DE102023203273A1 - Improved burner part and burner with such a burner part - Google Patents

Abstract

The invention relates to a burner part (11) for use in a burner (1), 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, wherein the two stages (40, 43) are supplied via a common cavity (83).

Description

The invention relates to a burner part for use in a burner.

In the newer versions of gas turbines, a higher turbine inlet temperature and higher temperatures in the combustion zone (TiTiso; TPZ) and an increasing mass flow are achieved with low NOx emissions at the same time. For this purpose, a modified and improved burner part for the main burner was developed and successfully tested and used.

In order to remain competitive with machines already in use, these requirements must also be met.

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

For favorable 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 the fuel is burned. To achieve this, various solutions are used in the state of the art. In many cases, these are based on the generation of turbulence between the combustion air and the fuel. Although turbulence leads to resistance in the flow, it is usually 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 that deflect the flow and create turbulence. In many cases, blade-like structures are used for this purpose. It is also known to arrange disruptive contours on the surface along the flow path that cause turbulence in the combustion air. For example, it is known to arrange so-called vortex generators on the wall of a flow channel that protrude into the flow channel.

It is therefore the object of the present invention to achieve reduced NOx emissions in existing plants. The object of the invention is therefore to improve the burner part in order to achieve a reduction in NOx emissions.

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

Advantageous embodiments are the subject of the subclaims.

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

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

• 1, 10 jeweils skizzenhaft einen Teil eines beispielhaften Brenners mit erfindungsgemäße Brennerteilen,
• 2 bis 5 Brennerteile nach dem Stand der Technik,
• 4 einen Schnitt von 1 für einen 4-stufigen Brenner,
• 5 einen Schnitt von 1 für einen 2-stufigen Brenner,
• 6, 11 erfindungsgemäße Brennerteile und
• 7 eine Schnittdarstellung von 6,
• 8, 9 Anordnungen einer Blende,
• 12, 13 zeigen in einer perspektivischen Ansicht eine beispielhafte Ausführungsform des erfindungsgemäßen Brennerteils,
• 14 skizziert im Detail einen Wirbelgenerator mit einer Brennstoffdüse.

It shows

• 1 , 10 each sketch a part of an exemplary burner with burner parts according to the invention,
• 2 to 5 Burner parts according to the state of the art,
• 4 a cut of 1 for a 4-stage burner,
• 5 a cut of 1 for a 2-stage burner,
• 6 , 11 burner parts according to the invention and
• 7 a cross-sectional view of 6 ,
• 8 , 9 Arrangements of a diaphragm,
• 12 , 13 show in a perspective view an exemplary embodiment of the burner part according to the invention,
• 14 outlines in detail a vortex generator with a fuel nozzle.

The figures and the description represent only embodiments of the invention.

In 1 a part of a burner 1 with a burner part 11 according to the invention is schematically sketched. However, the invention is largely only apparent from the interior of the burner part 11. Therefore, this also corresponds to an arrangement according to the prior art

In 10 a part of a burner 1' of a further embodiment of the burner part 11' with vortex generators 17 is outlined.

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

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

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

In the 2 , 3 , 4 , 5 Burner parts 9, 9' from the prior art are shown in more detail.

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

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

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

The four-stage burner part 9 in 2 has an A-inlet 30 for fuel for stage A of combustion and a B-inlet 33 for stage B of combustion.

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

In 4 the burner part 9 can be seen in cross-section in the installed state.

The two upstream cavities (fuel feed channel) 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.

Each level has its own access.

The corresponding holes or nozzles through 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).

There is also an access 36 for an oil burner.

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

A burner part according to the invention is 6 (burner part 11), 7 (in cross-section for burner parts 11, 11'). The burner part 11, 11' has a stage A 40 and a stage B 43, which are supplied via a single, common, upstream cavity 83 and a single access 81 ( 7 ).

In the burner part 11, 11' according to the invention, the fuel stages (A + B) have the same feed channel or cavity 83 ( 7 ).

Level B 43 according to 7 has the same mass flow and penetration depth as the 4-stage design ( 4 ) on.

There are various ways to achieve this. One option is to use an additional aperture of 50 in the area of stop B 43, which enables these properties.

9 shows the aperture 50 in an enlarged view. Preferably, the aperture 50 is inserted into an annular recess 53 ( 8 ) at the beginning of level B 43 ( 9 ).

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

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

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

The burner part of the present type is intended as a component of a burner. The type of burner 1, 1' is initially unimportant, but 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.

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 meant 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 the second wall end. When arranged in the flow channel, the combustion air flows along the component wall.

To improve the mixing of the fuel in the combustion air, several vortex generators are arranged on the component wall that protrudes into the flow channel. The vortex generators (in the sense of the invention, regardless of whether others are present elsewhere) are arranged close to the front edge and spaced apart from one another in the transverse direction. A position close to the front 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 front edge to the rear edge.

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.

The burner component further comprises a number of fuel nozzles. The fuel nozzles (in the sense of the invention, regardless of whether others are present elsewhere) are each arranged downstream of a main vortex generator. This means that there is always the arrangement of a main vortex generator next to the leading edge together with a fuel nozzle downstream of the respective main vortex generator.

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 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 lower than the height of the adjacent first main vortex generator.

The vortex generators can have different shapes, but it is advantageous to choose a triangular shape with a leading curve on the combustion wall on the upstream side and a trailing curve across the combustion wall on the downstream side. The height of the vortex generators increases from the inflow side to the outflow side.

This advantageously means that the top of the vortex generators extends 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 drag curve. In accordance with the triangular design, the vortex generator advantageously has two additional opposite side surfaces, each of which extends from the drag 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 to the flow direction. 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%).

With regard to the arrangement of the vortex generators, it is also advantageous to arrange them close to 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.

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. For example, 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.

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 main vortex generator generator is larger than the second main vortex generator and the fourth main vortex generator is larger than the third main vortex generator.

With regard to the further specific position of the additional vortex generator without fuel nozzle, it is advantageous to arrange it in the middle between the first wall end and the first main vortex generator. This is assumed to be given if the position is within a tolerance of 15% of the distance from the first wall end to the first main vortex generator.

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

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 also 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 in the middle 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.

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.

For 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.

The burner part, which is 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 part in the form of a blade. This enables the combustion air flow to be guided with little resistance.

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 delimited on the radial inside by an inner flow channel wall and on the radial outside by an outer flow channel wall. Several burner components are arranged within the flow channel in accordance with the previous description. The first wall end of the burner parts is attached to the inner flow channel wall and the second wall end of the burner part is attached to the outer flow channel wall.

Of course, it is possible to realize the burner part as a separate part, e.g. mounted between the inner channel wall and the outer channel wall. On the other hand, it is possible to build the burner with the inner channel wall and the outer channel wall and the burner parts integrally, e.g. by additive manufacturing. Other manufacturing options are of course possible to combine the burner part with the inner channel wall and the outer channel wall.

As in 11 As can be seen, the burner part 11' has the shape of a wing with a component wall 14 which extends from a front edge 12 of the burner part to a rear 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 front edge on an upstream side to the rear 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.

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

To the 12 , 13 : Here there are four main vortex generators 17a, 17b, 17c and 17d. Their size and height increases from a first main vortex generator 17a on the side facing the first wall end 15 via the second main vortex generator 17b to the third main vortex generator 17c. The fourth main vortex generator 17d has a reduced size compared to 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 end at the same position in the flow direction. This means that the third Main vortex generator 17c, as the largest, is arranged with its upstream end very close to the leading edge 12, thereby increasing the distance to the leading edge 12 to the first main vortex generator 17a (and also to the fourth main vortex generator 17d with reduced size).

The main vortex generators 17 are characterized in that a fuel nozzle 19a-19d is arranged downstream of them on 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.

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.

In 14 a detailed view of a main vortex generator 17 arranged on the component wall 14 is sketched. 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 that 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 that 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 (13)

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, wherein the two stages A, B (40, 43) are supplied via a common cavity (83). burner part after claim 1 , in which the stage B (43) is provided at the beginning with an aperture (50). burner part after claim 2 , in which the aperture (50) is arranged in a recess (53) at the beginning of the second stage (43). Burner part (11') according to one or more of the Claims 1 , 2 or 3 , in which vortex generators (17, 18) which are arranged on the component wall (14) near the front edge (12) at a distance from one another in the transverse direction and protrude 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 is without a respective fuel nozzle. burner part after 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). Burner part according to one of the Claims 4 or 5 , wherein the vortex generators (17, 18) are arranged in the same position to the flow direction. burner part after claim 6 , wherein the vortex generators (17, 18) are arranged near the leading edge (12). Burner part according to one of the Claims 4 until 7 , with at least three and a maximum of six, in particular four or five, main vortex generators (17), each with a downstream fuel nozzle (19). burner part after claim 8 , wherein the second main vortex generator (17b) is larger than the first vortex generator (17a) and a third main vortex generator (17c) adjacent to the second vortex generator (17b) is larger than the second vortex generator (17b). Burner part according to one of the Claims 3 until 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). burner part after 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 drag 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 drag curve (23). Burner part according to one of the Claims 1 until 11 , with the shape of a shovel. Burner (1, 1') with at least one, in particular several burner parts (11, 11') according to one of the preceding claims.

Images