Closed or open air cooling circuits for nozzle segments with wheelspace purge

• US 5,591,002 A
• Filed: 08/01/1995
• Issued: 01/07/1997
• Est. Priority Date: 08/23/1994
• Status: Expired due to Fees

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Walker, Alan, Cunha, Francisco J.
• Primary Examiner(s): Look, Edward K.
• Assistant Examiner(s): VERDIER, CHRISTOPHER M
• Application Number:
  US08/509,917
• Time in Patent Office: 525 Days
• Field of Search: 415/115, 415/116, 415/914, 416/96 R, 416/96 A, 416/97 R, 416/97 A
• 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
• CPC Class Codes: F05D 2260/2322 steam

Abstract

The nozzle segment includes a vane having a plurality of axially spaced cavities for transmission of a cooling medium. In a closed circuit cooling system, air is transmitted radially inwardly and outwardly through inserts in leading and intermediate cavities, respectively, for flow through holes for impingement cooling of the adjoining vane surfaces. Radial inlet flow of cooling medium to an aft cavity likewise flows through an insert for impingement cooling of the aft cavity walls. The cooling medium flows from the aft cavity into a trailing edge cavity for impingement cooling of the trailing edge. The spent cooling flow passes through a channel in the diaphragm into the wheelspace. In the open air circuit, the spent impingement flow in the leading and intermediate cavities passes through openings in the vane wall for thin film cooling of the vane. An insert is received in the trailing edge cavity for impingement cooling of the trailing edge walls and flow towards the trailing edge on opposite sides of a tongue for turbulent flow through a multiplicity of openings through the trailing edge into the hot gas stream.

Claims

1. An open circuit air-cooled stator 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 discrete leading edge, trailing edge and intermediate cavities between the leading and trailing edges and extending radially of said vane, first and second air inlets for supplying cooling air to said leading edge and trailing edge cavities, respectively;

an insert in said leading edge cavity for receiving cooling air from said first air inlet and having impingement openings for directing the cooling air against interior wall surfaces of said leading edge cavity for impingement cooling of the vane about said leading edge cavity;

an insert in said trailing edge cavity for receiving cooling air from said second air inlet and having impingement openings for directing the cooling air against interior wall surfaces of said vane for impingement cooling of said vane about said trailing edge cavity;

said trailing edge cavity having openings for delivery of cooling air through the trailing edge of said vane; and

an insert in said intermediate cavity having an air inlet adjacent said outer wall and an outlet adjacent said inner wall, said intermediate insert having an internal passage dedicated for supplying cooling air radially inwardly from said inlet to said outlet and into a wheelspace between adjacent turbine stages.

2. A stator vane segment according to claim 1 including a plurality of generally radially extending, axially spaced ribs formed along the interior wall surfaces of said vane opposite said trailing edge insert for creating a turbulent flow of cooling air from said trailing edge insert along said interior wall surfaces toward said openings.

3. A stator vane segment according to claim 2 including a plurality of protuberances along said interior wall surfaces between said ribs affording enhanced turbulated air flow.

4. A closed circuit air-cooled stator 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 discrete leading edge, trailing edge and intermediate cavities between the leading and trailing edges and extending radially of said vane, first and second air inlets for supplying cooling air to said leading edge and trailing edge cavities, respectively;

an insert in said leading edge cavity for receiving cooling air from said first air inlet and having impingement openings for directing the cooling air against interior wall surfaces of said leading edge cavity for impingement cooling of the vane about said leading edge cavity;

an insert in said intermediate cavity for receiving cooling air and having impingement openings for directing the cooling air against interior wall surfaces of said intermediate cavity for impingement cooling of said vane about said intermediate cavity;

said trailing edge cavity through said vane lying in communication with said second inlet for receiving cooling air therefrom and having an outlet at a radially inner end thereof, said outlet including a passage for directing spent cooling air into a wheelspace between adjacent turbine stages; and

said inner wall including a flow passage interconnecting a radially inner end of said leading edge cavity and an inner end of said intermediate cavity whereby air in said leading edge and intermediate cavities flows in generally opposite radial directions.

5. A closed circuit air-cooled stator 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 discrete leading edge, trailing edge and intermediate cavities between the leading and trailing edges and extending radially of said vane, first and second air inlets for supplying cooling air to said leading edge and trailing edge cavities, respectively;

an insert in said leading edge cavity for receiving cooling air from said first air inlet and having impingement openings for directing the cooling air against interior wall surfaces of said leading edge cavity for impingement cooling of the vane about said leading edge cavity;

an insert in said intermediate cavity for receiving cooling air and having impingement openings for directing the cooling air against interior wall surfaces of said intermediate cavity for impingement cooling of said vane about said intermediate cavity;

said trailing edge cavity through said vane lying in communication with said second inlet for receiving cooling air therefrom and having an outlet at a radially inner end thereof, said outlet including a passage for directing spent cooling air into a wheelspace between adjacent turbine stages; and

a discrete aft cavity between said intermediate cavity and said trailing edge cavity, an insert in said aft cavity for receiving cooling air and having impingement openings for directing the cooling air adjacent interior wall surfaces of said vane for impingement cooling of said vane about said aft cavity, a plurality of ribs projecting inwardly of said interior wall surfaces of said vane in said aft cavity at spaced locations therealong to define flow chambers between said interior wall surface and said insert in said aft cavity, a radially extending rib between said aft cavity and said trailing edge cavity including a plurality of openings in communication with said flow chambers for flowing air from said aft cavity into said trailing edge cavity.

6. A closed circuit air-cooled stator 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 discrete leading edge, trailing edge and intermediate cavities between the leading and trailing edges and extending radially of said vane, first and second air inlets for supplying cooling air to said leading edge and trailing edge cavities, respectively;

an insert in said leading edge cavity for receiving cooling air from said first air inlet and having impingement openings for directing the cooling air against interior wall surfaces of said leading edge cavity for impingement cooling of the vane about said leading edge cavity;

an insert in said intermediate cavity for receiving cooling air and having impingement openings for directing the cooling air against interior wall surfaces of said intermediate cavity for impingement cooling of said vane about said intermediate cavity;

said trailing edge cavity through said vane lying in communication with said second inlet for receiving cooling air therefrom and having an outlet at a radially inner end thereof, said outlet including a passage for directing spent cooling air into a wheelspace between adjacent turbine stages; and

a discrete aft cavity between said intermediate cavity and said trailing edge cavity, an insert in said aft cavity for receiving cooling air and having impingement openings for directing the cooling air against interior wall surfaces of said vane adjacent said aft cavity for impingement cooling of said vane, a plurality of ribs projecting inwardly of said interior wall surfaces of each said leading edge cavity, said intermediate cavity and said aft cavity at spaced locations therealong to define flow chambers between said interior wall surfaces and said inserts, at least two of said inserts having at least one radially extending flow channel each in communication with said flow chambers formed by respective inserts for directing spent cooling air from the respective cavity.

7. A closed circuit air-cooled stator 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 discrete leading edge, trailing edge and intermediate cavities between the leading and trailing edges and extending radially of said vane, first and second air inlets for supplying cooling air to said leading edge and trailing edge cavities, respectively;

an insert in said leading edge cavity for receiving cooling air from said first air inlet and having impingement openings for directing the cooling air against interior wall surfaces of said leading edge cavity for impingement cooling of the vane about said leading edge cavity;

an insert in said intermediate cavity for receiving cooling air and having impingement openings for directing the cooling air against interior wall surfaces of said intermediate cavity for impingement cooling of said vane about said intermediate cavity;

openings through side walls of said vane in communication with said leading edge cavity and said intermediate cavity, respectively, for receiving spent impingement cooling air therefrom and directing the spent impingement cooling air externally of the vane for thin film cooling thereof;

said trailing edge cavity through said vane lying in communication with said second inlet for receiving cooling air therefrom; and

an insert in said trailing edge cavity for receiving cooling air and having impingement openings for directing cooling air against interior wall surfaces of said trailing edge cavity for impingement cooling of said vane about said trailing edge cavity, said trailing edge cavity having trailing edge openings for delivery of cooling air through the trailing edge of the vane.

8. A closed circuit air-cooled stator 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 discrete leading edge, intermediate, aft and trailing edge cavities between the leading and trailing edges and extending radially of said vane, first and second air inlets for supplying cooling air to said leading edge and aft cavities, respectively;

an insert in said leading edge cavity for receiving cooling air from said first air inlet and having impingement openings for directing the cooling air against interior wall surfaces of said leading edge cavity for impingement cooling of the vane about said leading edge cavity;

an insert in said intermediate cavity for receiving cooling air and having impingement openings for directing the cooling air against interior wall surfaces of said intermediate cavity for impingement cooling of said vane about said intermediate cavity;

said inner wall including a flow passage interconnecting a radially inner end of said leading edge cavity and an inner end of said intermediate cavity whereby air in said leading edge and intermediate cavities flows in a closed circuit within said vane in generally opposite radial directions;

said aft cavity through said vane lying in communication with said second inlet for receiving cooling air therefrom; and

a plurality of openings spaced radially one from another along said vane providing communication between said aft cavity and said trailing edge cavity for flowing cooling air from said aft cavity into said trailing edge cavity, said trailing edge cavity having an outlet for the cooling air whereby the cooling air flows from said inlet through said aft and trailing edge cavities in a closed circuit with said vane.

9. An open circuit air-cooled stator 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 discrete leading edge, trailing edge and intermediate cavities between the leading and trailing edges and extending radially of said vane, first and second air inlets for supplying cooling air to said leading edge and trailing edge cavities, respectively;

an insert in said leading edge cavity for receiving cooling air from said first air inlet and having impingement openings for directing the cooling air against interior wall surfaces of said leading edge cavity for impingement cooling of the vane about said leading edge cavity;

an insert in said trailing edge cavity for receiving cooling air from said second air inlet and having impingement openings for directing the cooling air against interior wall surfaces of said vane for impingement cooling of said vane about said trailing edge;

said trailing edge cavity having openings for delivery of cooling air through the trailing edge of said vane;

an insert in said intermediate cavity having an air inlet adjacent said outer wall and an outlet adjacent said inner wall, said intermediate insert having an internal passage dedicated for supplying cooling air radially inwardly from said inlet to said outlet and into a wheelspace between adjacent turbine stages; and

a tongue in said trailing edge cavity between said trailing edge insert and said trailing edge, said tongue having side wall surfaces spaced from interior wall surfaces of said vane opposite said side wall surfaces defining flow paths for directing cooling air along the interior wall surfaces of the vane toward said trailing edge openings.

10. An open circuit air-cooled stator 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 discrete leading edge, trailing edge and intermediate cavities between the leading and trailing edges and extending radially of said vane, first and second air inlets for supplying cooling air to said leading edge and trailing edge cavities, respectively;

an insert in said leading edge cavity for receiving cooling air from said first air inlet and having impingement openings for directing the cooling air against interior wall surfaces of said leading edge cavity for impingement cooling of the vane about said leading edge cavity;

an insert in said trailing edge cavity for receiving cooling air from said second air inlet and having impingement openings for directing the cooling air against interior wall surfaces of said vane for impingement cooling of said vane about said trailing edge cavity;

said trailing edge cavity having openings for delivery of cooling air through the trailing edge of said vane;

an insert in said intermediate cavity having an air inlet adjacent said outer wall and an outlet adjacent said inner wall, said intermediate insert having an internal passage dedicated for supplying cooling air radially inwardly from said inlet to said outlet and into a wheelspace between adjacent turbine stages; and

a channel between said intermediate insert and interior wall surfaces of said vane opposite said insert, an inlet to said channel adjacent said outer wall for supplying air to said channel for radially inwardly directed flow, and openings in said interior wall surfaces for flowing cooling air from said channel along exterior wall surfaces of said vane for thin film cooling thereof.

11. A stator vane segment according to claim 10 including a plurality of generally radially directed, axially spaced ribs formed along the interior wall surfaces of said vane opposite said tongue for creating a turbulent flow of cooling air from said trailing edge insert along said interior wall surfaces opposite said tongue toward said openings.

12. A stator vane segment according to claim 11 including a plurality of protuberances along said interior wall surfaces between said ribs affording enhanced turbulated air flow.