EP2310741B1 - Fuel nozzle insert - Google Patents

Description

The present invention relates to a fuel nozzle for the twisting of a fuel / air-fuel mixture. The invention further relates to a burner and a gas turbine.

Gas turbines are known to have the following components: a compressor for compressing air; a combustion chamber for generating hot gas by burning fuel in the presence of the compressed air supplied from the compressor; and a turbine in which the hot gas supplied from the combustion chamber is expanded. Gas turbines are known to emit undesirable nitrogen oxides (NOx) and carbon monoxide (CO). One known factor affecting NOx emissions is the combustion temperature. If the combustion temperature is lowered, the amount of NOx released decreases. However, high combustion temperatures are desirable to achieve high efficiency. It is known that leaner fuel / air mixtures burn cooler and therefore less NOx emissions arise. One known technique for producing a leaner fuel mixture is to create turbulence to mix air and fuel as evenly as possible prior to combustion to avoid creating zones of rich mixture in which there are high temperature localities (see called hot spots). In can, can annular, annular systems, therefore, fuel is flowed in via a so-called Swirler. Here, compressed air is supplied through a channel of the combustion chamber. In this channel Swirler are arranged, which are connected to a fuel line. These swirlers twist the combustion air and at the same time introduce fuel into the combustion air through holes in the swirl blades. This mixture then flows to the combustion chamber to be burned there. This system becomes a as homogeneous as possible mixture of fuel to air, which contributes significantly to the NOx reduction.

The GB 760 972 A discloses a nozzle in which the fluid to be injected is rotated in a circulation chamber located in the nozzle opening.

The DE 20 15 470 A1 discloses a spray nozzle in which the pressure level of the flow medium to be sprayed is converted into rotational kinetic energy in a circulation chamber.

The DE 22 32 686 A1 discloses a spray nozzle having a spiral vortex chamber disposed in the spray opening.

In combustion engines, in particular those which are operated with two different fuels, for example, an injection of the fuel oil via swirl generator, in which the oil is mixed with air. For better atomization and mixing of oil and air, the oil within the nozzles used for the injection can be set in a swirling motion. This swirl generation within the oil nozzle has hitherto been achieved in that these nozzles consist of a plurality of platelets which have bores at slightly different coordinates. By soldering together the individual platelets creates a spiral, which is used to spin the fuel. However, such nozzles have a structurally complex construction, since the holes must be placed accurately.

It is therefore a first object of the present invention to provide a fuel nozzle which overcomes the above-mentioned problems. A second object of the present invention is the disclosure of an advantageous burner. It is a third object of the invention to provide an advantageous gas turbine.

The first object is achieved by a fuel nozzle according to claim 1. The second task is done by a Bremer solved according to claim 12. The object related to the gas turbine is achieved by a gas turbine according to claim 15. The dependent claims contain further, advantageous embodiments of the invention.

According to the invention, it is therefore proposed here to arrange a component, namely the nozzle insert in another component, namely the receiving unit. Thereby, a flow path and a swirl chamber are formed. Thus, a simpler installation of the "nozzle" according to the invention is possible. Thus, fuel, in particular liquid fuel, flows through the flow path. The flow path can itself take on a kind of nozzle function in that it is formed differently geometrically, for example, when stream enters the swirl chamber tapers or widened. If the fuel is accelerated in the flow path, that is, the greatest speed is only on entry into the recording unit itself, so too high pressure losses and cavitations can be avoided. At the entrance of the fuel and at the end, that is essentially in the swirl chamber itself, the nozzle insert is bent in a substantially circular shape, and thus essentially forms a broken circle. Flow thus emerges here from a flow path and into a swirl chamber in such a way that the fuel performs a circular, in particular a spiral movement in the swirl chamber. The nozzle insert according to the invention thus produces a swirl component in the swirl chamber, in particular also in the combustion chamber downstream. In this case, a depth of the receiving unit decreases at the inlet beginning of the nozzle insert in the flow direction. This causes the flow rate of the fuel to be changed, namely increased.

It is also the flow path, which is formed by the inlet beginning of the nozzle insert and the receiving unit, taper in the flow direction. This also causes an increase in the flow velocity. Alternatively, the flow path, which is formed by the entry start of the nozzle insert and the receiving unit, also expand in the flow direction. This also causes a change in the flow velocity. With simultaneous reduction of the depth of the receiving unit at the inlet beginning in the flow direction can also be done so increasing the flow velocity.

Preferably, the nozzle insert can be used as an integrated component in the receiving unit. The swirl chamber is preferably designed circular. Thus, the fuel inlet with its semicircular curved inlet beginning and End are particularly stable integrated into the recording unit. But other geometric shapes are conceivable. The swirl chamber may further comprise an outlet, so that the fuel twisted can escape there. The outlet thus serves as a spray nozzle and may, for example, also have a tapered shape. The so twisted fuel then enters the combustion chamber. Preferably, the outlet is a bore, in particular a transverse bore. This is particularly easy to install later. In a preferred embodiment, the fuel nozzle assembly comprises four-quarter symmetrically arranged on a disc fuel nozzles. This disc is accordingly integrated in a customized recording unit of the essay. Essentially, the essay also includes four-eight outlets. Thus, according to the invention, therefore, a fuel nozzle assembly is provided which is integrated into an attachment and thus includes all outlets (atomizer nozzles). Thus, therefore, the fuel is divided into individual streams on its circumference. The number of nozzle inserts and receiving units arranged on the disk can vary, as can the arrangement of the nozzle inserts / receiving units on the disk.

Preferably, the nozzle insert and / or the receiving unit made of metal or a metal alloy. In a preferred embodiment, the nozzle insert and / or the receiving unit made of ceramic or ceramic material, since these materials are particularly abrasion resistant.

Preferably, the nozzle insert and / or the receiving unit are fine mechanical or with print technology produced. This production is particularly inexpensive and quick to implement.

Fig. 1

zeigt schematisch eine Gasturbine in einem Längsteilschnitt,

Fig. 2

zeigt schematisch einen Schnitt durch einen Brenner mit einer Düse nach dem Stand der Technik,

Fig. 3

zeigt schematisch einen erfindungsgemäßen Brennereinsatz,

Fig. 4,5

zeigt schematisch einen Aufsatz 13 mit 4 erfindungsgemäßen Brennereinsätzen in Rück- und Vorderansicht.

Further advantages, features and characteristics of the present invention will be described in more detail below on the basis of exemplary embodiments with reference to the attached figures. The features of the embodiments may be advantageous in this case individually or in combination with each other.

Fig. 1

shows schematically a gas turbine in a longitudinal partial section,

Fig. 2

shows schematically a section through a burner with a nozzle according to the prior art,

Fig. 3

shows schematically a burner insert according to the invention,

Fig. 4.5

schematically shows an attachment 13 with 4 burner inserts according to the invention in back and front view.

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS FIGS. 1 to 5 explained in more detail.

The FIG. 1 shows by way of example a gas turbine 100 in a longitudinal partial section.

The gas turbine 100 has inside a rotatably mounted about a rotation axis 102 rotor 103 with a shaft, which is also referred to as a turbine runner.

Along the rotor 103 successively follow an intake housing 104, a compressor 105, an example, toroidal combustion chamber 110 with a plurality of coaxially arranged burners 107, a turbine 108 and the exhaust housing 109th

The combustion chamber 110 communicates with an annular annular hot gas channel 111, for example. There, for example, four turbine stages 112 connected in series form the turbine 108.

Each turbine stage 112 is formed, for example, from two blade rings. In the flow direction of a working medium As can be seen in the hot gas duct 111 of a guide blade row 115, a row 125 formed of rotor blades 120 follows.

The guide vanes 130 are fastened to an inner housing 138 of a stator 143, whereas the moving blades 120 of a row 125 are attached to the rotor 103 by means of a turbine disk 133, for example.

Coupled to the rotor 103 is a generator or work machine (not shown).

During operation of the gas turbine 100, air 105 is sucked in and compressed by the compressor 105 through the intake housing 104. The compressed air provided at the turbine-side end of the compressor 105 is supplied to the burners 107 where it is mixed with a fuel. The mixture is then burned to form the working fluid 113 in the combustion chamber 110. From there, the working medium 113 flows along the hot gas channel 111 past the guide vanes 130 and the rotor blades 120. On the rotor blades 120, the working medium 113 expands in a pulse-transmitting manner so that the rotor blades 120 drive the rotor 103 and drive the machine coupled to it.

The FIG. 2 schematically shows a section through a burner 107 with a nozzle according to the prior art in a partially perspective view. The burner 107 can be used on the one hand in conjunction with the annular combustion chamber 106. Preferably, however, the burner 107 is used in conjunction with a so-called tube combustion chamber. In this case, instead of the annular combustion chamber 106, the gas turbine 100 has a plurality of annularly arranged tube combustion chambers whose downstream openings open into the annular hot gas channel 111 on the turbine inlet side. In this case, preferably at each of these tube combustion chamber a plurality, for example six or eight, burner 107 is arranged at the opposite end of the downstream opening of the tube combustion chamber usually annularly around a pilot burner.

The burner 107 comprises a cylindrical housing 12. In the housing 12, a lance with a fuel channel 16 is arranged along the central axis 27 of the burner 107. On the side of the lance leading to the combustion chamber 110, the latter comprises a pointed attachment 13, which is arranged concentrically to the central axis 27. In the article 13, the fuel nozzles 1 are arranged according to the prior art, which communicate with the fuel channel 16.

In the housing 12 of the burner 107, swirl vanes 17 are arranged around the lance. The swirl blades 17 are arranged along the circumference of the lance in the housing 12. Through the swirl blades 17, a compressor air flow 15 is passed into the combustion chamber 110 leading to the part of the burner 107. The air is displaced by the swirl blades 17 in a swirling motion. Fuel, for example oil, is injected through the fuel nozzles 1 into the resulting air stream. The resulting fuel-air mixture is then passed on to the combustion chamber 110.

The FIG. 3 schematically shows a section through a fuel nozzle according to the invention. The nozzle inserts 1 are arranged on the outer circumference of the attachment 13 in corresponding receiving units 4. A fuel nozzle arrangement comprises a plurality of, in the present exemplary embodiment, four nozzle inserts 1 according to the invention with corresponding receiving units 4 (FIG. FIG. 4 , Rear view and FIG. 5 Front View). The flow paths 5 are indicated as four slots ( FIG. 4, FIG. 5 ).

The central axis of the attachment 13 is indicated by the reference numeral 18. The attachment 13 is conical to the combustion chamber 110, tapered designed. The nozzle insert 1 is arranged on the outer circumference of the attachment 13 in the corresponding receiving units 4 and thus forms the swirl chambers 10. The nozzle insert 1 according to the invention is made as an integrated component. The nozzle insert according to the invention 1 includes at its fuel inlet 2, which is located in the swirl chamber 10 about a semicircular curved inlet beginning 7a and an end 7b. The nozzle insert 1 has a nozzle insert neck 3. The nozzle insert 1, in particular the nozzle insert neck 3 itself and the preferably circularly curved inlet beginning 7a, form with the receiving unit 4 a flow path 5, along which the fuel can flow. The entry start 7a and the end 7b form with the receiving unit 4, the swirl chamber 10 from. In this case, the flow path 5 which is formed by the inlet beginning 7a of the nozzle insert 1 and the receiving unit 4, taper in the flow direction or expand. In an extension of the flow path 5, the semicircular curved inlet beginning 7 a is bent substantially to an outlet 8 out. The fuel flowing through the flow path 5 is then deflected toward the center. In a taper, the inlet beginning 7a is bent away from the outlet and tapers the flow path 5 with it. The flow rate is increased. The increase can also take place in that the depth of the receiving unit 4 at the inlet beginning 7a changes in the flow direction, preferably reduced. In this case, a linear reduction or a non-linear reduction is possible. The swirl chamber 10 is formed substantially circular. The flow path 5 thus performs at the inlet beginning 7a in the swirl chamber 10 by this arrangement a circular movement, which directs the fuel towards the outlet 8. The fuel thus performs a circular movement, that is, the fuel is thus circular, in particular spiral 12 swirled. Subsequently, the so-swirled fuel passes through the outlet 8 for the purpose of atomization. In this case, the outlet 8 is a transverse bore for the purpose of outflow.

The nozzle insert 1 according to the invention thus generates a fuel flow in particular a liquid fuel flow with a swirl component in the chambers downstream.

With the solution according to the invention, a fuel nozzle is thus created by a nozzle insert 1 which can be integrated in a receiving unit 4. In particular, a disk with a fuel nozzle arrangement according to the invention is provided, which is inserted into an attachment 13 or another component and thus supplies all the outlets 8 (atomization openings) of the attachment 13. The fuel nozzle or the fuel nozzle arrangement divides the fuel flow into individual streams distributed over the circumference. The previously used nozzles are used for swirl generation in the flow of the fuel before it enters the combustion chamber. The twist is now generated by means of the special geometry of the fuel nozzle according to the invention. The fuel nozzle or the receiving unit and / or the nozzle insert can be made of metallic or ceramic materials fine mechanical or "print" -based.

Optionally, in the flow path 5, an acceleration of the fuel take place, so as to obtain maximum speed only at the entrance to the swirl chamber 10, so that too high pressure losses and cavitation are avoided and one thus obtains an effective nozzle cross section, which is more independent of the throughput. This can be achieved, for example, by bending the inlet beginning 7a to the outlet center 8 or bending it away from the outlet center 8 and / or by changing the depth of the receiving unit 4 at the entrance beginning 7a.

Claims (15)

1. Fuel nozzle for swirling a fuel/fuel-air mixture, comprising a holding unit (4) and a nozzle insert (1), with the nozzle insert (1) and the holding unit (4) embodying a flow path (5) and subsequently a swirl chamber (10), with the nozzle insert (1) having an inlet start (7a) and an end (7b), with the inlet start (7a) and the end (7b) being bent in a substantially circular manner so that an interrupted circle is formed, so that a fuel flowing into the swirl chamber (10) has a radially-inwards circular movement, especially a spiral movement (12) imparted to it, characterised in that a depth of the holding unit (4) reduces at the inlet start (7a) of the nozzle insert (1) in the flow direction, so that a change in the flow speed of the fuel is brought about.
2. Fuel nozzle according to claim 1,
   characterised in that the flow path (5) which is formed by the inlet start (7a) of the nozzle insert (1) and the holding unit (4), narrows in the direction of flow.
3. Fuel nozzle according to claim 1,
   characterised in that the flow path (5) which is formed by the inlet start (7a) of the nozzle insert (1) and the holding unit (4), widens in the direction of flow.
4. Fuel nozzle according to one of the preceding claims, characterised in that the nozzle insert (1) is able to be inserted as an integrated component into the holding unit (4).
5. Fuel nozzle according to one of the preceding claims, characterised in that the holding unit (4) and/or the nozzle insert (1) consist of metal or a metal alloy.
6. Fuel nozzle according to one of claims 1-4,
   characterised in that the holding unit (4) and/or the nozzle insert (1) consist of ceramics or ceramic material.
7. Fuel nozzle according to one of the preceding claims, characterised in that the holding unit (4) and/or the nozzle insert (1) is able to be manufactured using precision engineering or with print technology.
8. Fuel nozzle according to one of the preceding claims, characterised in that the swirl chamber (10) is embodied in a circular shape.
9. Fuel nozzle according to one of the preceding claims, characterised in that the swirl chamber (10) comprises an outlet (8) so that the fuel/fuel-air mixture can exit swirled at this point.
10. Fuel nozzle according to claim 9,
    characterised in that the outlet (8) is a hole.
11. Fuel nozzle arrangement,
    characterised in that this arrangement comprises four to eight fuel nozzles arranged symmetrically on a disc according to one of the preceding claims.
12. Burner (107) comprising at least one fuel nozzle arrangement according to claim 11.
13. Burner (107) according to claim 12,
    having a cylindrical housing (12) with a lance featuring a fuel duct (16) arranged centrally therein, which is supported on the housing via swirl blades (17) in a radial arrangement and on which an attachment (13) is arranged on a side leading into a combustion chamber, with the fuel nozzle arrangement being arranged in the attachment (13) preferably downstream from the swirl blades (17) and being connected in flow terms to the fuel duct (16).
14. Burner arrangement with a number of burners (107) arranged in the form of a ring around a central pilot burner, according to one of claims 12 to 13.
15. Gas turbine (100) having at least one burner (107) according to one of claims 12 to 13 or having a burner arrangement for each tubular combustion chamber according to claim 14.

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