TURBINE BLADE AND TURBINE

Abstract

A turbine blade with an internally cooled turbine blade airfoil, in which a hollow space is divided by rib elements in at least one cooling channel carrying a coolant, wherein a recess of material, which is arranged next to at least one rib element on a turbine blade airfoil wall, is embodied such that tensions occurring within the turbine blade airfoil can be reduced in a region surrounding the at least one rib element.

Claims

1.-12. (canceled)

13. A turbine blade comprising: an internally cooled turbine blade airfoil, in which a cavity is divided by at least one rib element into at least one cooling duct conveying coolant, wherein the rib element in question extends longitudinally as far as a rib element end that has a free end in the cooling duct, wherein a material recess arranged next to the rib element end of the rib element in question is configured such that stresses arising within the turbine blade airfoil are reducible in a region surrounding the at least one rib element, wherein the material recess is arranged on an inner side of the turbine blade airfoil wall.

14. The turbine blade as claimed in claim 13, wherein the material recess is arranged in a region surrounding the rib element end that has a free end in the cooling duct.

15. The turbine blade as claimed in claim 13, wherein the rib element end comprises a head side and the material recess is arranged next to the head side such that the material recess is arranged in an imaginary extension of the rib element along its longitudinal extent.

16. The turbine blade as claimed in claim 13, wherein the material recess is arranged on a turbine blade airfoil wall, spaced apart from the at least one rib element by less than 30 mm.

17. The turbine blade as claimed in claim 13, wherein the material recess is configured as at least a partial reduction in the thickness of a turbine blade airfoil wall.

18. The turbine blade as claimed in claim 13, wherein the material recess is configured as at least a concave hollow in a turbine blade airfoil wall.

19. The turbine blade as claimed in claim 13, wherein the material recess is configured on the internal side of a turbine blade airfoil wall.

20. The turbine blade as claimed in claim 13, wherein the material recess is arranged on the front side wall of the turbine blade airfoil.

21. The turbine blade as claimed in claim 13, wherein the base area shape of the material recess is circular or oval.

22. The turbine blade as claimed in claim 13, wherein the base area shape of the material recess is straight and elongate or curved and elongate.

23. The turbine blade as claimed in claim 13, wherein the material recess is arranged in a reversal region of the cooling duct.

24. A turbine, comprising: at least one turbine stage comprising a multiplicity of turbine blades, wherein the at least one turbine stage comprises a multiplicity of turbine rotor blades and/or turbine stator vanes as per a turbine rotor blade as claimed in claim 13.

25. The turbine as claimed in claim 24, wherein the turbine is a gas turbine.

26. The turbine blade as claimed in claim 13, wherein the material recess is arranged on a turbine blade airfoil wall, spaced apart from the at least one rib element by less than 20 mm.

27. The turbine blade as claimed in claim 13, wherein the material recess is arranged on a turbine blade airfoil wall, spaced apart from the at least one rib element by less than 10 mm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In the drawing:

[0037] FIG. 1 shows, schematically, a partial view of a turbine blade airfoil, in longitudinal section, with a rib element bounding a cooling duct, a material recess being formed on the inner side of the turbine blade airfoil in front of the rib element end thereof; and

[0038] FIG. 2 shows, schematically, a cross section through the turbine blade shown in FIG. 1.

DETAILED DESCRIPTION OF INVENTION

[0039] The turbine blade 1 in each case at least partially depicted in both FIGS. 1 and 2 is a rotor blade 2 of a hot gas turbine (not shown here).

[0040] The turbine blade 1 has an internally cooled turbine blade airfoil 3, the inner side 4 of the front side wall 5 of the turbine blade airfoil 3 being shown here (FIG. 1).

[0041] As shown in the illustration of FIG. 1, a leading edge region 6 of the turbine blade airfoil 3 is on the right-hand side. On the left-hand side is, accordingly, a trailing edge region 7 of the turbine blade airfoil 3, on which there is a multiplicity of cooling air exit bores 8 (numbered only by way of example). In particular in FIG. 2, the trailing edge region 7 is shown only partially.

[0042] In any case, the turbine blade airfoil 3 has a cavity 10, wherein in this case this cavity 10 is illustrated in FIG. 1 only partially by the inner side 4.

[0043] The cavity 10 contains in particular two rib elements 11 and 12 which form a highly convoluted cooling duct 13 with a sinuous cooling duct profile within the cavity 10. Along the convoluted cooling duct 13 or its sinuous cooling duct profile, cooling air as coolant can be conveyed through the turbine blade airfoil 3 in order to cool the latter from the inside.

[0044] In the case of the partially shown cooling duct 13, the cooling air coming from a root region, and thus from the direction of an opening 14 (shown only in FIG. 2) of a turbine blade root 15, flows essentially directly through a first cooling duct section 16 oriented toward the leading edge region 6, and a further cooling duct section 17 oriented toward the trailing edge region 7.

[0045] The sinuous cooling duct profile of the convoluted cooling duct 13 is, at least in the region of the partial view shown, configured in particular by the two rib elements 11 and 12, wherein the first rib element 11 spatially separates the two cooling duct sections 16 and 17 from one another.

[0046] In the present case, the first rib element 11 ends with its rib element end 24, defined by its head side 23, free in the cooling duct 13, specifically in the reversal region 19.

[0047] In particular in the region 28 surrounding the rib element end 24, there is the risk of critical thermomechanical stress states in particular in the transition regions between the first rib element 11 and the front side wall 5 of the turbine blade airfoil 3, and/or the rear side wall of the turbine blade airfoil 3, which can give rise to increased material fatigue there.

[0048] For that reason, a material recess 29 is formed on the inner side 4 in the region 28 surrounding the rib element end 24, in order to achieve an advantageous stress reduction in this region 28 surrounding the rib element end 24.

[0049] In this exemplary embodiment, the material recess 29 is arranged axially in front of the rib element end 24, at a distance of less than 10 mm from the head side 23.

[0050] Here, the material recess 29 is excavated as a concave, trough-shaped hollow 30 with an essentially oval base area (not explicitly numbered) on the inner side 4 of the front side wall 5 of the turbine blade airfoil 3.

[0051] In that respect, the material recess 29 also represents a partial reduction in the thickness of the front side wall 5 of the turbine blade airfoil 3.

[0052] Of course, a material recess 29 or partial reduction in wall thickness, which is identical or similar in this regard, can alternatively or additionally also be provided on the rear side wall (not shown here) of the turbine blade airfoil 3, at an identical, opposite location, or at an offset location.

[0053] Furthermore, other strengthening and guiding rib elements 37 (numbered only by way of example) and strengthening web elements 38 (numbered only by way of example) are also present and provide additional stabilization for the turbine blade airfoil 3 in the thinner trailing edge region 7.

[0054] Another strengthening rib 40, provided with bores 39, is provided in the leading edge region 6.

[0055] Although the invention has been described and illustrated in more detail by way of the preferred exemplary embodiment, the invention is not restricted by this disclosed exemplary embodiment and other variations can be derived herefrom by a person skilled in the art without departing from the scope of protection of the invention.