EP2562359A2

EP2562359A2 - Turbine nozzle vane retention system

Info

Publication number: EP2562359A2
Application number: EP12180006A
Authority: EP
Inventors: Thomas J. Brunt; Robert W. Coign
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 2011-08-24
Filing date: 2012-08-10
Publication date: 2013-02-27
Also published as: CN102953769A; US20130052024A1

Abstract

The present application provides a turbine nozzle vane retention system (100). The turbine nozzle vane retention system (100) may include a number of nozzles (120) with a platform (150), a slot (230) extending into the platform (150), and a pin (280) extending between the slot (230) of a first nozzle (121) and the slot (230) of a second nozzle (122).

Description

TECHNICAL FIELD

The present application and the resultant patent relate generally to gas turbine engines and more particularly relate to a turbine nozzle vane retention system using a retention pin about a nozzle inner platform to retain the inner platform and/or other components in case of failure.

BACKGROUND OF THE INVENTION

In gas turbine engines, thermally induced stresses may lead to cracking in the turbine nozzles. If, for example, a crack propagates through the entire length of a nozzle airfoil, the inner platform of the nozzle will no longer be retained in place. Parts of the platform and/or other components therefore may dislodge and cause catastrophic damage to the downstream flow path components.
In doublet or triplet nozzle designs (two or three airfoils per nozzle segment), the increased number of airfoils provides a certain amount of redundancy against catastrophic failure given the multiple load paths. Should a single airfoil crack and/or oxidize severely, the adjacent airfoils still may retain the inner platform in place. In a singlet design (one airfoil per segment), however, a large section of the nozzle, the airfoil, and/or the platform may dislodge if not retained at the inner and outer diameters. Moreover, the risk of damage by a singlet nozzle inner platform increases as gas turbine engine temperatures increase. Specifically, the nozzle base material generally may be unable to withstand the operating gas temperatures for long durations if the nozzle cooling delivery system is compromised.
There is thus a desire for an improved turbine nozzle vane retention system. Such a nozzle vane retention system should retain at least the inner platform of a singlet nozzle in the event of overall nozzle failure.

SUMMARY OF THE INVENTION

The present invention provides a turbine nozzle vane retention system. The turbine nozzle vane retention system may include a number of nozzles with a platform, a slot extending into the platform, and a pin extending between the slot of a first nozzle and the slot of a second nozzle.
These and other features and improvements of the present application and the resultant patent will become apparent to one of ordinary skill in the art upon review of the following detailed description when taken in conjunction with the several drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:

Fig. 1 is a schematic diagram of a gas turbine engine.
Fig. 2 is a partial side view of a turbine stage showing a turbine nozzle vane retention system as may be described herein.
Fig. 3 is a partial perspective view of the turbine nozzle and the turbine nozzle vane retention system of Fig. 2.
Fig. 4 is a partial side view of the pin of the turbine nozzle vane retention system extending between a pair of nozzles.

DETAILED DESCRIPTION

Referring now to the drawings, in which like numerals refer to like elements throughout the several views, Fig. 1 shows a schematic view of gas turbine engine 10 as may be used herein. The gas turbine engine 10 may include a compressor 15. The compressor 15 compresses an incoming flow of air 20. The compressor 15 delivers the compressed flow of air 20 to a combustor 25. The combustor 25 mixes the compressed flow of air 20 with a compressed flow of fuel 30 and ignites the mixture to create a flow of combustion gases 35. Although only a single combustor 25 is shown, the gas turbine engine 10 may include any number of combustors 25. The flow of combustion gases 35 is in turn delivered to a turbine 40. The flow of combustion gases 35 drives the turbine 40 so as to produce mechanical work. The mechanical work produced in the turbine 40 drives the compressor 15 via a shaft 45 and an external load 50 such as an electrical generator and the like.
The gas turbine engine 10 may use natural gas, various types of syngas, and/or other types of fuels. The gas turbine engine 10 may be anyone of a number of different gas turbine engines offered by General Electric Company of Schenectady, New York and the like. The gas turbine engine 10 may have different configurations and may use other types of components. Other types of gas turbine engines also may be used herein. Multiple gas turbine engines, other types of turbines, and other types of power generation equipment also may be used herein together.
Figs. 2 and 3 show an example of a turbine nozzle vane retention system 100 as may be described herein. The turbine nozzle vane retention system 100 will be described herein in the context of a first stage 110 of the turbine 40. In this example, the turbine 40 may be part of a heavy duty gas turbine engine. The turbine nozzle vane retention system 100, however, may be applicable to many different types of turbines and components thereof.
Generally described, the first stage 110 includes a first stage nozzle 120 and a first stage bucket 130. Any number of nozzles 120 and buckets 130 may be arranged in annular arrays in the hot gas path of the turbine 40. The first stage nozzle 120 includes an outer platform 140, an inner platform 150, and an airfoil 160 therebetween. Although a singlet design 170 with only one airfoil 160 is shown, multiple airfoils 160 also may be used. The outer platform 140 may be secured to a shroud 180, an outer casing, a retaining ring, and the like. The inner platform 150 bears against an inner support ring 190, an inner casing, and the like. Other components and other configurations may be used herein.
The outer platform 140 may include one or more outer seal slots 200. Likewise, the inner platform 150 may include any number of inner seals slots 210. The seal slots 200, 210 may be formed in the platforms 140, 150 via an EDM process (electric discharge machining) or other types of manufacturing techniques. A compliant seal 220 may be positioned within the seal slots 200, 210. The compliant seal 220 links adjacent nozzles 120. In the example of Fig. 4, a first nozzle 121 and a second nozzle 122 are shown. Any number of nozzles 120 may be used. Other components and other configurations may be used herein.
The turbine nozzle vane retention system 100 also includes a slot 230 formed in the inner platform 150. The slot 230 may extend the width of the inner platform 150. Alternatively, a first slot 231 may be formed on a pressure side 240 of the nozzle 120 and a second slot 232 may be formed on a suction side 250 of the nozzle 120. The slot 230 is shown on a forward leg 260 of the inner platform 150, but any convenient location on the inner platform 150 or elsewhere may be used. The slot 230 is shown as having a circular 270 shape, but a triangular, rectangular, or any multi-faceted slot 230 may be used herein. The slot 230 may have any desired size. The slot 230 may be machined or cast into the inner platform 150. EDM and other types of manufacturing process also may be used herein.
The turbine nozzle vane retention system 100 also includes a pin 280 for positioning within the slot 230. The pin 280 may be any type of rigid element with sufficient material strength so as to maintain the inner platforms 150 in position. The term "pin" thus refers to any rigid linking feature that may be used herein. The pin 280 also may have a circular shape 290 or any shape or size corresponding to the shape of the slot 230.
In use, the pin 280 may be positioned within the slots 230 of circumferentially adjacent nozzles 120. In the event of the failure of a nozzle 120, the pin 280 and the slots 230 of the turbine nozzle vane retention system 100 will transmit the gas path pressure loads to adjacent undamaged nozzles 120 so as to prevent a damaged inner platform 150 from being released into the gas path. The turbine nozzle vane retention system 100 thus maintains the inner platform 150 in place until the gas turbine engine 10 is brought down for maintenance and the damaged nozzle section may be replaced. The turbine nozzle vane retention system 100 thus prevents such damage and the associated downtime and replacement costs.
It should be apparent that the foregoing relates only to certain embodiments of the present application and the resultant patent. Numerous changes and modifications may be made herein by one of ordinary skill in the art without departing from the general spirit and scope of the invention as defmed by the following claims and the equivalents thereof.
Various aspects and embodiments of the present invention are defined by the following numbered clauses:

1. A turbine nozzle vane retention system, comprising:
- a first nozzle and a second nozzle;
- the first nozzle and the second nozzle both comprising an airfoil and an inner platform with a slot extending therein; and
- a pin extending between the slot of the first nozzle and the slot of the second nozzle.
2. The turbine nozzle vane retention system of clause 1, wherein the slot comprises a plurality of slots.
3. The turbine nozzle vane retention system of clause 1 or 2, wherein the slot comprises a circular or a multi-faceted shape.
4. The turbine nozzle vane retention system of any of clauses 1 to 3, wherein the pin comprises a circular or a multi-faceted shape.
5. The turbine nozzle vane retention system of any of clauses 1 to 4, wherein the inner platform comprises a forward leg and wherein the slot is positioned within the forward leg.
6. The turbine nozzle vane retention system of any of clause 1 to 5, wherein the pin extends from a pressure side of the slot of the first nozzle to a suction side of the slot of the second nozzle.
7. The turbine nozzle vane retention system of any of clause 1 to 6, wherein the slot is machined or cast into the platform.
8. A turbine nozzle vane retention system, comprising:
- a plurality of nozzles;
- each of the plurality of nozzles comprising a single airfoil and an inner platform;
- one or more slots extending through the inner platform; and
- a pin extending between a first slot of a first nozzle and a second slot of a second nozzle.

Claims

A turbine nozzle vane retention system (100), comprising:
a plurality of nozzles (120);

each of the plurality of nozzles (120) comprising a platform (150);

a slot (230) extending into the platform (150); and

a pin (280) extending between the slot (230) of a first nozzle (121) and the slot (230) of a second nozzle (122).
The turbine nozzle vane retention system (100) of claim 1, wherein the slot (230) comprises a plurality of slots (231, 232).
The turbine nozzle vane retention system (100) of claim 1 or 2, wherein the slot (230) comprises a circular or a multi-faceted shape (270).
The turbine nozzle vane retention system (100) of any of claims 1 to 3, wherein the pin (280) comprises a circular or a multi-faceted shape (290).
The turbine nozzle vane retention system (100) of any of claims 1 to 4, wherein the platform (150) comprises a forward leg (260) and wherein the slot (230) is positioned within the forward leg (260).
The turbine nozzle vane retention system (100) of any of claims 1 to 5, wherein the platform (150) comprises one or more seal slots (210) with a compliant seal therein (220).
The turbine nozzle vane retention system (100) of any preceding claim, wherein the pin (280) extends from a pressure side (240) of the slot (230) of the first nozzle (121) to a suction side (250) of the slot (240) of the second nozzle (122).
The turbine nozzle vane retention system (100) of any preceding claim, wherein the platform (150) comprises an inner platform (150).
The turbine nozzle vane retention system (100) of claim 8, further comprising an outer platform (140).
The turbine nozzle vane retention system (100) of any preceding claim, wherein the slot (230) is machined or cast into the platform.
The turbine nozzle vane retention system (100) of any preceding claim, wherein each of the plurality of nozzles (120) comprises an airfoil (160).
The turbine nozzle vane retention system (100) of any preceding claim, wherein each of the plurality of nozzles (120) comprises a singlet design (170).