Retaining element for retaining a heat shield tile and method for cooling the supporting structure of a heat shield

Abstract

A retaining element (22, 54) for retaining a heat shield tile on a supporting structure: A fastening section (23) fastened to the supporting structure. A retaining section (24) having a retaining head (25), which engages an engagement device on the heat shield tile. The fastening section (23) top side (28) faces the cold side of the heat shield tile when the retaining section engages the heat shield tile. Scaling of the supporting structure due to the entry of hot gas can be avoided particularly effectively by means of the retaining element. At least one cooling-air passage (34, 55) arranged in the fastening section (23) has an inlet opening (35, 68) and at least one outlet opening (37, 38, 62) which is arranged in a lateral surface (32) and/or on the top side (28) of the fastening section. Cooling air, which enters the inlet opening (35, 68) and exits from the at least one outlet opening, can be conducted in a respective outflow direction (50, 51, 59, 63, 61) by the cooling-air passage, which outflow is parallel to the cold side and avoids impingement cooling of the heat shield tile. The fastening section is arranged on the supporting structure such that the cooling-air passage (34, 55) corresponds to at least one cooling-air channel (45) in the supporting structure.

Claims

1. A retaining element for retaining a heat shield tile on a support structure of a gas turbine engine component, the retaining element comprising: the support structure of the gas turbine engine component, a fastening section configured to be fastened on the support structure in a fastening groove, the fastening section comprises at least one tile retaining section with a retaining head configured for engaging the heat shield tile, the fastening section further comprises an elongated baseplate, the at least one tile retaining section is arranged toward one end of the elongated baseplate, and the fastening section having an adjoining end region facing away from the at least one tile retaining section, and an upper side of the fastening section located to face a cold side of the heat shield tile; the fastening section in the adjoining end region on the upper side of the fastening section comprises a projection, and the projection projects from the elongated baseplate in a direction perpendicular to a surface of the support structure towards the heat shield tile and away from the at least one tile retaining section; at least one cooling air passage arranged in the fastening section in a region of the projection, the at least one cooling air passage comprising an inlet opening communicating into at least one discharge opening which is arranged in at least one of a lateral face of and at the upper side of the fastening section; the at least one cooling air passage configured for supplying cooling air flow in an outflow direction and the cooling air flow flows through the at least one discharge opening, wherein the outflow direction comprises a velocity component which is parallel to the cold side of the tile and avoids impingement cooling of the heat shield tile wherein the heat shield is retained by the at least one tile retaining section; and the fastening section is arranged on the support structure of the gas turbine component such that the inlet opening of the at least one cooling air passage aligns with a cooling air channel in a bottom of the fastening groove.

2. The retaining element as claimed in claim 1, further comprising the fastening section extends in a step-like offset manner in the region of the projection.

3. The retaining element as claimed in claim 1, wherein the at least one cooling air passage comprises a cooling air hole, arranged in the fastening section, and comprises the at least one discharge opening which is arranged in at least one lateral face of the projection.

4. The retaining element as claimed in claim 3, further comprising the projection is stepped with the lateral face pointing in the direction of the at least one tile retaining section, and the at least one discharge opening arranged in the lateral face.

5. The retaining element as claimed in claim 3, wherein the end region includes a blocking plate in a stepped offset manner on the baseplate defining the projection as stepped by means of the blocking plate in the upper side of the fastening section, wherein the at least one cooling air passage is defined at least by an underside of the blocking plate and a portion of an end face of the baseplate which extends beneath the blocking plate.

6. A heat shield for a combustion chamber of a gas turbine comprising: a support structure of a gas turbine component, for supporting a plurality of heat shield tiles to be detachably fastened on the support structure of the gas turbine component with retaining elements, wherein each heat shield tile of the plurality of heat shield tiles has a cold side facing the support structure of the gas turbine component and a hot side opposite the cold side that is acted upon by a hot medium; each retaining element of the retaining elements has a retaining section configured for fastening on one of the plurality of heat shield tiles and has a fastening section configured for being fastened on the support structure of the gas turbine component in a fastening groove, at least one cooling air channel is provided in the support structure of the gas turbine component for protection against hot gases; at least one retaining element of the retaining elements is the retaining element as claimed in claim 1; and wherein the at least one cooling air channel in the support structure of the gas turbine component is communicating with the retaining element such that with the plurality of heat shield tiles fastened on the support structure of the gas turbine component, cooling air flowing from the cooling air channel at least partially enters the inlet opening of the at least one cooling air passage.

7. A combustion chamber which is lined with a heat shield, as claimed in claim 6.

8. A gas turbine with a combustion chamber as claimed in claim 7.

9. A method for cooling a support structure of a gas turbine heat shield comprised of a plurality of heat shield tiles; the method comprising: detachably fastening the heat shield tiles on the support structure of a gas turbine heat shield with retaining elements and guiding at least one retaining element of the retaining elements by a fastening section in a fastening groove extending in the support structure; and wherein the at least one retaining element of the retaining elements is the retaining element as claimed in claim 1, and is positioned in the fastening groove in such a way that the inlet opening of the at least one cooling air passage which is arranged in the fastening section and the at least one discharge opening of the cooling air channel which is arranged in a bottom of the groove align with each other so that cooling air discharging from the the at least one discharge opening of the cooling air channel is directed at least partially from the support structure of a gas turbine heat shield along the at least one cooling air passage formed by the fastening section of the retaining element to at least the upper side and/or the lateral face of the fastening section and configured to impress a flow direction upon the cooling air by means of the at least one cooling air passage, wherein the impressed flow direction is selected to avoid impingement cooling of the heat shield tile.

10. The method as claimed in claim 9, further comprising directing the cooling air being discharged from the at least one cooling air passage onto at least one region of the support structure of a gas turbine heat shield on which a fastening section of a retaining element is fastened.

11. The method as claimed in claim 10, further comprising directing the cooling air flowing along the at least one cooling air passage onto an edge of the fastening groove.

12. A retaining element for retaining a heat shield tile on a support structure of a gas turbine engine component, the retaining element comprising: the support structure of the gas turbine engine component a fastening section configured to be fastened on the support structure, the fastening section comprises at least one tile retaining section with a retaining head configured for engaging the heat shield tile; an upper side of the fastening section located to face a cold side of the heat shield tile; the fastening section further comprises an elongate baseplate, the at least one tile retaining section is arranged toward one end of the baseplate; the upper side of the fastening section comprises a projection and the projection projects from the base plate in a direction perpendicular to a surface of the support structure of the gas turbine engine component towards the heat shield tile and away from the at least one tile retaining section; at least one discharge opening directed laterally from the fastening section for flowing of cooling air flow; at least one cooling air passage arranged in the fastening section, the at least one cooling air passage comprises an inlet opening communicating into at least one of the discharge openings directed laterally; the at least one cooling air passage configured for supplying cooling air flow in an outflow direction and the cooling air flow is directed to be impressed upon the cooling air flow from the at least one discharge opening, wherein the outflow direction comprises a velocity component which is parallel to the cold side of the tile and avoids impingement cooling of the heat shield tile which is then retained by the at least one tile retaining section; and the fastening section is arranged on the support structure of the gas turbine engine component such that the inlet opening of the at least one cooling air passage aligns with a cooling air channel in the support structure of the gas turbine engine component.

13. A retaining element as claimed in claim 12, wherein the projection has lateral faces with the at least one discharge opening.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a schematic view of a gas turbine according to the prior art,

(2) FIG. 2 shows a perspective, schematic view of a retaining element according to the invention according to a first exemplary embodiment,

(3) FIG. 3 shows a sectional view of the retaining element shown in FIG. 2 arranged on a support structure of heat shield according to the invention,

(4) FIG. 4 shows a perspective, schematic view of a retaining element according to a second exemplary embodiment of the invention, and

(5) FIG. 5 shows a sectional view of the retaining element shown in FIG. 4 arranged on a support structure of a heat shield according to the invention,

(6) FIG. 6 shows a heat shield as held in the retaining element in FIG. 5.

DESCRIPTION OF EMBODIMENTS

(7) FIG. 1 shows a schematic sectional view of a gas turbine 1 according to the prior art. Inside, the gas turbine 1 is a rotor 3, rotatably mounted around a rotational axis 2, with a shaft 4, which together are also referred to as a turbine rotating component. There are arranged in sequence along the rotor 3 an intake housing 6, a compressor 8, a combustion system 9 including a plurality of combustion chambers 10 which comprise in each case a combustion arrangement 11 and a housing 12, a turbine 14 and an exhaust gas housing 15. The housing 12 is lined with a heat shield (not shown) for protection against hot gases.

(8) The combustion system 9 communicates with, for example an annular hot gas passage. A plurality of series-connected turbine stages form the turbine 14 there. Each turbine stage is formed from blade rings. A row formed from rotor blades 18 follows a row formed from stator blades 17 in the hot gas passage, as seen in the flow direction of a working medium. The stator blades 17 in this case are fastened on an inner housing of a stator 19, whereas the rotor blades 18 of a row are attached on the rotor 3 by means of a turbine disk, for example. A generator (not shown), for example, may be coupled to the rotor 3.

(9) During operation of the gas turbine, air is drawn in by the compressor 8 through the intake housing 6 and is compressed. The compressed air which is made available at the turbine-side end of the compressor 8 is directed to the combustion system 9 and in the region of the combustion arrangement 11 is mixed with fuel there. The mixture is then combusted with the aid of the combustion arrangement 11, forming a working gas flow in the combustion system 9. From there, the working gas flow flows along the hot gas passage past the stator blades 17 and the rotor blades 18. On the rotor blades 18, the working gas flow expands, transmitting an impulse so that the rotor blades 18 drive the rotor 3 and this drives the generator (not shown) which is coupled to it.

(10) FIG. 2 shows a retaining element 22 according to the invention according to a first exemplary embodiment in a perspective view. The exemplary embodiment of the retaining element 22 comprises a rectangular, plate-like fastening section 23, adjoining one end face of which at right angles is a retaining section 24. The retaining section 24 comprises a retaining head 25 which is designed for engaging an engagement device such as a peripheral groove 73 provided on the heat shield tile 72 (FIG. 6). The fastening section 23 has an upper side 28. For fastening the retaining element 22 on a support structure (not shown), the fastening section 23 is widened in certain sections. This widening of the fastening section 23 is also referred to as a shoe 29.

(11) A projection 30, arranged on the upper side 28 of the fastening section 23 and projecting away from the retaining section, adjoins the shoe 29 so that the fastening section is thickened in the region of the projection 30. The projection 30 is of a step-like design, with one lateral face 32 pointing in the direction of the retaining section 24. Within the scope of the invention, the term lateral face of the fastening section 23 also includes the lateral face 32.

(12) The depicted fastening section 23 comprises a cooling air passage which extends through the thickened region of the fastening section 23. The cooling air passage 34 therefore communicates with the projection 30 which is formed on the upper side of the fastening section. The cooling air passage 34 comprises an inlet opening 35 and two discharge openings 37 and 38. The discharge openings 37, 38 are arranged in opposite lateral faces 32, 39 of the fastening section. The depicted cooling air passage 34 is a cooling air hole which has a discharge opening 38 arranged in the lateral face 32 of the projection 30 pointing in the direction of the retaining section 24 and a discharge opening 37 arranged in the opposite lateral face 39.

(13) A cooling air flow, which enters the cooling air passage 34 through the inlet opening 35, is split into two flows as a result of the course of the T-shaped cooling air passage 34 and discharges from the cooling air passage 34 through the discharge openings 37 and 38. During the throughflow of the cooling air passage 34, an outflow direction, which extends parallel to the upper side of the fastening section 23, is impressed upon the cooling air. An impingement cooling of structures (not shown) which are arranged above the retaining element 22 is avoided as a result of this.

(14) FIG. 3 shows a detail of a heat shield 42 according to the invention with a support structure 43 below and a retaining element 22 which is fastened on the support structure and designed according to FIG. 2. The retaining element 22, by its fastening section 23, butts against the support structure 43 and has a retaining section 24 for retention of a heat shield tile (not shown). In this position, the upper side 28 of the fastening section 23 faces a cold side of a heat shield tile (not shown) which is retained by the retaining section 24.

(15) In the depicted sectional view, the cooling air passage 34, which is described in more detail in connection with FIG. 2, is shown in a longitudinal section. The inlet opening 35 of the cooling air passage 34 aligns with a cooling air channel 45 which is arranged in the support structure. Therefore, the fastening section 23 is arranged on the support structure 43 in such a way that the cooling air passage 34 communicates with a cooling air channel 45 which is arranged in the support structure 43. In the figure, two flow paths 47 and 48, along which some of the cooling air flowing from the cooling air channel 45 passes through the cooling air passage 34, are sketched in by way of example. Outflow directions 50 and 51 are impressed upon the cooling air by means of the cooling air passage 34 and comprises a velocity component which is parallel to the cold side of a heat shield tile retained by the retaining element and avoids an impingement cooling of the heat shield tile.

(16) FIG. 4 shows a retaining element 54 according to the invention according to a second exemplary embodiment. The retaining element 54 differs from the retaining element shown in FIG. 2 by a different design of the cooling air passage 55. The fastening section 23 in this case comprises an elongate baseplate 57, adjoining one end face of which is the retaining section 24 and on the other end face 58 of which is arranged a blocking plate 60 which is offset in relation to the baseplate 57 in the direction of the heat shield tile (not shown). As a result, a step-like projection 30 is formed in the upper side of the fastening section 23 and the fastening section 23 extends in a step-like offset manner. The cooling air passage 55 is delimited by the underside of the blocking plate 60 and the end face 58 of the baseplate 57 which extends beneath the blocking plate. The cooling air passage 55 therefore comprises a discharge opening 62 which is arranged in the lateral faces of the fastening section 23 and circumferentially extends around the end of said fastening section 23. An outflow direction 59, 61, 63 is impressed upon the cooling air flow when passing through the cooling air passage 55 and extends parallel to the cold side of a heat shield tile which is retained by the retaining section.

(17) FIGS. 5 and 6 show a detail of a heat shield 64 according to the invention with a support structure 43 and a retaining element 22, 54, fastened on the support structure, which is designed according to FIG. 4. The retaining element retains a respective one of a plurality of heat shield tiles 22. The heat shield tile includes a peripheral retention groove 73 on at least two sides and the retaining head 25 extends into the groove 73 to retain the tile 72.

(18) The fastening section 23, including the baseplate 57 and the blocking plate 60, is fastened on the support structure 43 in such a way that a cooling air channel 45 communicates with the cooling air passage 55. By means of the cooling air passage 55, outflow directions 59, 61, 63 are impressed upon the cooling air which flows from the cooling air channel 45 along the exemplarily sketched-in flow paths 65 and 66 into the inlet opening 68 of the cooling air passage 55 and out of the discharge opening 62. The outflow direction in the depicted exemplary embodiment points parallel to the cold side 71 of a heat shield tile 72 which is retained by the retaining section 24. The depicted exemplary embodiment is particularly well suited for cooling the edges of a fastening groove (not shown) in which the retaining element 54 is fastened on the support structure.

(19) Within the scope of the invention, a direction which is parallel to the cold side of the heat shield tile is synonymous with a direction which is parallel to the surface of the support structure facing the heat shield tile. Surface irregularities of the support structure are not taken into consideration in this case.