Turbine blade cooling system with bifurcated mid-chord cooling chamber

• US 7,413,407 B2
• Filed: 03/29/2005
• Issued: 08/19/2008
• Est. Priority Date: 03/29/2005
• Status: Expired due to Fees

• Current Assignee: Siemens Energy Incorporated (Siemens AG)
• Original Assignee: Siemens Power Generation, Inc.
• Inventors: Liang, George
• Primary Examiner(s): EDGAR, RICHARD A
• Application Number:
  US11/093,161
• Publication Number:
  US 20060222495A1
• Time in Patent Office: 1,239 Days
• Field of Search: 416/97.R
• US Class Current: 416/97.00R
• CPC Class Codes: F01D 5/186 Film cooling F01D5/187 takes precedence
• CPC Class Codes: F01D 5/187 Convection cooling
• CPC Class Codes: F05D 2250/185 serpentine-like
• CPC Class Codes: F05D 2260/202 by film cooling
• CPC Class Codes: F05D 2260/221 Improvement of heat transfer
• CPC Class Codes: F05D 2260/22141 using fins or ribs

Abstract

A cooling system for a turbine blade of a turbine engine having a bifurcated mid-chord cooling chamber for reducing the temperature of the blade. The bifurcated mid-chord cooling chamber may be formed from a pressure side serpentine cooling channel and a suction side serpentine cooling channel. The pressure side and suction side serpentine cooling channels may flow counter to each other, thereby yielding a more uniform temperature distribution than conventional serpentine cooling channels.

Claims

1. A turbine blade, comprising:

a generally elongated blade having a leading edge, a trailing edge, a tip section at a first end, a root coupled to the blade at an end generally opposite the first end for supporting the blade and for coupling the blade to a disc, and at least one cavity forming a cooling system in the blade;

the cooling system, comprising;

at least one leading edge cooling channel positioned in close proximity to the leading edge of the generally elongated blade;

at least one trailing edge cooling channel positioned in close proximity to the trailing edge of the generally elongated blade;

a bifurcated mid-chord cooling chamber positioned between the at least one leading edge cooling channel and the at least one trailing edge cooling channel, wherein the mid-chord cooling channel includes a pressure side serpentine cooling channel in contact with a pressure sidewall of the generally elongated blade and a suction side serpentine cooling channel in contact with a suction sidewall of the generally elongated blade and separated from the at least one pressure side serpentine cooling channel by a mid-chord rib;

an aperture in the mid-chord rib providing a cooling fluid passageway between the pressure and suction side serpentine cooling channels,

wherein the aperture is positioned in the mid-chord rib to exhaust cooling fluids from the pressure side serpentine cooling channel and to supply cooling fluids to the suction side serpentine cooling channel; and

wherein the suction side serpentine cooling channel is positioned relative to the pressure side serpentine cooling channel such that a cooling fluid flow direction through the suction side serpentine cooling channel is generally opposite to the cooling fluid flow in adjacent portions of the pressure side serpentine cooling channel, thereby forming cooling fluid counterflow between the pressure side and suction side serpentine cooling channels.

2. The turbine blade of claim 1, wherein the aperture in the mid-chord rib is positioned proximate to an end of the pressure side serpentine cooling channel and a beginning of the suction side serpentine cooling channel of the turbine blade.

3. The turbine blade of claim 1, wherein the pressure side serpentine cooling channel in contact with the pressure sidewall of the generally elongated blade is a triple pass serpentine cooling channel.

4. The turbine blade of claim 1, wherein the suction side serpentine cooling channel in contact with the suction sidewall of the generally elongated blade is a quadruple pass serpentine cooling channel.

5. The turbine blade of claim 1, further comprising a plurality of trip strips in the suction side serpentine cooling channel and a plurality of trip strips in the pressure side serpentine cooling channel.

6. The turbine blade of claim 1, further comprising at least one orifice in a rib positioned between the at least one leading edge cooling channel and the pressure side serpentine cooling channel.

7. The turbine blade of claim 1, wherein the at least one trailing edge cooling channel is formed from at least one vortex chamber for creating vortices from the cooling fluids.

8. The turbine blade of claim 7, wherein the at least one vortex chamber may be formed from three vortex chambers positioned in series and generally parallel to the trailing edge of the generally elongated blade.

9. The turbine blade of claim 8, wherein orifices in a first rib extending between adjacent vortex chambers are offset along a longitudinal axis of the elongated blade relative to orifices in another rib extending between vortex chambers.

10. The turbine blade of claim 1, wherein the at least one trailing edge cooling channel includes a plurality of impingement orifices in a rib separating the mid-chord cooling chamber and the at least one trailing edge cooling channel.

11. The turbine blade of claim 1, further comprising a plurality of exhaust orifices in the trailing edge for exhausting cooling fluids from the at least one trailing edge cooling channel.

12. A turbine blade, comprising:

a generally elongated blade having a leading edge, a trailing edge, a tip section at a first end, a root coupled to the blade at an end generally opposite the first end for supporting the blade and for coupling the blade to a disc, and at least one cavity forming a cooling system in the blade;

the cooling system, comprising;

at least one leading edge cooling channel positioned in close proximity to the leading edge of the generally elongated blade;

at least one trailing edge cooling channel positioned in close proximity to the trailing edge of the generally elongated blade;

a bifurcated mid-chord cooling chamber positioned between the at least one leading edge cooling channel and the at least one trailing edge cooling channel, wherein the mid-chord cooling channel includes a pressure side serpentine cooling channel in contact with a pressure sidewall of the generally elongated blade and a suction side serpentine cooling channel in contact with a suction sidewall of the generally elongated blade and separated from the at least one pressure side serpentine cooling channel by a mid-chord rib;

an aperture in the mid-chord rib providing a cooling fluid passageway between the pressure and suction side serpentine cooling channels,

wherein the aperture is positioned in the mid-chord rib to exhaust cooling fluids from the pressure side serpentine cooling channel and to supply cooling fluids to the suction side serpentine cooling channel;

at least one orifice in a rib positioned between the at least one leading edge cooling channel and the pressure side serpentine cooling channel; and

wherein the at least one orifice comprises a plurality of impingement orifices adapted to allow cooling fluids to pass from the pressure side serpentine cooling channel to the at least one leading edge cooling channel and impinge on an inner surface of the wall forming the leading edge.

13. A turbine blade, comprising:

a generally elongated blade having a leading edge, a trailing edge, a tip section at a first end, a root coupled to the blade at an end generally opposite the first end for supporting the blade and for coupling the blade to a disc, and at least one cavity forming a cooling system in the blade;

the cooling system, comprising;

at least one leading edge cooling channel positioned in close proximity to the leading edge of the generally elongated blade;

at least one trailing edge cooling channel positioned in close proximity to the trailing edge of the generally elongated blade;

a bifurcated mid-chord cooling chamber positioned between the at least one leading edge cooling channel and the at least one trailing edge cooling channel, wherein the mid-chord cooling channel includes a pressure side serpentine cooling channel in contact with a pressure sidewall of the generally elongated blade and a suction side serpentine cooling channel in contact with a suction sidewall of the generally elongated blade and separated from the at least one pressure side serpentine cooling channel by a mid-chord rib;

an aperture in the mid-chord rib positioned proximate to an end of the pressure side serpentine cooling channel and a beginning of the suction side serpentine cooling channel of the turbine blade;

wherein the aperture provides a cooling fluid passageway between the pressure and suction side serpentine cooling channels to exhaust cooling fluids from the pressure side serpentine cooling channel and to supply cooling fluids to the suction side serpentine cooling channel; and

wherein the suction side serpentine cooling channel is positioned relative to the pressure side serpentine cooling channel such that a cooling fluid flow direction through the suction side serpentine cooling channel is generally opposite to the cooling fluid flow in adjacent portions of the pressure side serpentine cooling channel, thereby forming cooling fluid counterflow between the pressure side and suction side serpentine cooling channels.

14. The turbine blade of claim 13, wherein the pressure side serpentine cooling channel in contact with the pressure sidewall of the generally elongated blade is a triple pass serpentine cooling channel, and the suction side serpentine cooling channel in contact with the suction sidewall of the generally elongated blade is a quadruple pass serpentine cooling channel.

15. The turbine blade of claim 14, further comprising a plurality of trip strips in the suction side serpentine cooling channel and a plurality trip strips in the pressure side serpentine cooling channel.

16. The turbine blade of claim 14, further comprising a plurality of impingement orifices in a rib positioned between the at least one leading edge cooling channel and the pressure side serpentine cooling channel and adapted to allow cooling fluids to pass from the pressure side serpentine cooling channel to the at least one leading edge cooling channel and impinge on an inner surface of the wall forming the leading edge.

17. The turbine blade of claim 14, wherein the at least one trailing edge cooling channel is formed from a plurality of vortex chambers positioned in series and generally parallel to the trailing edge of the generally elongated blade for creating vortices from the cooling fluids, and wherein orifices in a first rib extending between adjacent vortex chambers are offset along a longitudinal axis of the elongated blade relative to orifices in another rib extending between vortex chambers.

18. The turbine blade of claim 14, wherein the at least one trailing edge cooling channel includes a plurality of impingement orifices in a rib separating the mid-chord cooling chamber and the at least one trailing edge cooling channel.

19. A turbine blade, comprising:

a generally elongated blade having a leading edge, a trailing edge, a tip section at a first end, a root coupled to the blade at an end generally opposite the first end for supporting the blade and for coupling the blade to a disc, and at least one cavity forming a cooling system in the blade;

the cooling system, comprising;

at least one leading edge cooling channel positioned in close proximity to the leading edge of the generally elongated blade;

at least one trailing edge cooling channel positioned in close proximity to the trailing edge of the generally elongated blade;

a bifurcated mid-chord cooling chamber positioned between the at least one leading edge cooling channel and the at least one trailing edge cooling channel, wherein the mid-chord cooling channel includes a pressure side serpentine cooling channel in contact with a pressure sidewall of the generally elongated blade and a suction side serpentine cooling channel in contact with a suction sidewall of the generally elongated blade and separated from the at least one pressure side serpentine cooling channel by a mid-chord rib;

an aperture in the mid-chord rib providing a cooling fluid passageway between the pressure and suction side serpentine cooling channels,

wherein the aperture is positioned in the mid-chord rib to exhaust cooling fluids from the pressure side serpentine cooling channel and to supply cooling fluids to the suction side serpentine cooling channel; and

wherein the at least one trailing edge cooling channel is formed from at least one vortex chamber for creating vortices from the cooling fluids.

20. A turbine blade, comprising:

a generally elongated blade having a leading edge, a trailing edge, a tip section at a first end, a root coupled to the blade at an end generally opposite the first end for supporting the blade and for coupling the blade to a disc, and at least one cavity forming a cooling system in the blade;

the cooling system, comprising;

at least one leading edge cooling channel positioned in close proximity to the leading edge of the generally elongated blade;

at least one trailing edge cooling channel positioned in close proximity to the trailing edge of the generally elongated blade;

a bifurcated mid-chord cooling chamber positioned between the at least one leading edge cooling channel and the at least one trailing edge cooling channel, wherein the mid-chord cooling channel includes a pressure side serpentine cooling channel in contact with a pressure sidewall of the generally elongated blade and a suction side serpentine cooling channel in contact with a suction sidewall of the generally elongated blade and separated from the at least one pressure side serpentine cooling channel by a mid-chord rib;

an aperture in the mid-chord rib providing a cooling fluid passageway between the pressure and suction side serpentine cooling channels;

wherein the aperture is positioned in the mid-chord rib to exhaust cooling fluids from the pressure side serpentine cooling channel and to supply cooling fluids to the suction side serpentine cooling channel; and

wherein the at least one trailing edge cooling channel includes a plurality of impingement orifices in a rib separating the mid-chord cooling chamber and the at least one trailing edge cooling channel.