WO2016010556A1

WO2016010556A1 - Seal usable between a transition and a turbine vane assembly in a turbine engine

Info

Publication number: WO2016010556A1
Application number: PCT/US2014/047193
Authority: WO
Inventors: Shankar P. SRINIVASAN; Ashtad Kotwal; Ovidiu Timotin; Luke MINNICK
Original assignee: Siemens Aktiengesellschaft; Siemens Energy, Inc.
Priority date: 2014-07-18
Filing date: 2014-07-18
Publication date: 2016-01-21

Abstract

A seal (10) usable to seal a transition (12) in a can-annular combustion system (14) of a turbine engine 916) to a turbine vane assembly (18) to direct exhaust gases through the turbine vane assembly (18) is disclosed. The seal (10) may be formed from an elongated body (20) extending at least partially circumferentially and one or more hot lips (22) extending axially from the elongated body (20). One or more cold lips (24) may be coupled to the elongated body (20) radially inward of the hot lip (22) and extending axially from the elongated body (20) to form a receiving cavity (26) between the hot lip (22) and the cold lip (24). The cold lip (24) may be formed from a resilient material capable of enduring contact with an adjacent row one vane rail (28). In at least one embodiment, the cold lip (24) may be formed from a different material than a material used to form the elongated body (20) and the hot lip (22).

Description

SEAL USABLE BETWEEN A TRANSITION AND

A TURBINE VANE ASSEMBLY IN A TURBINE ENGINE

FIELD OF THE INVENTION

This invention is directed generally to transitions in turbine engines between combustors and turbine vane assemblies for directing exhaust gases into the turbine vane assemblies and, more particularly, to devices that function as seals between transitions and turbine vane assemblies. BACKGROUND

Turbine engines typically combust a mixture of fuel and air in a combustion chamber and pass the exhaust gases produced in the combustion chamber through a turbine vane assembly to drive the turbine assembly. Typically, a plurality of transitions couple a combustor to a turbine vane assembly in a can-annular system. During operation of a turbine engine, exhaust gases flow through the transitions and into the turbine vane assemblies. Seals couple the transitions to the turbine vane assemblies to prevent an undesirable air mixture, such as to prevent an excess amount of air from mixing with the combustion gases. The seals prevent gases from outside the transition to enter and mix combustion gas flow. Conventional seals are often manufactured from rigid materials that are unable to absorb movement and vibrations, thereby resulting in fatigue and premature failure. Thus, a need exists for a seal configured to couple a transition to a turbine vane assembly and

accommodate the significant thermal distortion and wear experienced in this location.

SUMMARY OF THE INVENTION

A seal usable to seal a transition in a can-annular combustion system of a turbine engine to a turbine vane assembly to direct exhaust gases through the turbine vane assembly is disclosed. The seal may be formed from an elongated body extending at least partially circumferentially and one or more hot lips extending axially from the elongated body. One or more cold lips may be coupled to the elongated body radially inward of the hot lip and extending axially from the elongated body to form a receiving cavity between the hot lip and the cold lip. The cold lip may be formed from a resilient material capable of enduring contact with an adjacent row one vane rail. In at least one embodiment, the cold lip may be formed from a different material than a material used to form the elongated body and the hot lip. The cold lip may be attached to the elongated body after manufacture and use of the seal, such as a retrofit of the seal. In another embodiment, the cold lip may be attached to the elongated body during the original manufacturing process of the seal.

In at least one embodiment, the seal may be usable to seal a transition to a turbine vane assembly in a gas turbine engine. The seal may be formed from an elongated body extending at least partially circumferentially and one or more hot lips extending axially from the elongated body. The seal may also include one or more cold lips coupled to the elongated body radially inward of the hot lip and extending axially from the elongated body to form a receiving cavity between the hot lip and the cold lip. The cold lip may be formed from a different material than a material used to form the elongated body and the at least one hot lip. The cold lip may be formed from a wear resistant material. In at least one embodiment, the cold lip may be formed from a HAYNES 25 material. The cold lip may have a thickness in a radially direction between about 1/8 of an inch and about 1/2 of an inch. In at least one embodiment, the cold lip may have a thickness in a radially direction of about 1/4 of an inch. The cold lip may be coupled to the elongated body via at least one weld after formation of the elongated body. The cold lip may be generally aligned with the at least one hot lip. A radially outer surface of the cold lip may be generally aligned with a radially inner surface of the hot lip.

The hot lip may be integrally formed with the elongated body. The hot lip may have a generally linear outer surface in an axial direction and a curved outer surface in a circumferential direction. The elongated body may also include a hook formed from a radially extending shank arm extending from an axial end of the elongated body opposite to the at least one hot lip, an axially extending throat extending axially from a radially inner end of the radially extending shank arm, and a radially

extending hook arm extending radially outward from an end of the axially extending throat opposite to the end to which the radially extending shank arm is attached. The radially extending hook arm may be shorter in length than the radially extending shank arm. An opening in a throat of the hook may be generally orthogonal to an opening in the receiving cavity.

An advantage of the seal of the invention is that the cold lip is formed from a material that is more resilient and wear resistant than the material forming the elongated body, and thus the cold lip has a longer life than if the elongated body and cold lip were formed from the same material.

Another advantage of the seal is that the seal may be retrofitted by installing a cold lip formed from a more wear resistant material to an elongated body of the seal to increase the useful life of the seal.

Yet another advantage of the seal is that by installing the cold lip formed from a different material, the seal is prevented from having to be scraped whenever the cold lip experiences wear and thermal distortion.

Another advantage of the seal is that the cold lip formed from a more wear resistant material may enable the seal's life to be extended from about 12,000 engine operating hours to between 16,000 and 24,000 engine operating hours.

These and other embodiments are described in more detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and form a part of the specification, illustrate embodiments of the presently disclosed invention and, together with the description, disclose the principles of the invention.

Figure 1 is a longitudinal cross-sectional view of an intersection between a transition and a turbine vane assembly in a turbine engine and includes a seal having aspects of this invention.

Figure 2 is a perspective view of the seal shown in Figure 1 .

Figure 3 is an axial view looking upstream of the seal shown in Figure 1 .

Figure 4 is a side view of the seal shown in Figure 3.

DETAILED DESCRIPTION OF THE INVENTION

As shown in Figures 1 -4, a seal 10 usable to seal a transition 12 in a can- annular combustion system 14 of a turbine engine 16 to a turbine vane assembly 18 to direct exhaust gases through the turbine vane assembly 18 is disclosed. The seal 10 may be formed from an elongated body 20 extending at least partially circumferentially and one or more hot lips 22 extending axially from the elongated body 20. One or more cold lips 24 may be coupled to the elongated body 20 radially inward of the hot lip 22 and extending axially from the elongated body 20 to form a receiving cavity 26 between the hot lip 22 and the cold lip 24. The cold lip 24 may be formed from a resilient material capable of enduring contact with an adjacent row one vane rail 28. In at least one embodiment, the cold lip 24 may be formed from a different material than a material used to form the elongated body 20 and the hot lip 22. The cold lip 24 may be attached to the elongated body 20 after manufacture and use of the seal 10, such as a retrofit of the seal 10. In another embodiment, the cold lip 24 may be attached to the elongated body during the original manufacturing process of the seal 10.

The seal 10 may be usable to seal a transition 12 to a turbine vane assembly 18 in a gas turbine engine 16. The seal 10 may include the elongated body 20 extending at least partially circumferentially and one or more hot lips 22 extending axially from the elongated body 20. The seal 10 may also include one or more cold lips 24 coupled to the elongated body 20 radially inward of the hot lip 22 and extending axially from the elongated body 20 to form a receiving cavity 26 between the hot lip 22 and the cold lip 24. The cold lip 24 may be formed from a different material than a material used to form the elongated body 20 and the hot lip 22. In at least one embodiment, the cold lip 24 may be formed from a wear resistant material that is more resistant to wear than the material used to form the hot lip 22. In at least one embodiment, the cold lip 24 may be formed from a HAYNES 25 material or other appropriate material.

In at least one embodiment, the cold lip 24 may have a thickness in a radially direction between about 1/8 of an inch and about 1/2 of an inch. In another embodiment, the cold lip 24 may have a thickness in a radially direction of about 1/4 of an inch. The cold lip 24 may be generally aligned with the hot lip 22. A radially outer surface 30 of the cold lip 24 may be generally aligned with a radially inner surface 32 of the hot lip 22. In at least one embodiment, the cold lip 24 may be coupled to the elongated body 20 via one or more joints 35, which may be a weld, after formation of the elongated body 20. The hot lip 22 may be integrally formed with the elongated body 20 or may be a separate component attached to the elongated body 20. The hot lip 22 may have a generally linear outer surface 34 in an axial direction, which may also be curved in a circumferential direction.

The elongated body 20 may also include a hook 38 formed from a radially extending shank arm 40 extending from an axial end 42 of the elongated body 20 opposite to the hot lip 22. The hook 38 may include an axially extending throat 44 extending axially from a radially inner end 46 of the radially extending shank arm 40. The radially extending hook arm 50 may extend radially outward from an end 52 of the axially extending throat 44 opposite to the end 54 to which the radially extending shank arm 40 is attached. The radially extending hook arm 50 may be shorter in length than the radially extending shank arm 40. An opening 56 in a throat 58 of the hook 38 may be generally orthogonal to an opening 56 in the receiving cavity 26.

In at least one embodiment, the cold lip 24 may be formed from a HAYNES 25 material and may be joined to an elongated body formed from HASTELLOY X by any suitable low heat input low distortion joining process. In at least one

embodiment, the weld may be, but is not limited to being, about 0.25" thick with a circumferentially extending arc. An exemplary joining process may include the following action items. The cold lip 24 may be machined to size, bent into the required shape and pre-weld heat treated prior to welding. The HASTELLOY X blank should be pre-weld heat treated before welding. The cold lip 24 and the elongated body 20 may be at room temperature or at elevated temperature when joined. Spacers may be used between the cold lip 24 and the elongated body 20 to reduce, if not eliminate, distortion. The cold lip 24 and the elongated body 20 to be joined may be tack welded prior to welding. Run-on and run-off tabs may be used to maintain steady welding conditions in the actual production weld. The joint should be a full penetration weld with minimum width and reinforcement on the face and on the root. Concavity on the root and face should be avoided. The joint design may be a butt square weld with a maximum fit-up gap of 0.005 inch (0.13 mm) and, a maximum joint surface mismatch of 0.040 inch (1 mm). The joining process may be an autogenous fusion welding using a laser energy source. The welding type may be automatic. Any laser energy source, such as, but not limited to, fiber, for example, diode, carbon dioxide, Nd-YAG, could be used for welding. The weld joint may be achieved by a single pass or multipass welding. The weld transition seal containing the cold lip 24 may be post weld heat treated after the joining operation.

In at least one example, the cold lip 24 was welded autogenously using a high power laser energy source, such as, but not limited to a PRECO (IPG) fiber laser. A full penetration joint was achieved in a single pass with a suitable travel speed. The cold lip 24 was cold bent to shape prior to welding. Both the elongated body 20 and the cold lip 24 were heat treated prior to and after welding.

Alternative approaches for joining the cold lip 24 to the elongated body 20 include other fusion welding processes, such as, but not limited to, plasma arc welding, gas tungsten welding, gas metal arc welding and variants of these processes. Alternative approaches could incorporate a beveled joint design in conjunction with multipass welding using a filler metal.

During operation of a turbine engine to which the seal is attached, thermal expansion and vibrations cause the cold lip 24 of the seal 10 to rub against a row one vane rail positioned within the receiving cavity 26. Because the cold lip 24 is formed from a material that is more resilient and wear resistant than the material forming the elongated body 20, the cold lip 24 has a longer life than if the elongated body 20 and cold lip 24 were formed from the same material.

The foregoing is provided for purposes of illustrating, explaining, and describing embodiments of this invention. Modifications and adaptations to these embodiments will be apparent to those skilled in the art and may be made without departing from the scope or spirit of this invention.

Claims

CLAIMS We claim:

1 . A seal (10) usable to seal a transition (12) to a turbine vane assembly (18) in a gas turbine engine (16), characterized in that:

an elongated body (20) extending at least partially circumferentially and at least one hot lip (22) extending axially from the elongated body (20);

at least one cold lip (24) coupled to the elongated body (20) radially inward of the at least one hot lip (22) and extending axially from the elongated body (20) to form a receiving cavity (26) between the at least one hot lip (22) and the at least one cold lip (24); and

wherein the at least one cold lip (24) is formed from a different material than a material used to form the elongated body (20) and the at least one hot lip (22).

2. The seal (10) of claim 1 , characterized in that the at least one cold lip (24) is formed from a wear resistant material.

3. The seal (10) of claim 2, characterized in that the at least one cold lip (24) is formed from a HAYNES 25 material.

4. The seal (10) of claim 1 , characterized in that the at least one cold lip (24) has a thickness in a radially direction between about 1/8 of an inch and about 1/2 of an inch.

5. The seal (10) of claim 4, characterized in that the at least one cold lip (24) has a thickness in a radially direction of about 1/4 of an inch.

6. The seal (10) of claim 1 , characterized in that the at least one cold lip (24) is coupled to the elongated body (20) via at least one weld (35) after formation of the elongated body (20).

7. The seal (10) of claim 1 , characterized in that the at least one cold lip (24) is generally aligned with the at least one hot lip (22).

8. The seal (10) of claim 1 , characterized in that a radially outer surface (30) of the at least one cold lip (24) is generally aligned with a radially inner surface (32) of the at least one hot lip (22).

9. The seal (10) of claim 1 , characterized in that the at least one hot lip (22) is integrally formed with the elongated body (20).

10. The seal (10) of claim 1 , characterized in that the at least one hot lip (22) has a generally linear outer surface 934) in an axial direction and a curved outer surface in a circumferential direction.

1 1 . The seal (10) of claim 1 , characterized in that the elongated body (20) further comprises a hook (38) formed from a radially extending shank arm (40) extending from an axial end (42) of the elongated body (20) opposite to the at least one hot lip (22), an axially extending throat (44) extending axially from a radially inner end (46) of the radially extending shank arm (40), and a radially extending hook arm (50) extending radially outward from an end (52) of the axially extending throat (44) opposite to the end (54) to which the radially extending shank arm (40) is attached.

12. The seal (10) of claim 1 1 , characterized in that the radially extending hook arm (50) is shorter in length than the radially extending shank arm (40).

13. The seal (10) of claim 1 1 , characterized in that an opening in a throat (58) of the hook (38) is generally orthogonal to an opening (56) in the receiving cavity (26).