Transition Duct Exit Holder and Inlet Ring Support Arrangement

A gas turbine engine has a transition duct supporter that is able to support and accommodate the operation of the gas turbine engine. The transition duct supporter is located between a metallic integrated exit piece and a transition duct that is made of ceramic matrix composites.

BACKGROUND

Disclosed embodiments are generally related to gas turbine engines and, more particularly to the transition system used in gas turbine engines.

2. Description of the Related Art

A gas turbine engine typically has a compressor section, a combustion section having a number of combustors and a turbine section. Ambient air is compressed in the compressor section and conveyed to the combustors in the combustion section. The combustors combine the compressed air with a fuel and ignite the mixture creating combustion products. The combustion products flow in a turbulent manner and at a high velocity. The combustion products are routed to the turbine section via transition ducts. Within the turbine section are rows of vane assemblies. Rotating blade assemblies are coupled to a turbine rotor. As the combustion product expands through the turbine section, the combustion product causes the blade assemblies and turbine rotor to rotate. The turbine rotor may be linked to an electric generator and used to generate electricity.

During the operation of gas turbine engines strong forces are generated that can impact the structure of the gas turbine engine. These forces may occur in the transition duct. Accommodating these forces to avoid breakage is important for the continued operation of the gas turbine engine.

SUMMARY

Briefly described, aspects of the present disclosure relate to the transition system of a gas turbine engine.

An aspect of the disclosure may be a gas turbine engine comprising a combustor basket; a transition duct connected to the combustor basket, wherein the transition duct has a crown portion forming a first curved surface and an inlet extension piece connected to the transition duct with a transition duct supporter. The transition duct support comprises a crown holder, wherein the crown holder has a first holder portion having a second curved surface and a second holder portion having a third curved surface, wherein the second curved surface and third curved surface interfaces with the first curved surface; and a seal portion secured to the crown holder, wherein the seal portion abuts the inlet extension piece thereby inhibiting the flow of air.

Another aspect of the present disclosure may be a gas turbine engine comprising; a combustor basket; a transition duct connected to the combustor basket, wherein the transition duct has a crown portion forming a first curved surface; and an inlet extension piece connected to the transition duct with a transition duct supporter. The transition duct supporter comprises; a crown lock, wherein the crown lock has a second curved surface that interfaces with the first curved surface; a seal portion abutting the inlet extension piece thereby inhibiting the flow of air; and a spacer separating the crown lock from the seal portion, wherein the seal portion and the crown lock are secured together through the spacer.

Still another aspect of the present disclosure may be a transition duct supporter for use in gas turbine engines having a crown holder, wherein the crown holder has a first holder portion having a first curved surface and a second holder portion having a second curved surface, wherein the first curved surface and second curved surface interfaces with a third curved surface of a crown portion formed on a transition duct; and a seal portion secured to the crown holder, wherein the seal portion abuts an inlet extension piece thereby inhibiting the flow of air.

DETAILED DESCRIPTION

To facilitate an understanding of embodiments, principles, and features of the present disclosure, they are explained hereinafter with reference to implementation in illustrative embodiments. Embodiments of the present disclosure, however, are not limited to use in the described systems or methods.

FIGS. 1 and 2show a view of the transition system in a gas turbine engine100. Shown are the spool piece4and the structural support cone5which surrounds and structurally protects the combustor basket12. Also shown is the transition duct6connected to the combustor basket12at the upstream end of the transition duct6and the integrated exit piece (IEP)8at the downstream end of the transition duct6. Working gases flow downstream from the combustor basket12through the transition duct6and then through the IEP8. In the embodiment shown the IEP8is made of metallic material while the transition duct6is made of ceramic matrix composites (CMC). The use of CMC material for the transition duct6while having a metallic IEP8encourages use of the transition duct supporter10in order to accommodate the different responses the materials have to thermal changes that occur during operation of the gas turbine engine100.

Transition duct supporter10is located between the transition duct6and the IEP8. The transition duct supporter10helps maintain the orientation of the transition duct6with respect to the IEP8and combustor basket12during operation of the gas turbine engine100. The transition duct supporter10allows small amounts of swivelling of the transition duct6during installation of the transition duct6to the IEP8and during operation of the gas turbine engine100. The transition duct supporter10further seals the gap that exists between the IEP8and the transition duct6. The transition duct supporter10also supports the transition duct6during gas flow thrust load while allowing yielding during thermal deformations and displacements.

FIGS. 3-7show close up cross-sectional views of the transition duct supporter10. The transition duct supporter10has a crown holder22and a seal portion27. The seal portion27has a first seal layer24and a second seal layer25. The first seal layer24faces towards the interior of the transition duct6. The second seal layer25faces towards the exterior of the transition duct6.

The crown holder22has a first holder portion23and a second holder portion26. The first holder portion23is located upstream of the second holder portion26. The first holder portion23has a first curved surface28that curves and extends in the upstream direction, i.e. towards the combustor basket12. The second holder portion26has a second curved surface29that curves and extends in the downstream direction, i.e. towards the IEP8. While a first holder portion23and second holder portion26are shown, it should be understood that this can be formed as a single unitary piece. The seal portion27and the crown holder22have holes2,3, and4(shown clearly inFIGS. 8 and 9) that receive bolts18, which are secured by nuts19. The bolts18and nuts19secure the seal portion27and the crown holder22together.

The transition duct6has a crown portion15that extends circumferentially around the circumference of the transition duct6. The crown portion15may be made of continuous fiber layers in order to avoid any shearing that may occur to the crown portion15. Alternatively the crown portion15may be made of an integrally formed material.

The crown portion15may have a curved surface21that is formed from the continuous fibrous layers. The curved surface21may form an arc that may extends between a chord length of 10.0 mm to 80.0 mm, and more preferably 20.0 mm to 70.0 mm. The curved surface21may rise off the transition duct6between a distance of between 1.0 mm to 20.0 mm, and more preferably between 5.0 mm and 15.0 mm.

The first holder portion23may have a curved surface28that engages a portion of the curved surface21. The second holder portion26may have a curved surface29that engages a portion of the curved surface21. In the embodiment shown, each of the curved surfaces28,29forms an arc length of between 10.0 mm to 80.0 mm, and more preferably between 25.0 mm and 70.0 mm. The shapes of curved surfaces28,29preferably correspond to the shape of the curved surface21.

In the embodiment shown there is a cooling reservoir43between the curved surfaces28,29of the first holder portion23and the second holder portion26. The cooling reservoir43results from the first holder portion23curving in the upstream direction and the second holder portion26curving in the downstream direction when installed on the transition duct6. Air enters through cooling air supply holes44formed on the first holder portion23into the cooling reservoir43and exits through purge holes45formed on the second holder portion26. The cooling reservoir43cools the crown portion15and supplies purge air into the cavity behind the flange of the IEP8.

The curved surfaces28,29of the first holder portion23and the second holder portion26accommodate movements in radial and axial directions of the transition duct6that occur during the operation of the gas turbine engine100.

Seal portion27has a first layer24and second layer25. First layer24and second layer25can be used to be shifted circumferentially to create an offset and form a shiplap between segments. The shiplap can form a seal. The gas path side will be filled with cool purge air and prevents ingestion of combustion gases. The first layer24faces internally with respect to the IEP8and the transition duct6. The second layer25faces externally with respect to the IEP8and the transition duct6. The seal portion27abuts the IEP8thereby inhibiting the flow of air through the gap that is formed during the connection of the IEP8and the transition duct6. The seal portion27may generally have a U shape when viewed in cross-section. However, it should be understood that other shapes are contemplated, such as J shaped, L-shaped (discussed below), C shaped, etc. The shape of the seal portion27should be such that it is able to inhibit the flow of air that occurs in the gas turbine engine100through the gap formed between the IEP8and the transition duct6.

Referring now toFIGS. 8-9, the transition duct supporter10extends around the entire circumference of the transition duct6. It should be understood that the various components of the transition duct supporter10may be continuous or segmented. When the components of the transition duct supporter10are segmented the individual components are able to be more flexible than when maintained as an integrated whole. Furthermore, first holder portion23and second holder portion26are preferably segmented for installation.FIGS. 8 and 9show the various components of the transition duct supporter10being installed around the surface of the transition duct6. From these figures it can be seen that the various segments of the transition duct support10may be ship lapped so as to provide more structural integrity when fully assembled. In the embodiment shown inFIGS. 8 and 9, each of the first support portions23and the second support portions26may form an arc of 120°, however it should be understood that other configurations may be formed using more or less first support portions23and second support portions26so that the arc length may be different. The same holds true for seal portion27assembled around the transition duct26, which forms an arc of 120° as shown inFIG. 7, but may form other arc lengths.

As shown inFIG. 8, the seal portion27may be arranged so that the edges where each seal portion27meets another seal portion27do not align with where each first support portion23meets another first support portion23and each second support portion26meets another second support portion26.

FIGS. 10-12show an alternative embodiment that uses transition duct supporter30. The transition duct supporter30has a crown lock32, spacer33and seal portion37having a first layer34and second layer35.

As discussed above, the transition duct6has a crown portion15that extends circumferentially around the circumference of the transition duct6. The crown portion15may be made of a continuous fiber layers in order to avoid any shearing that may occur to the duct crown15. Alternatively the crown portion15may be an integrated single piece. The crown portion15has a curved surface31. The curved surface31may form an arc that extends between a chord length of between 10.0 mm-80.0 mm, and more preferably between 25.0 mm and 70.0 mm. The arc surface may rise off the transition duct between a distance of between 1.0 mm-20.0 mm and more preferably between 5.0 mm to 15.0 mm.

Crown lock32is formed from a unitary piece that has a curved surface36that corresponds to the curved surface31of the crown portion15. In the embodiment shown, the curved surface36has an arc length of between 20.0 mm to 80.0 mm, and more preferably between 25.0 mm and 70.0 mm. The curved surface36of the crown lock32and the curved surface31of the crown portion15accommodates movements in a radial and axial direction of the transition duct6that occurs during the operation of the gas turbine engine100. The crown lock32may be one of a plurality of crown locks32. The plurality of the crown locks32may be spaced circumferentially around the transition duct6. Alternatively the crown lock32may be an integrated piece. Having the crown lock32be segmented permits additional flexibility of the transition duct supporter30during operation of the gas turbine engine100. The segmentation also facilitates installation of the crown lock32.

Seal portion37has a first layer34and second layer35. First layer34and second layer35are used to reduce rigidity and can be used to form a shiplap. The first layer34faces internally. The second layer35faces externally. The first layer34may have flex slots39. The flex slots39are located on the first layer34where the seal portion37inhibits the flow of air. The flex slots39are able to accommodate deformations that may occur during the operation of the gas turbine engine100. Accommodation of the deformations can assist in maintaining the structural integrity of the transition duct supporter30as well as the IEP8and the transition duct6.

The seal portion37abuts the IEP8thereby inhibiting the flow of air through the gap that is formed during the connection of the IEP8and the transition duct6. The seal portion37may generally have an L shape when viewed in cross section. At the distal end of the seal portion37, located proximate to the curved surface36, there is a lip formed so as to prevent damage to the crown portion15and the crown lock32during operation of the gas turbine engine100. However, it should be understood that other shapes are contemplated, such as J shaped, C shaped, etc. The shape of the seal portion37should be such that it is able to inhibit the flow of air that occurs in the gas turbine engine100.

The transition duct supporter30extends around the entire circumference of the transition duct6. It should be understood that the various components of the transition duct supporter30may be continuous or segmented. When the components of the transition duct supporter30are segmented the individual components are able to be more flexible than when maintained as an integrated whole.

Also forming part of the transition duct supporter30is spacer33. Spacer33accommodates bolt19and secures the transition duct supporter30to the crown lock32.

FIG. 13shows an embodiment where there is a ball joint38that forms part of the spacer33. The ball joint38forms part of the transition duct supporter30in order to provide additional flexibility. The ball joint33is spherically shaped and moves within a cavity41formed within the crown lock32. The cavity41is shaped and sized to accommodate movement of the ball joint33.

Crown lock32is formed from a unitary piece that has a curved surface36that corresponds to the curved surface31of the crown portion15. In the embodiment shown, the curved surface36and31has an arc length of between 10.0 mm to 80.0 mm, and more preferably between 25.0 mm and 70.0 mm. The curved surface36of the crown lock32and the curved surface31of the crown portion15accommodates movements in the radial and axial direction of the transition duct6that occurs during the operation of the gas turbine engine100. The crown lock32may be one of a plurality of crown locks32spaced circumferentially around the transition duct6. Alternatively the crown lock32may be an integrated piece. Having the crown lock32be segmented permits additional flexibility of the transition duct supporter30during operation of the gas turbine engine100.