EP2513562B1 - Burner for a turbine - Google Patents

Description

The invention relates to a burner for a turbine, and more particularly to a burner for a turbine provided with a means for premixing oxidant and fuel.

In order to achieve low emission levels, turbines such as e.g. Gas turbines called "premix burner" or "Premix Burner" used. By using premix technology, the mixing process of fuel and oxidant, such as air, is decoupled from the actual combustion process, i. preceded by this. This allows the peak combustion temperatures to be lowered. At the same time, the residence time of the fuel-oxidant mixture (e.g., fuel-air mixture) in the reaction zone may be shortened. In particular, this reduces the formation of NOx (especially thermal NOx). There are various "premix burners" in the atmospheric combustion and combustion under pressure in use. Also in the field of gas turbines different burners are used. With an optimal burner, combustion in a large operating range should be stable, controlled, low in emissions and as complete as possible. Here again and again the quality of the mixture of fuel and oxidant is the focus of interest. The mixture is crucial for the local combustion temperature and thus for the reaction products, i. the emissions. Therefore, the location and aerodynamics of the fuel injection must be carefully chosen.

DE 10 2008 019 117 A1 describes a burner provided with means for premixing air and fuel for a turbine. According to this document, the burner has a cylindrical combustion chamber for gaseous or liquid fuel and a Haupindindüsung. The combustion chamber is in an axial direction of the burner bounded on one side by a burner bottom and radially by a flame tube. The main injection is used to inject a premixed fuel-air mixture. Injection takes place radially to a burner longitudinal axis via main nozzles which open into a radial swirl generator. The radial swirl generator is arranged between the burner base and the flame tube and causes the fuel-air mixture to be subjected to a swirl pulse and swirled into the combustion chamber.

Other burners provided with a means for premixing oxidant and fuel are disclosed in US Pat DE 198 59 210 A1 and in DE 38 19 898 A1 described.

US 5,394,688 and EP 0 982 545 A2 show burner for turbines according to the preamble of claim 1. The invention has for its object to provide a burner for a turbine, in a simple and cost-effective manner an extremely homogeneous premix to be introduced into a combustion chamber of the burner fuel-oxidizer mixture, such as For example, a fuel-air mixture is achieved.

This is achieved with a burner according to claim 1. Further developments of the invention are defined in the dependent claims.

According to the invention, a burner for a turbine comprises: a flame tube, in which a combustion chamber is formed, a jacket, which surrounds the flame tube from radially outside with a predetermined distance thereof, so that an oxidant collecting space is formed between flame tube and jacket, a burner bottom defining the oxidizer plenum and the combustion chamber at an axial end of the burner, and a swirler axially the burner bottom and is arranged radially adjacent to the oxidant collecting chamber axially between the flame tube and the burner bottom, for supplying a fuel-oxidant mixture into the combustion chamber, wherein the swirl generator along with a circumferential direction of the burner Having circumferentially spaced plurality of vanes, so that the respective distances between the vanes form a plurality of in their course each having a tangential component having radial inlet passages to the combustion chamber, wherein in each Inlasströmungsbereich at least some of the plurality of inlet passages is provided in each case one Brennstoffzuführrohr which extends with respect to its length in an axial direction of the burner and transversely to an oxidant flow direction through the respective inlet passage, and wherein each fuel feed tube has in its wall at least one with respect to the Brennstoffzuführrohrs radial fuel discharge opening, via the fuel with a transverse to the Oxidationsmittel- Flow direction extending direction component is einmischbar in the respective inlet passage and at least one of the fuel supply pipes with respect to the Längsmittelach se of the respective intake passage is arranged off-center in the respective intake passage. According to the invention, this arrangement of one or more or all Brennstoffzuführrohre is advantageous because the respective eccentric position in the inlet passage transverse to the longitudinal central axis freely selectable and thus the turbulence of the fuel is freely changeable.

Preferably, air is provided as the oxidizing agent, which is fed at atmospheric or elevated pressure into the oxidant collecting space.

Due to the fact that in the burner according to the invention the fuel injection takes place inside the inlet passages or air passages of the swirl generator through individual fuel supply pipes with a directional component running transversely to the oxidant flow direction, an extremely homogeneous premix of the catalyst into the combustion chamber of the swirl generator is produced in a simple and cost-effective manner Brenners introduced fuel-oxidizer mixture, such as a fuel-air mixture achieved.

The freedom of design of the fuel dispensing opening (s), which is preferably formed as a bore, and the arbitrary positioning of the Brennstoffzuführrohre and the Brennstoffausgabeöffnung (s) within the respective Einlassströmungsbereiche or on the respective fuel supply pipes, can be an optimal premix of fuel (Eg fuel gas) and oxidizing agents (eg air) can be achieved. As the fuel composition changes, the fuel delivery ports may be sized and shaped.

According to one embodiment of the invention, all inlet passages are each provided with a fuel feed pipe.

This advantageously promotes particularly homogeneous mixing of fuel and oxidant prior to introduction into the combustion chamber.

According to yet another embodiment of the invention, at least one of the fuel supply tubes is in the oxidant flow direction directly in front of the respective inlet passage, that is arranged at the beginning of Einlasströmungsbereichs.

This embodiment of the invention represents a further advantageous variant for the arrangement of one or more or all Brennstoffzuführrohre, wherein the mixing length or mixing distance of fuel and oxidant is maximally extended.

According to an embodiment of the invention, at least one of the fuel supply pipes or a plurality or all of the fuel supply pipes is arranged centrally in the respective intake passage with respect to the longitudinal central axis of the respective intake passage.

According to another embodiment of the invention, at least one of the fuel supply pipes has a plurality of fuel discharge openings spaced along the length of the fuel supply pipe.

With this embodiment of the invention, the homogeneous mixing of fuel and oxidant can be further improved. Preferably, therefore, several or all of the fuel supply pipes are each provided with a plurality of fuel discharge openings spaced apart from each other along the length of the fuel supply pipes.

According to yet another embodiment of the invention, at least one of the fuel supply pipes has two fuel discharge openings which are arranged at the same position with respect to the length of the fuel supply pipe, so that fuel can be dispensed from the fuel supply pipe via these two fuel discharge openings with two opposing directional components.

According to this embodiment of the invention, by oppositely outputting the fuel into the intake passage, the oxidant flow on both sides of the fuel supply pipe is utilized for fluidizing the fuel, thereby further improving homogeneous mixing of fuel and oxidant.

Preferably, several or all of the fuel supply pipes each have two fuel discharge openings, which are arranged at the same position with respect to the length of the fuel supply pipe, so that fuel can be dispensed from the fuel supply pipe via these two fuel discharge openings with two opposing directional components.

More preferably, each fuel discharge opening of a respective fuel supply pipe has such a fuel discharge port arranged at the same position with respect to the length of the fuel supply pipe to dispose its fuel with an opposite direction component.

In addition to optimal "standard positions" can of course also individual optimizations in terms of emissions and Rückzündverhalten- depending on fuel consequences.

According to further embodiments of the invention, as seen in cross section of the respective fuel supply pipe, the two fuel discharge openings are diametrically opposed to each other or include respective longitudinal center axes of the two fuel discharge openings at an obtuse angle.

Also with this embodiment of the invention can in a simple and efficient way, the strength of the turbulence and the entrainment of the fuel in the Oxidized and thus optimized for the particular application.

According to further embodiments of the invention, the Brennstoffzuführrohre each have a cylindrical cross-section or a wing-shaped cross section or other suitable for optimum turbulence cross sections. According to the invention, all fuel supply pipes can have the same cross-sectional shape. Embodiments in which groups of fuel supply pipes are formed, wherein within a group all the fuel supply pipes have the same cross-sectional shape, but the groups have different cross-sectional shapes, are also possible.

For example, the airfoil shape may prove advantageous for reducing direct mixing in the pipe wake, which may be particularly necessary with reactive fuels (such as hydrogen).

According to another embodiment of the invention, the fuel supply pipes are each detachably mounted so that each fuel supply pipe formed according to a predetermined fuel-in configuration is individually replaceable with a fuel supply pipe according to another predetermined fuel-in configuration when needed.

Due to the simple interchangeability of the fuel supply pipes, a simple and rapid adaptation of the burner during a fuel change can be carried out. Typically, the burner according to the invention is suitable for the use of fuel gas as fuel. However, the burner according to the invention can also be operated with liquid fuel, wherein, if necessary, special nozzles should be inserted into the fuel discharge openings.

The use of the central fuel supply tubes in the inlet passages of the swirler enables optimum mixtures of fuel (e.g., fuel gas) and oxidant (e.g., air). This low emissions can be achieved. At the same time, by customizing the fuel delivery apertures and / or positioning the fuel supply tubes, one may rely on locally different oxidant distributions, such as e.g. locally different air distributions, be reacted. Due to the central replaceable fuel supply pipes solution of the invention is very inexpensive.

Fig.1

zeigt in einer schematischen Längsschnittansicht den Aufbau eines Brenners einer Gasturbine gemäß einer Ausführungsform der Erfindung.

Fig.2

zeigt eine schematische Querschnittsansicht eines Teils des Brenners von Fig. 1, gesehen entlang einer Linie A-A in Fig.1.

Fig.3

zeigt in vergrößerten Teilansichten einer Einlasspassage des Brenners von Fig.2 drei mögliche Konfigurationsvarianten eines Brennstoffzuführrohrs.

Fig.4

zeigt zwei mögliche Konfigurationsvarianten eines Brennstoffzuführrohrs in einer Einlasspassage des erfindungsgemäßen Brenners, gesehen entlang einer Linie B-B in Fig.2.

In the following the invention will be described in more detail by means of preferred embodiments and with reference to the attached figures.

Fig.1

shows in a schematic longitudinal sectional view of the structure of a burner of a gas turbine according to an embodiment of the invention.

Fig.2

shows a schematic cross-sectional view of a portion of the burner of Fig. 1 , seen along a line AA in Fig.1 ,

Figure 3

shows in enlarged partial views of an inlet passage of the burner of Fig.2 three possible configuration variants of a fuel supply pipe.

Figure 4

shows two possible configuration variants of a Brennstoffzuführrohrs in an intake passage of the burner according to the invention, as seen along a line BB in Fig.2 ,

Fig.1 shows the structure of a burner 1 of a gas turbine (not fully shown) according to an embodiment of the invention.

The burner 1 has a flame tube 10, in which a combustion chamber 11 is formed, and a tubular jacket 20, the flame tube 10 from radially outward encloses it with a predetermined distance, so that between the flame tube 10 and shell 20, an oxidant-collecting space 21 is formed.

As the fuel for the burner 1, fuel gas is provided, and as the oxidizing agent for the fuel gas, atmospheric air is provided, which is compressed by a compressor (not shown) and then supplied to the oxidant collecting space 21.

The burner 1 further includes a burner bottom 30 delimiting the oxidizer plenum 21 and the combustion chamber 11 at an axial end of the combustor 1, and a swirler 40 axially axially adjacent to the combustor bottom 30 and radially adjacent to the oxidizer plenum 21 Flame tube 10 and the burner bottom 30 is arranged for supplying a fuel-oxidant mixture BOG in the combustion chamber eleventh

With additional reference to Fig.2 which one along a line AA in Fig.1 seen sectional view of a part of the burner of Fig. 1 1, the swirl generator 40 has a plurality of (here eight) vanes 41, each circumferentially spaced apart along a circumferential direction UR of the burner 1.

The guide vanes 41 are each shaped and arranged in such a way that the respective distances between the guide vanes 41 form a plurality (in this case eight) of radial inlet passages 42 each having a tangential component in their course towards the combustion chamber 11.

In a respective intake flow area of at least some of the plurality of intake passages 42, there is provided a fuel supply pipe 43a, 43b, 43c, 43d each having a length in an axial direction AR (see FIG Fig.1 ) of the burner 1 and across an oxidant flow direction OR through the respective inlet passage 42.

Although in Fig.2 only four of the eight inlet passages 42 a Brennstoffzuführrohr 43a, 43b, 43c, 43d is shown, according to not shown embodiments of the invention may be provided in more or less or in all inlet passages 42 respective fuel supply pipes 43a, 43b, 43c, 43d.

As in the Figures 3 and 4 1, each fuel supply pipe 43a, 43b, 43c, 43d has in its wall at least one fuel discharge opening 44, 45 radial to the fuel supply pipe 43a, 43b, 43c, 43d via which fuel BS has a directional component transverse to the oxidant flow direction OS respective inlet passage 42 is einmischbar. Preferably, each fuel dispensing opening 44, 45 is formed as a bore or as a nozzle insert.

How out Fig.2 As can be seen, one or more or all fuel supply pipes 43a, 43b, 43d may be disposed directly in the respective intake passages 42. Like also out Fig.2 As can be seen, the fuel supply pipes 43a, 43b, 43d may be disposed within the respective intake passages 42 at different positions along the length of the respective intake passages 42.

On the other hand, one, several or all of the fuel supply pipes 43c in the oxidant flow direction OS can also be arranged directly in front of the respective inlet passages 42 (ie at the inlet of the respective inlet passages 42 partially or completely in the oxidant collecting chamber 21).

Like also out Fig.2 As can be seen, one or more or all fuel supply pipes 43a, 43b, 43c may be arranged centrally in the respective intake passages 42 with respect to longitudinal center axes L of the respective intake passages 42. According to the invention, one, several or all of the fuel supply pipes 43d are arranged eccentrically with respect to the longitudinal center axes L of the respective inlet passages 42.

How out Figure 4 As can be seen, one or more or all of the fuel supply pipes 43a, 43b, 43c, 43d may have a plurality of fuel discharge openings 44, 45 spaced along the respective length of the fuel supply pipes 43a, 43b, 43c, 43d [variant a ) in Figure 4 ]. On the other hand, one, several or all fuel supply pipes 43a, 43b, 43c, 43d may have only a single fuel discharge opening 44, 45 with respect to the respective length of the fuel supply pipes 43a, 43b, 43c, 43d [variant b] in FIG Figure 4 ].

How out Figure 3 can be one, several or all of the central fuel supply pipes 43a, 43b, 43c (in Figure 3 43a-c) and also one, several or all off-center fuel supply pipes 43d (in FIG Figure 3 not shown) have two fuel discharge openings 44, 45, which are arranged at the same position with respect to the length of the Brennstoffzuführrohrs, so that these two fuel discharge openings 44, 45 fuel BS with two opposite direction components (as indicated by the oppositely directed exit arrows for the fuel BS ) can be dispensed from the respective fuel supply pipe 43a, 43b, 43c, 43d.

How out Figure 3 It can also be seen that the two fuel dispensing openings 44, 45 can be located diametrically opposite one another in the cross section of the respective fuel feed pipe 43a, 43b, 43c, 43d [variant a) in FIG Figure 3 ] or can each longitudinal central axes L1, L2 of the two fuel discharge openings 44, 45 an obtuse angle α (45 ° <α <180 °) with each other include [variants b) and c) in Figure 3 ].

Of course, it would also be possible within the scope of the invention to alternate the fuel discharge openings 44, 45 diametrically opposite each other at the obtuse angle α with the length of the fuel supply pipe 43a, 43b, 43c, 43d so that at each longitudinal position of the fuel supply pipe 43a , 43b, 43c, 43d only a single fuel discharge openings 44, 45 is arranged.

Like from the Figures 2-4 As can be seen, the fuel supply pipes 43a, 43b, 43c, 43d each have a cylindrical cross section. However, according to non-illustrated embodiments of the invention, the fuel supply pipes 43a, 43b, 43c, 43d may also have a wing-shaped cross section or other cross-sectional shapes suitable for homogeneous mixing of oxidant and fuel. A hydrofoil shape is for example in DE 38 19 898 A1 in Fig.2 with reference to guide vanes.

Although in the FIGS. 1 to 4 not shown in detail, the fuel supply pipes 43a, 43b, 43c, 43d are each detachably mounted in the burner 1 so that each fuel supply pipe formed according to a predetermined fuel mixing configuration (position of the fuel supply pipe in the intake passage, number and arrangement of the fuel discharge ports, cross sectional shape of the fuel supply pipe) 43a, 43b, 43c, 43d, when needed, is individually replaceable with a fuel supply tube 43a, 43b, 43c, 43d according to another predetermined fuel mixing configuration.

For this purpose, the fuel supply pipes 43a, 43b, 43c, 43d (in FIG Figure 4 with 43a-d) as in Figure 4 shown releasably inserted into corresponding openings in the burner bottom 30, wherein each Brennstoffzuführrohr 43 a, 43 b, 43 c, 43 d at a longitudinal end thereof a flange or head portion 46, 47th which abuts on the side facing away from the swirl generator 40 side of the burner base 30 at this and is screwed by means of screws (not shown) with the burner bottom 30, for example.

Finally, it should be noted that each fuel feed tube 43a, 43b, 43c, 43d is naturally fluidly connected to a fuel source (not shown), such as a fuel gas tank, via respective conduits and control valves (both not shown).

LIST OF REFERENCE NUMBERS

1

burner

10

flame tube

11

combustion chamber

20

coat

21

Oxidant collecting space 21

30

Brenner ground

40

swirl generator

41

vane

42

intake passage

43a

fuel supply

43b

fuel supply

43c

fuel supply

43d

fuel supply

44

Fuel dispensing opening

45

Fuel dispensing opening

46

header

47

header

L

Longitudinal central axis

L1

Longitudinal central axis

L2

Longitudinal central axis

α

dull angle

UR

circumferentially

AR

axially

OR

Oxidant flow direction

BS

fuel

BOG

Fuel-oxidant mixture

Claims (8)

1. A burner (1) for a turbine, comprising:

   a flame tube (10), in which a combustion chamber (11) is formed,

   a jacket (20) which from radially outside encloses the flame tube (10) at a predetermined spacing thereof, so that between flame tube (10) and jacket (20) an oxidising agent collection space (21) is formed,

   a burner base (30), which delimits the oxidising agent collection space (21) and the combustion chamber (11) at an axial end of the burner (1), and

   a swirl generator (40), which, axially adjoining the burner base (30) and radially adjoining the oxidising agent collection space (21), is axially arranged between the flame tube (10) and burner base (30) for feeding a fuel oxidising agent mixture (BOG) into the combustion chamber (11),

   wherein the swirl generator comprises a plurality of guide vanes (41) each arranged along a circumferential direction (UR) of the burner (1) arranged circumferentially spaced from one another, so that the respective spacings between the guide vanes (41) form a plurality of radial inlet passages (42) towards the combustion chamber (11) each comprising a tangential component in their course,

   wherein in a respective inlet flow region at least of some of the plurality of inlet passages (42) a fuel feed tube (43a, 43b, 43c, 43d) is provided in each case, which with respect to its length extends in an axial direction (AR) of the burner (1) and transversely to an oxidising agent flow direction (OR) through the respective inlet passage (42), and

   wherein each fuel feed tube (43a, 43b, 43c, 43d) in its wall comprises at least one fuel output opening (44, 45) which is radial with respect to the fuel feed tube (43a, 43b, 43c, 43d), via which fuel (BS) can be admixed into the respective inlet passage (42) with a directional component running transversely to the oxidising agent flow direction (OR),

   characterized

   in that at least one of the fuel feed tubes (43d) is arranged out of centre in the respective inlet passage (42) with respect to the longitudinal centre axis (L) of the respective inlet passage (42).
2. The burner according to Claim 1, wherein at least one of the fuel feed tubes (43c) is arranged in the oxidising agent flow direction (OR) directly before the respective inlet passage (42).
3. The burner according to any one of the Claims 1 to 2, wherein at least one of the fuel feed tubes (43a, 43b, 43c) is arranged, with respect to a longitudinal centre axis (L) of the respective inlet passage (42), centrically in the respective inlet passage (42).
4. The burner according to any one of the Claims 1 to 3, wherein at least one of the fuel feed tubes (43a, 43b, 43c, 43d) comprises a plurality of fuel output openings (44, 45) which are arranged spaced from one another along the length of the fuel feed tube (43a, 43b, 43c, 43d).
5. The burne4 (1) according to any one of the Claims 1 to 4, wherein at least one of the fuel feed tubes (43a, 43b, 43c, 43d) comprises two fuel output openings (44, 45), which with respect to the length of the fuel feed tube (43a, 43b, 43c, 43d) are arranged in the same position that via these two fuel output openings (44, 45), fuel (BS) with two directional components opposing one another can be output from the fuel feed tube (43a, 43b, 43c, 43d).
6. The burner (1) according to Claim 5, wherein seen in the cross section of the respective fuel feed tube (43a, 43b, 43c, 43d), the two fuel output openings (44, 45) are located diametrically opposite one another or respective longitudinal centre axes (L1, L2) of the two fuel output openings (44, 45) include an obtuse angle (α) with one another.
7. The burner (1) according to any one of the Claims 1 to 6, wherein the fuel feed tubes (43a, 43b, 43c, 43d) each have a cylindrical cross section or a wing-shaped cross section.
8. The burner (1) according to any one of the Claims 1 to 7, wherein the fuel feed tubes (43a, 43b, 43c, 43d) are each detachably mounted so that each fuel feed tube (43a, 43b, 43c, 43d) formed according to a predetermined fuel admixing configuration can be individually exchanged if required against a fuel feed tube (43a, 43b, 43c, 43d) according to another predetermined fuel admixing configuration.

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