WO2017192147A1

WO2017192147A1 - Flow metering device for gas turbine engine

Info

Publication number: WO2017192147A1
Application number: PCT/US2016/031214
Authority: WO
Inventors: Anthony L. SCHIACO; Benjamin G. Hettinger
Original assignee: Siemens Aktiengesellschaft; Siemens Energy, Inc.
Priority date: 2016-05-06
Filing date: 2016-05-06
Publication date: 2017-11-09

Abstract

A gas turbine engine has a flow metering device located between the combustor and the transition duct. The flow metering device engages the transition duct with a spring device. The flow metering device meters the airflow and axially centers the transition duct and the combustor while providing axial slipping during operation of the gas turbine engine.

Description

FLOW METERING DEVICE FOR GAS TURBINE ENGINE

BACKGROUND

[0001] 1. Field

[0002] Disclosed embodiments are generally related to gas turbine engines and, more particularly to the transition system used in gas turbine engines.

[0003] 2. Description of the Related Art

[0004] A gas turbine engine may have 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.

[0005] 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 ducts. Accommodating these forces to avoid breakage is important for the continued operation of the gas turbine engine.

SUMMARY

[0006] Briefly described, aspects of the present disclosure relate to the connection between the combustor and transition duct in gas turbine engines.

[0007] An aspect of the disclosure may be a gas turbine engine comprising a combustor having an outlet section; a transition duct having an inlet section; a flow metering device connecting the outlet section and the inlet section, wherein the flow metering device comprises a spring device that engages the transition duct, wherein the spring device has a plurality of spring sections extending around a perimeter of the spring device, wherein the spring sections permit centering of the transition duct with respect to the combustor; and wherein the flow metering device stabilizes the flow of air into the combustor.

[0008] Another aspect of the present disclosure may be a flow metering device for use in a gas turbine engine comprising a flow metering section that stabilizes airflow in a gas turbine engine; a spring device that engages a transition duct and is connected to the flow metering section, wherein the spring device has a plurality of spring sections extending around a perimeter of the spring device, wherein the spring sections permit centering of the transition duct with respect to a combustor; and a flow transformation section that connects to a combustor and is connected to the flow metering section.

[0009] Still another aspect of the present disclosure may be a gas turbine engine comprising a combustor having an outlet section; a transition duct having an inlet section; a flow metering device comprising; a flow metering section that meters airflow in the gas turbine engine; a spring device engaging the transition duct and connected to the flow metering section, wherein the spring device has a plurality of spring sections extending around a perimeter of the spring device, wherein the spring sections permit centering of the transition duct with respect to a combustor; a flow transformation section connected to the combustor and connected to the flow metering section and; and wherein the flow metering device stabilizes the flow of air into the combustor.

BRIEF DESCRIPTION OF THE DRAWINGS [0010] Fig. 1 shows a cross section of a gas turbine engine.

[0011] Fig. 2 shows a view of a inlet extension piece, a transition duct and a flow metering device.

[0012] Fig. 3 is a view of the flow metering device.

[0013] Fig. 4 is a view of the flow metering device showing its separate components.

[0014] Fig. 5 is a close up view of the flow metering section.

[0015] Fig. 6 is a cut-away view of the combustor and the transition duct. [0016] Fig. 7 shows a close-up cut-away view of the engagement of the flow metering device to the transition duct.

[0017]

[0018] Fig. 8 shows a close-up cut-away view of the engagement of the flow metering device to the transition duct with an alternative embodiment of the spring sections.

[0019] Fig. 9 shows a close-up view of the engagement of the flow metering device to the transition duct having anti-rotation features.

[0020]

DETAILED DESCRIPTION

[0021] 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.

[0022] The components and materials described hereinafter as making up the various embodiments are intended to be illustrative and not restrictive. Many suitable components and materials that would perform the same or a similar function as the materials described herein are intended to be embraced within the scope of embodiments of the present disclosure.

[0023] Fig. 1 shows a cross section of a gas turbine engine 100. Shown in the figure are combustor 8 and transition duct 12. Combustion products flow downstream from the combustor 8 and through the transition duct 12. During this process the transition duct 12 has to accommodate vibrations and thermal deformations. Preferably the transition duct 12 will remain concentric with respect to the combustor 8 during operation of the gas turbine engine 100.

[0024] Fig. 2 is a view of an exit frame 11 , a transition duct 12 and a flow metering device 20. The exit frame 1 1 is at the end of the transition duct 12 and is connected downstream from the flow metering device 20 and combustor 8. The inlet section 14 of the transition duct 12 is where the flow metering device 20 engages the transition duct 12.

[0025] With reference to Fig. 2 and the other figures, the flow metering device 20 that is shown is made of three components, flow metering section 24, spring device 26 and the flow transformation section 28. The flow metering device 20 stabilizes the flow of air that moves through the gas turbine engine 100 into the combustor 8, discussed further below. While the figures illustrate the flow metering device 20 being made from three separate components it should be understood that some or all of the components may be constructed as a single integrated piece. [0026] Compressed air is forced into the gas turbine engine 100. The air flows around the components in the gas turbine engine 100, cooling and heating the components during operation. The movement of the air in and around obstacles causes pressure and velocity instability of the air entering the intake of the combustor 8. The instability of the air flow is rectified by having the air flow through the flow metering device 20. The flow metering device 20 allows a measured flow of air and creates circumferential flow balancing as the air enters into the combustor 8. The balanced flow provides uniformity to the fuel mixing and the combustion reaction.

[0027] The flow metering section 24 meters the flow of air in the gas turbine engine 100. The flow metering section 24 has circular holes 13, slots 15 and elliptical holes 16. The circular holes 13, slots 15 and elliptical holes 16 permit air to flow through the flow metering section 24 in a controlled fashion. The air flow moves through the circular holes 13, slots 15 and elliptical holes 16 in the upstream direction towards the combustor 8. This movement of air subdues the turbulence of the air flow. While regular patterns for the holes are shown, asymmetric hole patterns may also be used to further benefit the combustion performance.

[0028] The elliptical holes 16 are located at the distal end of the flow metering section 24 proximate to the spring device 26. Slots 15 extend from the elliptical holes 16 to the opposite end of the flow metering section 24. The slots 15 are formed in the flow metering section 24 and run the length of the flow metering section 24 so as to bisect a plurality of circular holes 13 and elliptical holes 16. The elliptical holes 16 and the slots 15 are able to accommodate the thermal deformations and stress that occurs during operation of the gas turbine engine 100. The major axis of the elliptical holes 16 is preferably perpendicular to the slot 15 so as to dissipate the concentration of stresses that impact the flow metering section 24. Without the presence of these features there is an increased chance of there being structural failure with respect to the flow metering section 24 [0029] The overall shape of the flow metering section 24 is aerodynamically shaped. In the present embodiment the conical shape of the flow metering section 24 conveys a benefit to the aerodynamics of the flow metering section 24. It should be understood that while the flow metering section 24 is shown as being conically shaped, the flow metering section 24 may take other shapes such as cylindrical, conical, bulged shape, eccentric cone shaped or transitional free form. These other shapes may be employed depending upon the geometry of the components found within the gas turbine engine 100. The aerodynamic shape of the flow metering section 24 further assists in metering the air flow in the gas turbine engine 100. The aerodynamic shape of the flow metering section 24 directs the flow of air in a controlled manner over and through the flow metering device 20.

[0030] As shown, the diameter Dl of the flow metering section 24 is smaller in the location proximate to the spring device 26. Further upstream of the transition duct 12 the diameter D2 of the flow metering section 24 is larger than the diameter Dl of the flow metering section 24 located proximate to the spring device 26. As shown, the flow metering section 24 has its largest diameter D2 at the location where the flow metering section 24 is connected to the flow transformation section 28.

[0031] The spring device 26 is located further downstream from the combustor 8 than the flow metering section 24. The spring device 26 is connected to the flow metering section 24 via a weld, brazing or other acceptable method of connection. The spring device 26 is a ring and has a plurality of spring sections 27. Each of the spring sections 27 is biased against the inlet section 14 of the transition duct 12. The spring sections 27 may be a rectangular shape. However, it should be understood that the spring sections may take other shapes provided they are biased against the inlet section 14 and assist in preventing airflow through the connection. Having spring sections 27 be a rectangular shape can provide maximum surface area for the spring sections 27 and ensure a secure fit for the spring device 26. The spring sections 27 are further designed to provide compression force on the inlet section 14 at cold build and through the thermal transients of operation of the gas turbine engine 100. The spring device 26 also serves as a damping device against the resonations coming from the dynamics of the combustion process. Other embodiments of the spring sections 27 may be employed, for example as shown and discussed with respect to Fig. 7.

[0032] Each of the spring sections 27 are joined to a connecting band 18 that forms a ring. A ring shape is formed in order to correspond to the shape of the flow metering section 24. However, similar to the flow metering section 24, other shapes and geometries may be used depending on the overall geometries employed in the gas turbine engines 100. The spring section 27 should maintain the same shape as the flow metering section 24 in order to be fully connected to the flow metering section 24. Alternatively each of the spring sections 27 are formed together with the connecting band 19. By having a plurality of spring sections 27 the spring device 26 is able to be biased against the inlet section 14 around its entire circumference. As well as maintain concentricity of the transition duct 12 with respect to the combustor 8.

[0033] A flow transformation section 28 is connected to the upstream end of the flow metering section 24. The diameter D3 of the flow transformation section 28 connected to the flow metering section 24 is larger than the diameter D2 of the flow metering section 28. It should be understood that in alternative embodiments the diameter D3 may be smaller than the diameter D2 provided that the flow transformation section 28 is able to be connected to the flow metering section 24. The flow transformation section 28 is aerodynamic conically shaped so that the diameter D4 located proximate to the combustor 8 is smaller than the diameter D3 located proximate to the flow metering section 24. The aerodynamic shape further assists in controlling the airflow.

[0034] The flow transformation section 28 is connected to the flow metering section 24 via bolts 19, shown in Fig. 2, inserted through flow metering section bolt hole 29 and flow transformation section bolt hole 21. The bolts 19 extend through both and can be used to offset the flow metering device 20 from the outer casing portal that may surround the combustor 8 and the transition duct 12. [0035] Fig. 6 shows a cut-away view of the engagement of the flow metering device 20 to the inlet section 14 of the transition duct 12. Shown in Fig. 6 are the spring sections 27 of the spring device 26 biased against the surface of the inlet section 14. This permits the flow metering device 20 to limit leakage, accommodate thermal deformation, thermal elongation, and provides concentricity of the transition duct 12 with respect to the combustor 8. Flow metering device 20 also dampens vibration of the transition duct 27 and combustor 8 that can occur during operation of the gas turbine engine 100.

[0036] Fig. 7shows a cut-away view of the engagement of the flow metering device 20 to the inlet section 14 of the transition duct 12. Spring section 27 of the spring device 26 is shown biased against the inlet section 14. This view further shows a basket spring clip 9 employed to assist in the connection with the combustor 8 and the concentricity of the transition duct 12 with respect to the combustor 8.

[0037] Fig. 8 shows an alternative embodiment of the spring device 26 where the individual spring sections 27 are arranged such that two layers of spring sections 27 are ship-lapped with respect to each other. Having the spring sections 27 ship-lapped or layered can be used to further inhibit leakage that occurs.

[0038] Fig. 9 shows an alternative embodiment wherein the flow metering section 24 has spring sections 27 formed integrally with the flow metering section 24. Located between each of the spring sections 27 are anti-rotation slots 33 having a rectangular shape. The anti-rotation slots 33 are formed and sized to receive anti- rotation lock piece 31. The anti-rotation lock piece 31 is formed as part of the inlet section 14. As shown the anti-rotation lock piece 31 also has a rectangular shape and engages the anti-rotation slots 33 so that flow metering section 24 does not rotate while connected to the inlet section 14. While the anti-rotation slots 33 and the anti- rotation lock pieces 31 are shown as rectangular shaped, it should be understood that other shapes for these components may be used provided the rotation of the flow metering section 24 with respect to the inlet section 14 is prevented.

[0039] While embodiments of the present disclosure have been disclosed in exemplary forms, it will be apparent to those skilled in the art that many modifications, additions, and deletions can be made therein without departing from the spirit and scope of the invention and its equivalents, as set forth in the following claims.

Claims

What is claimed is:

1. A gas turbine engine comprising:

a combustor having an outlet section;

a transition duct having an inlet section;

a flow metering device connecting the outlet section and the inlet section, wherein the flow metering device comprises a spring device that engages the transition duct, wherein the spring device has a plurality of spring sections extending around a perimeter of the spring device, wherein the spring sections permit centering of the transition duct with respect to the combustor; and

wherein the flow metering device stabilizes the flow of air into the combustor.

2. The gas turbine engine of claim 1, wherein the flow metering device further comprises a flow metering section, wherein the flow metering section is conically shaped.

3. The gas turbine engine of claim 2, wherein the flow metering section has a plurality of slots.

4. The gas turbine engine of claim 3, wherein the flow metering section has a plurality of circular holes and a plurality of elliptical holes interconnected by the slots.

5. The gas turbine engine of claim 1, wherein the flow metering device further comprises a flow transformation section.

6. The gas turbine engine of claim 5, wherein the flow transformation section is conically shaped.

7. The gas turbine engine of claim 1 , wherein the spring device forms a ring.

8. The gas turbine engine of claim 1 , wherein a conical flow metering device is connected to a flow transformation section.

9. The gas turbine engine of claim 1 , wherein the flow metering device further comprises a flow metering section and a flow transformation section, wherein the flow metering section and the flow transformation section are aerodynamic shaped, and wherein the larger end of the flow metering section is connected to larger end of the flow transformation section.

10. A flow metering device for use in a gas turbine engine comprising:

a flow metering section that stabilizes airflow in a gas turbine engine;

a spring device that engages a transition duct and is connected to the flow metering section, wherein the spring device has a plurality of spring sections extending around a perimeter of the spring device, wherein the spring sections permit centering of the transition duct with respect to a combustor; and

a flow transformation section that connects to a combustor and is connected to the flow metering section.

11. The flow metering device of claim 10, wherein the flow metering section is conically shaped.

12. The gas turbine engine of claim 10, wherein the flow metering section has a plurality of slots.

13. The gas turbine engine of claim 12, wherein the flow metering section has a plurality of circular holes and a plurality of elliptical holes interconnected by the slots.

14. The flow metering device of claim 10, wherein the spring device forms a ring.

15. The flow metering device of claim 10, wherein the flow metering section is conically shaped, wherein the flow transformation section is conically shaped and wherein the larger end of the flow metering section is connected to larger end of the flow transformation section.

16. A gas turbine engine comprising:

a combustor having an outlet section; a transition duct having an inlet section;

a flow metering device comprising;

a flow metering section that meters airflow in the gas turbine engine; a spring device engaging the transition duct and connected to the flow metering section, wherein the spring device has a plurality of spring sections extending around a perimeter of the spring device, wherein the spring sections permit centering of the transition duct with respect to a combustor;

a flow transformation section connected to the combustor and connected to the flow metering section; and

wherein the flow metering device stabilizes the flow of air into the combustor.

17. The gas turbine engine of claim 16, wherein the flow metering section is conically shaped.

18. The gas turbine engine of claim 17, wherein the flow metering section has a plurality of holes providing metering of air flow.

19. The gas turbine engine of claim 18, wherein the flow transformation section is conically shaped.

20. The gas turbine engine of claim 19, wherein the larger end of the flow metering section is connected to larger end of the flow transformation section.