and the baffle plate (rear wall 404) to connect the interior and exterior spaces, thus collecting and discharging the cooling air after impingement cooling.

[0083] The foregoing embodiments are described using the outer casing 70 as an example. However, the embodiments can be similarly applied to the inner casing 60. The present disclosure is not limited to the above-described embodiment and can be embodied in various embodiments. While a specific form of embodiment has been described above and illustrated in the accompanying drawings for the purpose of clarity of understanding, the above description has been made by way of example and not as a limitation on the scope of the invention defined by the appended claims. The scope of the invention is intended to be determined by the appended claims. Various modifications obvious to one of ordinary skill in the art may be made without departing from the scope of the invention. The appended claims cover such modifications. LIST OF REFERENCE SYMBOLS 10 gas turbines 20 turbines 22 Turbine housing 24 Rotor shaft 26 Turbine rotor Ar axis 30 combustion chamber 50 guide vanes 51 Blade body (blade) 51 P Partition walls 52 leading edge 53 Drainage edge 54 suction-side surface 55 print-side area 56 intake manifold 57 outer air duct 58 Air intake 59 openings 141, 142, 143 Air duct 151, 152, 153 Use 161, 162, 163 inner air duct 191, 192, 193, 194, 195 air duct 154 Blade cooling structure 164 pin ribs 60 inner sheath 70 outer sheath 62, 72 Sheathing base body 63, 73 impact plate 64, 74 sheathing edge 65, 75 Sheathing edge passage S cavity 171 Sheath edge passage inlet 172 Casing edge passage outlet 175 Turbulator 76 peripheral wall 78 Gas path area 79 air holes 81 radial inner wall 82 radial outer wall 83 Outlet line 181 Sheath edge passage inlet 182 Casing edge passage outlet 300,400 impact box 302,402 front wall 304, 404 rear wall 306, 406 surrounding side wall 308,408 box air intake 320, 420 spacers 410 mounting area 412 Additional part 430 cover plate 440 thicker area 450, 460 support pin QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 9,638,047 [0002, 0003]

Claims

[1] Turbine blade shroud, comprising: a casing base body having a first wall with a gas path surface facing a hot gas passage of the turbine and a cooling surface facing away from the hot gas passage; a sheathing edge arranged on a periphery of the sheathing base body and thus surrounding the sheathing base body, the sheathing edge having a sheathing edge passage arranged therein; and a baffle box arranged to face the cooling surface of the first wall and to be spaced apart from the cooling surface of the first wall, wherein the baffle box has a cooling air inlet for introducing cooling air from the shroud edge passage into an interior of the baffle box and an impact air hole which is provided for ejecting the introduced cooling air onto the cooling surface of the first wall in order to cool the cooling surface of the first wall. [2] A turbine blade shroud according to claim 1, wherein a periphery of the impact box has a fastening portion secured to the shroud edge. [3] A turbine blade shroud according to claim 1, wherein the shroud has a cooling air collecting passage arranged to collect the cooling air discharged to cool the cooling surface of the first wall. [4] A turbine blade shroud according to claim 2, wherein the periphery of the impact box includes a non-attachment region having a gap between the shroud edge and the periphery of the impact box. [5] A turbine blade shroud according to claim 4, wherein the shroud has a cooling air collecting passage arranged to collect the cooling air discharged to cool the cooling surface of the first wall, and wherein the gap forms the cooling air collecting passage. [6] A turbine blade shroud according to claim 5, wherein the gap communicates with a space between the impact box and the cooling surface of the first wall. [7] A turbine blade shroud according to claim 2, wherein the impact box is cantilevered due to the attachment portion attached to the shroud edge. [8] A turbine blade shroud according to claim 2, wherein the baffle box has a back wall facing the cooling surface of the first wall, and the back wall has a thicker region near the attachment region, the thicker region having a thickness greater than that of the remaining region of the back wall. [9] A turbine blade shroud according to claim 2, wherein the baffle box has a rear wall facing the cooling surface of the first wall and a front wall opposite the rear wall with a hollow chamber therebetween, and wherein the baffle box further comprises a support structure attached to the front wall at one end and attached to the rear wall at an opposite end. [10] A turbine blade shroud according to claim 9, wherein the support structure has a passage arranged to collect and discharge the cooling air expelled to cool the cooling surface of the first wall. [11] A turbine blade shroud according to claim 10, wherein a periphery of the leading wall is welded to the shroud edge to provide a seal along the weld. [12] A turbine blade shroud according to claim 1, wherein the shroud body has a cavity defined by the first wall and the shroud edge, and wherein the impact box is inserted into the cavity and partially attached to the shroud edge. [13] A turbine blade shroud according to claim 1, wherein the shroud base body has a cavity defined by the first wall and the shroud edge, and wherein the impact box is inserted into the cavity, the shroud edge comprising: an opposite side wall arranged on a side of the shroud edge opposite a side of the shroud edge facing the hot gas passage of the turbine, an inner side wall facing the impact box, the opposite side wall and the inner side wall defining the shroud edge passage, and a shroud edge outlet passage provided to connect the shroud edge passage to the cooling air inlet of the impact box in order to introduce the cooling air flowing inside the shroud edge passage into the cooling air inlet of the impact box, and wherein the shroud edge outlet passage is arranged in the opposite side wall of the shroud edge. [14] A turbine blade shroud according to claim 13, wherein the shroud edge outlet passage has an inlet end connected to the shroud edge passage, and the inlet end of the shroud edge outlet passage is disposed in the opposite sidewall of the shroud edge. [15] A turbine blade shroud according to claim 2, wherein the attachment portion comprises an attachment adapted to project beyond a side surface of the impact box, the attachment being securely attached to the shroud edge. [16] A turbine blade shroud according to claim 15, wherein the additional part is intended to surround the cooling air inlet. [17] A turbine blade shroud according to claim 16, wherein the baffle box comprises a cover disposed over an opening of the cooling air inlet. [18] A method for producing a shroud of a turbine blade, the shroud comprising: a casing base body having a first wall with a gas path surface facing a hot gas passage of the turbine and a cooling surface facing away from the hot gas passage, and a casing edge arranged on a circumference of the casing base body and thus surrounding the casing base body, wherein the casing edge has a casing edge passage arranged therein, the method comprising: Arranging a baffle box such that it faces the cooling surface of the first wall and is spaced from the cooling surface of the first wall; wherein the baffle box has a cooling air inlet for introducing cooling air from the shroud edge passage into an interior of the baffle box and an impact air hole which is provided for ejecting the introduced cooling air onto the cooling surface of the first wall in order to cool the cooling surface of the first wall. [19] A method of manufacturing a shroud of a turbine blade according to claim 18, further comprising: attaching a portion of a periphery of the impact box to the shroud edge. [20] A method of manufacturing a shroud of a turbine blade according to claim 18, further comprising: providing a cooling air collecting passage arranged to collect the cooling air discharged to cool the cooling surface of the first wall.

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