Intake casing, axial flow compressor comprising said intake casing, and gas turbine comprising said axial flow compressor

Abstract

This intake casing comprises: an intake chamber casing in which an introduction annular flow passage and an introduction flow passage are formed, said introduction flow passage being capable of introducing air into the introduction annular flow passage from the outer circumference side of the introduction annular flow passage; a bell mouth in which an annular intake flow passage is formed, said intake flow passage being capable of introducing air into a compressor casing from the introduction annular flow passage; a partition plate that is positioned in the introduction annular flow passage; and a plurality of struts that are positioned in the intake flow passage side by side in the circumferential direction with respect to an axis. The partition plate partitions the interior of the introduction annular flow passage into one side and another side in the circumferential direction. The plurality of struts extend radially outward from the inner circumference edge of the intake flow passage to the outer circumference edge of the intake flow passage. Among the plurality of struts, the location of one strut in the circumferential direction is within ±2.5° in the circumferential direction with respect to the location of the partition plate in the circumferential direction.

Description

An intake casing, an axial flow compressor including this intake casing, and a gas turbine including this axial flow compressor

[0001] The present disclosure relates to an intake casing, an axial flow compressor including this intake casing, and a gas turbine including this axial flow compressor. This application claims priority based on Japanese Patent Application No. 2024-186192 filed in Japan on October 22, 2024, and incorporates this content herein by reference.

[0002] The gas turbine has an axial flow compressor capable of compressing air to generate compressed air, a combustor capable of burning fuel in the compressed air to generate combustion gas, a turbine drivable by the combustion gas, an intake casing, and an intermediate casing.

[0003] The axial flow compressor has a compressor rotor rotatable about an axis, a compressor casing covering the compressor rotor, and an intake casing for guiding air into the compressor casing. The turbine is disposed on the downstream side of the axis with respect to the compressor. This turbine has a turbine rotor rotatable about an axis and a turbine casing covering the turbine rotor. The turbine rotor is connected to the compressor rotor.[[ID=A]] [[ID=B]]

[0004] The intake casing is connected to the upstream end of the axis of the compressor casing so as to guide air into the compressor casing. The intermediate casing is disposed between the compressor casing and the turbine casing in the axial direction. The combustor is attached to the intermediate casing so that the compressed air discharged from the axial flow compressor into the intermediate casing can flow in.

[0005] The following Patent Document 1 describes an intake casing of an axial flow compressor. This intake casing has an intake chamber casing and a partition plate. In the intake chamber casing, an annular introduction annular flow path around the axis and an introduction flow path capable of introducing air from the outer peripheral side of the introduction annular flow path into the introduction annular flow path are formed. The partition plate is disposed in the introduction annular flow path and in a region on the opposite side of the introduction flow path with respect to the axis. This partition plate extends radially inward from the outer peripheral edge of the annular introduction annular flow path toward the axis and partitions the inside of the introduction annular flow path into one side and the other side in the circumferential direction.

[0006] Japanese Patent Publication No. 2012-207619

[0007] The intake casing is required to minimize intake resistance and efficiently guide air into the main casing of the axial compressor.

[0008] Therefore, the present disclosure aims to provide an intake casing capable of suppressing intake resistance, an axial flow compressor equipped with this intake casing, and a gas turbine equipped with this axial flow compressor.

[0009] An intake casing as one embodiment for achieving the above objective is an intake casing capable of introducing air into a compressor casing that covers a compressor rotor rotatable around an axis. This intake casing comprises an intake chamber casing having an annular introduction passage around the axis and an introduction passage from the outer circumference side of the introduction passage into the introduction passage; a bell mouth that is annular around the axis and has an intake passage formed therein that allows air to be introduced from the introduction passage into the compressor casing; a partition plate located within the introduction passage in a region opposite to the introduction passage with respect to the axis; and a plurality of struts located within the intake passage, arranged in a circumferential direction with respect to the axis. The bell mouth is located on the downstream side of the axis in the axial direction in which the axis extends, and is connected to the intake chamber casing so that the intake passage and the introduction passage can communicate with each other. The partition plate extends radially inward from the outer peripheral edge of the annular intake passage with respect to the axis, dividing the annular intake passage into one side and the other side in the circumferential direction. Each of the plurality of struts extends radially outward from the inner peripheral edge of the annular intake passage with respect to the outer peripheral edge of the intake passage. The circumferential position of one of the plurality of struts is within ±2.5° in the circumferential direction with respect to the circumferential position of the partition plate.

[0010] Another embodiment of an intake casing for achieving the above objective is an intake casing capable of introducing air into a compressor casing that covers a compressor rotor rotatable around an axis. This intake casing comprises an intake chamber casing having an annular introduction passage around the axis and an introduction passage from the outer circumference side of the introduction passage into the introduction passage; a bell mouth that is annular around the axis and has an intake passage formed therein that allows air to be introduced from the introduction passage into the compressor casing; a partition plate located within the introduction passage in a region opposite to the introduction passage with respect to the axis; and a plurality of struts located within the intake passage, arranged in a circumferential direction with respect to the axis. The bell mouth is located on the downstream side of the axial direction in which the axis extends, and is connected to the intake chamber casing so that the intake passage and the introduction passage can communicate with each other. The partition plate extends radially inward from the outer peripheral edge of the annular intake passage with respect to the axis, dividing the annular intake passage into one side and the other side in the circumferential direction. Each of the plurality of struts extends radially outward from the inner peripheral edge of the annular intake passage with respect to the axis. At least a portion of the circumferential region of one of the plurality of struts overlaps in the circumferential direction with the circumferential region of the partition plate.

[0011] In the aforementioned embodiment and the other embodiment, the air that flows from the introduction channel into the introduction annular channel, and reaches near the partition plate, flows radially inward and axially downstream, that is, in the process of flowing into the intake channel, the struts in the intake channel hardly obstruct this airflow. Therefore, in the process of the air that reaches near the partition plate flowing into the intake channel, almost no vortex flow occurs. In other words, in the intake casing of the aforementioned embodiment and the other embodiment, air flows smoothly from inside the intake chamber casing into the bell mouth. Thus, in the intake casing of the aforementioned embodiment and the other embodiment, intake resistance can be suppressed and air can be efficiently guided into the compressor casing of the compressor.

[0012] An axial flow compressor as one embodiment for achieving the above objective comprises an intake casing in the above embodiment or the other embodiment, a compressor rotor, and the compressor casing.

[0013] A gas turbine as one embodiment for achieving the above objective comprises an axial compressor as described above, a combustor capable of generating combustion gas by burning fuel in air compressed by the axial compressor, and a turbine that can be driven by the combustion gas.

[0014] In one aspect of this disclosure, intake resistance can be reduced.

[0015] This is a schematic cross-sectional view of a gas turbine in one embodiment of the present disclosure. This is a cross-sectional view of an intake casing in one embodiment of the present disclosure. This is a cross-sectional view taken along line III-III in Figure 2. This is a cross-sectional view of an intake casing in a comparative example. This is a cross-sectional view taken along line V-V in Figure 4.

[0016] Hereinafter, embodiments of the intake casing, the axial compressor equipped with the intake casing, and the gas turbine equipped with the axial compressor relating to this disclosure will be described with reference to the drawings.

[0017] "Embodiment of an Axial Flow Compressor and a Gas Turbine Equipped with the Axial Flow Compressor" Hereinafter, an embodiment of the gas turbine in this embodiment will be described with reference to Figure 1.

[0018] The gas turbine in this embodiment includes an axial flow compressor (hereinafter simply referred to as a compressor) 30 capable of compressing air A to generate compressed air Acom, a plurality of combustors 10 that burn fuel F in the compressed air Acom to generate combustion gas G, a turbine 20 driven by the high-temperature, high-pressure combustion gas G, an intermediate casing 5, a front bearing 2f, and a rear bearing 2b.

[0019] The compressor 30 includes a compressor rotor 31 rotatable about an axis Ar, a compressor casing 32 covering the compressor rotor 31, a plurality of compressor stator blade rows 33, an intake volume regulator 34, and an intake casing 40. The turbine 20 includes a turbine rotor 21 rotatable about an axis Ar, a turbine casing 22 covering the turbine rotor 21, a plurality of turbine stator blade rows 23, and an exhaust casing 25.

[0020] In the following, the direction in which the axis Ar extends is referred to as the axial direction Da, one side of the axial direction Da is referred to as the upstream axis Dau, and the other side of the axial direction Da is referred to as the downstream axis Dad. The circumferential direction centered on the axis Ar is simply referred to as the circumferential direction Dc. Furthermore, the direction perpendicular to the axis Ar is referred to as the radial direction Dr, the side of the radial direction Dr that approaches the axis Ar is referred to as the radially inner Dri, and the opposite side is referred to as the radially outer Dr.

[0021] The compressor 30 is positioned axially upstream Dau of the turbine 20. The compressor rotor 31 has a compressor rotor shaft 31s extending axially Da with respect to the axis Ar, and a plurality of compressor rotor blade rows 31b attached to this compressor rotor shaft 31s. The plurality of compressor rotor blade rows 31b are arranged axially Da. Each compressor rotor blade row 31b is composed of a plurality of rotor blades arranged circumferentially Dc. One of the plurality of compressor stator blade rows 33 is positioned axially downstream Dad of each of the plurality of compressor rotor blade rows 31b. Each compressor stator blade row 33 is mounted inside the compressor casing 32. Each compressor stator blade row 33 is composed of a plurality of stator blades arranged circumferentially Dc. The intake volume regulator 34 includes a plurality of inlet guide vanes 34v and a drive unit 34d that can change the orientation of each inlet guide vane 34v. The plurality of inlet guide vanes 34v are positioned upstream Dau of the axis from the plurality of compressor blade rows 31b. The plurality of inlet guide vanes 34v are arranged in the circumferential direction Dc.

[0022] The intake casing 40 is positioned on the axial upstream side Dau of the compressor casing 32 and is connected to the end of this axial upstream side Dau of the compressor casing 32. The intake casing 40 is configured to allow external air A to be drawn into the compressor casing 32.

[0023] The turbine rotor 21 has a turbine rotor shaft 21s extending in the axial direction Da with respect to the axis Ar, and a plurality of turbine rotor blade rows 21b attached to the turbine rotor shaft 21s. The plurality of turbine rotor blade rows 21b are arranged in the axial direction Da. Each turbine rotor blade row 21b is composed of a plurality of rotor blades arranged in the circumferential direction Dc. One of the plurality of turbine stator blade rows 23 is positioned on the upstream side Du of each of the plurality of turbine rotor blade rows 21b. Each turbine stator blade row 23 is mounted inside the turbine casing 22. Each turbine stator blade row 23 is composed of a plurality of stator blades arranged in the circumferential direction Dc.

[0024] The exhaust casing 25 is connected to the upstream end of the turbine casing 22 on the axis of Dau. The exhaust casing 25 has an inner exhaust casing 25i, an outer exhaust casing 25o, and a plurality of exhaust struts 26. The inner exhaust casing 25i is cylindrical with the axis Ar as its center and covers the portion of the turbine rotor shaft 21s downstream of the plurality of turbine blade rows 21b on the axis of Dau. The outer exhaust casing 25o is cylindrical with the axis Ar as its center and is spaced radially outward from the inner exhaust casing 25i on the axis of Dau. The upstream end of the outer exhaust casing 25o on the axis of Dau is connected to the downstream end of the turbine casing 22 on the axis of Dau. The space between the inner exhaust casing 25i and the outer exhaust casing 25o in the radial direction Dr forms an exhaust passage through which the exhaust gas, which is the combustion gas G exhausted from the turbine casing 22, flows. Multiple exhaust struts 26 are arranged circumferentially in the direction Dc between the inner exhaust casing 25i and the outer exhaust casing 25o. The radially inner end Dri of the exhaust strut 26 is connected to the inner exhaust casing 25i. The radially outer end Doro of the exhaust strut 26 is connected to the outer exhaust casing 25o.

[0025] The intermediate casing 5 is positioned in the axial direction Da between the compressor casing 32 and the turbine casing 22 of the compressor 30. The axial upstream end Dau of the intermediate casing 5 is connected to the axial downstream end Dad of the compressor casing 32. The axial downstream end Dad of the intermediate casing 5 is connected to the axial upstream end Dau of the turbine casing 22. Multiple combustors 10 are mounted on the intermediate casing 5, aligned in the circumferential direction Dc.

[0026] The compressor rotor 31 and the turbine rotor 21 are located on the same axis Ar and are connected to each other to form a gas turbine rotor 1. For example, the rotor of a generator GEN is connected to this gas turbine rotor 1. The upstream portion of the gas turbine rotor 1 along the axis Da is rotatably supported by a front bearing 2f. The downstream portion of the gas turbine rotor 1 along the axis Da is rotatably supported by a rear bearing 2b. The front bearing 2f is located in the axial direction Da where the intake casing 40 is located. The rear bearing 2b is located in the axial direction Da where a plurality of exhaust struts 26 are located. This rear bearing 2b is supported by a plurality of exhaust struts 26 via an exhaust inner casing 25i.

[0027] The compressor 30 draws in air A and compresses it. The compressed air A, or compressed air Acom, flows from the compressor 30 into the intermediate casing 5. This compressed air Acom flows into a plurality of combustors 10 attached to the intermediate casing 5. Fuel F is supplied to the plurality of combustors 10 from the outside. Inside the plurality of combustors 10, the fuel F burns in the compressed air Acom to produce high-temperature, high-pressure combustion gas G. This combustion gas G flows into the turbine casing 22. The turbine rotor 21 rotates due to the combustion gas G that has flowed into the turbine casing 22. The combustion gas G exhausted from the turbine casing 22 is exhausted to the outside as exhaust gas through the exhaust casing 25.

[0028] "Embodiment of the Intake Casing" The intake casing 40 described above will be explained in detail below with reference to Figures 2 to 5.

[0029] As shown in Figures 2 and 3, the intake casing 40 in this embodiment includes an intake chamber casing 41 into which air A from the outside can flow, a bell mouth 51 into which air A from the intake chamber casing 41 can be introduced into the compressor casing 32, a partition plate 47 arranged inside the intake casing 40, and a plurality of intake struts (hereinafter simply referred to as struts) 56 arranged inside the bell mouth 51.

[0030] The intake chamber casing 41 has an annular intake passage 43 around the axis Ar, and an intake passage 42 into which air A can be introduced from the outer circumference of the intake passage 43. This intake passage 42 is located on the outer circumference of the intake passage 43, above the intake passage 43, and extends vertically. Therefore, this intake passage 42 is positioned vertically above the axis Ar. The vertically upper edge of this intake passage 42 forms an intake port 42i into which air A from the outside flows.

[0031] The intake chamber casing 41 includes a front plate 44 that defines the edge of the axial upstream side Dau in the introduction passage 42 and the introduction annular passage 43, a rear plate 45 that defines the edge of the axial downstream side Dad in the introduction passage 42, and a side peripheral plate 46 that defines the edge of the side circumference in the introduction passage 42 and the introduction annular passage 43. The front plate 44 and the rear plate 45 are spaced apart in the axial direction Da. The side peripheral plate 46 connects the side peripheral edge of the front plate 44 and the side peripheral edge of the rear plate 45. The aforementioned intake port 42i is defined by the upper edge of the front plate 44, the upper edge of the rear plate 45, and the upper edge of the side peripheral plate 46. The front plate 44 has a circular opening 44o centered on the axis Ar. The rear plate 45 also has a circular opening 45o centered on the axis Ar. The radius of the circular opening 45o in the rear plate 45 is larger than the radius of the circular opening 44o in the front plate 44.

[0032] The bell mouth 51 has an annular intake passage 52 formed around its axis Ar, which allows air A to be guided from the introduction annular passage 43 into the compressor casing 32. The bell mouth 51 is located on the downstream side Da of the intake chamber casing 41 and is connected to the intake chamber casing 41 so that the intake passage 52 and the introduction annular passage 43 inside the intake chamber casing 41 can communicate with each other.

[0033] The bell mouth 51 has an inner bell mouth 54 that defines the inner peripheral edge 52i of the annular intake passage 52, and an outer bell mouth 55 that defines the outer peripheral edge 52o of the annular intake passage 52. The inner bell mouth 54 is cylindrical with the axis Ar as its center, and covers the portion of the compressor rotor shaft 31s that is upstream of the inlet guide vane 34v on the axis Dau. This inner bell mouth 54 is formed so that it gradually turns radially outward Dr as it approaches the upstream side Dau on the axis. The edge of the inner bell mouth 54 on the upstream side Dau on the axis is connected to the edge of the opening 44o of the front plate 44. The outer bell mouth 55 is cylindrical with the axis Ar as its center, and is positioned radially outward Dr away from the inner bell mouth 54. This outer bell mouth 55 is also formed so that it gradually turns radially outward Dr as it approaches the upstream side Dau on the axis. The edge of the outer bell mouth 55 on the axial upstream side Dau is connected to the edge of the opening 45o of the rear plate 45. Also, the edge of the outer bell mouth 55 on the axial downstream side Dad is connected to the edge of the compressor casing 32 on the axial upstream side Dau. The outer peripheral edge 43o of the introduction annular passage 43 is located radially outward Dr than the outer peripheral edge 52o of the intake passage 52 at the connection point of the bell mouth 51 to the intake chamber casing 41. In other words, the outer peripheral edge 43o of the introduction annular passage 43 is located radially outward Dr than the edge of the outer bell mouth 55 on the axial upstream side Dau.

[0034] Multiple struts 56 are arranged in the intake passage 52, aligned in the circumferential direction Dc with respect to the axis Ar. The radially inner edge Dri of each strut 56 is connected to the inner bell mouth 54. The radially outer edge Dr of each strut 56 is connected to the outer bell mouth 55. That is, each of the multiple bell mouths 51 extends radially outward Dr from the inner peripheral edge 52i of the annular intake passage 52 to the outer peripheral edge 52o of the intake passage 52.

[0035] The aforementioned front bearing 2f is positioned on the inner circumference side of the inner bell mouth 54 and is attached to this inner bell mouth 54. This front bearing 2f is supported by multiple struts 56 via the inner bell mouth 54.

[0036] The partition plate 47 is located within the introduction annular passage 43, in a region opposite to the introduction passage 42 with respect to the axis Ar. In this embodiment, the partition plate 47 is located vertically below the axis Ar. This partition plate 47 extends radially inward Dri from the outer peripheral edge 43o of the annular introduction annular passage 43 to a position within the position of the outer peripheral edge 52o of the intake passage 52, thereby dividing the introduction annular passage 43 into one side and the other side in the circumferential direction Dc. For this reason, the radially inward edge 47i of the partition plate 47, that is, the upper edge of the partition plate 47, is located radially in Dr at the position of the edge Dad on the downstream side of the axis of the outer bell mouth 55, or radially outward Dr from the position of the edge Dad on the downstream side of the axis of the outer bell mouth 55. The axially upstream edge 47u of the partition plate 47 is connected to the front plate 44. The radially outer edge 47o of the partition plate 47, that is, the lower edge of the partition plate 47, is connected to the side peripheral plate 46. The axially downstream edge 47d of the partition plate 47, Dad, is connected to the rear plate 45. The radially inner edge 47i of the partition plate 47, that is, the upper edge of the partition plate 47, is not connected to any member.

[0037] The maximum thickness of the partition plate 47, that is, the maximum thickness of the partition plate 47 in the circumferential direction Dc, is thinner than the maximum thickness of each strut 56, that is, the maximum width of each strut 56 in the circumferential direction Dc. Therefore, the rigidity of the partition plate 47 is lower than the rigidity of each strut 56. A reinforcing beam 48 is provided on the surface of the partition plate 47 facing the circumferential direction Dc. The reinforcing beam 48 extends from a position Da on the downstream side of the axis of the partition plate 47 and radially outward Do, to a position Dau on the upstream side of the axis of the partition plate 47 and radially inward Dri.

[0038] Of the multiple struts 56, the position of one strut 56a in the circumferential direction Dc is within a predetermined angle α in the circumferential direction Dc with respect to the position of the partition plate 47 in the circumferential direction Dc, as shown in Figure 3. This predetermined angle is ±2.5°. Furthermore, at least a portion of the area where this one strut 56a exists in the circumferential direction Dc is an overlapping area 57 that overlaps with the area where the partition plate 47 exists in the circumferential direction Dc.

[0039] Next, the effects of the intake casing 40 in this embodiment will be explained while describing the intake casing 40C in the comparative example shown in Figures 4 and 5.

[0040] The intake casing 40C in the comparative example also comprises an intake chamber casing 41, a bell mouth 51, a partition plate 47, and a plurality of struts 56, similar to the intake casing 40 in this embodiment. However, the relative position of one of the struts 56 in the circumferential direction Dc with respect to the partition plate 47 differs between the intake casing 40 in this embodiment and the intake casing 40C in the comparative example. Furthermore, the position of the radially inner edge 47i of the partition plate 47, that is, the position of the upper edge of the partition plate 47, also differs between the intake casing 40 in this embodiment and the intake casing 40C in the comparative example.

[0041] In the comparative example intake casing 40C, the position of one of the multiple struts 56 in the circumferential direction Dc is outside a predetermined angle α range in the circumferential direction Dc with respect to the position of the partition plate 47 in the circumferential direction Dc. Furthermore, the area of ​​existence of this one strut 56 in the circumferential direction Dc does not overlap at all with the area of ​​existence of the partition plate 47 in the circumferential direction Dc.

[0042] In the comparative example intake casing 40C, as shown in Figure 5, of the air A that flows from the introduction passage 42 into the introduction annular passage 43, the air A that reaches near the partition plate 47 flows radially inward Dri and axially downstream Dad, that is, in the process of flowing into the intake passage 52, and the strut 56 in the intake passage 52 obstructs the flow of this air A. As a result, a vortex flow is generated in the air A as it flows into the intake passage 52 after reaching near the partition plate 47. Therefore, in the comparative example intake casing 40C, this vortex flow increases the intake resistance.

[0043] On the other hand, in the intake casing 40 of this embodiment, as shown in Figure 3, of the air A that flows from the introduction passage 42 to the introduction annular passage 43, the struts 56 in the intake passage 52 hardly obstruct the flow of the air A that reaches near the partition plate 47 as it flows radially inward Dri and axially downstream Dad, that is, as it flows into the intake passage 52. Therefore, as the air A that reaches near the partition plate 47 flows into the intake passage 52, almost no vortex flow occurs in the air A. In other words, in the intake casing 40 of this embodiment, the air A flows smoothly from inside the intake chamber casing 41 into the bell mouth 51. Thus, in the intake casing 40 of this embodiment, intake resistance can be suppressed and air A can be efficiently guided into the compressor casing 32 of the compressor 30.

[0044] In the comparative example, the partition plate 47 extends from the outer peripheral edge 43o of the annular introduction passage 43 to a position radially inward Dri than the position of the outer peripheral edge 52o of the intake passage 52. Therefore, the radially inward Dri edge 47i of the partition plate 47 in the comparative example, that is, the upper edge of the partition plate 47, is located radially inward Dri than the position of the edge Da on the downstream side of the axis of the outer bell mouth 55.

[0045] Therefore, the distance from the radially outer edge 47o of the partition plate 47 connected to the side peripheral plate 46, that is, the lower edge of the partition plate 47, to the radially inner edge 47i of the partition plate 47 not connected to any member, that is, the upper edge of the partition plate 47, is shorter for the partition plate 47 in the present embodiment than for the partition plate 47 in the comparative example. For this reason, the moment applied to the radially inner edge 47i of the partition plate 47, that is, the upper edge of the partition plate 47, with the radially outer edge 47o of the partition plate 47 connected to the side peripheral plate 46, that is, the lower edge of the partition plate 47 as the base point, is smaller for the partition plate 47 in the present embodiment than for the partition plate 47 in the comparative example. For this reason, in the partition plate 47 in the present embodiment, damage to the radially inner edge 47i of the partition plate 47, that is, the upper edge of the partition plate 47, can be suppressed. Furthermore, in the partition plate 47 in the present embodiment, among the connection portions between the front plate 44 and the upstream edge 47u in the axial direction Dau of the partition plate 47, damage to the radially inner portion Dri can be suppressed, and among the connection portions between the rear plate 45 and the downstream edge 47d in the axial direction Dad of the partition plate 47, damage to the radially inner portion Dri can be suppressed.

[0046] "Modification" In the above embodiment, the partition plate 47 is disposed directly below the axis Ar. However, the partition plate 47 does not have to be disposed directly below the axis Ar as long as it is disposed within the region on the side opposite to the introduction flow path 42 with respect to the axis Ar.

[0047] In the above embodiment, the introduction flow path 42 is on the outer peripheral side of the introduction annular flow path 43, located above the introduction annular flow path 43, and extends in the vertical direction. However, the introduction flow path 42 may be on the outer peripheral side of the introduction annular flow path 43, located in the lateral direction of the introduction annular flow path 43, and extend in the lateral direction.

[0048] Further, the present disclosure is not limited to the embodiments described above. Various additions, changes, replacements, partial deletions, etc. are possible without departing from the conceptual ideas and spirits of the present invention derived from the content defined in the claims and their equivalents.

[0049] "Note" The intake casing 40 in each of the above embodiments can be understood, for example, as follows: (1) The intake casing 40 in the first embodiment is an intake casing capable of introducing air A into a compressor casing 32 that covers a compressor rotor 31 that is rotatable around an axis Ar. This intake casing 40 comprises an intake chamber casing 41 having an annular introduction passage 43 around the axis Ar and an introduction passage 42 that allows air A to be introduced into the introduction annular passage 43 from the outer circumference side of the introduction annular passage 43; a bell mouth 51 that is annular around the axis Ar and has an intake passage 52 that allows air A to be introduced from the introduction annular passage 43 into the compressor casing 32; a partition plate 47 located within the introduction annular passage 43 in a region opposite to the introduction passage 42 with respect to the axis Ar; and a plurality of struts 56 located within the intake passage 52, arranged in the circumferential direction Dc with respect to the axis Ar. The bell mouth 51 is positioned on the downstream side Da of the axial direction Da along which the axis Ar extends, relative to the intake chamber casing 41, and is connected to the intake chamber casing 41 so that the intake passage 52 and the introduction annular passage 43 can communicate with each other. The partition plate 47 extends radially inward Dri from the outer peripheral edge 43o of the annular introduction annular passage 43 with respect to the axis Ar, and divides the inside of the introduction annular passage 43 into one side and the other side in the circumferential direction Dc. The plurality of struts 56 each extend radially outward Dro from the inner peripheral edge 52i of the annular intake passage 52 to the outer peripheral edge 52o of the intake passage 52 with respect to the axis Ar. Of the plurality of struts 56, the position of one strut 56a in the circumferential direction Dc is within ±2.5° of the circumferential direction Dc relative to the position of the partition plate 47 in the circumferential direction Dc.

[0050] In this embodiment, of the air A that flows from the introduction passage 42 to the introduction annular passage 43, the struts 56a in the intake passage 52 hardly obstruct the flow of the air A that reaches near the partition plate 47 as it flows radially inward Dri and axially downstream Dad, that is, as it flows into the intake passage 52. Therefore, as the air A that reaches near the partition plate 47 flows into the intake passage 52, almost no vortex flow occurs in the air A. In other words, in the intake casing 40 in this embodiment, the air A flows smoothly from inside the intake chamber casing 41 into the bell mouth 51. Thus, in the intake casing 40 in this embodiment, intake resistance can be suppressed and the air A can be efficiently guided into the compressor casing 32 of the compressor 30.

[0051] (2) The intake casing 40 in the second embodiment is an intake casing capable of introducing air A into a compressor casing 32 that covers a compressor rotor 31 that is rotatable around an axis Ar. The intake casing 40 comprises an intake chamber casing 41 having an annular introduction passage 43 around the axis Ar and an introduction passage 42 that allows air A to be introduced into the introduction annular passage 43 from the outer circumference side of the introduction annular passage 43; a bell mouth 51 that is annular around the axis Ar and has an intake passage 52 that allows air A to be introduced from the introduction annular passage 43 into the compressor casing 32; a partition plate 47 located within the introduction annular passage 43 in a region opposite to the introduction passage 42 with respect to the axis Ar; and a plurality of struts 56 located within the intake passage 52, arranged in the circumferential direction Dc with respect to the axis Ar. The bell mouth 51 is positioned on the downstream side Da of the axial direction Da along which the axis Ar extends, relative to the intake chamber casing 41, and is connected to the intake chamber casing 41 so that the intake passage 52 and the introduction annular passage 43 can communicate with each other. The partition plate 47 extends radially inward Dri from the outer peripheral edge 43o of the annular introduction annular passage 43 with respect to the axis Ar, and divides the inside of the introduction annular passage 43 into one side and the other side in the circumferential direction Dc. The plurality of struts 56 each extend radially outward Dro from the inner peripheral edge 52i of the annular intake passage 52 to the outer peripheral edge 52o of the intake passage 52 with respect to the axis Ar. Of the plurality of struts 56, at least a portion of the area of ​​existence of one strut 56a in the circumferential direction Dc overlaps with the area of ​​existence of the partition plate 47 in the circumferential direction Dc.

[0052] In this embodiment, of the air A that flows from the introduction passage 42 into the introduction annular passage 43, the struts 56 in the intake passage 52 hardly obstruct the flow of the air A that reaches near the partition plate 47 as it flows radially inward Dri and axially downstream Dad, that is, as it flows into the intake passage 52. Therefore, as the air A that reaches near the partition plate 47 flows into the intake passage 52, almost no vortex flow occurs in the air A. In other words, in the intake casing 40 in this embodiment, the air A flows smoothly from inside the intake chamber casing 41 into the bell mouth 51. Thus, in the intake casing 40 in this embodiment, intake resistance can be suppressed and the air A can be efficiently guided into the compressor casing 32 of the compressor 30.

[0053] (3) In the third embodiment, the intake casing 40 is such that, in the intake casing 40 of the first or second embodiment, the outer peripheral edge 43o of the introduction annular passage 43 is located radially outward Dr than the outer peripheral edge 52o of the intake passage 52 at the connection position of the bell mouth 51 with the intake chamber casing 41. The partition plate 47 extends radially outward Dr from the outer peripheral edge 43o of the introduction annular passage 43 to a position within the position of the outer peripheral edge 52o of the intake passage 52 at the connection position.

[0054] Here, a comparative example is given in which the partition plate 47 extends radially inward Dri from the outer peripheral edge 43o of the introduction annular passage 43 to the position of the outer peripheral edge 52o of the intake passage 52. In this embodiment, compared to the comparative example, the moment acting on the radially inward Dri edge 47i of the partition plate 47 is smaller, with the radially outward Dri edge 47o of the partition plate 47 as the starting point. Therefore, in this embodiment, damage around the radially inward Dri edge 47i of the partition plate 47 can be suppressed.

[0055] (4) In the intake casing 40 in the fourth embodiment, the rigidity of the partition plate 47 is lower than the rigidity of each of the plurality of struts 56 in the intake casing 40 in any one of the first to third embodiments.

[0056] The axial flow compressor 30 in each of the above embodiments can be understood, for example, as follows: (5) The axial flow compressor 30 in the fifth embodiment comprises the intake casing 40 in any one of the first to fourth embodiments, the compressor rotor 31, and the compressor casing 32.

[0057] The gas turbines in each of the above embodiments can be understood, for example, as follows: (6) The gas turbine in the sixth embodiment comprises the axial compressor 30 in the fifth embodiment, a combustor 10 capable of generating combustion gas G by burning fuel F in air compressed by the axial compressor 30, and a turbine 20 that can be driven by the combustion gas G.

[0058] According to one aspect of this disclosure, intake resistance can be reduced.

[0059] 1: Gas turbine rotor 2f: Front bearing 2b: Rear bearing 5: Intermediate casing 10: Combustor 20: Turbine 21: Turbine rotor 21s: Turbine rotor shaft 21b: Turbine blade row 22: Turbine casing 23: Turbine stator blade row 25: Exhaust casing 25i: Exhaust inner casing 25o: Exhaust outer casing 26: Exhaust strut 30: Axial compressor (or simply compressor) 31: Compressor rotor 31s: Compressor rotor shaft 31b: Compressor blade row 32: Compressor casing 33: Compressor stator blade row 34: Intake volume regulator 34v: Inlet guide vane 34d: Drive unit 40, 40C: Intake casing 41: Intake chamber casing 42: Intake passage 42i: Intake port 43: Intake annular passage 43o: Outer edge (of the intake annular passage) 44: Front plate 44o: Opening 45: Rear plate 45o: Opening 46: Side perimeter plate 47: Partition plate 47i: Edge (radially inward of partition plate) 47o: Edge (radially outward of partition plate) 47u: Edge (upstream of partition plate axis) 47d: Edge (downstream of partition plate axis) 48: Reinforcement beam 51: Bell mouth 52: Intake passage 52i: Inner perimeter of intake passage 52o: Outer perimeter of intake passage 54: Inner bell mouth 55: Outer bell mouth 56, 56a: Intake strut (or simply strut) 57: Overlap region A: Air Acom: Compressed air F: Fuel G: Combustion gas Ar: Axis Da: Axial direction Dau: Upstream of axis Dad: Downstream of axis Dc: Circumferential direction Dr: radial direction; Dri: radially inward; Dro: radially outward

Claims

1. An intake casing capable of introducing air into a compressor casing covering a compressor rotor rotatable around an axis, comprising: an intake chamber casing having an annular intake passage around the axis and an intake passage from the outer circumference side of the intake annular passage into which air can be introduced; a bell mouth that is annular around the axis and has an intake passage formed therein that allows air to be introduced from the intake annular passage into the compressor casing; a partition plate located within the intake annular passage in a region opposite to the intake passage with respect to the axis; and a plurality of struts located within the intake passage, arranged in a circumferential direction with respect to the axis, wherein the bell mouth is located on the downstream side of the axis in the axial direction in which the axis extends, and is connected to the intake chamber casing so that the intake passage and the intake annular passage can communicate with each other. An intake casing, wherein the partition plate extends radially inward from the outer peripheral edge of the annular intake passage with respect to the axis, dividing the inside of the annular intake passage into one side and the other side in the circumferential direction; the plurality of struts each extend radially outward from the inner peripheral edge of the annular intake passage to the outer peripheral edge of the intake passage with respect to the axis; and the circumferential position of one of the plurality of struts is within ±2.5° in the circumferential direction with respect to the circumferential position of the partition plate.

2. An intake casing capable of introducing air into a compressor casing covering a compressor rotor rotatable around an axis, comprising: an intake chamber casing having an annular intake passage around the axis and an intake passage from the outer circumference side of the intake annular passage into which air can be introduced; a bell mouth that is annular around the axis and has an intake passage formed therein that allows air to be introduced from the intake annular passage into the compressor casing; a partition plate located within the intake annular passage in a region opposite to the intake passage with respect to the axis; and a plurality of struts located within the intake passage, arranged in a circumferential direction with respect to the axis, wherein the bell mouth is located on the downstream side of the axis in the axial direction from which the axis extends, and is connected to the intake chamber casing so that the intake passage and the intake annular passage can communicate with each other. An intake casing comprising: a partition plate extending radially inward from the outer peripheral edge of the annular intake passage with respect to the axis, dividing the annular intake passage into one side and the other side in the circumferential direction; a plurality of struts each extending radially outward from the inner peripheral edge of the annular intake passage to the outer peripheral edge of the intake passage with respect to the axis; and at least a portion of the circumferential region of one of the plurality of struts overlapping in the circumferential region with the circumferential region of the partition plate.

3. An intake casing according to claim 1 or 2, wherein the outer peripheral edge of the introduction annular passage is located radially outward from the outer peripheral edge of the intake passage at the connection position of the bell mouth with the intake chamber casing, and the partition plate extends radially outward from the outer peripheral edge of the introduction annular passage to a position within the position of the outer peripheral edge of the intake passage at the connection position.

4. An intake casing according to claim 1 or 2, wherein the rigidity of the partition plate is lower than the rigidity of each of the plurality of struts.

5. An axial flow compressor comprising: an intake casing according to claim 1 or 2; the compressor rotor; and the compressor casing.

6. A gas turbine comprising: an axial flow compressor according to claim 5; a combustor capable of generating combustion gas by burning fuel in air compressed by the axial flow compressor; and a turbine capable of being driven by the combustion gas.

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