Crossover cooled airfoil trailing edge

Patent metadata

Field	Value
Publication number	US-9388699-B2
Application number	US-201313961194-A
Country	US
Kind code	B2
Filing date	Aug 7, 2013
Priority date	Aug 7, 2013
Publication date	Jul 12, 2016
Grant date	Jul 12, 2016

Abstract

A cooling circuit for a turbine bucket having an airfoil portion includes a trailing edge cooling circuit portion provided with a first radially outwardly directed inlet passage intermediate leading and trailing edges of the airfoil portion of the bucket, extending from a platform portion of the bucket to a location adjacent a radially outer tip of the bucket, and connecting to a second radially inwardly directed passage extending from a location adjacent the radially outer tip to a location adjacent the platform portion. The second radially inwardly directed passage connects to a third trailing edge region passage, and a plurality of crossover passages connect a radially outer half of the second radially inwardly directed passage to a radially outer half of the third trailing edge region passage.

First claim

What is claimed is:

1. A cooling circuit for a turbine bucket having an airfoil portion comprising: a trailing edge cooling circuit portion including a first radially-oriented passage intermediate leading and trailing edges of said airfoil portion of said bucket, extending from a platform portion of the bucket to a location adjacent a radially outer tip of the bucket for radial outward flow of a cooling medium, and connecting to a second radially-oriented passage extending from a location adjacent the radially outer tip to a location adjacent the platform portion for radial inward flow of the cooling medium, the second radially-oriented passage connecting to a third radially-oriented trailing edge region passage for radial outward flow of the cooling medium; wherein a plurality of crossover passages connect a radially outer half of the second radially-oriented passage to a radially outer half of the third radially-oriented, trailing edge region passage.

2. The cooling circuit for a turbine bucket of claim 1 wherein the plurality of crossover passages connect a radially outer quarter of the second radially-oriented passage to a radially outer quarter of the radially-oriented trailing edge region passage.

3. The cooling circuit for a turbine bucket of claim 1 wherein said plurality of crossover passages have round or oval cross sectional shapes.

4. The cooling circuit for a turbine bucket of claim 1 wherein said plurality of crossover passages is uniformly or non-uniformly spaced from each other in a radial direction.

5. The cooling circuit for a turbine bucket of claim 1 wherein said plurality of crossover passages comprise between two and six passages.

6. The cooling circuit for a turbine bucket of claim 1 wherein said plurality of crossover passages are comprised of tubes.

7. The cooling circuit for a turbine bucket of claim 1 further comprising a discrete forward cooling circuit isolated from said trailing edge circuit but supplied with cooling air from a common source.

8. A gas turbine system comprising a compressor, one or more combustors, at least one turbine stage and a generator, a rotor extending axially through the compressor and the at least one turbine stage; at least one rotor wheel fixed to said rotor and mounting a plurality of buckets extending about a periphery of said at least one rotor wheel, each of said plurality of buckets provided with a trailing edge cooling circuit including a first radially-oriented passage intermediate leading and trailing edges of an airfoil portion of the bucket, extending from a platform portion of the bucket to a location adjacent a radially outer tip of the bucket, and connecting to a second radially-oriented passage extending from the location adjacent the radially outer tip to a location adjacent the platform portion, the second radially-oriented passage connecting to a radially-oriented trailing edge region cavity; wherein a plurality of crossover passages connect only a radially outer half of the second radially-oriented passage to a radially outer half of the radially-oriented trailing edge region cavity.

9. The gas turbine system of claim 8 wherein the plurality of crossover passages connect only a radially outer quarter of the second radially-oriented passage to a radially outer quarter of the radially-oriented trailing edge region cavity.

10. The gas turbine system of claim 8 wherein said plurality of crossover passages have round or oval cross sectional shapes.

11. The gas turbine system of claim 8 wherein said plurality of crossover passages are uniformly or non-uniformly spaced from each other in a radial direction.

12. The gas turbine system of claim 8 wherein said plurality of crossover passages comprise between two and six passages.

13. The gas turbine system of claim 8 wherein said plurality of crossover passages are comprised of tubes.

14. The gas turbine system of claim 8 further comprising a discrete leading edge circuit isolated from said trailing edge circuit but supplied with cooling air from a common source.

15. The gas turbine system of claim 8 wherein plural film cooling holes extend from said trailing edge region cavity to said trailing edge.

16. A method of cooling a targeted area within a radially outer portion of an airfoil portion of a bucket comprising:
a. supplying cooling air to an internal, serpentine cooling circuit in an aft region of the bucket airfoil providing at least two radially outward flow paths and a radially inward flow path therebetween, and
b. diverting at least some cooling air at a radially outward end of the radially inward flow path directly into a radially outer end of the radially outward flow path proximate the trailing edge of the airfoil to thereby preferentially cool a targeted area in a radially outer area proximate the trailing edge.

17. The method of claim 16 wherein step b. is achieved by providing a plurality of crossover passages connecting a radially outer quarter of the radially inward flow path to a radially outer quarter of the radially outward flow path.

18. The method of claim 17 wherein between 2 and 6 crossover passages are provided, said crossover passages, each formed with round or oval cross-sectional shapes.

19. The method of claim 16 wherein a discrete second cooling circuit is provided in a forward region of the bucket airfoil.

20. The method of claim 16 wherein the bucket is mounted on a first or second stage turbine rotor wheel.

Assignees

• Dong Zhirui
• Zhang Xiuhang James
• Myers Melbourne James
• Sampayo Camilo Andres
• Gen Electric

Inventors

• Dong Zhirui
• Zhang Xiuhang James
• Myers Melbourne James
• Sampayo Camilo Andres

Classifications

• F01D5/147 Primary

  Construction, i.e. structural features, e.g. of weight-saving hollow blades (F01D5/148, F01D5/16 and F01D5/20 take precedence; blade shape F01D5/141; blades with cooling or heating channels or cavities F01D5/18; heating, heat-insulating or cooling means on blades F01D5/18) · CPC title

• F01D5/186

  Film cooling (F01D5/187 takes precedence) · CPC title

• F01D5/187 Primary

  Convection cooling · CPC title