Casing arrangement for a gas turbine

Abstract

The present invention relates to a gas turbine casing arrangement having a gas turbine casing element (10), a guide-vane ring with an outer ring (20), and a coated ring (30), which lies radially opposite a rotor grid (40) adjacent to the guide-vane ring, whereby an intermediate ring (50) by a downstream front face (51) engages behind an upstream stop (61; 61′) fixed in place on the casing element, and by an upstream front face (52) of a radial flange (53) of the intermediate ring engages behind a downstream stop (22) fixed in place on the outer ring, in order to secure the guide-vane ring axially at the gas turbine casing element in the direction of through-flow.

Claims

1. A gas turbine casing arrangement, comprising: a gas turbine casing element; a guide-vane ring with an outer ring; and a coated ring, which lies radially opposite a rotor grid adjacent to the guide-vane ring; wherein an intermediate ring, which, by a downstream front face engages behind an upstream stop fixed in place on the casing element, and by an upstream front face of a radial flange of the intermediate ring engages behind a downstream stop fixed in place on the outer ring, in order to axially secure the guide-vane ring at the gas turbine casing element in the direction of through-flow; wherein in an operating position, a surface area of the radial flange abuts the coated ring at a support wall disposed at a seal.

2. The gas turbine casing arrangement according to claim 1, wherein, in an installed position, a gap(s) is formed between the radial flange and the coated ring (30), in order to make possible a radially outward movement of the radial flange.

3. The gas turbine casing arrangement according to claim 1, wherein the radial flange forms an outer wall structure of a flow channel, in which the rotor grid is disposed.

4. The gas turbine casing arrangement according to claim 1, wherein the intermediate ring has an axial flange, which is disposed between its downstream and its upstream front faces, and is elastically deformed in an operating position.

5. The gas turbine casing arrangement according to claim 1, wherein the downstream front face is disposed at another radial flange of the intermediate ring, which is articulated tiltable at the gas turbine casing element.

6. The gas turbine casing arrangement according to claim 1, wherein the outer ring is fastened at the gas turbine casing element by spokes with radial play in the installed position.

7. The gas turbine casing arrangement according to claim 1, wherein the upstream stop fixed in place on the casing element is disposed at a securing ring, which is fastened detachably or non-detachably in the gas turbine casing element; or in a peripheral groove of a bayonet hook; or is disposed at an additional gas turbine casing element joined detachably or non-detachably to the gas turbine casing element.

8. The gas turbine casing arrangement according to claim 7, wherein the securing ring is radially supported at the coated ring, at least in an operating position.

9. The gas turbine casing arrangement according to claim 1, wherein the coated ring is radially supported at the intermediate ring.

10. The gas turbine casing arrangement according to claim 9, wherein the coated ring is supported radially at the intermediate ring by an axial region, which is particularly upstream, and is joined to the gas turbine casing element by another axial region, which is particularly downstream.

11. The gas turbine casing arrangement according to claim 1, further comprising a gas passage from a surface of the intermediate ring facing the guide-vane ring to a surface of the intermediate ring lying opposite the latter.

12. The gas turbine casing arrangement according to claim 1, wherein the coated ring is segmented and/or the guide-vane ring is formed integrally.

13. The gas turbine casing arrangement according to claim 1, wherein at least one additional, downstream guide-vane ring is disposed in the gas turbine casing element, or in that the guide-vane ring is a most downstream guide-vane ring in the gas turbine casing element.

14. The gas turbine casing arrangement of claim 1, wherein the guide-vane ring is secured in the direction of through-flow axially at the gas turbine casing element of the gas turbine casing arrangement where the intermediate ring, by its downstream front face, engages behind the upstream stop fixed in place on the casing element, and by its upstream front face of its radial flange engages behind the downstream stop fixed in place on the outer ring.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Additional advantageous enhancements of the present invention is further discussed in the following description of preferred embodiments. For this purpose and partially schematized:

(2) FIG. 1 shows a gas turbine casing arrangement of a gas turbine according to an embodiment of the present invention in a meridian section in an installed position;

(3) FIG. 2 shows the gas turbine casing arrangement of FIG. 1 in an operating position; and

(4) FIG. 3 shows a gas turbine casing arrangement of a gas turbine according to another embodiment of the present invention in a representation corresponding to FIG. 1;

DETAILED DESCRIPTION OF THE INVENTION

(5) FIG. 1 shows a gas turbine casing arrangement according to an embodiment of the present invention in a meridian section, i.e., a section that contains an axis of rotation of the gas turbine (horizontal in FIG. 1), in an installed position.

(6) The gas turbine casing arrangement in FIG. 1 has a gas turbine casing element 10, which is only partially shown, a guide-vane ring with an outer ring 20, as well as a coated ring 30, which lies radially opposite (from bottom to top in FIG. 1) a rotor grid successively adjacent to the guide-vane ring in the direction of through-flow (from left to right in FIG. 1), the rotor grid having an outer shroud 40. The coated ring 30 has a honeycomb seal 31 surrounding the rotor grid radially outside.

(7) In addition, the gas turbine casing arrangement has an intermediate ring 50, which engages behind an upstream stop 61 fixed in place on the casing by a downstream front face 51 and a downstream stop 22 fixed in place on the outer ring by an upstream front face 52 of a radial flange 53 of the intermediate ring 50, in order to secure the guide-vane ring axially at the gas turbine casing element in the direction of through-flow (from left to right), whereby, in the installed position shown in FIG. 1, a gap s is formed between the radial flange 53 and the coated ring 30, in order to make possible a radially outward movement of the radial flange 53 (toward the top in FIG. 1).

(8) FIG. 2 shows the gas turbine casing arrangement of FIG. 1 in an operating position: after the radial flange 53 has expanded radially as a consequence of heating brought about by operation, in the operating position, it abuts the surface of a support wall 32 of the coated ring 30, which is disposed at its seal 31 surrounding the rotor grid radially outside, and is supported at this support wall 32. In the overview of FIGS. 1, 2, one also recognizes the radial and axial displacement of the outer ring 20 as a consequence of thermal stress and mechanical stress related to flow.

(9) The radial flange 53 forms an outer wall structure of a flow channel 70, in which the rotor grid is disposed. In this way, during operation, the radial flange is loaded or stressed by the hot exhaust gas flowing through the flow channel 70 and the rotor grid.

(10) The intermediate ring 50 has an axial flange 55, which is disposed between its downstream and its upstream front surfaces 51, 52, and at which the radial flange 53 of the intermediate ring is disposed. In the meridian section of FIG. 1, the latter has a crease or line in order to maintain the angle at which the radial flange 53 inclines upon radial expansion.

(11) The downstream front face 51 is disposed at another radial flange 54 of the intermediate ring 50, which is articulated tiltable at the gas turbine casing element 10. As is shown by the overview of FIGS. 1 and 2, the additional radial flange 54 of the intermediate ring rotates around a contact point at the stop 61 fixed in place on the casing element and is supported rotatable thereto at the stop, in the meridian section of FIGS. 1, 2. For this, the additional radial flange 54 of the intermediate ring has, on its side lying opposite the downstream front face 51 of the intermediate ring or opposite the upstream stop 61 fixed in place on the casing element (i.e., on the left in FIG. 1), a rounding and/or an axial play relative to the gas turbine casing element 10, which, in the meridian section, makes possible or permits a rotation of the cross section of the additional radial flange 54 supported at the stop 61 fixed in place on the casing element.

(12) In the installed position (see FIG. 1) and in the operating position (see FIG. 2), a contact surface is disposed between the upstream front face 52 of the radial flange 53 of the intermediate ring and the downstream stop 22 fixed in place on the outer ring in the direction of through-flow axially downstream and radially inside, i.e., on the right and bottom in FIG. 1, from a contact surface between the downstream front face 51 of the intermediate ring and the upstream stop 61 fixed in place on the casing element, in order to thus impart a corresponding torque for tilting the additional radial flange of the intermediate ring.

(13) The outer ring 20 is fastened at the gas turbine casing element 10 by a plurality of radial spokes 11, 21 with radial play between the radially inward extending projections 11 fixed in place on the casing element and the radially outward extending projections 21 fixed in place on the outer ring, in the installed position, the projections securing the outer ring 20 at the gas turbine casing element 10 in the peripheral direction.

(14) In the embodiment of FIGS. 1, 2, the guide-vane ring is a guide-vane ring of an internal stage. Therefore, the upstream stop 61 fixed in place on the casing element is disposed at a securing ring 60, which is fastened by friction fit in the gas turbine casing element 10. In a modification (not shown), the upstream stop fixed in place on the casing element is instead disposed in a peripheral groove of a bayonet hook. For this purpose, in FIG. 1, the securing ring 60 is thought of as formed integrally with the gas turbine casing element 10, whereby the additional radial flange 54 and the securing ring 60 then have corresponding gaps in the peripheral direction (perpendicular to the plane of the drawing of FIG. 1), so that the additional radial flange can be shifted first axially counter to the direction of through-flow and then can be rotated in the peripheral direction, so that its front face 51 then engages behind the stop 61.

(15) The discussed securing ring 60 is supported radially at the coated ring 30 in the operating position (see FIG. 2). The coated ring 30 in its turn is supported radially at the intermediate ring 50 both in the installed position and in the operating position from radially outside (from the top in FIG. 1) by an upstream (on the left in FIGS. 1, 2) axial region. Its opposite-lying, downstream axial region, which is not shown in FIGS. 1, 2, is joined directly or indirectly with the gas turbine casing element.

(16) The upstream axial region of the coated ring, which is supported radially at the intermediate ring from radially outside, has play or free space, radially outward (toward the top in FIGS. 1, 2) in particular a radial gap relative to the gas turbine casing element 10.

(17) As shown in the overview of FIGS. 1, 2, upon a radial expansion of its radial flange 53 as a consequence of the support of the upstream axial region of the coated ring 30, the intermediate ring 50 guides the latter radially outward with it. In this way, in particular, a radial gap can be kept constant, at least substantially, relative to the rotor grid 40 expanding thermally radially outward or relative to the fins on its outer shroud.

(18) FIG. 3 shows a gas turbine casing arrangement of a gas turbine according to another embodiment of the present invention in a representation corresponding to FIG. 1. Features corresponding to each other are identified by identical reference numbers, so that reference is made to the preceding description, and only differences will be discussed in the following.

(19) In the embodiment of FIG. 3, the guide-vane ring is the last or a downstream guide-vane ring of the casing element and is disposed at a modular interface between a turbine mid-frame and a low-pressure turbine. The upstream stop 61′ fixed in place on the casing element is disposed in this case at another gas turbine casing element 60′ that is part of a casing of the low-pressure turbine, and which is joined to the gas turbine casing element 10 that is part of a turbine mid-frame.

(20) Although exemplary embodiments were explained in the preceding description, it shall be noted that a plurality of modifications is possible. In addition, it shall be noted that the exemplary embodiments only involve examples that in no way shall limit the scope of protection, the applications and the structure. Rather, a guide is given to the person skilled in the art by the preceding description for implementing at least one exemplary embodiment, whereby diverse changes, particularly with respect to the function and arrangement of the described components, can be carried out without departing from the scope of protection, as results from the claims and combinations of features equivalent to these.