Cooling system for actively cooling a turbine blade

Abstract

A cooling system for cooling a turbine blade with a cooling fluid via an internal flow passage formed in the turbine blade extending from an inlet to an outlet edge having a first passage section defining a first flow direction, a second passage section defining a second flow direction, a wall between the first and second passage section and a diverter, between the first and the second passage section. The wall in a region of the diverter forms a pier head which extends into the region of the first passage section and thereby reduces the flow cross section of the flow passage.

Claims

1. A cooling system for actively cooling a turbine blade with a cooling fluid comprising: the turbine blade having an inlet edge and an outlet edge; an internal flow passage formed in the turbine blade from an inlet to an outlet, which extends from the inlet edge to the outlet edge and comprises: a first passage section, which defines a first flow direction; a second passage section, which defines a second flow direction; a wall located between the first passage section and the second passage section; a curved diverter, between the first passage section and the second passage section, which is configured to transfer a fluid flow from the first flow direction into the second flow direction; and a pier head formed by the wall in a region of the diverter, which at least with a pier head section extends into a region of the first passage section that reduces a flow cross section of the internal flow passage, wherein the curved diverter, between the first passage section and the second passage section comprises an arcuate portion opposite the pier head, wherein the second passage narrows in the second flow direction from a widest portion in an area of the pier head.

2. The cooling system according to claim 1, wherein the internal flow passage further comprises: a third passage section; a second curved diverter arranged at an end of the second passage section, which opens into the third passage section; a second wall between the second passage section and third passage section; and a second pier head formed by the second wall, which extends at least with a pier head section into a region of the second passage section that reduces the flow cross section of the internal flow passage wherein the second passage has a narrowest portion in an area of the second pier head.

3. The cooling system according to claim 2, wherein an outer contour of the second pier head viewed in a flow direction extends as follows: commencing from a linearly extending wall of the second passage section with a curvature section, which curves in a direction of the third passage section, merging into a part circle-shaped arc section of opposite curvature, which in turn, at an outlet of the diverter, merges into a linearly extending wall of the third passage section, without the outer contour projecting into the third passage section.

4. The cooling system according to claim 3, wherein the turbine blade comprises an annular space between a lower blade contour and an upper blade contour, which defines a gas-conducting surface of the turbine blade.

5. The cooling system according to claim 4, wherein a center of the pier head is arranged in a region which is arranged offset relative to the annular space within the blade contour lower or the upper blade contour.

6. The cooling system according to claim 2, wherein the second curved diverter is configured to divert the flow direction by substantially 160°.

7. The cooling system according to claim 1, wherein the pier head viewed in cross section is formed at least in a face-end section one of circular arc-shaped, curved, or drop-shaped and extends in a direction of the first passage section.

8. The cooling system according to claim 1, wherein the pier head, viewed in cross section, is formed, at least in a face end section, from a plurality of linear and/or polynomial sections and extends in a direction of the first passage section.

9. The cooling system according to claim 1, wherein an outer contour of the pier head viewed in a flow direction extends as follows: commencing from a linearly extending wall of the first passage section with a curvature section, which curves in a direction of the first passage section, merging into a part circle-shaped arc section of opposite curvature, which in turn, at an outlet of the diverter, merges into a linearly extending wall of the second passage section, without the outer contour projecting into the second passage section.

10. The cooling system according to claim 1, wherein the internal flow passage further comprises: the inlet, which forms an opening for receiving the cooling fluid in the internal flow passage; and the outlet configured as a blowout, which forms an opening for letting the cooling fluid out of the internal flow passage.

11. The cooling system according to claim 1, wherein the turbine blade, in a region of the inlet edge, comprises a multiplicity of outlet openings configured to let the cooling fluid out of the internal flow passage, which are arranged spaced from one another.

12. The cooling system according to claim 1, wherein the turbine blade comprises a multiplicity of outlet openings configured to let the cooling fluid out of the internal flow passage, which are arranged spaced from one another.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Other advantageous further developments of the invention are characterized in the subclaims and are shown in more detail in the following by way of the figures together with the description of the preferred embodiment of the invention.

(2) It shows:

(3) FIG. 1 is a perspective view of a turbine blade with a flow passage located inside; and

(4) FIG. 2 is a sectional view through a mould for explaining the forming of a flow passage.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

(5) In the following, the invention is described by way of an exemplary embodiment making reference to FIG. 1 and FIG. 2.

(6) In FIG. 1, a perspective view of a turbine blade 2 with a flow passage 3 located inside, which is not shown in more detail in FIG. 1, is shown. The turbine blade 2 comprises a rounded inlet edge 4 and an outlet edge 5 and during the course from the inlet edge 4 to the outlet edge 5 is slightly curved. Furthermore, the turbine blade 2 has an upper blade contour 12 and a lower blade contour 13, by which the turbine blade 2 can be mounted in the turbine. The two blade contours 12, 13 each form a surface F substantially extending transversely to the turbine blade 2, which together with the turbine blade 2 forms the gas-conducting annular space 11. Furthermore, FIG. 1 shows multiple outlet openings 14 spaced from one another in the region of the inlet edge 4. Apart from this, multiple outlet openings 15 are formed on the turbine blade 2 which are located on the outlet edge 5.

(7) FIG. 2 shows a sectional view of a mould, by way of which the flow passage 3 is described. The flow passage 3 is formed with an inlet 25 and an outlet 26. The flow passage comprises a first passage section 6, which is followed by the diverter 9, which initially diverts the flow direction by approximately 90° and then by a further approximately 90° back into the approximately opposite direction in a second passage section 7, which is formed between the diverter 9 and a second diverter 16, and a third passage section 17, which adjoins the diverter 16, which in turn diverts the flow direction by approximately 160° in the approximately opposite direction. Apart from this, FIG. 2 shows the wall 8 and the pier head 10 formed thereon. Commencing from the linearly extending wall 8 of the first passage section 6, the pier head 10 extends with a curvature section 21, which curves in the direction of the passage section 6. The curvature section 21 merges into a part circle-shaped arc section 22 of opposite curvature which in turn merges into the linearly extending wall 8 of the second passage section 7 at the outlet of the diverter 9, however without the outer contour projecting into the second passage section 7.

(8) Furthermore, FIG. 2 shows the wall 18 between the second and third passage section 7, 17 and the pier head 19 formed thereon. Commencing from the linearly extending wall 18 of the second passage section 7, the pier head 19 extends with a curvature section 23, which curves in the direction of the passage section 7. The curvature section 23 merges into a part circle-like arc section 24 of opposite curvature, which in turn merges into the linearly extending wall 18 of the third passage section 17 at the outlet of the diverter 16 however without the outer contour projecting into the third passage section 17.

(9) The arrows in FIG. 2 schematically show the flow pattern in the flow passage 3 produced with the mould.

(10) In this embodiment, the invention is not restricted to the preferred exemplary embodiments stated above. A number of versions is also conceivable which make use of the shown solution even with embodiments of fundamentally different types.

(11) Thus, while there have shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.