Claims
- 1. A turbine vane segment for forming part of a nozzle stage of a turbine, comprising:
inner and outer walls spaced from one another; a turbine vane extending between said inner and outer walls and having leading and trailing edges, said vane including a plurality of discrete cavities between the leading and trailing edges and extending lengthwise of said vane for flowing a cooling medium through said vane; a plenum defined adjacent one of said inner and outer walls, at least one of said cavities of said vane being in flow communication with said plenum via an opening at a radial end of said vane to enable passage of cooling medium from said at least one cavity into said plenum; and a flow control structure for channeling cooling media flow to a fillet region defined at a transition between a wall of said vane and said one wall for cooling said fillet region.
- 2. A turbine vane segment as in claim 1, wherein said flow control structure is mounted to one of said vane and said one wall so as to define a gap with said fillet region.
- 3. A turbine vane segment as in claim 2, further comprising first and second exit flow slots defined along longitudinal side edges of said flow control structure to define a flow path for coolant flow exiting said cavity.
- 4. A turbine vane segment as in claim 3, further comprising first and second shields projecting radially from a base of said flow control structure, along said exit flow slots for isolating cooling exit flow.
- 5. A turbine vane segment as in claim 1, wherein said flow control structure comprises a base and a main body, said main body projecting into said opening of said cavity.
- 6. A turbine vane segment as in claim 5, wherein main body is configured to define a crest generally at a transverse mid portion of said base and to define slopped walls from said crest toward longitudinal side edges of said base, thereby to split flow exiting said cavity into flows along respective fillet regions on each side of said vane.
- 7. A turbine vane segment as in claim 6, wherein a radial height of said crest of said main body varies along a length of said main body.
- 8. A turbine vane segment as in claim 7, wherein said main body includes a first portion having a first radial height and extending from a leading edge thereof along a first portion of the length thereof and a second portion having a second, lesser radial height extending from adjacent a trailing end of said first portion along a second portion of the length of the main body.
- 9. A turbine vane segment as in claim 8, further comprising a radial height transition portion interconnecting said first and second portions of said main body.
- 10. A turbine vane segment as in claim 6, further comprising first and second exit flow slots defined along said longitudinal side edges of said base of said flow control structure to define a flow path for coolant flow exiting said cavity.
- 11. A turbine vane segment as in claim 10, further comprising first and second shields projecting radially from said base along said exit flow slots.
- 12. A turbine vane segment as in claim 11, further comprising an impingement plate mounted to said one wall in spaced relation to an inner surface thereof, said impingement plate having holes for passage of the cooling medium for impingement cooling of said one wall, whereby said flow shields isolate exiting coolant flow from said impingement plate holes.
- 13. A turbine vane segment as in claim 5, wherein said base of said flow control structure is mounted to said inner wall.
- 14. A turbine vane segment as in claim 5, wherein said base and said main body are separately formed and are mechanically secured together to define said flow control structure.
- 15. A method of cooling the fillet region of a nozzle comprising:
providing a nozzle vane segment including inner and outer walls spaced from one another; a turbine vane extending between said inner and outer walls and having leading and trailing edges, said vane including a plurality of discrete cavities between the leading and trailing edges and extending lengthwise of said vane for flowing a cooling medium through said vane; and a plenum defined adjacent one of said inner and outer walls, at least one of said cavities of said vane being in flow communication with said plenum via an opening at a radial end of said vane to enable passage of cooling medium from said at least one cavity into said plenum; disposing a flow control structure at said opening; flowing coolant medium through said cavity; channeling said flowing coolant medium at said outlet with said flow control structure to a fillet region defined at a transition between a wall of said vane and said one wall for cooling said fillet region.
- 16. A method as in claim 15, wherein said step of disposing a flow control structure at said opening comprises mounting said flow control structure to one of said vane and said one wall so as to define a coolant flow gap with said fillet region.
- 17. A method as in claim 16, wherein said flow control structure comprises a base and a main body, said base is mounted to said one wall and said main body is disposed to project into said opening of said cavity.
- 18. A method as in claim 17, wherein said main body is configured to define a crest generally at a transverse mid portion of said base and to define slopped walls from said crest toward longitudinal side edges of said base, whereby coolant flow exiting said cavity is split into flows along respective fillet regions on each side of said vane.
- 19. A flow control structure for channeling cooling media flow to a fillet region defined at a transition between a wall of a nozzle vane and a wall of a nozzle segment, for cooling the fillet region, comprising:
a base; and a main body, said main body being configured to define a crest generally at a transverse mid portion of said base and to define sloped walls from said crest toward longitudinal side edges of said base, thereby to define a gap with the fillet region to channel coolant flow along the fillet region.
- 20. A flow control structure as in claim 19, wherein a height of said crest of said main body varies along a length of said main body.
- 21. A flow control structure as in claim 20, wherein said main body includes a first portion having a first height and extending from a leading edge thereof along a first portion of the length thereof and a second portion having a second, lesser height extending from adjacent a trailing end of said first portion along a second portion of the length of the main body.
- 22. A flow control structure as in claim 21, further comprising a height transition portion interconnecting said first and second portions of said main body.
- 23. A flow control structure as in claim 19, further comprising first and second exit flow slots defined along said longitudinal side edges of said base to define a flow paths for spent coolant flow.
- 24. A flow control structure as in claim 23, further comprising first and second longitudinally extending shields projecting from a bottom face of said base along said exit flow slots.
- 25. A flow control structure as in claim 23, wherein said base and said main body are separately formed and are mechanically secured together.
FEDERAL RESEARCH STATEMENT
[0001] [Federal Research Statement Paragraph] This invention was made with Government support under Contract No. DE-FC21-95MC31176 awarded by the Department of Energy. The Government has certain rights in this invention.