Transition parts, combustors and gas turbine engines

Abstract

The present invention is a transition part, a combustor, and a gas turbine engine that suppress stress near the dilution holes of the transition part. A transition part is provided, which comprises: a first flow path group formed by arranging a plurality of in-wall flow paths extending from a gas turbine side to a combustor liner side inside a plate constituting the transition part; a second flow path group located on a combustor liner side relative to the first flow path group; and a plurality of dilution holes that penetrate the plate and connect a compressed air main flow path and a combustion gas flow path, wherein each in-wall flow path of the first flow path group and the second flow path group has an inlet facing the compressed air main flow path at an end portion on a gas turbine side and an outlet facing the combustion gas flow path at an end portion on a combustor liner side, and the dilution holes are located at a position closer to the inlet of the in-wall flow path of the second flow path group than to the outlet of the in-wall flow path of the second flow path group in each space between adjacent in-wall flow paths of the second flow path group.

Description

Technical Field

[0001] The invention relates to a transition piece, a combustor and a gas turbine engine. Background Art

[0002] The gas turbine engine burns fuel together with compressed air compressed by a compressor in a combustor, and uses the combustion gas generated thereby to drive the gas turbine. A plurality of combustors are arranged in the circumferential direction of the casing of the gas turbine engine, and the combustion gas is supplied to the gas turbine via a transition part formed into a cylindrical shape from a metal plate in each combustor.

[0003] In a combustor, when the amount of fuel is low, there is a case where the amount of compressed air supplied to the burner is excessive, the combustion temperature is reduced, and the combustion stability is reduced. From the viewpoint of suppressing the reduction of the combustion stability, there is a combustor in which air holes called dilution holes are provided in the transition part (Patent Document 1, etc.). By allowing a part of the compressed air to flow into the combustion gas flow path inside the transition part through the dilution hole, it is possible to suppress the reduction in the flow rate of the working medium supplied to the gas turbine and suppress the excessive supply of compressed air to the burner.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent document: Japanese Patent Application Publication No. 2010-25543 Summary of the invention

[0007] Problems to be solved by the invention

[0008] If air is supplied to a place where the combustion reaction of the flame is not fully carried out, the flame temperature will decrease. Therefore, the dilution hole of the transition part is set at the place where the combustion reaction of the flame is fully carried out. However, the area where the combustion reaction of the flame is fully carried out is a harsh high-temperature environment. In particular, the transition part is a structure in which the cross-sectional shape gradually changes from a circular inlet to a quadrilateral outlet according to the shape of the burner liner, and the curvature varies greatly depending on the location. Therefore, when the dilution hole is set on the transition part, the stress near the dilution hole in the transition part is likely to increase.

[0009] An object of the present invention is to provide a transition part, a combustor, and a gas turbine engine capable of suppressing stress in the vicinity of a dilution hole.

[0010] Solutions to Solve Problems

[0011] 14. The burner engine of claim 13 wherein the burner engine is configured to have a plurality of vents, each of which is configured to have a plurality of vents, each of which is configured to have a plurality of vents, each of which is configured to have a plurality of vents, each of which is configured to have a plurality of vents, each of which is configured to have a plurality of vents, each of which is configured to have a plurality of vents, each of which is configured to have a plurality of vents, each of which is configured to have a plurality of vents, each of which is configured to have a plurality of vents, each of which is configured to have a plurality of vents, each of which is configured to have a plurality of vents, each of which is configured to have a plurality of vents, each of which is configured to have a plurality of vents, each of which is configured to have a plurality of vents, each of which is configured to have a plurality of vents, each of which is configured to have a plurality of vents, each of which is configured to have a plurality of vents The in-wall flow paths of the first flow path group and the second flow path group are located on a side close to the combustor liner and are formed by arranging a plurality of in-wall flow paths extending from a side close to the gas turbine to a side close to the combustor liner in the plate in the circumferential direction of the transition part; and a plurality of dilution holes that penetrate the plate and connect the compressed air main flow path with the combustion gas flow path, wherein each in-wall flow path of the first flow path group and the second flow path group has an inlet facing the compressed air main flow path at an end portion on a side close to the gas turbine, and has an outlet facing the combustion gas flow path at an end portion on a side close to the combustor liner, and in each space between adjacent in-wall flow paths of the second flow path group, the dilution hole is located at a position closer to the inlet of the in-wall flow paths of the second flow path group than to the outlet of the in-wall flow paths of the second flow path group.

[0012] Effects of the Invention

[0013] According to the present invention, stress in the vicinity of the dilution hole of the transition part can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic configuration diagram schematically showing an example of a gas turbine facility including a transition part according to an embodiment of the present invention.

[0015] Figure 2 It is a perspective view of a transition part according to one embodiment of the present invention.

[0016] Figure 3 This is a schematic diagram of a cross section of a transition part according to an embodiment of the present invention cut along a plane passing through the center line of a gas turbine.

[0017] Figure 4 is a schematic representation of the Figure 3 A directional view of a portion of the outer peripheral surface of a transition part of one embodiment of the present invention, viewed in the direction of arrow IV.

[0018] Figure 5 yes Figure 4 Sectional view along line VV in the figure.

[0019] Figure 6 yes Figure 4 Sectional view along line VI-VI.

[0020] Figure 7 yes Figure 4 Cross-sectional view along line VII-VII.

[0021] Figure 8 It is a schematic diagram showing the region where the flow path in the wall of the back side portion of the transition component according to one embodiment of the present invention is provided.

[0022] Fig. 9 It is a schematic diagram showing the region where the in-wall flow path is provided in the side portion of the transition component according to one embodiment of the present invention.

[0023] Fig.10 It is a schematic diagram showing the region where the in-wall flow path is provided in the belly side portion of the transition part according to one embodiment of the present invention.

[0024] Description of Reference Numerals

[0025] 10…compressor, 20…combustor, 21…combustor liner, 23…transition part, 23a…combustion gas flow path, 25…plate material, 26-28…inner wall flow path, 26a, 27a, 28a…inlet, 26b, 27b, 28b…outlet, 26G…first flow path group, 27G…second flow path group, 29…dilution hole, 30…gas turbine, 100…gas turbine engine, 101a…main flow path of compressed air, a…compressed air, d…distance between the outlet of the inner wall flow path and the dilution hole, D…interval of the inner wall flow path, g…combustion gas, OL1, OL2…overlapping portion, W…diameter of the inner wall flow path. DETAILED DESCRIPTION

[0026] Hereinafter, embodiments of the present invention will be described using the drawings.

[0027] - Gas turbine engine -

[0028] Figure 1 1 is a schematic structural diagram schematically showing an example of a gas turbine plant equipped with a transition part according to an embodiment of the present invention. The gas turbine plant shown in the figure is configured to include a gas turbine engine 100 and a load device 200 driven by the gas turbine engine 100. A typical example of the load device 200 is a generator, but there is also a case where a pump or a compressor (a device different from the compressor 10 provided in the gas turbine engine 100) is used as the load device 200 instead of the generator, and the gas turbine engine 100 drives these compressors and pumps.

[0029] The gas turbine engine 100 is a prime mover for driving the load device 200, and is configured to include a compressor 10, a combustor 20, and a gas turbine 30. The compressor 10 is configured to suck in air and compress it to generate high-temperature and high-pressure compressed air a. The combustor 20 is configured to combust fuel together with the compressed air a discharged from the compressor 10 via the diffuser 11 to generate combustion gas g. The gas turbine 30 is driven by the combustion gas g supplied from the combustor 20 to output rotational power. The shafts of the rotors of the gas turbine 30 and the compressor 10 are connected. A part of the output of the gas turbine 30 is used as the power of the compressor 10, and the remaining part is used as the power of the load device 200. The combustion gas g after driving the gas turbine 30 is discharged as exhaust gas through an exhaust chamber (not shown).

[0030] In the present embodiment, the case where the gas turbine engine 100 is a single-shaft type is exemplified, but the gas turbine engine 100 may be a dual-shaft type. In the case of a dual-shaft gas turbine engine, the gas turbine 30 is composed of a high-pressure turbine and a low-pressure turbine whose rotating shafts are separated from each other, the high-pressure turbine is coaxially connected to the compressor 10, and the low-pressure turbine is coaxially connected to the load device 200.

[0031] - Burner -

[0032] The combustor 20 is installed in a plurality of positions (in the direction of rotation of the gas turbine 30) with respect to the engine room (casing) 101 of the gas turbine engine 100. Figure 1 In the figure, only one burner 20 is shown as a representative. Each burner 20 is configured to include a burner liner 21, a burner nozzle 22, and a transition part 23. The burner 20 causes the fuel ejected from the burner nozzle 22 to burn together with the compressed air a compressed by the compressor 10 in the interior (combustion chamber 21a) of the burner liner 21 to generate combustion gas g, and supplies the combustion gas g to the gas turbine 30 via the transition part 23.

[0033] The combustor liner 21 is a cylindrical member having a combustion chamber 21a formed inside, and is provided inside the engine room 101. The combustor liner 21 separates the compressed air a introduced from the compressor 10 into the engine room 101 (in other words, the compressed air main flow path 101a outside the combustor liner 21) from the combustion gas g generated in the combustion chamber 21a (in other words, the combustion chamber 21a inside the combustor liner 21). A transition part 23 is inserted into the end of the combustor liner 21 on the gas turbine side (right side in the figure).

[0034] The burner 22 is a device that injects fuel into the combustion chamber 21a via at least one fuel nozzle 22a to form and maintain flames inside the combustion chamber 21a. Fuel from a fuel source (eg, a fuel tank) is supplied to the fuel nozzle 22a via a fuel system (fuel piping) 22b.

[0035] Next, the structure of the transition part 23 will be described.

[0036] -Transition parts-

[0037] Figure 2 It is a three-dimensional diagram of the transition part. Figure 3 Schematic diagram of a cross section of a transition part obtained by cutting with a plane passing through the center line of the gas turbine 30. Figure 2 In the figure, the wall flow passages 26 to 28 and the dilution holes 29 (described later) are omitted.

[0038] The transition part 23 is a component that guides the combustion gas g generated in the combustion chamber 21a to the gas turbine 30, connects the combustor liner 21 to the gas turbine 30, and is formed into a cylindrical shape by a metal (alloy) plate (transition part plate) 25. The transition part 23 separates the outer compressed air main flow path 101a through which the compressed air a supplied from the compressor 10 to the burner nozzle 22 of the combustor 20 flows, and the inner combustion gas flow path 23a through which the combustion gas g supplied from the combustor liner 21 to the gas turbine 30 flows. As described above, the combustor liner 21 is inserted into the end of the transition part 23 on the combustor liner side, that is, the inlet 23b of the combustion gas g. The end of the transition part 23 on the gas turbine side, that is, the outlet 23c of the combustion gas g faces the inlet 30a ( Figure 1 The combustion gas g is supplied from the outlet 23 c of the transition part 23 to an annular working fluid flow path facing the stationary blades (not shown) and the moving blades (not shown) in the gas turbine 30 .

[0039] The inlet 23b of the transition part 23 is formed according to the cylindrical shape of the combustor liner 21 ( Figure 1 )’s outlet shape, such as Figure 2 The transition part 23 is formed in a circular shape as shown. On the other hand, the outlet 23c of the transition part 23 is formed in a quadrilateral shape according to the shape of the inlet 30a of the annular working fluid flow path of the gas turbine 30 being equally divided by the number of the burners 20 in the rotation direction of the gas turbine 30. The outlets 23c of the transition parts 23 of the plurality of burners 20 provided in the gas turbine engine 100 are connected in the rotation direction of the gas turbine 30 and are annular in shape according to the shape of the inlet 30a of the gas turbine 30. Therefore, the cross-sectional shape of the transition part 23 gradually changes from the circular inlet 23b toward the quadrilateral outlet 23c, and the curvature of the plate 25 constituting the transition part 23 is different depending on the location.

[0040] For example, when the transition part 23 is viewed from the back side, the width (dimension in the rotation direction of the gas turbine 30) of the transition part 23 changes as the inlet 23b approaches the outlet 23c, and the width of the outlet 23c becomes wider than the width of the inlet 23b ( Figure 8 On the other hand, when the transition part 23 is viewed from the side, the width of the transition part 23 (the dimension in the radial direction of the gas turbine 30) becomes narrower as the distance from the inlet 23b to the outlet 23c is approached ( Figure 3 ). Thus, the curvature of the plate 25 constituting the transition part 23 varies depending on the position in the flow direction of the combustion gas g and further on the circumferential position of the transition part 23. The shape of the transition part 23 is smooth from the perspective of guiding the combustion gas g, but it is complicated.

[0041] It should be noted that the back side of the transition part 23 refers to the outer side of the transition part 23 in the radial direction of the gas turbine 30. Therefore, the inner side of the transition part 23 in the radial direction of the gas turbine 30 is the belly side of the transition part 23. In addition, viewing the transition part 23 from the side means viewing the transition part 23 from the direction along the rotation direction of the gas turbine 30.

[0042] In this embodiment, if Figure 3 As shown in FIG. 1 , each transition part 23 is provided with a plurality of wall flow paths 26-28 and a plurality of dilution holes 29. It should be noted that, regarding the plurality of dilution holes 29, in the example shown in the figure, a structure is shown in which two annular rows of dilution holes are formed in the circumferential direction of the transition part 23, but the number of rows may be one or more than three. An appropriate number of rows is selected from the viewpoint of combustion stability. The wall flow paths 26-28 and the dilution holes 29 are described in sequence below.

[0043] -Intra-wall flow path-

[0044] Figure 4 is a schematic representation of the Figure 3 A view of a portion of the outer peripheral surface of the transition part observed in the direction of arrow IV, Figure 5 yes Figure 4 The cross-sectional view along the VV line in the figure, Figure 6 yes Figure 4 The cross-sectional view along the VI-VI line in the figure, Figure 7 yes Figure 4 Cross-sectional view along line VII-VII. Figure 8 It is a schematic diagram showing the region where the flow path in the wall of the back side portion of the transition component is provided. Fig. 9 It is a schematic diagram showing the installation area of ​​the in-wall flow path of the side portion of the transition part. Fig.10It is a schematic diagram showing the region where the flow path in the wall of the belly side portion of the transition part is provided.

[0045] The transition part 23 includes a first flow path group 26G, a second flow path group 27G, and a third flow path group 28G. The first flow path group 26G is a collection of flow paths formed into an annular shape by arranging a plurality of in-wall flow paths 26 in the circumferential direction of the transition part 23, and surrounds the transition part 23. Similarly, the second flow path group 27G and the third flow path group 28G are collections of a plurality of in-wall flow paths 27 and 28, respectively, and surround the transition part 23. The first flow path group 26G is located in the downstream side of the flow direction of the combustion gas g in the transition part 23, that is, in the region close to the gas turbine 30. The second flow path group 27G is located in the central region of the flow direction of the combustion gas g in the transition part 23, and is located on the side close to the combustor liner 21 relative to the first flow path group 26G. The third flow path group 28G is the flow path group located on the most upstream side in the flow direction of the combustion gas g, and is located on the side close to the combustor liner 21 relative to the second flow path group 27G. The in-wall flow paths of the first flow path group 26G, the second flow path group 27G, and the third flow path group 28G (in-wall flow paths 26 and 27, and in-wall flow paths 27 and 28) are not connected to each other and are independent of each other.

[0046] The in-wall flow paths 26-28 extend from the side close to the gas turbine 30 to the side close to the combustor liner 21, i.e., along the flow direction of the combustion gas g, inside the plate 25 constituting the transition part 23 (inside the plate thickness). In the first flow path group 26G, the in-wall flow paths 26 adjacent to each other in the circumferential direction of the transition part 23 have the same length. Similarly, in the second flow path group 27G and the third flow path group 28G, the in-wall flow paths 27 and 28 adjacent to each other in the circumferential direction of the transition part 23 have the same length.

[0047] Here, if Figure 5 As shown, the plate 25 constituting the transition part 23 is formed by bonding an outer plate 25a facing the compressed air main flow path 101a and an inner plate 25b facing the combustion gas flow path 23a. The wall flow paths 26-28 are formed as flow paths passing through the interior of the plate 25 by forming slits on the inner surface of the outer plate 25a and bonding the inner plate 25b to the inner surface of the outer plate 25a to block the slits. A structure in which slits are provided on the inner plate 25b can also be adopted. In the present embodiment, the wall flow paths 26 adjacent to each other in the circumferential direction of the transition part 23 are not connected to each other, but if it is necessary, for example, to suppress flow deviation, the adjacent wall flow paths 26 can also be configured to be connected to each other at one or more locations. The same is true for the wall flow paths 27 and 28.

[0048] In each of the in-wall flow paths 26 of the first flow path group 26G, there are one inlet 26a and one outlet 26b for the compressed air a ( Figure 3 and Figure 4 ). The inlet 26a is provided on the outer plate 25a of the plate 25 and faces the compressed air main flow path 101a, penetrates the outer plate 25a in the plate thickness direction and connects the compressed air main flow path 101a with the wall inner flow path 26. The outlet 26b is provided on the inner plate 25b of the plate 25 and faces the combustion gas flow path 23a, penetrates the inner plate 25b in the plate thickness direction and connects the combustion gas flow path 23a with the wall inner flow path 26. During the operation of the gas turbine engine 100, due to the differential pressure generated between the inlet 26a and the outlet 26b, a part of the compressed air a flows from the compressed air main flow path 101a into each wall inner flow path 26 as cooling air and is ejected from the combustion gas flow path 23a. In this way, a part of the compressed air a bypasses the burner 22 ( Figure 1 ) flows in the wall flow path 26, thereby cooling the transition part 23.

[0049] It should be noted that the inlet 26a is connected to the end of one side in the flow direction of the combustion gas g in the wall flow passage 26, and the outlet 26b is connected to the end of the other side in the flow direction of the combustion gas g in the wall flow passage 26. Specifically, in each wall flow passage 26, the inlet 26a is provided at the end on the side close to the gas turbine 30, and the outlet 26b is provided at the end on the side close to the combustor liner 21, and in each wall flow passage 26, the compressed air a flows in the direction opposite to the flow direction of the combustion gas g.

[0050] Each of the in-wall flow paths 27 of the second flow path group 27G has the same structure as the in-wall flow paths 26, and has one inlet 27a and one outlet 27b ( Figure 3 and Figure 4 Each of the in-wall flow paths 28 of the third flow path group 28G similarly includes one inlet 28a and one outlet 28b ( Figure 3 In the present embodiment, the inlet and outlet arrangements of the in-wall flow passages 27 and 28 are the same as those of the in-wall flow passage 26, and the compressed air a flows in the in-wall flow passages 27 and 28 in the opposite direction to the combustion gas g.

[0051] like Figure 3-Figure 10 As shown, the area where the first flow path group 26G is provided overlaps the area where the second flow path group 27G is provided partially by a predetermined overlap amount L1 in the flow direction of the combustion gas g (the direction from the combustor liner 21 toward the gas turbine 30). Specifically, one end of the in-wall flow path 26 of the first flow path group 26G enters between the adjacent in-wall flow paths 27 in the second flow path group 27G, forming a band-shaped overlap portion OL1 where the first flow path group 26G and the second flow path group 27G overlap. The overlap portion OL1 exists around the transition part 23 in the circumferential direction.

[0052] Similarly, the area where the second flow path group 27G is provided and the area where the third flow path group 28G is provided also partially overlap by a predetermined overlap amount L2 in the flow direction of the combustion gas g. Specifically, one end of the in-wall flow path 27 of the second flow path group 27G enters between the adjacent in-wall flow paths 28 in the third flow path group 28G, forming a band-shaped overlap portion OL2 where the second flow path group 27G and the third flow path group 28G overlap. This overlap portion OL2 also exists around the transition part 23 in the circumferential direction.

[0053] It should be noted that the arrangement of the in-wall flow paths 26-28 is dense. In this embodiment, a structure is exemplified in which the interval D between two in-wall flow paths 26 and 27 adjacent to each other in the circumferential direction of the transition part 23 in the overlapping portion OL1 is set to be equal to or smaller than the diameter W of the circular cross section of each in-wall flow path 26 and 27 ( Figure 4 and Figure 5 ). Similarly, in the overlapping portion OL2, the interval D between two adjacent in-wall flow paths 27 and 28 in the circumferential direction of the transition part 23 is also set to be the same as or smaller than the diameter W of the circular cross section of each in-wall flow path 27 and 28.

[0054] Compared with the portion where the shape change of the transition part 23 is relatively small, the aforementioned overlap amounts L1 and L2 are set larger at the portion where the shape change is relatively large. The shape change of the transition part 23 mentioned here refers to, for example, the curvature of the plate 25 forming the transition part 23, the rate of change of the cross-sectional area of ​​the transition part 23, or the rate of change of the width of the transition part 23. The rate of change of the cross-sectional area of ​​the transition part 23 is the ratio of the change in the area of ​​the cross section of the transition part 23 orthogonal to the center line of the combustion gas flow path 23a corresponding to the change in position along the center line of the combustion gas flow path 23a. The rate of change of the width of the transition part 23 is the ratio of the change in the size of the transition part 23 used in the rotation direction or radial direction of the gas turbine 30 corresponding to the change in position along the center line of the combustion gas flow path 23a. For example, the overlap amount L2 is locally different depending on the circumferential position of the transition part 23. In the present embodiment, the overlap amount L2 is wider on the side and ventral side relative to the dorsal side of the transition part 23 ( Figure 8-Figure 10 The degree of difference in the overlap amount L2 based on the circumferential position corresponds to the difference in the shape change of the transition part 23 at each position, for example. Figure 8-Figure 10 The overlap amount L1 can also be changed in value according to the circumferential position, but in the present embodiment, it is substantially constant regardless of the circumferential position of the transition part 23 .

[0055] In addition, in this embodiment, when compared at the same circumferential position, the overlap amount L2 between the second flow path group 27G and the third flow path group 28G is partially different from the overlap amount L1 between the first flow path group 26G and the second flow path group 27G. Specifically, at the side and ventral side of the transition part 23, the overlap amount L2 is wider than the overlap amount L1 ( Fig. 9 , Fig.10 The degree of difference between the overlap amounts L1 and L2 corresponds to the difference in shape change of the transition part 23 at each position, for example. Fig. 9 , Fig.10 The overlap amounts L1 and L2 can also be different on the back side of the transition part 23, but in this embodiment, the overlap amounts L1 and L2 are equal on the back side.

[0056] -Dilution hole-

[0057] The plurality of dilution holes 29 are small holes that penetrate the plate 25 forming the transition part 23 and connect the compressed air main flow path 101a with the combustion gas flow path 23a. The opening diameter is equal to or smaller than the outlets 26b to 28b of the in-wall flow paths 26 to 28. These dilution holes 29 are located in each space between the in-wall flow paths 27 adjacent to each other in the circumferential direction of the transition part 23 of the second flow path group 27G, and are located closer to the inlet 27a of the in-wall flow paths 27 of the second flow path group 27G than the outlet 27b of the in-wall flow paths 27 of the second flow path group 27G. In this way, the dilution holes 29 of the same number as the in-wall flow paths 26 or 27 are alternately arranged with the in-wall flow paths 27 along the overlap portion OL1, forming an annular row around the transition part 23.

[0058] In this embodiment, when the diameter (aperture) of the dilution hole 29 is set to d1, the distance d between the outlet 26b of the in-wall flow path of the first flow path group 26G and the nearest dilution hole 29 is set to a range of 3 to 10 times the diameter d1 of the dilution hole. Considering that if the distance d between the dilution hole 29 and the flow path outlet 26b is too close, it may affect the strength (stress) of the transition part, and if the distance d is too far, it may reduce the cooling effect of the dilution hole, it is preferably set within the above range. In addition, the distance d between the outlet 26b of the in-wall flow path 26 and the nearest dilution hole 29 is the same as or smaller than the diameter W of the circular cross section of the in-wall flow path 26-28 ( Figure 4 The distance d between the outlet 26b and the dilution hole 29 is at least smaller than the maximum value of the overlap amount L1 between the first flow path group 26G and the second flow path group 27G. As an example, the distance d is about 10 mm.

[0059] In addition, the portion where the dilution hole 29 of the transition part 23 is located is a position where the shape change of the transition part 23 is relatively large (for example, larger than the average value of the shape change of each part of the transition part 23). As described above, the shape change refers to, for example, the curvature of the plate 25 forming the transition part 23, the change rate of the cross-sectional area of ​​the transition part 23, or the change rate of the width of the transition part 23. In the transition part 23 whose dimensions in the radial direction (or rotation direction) of the gas turbine 30 change as it approaches the gas turbine 30, the portion where such a dimensional change is extremely large or its vicinity is listed as an example of a preferred position of the dilution hole 29.

[0060] -action-

[0061] During the operation of the gas turbine engine 100, air is taken in and compressed by the compressor 10, and discharged from the compressor 10 to the compressed air main flow path 101a via the diffuser 11 as high-pressure compressed air a. The compressed air a discharged to the compressed air main flow path 101a is supplied to the burner 22 and mixed with the fuel from the fuel system 22b ( Figure 1 ) is ejected into the combustion chamber 21a and burned. As a result, the high-temperature combustion gas g generated in the combustion chamber 21a is supplied to the gas turbine 30 via the transition part 23, and the gas turbine 30 is driven by the combustion gas g. In addition, the load device 200 is driven by the rotation output of the gas turbine 30.

[0062] During this period, a part of the compressed air a flowing from the compressed air main flow path 101a toward the burner 22 bypasses the burner 22 and flows into the wall flow paths 26-28 from the inlets 26a-28a. The compressed air a flowing into the wall flow paths 26-28 flows through the wall flow paths 26-28 to cool the transition part 23, and is ejected to the combustion gas flow path 23a inside the transition part 23 to merge with the combustion gas g. In addition, another part of the compressed air a in the compressed air main flow path 101a bypasses the burner 22 and is ejected to the inside of the transition part 23 from the dilution holes 29. The compressed air a ejected from the plurality of dilution holes 29, which are small holes, forms a film cooling film along the inner wall surface of the transition part 23 and flows toward the gas turbine 30, thereby protecting the plate 25 of the transition part 23 from the heat of the combustion gas g.

[0063] -Effect-

[0064] (1) In the present embodiment, a plurality of in-wall flow paths 26-28 are provided in the transition part 23, and compressed air a is made to flow as cooling air in the plate material 25 constituting the transition part 23, so that the transition part 23 through which the high-temperature combustion gas g passes can be effectively cooled. At this time, since the compressed air a is heated in the process of flowing through the in-wall flow paths 26-28, if each in-wall flow path is extended from one end to the other end of the transition part 23, since each in-wall flow path is long, the temperature of the compressed air a rises near the outlet of each in-wall flow path, and the cooling effect is reduced.

[0065] Therefore, in the present embodiment, the transition part 23 is divided into a plurality of regions in the flow direction of the combustion gas g, and a mutually independent flow path group is formed in each region, thereby reducing the length of each in-wall flow path. As a result, the temperature of the compressed air a near the outlet of each in-wall flow path 26-28 can be reduced, and the cooling effect of the transition part 23 can be improved.

[0066] In addition, if the amount of compressed air a supplied to the burner 22 is too much under the operating condition of a small amount of fuel supply, the combustion temperature decreases and the combustion stability may be impaired. In contrast, in the present embodiment, a part of the compressed air a is supplied to the combustion gas flow path 23a inside the transition part 23 via a plurality of small-diameter dilution holes 29, bypassing the burner 22, and the combustion reaction is completed. This can improve the combustion stability.

[0067] However, the transition part 23 is placed in a thermally harsh environment because it allows the high-temperature combustion gas g that has undergone a combustion reaction in the combustion chamber 21a to pass through, and because the shape is deformed from a circular cross section to a rectangular cross section, stress is likely to increase in shape. If the dilution hole 29 is provided in the transition part 23, stress may be concentrated around the dilution hole 29.

[0068] In contrast, in the present embodiment, in each space between the adjacent in-wall flow paths 27 in the circumferential direction of the second flow path group 27G, a dilution hole 29 is arranged at a position closer to the inlet 27a than the outlet 27b of the in-wall flow path 27 of the second flow path group 27G. The plate 25 near the inlet 27a of the in-wall flow path 27 is cooled by the relatively low-temperature compressed air a shortly after it flows into the in-wall flow path 27, so the metal temperature and stress are low. By providing the dilution hole 29 at this position, it is possible to suppress the stress concentration near the dilution hole 29, and it is possible to suppress the risk of strength associated with the provision of the dilution hole 29. In addition, the compressed air a flowing through the dilution hole 29 can also contribute to the cooling of the transition part 23.

[0069] (2) If the number of dilution holes 29 is reduced and the opening area is increased accordingly, the dilution holes 29 will interfere with the inner wall flow path 27. However, in the present embodiment, the dilution holes 29 are divided into the same number as the number of inner wall flow paths 27, and the opening area of ​​each dilution hole 29 is suppressed to be small. As a result, the interference between the dilution holes 29 and the inner wall flow paths 27 can be avoided, and the inner wall flow paths 27 do not hinder the expected cooling effect. In addition, since the annular row is formed by the plurality of dilution holes 29 with small diameters, a film cooling film (cooling air layer) covering the inner wall of the transition part 23 can be formed. The compressed air a passing through the dilution holes 29 for the purpose of bypassing the burner 22 and improving the combustion stability is also used for film cooling, which can also help protect the transition part 23 from the heat of the combustion gas g.

[0070] (3) From the viewpoint of preventing the compressed air a that bypasses the burner 22 and merges with the combustion gas g from affecting the combustion reaction of the flame, it is advantageous to position the dilution hole 29 close to the gas turbine 30. However, if the distance between the gas turbine 30 and the dilution hole 29 is too short, the compressed air a having a large temperature difference with the combustion gas g will not be sufficiently mixed with the combustion gas g, and the combustion gas g will flow into the gas turbine 30 in a state of non-uniform temperature distribution, which may increase the stress of the gas turbine 30.

[0071] On the other hand, in the present embodiment, the compressed air a ejected from the dilution holes 29 provided in the intervals of the in-wall flow path 27 is ensured to have a mixing distance with the combustion gas g by the length of the first flow path group 26G before being supplied to the gas turbine 30. Therefore, the compressed air a ejected from the dilution holes 29 to the combustion gas flow path 23a can be sufficiently mixed with the combustion gas g, and the temperature distribution of the combustion gas g can be made uniform, thereby suppressing an increase in stress of the gas turbine 30.

[0072] (4) Since there is a temperature difference between the compressed air a ejected from the outlet 26b of the wall-inner flow path 26 of the first flow path group 26G and the compressed air a flowing into the inlet 27a of the wall-inner flow path 27 of the second flow path group 27G, if the outlet 26b and the inlet 27a are too close to each other, the stress in the vicinity thereof may increase. Therefore, by partially overlapping the setting area of ​​the first flow path group 26G and the setting area of ​​the second flow path group 27G, the interval between the outlet 26b and the inlet 27a is ensured, thereby suppressing the increase of the stress in the vicinity. The same applies to the overlapping structure of the second flow path group 27G and the third flow path group 28G. In particular, by setting the overlap amounts L1 and L2 to be larger at the portion where the shape change of the transition part 23 is relatively large, a further effect can be obtained.

[0073] - Modifications -

[0074] The structure in which the annular row of dilution holes 29 is provided along the overlapping portion OL1 is described as an example, but a structure in which the annular row of dilution holes 29 is provided along the overlapping portion OL2 may be used instead of or in addition to this structure.

[0075] Although the configuration in which a difference is given to the overlap amount L2 according to the size of the shape change of the transition part 23 is exemplified, such adjustment of the overlap amount is not necessarily necessary as long as the above-mentioned essential effect (1) can be obtained.

[0076] In addition, in the present embodiment, the configuration in which three flow path groups, namely the first flow path group 26G to the third flow path group 28G, are provided in the transition part 23 is exemplified, but the region of the transition part 23 may be divided into two so that the flow path groups are two. The region of the transition part 23 may be divided into four or more so that the flow path groups are four or more.

[0077] The inlet or outlet of each of the wall passages 26-28 may be shared by adjacent wall passages, that is, the inlet or outlet may be enlarged or formed into a long hole that is long in the circumferential direction, and one inlet or outlet may communicate with a plurality of wall passages.

[0078] Although the example in which the inner wall flow paths 26 to 28 are formed by bonding the outer plate 25a with slits to the inner plate 25b of the plate 25 has been described, the method of forming the inner wall flow paths 26 to 28 can be changed as appropriate.

Claims

1. A transition part provided in a combustor that causes fuel to burn together with compressed air compressed by a compressor of a gas turbine engine inside a combustor liner to supply combustion gas to a gas turbine, the transition part connecting the combustor liner to the gas turbine and being formed into a cylindrical shape by a plate material, separating an outer compressed air main flow path for supplying the compressed air from the compressor to the combustor from an inner combustion gas flow path for supplying the combustion gas from the combustor liner to the gas turbine, The transition part is characterized in that The transition part has: a first flow path group formed by arranging a plurality of in-wall flow paths extending from a side close to the gas turbine to a side close to the combustor liner inside the plate in a circumferential direction of the transition part; a second flow path group located on a side close to the combustor liner relative to the first flow path group and formed by arranging a plurality of in-wall flow paths extending from a side close to the gas turbine to a side close to the combustor liner inside the plate in a circumferential direction of the transition part; and a plurality of dilution holes that penetrate the plate and connect the compressed air main flow path with the combustion gas flow path, Each of the in-wall flow paths of the first flow path group and the second flow path group has an inlet facing the main compressed air flow path at an end portion on a side close to the gas turbine, and has an outlet facing the combustion gas flow path at an end portion on a side close to the combustor liner. In each space between adjacent intra-wall flow paths of the second flow path group, the dilution hole is located closer to the inlet of the intra-wall flow paths of the second flow path group than the outlet of the intra-wall flow paths of the second flow path group, and closer to the side of the combustor liner than the outlet of the intra-wall flow paths of the first flow path group.

2. The transition part according to claim 1, characterized in that The transition component includes an overlapping portion where a region where the first flow path group is provided and a region where the second flow path group is provided partially overlap in the flow direction of the combustion gas.

3. The transition part according to claim 1, characterized in that The distance between the outlet of the in-wall flow channel of the first flow channel group and the dilution hole is in a range of 3 to 10 times the hole diameter of the dilution hole.

4. The transition part according to claim 1, characterized in that A distance between two adjacent in-wall flow paths in the circumferential direction of the transition part is equal to or smaller than a diameter of each in-wall flow path of the first flow path group and the second flow path group.

5. A burner, wherein: The combustor includes the transition piece according to claim 1.

6. A gas turbine engine, characterized in that: The gas turbine engine comprises: a compressor that compresses air to generate compressed air; The combustor according to claim 5, which generates combustion gas by combusting fuel together with compressed air discharged from the compressor; and A gas turbine is driven by the combustion gas supplied from the combustor.

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