Assembly method for gas turbine and radial turbine nozzles

Abstract

To provide a radial turbine nozzle which can be favorably assembled to a gas turbine.SOLUTION: In a method of assembling a radial turbine nozzle 10 to a gas turbine, the radial turbine nozzle 10 is assembled in a state where a first ring 62 and a second ring 64 are assembled to an outer peripheral portion of a nozzle body 60. The radial turbine nozzle 10 is disposed at the radial outer side of the first holder 34 so that an inner peripheral part of the nozzle body 60 can be seated on the first holder 34 and multiple segments 80 may move in a radial direction of a radial turbine.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a method for assembling a gas turbine and a radial turbine nozzle.

Background Art

[0002] Patent Document 1 discloses a gas turbine including a radial turbine and a radial turbine nozzle (inlet nozzle) surrounding the radial turbine. The radial turbine nozzle includes an annular nozzle body. The nozzle body includes a plurality of blades, a first end wall (ring plate), and a second end wall (ring plate). The plurality of blades are arranged at a predetermined interval in the circumferential direction of the radial turbine. The first end wall is connected to one end portion of the plurality of blades in the axial direction of the radial turbine. The second end wall is connected to the other end portion of the plurality of blades in the axial direction.

[0003] The nozzle body has a plurality of segments (split pieces). The plurality of segments are connected in the circumferential direction. Each of the plurality of segments has a first split annular portion and a second split annular portion. The first split annular portion is formed by dividing the first end wall with a plurality of first split surfaces inclined with respect to the radial direction of the radial turbine. The second split annular portion is formed by dividing the second end wall with a plurality of second split surfaces inclined with respect to the radial direction.

[0004] A back plate having a stepped portion is provided in a turbine housing that houses the radial turbine. The first end wall is arranged on the back plate. The second end wall is arranged in an annular groove formed in the turbine housing. The first end wall abuts against the stepped portion of the back plate by being pressed radially outward by a ring spring. Thereby, the radial turbine nozzle is positioned and fixed in the radial direction.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Application Publication No. 4-112902 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] In Patent Document 1, the radial turbine nozzle is positioned and fixed by the pressing force from the ring spring to the first end wall, making it difficult to properly assemble the radial turbine nozzle to the gas turbine. Furthermore, when the gas turbine is in use, the combustion gas passing through the radial turbine nozzle causes the casing, consisting of the back plate and turbine housing, to become hot. As a result, the dimensions of the back plate and turbine housing change due to thermal expansion, and the clearance between multiple segments increases. Consequently, the performance of the gas turbine may deteriorate.

[0007] The present invention aims to solve the problems described above. [Means for solving the problem]

[0008] A first aspect of the present invention is a gas turbine comprising a radial turbine, a radial turbine nozzle surrounding the radial turbine, and a holding portion for holding the radial turbine nozzle, wherein the radial turbine nozzle comprises a plurality of blades arranged at predetermined intervals in the circumferential direction of the radial turbine, an annular nozzle body having a first end wall connected to one end of the plurality of blades in the axial direction of the radial turbine, and a second end wall connected to the other end of the plurality of blades in the axial direction, a first ring surrounding the first end wall, and a second ring surrounding the second end wall, wherein the nozzle body has a plurality of segments connected along the circumferential direction, and the first ring is recessed radially outward of the radial turbine and extends in the circumferential direction The nozzle has a side groove, the second ring has a second outer groove that is recessed radially outward and extends circumferentially, each of the plurality of segments has a first divided annular portion formed by dividing the first end wall with a plurality of first dividing surfaces inclined radially, and a second divided annular portion formed by dividing the second end wall with a plurality of second dividing surfaces inclined radially, the outer circumferential portion of the first divided annular portion has a first flange portion that protrudes radially outward, the first flange portion is inserted into the first outer groove, the outer circumferential portion of the second divided annular portion has a second flange portion that protrudes radially outward, the second flange portion is inserted into the second outer groove, the inner circumferential portion of the nozzle body is seatable on the holding portion, and the plurality of segments are movable radially.

[0009] A second aspect of the present invention is a method for assembling a radial turbine nozzle, the radial turbine nozzle comprising: a plurality of blades arranged at predetermined intervals in the circumferential direction of a radial turbine; an annular nozzle body having a plurality of blades arranged at predetermined intervals in the circumferential direction of the radial turbine; a first end wall connected to one end of the plurality of blades in the axial direction of the radial turbine; a second end wall connected to the other end of the plurality of blades in the axial direction; a first ring surrounding the first end wall; and a second ring surrounding the second end wall, wherein the nozzle body has a plurality of segments connected along the circumferential direction; the first ring has a first outer groove recessed outward in the radial direction of the radial turbine and extending in the circumferential direction; the second ring has a second outer groove recessed outward in the radial direction and extending in the circumferential direction; and each of the plurality of segments has a plurality of first divisions inclined with respect to the radial direction of the first end wall The nozzle comprises a first divided annular portion formed by dividing it with a surface, and a second divided annular portion formed by dividing the second end wall with a plurality of second dividing surfaces inclined with respect to the radial direction, wherein the outer circumferential portion of the first divided annular portion has a first flange portion projecting outward in the radial direction, and the first flange portion is inserted into the first outer groove, and the outer circumferential portion of the second divided annular portion has a second flange portion projecting outward in the radial direction, and the second flange portion is inserted into the second outer groove, and the assembly method comprises a nozzle assembly step of assembling the radial turbine nozzle with the first ring and the second ring assembled to the outer circumferential portion of the nozzle body, and a nozzle arrangement step of positioning the radial turbine nozzle on the radial side of the holding portion such that the inner circumferential portion of the nozzle body can be seated against the holding portion of the gas turbine and the plurality of segments can move in the radial direction. [Effects of the Invention]

[0010] According to the present invention, during gas turbine operation, the inner circumference of the nozzle body is seated on the holding part by the pressure of the combustion gas passing through the radial turbine nozzle. During gas turbine operation, the holding part is at a lower temperature than the radial turbine nozzle. Therefore, the holding part experiences less dimensional change due to thermal expansion. This allows the radial turbine nozzle assembled to the gas turbine to be precisely positioned and fixed. Furthermore, the first and second dividing surfaces are inclined with respect to the radial direction of the radial turbine. This makes it possible to easily move multiple segments in the radial direction of the radial turbine when the combustion gas passes through the radial turbine nozzle. In addition, the clearance between the holding part and the radial turbine nozzle allows the radial turbine nozzle to be easily assembled to the gas turbine. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a cross-sectional view of a gas turbine. [Figure 2] Figure 2 is a perspective view of a radial turbine nozzle. [Figure 3] Figure 3 is a partial perspective view showing a fractured radial turbine nozzle. [Figure 4] Figure 4 is a partial perspective view showing a fractured radial turbine nozzle. [Figure 5] Figure 5 is a cross-sectional view of a radial turbine nozzle. [Figure 6] Figure 6 is a cross-sectional view of a radial turbine nozzle. [Figure 7] Figure 7 is a cross-sectional view of a radial turbine nozzle. [Figure 8] Figure 8 is a partial side view of a radial turbine nozzle. [Figure 9] Figure 9 is a flowchart showing the assembly method of the radial turbine nozzle and the method of installing the radial turbine nozzle onto the gas turbine. [Figure 10] Figure 10 is a cross-sectional view illustrating the assembly method of a radial turbine nozzle. [Figure 11] Figures 11A and 11B are partial perspective views illustrating the connection of a plurality of segments.

BEST MODE FOR CARRYING OUT THE INVENTION

[0012] FIG. 1 is a cross-sectional view of a gas turbine 12 including a radial turbine nozzle 10.

[0013] The gas turbine 12 includes a housing 14, a shaft 16, a radial turbine 18, a radial turbine nozzle 10, a shroud case 20, a compressor wheel 22, a diffuser 24, a combustor 26, and a gas discharge portion 28. Each of the above components of the gas turbine 12 is made of a heat-resistant metal material.

[0014] The housing 14 has an annular first housing 30 and an annular second housing 32. The first housing 30 and the second housing 32 are connected along the axial direction (the left-right direction in FIG. 1) of the gas turbine 12. The axial direction of the gas turbine 12 is the axial direction of the radial turbine 18. Hereinafter, the axial direction of the radial turbine nozzle 10 is also simply referred to as the "axial direction". One end portion of the first housing 30 along the axial direction is connected to the housing (not shown) of a rotating electric machine. The other end portion of the first housing 30 along the axial direction is connected to the second housing 32.

[0015] The shroud case 20 is a hollow body disposed inside the housing 14. The shroud case 20 is fixed to the inner peripheral surface of the first housing 30.

[0016] The shaft 16 is disposed coaxially with the radial turbine 18 inside the housing 14. The shaft 16 is disposed inside the housing 14 so as to penetrate through the shroud case 20. One end portion of the shaft 16 along the axial direction is connected to the rotating shaft (not shown) of a rotating electric machine. The other end portion of the shaft 16 along the axial direction is connected to the radial turbine 18.

[0017] The compressor wheel 22 is attached to the shaft 16 inside the shroud case 20. In FIG. 1, the connection portion between the compressor wheel 22 and the shaft 16 is not shown. When the rotating shaft of the rotating electric machine rotates, the shaft 16, the compressor wheel 22, and the radial turbine 18 can rotate integrally. In the space formed between the compressor wheel 22 and the shroud case 20, air taken in from the outside flows as indicated by the dashed arrow. As the compressor wheel 22 rotates, the air taken in from the outside is compressed and becomes compressed air.

[0018] Inside the second housing 32, the other end of the shaft 16, the radial turbine 18, the radial turbine nozzle 10, a part of the shroud case 20, a part of the compressor wheel 22, the diffuser 24, the combustor 26, and the gas discharge portion 28 are arranged. Inside the second housing 32, a first holder 34 (holding portion) and a second holder 36 are arranged.

[0019] The diffuser 24 is a hollow body. The diffuser 24 is fixed to the inner peripheral surface of the first housing 30 together with the shroud case 20. The diffuser 24 is arranged inside the second housing 32 so as to surround a part of the shroud case 20, a part of the compressor wheel 22, the first holder 34, and the radial turbine 18. The diffuser 24 allows the compressed air generated by the compressor wheel 22 to flow through.

[0020] The first holder 34 is an annular hollow body. The outer peripheral portion of the first holder 34 is fixed to the diffuser 24. The first holder 34 surrounds the back side of the radial turbine 18 connected to the shaft 16. An annular seal ring 38 is inserted between the inner peripheral portion of the first holder 34 and the compressor wheel 22.

[0021] <{ The combustor 26 is an annular component. The combustor 26 is fixed to the diffuser 24 together with the first holder 34. The combustor 26 surrounds the radial turbine nozzle 10, the radial turbine 18, and the gas exhaust section 28.

[0022] An annular gas flow passage 40 is formed between the inner surface of the second housing 32 and the combustor 26. The gas flow passage 40 supplies compressed air introduced from the diffuser 24 to the combustor 26, as indicated by the dashed arrow. The combustor 26 has an inlet 42 for introducing compressed air. A fuel supply nozzle 44 is fixed to the second housing 32. The fuel supply nozzle 44 is positioned to enter the inlet 42 of the combustor 26. The fuel supply nozzle 44 supplies fuel to the combustor 26.

[0023] The combustor 26 has a plurality of relay holes 46. The plurality of relay holes 46 connect the gas flow passage 40 to the inside of the combustor 26.

[0024] The combustor 26 generates high-temperature combustion gas by mixing fuel supplied from the fuel supply nozzle 44 with compressed air and burning it. The combustion gas is discharged to the radial turbine nozzle 10 through an outlet 48 formed in the combustor 26, as indicated by the dashed arrow.

[0025] The radial turbine nozzle 10 is positioned inside the second housing 32 so as to face the exhaust port 48 of the combustor 26. The radial turbine nozzle 10 is an annular component that surrounds the radial turbine 18. Annular seal rings 50 and 52 are interposed between the radial turbine nozzle 10 and the combustor 26.

[0026] The gas discharge section 28 is an annular member. One end of the gas discharge section 28 along the axial direction is curved outward in the radial direction (up and down direction in Figure 1) of the radial turbine 18. Hereafter, the radial direction of the radial turbine 18 will also be simply referred to as the "radial direction". One end of the gas discharge section 28 faces the first holder 34 along the axial direction. A part of the gas discharge section 28, including one end, surrounds a part of the radial turbine 18. The part of the gas discharge section 28 that surrounds a part of the radial turbine 18 is configured as the second holder 36. The other end of the gas discharge section 28 along the axial direction is fixed to the second housing 32. An outlet 54 is formed at the other end of the gas discharge section 28.

[0027] The combustion gas introduced into the radial turbine 18 via the radial turbine nozzle 10 rotates the radial turbine 18. The combustion gas is then released as exhaust gas. Gas discharge section 28 It is discharged to the outside from the discharge port 54.

[0028] The first holder 34 and the second holder 36 hold the radial turbine nozzle 10 radially inward.

[0029] Next, the configuration of the radial turbine nozzle 10 will be explained with reference to Figures 2 to 8.

[0030] As shown in Figures 2 to 4, the radial turbine nozzle 10 comprises a nozzle body 60, a first ring 62, a second ring 64, a first pressing member 66, and a second pressing member 68.

[0031] The nozzle body 60 has a plurality of blades 70, an annular first end wall 72, and an annular second end wall 74.

[0032] Multiple blades 70 are arranged at predetermined intervals in the circumferential direction of the radial turbine 18 (the direction around the axis of the radial turbine 18). Hereinafter, the circumferential direction of the radial turbine 18 will also be simply referred to as the "circumferential direction". As shown in Figures 3 and 8, each of the multiple blades 70 is formed in an airfoil shape. Each of the multiple blades 70 is inclined with respect to the radial and circumferential directions. The thickness of each of the multiple blades 70 decreases towards the inside in the radial direction.

[0033] As shown in Figures 3 to 7, the first end wall 72 is connected to one end of the multiple blades 70 in the axial direction. The second end wall 74 is connected to the other end of the multiple blades 70 in the axial direction. Each of the first end wall 72 and the second end wall 74 protrudes radially beyond the multiple blades 70.

[0034] As shown in Figures 2 and 3, the first ring 62 is an annular member surrounding the first end wall 72. The second ring 64 is an annular member surrounding the second end wall 74.

[0035] As shown in Figures 3 to 7, the first ring 62 has a first outer groove 76. The first outer groove 76 is formed on the inner circumference of the first ring 62. The first outer groove 76 is recessed radially outward on the inner circumference of the first ring 62. The first outer groove 76 extends in an annular shape circumferentially on the inner circumference of the first ring 62.

[0036] The second ring 64 has a second outer groove 78. The second outer groove 78 is formed on the inner circumference of the second ring 64. The second outer groove 78 is recessed radially outward on the inner circumference of the second ring 64. The second outer groove 78 extends in an annular shape circumferentially on the inner circumference of the second ring 64.

[0037] The nozzle body 60 has multiple segments 80. The nozzle body 60 is formed by connecting the multiple segments 80 along the circumferential direction.

[0038] Each of the multiple segments 80 has a blade 70, a first divided annular portion 82, and a second divided annular portion 84.

[0039] As shown in Figures 3 and 4, the first end wall 72 is divided by a plurality of first dividing surfaces 86. Each of the plurality of first dividing surfaces 86 is inclined with respect to the radial and circumferential directions. The first divided annular portion 82 is formed by dividing the first end wall 72 by a plurality of first dividing surfaces 86.

[0040] The second end wall 74 is divided by a plurality of second dividing surfaces 88. Each of the plurality of second dividing surfaces 88 is inclined with respect to the radial and circumferential directions. The second divided annular portion 84 is formed by dividing the second end wall 74 by a plurality of second dividing surfaces 88.

[0041] In each segment 80, the first dividing surface 86 and the second dividing surface 88 on one end along the circumferential direction are parallel to each other. In each segment 80, the first dividing surface 86 and the second dividing surface 88 on the other end along the circumferential direction are parallel to each other.

[0042] As shown in Figures 5 to 7, the outer circumference of the first divided annular portion 82 protrudes outward in the axial direction. A first flange portion 90 is formed on the axially outer portion of the outer circumference of the first divided annular portion 82. The first flange portion 90 protrudes outward in the radial direction and extends in the circumferential direction. The first flange portion 90 is inserted into the first outer groove 76 of the first ring 62. As shown in Figures 5 and 6, immediately after the radial turbine nozzle 10 is assembled to the gas turbine 12, the stepped portion 91 adjacent to the first flange portion 90 on the outer circumference of the first divided annular portion 82 is in contact with the inner circumference of the first ring 62.

[0043] As shown in Figures 5 to 7, a first projection 92 is provided on the inner circumference of the first divided annular portion 82. The first projection 92 protrudes axially outward from the inner circumference of the first divided annular portion 82 and extends in the circumferential direction. A first inner groove 94 is formed in the first projection 92. The first inner groove 94 is formed on the radially outer portion of the first projection 92. The first inner groove 94 is recessed radially inward. The first inner groove 94 extends in the circumferential direction (see Figures 3 and 4).

[0044] A first inner circumferential projection 96 is formed on the inner circumferential portion of the first ring 62. The first inner circumferential projection 96 is formed on the inner circumferential portion of the first ring 62, axially outward from the first outer groove 76. The first inner circumferential projection 96 protrudes radially inward from the inner circumferential portion of the first ring 62. The first inner circumferential projection 96 is spaced axially outward from the first flange portion 90 of each of the multiple segments 80. The first inner circumferential projection 96 extends in an annular shape along the circumferential direction (see Figures 3 and 4).

[0045] The outer circumferential portion of the second divided annular portion 84 protrudes outward in the axial direction. A second flange portion 98 is formed on the axially outer portion of the outer circumferential portion of the second divided annular portion 84. The second flange portion 98 protrudes outward in the radial direction and extends in the circumferential direction. The second flange portion 98 is inserted into the second outer groove 78. As shown in Figures 5 and 6, immediately after the radial turbine nozzle 10 is assembled to the gas turbine 12, the stepped portion 99 adjacent to the second flange portion 98 on the outer circumferential portion of the second divided annular portion 84 is in contact with the inner circumferential portion of the second ring 64.

[0046] As shown in Figures 5 to 7, a second projection 100 is provided on the inner circumference of the second divided annular portion 84. The second projection 100 protrudes axially outward from the inner circumference of the second divided annular portion 84 and extends in the circumferential direction. A second inner groove 102 is formed in the second projection 100. The second inner groove 102 is formed on the radially outer portion of the second projection 100. The second inner groove 102 is recessed radially inward. The second inner groove 102 extends in the circumferential direction.

[0047] A second inner circumferential projection 104 is formed on the inner circumferential portion of the second ring 64. The second inner circumferential projection 104 is formed on the inner circumferential portion of the second ring 64, axially outward from the second outer groove 78. The second inner circumferential projection 104 protrudes radially inward from the inner circumferential portion of the second ring 64. The second inner circumferential projection 104 is spaced axially outward from the second flange portion 98 of each of the multiple segments 80. The second inner circumferential projection 104 extends along the circumferential direction.

[0048] As shown in Figures 2 to 4, the first pressing member 66 is an annular leaf spring. As shown in Figures 3 to 7, the first pressing member 66 is positioned between the first end wall 72 and the first ring 62. Specifically, the outer circumference 106 of the first pressing member 66 is positioned between the first inner circumferential projection 96 and the outer circumference portion of the first segmented annular portion 82 in each of the multiple segments 80. The inner circumference 108 of the first pressing member 66 is positioned in the first inner groove 94.

[0049] The first inner circumferential projection 96 presses the outer circumferential portion 106 of the first pressing member 66 inward in the axial direction. That is, the first inner circumferential projection 96 presses the outer circumferential portion 106 of the first pressing member 66 toward the nozzle body 60. The inner circumferential portion 108 of the first pressing member 66 presses each of the first segmented annular portions 82 of the plurality of segments 80 inward in the axial direction.

[0050] The second pressing member 68 is an annular leaf spring similar to the first pressing member 66. The second pressing member 68 is positioned between the second end wall 74 and the second ring 64. Specifically, the outer circumference 110 of the second pressing member 68 is positioned between the second inner circumferential projection 104 and the outer circumference portion of the second divided annular portion 84 in each of the multiple segments 80. The inner circumference 112 of the second pressing member 68 is positioned in the second inner groove 102.

[0051] The second inner circumferential projection 104 presses the outer circumferential portion 110 of the second pressing member 68 inward in the axial direction. That is, the second inner circumferential projection 104 presses the outer circumferential portion 110 of the second pressing member 68 toward the nozzle body 60. The inner circumferential portion 112 of the second pressing member 68 presses each of the second segmented annular portions 84 of the plurality of segments 80 inward in the axial direction.

[0052] As shown in Figures 3 and 4, a first notch 114 is formed in the first projection 92 of at least one of the multiple segments 80. The first notch 114 penetrates the first projection 92 in the axial direction. The first notch 114 communicates with the first inner groove 94. Figures 3 and 4 illustrate the case in which the first notch 114 is formed in each of the multiple segments 80.

[0053] As shown in Figures 3, 4, 6, and 7, a first projection 116 is provided on the inner circumference 108 of the first pressing member 66. The first projection 116 protrudes outward in the axial direction from the inner circumference 108 of the first pressing member 66. The first projection 116 is inserted into the first notch 114.

[0054] As shown in Figure 8, a second notch 118 is formed in the second projection 100 of at least one of the multiple segments 80 (see Figures 3 to 7). The second notch 118 penetrates the second projection 100 in the axial direction. The second notch 118 communicates with the second inner groove 102 (see Figure 5). Note that Figure 8 illustrates the case in which the second notch 118 is formed in each of the multiple segments 80.

[0055] As shown in Figures 4, 6, 7, and 8, a second projection 120 is provided on the inner circumference 112 of the second pressing member 68. The second projection 120 protrudes outward in the axial direction from the inner circumference 112 of the second pressing member 68. The second projection 120 is inserted into the second notch 118.

[0056] As shown in Figures 2 to 4, the first pressing member 66 has a plurality of first holes 122 formed therein. Each of the plurality of first holes 122 penetrates the first pressing member 66 in the axial direction.

[0057] As shown in Figure 8, the second pressing member 68 has a plurality of second holes 124 formed therein. Each of the plurality of second holes 124 penetrates the second pressing member 68 in the axial direction.

[0058] As shown in Figures 2 to 4, a hollow portion 126 is formed inside each of the multiple blades 70. The hollow portion 126 opens into the first end wall 72. The multiple first holes 122 of the first pressing member 66 are formed in the first pressing member 66 at circumferential intervals so as to face the hollow portions 126 of the multiple blades 70. Each of the multiple first holes 122 is larger than each of the multiple second holes 124.

[0059] As shown in Figure 8, the multiple second holes 124 are formed in the second pressing member 68 so as to surround each of the multiple blades 70 when viewed from the axial direction.

[0060] As shown in Figures 2 to 4, each of the multiple blades 70 has multiple first communication holes 128 that communicate with the outside and inside (hollow portion 126) of the blade 70. In addition, each of the multiple blades 70 has multiple second communication holes 130 formed in the second divided annular portion 84. The multiple second communication holes 130 are formed axially so as to avoid the hollow portion 126.

[0061] As shown in Figures 3 and 5 to 7, a first insertion groove 132 is formed in each of the multiple first dividing surfaces 86 (see Figures 3 and 4). The first insertion groove 132 is a groove that is recessed in the circumferential direction from the first dividing surface 86. The first insertion groove 132 extends along the first dividing surface 86 from the outer circumference to the inner circumference of the first divided annular portion 82. Specifically, the radially outer side (outer end) of the first insertion groove 132 is open. The radially inner side (inner end) of the first insertion groove 132 is closed. A plate-shaped first sealing member 136 is inserted into the first insertion groove 132.

[0062] A second insertion groove 134 is formed in each of the multiple second dividing surfaces 88. The second insertion groove 134 is a groove that is recessed in the circumferential direction from the second dividing surface 88. The second insertion groove 134 extends along the second dividing surface 88 from the outer circumference to the inner circumference of the second divided annular portion 84. Specifically, the radially outer side (outer end) of the second insertion groove 134 is open. The radially inner side (inner end) of the second insertion groove 134 is closed. A plate-shaped second sealing member 138 is inserted into the second insertion groove 134.

[0063] In adjacent segments 80, a portion of the first sealing member 136 is inserted into one of the opposing first insertion grooves 132, and the other portion of the first sealing member 136 is inserted into the other opposing first insertion groove 132. That is, one end of the first sealing member 136 along the circumferential direction is inserted into the first insertion groove 132 of one segment 80. The other end of the first sealing member 136 along the circumferential direction is inserted into the first insertion groove 132 of the other segment 80.

[0064] In adjacent segments 80, a portion of the second seal member 138 is inserted into one of the two opposing second insertion grooves 134, and the other portion of the second seal member 138 is inserted into the other of the two opposing second insertion grooves 134. That is, one end of the second seal member 138 along the circumferential direction is inserted into the second insertion groove 134 of one segment 80. The other end of the second seal member 138 along the circumferential direction is inserted into the second insertion groove 134 of the other segment 80.

[0065] Therefore, the space between two adjacent segments 80 is sealed by the first sealing member 136 and the second sealing member 138.

[0066] As shown in Figures 3 to 7, a first outer peripheral groove 140 is formed on the outer circumference of the first ring 62. The first outer peripheral groove 140 is recessed radially inward on the outer circumference of the first ring 62. The first outer peripheral groove 140 extends in an annular shape circumferentially on the outer circumference of the first ring 62. An annular seal ring 50 (see Figures 1 and 5 to 7) is inserted into the first outer peripheral groove 140.

[0067] A second outer circumferential groove 142 is formed on the outer circumferential portion of the second ring 64. The second outer circumferential groove 142 is radially formed on the outer circumferential portion of the second ring 64. outside It is recessed on the side. The second outer circumferential groove 142 extends in an annular shape in the circumferential direction on the outer circumferential portion of the second ring 64. An annular seal ring 52 (see Figures 1 and 5-7) is inserted into the second outer circumferential groove 142.

[0068] The inner circumference of the nozzle body 60 can be seated on the first holder 34. Furthermore, the multiple segments 80 are movable in the radial direction.

[0069] Specifically, as shown in Figures 3 to 5, a fitting projection 144 is formed on the inner circumference of the first divided annular portion 82 for each of the multiple segments 80. The fitting projection 144 protrudes radially inward from the inner circumference of the first divided annular portion 82. Multiple slots 146 are formed in the first holder 34. The multiple slots 146 are formed at intervals from each other in the circumferential direction so as to face the fitting projections 144 of the multiple segments 80. Each of the multiple fitting projections 144 is inserted into one of the multiple slots 146.

[0070] The first holder 34 is in axial surface contact with the first projection 92. The outer circumference of the second holder 36 is in axial surface contact with the second projection 100.

[0071] As shown in Figure 6, immediately after the radial turbine nozzle 10 is assembled to the gas turbine 12, a clearance 148 is provided between the inner circumference of each first segmented annular portion 82 of the multiple segments 80 and the first holder 34. A clearance 150 is provided between the inner circumference of the second segmented annular portion 84 and the second holder 36.

[0072] The operation of the gas turbine 12, configured as described above, will now be explained.

[0073] As shown in Figure 1, the compressor wheel 22 takes in air from the outside and compresses it. The compressed air is supplied to the gas flow passage 40 via the diffuser 24. The gas flow passage 40 supplies the compressed air to the combustor 26. The fuel supply nozzle 44 supplies fuel to the combustor 26. The combustor 26 generates combustion gas by mixing the fuel supplied from the fuel supply nozzle 44 with the compressed air and burning it. The combustion gas is supplied to the radial turbine nozzle 10 via the outlet 48.

[0074] The combustion gases collide with the multiple blades 70 radially inward. As shown in Figures 2, 3, and 8, the multiple blades 70 are inclined at a predetermined angle with respect to the radial direction. Therefore, the multiple blades 70 convert the direction of flow of the combustion gases to a direction along the predetermined angle. The combustion gases, whose direction of flow has been converted, pass between the multiple blades 70 and are injected into the radial turbine 18 (see Figure 1). The injected combustion gases collide with the blades of the radial turbine 18, causing the radial turbine 18 to rotate. As a result, the radial turbine 18, shaft 16, and rotating shaft rotate together, and the rotating electric machine generates electricity. The combustion gases that have passed through the radial turbine 18 are discharged to the outside through the outlet 54 of the gas discharge section 28.

[0075] As shown in Figures 3 and 4, cooling gas such as air taken in from the outside is supplied to multiple hollow sections 126 through multiple first holes 122. This allows for efficient cooling of multiple first segmented annular sections 82 and multiple blades 70. The cooling gas supplied to the hollow sections 126 passes through multiple first communication holes 128 formed in the blades 70 and is discharged to the outside from the outlet 54 (see Figure 1) of the gas discharge section 28 together with the combustion gas.

[0076] As shown in Figures 4 and 8, cooling gas such as air taken in from the outside is supplied to the space between the second pressing member 68 and the second divided annular portion 84 through a plurality of second holes 124. This allows for efficient cooling of the plurality of second divided annular portions 84. The cooling gas supplied to this space passes through a plurality of second communication holes 130 formed in the second divided annular portion 84 and is discharged to the outside from the outlet 54 (see Figure 1) of the gas discharge section 28 together with the combustion gas.

[0077] Next, the assembly method of the radial turbine nozzle 10 and the method of attaching the radial turbine nozzle 10 to the gas turbine 12 will be explained with reference to Figures 9 to 11B.

[0078] First, the assembly method of the radial turbine nozzle 10 will be explained with reference to the flowchart in Figure 9 and Figures 10 to 11B.

[0079] In this assembly method, a sliding jig 162 (see Figure 10) may be used. When using the sliding jig 162, in step S1 of Figure 9, the sliding jig 162 is placed in the center of the plate-shaped base jig 160. In Figure 10, only the outer periphery of the sliding jig 162 is shown by a dashed line. Multiple pressing parts 164 capable of pressing the inner periphery of multiple segments 80 are formed on the outer periphery of the sliding jig 162.

[0080] Next, in step S2 (first ring placement step) in Figure 9, the first ring 62 is placed on the upper surface of the base jig 160 (see Figure 10). The first ring 62 is placed on the upper surface of the base jig 160 through the sliding jig 162.

[0081] In the next step S3 (first pressing member placement step), the first pressing member 66 is placed on the first ring 62. The first pressing member 66 is placed on the first ring 62 through the sliding jig 162.

[0082] In the next step S4 (first flange insertion step), a portion of the first flange portion 90 (one circumferential end of the first flange portion 90) of each of the multiple segments 80 is inserted into the first outer groove 76 of the first ring 62. Note that for each of the multiple segments 80, a first seal member 136 is pre-inserted into one of the first insertion grooves 132, and a second seal member 138 is pre-inserted into one of the second insertion grooves 134. In this case, the other circumferential end of the first flange portion 90 is positioned radially inward from the one circumferential end of the first flange portion 90. Therefore, the other circumferential end of the first flange portion 90 is not inserted into the first outer groove 76. As a result, each of the multiple segments 80 is positioned between the first flange portion 90 and the outer surface of the sliding jig 162 with the first seal member 136 and the second seal member 138 pre-inserted. Furthermore, each of the multiple segments 80 is arranged such that two adjacent segments 80 in the circumferential direction are spaced apart from each other.

[0083] In the next step S5 (second pressing member placement step), the second pressing members 68 are placed for multiple segments 80.

[0084] In the next step S6 (second flange insertion step), the second flange portion 98 is positioned for each of the multiple segments 80 by inserting a part of the second flange portion 98 (one circumferential end of the second flange portion 98) into the second outer groove 78 of the second ring 64. In this case, the other circumferential end of the second flange portion 98 is positioned radially inward from the one circumferential end of the second flange portion 98. Therefore, the other circumferential end of the second flange portion 98 is not inserted into the second outer groove 78.

[0085] In the next step S7, first, the bolt 166 is attached to the base jig 160. Next, the pressing jig 168 is inserted onto the bolt 166. The pressing jig 168 contacts the second ring 64. Next, the nut 170 is attached to the bolt 166. Then, by moving the nut 170 to a predetermined position on the bolt 166, a force is applied to the first ring 62, the first pressing member 66, the multiple segments 80, the second pressing member 68, and the second ring 64 along the axial direction of the bolt 166. As a result, the first ring 62, the first pressing member 66, the multiple segments 80, the second pressing member 68, and the second ring 64 are held in that axial direction. The axial direction of the bolt 166 is the same as the axial direction of the sliding jig 162 and coincides with the axial direction of the nozzle body 60 (the axial direction of the radial turbine 18).

[0086] In the next step S8 (segment connection step), the multiple segments 80 are connected in the circumferential direction by rotating each of the multiple segments 80 and sliding them radially outward of the first ring 62. For example, when using a sliding jig 162, the sliding jig 162 is rotated around its axis. As a result, the multiple pressing parts 164 of the sliding jig 162 press the inner circumferential portions of the multiple segments 80 radially outward of the sliding jig 162. As a result, each of the multiple segments 80 slides radially outward. At this time, the first dividing surfaces 86 of two adjacent segments 80 in the circumferential direction of the sliding jig 162 overlap, and their second dividing surfaces 88 also overlap. As a result, the multiple segments 80 are connected in the circumferential direction of the sliding jig 162, and the nozzle body 60 is formed.

[0087] The segment connection process will now be explained in more detail. As the sliding jig 162 rotates, the multiple segments 80 move radially outward from the state shown in Figure 11A. As the sliding jig 162 rotates further, each of the multiple segments 80 rotates radially outward, pivoting on the corner 172 of the outer circumference of the first segmented annular portion 82 (one end of the first flange portion 90 in the circumferential direction) and the corner 173 of the outer circumference of the second segmented annular portion 84 (one end of the second flange portion 98 in the circumferential direction). As a result, as shown in Figure 11B, the entire circumferential length of the first flange portion 90 is inserted into the first outer groove 76, and the entire circumferential length of the second flange portion 98 is inserted into the second outer groove 78. Consequently, the first segmented surfaces 86 of two circumferentially adjacent segments 80 overlap each other, and their second segmented surfaces 88 also overlap. Furthermore, for two circumferentially adjacent segments 80, a first sealing member 136 is inserted into the first insertion groove 132 facing each other, and a second sealing member 138 is inserted into the second insertion groove 134 (see Figure 3) facing each other. As a result, the space between two circumferentially adjacent segments 80 is sealed by the first sealing member 136 and the second sealing member 138. In this way, the two circumferentially adjacent segments 80 are connected.

[0088] As described above, with a clearance between two adjacent segments 80, a portion of the segment 80 is inserted into the first ring 62 and the second ring 64, and the segment 80 is rotated using the corner 172 of the outer circumference of the first divided annular portion 82 and the corner 173 of the outer circumference of the second divided annular portion 84 as pivot points. This allows multiple segments 80 to be connected easily and stably.

[0089] Furthermore, in step S8, as the multiple segments 80 are connected in the circumferential direction of the sliding jig 162, the inner circumference 108 of the first pressing member 66 is inserted into the first inner groove 94, and the inner circumference 112 of the second pressing member 68 is inserted into the second inner groove 102. As a result, each of the multiple segments 80 is positioned in the axial direction of the nozzle body 60.

[0090] Furthermore, in step S8, as the multiple segments 80 are connected in the circumferential direction of the sliding jig 162, the first projection 116 of the first pressing member 66 is inserted into the first notch 114, and the second projection 120 of the second pressing member 68 is inserted into the second notch 118. As a result, each of the multiple segments 80 is positioned in the circumferential direction of the nozzle body 60. This makes it possible to align the circumferential phase of the hollow portions 126 of the multiple segments 80 with the multiple first holes 122.

[0091] In this way, the radial turbine nozzle 10 is constructed.

[0092] In the next step, S9, first, the nut 170 is loosened to release the radial turbine nozzle 10 from the pressed position. Next, the nut 170 is removed from the bolt 166, and the pressing jig 168 is removed from the bolt 166. Then, the radial turbine nozzle 10 is removed from the base jig 160.

[0093] Next, we will explain how to assemble the radial turbine nozzle 10 to the gas turbine 12.

[0094] In this assembly method, in step S10 (nozzle placement step), the radial turbine nozzle 10 assembled in each of the steps S1 to S9 (nozzle assembly steps) is placed radially outward on the first holder 34. Specifically, the radial turbine nozzle 10 is placed on the first holder 34 and the second holder 36 such that the inner circumference portion of the nozzle body 60 can seat on the first holder 34 and the multiple segments 80 can move radially. The radial turbine nozzle 10 is placed with radial clearances of 148 and 150 relative to the first holder 34 and the second holder 36.

[0095] The inner circumferential portions of the multiple segments 80 are seated on the first holder 34 by the pressure of the combustion gases during operation of the gas turbine 12. Specifically, when the combustion gases collide with the multiple blades 70, a radially inward pressing force acts on each of the multiple segments 80. As a result, each of the multiple segments 80 moves radially inward. Consequently, as shown in Figure 7, the inner circumferential portion of the first divided annular portion 82 of each of the multiple segments 80 is seated on the first holder 34. As a result, the radial turbine nozzle 10 is positioned and fixed radially to the radial turbine 18.

[0096] In the above description, the case in which the first sealing member 136 is inserted into the first insertion groove 132 and the second sealing member 138 is inserted into the second insertion groove 134 was described. In this embodiment, it is sufficient that the first sealing member 136 and the second sealing member 138 can be held between two adjacent segments 80. Therefore, in this embodiment, the first sealing member 136 may be inserted into slots (recesses) formed in a plurality of first dividing surfaces 86. Alternatively, the second sealing member 138 may be inserted into slots (recesses) formed in a plurality of second dividing surfaces 88.

[0097] Furthermore, in the radial turbine nozzle assembly method shown in Figure 9, the sliding jig 162 may not be used, and the multiple segments 80 may be connected in the circumferential direction by having an operator manually move the multiple segments 80 radially outward.

[0098] The inventions that can be understood from the above embodiments are described below.

[0099] A first aspect of the present invention is a gas turbine (12) comprising a radial turbine (18), a radial turbine nozzle (10) surrounding the radial turbine, and a holding portion (34) for holding the radial turbine nozzle, wherein the radial turbine nozzle comprises a plurality of blades (70) arranged at predetermined intervals in the circumferential direction of the radial turbine, an annular nozzle body (60) having a first end wall (72) connected to one end of the plurality of blades in the axial direction of the radial turbine, and a second end wall (74) connected to the other end of the plurality of blades in the axial direction, a first ring (62) surrounding the first end wall, and a second ring (64) surrounding the second end wall, wherein the nozzle body has a plurality of segments (80) connected along the circumferential direction, and the first ring is recessed outward in the radial direction of the radial turbine and extends in the circumferential direction. The nozzle body has a first outer groove (76), the second ring has a second outer groove (78) that is recessed radially outward and extends circumferentially, each of the plurality of segments has a first divided annular portion (82) formed by dividing the first end wall with a plurality of first dividing surfaces (86) inclined radially, and a second divided annular portion (84) formed by dividing the second end wall with a plurality of second dividing surfaces (88) inclined radially, the outer circumferential portion of the first divided annular portion has a first flange portion (90) projecting radially outward, the first flange portion is inserted into the first outer groove, the outer circumferential portion of the second divided annular portion has a second flange portion (98) projecting radially outward, the second flange portion is inserted into the second outer groove, the inner circumferential portion of the nozzle body can seat on the holding portion, and the plurality of segments are movable radially.

[0100] According to the present invention, during gas turbine operation, the inner circumference of the nozzle body is seated on the holding part by the pressure of the combustion gas passing through the radial turbine nozzle. During gas turbine operation, the holding part is at a lower temperature than the radial turbine nozzle. Therefore, the holding part experiences less dimensional change due to thermal expansion. This allows the radial turbine nozzle assembled to the gas turbine to be precisely positioned and fixed. Furthermore, the first and second dividing surfaces are inclined with respect to the radial direction of the radial turbine. This makes it possible to easily move multiple segments in the radial direction of the radial turbine when the combustion gas passes through the radial turbine nozzle. In addition, the clearance between the holding part and the radial turbine nozzle allows the radial turbine nozzle to be easily assembled to the gas turbine.

[0101] In a first embodiment of the present invention, a first insertion groove (132) is formed in each of the plurality of first dividing surfaces, a second insertion groove (134) is formed in each of the plurality of second dividing surfaces, a first sealing member (136) is inserted into the first insertion groove, and a second sealing member (138) is inserted into the second insertion groove.

[0102] Since the first and second sealing members do not press against the multiple segments, the combustion gas pressure makes it possible to easily move the multiple segments radially inward of the radial turbine.

[0103] A second aspect of the present invention is a method for assembling a radial turbine nozzle, the radial turbine nozzle comprising: a plurality of blades arranged at predetermined intervals in the circumferential direction of a radial turbine; an annular nozzle body having a plurality of blades arranged at predetermined intervals in the circumferential direction of the radial turbine; a first end wall connected to one end of the plurality of blades in the axial direction of the radial turbine; a second end wall connected to the other end of the plurality of blades in the axial direction; a first ring surrounding the first end wall; and a second ring surrounding the second end wall, wherein the nozzle body has a plurality of segments connected along the circumferential direction; the first ring has a first outer groove recessed outward in the radial direction of the radial turbine and extending in the circumferential direction; the second ring has a second outer groove recessed outward in the radial direction and extending in the circumferential direction; and each of the plurality of segments has a plurality of first divisions inclined with respect to the radial direction of the first end wall The nozzle comprises a first divided annular portion formed by dividing it with a surface, and a second divided annular portion formed by dividing the second end wall with a plurality of second dividing surfaces inclined with respect to the radial direction, wherein the outer circumferential portion of the first divided annular portion has a first flange portion projecting outward in the radial direction, and the first flange portion is inserted into the first outer groove, and the outer circumferential portion of the second divided annular portion has a second flange portion projecting outward in the radial direction, and the second flange portion is inserted into the second outer groove, and the assembly method comprises a nozzle assembly step of assembling the radial turbine nozzle with the first ring and the second ring assembled to the outer circumferential portion of the nozzle body, and a nozzle arrangement step of positioning the radial turbine nozzle on the radial side of the holding portion such that the inner circumferential portion of the nozzle body can be seated against the holding portion of the gas turbine and the plurality of segments can move in the radial direction.

[0104] According to the present invention, during gas turbine operation, the inner circumference of the nozzle body is seated on the holding part by the pressure of the combustion gas passing through the radial turbine nozzle. During gas turbine operation, the holding part is at a lower temperature than the radial turbine nozzle. Therefore, the holding part experiences less dimensional change due to thermal expansion. This allows the radial turbine nozzle assembled to the gas turbine to be precisely positioned and fixed. Furthermore, the first and second dividing surfaces are inclined with respect to the radial direction of the radial turbine. This makes it possible to easily move multiple segments in the radial direction of the radial turbine when the combustion gas passes through the radial turbine nozzle. In addition, the clearance between the holding part and the radial turbine nozzle allows the radial turbine nozzle to be easily assembled to the gas turbine.

[0105] Furthermore, the present invention is not limited to the disclosure described above, and can take various configurations without departing from the spirit of the invention. [Explanation of Symbols]

[0106] 10…Radial turbine nozzle 12…Gas turbine 18...Radial turbine 34...First holder (holding part) 60...Nozzle body 62...First ring 64...Second Ring 70...Blade 72...First end wall 74...Second end wall 76...First outer groove 78...Second outer groove 80...Segment 82...First divided annular section 84...Second division ring section 86...First division surface 88...Second dividing surface 90...First flange section 98...Second flange section

Claims

1. A gas turbine comprising a radial turbine, a radial turbine nozzle surrounding the radial turbine, and an annular holding portion for holding the radial turbine nozzle, The radial turbine nozzle is An annular nozzle body having a plurality of blades arranged at predetermined intervals in the circumferential direction of the radial turbine, a first end wall connected to one end of the plurality of blades in the axial direction of the radial turbine, and a second end wall connected to the other end of the plurality of blades in the axial direction, The first ring surrounding the first end wall, The second ring surrounding the second end wall, Equipped with, The nozzle body has a plurality of segments connected along the circumferential direction, The first ring has a first outer groove that is recessed radially outward of the radial turbine and extends in the circumferential direction, The second ring has a second outer groove that is recessed radially outward and extends circumferentially, Each of the above-mentioned segments is A first divided annular portion is formed by dividing the first end wall with a plurality of first dividing surfaces inclined with respect to the radial direction, A second divided annular portion is formed by dividing the second end wall with a plurality of second dividing surfaces inclined with respect to the radial direction, It has, The outer circumferential portion of the first divided annular section has a first flange portion that protrudes radially outward, and the first flange portion is inserted into the first outer groove. The outer circumferential portion of the second divided annular portion has a second flange portion that protrudes radially outward, and the second flange portion is inserted into the second outer groove. The inner circumference of the first divided annular portion is loosely fitted to the outer circumference of the retaining portion. The plurality of segments are movable in the radial direction, forming a gas turbine.

2. In the gas turbine according to claim 1, A first insertion groove is formed in each of the plurality of first dividing surfaces. A second insertion groove is formed in each of the plurality of second dividing surfaces. A first sealing member is inserted into the first insertion groove. A gas turbine in which a second sealing member is inserted into the second insertion groove.

3. In the gas turbine according to claim 1 or 2, In each of the plurality of segments, a fitting projection is formed on the inner circumference of the first divided annular portion. Multiple slots are formed on the outer circumference of the holding portion at intervals in the circumferential direction. A gas turbine in which the plurality of fitting protrusions are each inserted into the plurality of slots.

4. A method for assembling a radial turbine nozzle, The radial turbine nozzle is An annular nozzle body having a plurality of blades arranged at predetermined intervals in the circumferential direction of a radial turbine, a first end wall connected to one end of the plurality of blades in the axial direction of the radial turbine, and a second end wall connected to the other end of the plurality of blades in the axial direction, The first ring surrounding the first end wall, The second ring surrounding the second end wall, Equipped with, The nozzle body has a plurality of segments connected along the circumferential direction, The first ring has a first outer groove that is recessed radially outward of the radial turbine and extends in the circumferential direction, The second ring has a second outer groove that is recessed radially outward and extends circumferentially, Each of the above-mentioned segments is A first divided annular portion is formed by dividing the first end wall with a plurality of first dividing surfaces inclined with respect to the radial direction, A second divided annular portion is formed by dividing the second end wall with a plurality of second dividing surfaces inclined with respect to the radial direction, It has, The outer circumferential portion of the first divided annular section has a first flange portion that protrudes radially outward, and the first flange portion is inserted into the first outer groove. The outer circumferential portion of the second divided annular portion has a second flange portion that protrudes radially outward, and the second flange portion is inserted into the second outer groove. The aforementioned assembly method is A nozzle assembly step in which the radial turbine nozzle is assembled with the first ring and the second ring attached to the outer circumference of the nozzle body, A nozzle arrangement step is to position the radial turbine nozzle on the radially outside the holding portion such that the inner circumference of the first divided annular portion is loosely fitted to the outer circumference of the annular holding portion of the gas turbine, and the plurality of segments are movable in the radial direction. A method for assembling a radial turbine nozzle, comprising [the specified element].

Images