Insert element for closing an opening inside a wall of a hot gas path component of a gas turbine and method for enhancing operational behaviour of a gas turbine

1. An insert element for closing an opening inside a wall of a hot gas path component of a gas turbine, the insert comprising:

a disc body with a surface (S) configured to face the opening, said surface provides at least one first area which projects in a direction perpendicular to the surface beyond at least one second area of said surface, the at least one second area framing the at least one first area,

the at least one first area is encompassed by a circumferential edge corresponding in form and size to said opening such that the circumferential edge and the opening contour limit a gap at least in some areas while the at least one second area contacts directly or indirectly the wall of the hot gas path component at a rear side facing away from the hot gas path, and

the disc body includes a first functional layer-system, including at least one layer made of heat resistant material, defining the first area of the surface (S) as planar.

2. The insert element according to claim 1 ,

wherein the at least one layer of heat resistant material is made of a thermal barrier coating (TBC).

3. The insert element according to claim 1 ,

wherein a second layer-system being in direct or indirect flatly contact to said first layer-system at a side facing away from the first area and includes means for cooling the first layer-system.

4. The insert element according to claim 1 ,

wherein the first layer-system is fixed to the second layer-system by a heat and oxidation resistant bond coat layer.

5. The insert element according to claim 3 ,

wherein the second layer-system comprises at least one layer made of heat resistant material providing at least one cooling channel for cooling the first layer-system.

6. The insert element according to claim 5 ,

wherein the second layer-system comprises at least two layers made of heat resistant material each layer providing at least one through hole, which are arranged such that the at least two through holes are fluidly connected.

7. The insert element according to claim 3 ,

wherein a third layer-system system being in direct or indirect flatly contact to said second layer-system at a side facing away from the first layer-system and including an acoustical damper having at least one acoustic access to the hot gas path.

8. The insert element according to claim 7 ,

wherein the acoustical damper is a Helmholtz damper being defined by at least one cavity inside the third layer-system having direct access to the hot gas path by at least one hollow channel, having a channel opening at the first area of the surface and merges into the cavity.

9. The insert element according to claim 1 ,

wherein the at least one first area of the disc body is formed and arranged in relation to the at least one second area such that the surface of the at least one first area is arranged in the opening and flush with the wall of the hot gas path component while the at least one first area of the disc body closes the opening of the hot gas path component and the at least one second area faces the rear side of the wall.

10. The insert element according to claim 1 ,

wherein the hot gas path component is a wall enclosing the combustor and/or the hot gas path which adjoins the combustor of the gas turbine.

11. The insert element according to claim 1 ,

wherein the opening is a machined aperture which opening contour is adapted to the circumferential edge of the at least one first area of the surface (S) of the disc body.

12. Method for enhancing operational behavior of a gas turbine having a hot gas path component encircling at least parts of a combustor and/or a hot gas path adjoining to said combustor, comprising:

providing an opening into the wall of said hot gas path component at a location of high thermal and/or mechanical stress,

inserting the insert element according to claim 1 from outside of said hot gas path component into the opening inside the wall of the a hot gas path component and

fixing and sealing the insert element to said wall by welding and/or brazing.

13. Method according to claim 12 ,

wherein said opening being provided during production process of the hot gas path component by molding or as part of a post-processing at the wall of the hot gas path component by a cutting and/or drilling process.