Assembly for a fluid flow machine

Abstract

A fluid-flow machine includes: a main flow path boundary and at least one row of relatively rotating blades with a gap existing between blade ends and the main flow path boundary. At least one secondary flow duct having one opening each is provided in the main flow path boundary at ends spaced apart in the flow direction, such that the secondary flow duct is connected to the main flow path via the two openings. The structural assembly has at least one support component and at least one insertion component. The support component includes a recess extending in the circumferential direction that receives the at least one insertion component such that the support component surrounds the at least one insertion component largely on its sides not facing the main flow path, and where the insertion component completely surrounds or forms at least one secondary flow duct.

Claims

1. A structural assembly for a fluid-flow machine comprising: a main flow path boundary confining a main flow path of a fluid-flow machine, where a row of blades each with one blade end is arranged in the main flow path, where a gap exists between the blade ends of the row of blades and the main flow path boundary, and where there is a rotating relative movement between the blades of the row of blades and the main flow path boundary, and a secondary flow duct, having first and second openings in the main flow path boundary at ends spaced apart in a main flow direction of the main flow path, such that the secondary flow duct is connected to the main flow path via the first and second openings, wherein the secondary flow duct is a one-way duct, such that fluid flows into the secondary flow duct through the first opening and fluid exits the secondary flow duct through the second opening, wherein the structural assembly includes a support component and an insertion component, where the support component includes at least one face forming the main flow path boundary and includes a recess in the main flow path boundary, the recess extending in an axial direction with respect to the main flow direction and extending in a circumferential direction, the recess being formed in an area radially adjacent a single row of blades and comprising an upstream side, a downstream side and a center side parallel to the main flow path boundary therebetween and receiving the insertion component such that the support component surrounds the insertion component largely on sides of the insertion component not facing the main flow path and the support component completely houses the insertion component within the recess, and where the insertion component completely surrounds or forms the secondary flow duct, wherein the insertion component surrounds the secondary flow duct so completely that all wetted surfaces of the secondary flow duct are associated with the insertion component in an undivided manner, and the secondary flow duct is contained within the recess in the support component; a further complete or partial ring adjoining the insertion component on a side facing the main flow path, the further complete or partial ring including an abradable coating on at least parts of a face of the further complete or partial ring facing the main flow path; wherein the abradable coating is a single piece component and the first and second openings of the secondary flow duct each are arranged in an area outside an axial extent of the abradable coating; wherein the first and second openings of the secondary flow duct are arranged upstream and downstream, respectively, of an axial extent of the blade ends.

2. The structural assembly in accordance with claim 1, wherein a face of the insertion component forms at least a portion of the main flow path boundary.

3. The structural assembly in accordance with claim 2, wherein the support component is an annular casing of a fluid-flow machine and encloses the insertion component from the outside.

4. The structural assembly in accordance with claim 2, wherein the support component is a half-shell casing of a fluid-flow machine and encloses the insertion component from the outside.

5. The structural assembly in accordance with claim 2, wherein the support component has an annular configuration on a hub of a fluid-flow machine and holds the insertion component from the inside.

6. The structural assembly in accordance with claim 2, wherein the support component has a semi-annular configuration on a hub of a fluid-flow machine and holds the insertion component from the inside.

7. The structural assembly in accordance with claim 2, wherein the insertion component is a complete ring or a ring sector.

8. The structural assembly in accordance with claim 1, wherein the support component is an annular casing of a fluid-flow machine and encloses the insertion component from the outside.

9. The structural assembly in accordance with claim 1, wherein the support component is a half-shell casing of a fluid-flow machine and encloses the insertion component from the outside.

10. The structural assembly in accordance with claim 1, wherein the support component has an annular configuration on a hub of a fluid-flow machine and holds the insertion component from the inside.

11. The structural assembly in accordance with claim 1, wherein the support component has a semi-annular configuration on a hub of a fluid-flow machine and holds the insertion component from the inside.

12. The structural assembly in accordance with claim 1, wherein the insertion component is a complete ring or a ring sector.

13. The structural assembly in accordance with claim 1, wherein the secondary flow duct is formed by an arrangement in which a single duct splits along its course into at least two ducts and forms a Y-configuration, where an inflow opening and a plurality of outflow openings are associated with the secondary flow duct.

14. The structural assembly in accordance with claim 1, wherein the secondary flow duct is formed by an arrangement in which at least two ducts converge into one duct, where a plurality of inflow openings and one outflow opening are associated with the secondary flow duct.

15. The structural assembly in accordance with claim 1, wherein the insertion component is manufactured by a casting, sintering or printing production method.

16. The structural assembly in accordance with claim 1, wherein a shape and faces of the insertion component are designed such that the insertion component can be inserted into the support component in an axial direction of the fluid-flow machine and an additional component adjoins the support component in the axial direction and fixes the insertion component.

17. The structural assembly in accordance with claim 1, wherein an abradable coating is provided on at least parts of faces of the insertion component facing the main flow path, the insertion component being a ring sector or complete ring.

18. A fluid-flow machine having a structural assembly in accordance with claim 1.

19. The structural assembly in accordance with claim 1, wherein at least a portion of each of the first and second openings is positioned within an axial extent of the single row of blades.

Description

(1) The present invention is described in the following with reference to the figures of the accompanying drawing, showing several exemplary embodiments. In the drawing,

(2) FIG. 1A shows, in two views, a casing treatment of a rotor casing in the form of annular grooves in accordance with the state of the art,

(3) FIG. 1B shows, in two views, a casing treatment of a rotor casing in the form of slots in accordance with the state of the art,

(4) FIG. 2A shows, in meridional sectional view, an exemplary embodiment of a rotor casing of a fluid-flow machine having a secondary flow duct,

(5) FIG. 2B shows, in a three-dimensional view, an exemplary embodiment of a rotor casing of a fluid-flow machine having a secondary flow duct,

(6) FIG. 3A shows a first exemplary embodiment of a structural assembly for a fluid-flow machine forming a secondary flow duct,

(7) FIG. 3B shows a second exemplary embodiment of a structural assembly for a fluid-flow machine forming a secondary flow duct,

(8) FIG. 3C shows a third exemplary embodiment of a structural assembly for a fluid-flow machine forming a secondary flow duct,

(9) FIG. 3D shows a fourth exemplary embodiment of a structural assembly for a fluid-flow machine forming a secondary flow duct;

(10) FIG. 4 is a schematic view showing the support component as part of a hub; and

(11) FIG. 5 is a schematic view showing a semi-annular support component.

(12) Various casing treatments of a rotor casing according to the state of the art were described at the outset on the basis of FIGS. 1A and 1B.

(13) FIG. 2A shows an arrangement of a blade row 3 with free end and running gap 5 in the meridional plane established by the axial direction x and the radial direction r. The running gap 5 separates the blade tip from a component 2 associated with the main flow path on the hub or casing of the fluid-flow machine. The component 2 forms here a main flow path boundary 4 towards the main flow path.

(14) There is a rotating relative movement between the blade tip and the component 2 associated with the main flow path. The illustration thus applies equally for the following arrangements: 1) rotating blade on stationary casing, 2) stationary blade on rotating hub, 3) stationary blade on rotating casing, and 4) rotating blade on stationary hub.

(15) The main flow direction in the main flow path is indicated by an arrow A. Further blade rows can be located upstream and/or downstream of the blade row 3 with running gap. Inside the component 2 associated with the main flow path, a row of secondary flow ducts 1 distributed over the circumference is provided in the area of the running gap 5, said ducts having an opening at each of their ends (supply opening and discharge opening).

(16) The openings of the secondary flow ducts are located on the main flow path boundary 4. FIG. 2A shows the outline or projection of a single secondary flow duct 1 in the meridional plane (x-r). Viewed spatially, each duct 1 has a three-dimensional and spatially winding course, shown by way of example in FIG. 2B.

(17) It is pointed out that the cross-sectional shape of the secondary flow ducts 1 in FIG. 2B is illustrated as rectangular only by way of example. The cross-section of the secondary flow ducts 1 in other design variants can for example be designed without corners, in particular circular or elliptical.

(18) FIG. 3A shows a structural assembly in accordance with the present invention in the area of a blade row with running gap in the meridional view (x-r). The main flow direction in the main flow path of the fluid-flow machine, in which the structural assembly is provided, is indicated by an arrow A. The blade row is no longer shown here for the sake of a simpler illustration.

(19) In the structural assembly, at least one secondary flow duct 1 is provided which has two openings 111, 112 in main flow path boundary 4 and is connected via these openings to the main flow path. It is pointed out here that in the exemplary embodiment of FIG. 3A the secondary flow duct 1 is designed as a one-way path, having one opening through which fluid flows out of the main flow duct into the secondary flow duct and a second opening through which fluid exits the secondary flow duct. Through which of the openings 111, 112 fluid flows in, and through which of the openings 111, 112 fluid flows out, depends here on the precise positioning of the openings 111, 112 relative to the blades of the blade row 3 (cf. FIG. 2B).

(20) In alternative embodiments, it can be provided that at least one of the secondary flow ducts is formed by an arrangement in which a single duct splits along its course into at least two part-ducts and thereby forms a type of Y-configuration. In this case, an inflow opening and several outflow openings associated with the secondary flow duct are provided. See, for instance, FIG. 4. According to a further alternative embodiment, it can be provided that at least one of the secondary flow ducts is formed by an arrangement in which at least two ducts converge into one duct, with several inflow openings and one outflow opening then being associated with the secondary flow duct. See, for instance, FIG. 5. As noted in the paragraph above, which of the openings 111 and 112 are the inflow openings or the outflow openings depends on the positioning of the openings 111 and 112 relative to the blades, so the situations noted in this paragraph could also be shown by the other of FIG. 4 or FIG. 5 than noted above depending on the positioning of the openings relative to the blades.

(21) The structural assembly includes a support component 21 and an insertion component 22. A recess 210 running in the circumferential direction is provided in the support component 21 and receives the insertion component 22 along its circumference. The insertion component 22 (or, if several insertion components are provided, each of the insertion components) forms with some of its faces part of the outer main flow path boundary. If the structural assembly is alternatively arranged in the hub area of a fluid-flow machine, the insertion component forms in a corresponding manner with at least some of its faces part of the inner main flow path boundary of the main flow path of the fluid-flow machine.

(22) According to FIG. 3A, it is furthermore provided that the secondary flow duct 1 is provided in the insertion component 22, and only therein, meaning that the insertion component 22 completely surrounds the secondary flow duct 1, with all wetted surfaces of the secondary flow duct 1 and any further secondary flow ducts, if applicable, being associated with the insertion component 22 in undivided manner.

(23) The support component 21 can be part of the outward casing or of the inward hub of the fluid-flow machine and forms with some of its faces the main flow path boundary. In the exemplary embodiment shown, the support component 21 represents a part of the outward casing of the fluid-flow machine. In principle, the support component 21 can in particular be a part of the fluid-flow machine design in the following areas: part of a single-shell or multi-shell casing of blade rows or stages with fixed blade geometry, part of a single-shell or multi-shell casing of blade rows or stages with variable blade geometry, part of rotor drums, rotor disks or blisk modules (see FIG. 4 showing the support component 21 as part of a hub, with FIG. 5 showing the support component 21 as semi-annular, and which can be part of the hub or casing), part of inner shroud assemblies in the hub area of stator vanes.

(24) In the exemplary embodiment of FIG. 3A, the support component is designed as an annular casing of a fluid-flow machine or as a half-shell casing of a fluid-flow machine. With an appropriate arrangement in the hub area, it is for example designed annular on the hub of a fluid-flow machine or semi-annular on the hub of a fluid-flow machine.

(25) The insertion component 22 is designed in one exemplary embodiment as a complete ring placed inside the corresponding recess 210 of the structural component 21 extending in the circumferential direction. Alternatively, it is for example provided that the insertion component 22 is designed as a ring sector. It can be provided here that a plurality of secondary flow ducts are arranged along the circumference of the main flow path boundary, such that the insertion component 22 has a plurality of secondary flow ducts 1 in the circumferential direction.

(26) Due to the possible complexity of the secondary flow ducts 1, it can be provided that the insertion component 22 is manufactured by a casting, sintering or printing production method. It can be provided, as explained, that the insertion component 22 is manufactured as a complete ring or as a ring sector using the aforementioned methods.

(27) FIG. 3B shows a further exemplary embodiment of a structural assembly in the area of a blade row with running gap in the meridional view (x-r). In this exemplary embodiment, a recess 211 is provided in the support component 21 in such a way that it does not surround the insertion component 22 at all outer faces which are not part of the main flow path boundary. A further additional component 23 is therefore provided which is arranged in the axial direction (x) in front of the support component 21 and the insertion component 22 and has for example an annular shape with a face 230 facing the support component 21 and the insertion component 22. This arrangement allows the insertion component 22 to be pushed in the axial direction into the support component 21 in a simple manner (instead of in the radial direction as in the exemplary embodiment of FIG. 3A), and then to achieve axial positioning using the additional component 23. The additional component 23 here also forms faces which are part of the main flow path boundary.

(28) In the exemplary embodiment of FIG. 3B too, the secondary flow duct 1 is designed completely inside the insertion component 22.

(29) FIG. 3C shows a further variant of a structural assembly. The embodiment differs from the embodiment of FIG. 3B in that an abradable coating 6 is additionally provided directly on or in the insertion component 22, where it can be provided that at least one of the openings 111, 112 of the secondary flow duct 1 is located in an area in which the abradable coating 6 is arranged. It can be provided here that the abradable coating 6 is designed as a ring sector or complete ring on the insertion component 22 and here provides a face facing the main flow path. An abradable coating of this type is used to mesh with the blades 3 of a rotating blade row and to permit the running gap 5 to be minimized (cf. FIG. 2A).

(30) FIG. 3D shows a further exemplary embodiment of a structural assembly. Unlike in the exemplary embodiment of FIG. 3C, it is provided that the abradable coating 6 is designed in an intermediate ring 7, which is inserted into a corresponding recess 220 in the insertion component 22. The additional ring 7 can be designed here as a complete ring or partial ring. The abradable coating 6 is provided on this ring or partial ring 7 on its face facing the main flow path.

(31) In further embodiments of the present invention, the design solutions described with reference to the FIGS. 3A, 3B, 3C, 3D can be combined with one another. A further variant of the present invention for example provides that an abradable coating 6 is also used in the embodiment of FIG. 3A.

(32) The present invention, in its design, is not restricted to the exemplary embodiments presented above, which are only to be understood as examples.

(33) The shape and the embodiment of the secondary flow ducts and of the support component and the insertion component can for example be designed in a different manner than that shown.