CN110017178B

CN110017178B - Hot gas path component for a gas turbine

Info

Publication number: CN110017178B
Application number: CN201811359969.2A
Authority: CN
Inventors: A.钱尼; S.索佩; R.穆克
Original assignee: Ansaldo Energia Switzerland AG
Current assignee: Ansaldo Energia Switzerland AG
Priority date: 2017-11-15
Filing date: 2018-11-15
Publication date: 2023-06-16
Anticipated expiration: 2038-11-15
Also published as: EP3486431A1; CN110017178A; EP3486431B1

Abstract

A hot gas path component for a gas turbine engine includes a tubular wall structure (25) and a plurality of cooling passages (27) extending through the tubular wall structure between an upstream end (28) and a downstream end (29) of the tubular wall structure. An inner portion (33) of the tubular wall structure defined between the inner surface (30) and the cooling channel has a first thickness (T1), and an outer portion (35) of the tubular wall structure defined between the outer surface (31) and the cooling channel has a second thickness (T2) that is greater than the first thickness (T1). The cooling channel has a radial height (H) defined by a maximum radial distance across the cooling channel (27) between the inner portion (33) and the outer portion (35) of the tubular wall structure (25), and the radial height (H) of the cooling channel (27) is greater than the first thickness (T1) of the inner portion (33) of the tubular wall structure (25).

Description

Hot gas path component for a gas turbine

Cross reference to related applications

The present application claims priority from european patent application No. 17201913.5 filed on date 2017, 11, 15, the disclosure of which is incorporated by reference.

Technical Field

The invention relates to a hot gas path component for a gas turbine engine.

Background

As is known, the combustor of a gas turbine engine includes a hot gas path inside which fuel is mixed with air and combusted. The hot gases thus produced are then fed to a turbine or expansion section of a gas turbine engine for converting thermal and kinetic energy into mechanical energy.

The hot gas path is essentially defined by a tubular wall with a hot inner surface and a cold outer surface, and may be formed of several components. The hot gas path component may include one or more combustion sections defining corresponding combustion spaces (e.g., in the case of sequential combustors), and a transition duct. The transition duct is configured to direct hot gas into the turbine inlet and thus is exposed to high temperatures. Like other components of the gas turbine engine, the components defining the hot gas path (and in particular the transition duct) also require cooling to avoid damage caused by overheating and to extend life. For the purpose of cooling the hot gas path components, a portion of the total air flow is generally taken from the compressor and fed to the cooling system through a plenum surrounding the combustor. Several kinds of known cooling systems may be used, such as impingement cooling systems, convection cooling systems or near wall cooling systems. However, all known systems suffer from limitations that do not allow for further increases in the combustion temperature within the hot gas path (as would be desirable), but in fact or otherwise affect the operation of the gas turbine device. Typical limitations are large pressure losses compared to the cooling effect achieved, air consumption reducing engine efficiency, especially affecting the heat extraction of the near wall cooling system. Near wall cooling in fact utilizes small cooling channels which are provided within the hot gas path wall and thus very close to the hot surface of the hot gas path wall and are in principle quite efficient. However, small channels can only carry small air streams that heat up rapidly. Thus, the known near wall cooling systems are actually efficient for cooling short portions of the hot gas path wall, but the cooling effect drops rapidly over longer distances.

In addition to the thermal load, the hot gas path components also need to withstand the rather severe mechanical stresses caused by mechanical and/or thermo-acoustic vibrations that may occur during operation of the gas turbine engine. For this reason, the hot gas wall of the can-combustor is typically relatively thick to provide the required mechanical resistance. However, the greater thickness of the wall conflicts with the cooling efficiency of the impingement and convection arrangements.

Disclosure of Invention

It is an object of the present invention to provide a hot gas path component for a gas turbine engine which allows overcoming or at least weakening the described limitations.

According to the present invention there is provided a hot gas path component comprising:

a tubular wall structure having an upstream end, a downstream end, an inner surface, and an outer surface;

a plurality of cooling passages extending through the tubular wall structure between the upstream end and the downstream end;

wherein an inner portion of the tubular wall structure defined between the inner surface and the cooling channel has a first thickness and an outer portion of the tubular wall structure defined between the outer surface and the cooling channel has a second thickness greater than the first thickness; and, in addition, the processing unit,

wherein the cooling channel has a radial height defined by a maximum radial distance across the cooling channel between the inner portion and the outer portion of the tubular wall structure, and the radial height of the cooling channel is greater than the first thickness of the inner portion of the tubular wall structure.

The hot gas path component thus combines an effective cooling action with mechanical strength to withstand both severe thermal and mechanical loads. In practice, on the one hand, the cooling channels may be provided at a short distance from the inner surface of the tubular wall structure (which is directly exposed to the hot gas). Therefore, heat dissipation is efficient. On the other hand, the cooling channels extend radially through a considerable amount of the overall thickness of the tubular wall structure, thus facilitating the passage of a sufficient flow of cooling air. Thus, not only can the cooling channels extend very close to the inner surface, but the heat extraction can also be kept low. At the same time, the outer portion of the tubular wall structure is thick enough to provide the required mechanical resistance without affecting heat dissipation.

According to another aspect of the invention, the second thickness is two to five times the first thickness.

The ratio of the first thickness to the second thickness indicated above helps to ensure both cooling effect at the inner surface, and mechanical resistance.

According to another aspect of the invention, the radial height of the cooling channel is at least three times the first thickness of the inner portion of the tubular wall structure.

The ratio of radial height to first thickness indicated above helps to ensure low heat extraction in the cooling air flow.

According to another aspect of the invention, the radial height is greater than the width of the cooling channel.

According to another aspect of the invention, adjacent cooling channels are separated from each other by a membrane transverse to the inner and outer portions of the tubular wall structure.

The diaphragm provides the dual function of mechanically connecting the inner portion with the outer portion of the tubular wall structure and dissipating heat (thereby acting as a dissipating fin).

According to another aspect of the invention, the diaphragm is substantially perpendicular to the inner and outer portions of the tubular wall structure.

According to another aspect of the invention, the septum forms an angle between 30 ° and 90 ° with the inner portion and the outer portion of the tubular wall structure.

The angled diaphragm adds flexibility to the tubular wall structure, thus substantially reducing sensitivity to vibration and mechanical stress.

According to another aspect of the invention, the septum tapers from an inner portion to an outer portion of the tubular wall structure or from an outer portion to an inner portion of the tubular wall structure.

The tapered diaphragm allows a satisfactory compromise of mechanical and thermal properties of the tubular wall structure to be achieved. The thicker portions of the membrane increase stiffness and conductive heat transfer, however, the thinner portions cause thermal decoupling. Thus, thicker or thinner portions of the diaphragm may be provided at the inner or outer portions of the tubular wall structure to optimize heat dissipation, thermal decoupling, and mechanical resistance as desired.

According to another aspect of the invention, the cooling channel has a rectangular or parallelogram or trapezoid cross-section with rounded corners or without rounded corners, or an oval cross-section.

The shape and morphology of the cross-section can be selected to optimize the air flow and cooling effect as desired.

According to another aspect of the invention, the hot gas path component comprises at least one fin extending longitudinally from an inner portion of the tubular wall structure along at least one of the cooling channels.

Fins in the cooling channels further improve heat dissipation and cooling effectiveness.

According to another aspect of the invention, the cooling channels are uniformly distributed along the circumferential direction of the tubular wall structure.

In this way, a uniform cooling effect is achieved throughout the entire component.

According to another aspect of the invention, the cooling channel extends in the axial longitudinal direction of the tubular wall structure or along a spiral path around the longitudinal axis of the tubular wall structure.

The design of the cooling channels can thus be chosen to optimize the cooling effect as desired.

According to another aspect of the present invention there is provided a hot gas path assembly for a gas turbine engine comprising a hot gas path component as defined hereinabove.

According to another aspect of the invention, the hot gas path component is a transition duct.

The transition duct is generally one of the most critical components because the transition duct is exposed to the highest temperatures in the hot gas path. Thus, application of the present invention to transition ducts is particularly beneficial.

According to another aspect of the present invention, there is provided a gas turbine engine assembly comprising:

a compressor section extending along a main axis;

a plurality of can combustors circumferentially arranged about a main axis;

a turbine section;

wherein at least one of the can combustors comprises a hot gas wall member as defined hereinabove.

Drawings

The invention will now be described with reference to the accompanying drawings, which show some non-limiting embodiments of the invention, in which:

FIG. 1 is a side view of a gas turbine engine taken along an axial longitudinal plane;

FIG. 2 is a side view of a hot gas path of the gas turbine engine of FIG. 1;

FIG. 3 is a perspective view of a hot gas path component of the hot gas path of FIG. 2 in accordance with an embodiment of the present invention;

FIG. 4 is a rear view of the hot gas path component of FIG. 2;

FIG. 5 is a rear view of a detail of the hot gas path component of FIG. 2;

FIG. 6 is a perspective view of a hot gas path component according to another embodiment of the invention;

FIG. 7 is a perspective view of a hot gas path component according to another embodiment of the invention;

FIG. 8 is a rear view of a detail of a hot gas path component according to another embodiment of the invention;

FIG. 9 is a rear view of a detail of a hot gas path component according to another embodiment of the invention;

FIG. 10 is a rear view of a detail of a hot gas path component according to another embodiment of the invention; the method comprises the steps of,

FIG. 11 is a rear view of a detail of a hot gas path component according to another embodiment of the invention.

Detailed Description

FIG. 1 shows a simplified view of a gas turbine engine, indicated generally by the numeral 1. The gas turbine engine 1 comprises a compressor section 2, a combustor assembly 3 and a turbine section 5. The compressor section 2 and the turbine section 5 extend along a main axis a. The burner assembly 3 may be a sequential burner assembly as in the example of fig. 1, or a single stage burner assembly. In one embodiment, the burner assembly 3 comprises a plurality of sequential can-combustors 7 arranged circumferentially about the main axis a.

The compressor section 3 of the gas turbine engine 1 provides a compressed air flow which is added to the can-combustor 7 together with fuel and combusted in the can-combustor 7. For cooling purposes, the air flow delivered by the compressor section 2 is supplied to the combustor assembly 3 and to the turbine section 5.

Each of the can combustors 7 (one of which is shown in fig. 2) comprises first and

second stage combustors

8 and 9 and a transition duct 10, which are arranged sequentially and define a hot gas path 12.

More specifically, the first stage combustor 8 includes a first stage burner arrangement 14 and a first stage combustion chamber 15.

The second stage burner 9 is arranged downstream of the first stage burner 8 and comprises a second stage burner arrangement 17 and a second stage combustion chamber 18. Furthermore, the second stage combustor 9 is coupled to the turbine section 5 (not shown here) by a transition duct 10.

The second stage combustor 18 extends in the axial direction downstream of the first stage combustor 8. In one embodiment, second stage combustor 20 includes an outer liner 21 and an inner liner 22. The outer liner 21 surrounds the inner liner 22 at a distance from the inner liner 22 such that convective cooling channels 23 are defined between the outer liner 21 and the inner liner 22.

The transition duct 10 is shown in more detail in fig. 3 and 4, the transition duct 10 being the most severely thermally stressed component of the hot gas path 12. The transition duct 10 includes a plurality of cooling passages 27.

The tubular wall structure 25 has an upstream end 28, a downstream end 29, an inner surface 30, and an outer surface 31. The upstream end 28 is coupled to the second stage combustor 19, however, the downstream end 29 faces the turbine section 5. The inner surface 30 defines a hot gas flow space through which hot gas passes to the turbine section 5. Thus, the inner surface 30 is directly exposed to the hot gas flowing through the hot gas path 12.

The cooling channels 27 extend through the tubular wall structure 25 between the upstream end 28 and the downstream end 29 and are uniformly distributed along the circumferential direction of the tubular wall structure 25. At the upstream end 28, the cooling passages 27 are in fluid communication with the convective cooling passages 23 of the second stage combustion chamber 18. In one embodiment, the cooling channel 27 extends in the axial longitudinal direction of the tubular wall structure 25.

The cooling channels 27 also separate different parts of the tubular wall structure 25. As also shown in fig. 5, an interior portion 33 of the tubular wall structure 25 is defined between the interior surface 30 and the cooling passage 27 and has a first thickness T1 (i.e., the minimum distance between the interior surface 30 and the cooling passage 27). An outer portion 35 of the tubular wall structure 25 is defined between the outer surface 31 and the cooling channel 27 and has a second thickness T2. The second thickness T2 of the outer portion is greater than the first thickness T1 of the inner portion 33. Specifically, the second thickness T2 may be two to five times the first thickness T1.

The cooling channel 27 has a radial height H defined by the maximum radial distance across the cooling channel 27 between the inner portion 33 and the outer portion 35 of the tubular wall structure 25. The radial height H of the cooling channel is significantly greater than the first thickness T1 of the inner portion 33 of the tubular wall structure 25. The cooling channel 27 thus has a considerable cross section and allows a passage of a cooling air flow sufficient to avoid the cooling effect which may be severely affected by the heat extraction. In particular, the radial height H may be at least three and up to twenty times the first thickness T1 of the inner portion 33 of the tubular wall structure 25.

The radial height H is likewise greater than the width W of the cooling channel.

Adjacent cooling channels 27 are separated from each other by a membrane 37, the membrane 37 extending transversely to the inner portion 33 and the outer portion 35 of the tubular wall structure 25. In the embodiment of fig. 3-5, in particular, the membrane 37 is substantially perpendicular to the inner portion 33 and the outer portion 35 of the tubular wall structure 25. In this case, the membrane 37 has a uniform thickness and joins the inner portion 33 and the outer portion 35 of the tubular wall structure 25 by a smooth rounded transition. As a result, the cooling channel 27 has a substantially oval cross-section with substantially straight sides.

The cooling channels may have any suitable path between the upstream and downstream ends of the transition duct to provide the desired cooling effect. In the embodiment of fig. 6, for example, the transition duct has a tubular wall structure (denoted herein by numeral 125) with an upstream end 128, a downstream end 129, an inner surface 130, an outer surface 131, an inner portion 133, and an outer portion 135, substantially as already described. The cooling channel 127 (which likewise has an aspect ratio and dimensions as already described) extends along a spiral path about the longitudinal axis B of the tubular wall structure 125.

In one embodiment shown in fig. 7, transition duct 225 has a tubular wall structure 225 with an upstream end 228, a downstream end 229, an inner surface 230, an outer surface 231, an inner portion 233, and an outer portion 235 substantially as already described. The cooling passages 227 extend between the upstream end 228 and the downstream end 229 and are separated from one another by a diaphragm 237. The membrane 237 is discontinuous and interrupted by the notches 238, the notches 238 may be aligned in a substantially circumferential direction of the tubular wall structure 225 as in fig. 7, or otherwise staggered as desired in other embodiments not shown. The notch 238 of the diaphragm 238 helps to reduce mechanical stresses caused by thermal expansion.

In another embodiment of fig. 8, the transition duct has a tubular wall structure 325 with cooling channels 327 as already described, except that the cooling channels 327 are substantially rectangular in cross-section (possibly with rounded corners). The dissipating fins 340 extend longitudinally from the inner portion 333 of the tubular wall structure 325 along the cooling channel 327. In other embodiments (not shown), only some of the cooling channels may be provided with dissipating fins, according to specific requirements.

In the embodiment of fig. 9, the transition duct has a tubular wall structure 425 with cooling channels 427 separated from each other by diaphragms 437. The diaphragm 437 forms an angle α of between 30 ° and 90 ° with the inner 433 and outer 435 portions of the tubular wall structure 425. As a result, the cooling channels 427 have a cross-section in the form of a parallelogram.

Another embodiment is shown in fig. 10. In this case, the transition duct has a tubular wall structure 525 with cooling channels 527 separated from each other by a membrane 537. The septum 537 tapers from an outer portion 535 to an inner portion 533 of the tubular wall structure 525. As a result, the cooling channel 527 has a trapezoidal cross section with a wider base at the outer portion 535 of the tubular wall structure 525 and a smaller base at the inner portion 533 of the tubular wall structure 525.

In the embodiment of fig. 11, the transition duct has a tubular wall structure 625 with cooling channels 627 separated from each other by a diaphragm 637. The diaphragm 637 tapers from the inner portion 633 to the outer portion 635 of the tubular wall structure 625. Also in this case, the cooling channel has a trapezoidal cross section, but with the wider base at the inner portion 633 of the tubular wall structure 625 and the smaller base at the outer portion of the tubular wall structure 625.

Finally, it is obvious that modifications and variations can be made to the described transition duct without departing from the scope of the invention as defined in the appended claims.

In particular, any other component of the hot gas path may have the structure described above with a tubular wall structure and a relatively large cooling channel extending across the tubular wall structure. In one embodiment, not shown, for example, the second stage combustion chamber may have the same structure as the transition duct, with the cooling channels of the second stage combustion chamber being fluidly coupled to the corresponding cooling channels of the transition duct. The second stage combustion chamber and the transition duct may be formed in a single monolithic body.

Claims

1. A hot gas path component for a gas turbine engine, comprising:

a tubular wall structure (25,225,325,425,525,625) having an upstream end (28,228), a downstream end (29,229), an inner surface (30, 230) and an outer surface (31,231);

a plurality of cooling channels (27,227,327,427,527,627) extending through the tubular wall structure (25,225,325,425,525,625) between the upstream end (28,228) and the downstream end (29,229);

wherein an inner portion (33,233,333,433,533,633) of the tubular wall structure (25,225,325,425,525,625) defined between the inner surface (30, 230) and the cooling channel (27,227,327,427,527,627) has a first thickness (T1), and an outer portion (35,235,335,435,535,635) of the tubular wall structure (25,225,325,425,525,625) defined between the outer surface (31,231) and the cooling channel (27,227,327,427,527,627) has a second thickness (T2) that is greater than the first thickness (T1); and, in addition, the processing unit,

wherein the cooling channel (27,227,327,427,527,627) has a radial height (H) defined by a maximum radial distance across the cooling channel (27,227,327,427,527,627) between the inner portion (33,233,333,433,533,633) and the outer portion (35,235,335,435,535,635) of the tubular wall structure (25,225,325,425,525,625), and the radial height (H) of the cooling channel (27,227,327,427,527,627) is greater than the first thickness (T1) of the inner portion (33,233,333,433,533,633) of the tubular wall structure (25,225,325,425,525,625);

wherein adjacent cooling channels (27,227,327,427,527,627) are separated from each other by a diaphragm (37,237,337,437,537,637), the diaphragm (37,237,337,437,537,637) being transverse to the inner portion (33,233,333,433,533,633) and the outer portion (35,235,335,435,535,635) of the tubular wall structure (25,225,325,425,525,625);

wherein the membrane (237) is discontinuous and is interrupted by a gap (238).

2. The hot gas path component according to claim 1, wherein the second thickness (T2) is two to five times the first thickness (T1).

3. The hot gas path component according to claim 1, wherein the radial height (H) of the cooling channel (27,227,327,427,527,627) is at least three times the first thickness (T1) of the inner portion (33,233,333,433,533,633) of the tubular wall structure (25,225,325,425,525,625).

4. A hot gas path component according to any one of claims 1 to 3, characterized in that the radial height (H) is greater than the width (W) of the cooling channel (27,227,327,427,527,627).

5. The hot gas path component according to claim 1, wherein the diaphragm (37,237,337,437,537,637) is substantially perpendicular to the inner portion (33,233,333,533,633) and the outer portion (35,235,335,535,635) of the tubular wall structure (25,225,325,525,625), or the diaphragm (437) forms an angle between 30 ° and 90 ° with the inner portion (433) and the outer portion (435) of the tubular wall structure (425).

6. The hot gas path component according to claim 1 or 5, wherein the diaphragm (537,637) tapers from the inner portion (533,633) to the outer portion (535,635) of the tubular wall structure (525, 625) or from the outer portion (535,635) to the inner portion (533,633) of the tubular wall structure (525, 625).

7. A hot gas path component according to any one of claims 1 to 3, characterized in that the cooling channels (27,227,327,427,527,627) have a rectangular or parallelogram or trapezoid cross-section, or an oval cross-section, with rounded corners or without rounded corners.

8. The hot gas path component according to any one of claims 1 to 3, characterized in that the hot gas path component comprises at least one fin (340), the fin (340) extending longitudinally from the inner portion (333) of the tubular wall structure (325) along at least one of the cooling channels (327).

9. A hot gas path component according to any one of claims 1 to 3, wherein the cooling channels (27,227,327,427,527,627) are uniformly distributed along the circumferential direction of the tubular wall structure (25,225,325,425,525,625).

10. A hot gas path component according to any one of claims 1 to 3, characterized in that the cooling channels (27,227) extend along an axial longitudinal direction of the tubular wall structure (25) or along a spiral path around a longitudinal axis of the tubular wall structure (125).

11. A hot gas path assembly for a gas turbine engine comprising the hot gas path component according to any one of claims 1 to 10.

12. The hot gas path assembly of claim 11, wherein the hot gas path component is a transition duct.

13. A gas turbine engine, comprising:

-a compressor section (2) extending along a main axis (a);

-a plurality of can combustors (7) arranged circumferentially around the main axis (a);

a turbine section (5);

wherein at least one of the can combustors (7) comprises a hot gas path component according to any one of claims 1 to 10.