Reducing inter-seal gap in gas turbine

A device for reducing inter-seal gap in gas turbines. Embodiments of a gas turbine with a first arcuate component adjacent to a second arcuate component; a first slot and a connected second slot on an end of the first arcuate component; a first seal disposed into the first slot and a first adjacent slot on the second arcuate component; a second seal disposed into the second slot and a second adjacent slot on the second arcuate component, leaving a gap between the first seal and the second seal; and a connector coupled to the first seal and the second seal and substantially covering the gap between the first seal and the second seal.

FIELD OF THE INVENTION

This invention relates generally to gas turbines and more particularly to a device for reducing inter-seal gap in gas turbines.

BACKGROUND OF THE INVENTION

The main gas-flow path in a gas turbine commonly includes the operational components of a compressor inlet, a compressor, a turbine and a gas outflow. There are also secondary flows that are used to cool the various heated components of the turbine. Mixing of these flows and gas leakage in general, from or into the gas-flow path, is detrimental to turbine performance.

The operational components of a gas turbine are contained in a casing. The turbine is commonly surrounded annularly by adjacent arcuate components. As used herein, the term “arcuate” may refer to a member, component, part, etc. having a curved or partially curved shape. The adjacent arcuate components include outer shrouds, inner shrouds, nozzle blocks, and diaphragms. Arcuate components may provide a container for the gas-flow path in addition to the casing alone. Arcuate components may secure other components of the turbine and may define spaces within the turbine. Between each adjacent pair of arcuate components is a space that permits the arcuate components to expand as the operation of the gas turbine forces the arcuate components to expand.

Slots are defined on the sides of each arcuate component for receiving a seal in cooperation with an adjacent slot of an adjacent arcuate component. The seal is placed in the slot to prevent leakage between the areas of the turbine on either side of the seal. These areas may include the main gas-flow path and secondary cooling flows.

The slots within the end of a particular arcuate component may be angled in orientation to each other and the slots may connect. When a planar seal is received in each of the two slots that are connected, a gap is left between the two seals. This gap permits leakage between the internal and external areas of the gas turbine. Reducing this gap improves gas turbine performance.

BRIEF DESCRIPTION OF THE INVENTION

A first aspect of the disclosure provides a gas turbine, comprising: a first arcuate component adjacent to a second arcuate component; a first slot and a connected second slot on an end of the first arcuate component; a first seal disposed into the first slot and a first adjacent slot on the second arcuate component; a second seal disposed into the second slot and a second adjacent slot on the second arcuate component, leaving a gap between the first seal and the second seal; and a connector coupled to the first seal and the second seal and substantially covering the gap between the first seal and the second seal.

A second aspect of the disclosure provides a gas turbine, comprising: a turbine including at least one annular arrangement of arcuate components; a first arcuate component adjacent to a second arcuate component, wherein the first arcuate component and second arcuate component are one of an outer shroud, an inner shroud, a nozzle block or a diaphragm; a first slot and a connected second slot on an end of the first arcuate component; a first seal disposed into the first slot and a first adjacent slot on the second arcuate component; a second seal disposed into the second slot and a second adjacent slot on the second arcuate component, leaving a gap between the first seal and the second seal; and a connector coupled to the first seal and the second seal and substantially covering the gap between the first seal and the second seal.

These and other aspects, advantages and salient features of the invention will become apparent from the following detailed description, which, when taken in conjunction with the annexed drawings, where like parts are designated by like reference characters throughout the drawings, disclose embodiments of the invention.

DETAILED DESCRIPTION OF THE INVENTION

“Referring toFIG. 1, a perspective view of one embodiment of a gas turbine2is shown. In this embodiment, gas turbine2includes a compressor inlet4, a compressor6, a plurality of combustors8, a compressor discharge (not shown), a turbine12including a plurality of turbine blades14, a rotor16and a gas outflow18. Compressor inlet4supplies air to compressor6. Compressor6supplies compressed air to combustors8where it mixes with fuel. Combustion gases from combustors8propels turbine blades12. Propelled turbine blades12rotate rotor16. A casing20forms an outer enclosure that encloses compressor inlet4, compressor6, plurality of combustors8, compressor discharge (not shown), turbine12, turbine blades14, rotor16and gas outflow18. Gas turbine2is only illustrative; teachings of the invention may be applied to a variety of gas turbines.”

“Referring toFIG. 2, a perspective view of one embodiment of an annular arrangement22of arcuate components24of turbine12of gas turbine2is shown. This view shows seven arcuate components24with one arcuate component removed for illustrative purposes. The end of each arcuate component24has slots26. Between each arcuate component24is a space28. A person skilled in the art will readily recognize that annular arrangement22may have any number of arcuate components24; that arcuate components24may be of varying shapes and sizes; and that arcuate components24may serve different functions in gas turbine2. For example, arcuate components in a turbine may include, but not be limited to, outer shrouds, inner shrouds, nozzle blocks, and diaphragms as discussed below.”

“Referring toFIG. 3, a cross-sectional view of one embodiment of turbine12of gas turbine2(FIG. 1) is shown. In this embodiment, casing20encloses a plurality of outer shrouds30, an inner shroud32, a plurality of nozzle blocks34, a plurality of diaphragms36, and turbine blades14. Each of the outer shrouds30, inner shroud32, nozzle blocks34and diaphragms36are arcuate components24. Each of the outer shrouds30, inner shrouds32, nozzle blocks34and diaphragms36have slots26in a side thereof. In this embodiment, outer shrouds30connect to casing20; inner shroud32connects to outer shrouds30; nozzle blocks34connect to outer shrouds30; and diaphragms36connect to nozzle blocks34. A person skilled in the art will readily recognize that many different arrangements and geometries of arcuate components are possible. Alternative embodiments, may include different arcuate components, more arcuate components, or less arcuate components.”

FIG. 4shows an end view of a first arcuate component38with a first slot42and a second slot44on an end of first arcuate component38. First slot42and second slot44are shown at an angle in relation to each other and connect to one another.FIG. 5shows a cross sectional axial view along line A-A inFIG. 4of first arcuate component38adjacent to second arcuate component40. The space28is left between first arcuate component and second arcuate component. A first adjacent slot46and a second adjacent slot48on second arcuate component40are shown. First adjacent slot46is connected to second adjacent slot48.

FIG. 4andFIG. 5also show a first seal50disposed into first slot42and a second seal52disposed into second slot44. The disposition of first seal50and second seal52leaves a gap54(FIG. 4) between first seal50and second seal52.FIG. 5shows first seal50disposed into first slot42and first adjacent slot46on second arcuate component40; and second seal52disposed into second slot44and second adjacent slot48on second arcuate component40.

FIG. 4andFIG. 5also show one embodiment in accordance with this invention of a connector56coupled to first seal50and second seal52and substantially covering gap54between first seal50and second seal52.

“In one embodiment of the invention, connector56is substantially the same width as first seal50and second seal52. In one embodiment, connector56, first seal50and second seal52include at least one of metal, a cloth-layer, a cloth-layer assemblage, and/or a foil-layer assemblage. For example metal, may include stainless steel and/or Inconel® from Huntington Alloys Corporation. Further, a cloth-layer, a cloth-layer assemblage, foil and/or a foil-layer assemblage as described in Dinc et al. (U.S. Pat. No. 5,657,998) may be used.FIG. 6shows a perspective partial cut-away view of a known seal58. Known seal58could represent first seal50, second seal52and/or connector56. Known seal58includes a foil-layer assemblage60and a cloth-layer assemblage62. The foil-layer assemblage60is an assemblage of overlying layers of foil. The foil comprises (and preferably consists essentially of) metal, ceramic, and/or polymer foil. The choice of materials for the foil and the choice of the thickness for a layer are made to meet the sealing and flexibility requirements of a particular seal or connector application. In one embodiment, as shown inFIG. 6, the foil-layer assemblage60may have a first foil layer64and a second foil layer66. In another embodiment, for added flexibility, the first and second foil layers64and66each have slots68. The cloth layer assemblage62is an assemblage of overlying layers of cloth. A cloth layer comprises (and preferably consists essentially of) metal, ceramic, and/or polymer fibers which have been woven, knitted or pressed into a layer of fabric. The choice of layer construction (i.e. woven, knitted or pressed), the choice of materials for the cloth, and the choice of the thickness for a layer are made to meet the wear resistance, flexibility, and sealing requirements of a particular seal or connector application. In one embodiment, as shown inFIG. 6, the cloth-layer assemblage62may have a first cloth layer70and a second cloth layer72. A person skilled in the art will readily recognize that connector56, first seal50and second seal52may be composed of many materials. In one embodiment, connector56may include a flexible material, for example, more slots68(FIG. 6) are included. In another embodiment, first seal50and second seal52may include a semi-rigid material, for example, fewer slots68(FIG. 6) are included. Connector56may be more flexible than first seal50and second seal52. Connector56, first seal50and second seal52may be substantially planar. In one embodiment of the invention, connector56, first seal50and second seal52are substantially rectangular; however, this is not necessary in all cases. In one embodiment, connector56, first seal50and second seal52are substantially elongate; for example, the thickness of the connector56, first seal50and/or second seal52is thin relative to length.

FIG. 7shows a top view andFIG. 8shows a side view of first seal50and second seal52and connector56with connector56coupled to first seal50and second seal52with a plurality of attachments80in accordance with one embodiment of this invention. First seal50has a first seal end74(FIG. 8) and second seal52has a second seal end76(FIG. 8). First seal50and second seal52may be aligned first seal end74to second seal end76with a space78(FIG. 8) between first seal50and second seal52. Connector56covers space78between first seal50and second seal52and first seal end74and second seal end76. In one embodiment of this invention, the connector56is substantially the same width as first seal50and second seal52. However, connector56may be a different width than first seal50and/or second seal52. Each attachment80may include, for example, at least one of a spot weld or a tack. Attachments80are illustrated inFIG. 8partially protruding above connector56. However, attachments80may be flush or inset relative to connector56. Other attachments may also be used to secure connector56to first seal50and second seal52. For example,FIG. 9shows one embodiment of the invention in a top view of first seal50and second seal52and connector56with connector56coupled to the first seal50and the second seal52with an adhesive. A person skilled in the art will readily recognize many ways for coupling connector56to first seal50and second seal52without visible attachments.

FIG. 10shows one embodiment of the invention in a side view of first seal50and second seal52and connector56as a unitary continuous material. In this embodiment, connector56may be thinner than first seal50and second seal52thereby making the connector56more flexible relative to first seal50and second seal52.

Gas turbine2is only illustrative; teachings of the invention may be applied to any machine that disposes two or more seal components leaving a gap.

While various embodiments are described herein, it will be appreciated from the specification that various combinations of elements, variations or improvements therein may be made by those skilled in the art, and are within the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.