Pressurized serpentine cooling channel construction for open-circuit liquid cooled turbine buckets

Claim 2

In a vane structure adapted for mounting in a rotating element of a machine wherein the airfoil surfaces of the vane are subjected to contact with hot gas, the vane comprising an airfoil-shaped core and a conforming skin affixed thereto, said core and said skin defining at least one open-ended subsurface passage therebetween for the transit of coolant therethrough, said at least one passage being adapted to receive coolant flow at the radially inner end thereof from a source of coolant and to discharge the coolant flow from the radially outer end thereof into a chordwise-extending manifold, said manifold in turn being adapted to discharge coolant flow from said vane, the improvement in which: a. said at least one passage has a substantially constant depth along the length thereof and is disposed in a convoluted configuration with most of each successive convolution extending in the generally chordwise direction and b. means for self-establishment of a liquid seal with the coolant flow, said means being located in and stationary relative to the root of said vane and being in series flow communication between said source of coolant and said at least one passage, the reverse flow of coolant vapor from said at least one passage being prevented thereby.

Claim 3

The improvement of claim 1 wherein a plurality of subsurface passages of convoluted configuration are employed, each passage being arranged in a serpentine pattern confined to one face of the vane and each passage having separate Liquid seal-establishing means in series flow communication therewith.

Claim 4

The improvement of claim 2 wherein one face of the vane is provided with a plurality of separate subsurface serpentine cooling patterns.

Claim 5

The improvement of claim 1 wherein the liquid seal-establishing means is a tubular member having an inverted U in the length thereof.

Claim 6

In a gas turbine wherein a turbine disk is mounted on a shaft rotatably supported in a casing, said turbine disk extending substantially perpendicular to the axis of said shaft and having turbine buckets affixed to the outer rim thereof, each bucket comprising an airfoil-shaped core and a conforming skin affixed thereto, said buckets receiving a driving force from a hot motive fluid moving in a direction generally parallel to said axis of said shaft and the driving force being transmitted to said shaft via said turbine disk, means located radially inward of said buckets for introducing liquid coolant within said turbine in a radially outward direction to enter an open-ended coolant distribution circuit comprising in the airfoil of each of said buckets at least one subsurface cooling channel defined by said core and said skin, said at least one cooling channel being adapted to receive liquid coolant at the radially inner end thereof, and a manifolding and discharge portion located in the radially outer end region of the airfoil of the given bucket, said manifolding and discharge portion being in flow communication with the radially outer end of said at least one cooling channel, the improvement in the above combination comprising: a. at least one annular gutter region forming part of the rim of said turbine disk to receive liquid coolant, b. said at least one subsurface cooling channel being of a substantially constant depth along the length thereof and being arranged in a convoluted configuration with most of each of the successive convolutions extending in the generally chordwise direction, the radially inner end of said convoluted configuration being in flow communication with said gutter region and c. means for self-establishment of a liquid seal with the coolant flow, said means being stationary relative to and in series between said gutter region and said radially inner end, the reverse flow of coolant vapor from said convoluted configuration being prevented thereby.

Claim 7

In a gas turbine wherein a turbine disk is mounted on a shaft rotatably supported in a casing, said turbine disk extending substantially perpendicular to the axis of said shaft and having turbine buckets affixed to the outer rim thereof, each bucket comprising an airfoil-shaped core and a conforming skin affixed thereto, said buckets receiving a driving force from a hot motive fluid moving in a direction generally parallel to said axis of said shaft and the driving force being transmitted to said shaft via said turbine disk, means located radially inward of said buckets for introducing liquid coolant within said turbine in a radially outward direction to enter an open-ended coolant distribution circuit comprising in the airfoil of each of said buckets at least one subsurface cooling channel defined by said core and said skin, said at least one cooling channel being adapted to receive liquid coolant at the radially inner end thereof, and a manifolding and discharge portion located in the radially outer end region of the airfoil of the given bucket, said manifolding and discharge portion being in flow communication with the radially outer end of said at least one cooling channel, the improvement in the above combination comprising: a. at least one annular gutter region forming part of the rim of said turbine disk to receive liquid coolant, b. said at least one subsurface cooling channel being of a substantially constant depth along the length thereof and being arranged in a convoluted configuration with most of each of the successive convolutions extending in the generally chordwise direction, the radially inner end of said convoluted configuration being in flow communication with said gutter region and c. means for self-establishment of a liquid seal with the coolant flow, said means being stationary relative to and in series between said gutter region and said radially inner end, the reverse flow of coolant vapor from said convoluted configuration being prevented thereby.

Claim 8

The improvement of claim 5 wherein the inner end of the convoluted configuration is connected to the liquid seal establishing means by a closed conduit having as part of the length thereof a subsurface cooling passage of convoluted configuration located in platform structure at the base of the airfoil.

Claim 9

The improvement of claim 6 wherein the airfoil of the given bucket is provided with a plurality of subsurface cooling channels of convoluted configuration, each of said channels being connected to a separate closed conduit in flow communication with a separate liquid seal establishing means, said closed conduit having as part of the length thereof a subsurface cooling passage of serpentine configuration located in the platform structure.

Claim 10

The improvement of claim 5 wherein the liquid seal-establishing means is a tubular member having an inverted U in the length thereof.

Claim 11

The improvement of claim 8 wherein the liquid seal establishing means is disposed substantially radially of the turbine disk.

Claim 12

The improvement of claim 5 wherein the maximum pitch for the convoluted configuration is about 0.6 inch.