Turbine stator vane segments having combined air and steam cooling circuits

• US 5,743,708 A
• Filed: 07/02/1996
• Issued: 04/28/1998
• Est. Priority Date: 08/23/1994
• Status: Expired due to Term

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Chopra, Sanjay, Cunha, Francisco J., DeAngelis, David A., Correia, Victor H. S., Predmore, Daniel R., Brown, Theresa A.
• Primary Examiner(s): VERDIER, CHRISTOPHER M
• Application Number:
  US08/674,476
• Time in Patent Office: 665 Days
• Field of Search: 415/114, 415/115, 415/116, 415/189, 415/190, 415/191, 415/209.2, 415/209.3, 415/915, 416/96 R, 416/96 A, 416/97 R, 60/39.53, 60/39.58, 60/39.59
• US Class Current: 415/115
• CPC Class Codes: F01D 11/005 Sealing means between non relatively rotating elements
• CPC Class Codes: F01D 5/187 Convection cooling
• CPC Class Codes: F01D 5/188 with an insert in the blade cavity to guide the cooling fluid, e.g. forming a separation wall
• CPC Class Codes: F01D 5/189 the insert having a tubular cross-section, e.g. airfoil shape
• CPC Class Codes: F05D 2240/10 Stators
• CPC Class Codes: F05D 2240/81 Cooled platforms
• CPC Class Codes: F05D 2260/201 by impingement of a fluid
• CPC Class Codes: F05D 2260/2212 by creating turbulence vortex generators, turbulators or the like for mixing F05D2240/127
• CPC Class Codes: F05D 2260/2322 steam
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

Turbine stator vane segments have inner and outer walls with vanes extending therebetween. The inner and outer walls are compartmentalized and have impingement plates. Steam flowing into the outer wall passes through the impingement plate for impingement cooling of the outer wall surface. The spent impingement steam flows into cavities of the vane having inserts for impingement cooling the walls of the vane. The steam passes into the inner wall and through the impingement plate for impingement cooling of the inner wall surface and for return through return cavities having inserts for impingement cooling of the vane surfaces. The trailing edge is air-cooled.

Claims

1. A turbine having an axis, comprising:

inner and outer shells spaced one from the other and about said axis;

a plurality of stator vane segments in a circumferential array about said axis and forming part of a turbine stage, each said segment including inner and outer walls spaced from one another;

a stator vane extending between said inner and outer walls and having forward leading and aft 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; and

a forward hook connected to said vane and spaced radially outwardly of said outer wall for supporting said stator vane from said inner turbine shell, said inner and outer walls, said vane and said hook being formed of an integral casting.

2. A stator vane segment for forming part of a stage of a turbine and connection with an inner shell of the turbine, comprising:

inner and outer walls spaced from one another;

a stator vane extending between said inner and outer walls and having forward leading and aft 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;

a forward hook connected to said vane and spaced radially outwardly of said outer wall for supporting said stator vane from the inner turbine shell, said inner and outer walls, said vane and said hook being formed of an integral casting; and

a closed-circuit cooling system for said stator vane comprising at least one cavity of said vane having a plurality of ribs projecting inwardly of an inner wall surface of said vane at spaced locations along the length of said vane, an insert sleeve within said one cavity and engaging said ribs defining discrete gaps between said insert sleeve and the inner wall of said vane at spaced locations along said vane, said insert having an inlet adjacent one of said inner and outer walls for flowing the cooling medium into said insert sleeve, said insert sleeve having a plurality of openings therethrough for flowing the cooling medium through said sleeve openings into said gaps for impingement against an inner wall surface of said vane, said insert and said inner wall surface of said vane defining a channel therebetween along a side wall of said vane in communication with said gaps for receiving the cooling medium flowing into said gaps and directing the cooling medium in a generally radial direction to an outlet adjacent another of said inner and outer walls.

3. A stator vane segment according to claim 2 wherein said ribs terminate short of fully encompassing said one cavity, terminal ends of said ribs defining ends of said gaps opening into said channel.

4. A turbine vane segment, comprising:

inner and outer walls spaced from one another;

a 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 in a closed circuit through said vane;

at least one cavity of said vane having a plurality of ribs projecting inwardly of an inner wall surface of said vane at spaced locations along the length of said vane, an insert sleeve within said one cavity and engaging said ribs defining discrete gaps between said insert sleeve and the inner wall of said vane at spaced locations along said vane, an inlet to said insert sleeve adjacent one of said inner and outer walls for flowing the cooling medium into said insert sleeve, said insert sleeve having a plurality of openings therethrough for flowing the cooling medium through said sleeve openings into said gaps for impingement against an inner wall surface of said vane, said insert and said inner wall surface of said vane defining a channel therebetween and along a side wall of said vane in communication with said gaps for receiving the cooling medium flowing into said gaps and directing the cooling medium in a radial direction to an outlet adjacent another of said inner and outer walls.

5. A turbine vane segment, comprising:

inner and outer walls spaced from one another;

a 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 between said inner and outer walls, a closed-circuit cooling system through said vane including at least two of said cavities;

an insert sleeve within each of said at least two cavities and spaced inwardly of inner wall surfaces of said vane defining a volume therebetween, an inlet to each of said insert sleeves for flowing a cooling medium into said insert sleeves, each said insert sleeve having openings therethrough for flowing the cooling medium through said openings into said volumes for impingement against the inner wall surfaces of said vane, a first of said two cavities having an outlet in communication with the inlet to a second of said two cavities, said outlet and the inlet to said second of said two cavities lying adjacent said inner wall, an outlet for said second cavity passing through said outer wall, whereby the cooling medium flows through said first cavity in one direction through said second cavity in a generally opposite direction, and through said outer wall; and

a third cavity of said plurality of cavities comprising a trailing edge cavity having a plurality of openings through a wall of said vane for flowing cooling air from said trailing edge cavity through said third cavity openings into a region external of said vane.

6. A turbine vane segment according to claim 5 wherein at least certain of said plurality of openings in communication with said trailing edge cavity are spaced one from the other along one of the opposite sides of said vane to provide air film cooling of said vane along said one side thereof.

7. A turbine vane segment according to claim 6 wherein said third cavity openings include openings extending through the trailing edge of said vane.

8. A turbine vane segment according to claim 5 wherein said plurality of openings in communication with said trailing edge cavity are spaced one from the other along each of the opposite sides of said vane.

9. A turbine vane segment according to claim 8 including a trough along the outer surface of said vane on said opposite sides thereof with said third cavity openings terminating in said trough.

10. A turbine vane segment according to claim 5 wherein said inlet to said first cavity is located adjacent said outer wall.

11. A turbine vane segment according to claim 10 wherein said first cavity is located along said leading edge of said vane and said second cavity is located between said first and third cavities.

12. A turbine vane segment according to claim 5 wherein at least one cavity of said two cavities has a plurality of ribs projecting inwardly of an inner wall surface portion of said vane at spaced locations along the length of said vane, said insert sleeve within said one cavity engaging said ribs defining discrete gaps in said volumes between said insert sleeve and the inner wall surface portion of said vane at spaced locations along the length of said vane, said plurality of openings through said insert sleeve within said one cavity enabling flow of the cooling medium through said sleeve openings into said gaps for impingement against said inner wall surface portion of said vane, said insert within said one cavity and said inner wall surface portion of said vane defining a channel therebetween and along a side wall of said vane in communication with said gaps for receiving the cooling medium flowing into said gaps.

13. A turbine vane segment according to claim 5 wherein said inner wall includes a plenum in communication with said outlet of said first cavity and said inlet of said second cavity, an impingement plate in said plenum for flowing the cooling medium received from said first cavity outlet through openings in said impingement plate for impingement cooling of an inner wall surface portion having an opposite side thereof exposed to flow of hot gases along a hot gas path of the turbine vane segment, said second cavity inlet lying in communication with the cooling medium passing through the impingement plate openings for flowing spent impingement cooling medium through said second cavity.