Improved burner part, and burner having a burner part of this kind

Abstract

The invention relates to a burner part (11) for use in a burner (1) located inside a flow channel (2) with a flow direction, the burner part having an upstream front edge (12), a downstream rear edge (13), and a component wall (14) which extends from the front edge (12) to the rear edge (13) and in a transverse direction transversely to the flow direction from a first wall end (15) to an opposing second wall end (16), the burner part comprising two stages (40, 43) for a combustion process, wherein the two stages (40, 43) are supplied via a common cavity (83).

Description

[0001] Improved burner part and burner with such

[0002] Burner part

[0003] The invention relates to a burner part for use in a burner.

[0004] In newer versions of gas turbines, higher turbine inlet temperatures and higher temperatures in the combustion zone (TiTiso; TPZ) and an increasing mass flow rate are achieved while simultaneously reducing NOx emissions. For this purpose, a modified and improved burner section for the main burner was developed, successfully tested, and deployed.

[0005] In order to remain competitive with machines already in use, these targets must also be met.

[0006] However, this new burner type is only available in a four-stage variant, which cannot be used or replaced economically in service machines due to a two-stage variant ("pilot" and "main burner").

[0007] For effective combustion with the aim of avoiding pollutants as far as possible, it is essential that the fuel is homogeneously mixed with the combustion air before combustion. To achieve this, various solutions are used in the state of the art. In many cases these are based on creating turbulence between the combustion air and the fuel. Although turbulence leads to resistance in the flow, it is generally not possible to achieve the desired largely pollutant-free combustion without turbulence. In order to mix the combustion air with the fuel, flow elements are usually arranged in the flow path to deflect the flow and create turbulence. In many cases, vane-like structures are used for this purpose.DE 10 2014 207 428 A1 discloses a three-stage burner in which a series of openings are formed via an access on the suction and pressure side of the swirl vane, thereby forming two stages.

[0008] Furthermore, it is known to arrange disruptive contours on the surface along the flow path, which cause turbulence in the combustion air. For example, it is known to arrange so-called vortex generators on the wall of a flow channel, which extend into the flow channel.

[0009] It is therefore the object of the present invention to achieve reduced NOx emissions in existing plants.

[0010] The object of the invention is therefore to improve the burner part in order to achieve a reduction in NOx emissions.

[0011] The object is achieved by a burner part according to the teaching of claim 1 and a burner according to claim 13.

[0012] Advantageous embodiments are the subject of the dependent claims.

[0013] The subclaims can be combined as desired to achieve further advantages.

[0014] The following figures show examples of burner parts according to the invention and their use in a burner.

[0015] It shows

[0016] Figures 1, 10 each show a sketch of part of an exemplary burner with burner parts according to the invention, Figures 2 to 5 show burner parts according to the prior art, Figure 4 shows a section of Figure 1 for a 4-stage burner, Figure 5 shows a section of Figure 1 for a 2-stage

[0017] Burner,

[0018] Figures 6, 11 burner parts according to the invention and

[0019] Figure 7 is a sectional view of Fig. 6,

[0020] Figure 8, 9 Arrangements of a diaphragm,

[0021] Figures 12, 13 show in a perspective view an exemplary embodiment of the burner part according to the invention,

[0022] Figure 14 sketches in detail a vortex generator with a fuel nozzle.

[0023] The figures and the description represent only embodiments of the invention.

[0024] Figure 1 schematically shows a part of a burner 1 with a burner part 11 according to the invention.

[0025] However, the invention largely arises from the interior of the burner part 11. Therefore, this also corresponds to an arrangement according to the prior art

[0026] Figure 10 shows a part of a burner 1' of another

[0027] Embodiment of the burner part 11' with vortex generators 17 sketched.

[0028] The embodiments of the burners 1, 1' according to the invention each comprise a main burner 3 which surrounds a pilot burner 6 in a ring shape.

[0029] The main burner 3 has an annular flow channel 2 which is delimited by an inner channel wall 4 of the pilot burner 6 and an outer channel wall 5.

[0030] Within the flow channel 2, several burner parts 11 (Fig. 2), 11' (Fig. 10) according to the invention are arranged distributed in the circumferential direction.

[0031] Figures 2, 3, 4, 5 show burner parts 9, 9' from the prior art in more detail.

[0032] The burner parts 9, 9' as well as the burner parts 11, 11' according to the invention essentially have the shape of a blade of a turbine blade.

[0033] The burner parts 9, 9', 11, 11' have a front edge 12, a rear edge 13 and a component wall 14.

[0034] Fuel nozzles 19 from which the fuel flows are arranged on the respective component walls 14.

[0035] The four-stage burner part 9 in Figure 2 has an A-access 30 for fuel for stage A of combustion and a B-access 33 for stage B of combustion.

[0036] The two-stage burner part 9' in Figure 3 has only the A access 41.

[0037] Figure 4 shows the burner part 9 in cross-section in the installed state.

[0038] The two upstream cavities (feed channel for fuel) 32, 35 for an A access 30 (32) and a B access 33 (35) respectively, which carry the fuel for stage A and stage B, can be seen.

[0039] Each level has its own access.

[0040] The corresponding holes or nozzles from which the fuel exits into channel 2 are not shown in detail here, but can be seen in the other figures (this applies to all drawings).

[0041] There is also an access 36 for an oil burner.

[0042] In Figure 5, the burner part 9' for a two-stage burner according to Figure 3 is shown in cross-section, but which has only one upstream cavity 42 and only one access 41.

[0043] A burner part according to the invention is shown in Figures 6 (burner part 11), 7 (in cross-section for burner parts 11, 11'). In addition to a stage A 40, the burner part 11, 11' also has a stage B 43, which, however, are supplied via a single, common, upstream cavity 83 and a single access 81 (Figure 7).

[0044] In the burner part 11, 11' according to the invention, the fuel stages (A + B) have the same feed channel or cavity 83 (Fig. 7) according to a four-stage variant.

[0045] Stage B 43 according to Figure 7 has the same mass flow and penetration depth as in the 4-stage design ( Figure 4 ).

[0046] There are several ways to achieve this. One possibility is to use an additional aperture of 50 in the range of stop B43, which enables these properties.

[0047] Figure 9 shows the aperture 50 in an enlarged view. Preferably, the aperture 50 is inserted into an annular recess 53 (Fig. 8) at the beginning of the step B 43

[0048] ( Fig . 9 ) .

[0049] The orifice 50 controls the fuel in terms of mass flow and penetration depth without valves and without a separate cavity.

[0050] Different mass flows of the B-stage can be set using different orifices.

[0051] Burner parts 9 ' in a two-stage variant according to Figure 5 can also be converted into the variant according to the invention.

[0052] The burner part of the present type is provided as a component of a burner. The type of burner 1, 1' is initially unimportant, however the burner part is advantageously used in a burner of a gas turbine. It is obvious that the burner should be arranged on the upstream side of a combustion chamber. In this case, the burner has a flow channel in which combustion air flows in a flow direction from the upstream side to the downstream side. The flow direction of the combustion air defines a flow direction. The burner part is deliberately arranged within the flow channel of the burner, so that the flow direction, the inflow side and the outflow side, also apply here. Next, a transverse direction is defined as a direction transverse to the flow direction.

[0053] When the burner part is arranged in the flow channel, it has a leading edge on the upstream side and a trailing edge on the downstream side. The leading edge and the trailing edge are each at the end of the burner part. The burner part further comprises a component wall which extends in the flow direction from the leading edge to the trailing edge. The component wall extends further in the transverse direction from a first wall end to an opposite second wall end. When arranged in the flow channel, the combustion air flows along the component wall.

[0054] To improve the mixing of the fuel in the combustion air, several vortex generators are arranged on the component wall protruding into the flow channel. The vortex generators (within the meaning of the invention, regardless of whether others are present elsewhere) are arranged near the leading edge and spaced apart from one another in the transverse direction. A position near the leading edge is assumed if the respective vortex generator is arranged at the same transverse position within an edge section of 20% of the distance from the leading edge to the trailing edge.

[0055] The vortex generators are then divided into a group of main vortex generators and an additional vortex generator. A first main vortex generator is arranged as one of the main vortex generators on the side facing the first wall end. A second main vortex generator is arranged next to the first vortex generator.

[0056] The burner component further comprises a number of fuel nozzles. The fuel nozzles (within the meaning of the invention, regardless of whether additional ones are present elsewhere) are each arranged downstream of a main vortex generator. This means that there is always an arrangement of a main vortex generator next to the leading edge together with a fuel nozzle downstream of the respective main vortex generator.

[0057] Even if the arrangement of a fuel nozzle downstream of a vortex generator is advantageous in itself, it has been shown that a further improvement in mixing can be achieved with an additional vortex generator without a fuel nozzle. The additional vortex generator is located between the first wall end and the first main vortex generator. If the additional vortex generator is dimensioned too large, the improvement provided by the additional vortex generator becomes a disadvantage for the mixing of the fuel with the combustion air. Therefore, the height of the additional vortex generator above the component wall must be less than the height of the adjacent first main vortex generator.

[0058] The vortex generators can be shaped differently, although it is advantageous to choose a triangular shape, with a leading curve at the combustion wall on the upstream side and a trailing curve perpendicular to the combustion wall on the downstream side. The height of the vortex generators increases from the upstream side to the downstream side.

[0059] This advantageously results in the top side of the vortex generators extending from the front curve to the free end of the rear curve. The height of the vortex generator is thus defined by the distance from the component wall to the free end of the trailing curve. In keeping with the triangular design, the vortex generator advantageously has two further opposite side surfaces, each extending from the trailing curve to one of the two ends of the guide curve. With regard to the position of the vortex generators (main vortex generator and additional vortex generator) near the leading edge, it is also advantageous to arrange them in the same position relative to the direction of flow. It is particularly advantageous if the trailing edge of the vortex generators is the same distance from the leading edge (which is assumed if the distances are within a range of + / - 10%).

[0060] With regard to the arrangement of the vortex generators, it is also advantageous to arrange them near or at the leading edge. Given the different sizes of the vortex generators and their preferred arrangement with the trailing curve at the same position in the flow direction, it is obvious that the largest main vortex generator is advantageously arranged such that the distance from the leading edge to at least one leading curve is less than 10% of the distance from the leading edge to the respective trailing curve of the largest main vortex generator.

[0061] Depending on the size of the burner part, in particular the width in the transverse direction from the first wall end to the second wall end, it is advantageous to arrange at least three and at most six main vortex generators, each with a fuel nozzle downstream of the respective main vortex generator. It is particularly advantageous to use four or five main vortex generators. Thus, a third vortex generator is arranged next to the second vortex generator on the side facing the second wall end, and a fourth vortex generator is arranged next to the third vortex generator on the side facing the second wall end. If necessary, a fifth vortex generator is arranged next to the fourth vortex generator on the side facing the second wall end.

[0062] When using a third and especially a fourth main vortex generator, it is advantageous to further increase the size starting from the first main vortex generator via the second main vortex generator, so that the third

[0063] Main vortex generator is larger than the second

[0064] main vortex generator and the fourth main vortex generator is larger than the third main vortex generator .

[0065] Regarding the further specific position of the additional vortex generator without a fuel nozzle, it is advantageous to arrange it midway between the first wall end and the first main vortex generator. This is assumed to be the case if the position lies within a tolerance of 15% of the distance from the first wall end to the first main vortex generator.

[0066] It should be noted that for the position of a vortex generator in the transverse direction, the mean or trailing curve of the vortex generator is considered.

[0067] With this arrangement of the additional vortex generator at half the distance from the first wall end to the first main vortex generator, it is further advantageous to arrange the first main vortex generator at half the distance from the first wall end to the second main vortex generator. Here, too, it is assumed that the preferred position is when the first main vortex generator is arranged midway between the first wall end and the second main vortex generator, with a tolerance of 15% of the distance from the first wall end to the second main vortex generator.

[0068] Since the effect of this arrangement of the additional vortex generator decreases with each additional main vortex generator, it is preferred to arrange the preferred third main vortex generator at a distance from the second main vortex generator that is at least 1.2 times and at most 1.5 times the distance between the second main vortex generator and the first main vortex generator. With the fuel nozzles, it is advantageous to arrange them close to the respective main vortex generators. Therefore, the distance between the vortex generator and the respective fuel nozzle should be less than half the length of the vortex generator. In particular, it is preferred that the distance from the respective main vortex generator to the center of the fuel nozzle is less than half the distance between the front curve and the rear curve of the respective main vortex generator.

[0069] The burner section, deliberately arranged in a flow channel, could also be designed differently (except for the component wall with the vortex generators and the fuel nozzles). However, it is advantageous to design the burner section in the shape of a vane. This allows for low-resistance guidance of the combustion air flow.

[0070] A preferred embodiment of the burner according to the invention has a central burner axis and an annular flow channel which extends from an upstream side to a downstream side. The flow channel is bounded on the radially inner side by an inner flow channel wall and on the radially outer side by an outer flow channel wall. A plurality of burner components according to the preceding description are arranged within the flow channel. The first wall end of the burner parts is fastened to the inner flow channel wall and the second wall end of the burner part is fastened to the outer flow channel wall.

[0071] Of course, it is possible to realize the burner part as a separate part, e.g., mounted between the inner and outer duct walls. On the other hand, it is possible to build the burner integrally with the inner and outer duct walls and the burner parts, e.g., through additive manufacturing. Further manufacturing options are of course possible for combining the burner part with the inner and outer duct walls.

[0072] As can be seen in Figure 11, the burner part 11' has the shape of a wing with a component wall 14 which extends from a leading edge 12 of the burner part to a trailing edge 13 of the burner part. The component wall is further delimited by a first side end 15 and an opposite second side end 16. The direction from the leading edge on an upstream side to the trailing edge 13 on the downstream side defines a flow direction. A transverse direction from the first side end 15 to the second side end 16 is defined transversely to the flow direction.

[0073] As can be seen in Figures 11, a series of vortex generators 17 are arranged near the leading edge 12.

[0074] Regarding Figures 12 and 13: There are four main vortex generators 17a, 17b, 17c, and 17d. Their size and height increase from a first main vortex generator 17a on the side facing the first wall end 15, through the second main vortex generator 17b, to the third main vortex generator 17c. The fourth main vortex generator 17d is smaller than the change from the first main vortex generator 17a to the third main vortex generator 17c. In this embodiment, the vortex generators 17, 18 are arranged with their downstream ends at the same position in the flow direction. This has the consequence that the third main vortex generator 17c, as the largest, is arranged with its upstream end very close to the leading edge 12, whereby the distance from the leading edge 12 to the first main vortex generator 17a (and also to the fourth main vortex generator 17d with reduced size) increases.

[0075] The main vortex generators 17 are characterized in that a fuel nozzle 19a-19d is arranged downstream of each main vortex generator 17a-17d. As can be seen, the distance from the fuel nozzles 19 to the respective main vortex generator 17 is significantly smaller than the size of the vortex generators 17.

[0076] The improved mixing is achieved by the additional vortex generator 18, which is arranged between the first main vortex generator 17a and the first wall end 15. In contrast to the main vortex generators 17, no fuel nozzle is arranged on the additional vortex generator 18. Furthermore, the size of the additional vortex generator 18 is reduced compared to the first main vortex generator 17a.

[0077] Figure 14 shows a detailed view of a main vortex generator 17 arranged on the component wall 14. As can be seen, the main vortex generator 17 has a triangular shape with a leading curve 22 as a transition from an upper side 24 of the main vortex generator 17 to the component wall 14 and a trailing curve 23 which runs transversely to the component wall and thus defines the height of the main vortex generator 17. This leads to two opposite side walls 25 which extend from the trailing curve 23 to one of the two opposite ends of the guide curve 22. A fuel nozzle 19 is arranged downstream of the main vortex generator 17.

Claims

Patent claims 1. Burner part (11, 11') for use in a burner (1, 1'), in particular for a gas turbine, which is arranged within a flow channel (2) with a flow direction, with an upstream leading edge (12) and a downstream trailing edge (13), with a component wall (14) which extends from the leading edge (12) to the trailing edge (13) and in a transverse direction transverse to the flow direction from a first wall end (15) to an opposite second wall end (16), comprising two stages (40, 43) of combustion, the two stages A, B (40, 43) being supplied via a common cavity (83).

2. Burner part according to claim 1, wherein the stage B (43) is provided at the beginning with an aperture (50).

3. Burner part according to claim 2, wherein the aperture (50) is arranged in a recess (53) at the beginning of the second stage (43).

4. Burner part (11') according to one or more of claims 1, 2 or 3, in which vortex generators (17, 18) which are arranged on the component wall (14) near the front edge (12) spaced apart from one another in the transverse direction and project into the flow channel (02), with a first main vortex generator (17a) on the side facing the first wall end (15) and a second main vortex generator (17b) next to the first Main vortex generator (17a) and an additional vortex generator (18); and - fuel nozzles (19) which are each arranged downstream of a main vortex generator (17), characterized in that the additional vortex generator (18) is arranged between the first main vortex generator (17a) and the first wall end (15) and has a height above the component wall (14) which is less than the height of the first main vortex generator (17a) and without a respective fuel nozzle.

5. Burner part according to claim 4, wherein the vortex generators (17, 18) are triangular in shape, with an upstream leading curve (22) on the component wall (14) and a downstream trailing curve (23) transverse to the component wall (14) or wherein the vortex generators (17, 18) have a cover surface (24) extending from the front curve (22) to the free end of the rear curve (23) and two side surfaces (25) each extending from one end of the front curve (22) to the rear curve (23).

6. Burner part according to one of claims 4 or 5, wherein the vortex generators (17, 18) are arranged in the same position to the flow direction.

7. Burner part according to claim 6, wherein the vortex generators (17, 18) are arranged near the front edge (12).

8. Burner part according to one of claims 4 to 7, with at least three and at most six, in particular four or five, main vortex generators (17) each with a downstream fuel nozzle (19).

9. Burner part according to claim 8, wherein the second main vortex generator (17b) is larger than the first vortex generator (17a) and a third main vortex generator (17c) next to the second vortex generator (17b) is larger than the second vortex generator (17b).

10. Burner part according to one of claims 3 to 9, wherein the additional vortex generator (18) is arranged centrally with a tolerance of 15% between the first wall end (15) and the first main vortex generator (17a) and wherein the first main vortex generator (17a) is arranged centrally with a tolerance of 15% between the first wall end (15) and the second main vortex generator (17b).

11. Burner part according to claim 10, wherein the distance between the third main vortex generator (17c) and the second main vortex generator (17b) is at least 1.2 times and at most 1.5 times the distance between the second main vortex generator (17b) and the first main vortex generator (17a), or wherein the distance from the trailing curve (23) to the respective fuel nozzle (19) is less than half the length of the respective main vortex generator (17) in the flow direction, in particular less than half the respective distance from the pre-curve (22) to the trailing curve (23).

12. Burner part according to one of claims 1 to 11, having the shape of a blade.

13. Burner (1, 1') with at least one, in particular several burner parts (11, 11') according to one of the preceding claims.

14. Burner part (11, 11') according to one or more of the preceding claims, wherein the cavity (83) is formed in the burner part (11, 11').

15. Burner part (11, 11') according to claim 14, wherein the cavity (83) can be supplied with fuel only through a single access (81).

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