Combustor front panel

Abstract

A front panel for a combustor has a hot side and a cold side and at least one reception adapted for receiving a combustor part. The front panel has a double-wall design with a hot-side wall and a cold-side wall. The hot-side wall defines a hot-side downstream surface of the front panel. The cold-side wall defines a cold-side upstream surface of the front panel. The hot-side wall and the cold-side wall are axially spaced from one another, extend parallel to one another, and are connected to one another by an outer side wall.

Claims

1. A front panel for a combustor of a gas turbine, the front panel defining a hot side and a cold side and comprising: at least one aperture adapted for receiving a combustor part; a hot-side wall defining a hot-side downstream surface of the front panel; a cold-side wall defining a cold-side upstream surface of the front panel, wherein the hot-side wall and the cold-side wall are axially spaced from one another and extend parallel to one another; and an outer side wall connecting the hot-side wall and the cold-side wall, wherein each aperture of the at least one aperture is defined by a respective annular sleeve, wherein each respective annular sleeve extends from the hot-side wall to the cold-side wall, connects the hot-side wall and the cold-side wall to one another, and provides a seat for a respective combustor part, wherein an upstream portion of each respective annular sleeve has a material thickness that is 50% to 150% thicker than a material thickness of a downstream portion of the respective annular sleeve.

2. The front panel according to claim 1, wherein the hot-side wall and the outer side wall are made from one piece.

3. The front panel according to claim 1, wherein the hot-side wall is provided with a plurality of effusion passages, the effusion passages being through holes that extend substantially axially through the hot-side wall.

4. The front panel according to claim 1, wherein cooling passages are provided in the cold-side wall, the cooling passages being through holes that extend through the cold-side wall for controlling a fluid stream through the cold-side wall to the hot-side wall for cooling and frequency tuning purposes.

5. The front panel according to claim 1, wherein the outer side wall defines a circumference of the front panel.

6. The front panel according to claim 1, wherein a downstream end of the outer side wall is flush with the hot-side downstream surface.

7. The front panel according to claim 1, wherein a downstream end of the outer side wall comprises a radially protruding clamping ring and the outer side wall has a cross-section with a swan neck profile.

8. The front panel according to claim 7, wherein the radially protruding clamping ring has a lateral annular radius (r.sub.1) and an axial height (b.sub.1), wherein the lateral annular radius ranges from 2 millimeters to 25 millimeters and the axial height ranges from 2 millimeters to 25 millimeters.

9. The front panel according to claim 1, wherein the hot-side wall has a first material thickness (S.sub.1) and the cold-side wall has a second material thickness (S.sub.2), wherein the second material thickness is smaller than the first material thickness, wherein the first material thickness (S.sub.1) ranges from 1.5 millimeters to 28 millimeters, wherein the second material thickness (S.sub.2) ranges from 20% of the first material thickness (S.sub.1) to 80% of the first material thickness (S.sub.1).

10. The front panel according to claim 1, wherein the axial spacing between the hot-side wall and the cold-side wall, a first material thickness (S.sub.1) of the hot-side wall and a second material thickness (S.sub.2) of the cold-side wall, and a protrusion of the outer side wall beyond the cold-side upstream surface of the cold-side wall, are chosen so as to have a total axial height (h) of the front panel of 8 millimeters to 840 millimeters.

11. The front panel according to claim 1, wherein a cavity is defined between the hot-side wall, the cold-side wall, and the outer side wall of the front panel, wherein an axial height (h.sub.p) of the cavity ranges from 1.5S.sub.1 to (h(S.sub.1+S.sub.2)), wherein S.sub.1 is a material thickness of the hot-side wall, S.sub.2 is a material thickness of the cold-side wall, and h is a total axial height of the front panel.

12. A front panel for a combustor of a gas turbine, the front panel defining a hot side and a cold side and comprising: at least one aperture adapted for receiving a combustor part; a hot-side wall defining a hot-side downstream surface of the front panel; a cold-side wall defining a cold-side upstream surface of the front panel, wherein the hot-side wall and the cold-side wall are axially spaced from one another and extend parallel to one another; and an outer side wall connecting the hot-side wall and the cold-side wall, wherein the hot-side wall has a first material thickness (S.sub.1) and the cold-side wall has a second material thickness (S.sub.2), wherein the second material thickness is smaller than the first material thickness.

13. The front panel according to claim 1, wherein the outer side wall has at least one first intermediate portion, wherein said at least one first intermediate portion comprises: a material thickness that is smaller than a material thickness of a second portion of the outer side wall, and/or is laterally shifted with respect to the second portion of the outer side wall.

14. The front panel according to claim 13, wherein the material thickness of the at least one first intermediate portion of the outer side wall is 50% to 80% of the material thickness of the second portion of the outer side wall, and/or wherein a lateral shift of the at least one first intermediate portion of the outer side wall with respect to the second portion of the outer side wall is 30% to 100% of the material thickness of the second portion.

15. A combustor arrangement for a gas turbine comprising: the front panel according to claim 1.

16. The front panel according to claim 1, wherein the hot-side wall, the outer side wall, and the cold-side wall are made from one piece.

17. The front panel according to claim 1, wherein an upstream end of the outer side wall axially protrudes beyond the cold-side upstream surface of the cold-side wall.

18. A front panel for a combustor of a gas turbine, the front panel defining a hot side and a cold side and comprising: at least one aperture adapted for receiving a combustor part; a hot-side wall defining a hot-side downstream surface of the front panel; a cold-side wall defining a cold-side upstream surface of the front panel, wherein the hot-side wall and the cold-side wall are axially spaced from one another and extend parallel to one another; an outer side wall connecting the hot-side wall and the cold-side wall; and a radially protruding clamping ring provided on a downstream end of the outer side wall, wherein the radially protruding clamping ring has a lateral annular radius (r.sub.1) and an axial height (b.sub.1), wherein the lateral annular radius ranges from 2 millimeters to 25 millimeters and the axial height ranges from 2 millimeters to 25 millimeters.

19. The front panel according to claim 12, wherein each aperture of the at least one aperture is defined by a respective annular sleeve, wherein each respective annular sleeve extends from the hot-side wall to the cold-side wall, connects the hot-side wall and the cold-side wall to one another, and provides a seat for a respective combustor part.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Preferred embodiments of the invention are described in the following with reference to the drawings, which are for the purpose of illustrating the present preferred embodiments of the invention and not for the purpose of limiting the same. In the drawings,

(2) FIG. 1 shows a cross-section view of a front panel according to a first embodiment of the present invention;

(3) FIG. 2 shows a top-view of the front panel according to FIG. 1;

(4) FIG. 3 shows an enlarged cross-section view of a radially outer side wall of the front panel according to FIG. 1;

(5) FIG. 4 shows an enlarged cross-section view of a second embodiment of the present invention with a differently structured radially outer side wall;

(6) FIG. 5 shows an enlarged cross-section view of a third embodiment of the present invention with a yet a further differently structured radially outer side wall; and

(7) FIG. 6 shows a cross-section view of a front panel according to a first embodiment of the present invention.

DETAILED DESCRIPTION

(8) FIG. 1 shows a cross-section view of a front panel 1 according to a first embodiment of the present invention. The cross-section is along a diameter D1 of the generally circularly shaped, plate-like front panel 1. FIG. 2 shows the front panel 1 according to FIG. 1 in a top view from the cold side 13. The first embodiment according to FIGS. 1, 2 is now described in detail.

(9) The front panel 1 defines a hot side 12 and the cold side 13. The front panel 1 has a double-wall design and comprises a hot-side wall 2 (first wall) and a cold-side wall 3 (second wall). The hot-side wall 2 has an upstream surface 21 and a downstream surface 22 (see FIG. 3). The cold-side wall 3 has an upstream surface 31 and a downstream surface 32 (see FIG. 4). The upstream surface 21 of the hot-side wall 2 faces the cold-side wall 3; the downstream surface 22 of the hot-side wall 2 is on the hot side 12 of the front panel 1. The upstream surface 31 of the cold-side wall 3 is on the cold side 13 of the front panel 1; the downstream surface 32 of the cold-side wall 3 faces the hot-side wall 2. On the cold side 13, fluids are supplied to the front panel 1, e.g. oxidizer and fuel mixing and supplying may be done. The fluids are then guided through the front panel 1, from the cold side 13 to the hot side 12, i.e. to the flame side, where the fuel mixture is burned in a combustion zone, the latter being defined downstream of the hot-side wall 2. From the combustion zone the compressed hot working fluid is guided to the turbine and expanded under production of kinetic energy.

(10) The hot-side wall 2 and the cold-side wall 3 are substantially circular walls and define the lateral diameter D1 of the substantially circular front panel 1. The walls 2, 3 are arranged at an axial distance to one another, i.e. spaced relative to one another to create the double-wall structure. The walls 2, 3 extend generally parallel to one another, while having substantially the same lateral dimensions, in particular the same diameter D1. The cold-side wall 3 preferably has a smaller material thickness than the hot-side wall 2. In particular embodiments, the walls 2, 3 may have any shape.

(11) The hot-side wall 2 and the cold-side wall 3 are connected to one another by a radially outer side wall 4. The outer side wall 4 extends generally axially and circumferentially around both the hot-side wall 2 and the cold-side wall 3.

(12) The front panel 1 comprises a plurality of apertures 7 to 10, each for receiving a combustor part such as a burner, mixer, or igniter element. In some embodiments, there is provided one, two, three, five, six, or more apertures 7 to 10. In the embodiment according to FIGS. 1 and 2, four apertures 7 to 10 are provided in the front panel 1. Each aperture 7 to 10 is provided in a quarter sector of the front panel 1 and includes a rim element for seating and sealing the particular combustor part. Furthermore, each aperture 7 to 10 comprises a passage for conveying fluids provided on the cold side 13 through the combustor part from the cold side 13 to the hot side 12 of the front panel 1.

(13) Side walls of the apertures 7 to 10 are provided by annular sleeves 70, 80, 90, 100, the latter extending generally axially through the front panel 1, from the cold side 13 to the hot side 12. The annular sleeves 70, 80, 90, 100 are fixed to openings in both the hot- and cold-side wall 2, 3, thereby connecting the latter to one another and further supporting the double-wall structure. The annular sleeves 70, 80, 90, 100 limit the apertures 7, 8, 9, 10 in radial and axial directions. The annular sleeves 70, 80, 90, 100 have a generally right circular cylinder shape. They provide a passage for combustor parts such as burner units or the like for introduction of fluids in to the combustion chamber on the hot side 12. In FIG. 2, one can see, from the cold side 13 to the hot side 12, through the passages of apertures 7 to 10. The annular sleeves 70, 80, 90, 100 connect the hot-side wall 2 and the cold-side wall 3 to one another and therefore enhance the mechanical stability of the front panel 1. At an upstream periphery edge of each the sleeves 70, 80, 90, 100 is provided a tapered portion 71, 81, 91, 101 that protrudes substantially perpendicularly over the upstream surface 31 of the cold-side wall 3. The tapered protrusions 71, 81, 91, 101 have each a slanted surface, the latter facing the respective apertures 7 to 10, and a substantially axially oriented surface opposite of the slanted surface. The tapered protrusions 71, 81, 91, 101 run circumferentially around the respective aperture 7, 8, 9, or 10. The slanted periphery edge of portions 71, 81, 91, 101 serve for easy insertion (e.g. optimized guidance) and optimal seating of the received combustor part (not shown). In addition a height of the respective aperture 7, 8, 9, or 10 can have a variation to ease the assembly, for example a variation in height of between 3 and 10 mm, or preferably around 6 mm.

(14) Additionally, in some embodiments, the upstream section of the annular sleeves 70, 80, 90, 100, 110 may be reinforced or have an enhanced material thickness. Accordingly, the annular sleeves 70, 80, 90, 100 of the apertures 7 to 10 may have their upstream section (upper third to upper forth of the entire axial extension) provided as a reinforced section 72, 82, 92, 102 with a material thickness that is 50% to 150%, preferably about 100%, thicker than a material thickness of the downstream section of the sleeves 70, 80, 90, 100. A transition section from the downstream section to the thicker upstream section 72, 82, 92, 102 of the sleeve 70, 80, 90, 100 may be a flat ramp or a rounded transition section.

(15) In front panel 1, a further central passage 11 may be arranged (see below). The further passage 11 may also have an annular sleeve 110 with a reinforced upstream section 112. Said reinforced upstream section 112 may be arranged in a region where the cold-side wall 3 laterally joins the sleeve 110 (see FIG. 1).

(16) Typical diameters of the apertures 7, 8, 9, 10 range from 50 millimeters to 1000 millimeters depending on the designated combustor part and the number of units to be received by the front panel 1.

(17) A cavity 6 is defined between the hot-side wall 2, the cold-side wall 3, the outer side wall 4, and the annular sleeves 70, 80, 90, 100, 110. This cavity 6 has an axial height h.sub.p, which corresponds to the axial distance between the upstream surface 21 of the hot-side wall 2 and the downstream surface 31 of the cold-side wall 3. The cavity 6 serves as an insulation volume. The distance h.sub.p between the walls 2, 3, or in other words the cavity 6, helps in enhancing a mechanical stability of the front panel 1, in particular by increasing an area momentum of inertia of the front panel 1 (in cross-sectional view according to FIGS. 1, 3 to 5).

(18) The cold-side wall 3 acts as a stiffener plate that helps to mechanically stabilize the front panel 1 and, at the same time, to tune the natural frequencies of the front panel 1 such that its natural frequencies are preferably above a certain limit. The cold-side wall 3 extends parallel to the hot-side wall 2 and connects the outer side wall 4 with the mixer-rim pieces, i.e. with the annular sleeves 70, 80, 90, 100, 110. Moreover, the cold-side wall 3 is perforated with holes 14, 15 and cut-outs 16 for conveying cooling air to the hot-side wall 2 (in particular for passage through the effusion holes 23, see FIG. 4) and for frequency tuning (see FIG. 2).

(19) Accordingly, in the cold-side wall 3 are provided a plurality of fluid passages 14, 15. These fluid passages 14, 15, 16 are passages for a cooling fluid, e.g. air. Some of the cooling passages 14, 15 may have a generally circular shape. Some of the generally circular cooling passages 14, 15, i.e. the small cooling passages 15, have a small diameter (e.g. 5 millimeters to 15 millimeters), while others, i.e. the medium cooling passages 14, have a larger diameter (e.g. 10 millimeters to 30 millimeters). Yet other cooling passages 16 may have a different shape than generally circular and may be quite larger. The large cooling passages 16 with different shape may be cut-outs that dominate the frequency tuning property of the front panel 1. In the embodiment according to FIG. 2, the cut-outs 16 have a substantially triangular shape, while the hypotenuse-like section of the triangle is a circular sector of the outer edge of the circular cold-side wall 3. It is to be understood that the number, shape, and arrangement of the cooling passages 14, 15, 16 in cold-side wall 3 may be of any shape or size, depending on the actual combustor requirements.

(20) The fluid passages 14, 15, 16 extend from the upstream surface 31 of the cold-side wall 3 to its downstream surface 32 and thereby fluidly connect the cold side 13 and the cavity 6 to one another. Accordingly, the cooling passages 14, 15, 16 provide the cooling fluid to effusion passages 23, the latter being provided in the hot-side wall 2 (see FIG. 4).

(21) Moreover, in a center of the front panel 1, a further central passage 11 is provided. As can be seen in FIG. 1, unlike the cooling passages 14 to 16 that only extend into cavity 6, the further passage 11 (like the passages of the apertures 70, 80, 90, 100) extends from the cold side 13 to the hot side 12. The passage 11 is therefore a through-hole through the front panel 1. It is defined by a central hole in both walls 2, 3 which are connected by the further annular sleeve 110, which connects the center part of the cold-side wall 3 and the hot-side wall 2. A diameter of the further passage may be the same as the diameter of the medium cooling passage 15. An upstream end of the annular sleeve 110 may be slanted like the other annular sleeves 70, 80, 90, 100, the slanted surface facing the center of the front panel 1.

(22) The hot-side wall 2 and the outer side wall 4, and preferably the cold-side wall 3, may be cast and/or machined from one piece. The annular sleeves 70, 80, 90, 100, 110 may be welded or attached to the walls 2-4.

(23) FIGS. 3 to 5 show preferred embodiments of the front panel 1 according to invention. In particular, FIGS. 3 to 5 show, in a cross-sectional view, differently structured outer side walls 4.

(24) A total height h of the front panel 1 may be 4% to 40% of a diameter D1 of the circular front panel 1.

(25) The diameter D1 of the front panel 1 may be 198 millimeters to 2100 millimeters.

(26) A thickness S.sub.1 of the hot-side wall 2 may be 1/75 to 1/125 of D1. The thickness of S.sub.1 depends on the cooling requirement. It can be designed for effusion cooling, which typically requires a minimum S.sub.1 ranging from 4 millimeters to 15 millimeters. Preferably, S.sub.1 is about or exactly 6 millimeters thick.

(27) A thickness S.sub.2 of the cold-side wall 3 may typically be small compared to the thickness S.sub.1 of the hot-side wall 2 for elasticity. Preferably, S.sub.2 ranges from 20% of S.sub.1 to 80% of S.sub.1.

(28) The outer side wall 4 has a downstream portion 41 and an upstream portion 43. The upstream portion 43 includes a free end with a radially outwardly protruding clamping ring 5. The clamping ring 5 is circumferentially surrounding the front panel 1 and serves for fastening of the front panel 1 in a combustor arrangement. The clamping ring 5 has a material thickness or height b.sub.1 in axial direction (see FIG. 5). This axial height b.sub.1 may be 2 millimeters to 25 millimeters. A radial width r.sub.1 of the annulus of 5, i.e. the annular radius, may be 2 millimeters to 25 millimeters wide. A radially inner periphery edge 50 of the clamping ring 5 may be slanted (see FIG. 4). The clamping ring 5 is configured for being clamped by further combustor part. The clamping ring 5 may be clamped between a carrier structure and a combustion liner of a gas turbine. The clamping ring 5 according to FIGS. 1 to 5 is oriented radially outwardly. In other embodiments, the clamping ring 5 may be oriented radially inwardly.

(29) Downstream of the downstream portion 41 of the outer side wall 4 joins a first transition portion 40 which connects the outer side wall 4 to the hot-side wall 2. The first transition portion 40 is rounded with an osculating circle having a radius of the material thickness of the hot-side plate 2. This radius may also be 10% to 300% or more of said material thickness. Along the first transition portion 40 the orientation of the outer side wall 4 of the front panel 1 changes its orientation from radial to axial. The first transition portion 40 therefore matches the hot-side wall 2 and the outer side wall 4 in orientation and thickness. The change in orientation is done within 10% to 20% of the total height h of the front panel 1 (see FIG. 4).

(30) The outer side wall 4 may be structured such that the mechanical, fluid-mechanical, and thermal properties of the front panel 1 are improved. Therefore, a second transition portion 42 may be provided between the upstream and the downstream portion 41, 43. This second transition portion 42 connects the upstream and the downstream portion 41, 43. In some embodiments, the upstream portion 43 may have a thinner material thickness than the downstream portion 41, e.g. the upstream portion 43 may have a material thickness that is 50% to 90% of the material thickness of the downstream portion 41. The transition section 42 may be a ramp or a rounded section that connects the two differently dimensioned sections. The adjustment of the material thickness in the transition portion 42 may be done on the inside (facing the cavity 6, see FIG. 3) or it may be done on the outside, or it may be done on both sides (see FIG. 4). In some embodiments, the transition portion 42 may also or additionally be a kink (see FIG. 5). Here, the downstream portion 41 is shifted laterally with respect to the upstream portion 43; accordingly, the upstream and downstream portions 41, 43 are no longer axially aligned. Moreover, the outer side wall 4 may be undulating or of any other laterally displacing shape. In preferred embodiments, both the material thickness and a kink structure may be present in the outer side wall 4 (see FIG. 5). This structuring of the outer side wall 4 enhances the mechanical stability of the front panel 1.

(31) The axial height h.sub.p of the cavity 6 ranges between 1.5S.sub.1 and (h(S.sub.1+S.sub.2)). The axial height h.sub.p is constant over the front panel 1 and decreases in the radial outer part as the first transition section 40 guides the outer wall of the front panel 1 into axial direction.

(32) FIG. 3 shows the embodiment according to FIGS. 1 and 2. The downstream portion 41 has the same material thickness as the hot-side wall 2, i.e. S.sub.1. The second transition portion 42 tapers from the inside to match the material thickness of the upstream portion 43, the latter being about 50% of the material thickness of the downstream portion 41. The transition portion 42 is arranged in the upper half of the cavity 6 and has a height in axial direction of about S.sub.1. A height of a portion of the cavity 6 associated with the upstream portion 43 is about half of a height of a portion of the cavity 6 associated with the downstream portion 41. The total height of the cavity 6 is h.sub.p.

(33) FIG. 4 shows an embodiment with a transition portion 42 that is tapering on both the inner and the outer surface of the outer side wall 4 so as to match the downstream portion 41 to the upstream portion 43. As can be seen, the transition portion in 42 extends over more than the upper half of the cavity 6 and continues axially upstream to the cold-side wall 3.

(34) FIG. 5 shows a further embodiment where the transition portion 42 is arranged in the upper half of the cavity 6 and has a height in axial direction of about S.sub.1, as the embodiment in FIG. 3. The downstream portion 41 has the same material thickness as the hot-side wall 2, i.e. S.sub.1. The upstream portion 43 has a material thickness that is about 75% of S.sub.1. The transition portion 42 is shaped to cause a shift of the upstream portion 43 relative to the downstream portion 41 into the cavity 6 by about 30% to 50% of S.sub.1. Accordingly, the outer side wall 4 in the embodiment according to FIG. 5 has a kink.

(35) The herein described embodiments of the invention are given by way of example and explanation and do not limit the invention. To someone skilled in the art it will be apparent that modifications and variations may be made to these embodiments without departing from the scope of the present invention. In particular, features described in the context of one embodiment may be used on other embodiments. The present invention therefore covers embodiments with such modifications and variations as come within the scope of the claims and also the corresponding equivalents.