BURNER ASSEMBLY FOR A BURNER OF A GAS TURBINE

Abstract

A burner assembly of a gas turbine comprising: a tubular body defining the flow path for the hot gas of the combustion during the turbine operation; an aperture for a fuel lance; a wearing ring of a sacrificial material configured to correspond to the edge of the aperture; a contacting leg extending from the wearing ring on the tubular body; a pre-tension system configured to contact the contacting leg in order to provide a pre-tension force on the ring.

Claims

1. A burner assembly of a gas turbine comprising: a tubular body defining the flow path for a hot gas of combustion during the turbine operation; an aperture for a fuel lance having an edge; a wearing ring, of a sacrificial material, configured to correspond to the edge of the aperture; a contacting leg extending from the wearing ring along said tubular body; a pre-tension system configured to contact the contacting leg to provide a pre-tension force on the ring against the tubular body.

2. The burner assembly according to claim 1, where said wearing ring comprises two contacting legs extending in opposite directions and substantially parallel to the hot gas flow path, and a pre-tension system for each of said extending legs.

3. The burner assembly according to claim 1, wherein said pre-tension system comprises a pre-tension block anchored on said tubular body in such a way to form a gap through which said contacting leg is positioned.

4. The burner assembly according to claim 3, wherein said pre-tension block comprises a pre-tension surface arranged to contact the contacting leg to provide said pre-tension force.

5. The burner assembly according to claim 4, wherein a first intermediate element is located between the pre-tension block and said contacting leg.

6. The burner assembly according to claim 3, wherein said pre-tension block comprises a pre-tension component configured to contact said contacting leg to provide said pre-tension force.

7. The burner assembly according to claim 6, wherein said pre-tension component is a pre-tension bolt screwed into said pre-tension block and wherein a locking element is additionally mounted into said pre-tension block; said pre-tension bolt comprising a shaped head able to engage with said locking element.

8. A wearing ring (15) comprising a contacting leg according to claim 1.

9. A gas turbine comprising a burner assembly according to claim 1.

10. A method for installing a fuel lance in a burner assembly of a gas turbine comprising the following steps: providing a tubular body of the burner assembly defining a hot gas flow path during the turbine operation; providing an aperture on the tubular body for positioning a fuel lance in the hot gas flow path; associating a wearing ring of a sacrificial material to the edges of the aperture; said ring comprising a contacting leg extending along the tubular body; associating a pre-tension system on the tubular body; said system being configured to contact said contacting leg so as r to provide a pre-tension force on the ring; and placing a fuel lance inside said aperture to lay on said wearing ring.

11. The method according to claim 10, wherein said step d) further comprising: providing a pre-tension block having a pre-tension surface arranged to contact the at least one contacting leg (15A; 15B) in such a way to form a gap with the tubular body.

12. The method according to claim 11, further comprising: adjusting the tolerances between the pre-tension surface and the tubular body to contact said leg (15A, 15B) and to provide the pre-tension force on said leg.

13. The method according to claim 11, further comprising: providing a pre-tension element in the pre-tension blocks configured to contact the respective leg so as to adjust the pre-tension force.

14. The method according to claim 13, further comprising: screwing the pre-tension bolt, comprising the shaped head, into the pre-tension block to provide the desired pre-tension force on the contacting legs; mounting the locking element into the pre-tension block and engage with the shaped head to prevent rotation of the bolt.

15. The method according to claim 14, further comprising: providing a plurality of locking positions of the locking element over a circumference around the shaped head so by reducing the incremental step size of the adjustment, thereby increasing the possible adjustment precision and regulating the pre-tension force.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The aspects and other features of the present invention will become more apparent upon reading of the following non-restrictive description of embodiments thereof, given for the purpose of exemplification only, with reference to the accompany drawings, through which similar reference numerals are used to refer to similar elements, and in which:

[0049] FIG. 1 shows a sequential combustion gas turbine of the prior art;

[0050] FIG. 2 shows a wearing ring according an embodiment of the present disclosure;

[0051] FIG. 3 shows a burner assembly according a first embodiment of the disclosure;

[0052] FIG. 4 shows a vertical cross-section of FIG. 3 with a Fuel lance and a sensor;

[0053] FIG. 5 shows a burner assembly according a second embodiment of the disclosure;

[0054] FIG. 6 shows a burner assembly according a third embodiment of the disclosure;

[0055] FIG. 7 shows an expanded view of a detail of FIG. 6;

[0056] FIG. 8 shows a cross-section according A-A of FIG. 7;

[0057] FIG. 9 shows a pre-tension bolt according the embodiment of FIG. 6;

[0058] FIG. 10 shows possible positions of the pre-tension bolt according the embodiment of FIG. 6;

[0059] FIG. 11 shows different embodiments of the pre-tension bolt.

[0060] Exemplary embodiments will be now described with reference to the aforementioned drawings.

DETAILED DESCRIPTION OF THE INVENTION

[0061] FIG. 2 shows a wearing ring (15) according to the present embodiments.

[0062] The wearing ring (15) comprises two contacting legs (15A, 15B) extending in opposite directions protruding from a circular section (15C).

[0063] The circular section (15C) has a protruded rim (15D) and its geometry is configured to come into contact with the edge (4E) of an aperture (4) of a burner (9), see FIGS. 3 to 6.

[0064] The ring (15) is made an embodiment by a sacrificial alloy, such as a nickel-based alloy, such as HAYNES188.

[0065] A sacrificial alloy can be an alloy softer than the material of the surrounding components.

[0066] For example, the sacrificial alloy of the ring is softer than the alloy of the fuel lance, if the lance is made with alloy.

[0067] The legs (15A, 15B) can vary in number and position and are here represented only as one solution.

[0068] FIG. 3 shows a burner assembly (9) comprising a tubular body (9A) defining the hot gas flow path (arrow G) in substantial axial direction.

[0069] The hot gas flow (G) enters the burner assembly (9) from the high pressure turbine (not shown) and exits from the burner assembly (9) entering in the combustion chamber (10).

[0070] The assembly (9) also comprises an aperture (4) inside which a fuel lance (not shown) can be placed. The assembly further comprises a pair of pre-tension systems (19; 21).

[0071] In an embodiment, each pre-tension system (19; 21) comprises a pre-tension block (19A; 21A) anchored on the tubular body (9A) in such a way as to form a gap (P) with the body (9A) itself.

[0072] Different anchoring means (9H; 9K) can be provided to associate the block (19A; 21A) to the tubular body (9A), for example bolts, pins or shaped fastenings.

[0073] These blocks (19A; 21A) are already included in the design of a standard burner; however, it is not to be excluded to provide blocks with different geometry or position according specific needs.

[0074] The circular section (15C) of the ring (15) is associated and corresponds to the aperture (4); its legs (15A, 15B) extending inside the respective gap (P) in a substantially parallel direction in respect to the hot gas flow path (G).

[0075] In another embodiment of the invention, the pre-tension block (19A; 21A) comprises a shim or a pills to contact the leg (15A, 15B).

[0076] FIG. 4 shows a vertical cross-section of one of the blocks (19) of FIG. 3.

[0077] FIG. 4 also shows a fuel lance (13) placed in the aperture (4) that is aligned with the hot gas flow path (G). A sensor (16) is place in proximity to the lance (13) to monitor the combustion conditions.

[0078] In an embodiment the sensor (16) is a thermocouple used to control the operation of the combustion of the engine.

[0079] The ring (15) is place on the aperture (4) so that its circular section (15C) comes into contact with a protruded edge (4E) of the aperture (4).

[0080] Clearances of some millimetres (not shown) may be provided between the fuel lance (13) and the ring (15) in order to allow an easy assembly.

[0081] Each pre-tension block (19A; 21A) comprises a pre-tension surface (19S; 21S) arranged so as to contact the leg (15A, 15B) and to provide the pre-tension force (F) on the leg (15A, 15B) in order to block the ring (15) on the edge (4E) of the aperture (4). The manufacturing tolerances between the pre-tension surface (19S; 21S) and the tubular body (9A) are adjusted for this purpose.

[0082] The gap (P) is therefore formed between the pre-tension surface (19S; 21S) and the tubular body (9A).

[0083] The pre-tension force (F) acts in a substantial radial direction in respect to a hot gas path (G).

[0084] In another embodiment, a first intermediate element (19E, 21E) is located between the block (19A; 21B) and the leg (15A, 15B). The first intermediate element (19E, 21E) may be configured as a hook, a holder, a seal, or a coating.

[0085] FIG. 5 shows a burner assembly (90) comprising a couple of pre-tension systems (119; 121) that each comprise a pre-tension block (119A; 121A) similar to the blocks (19A; 21A), with a pre-tension element (119T; 121T) placed in a respective block (119A; 121A).

[0086] These pre-tension elements (119T; 121T) are in the form of springs or bellows and configured to contact the respective leg (15A, 15B) in order to adjust the pre-tension force (F).

[0087] In this way, the manufacturing tolerances of the gap (P)as described in reference to FIGS. 3 and 4does not need to be adjusted.

[0088] FIG. 6 shows a burner assembly (900) comprising a couple of pre-tension systems (219; 221), each of them further comprising a pre-tension block (219A; 221A) similar to the blocks (19A, 21A; 119A, 121A) of the previous embodiments, with the pre-tension element (119T; 121T) described in reference of FIG. 5 now made by a pre-tension bolt (219T; 221T) screwed on the respective block (219A; 221A).

[0089] Each of these pre-tension bolts (219T; 221T) is configured to contact the respective leg (15A, 15B) in order to adjust the pre-tension force (F).

[0090] In this embodiment, the manufacturing tolerances of the gap (P) do not need to be very accurate.

[0091] In an embodiment of the invention, a locking element (219L; 221L) is screwed into each of the pre-tension blocks (219A; 221A) and the bolt (219T; 221T) comprises shaped heads (219H; 221H) able to engage with the respective locking element (219L; 221L), see also FIGS. 7 and 8.

[0092] The locking element (219L; 221L) can be a bolt, a pin, a bolt with inner hex head or similar structure.

[0093] The bolt (219T; 221T) is able to change its relative position in respect to the locking element (219L; 221L) with the counter-hole by turning, in order to allow adjustment of the pre-tension force (F).

[0094] FIG. 7 is a cross-section of the pre-tension block (219A) where it is possible to see, in particular, the bolt (219T) contacting and providing the pre-tension force (F) on the leg (15B) and, also, the protruded rim (15D) and the circular section (15C) contacting the edge (4E) of the aperture (4).

[0095] FIG. 8 is a section according A-A of FIG. 7 where it is possible to see, in particular, the shaped head (219H) engaging with the locking element (219L) screwed in the block (219A), in order to avoid the rotation of the bolt (219T) after installation or during operation; the bolt (219T) contacts and provides the pre-tension force (F) on the leg (15B).

[0096] In an embodiment, a second intermediate element (219E) is located between the bolt (219T; 221T) and the leg (15A, 15B), such as a wear resistant coating, a wear resistant shims, a pressure homogenizing joint such as a spherical joint or others.

[0097] FIG. 9 shows a view of the pre-tensioning bolt (219T) with a threated portion (219P) and the shaped head (219H) comprising screwing elements (219D), for example double-holes for a pin-wrench or additional hex head or inner hex-socket or similar, to easily allow the screwing of the bolt (219T) into the block (219A).

[0098] In an embodiment shown in FIG. 9, the shaped head (219H) comprises circular segments (219F) configured to match with the shape of the locking element (219L) in order to prevent the rotation of the bolt (219T).

[0099] FIG. 10 shows a top view of the assembly composed by the bolt (219T) and the locking element (219L) in a locking position (solid line) and in additional two possible locking positions (dotted lines) provided over a circumference by a defined pitch-ratio between the locking element (219L) and shaped head (219H) in order to reduce the incremental step size of the adjustment, thus increasing the possible adjustment precision and regulating the pre-tension force (F).

[0100] In FIG. 11, the pre-tension bolt (219T) is shown according other possible alternatives (319T; 419T; 519T; 619T).

[0101] According to another aspect a method for installing the fuel lance (13) in the burner assembly (9; 90; 900) comprising the following steps: provide a tubular body (9A) of the burner assembly (9; 90; 900) defining a hot gas flow path (G) during the turbine operation; provide an aperture (4) on the tubular body (9A) for positioning a Fuel lance (13) in the hot gas flow path (G); associate a wearing ring (15) of a sacrificial material to the edges (4E) of the aperture (4); said ring (15) comprising a leg (15A; 15B) extending along the tubular body (9A); associate a pre-tension system (19, 21; 119, 121; 219, 221) on the tubular body (9A); said system (19, 21; 119, 121; 219, 221) configured to contact said leg (15A, 15B) in order to provide a pre-tension force (F) on the ring (15); place the fuel lance (13) inside the aperture (4) so as to lie on the wearing ring (15).

[0102] According to an embodiment, the above mentioned step d) further comprises the following sub-step d1): providing a pre-tension block (19A, 21A; 119A, 221A; 219A, 221A) having a pre-tension surface (19S; 21S) arranged to contact the contacting leg (15A; 15B) in such a way to form a gap (P) with the tubular body (9A);

[0103] The sub-step d1) further comprises: adjusting the manufacturing tolerances between the pre-tension surface (19S; 21S) and the tubular body (9A) so as to contact and to provide the pre-tension force (F) on the leg (15A, 15B).

[0104] According to an alternative embodiment, the above sub-step dl) comprises: providing a pre-tension element (119T, 121T; 219T, 221T) in the pre-tension block (119A, 121A; 219A, 221A) configured to contact the leg (15A, 15B) in order to provide the pre-tension force (F).

[0105] This last sub-step may further comprise: providing a pre-tension bolt (219T; 221T) comprising a shaped head (219H; 221H) in the pre-tension block (219A; 221A) such as to provide the desired pre-tension force (F) on the legs (15A, 15B); screwing a locking element (219L; 221L) on the pre-tension block (219A; 221A) such as to engage with the shaped head (219H; 221H) to avoid any possible rotation of the pre-tension bolt (219T; 221T).

[0106] An additional step may include providing a plurality of locking positions of the locking element (219L; 221L) over a circumference around the shaped head (219H; 221H) in order to reduce the incremental step size of the adjustment, thus increasing the possible adjustment precision and regulating the pre-tension force (F).

[0107] While described in detail in connection with a sequential combustion gas turbine, embodiments may be applied to other types of gas turbine; the present invention being not limited to such sequential combustion gas turbine.

[0108] Additionally, only a limited number of embodiments have been described in the detailed description, it should be readily understood that the present description is not limited to such disclosed embodiments. Rather, the description can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described. Additionally, while various embodiments have been described, it is to be understood that aspects may include only some of the described embodiments. Accordingly, the specification and claimed embodiments are not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.

[0109] This written description uses examples to disclose the invention, including the preferred embodiments, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.