Transition duct honeycomb seal
View Patent ↗A sealing device for use between a gas turbine combustor transition duct aft frame and a turbine inlet having improved durability, reduced wear on the mating turbine vane, and reduced manufacturing costs, is disclosed. The sealing device has a circumferential length, an axial width, and a radial height and contains a plurality of channels extending axially along the seal inner surface for passing a controlled amount of cooling air to a turbine inlet. The sealing device is formed of abradable honeycomb having a plurality of honeycomb cells with the honeycomb cells oriented to ensure maximum control against cooling air leakage while also providing maximum flexibility during assembly. The sealing device is captured between the transition duct aft frame, bulkhead, and turbine vane platform, thereby allowing easy replacement of the seal without requiring major disassembly of the transition duct aft frame section.
1. A sealing device for use between a gas turbine combustor transition duct aft frame and a turbine inlet, said sealing device comprising:
a first end and a second end in spaced relation thereby forming a circumferential length;
a forward face and an aft face in spaced relation thereby forming an axial width;
an inner surface and an outer surface in spaced relation thereby forming a radial height;
a plurality of channels extending axially along said inner surface, said channels having a channel width and channel depth, said channels capable of passing a controlled amount of a cooling fluid through said sealing device to cool vane platforms at said turbine inlet; and,
wherein said sealing device is formed of abradable honeycomb having a plurality of honeycomb cells, each cell having a wall thickness and a cell width.
2. The sealing device of claim 1 wherein said channel width is at least 0.100 inches.
3. The sealing device of claim 2 wherein said channel width is at least 1.2 times greater than said channel depth.
4. The sealing device of claim 1 wherein said cooling fluid is compressed air.
5. The sealing device of claim 1 wherein said wall thickness of said honeycomb is approximately between 0.0014 inches and 0.003 inches.
6. The sealing device of claim 1 wherein said cell width is approximately between 0.062 inches and 0.125 inches.
7. A gas turbine transition duct sealing system comprising:
a transition duct for transferring hot gases from a combustor to a turbine, said transition duct having an aft frame with at least one bulkhead attached to said aft frame;
a sealing device fixed to said at least one bulkhead, said sealing device comprising:
a first end and second end in spaced relation thereby forming a circumferential length;
a forward face and an aft face in spaced relation thereby forming an axial width;
an inner surface and an outer surface in spaced relation thereby forming a radial height;
a plurality of channels extending axially along said inner surface, said channels having a channel width and channel depth;
wherein said sealing device if formed of abradable honeycomb having a plurality of honeycomb cells, each cell having a wall thickness and a cell width;
a turbine inlet region having a plurality turbine vanes, each of said turbine vanes having at least one platform region;
wherein said sealing device is in sealing contact with said bulkhead, said aft frame, and said platform region.
8. The sealing system of claim 7 wherein said channel width is at least 0.100 inches.
9. The sealing system of claim 8 wherein said channel width is at least 1.2 times greater than said channel depth.
10. The sealing system of claim 7 wherein said channels pass a controlled amount of compressed air to cool vane platforms at said turbine inlet.
11. The sealing system of claim 7 wherein said wall thickness is approximately between 0.0014 inches and 0.003 inches.
12. The sealing system of claim 7 wherein said cell width is approximately between 0.062 inches and 0.125 inches.
13. The sealing system of claim 7 wherein said sealing device is fixed to said bulkhead by a means such as brazing.