EP1734306B1 - Burner for premix-type combustion - Google Patents

Abstract

The premix burner has a central cavity (8), into which premix air is fed through slots (11) in its walls. A central pipe (2) at the center of the cavity injects fuel for the main combustion into the burner, while pipes (14) above and below it on either side inject premix fuel (3) at right angles to the burner axis. An independent claim is included for a method for operating the burner.

Description

Technical application

The invention relates to a burner for premixing combustion according to claim 1 and a method for operating a burner according to claim 22.

State of the art

In view of ever stricter regulations for the emission of pollutants, great efforts are being made to create burners whose pollutant emissions, especially of nitrogen oxides, are low. A preferred arrangement are burners in the form of conical hollow body having tangential air inlet slots. Combustion air flows through the air inlet slots into the conical burner cavity. Via fuel outlet openings at the edges of the air inlet slots fuel, in particular gaseous fuel, is supplied to the combustion air flow. In addition, liquid fuel is introduced at the apex of the cone in the burner cavity, in particular sprayed. The combustion takes place at the exit of the conical burner cavity.

The EP 0 321 809 A1 describes a method for the premix-type combustion of liquid fuel, in which a conical liquid fuel column forms inside the conical cavity, which is enclosed by a rotating combustion air flow flowing tangentially into the burner. The ignition of the mixture takes place at the outlet of the burner, whereby a flame stabilization is established in the region of the burner mouth by the formation of a backflow zone. Also described is a corresponding burner, the two offset part cone body to form a conical burner cavity, a centrally between the mutually offset longitudinal axes of symmetry Part cone body attached fuel injection and having tangential air inlet slots. The fuel exit openings for introducing the premix fuel are attached to the edges of the air inlet slots. In order to achieve sufficient mixing of the premix fuel with the combustion air over the entire width of the air inlet slot, a high pressure for the injection of the premix fuel in the flowing at high speed combustion air flow is required. Since the injection takes place from one side of the air inlet slot and thus does not achieve homogenous mixing of the premix fuel with the combustion air over the entire width of the air inlet slot, optimum nitrogen emission values are not achieved.

The EP 0 981 016 B1 describes a burner, which also has the above-described conical structure with tangential air inlet slots for the introduction of a combustion air flow. This burner also has an injection device for injecting fuel into the combustion air flow. This injection device is arranged centrally in the combustion air flow in front of the air inlet slots in order to inject the fuel in a parallel flow direction to the combustion air flow.

The WO 01/96785 A1 describes a burner and a corresponding method for operating a burner, in which two or more fuel feeds are provided with arranged substantially in the direction of the burner axis fuel outlet openings, which can separately introduce premix fuel in the burner chamber. Thereby, a stepped injection of fuel into the burner chamber can be achieved, which adapts to the changing conditions in the operation of the burner, resulting for example from different loads, gas qualities or gas preheating temperatures.

The DE 100 49 205 A1 describes a method and apparatus for fueling a premix burner, in which the Premix fuel supply is performed over at least two spatially axially separate areas along the burner, so that for the startup of the turbine and for the further start-up of the load up to full load, a gradual or continuous redistribution of the supply of the premix fuel between the areas.

The US 5489203 describes a burner, which also has the above-described conical structure with tangential air inlet slots and a injection device for injecting fuel in the plane of the air inlet slots.

Presentation of the invention

The object of the present invention is therefore to propose a burner for premix-type combustion and a method for operating a burner, which enable a stable premix-type combustion with as homogeneous as possible mixing of the premix fuel with the combustion air with reduced pollutant emissions.

This object is achieved by a burner for premix-type combustion with the features of claim 1 and a method for operating a burner with the features of claim 22. Preferred embodiments of the invention will become apparent from the dependent claims.

An essential idea of the invention is that the means mounted centrally in the inflow region of the combustion air flow for injection of premix fuel into the tangential air inlet slots of a burner cavity are designed so that they relative to a cross-sectional plane perpendicular to the burner axis the premix fuel not only centrally but also more as a point in the combustion air flow to achieve the most homogeneous possible mixing of the premix fuel with the combustion air. Thus, a high pollutant emissions, in particular nitrogen oxides, avoided due to insufficient premixing.

Another idea of the invention is also that the fuel feeds are mounted in front of the air inlet slots with respect to the direction of the combustion air flow. Thus, they may be disposed in a region of a lower velocity of the combustion air flow than directly in the air inlet slots. Aerodynamic losses and the required pressure for the premix fuel injection can thus be reduced.

The invention now concretely relates to a burner for premix-type combustion, which has a cavity which has at least one tangential one An air inlet slot for supplying a combustion air flow, means for injecting fuel into the cavity, which are mounted in the region of a burner axis, and means for injection of premix fuel in the at least one air inlet slot, which are mounted centrally in the inflow region of the combustion air flow comprises. The means for injection of premix fuel in the at least one air inlet slots have at least one fuel supply, the fuel outlet openings are arranged such that the premix fuel is introduced on both sides of the at least one fuel supply relative to a cross-sectional plane perpendicular to the burner axis in the combustion air flow. Thus, a relatively homogeneous mixing of the premix fuel with the combustion air over the entire width of the air inlet slot and therefore improved nitrogen emissions can be achieved. In addition, the pressure for injecting the premix fuel into the relatively high velocity incoming combustion air stream can be reduced as compared to a one-sided injection from the edge of the air inlet slot.

Preferably, the burner is designed such that the cavity is formed from at least two complementary to a body cone bodies forming a conical cavity whose longitudinal axes of symmetry are radially offset from one another and include at least two tangential air inlet slots for the supply of a combustion air flow. Alternatively, the burner can be designed such that the cavity is formed from at least two complementary to a body body parts, which form a cylinder cavity whose longitudinal axes of symmetry are radially offset from one another and include at least two tangential air inlet slots for the supply of a combustion air flow. Likewise, tulip or cup-shaped formations of the cavity are possible.

In addition, the burner may have a mixing section located downstream of the cavity for transferring a flow generated in the cavity having a fuel mixture in a combustion chamber. This can increase the stability of flameless combustion.

In particular, the fuel outlet openings have a common, along the respective tangential air inlet slot mounted fuel supply. Among other things, the number of fuel feeds may depend on the number of air inlet slots, which in turn depends on whether the cavity is formed by two or more partial bodies.

In a preferred embodiment, the fuel outlet openings are formed as a pair of slot nozzles extending along the entire length of the fuel supply. Thus, the combustion air flow premix fuel can be supplied evenly distributed over the entire length of the tangential air inlet slot.

On the other hand, the fuel outlet openings may have circular or oval cross sections. By means of different opening diameters or passage cross sections, a different penetration depth of the premix fuel into the combustion air flow can be achieved so as to be able to realize different mixture distributions. In order to achieve a uniform distribution of the Vormischbrennstoffs over the entire length of the tangential air inlet slot, the fuel outlet openings can be distributed in pairs evenly over the entire length of the tangential air inlet slot. The arrangement, distribution and design of the fuel outlet openings affects the fuel distribution within the burner and thus its quality of combustion.

To a stepped introduction of Vormischbrennstoff in the combustion air flow and thus an optimized adjustment of the burner behavior when starting the example connected gas turbine or when operating in different load ranges permit, the fuel outlet openings may be arranged grouped such that a first group of fuel outlet openings distributed uniformly over the entire length of the tangential air inlet slot and having a first common fuel supply and that a second group of fuel outlet openings along a portion of the entire length of the tangential air inlet slot distributed and at least a second common fuel supply.

In another embodiment for the stepped introduction of premix fuel, the fuel outlets are arranged such that a first group of fuel outlets are evenly distributed over a first portion of the entire length of the tangential air entry slot and have a first common fuel supply and at least one second group is longitudinal a further portion of the entire length of the tangential air inlet slot distributed and having at least a second common fuel supply. Thus, a stepped supply of premix fuel may be advantageous when starting the gas turbine if the entire premix fuel supply is to take place preferably via the first, upstream group of fuel outlets. The premix fuel supply can be routed step by step or continuously to the second, downstream group of fuel outlets on further startup of the gas turbine to full load.

In a preferred embodiment of the burner, the subregions do not overlap. Depending on the operating mode of the burner, however, it may also be desirable for at least two partial areas to overlap.

In order to influence the degree of mixing of combustion air and premix fuel over the entire length of the tangential air inlet slot, the fuel outlet openings of two or more Groups have different cross-sections. Thus, the group of fuel outlets, which is to inject smaller amounts of premix fuel, have smaller injection cross-sections and vice versa.

In order to reduce the pressure loss during the inflow of the combustion air, the fuel feeds may have a streamlined profile with respect to a cross-sectional plane perpendicular to the burner axis.

In order to adapt the premix fuel supply to the operating mode of the burner or to the load conditions of, for example, a gas turbine, the fuel feeds may comprise means for regulating the mass flow of the premix fuel.

In particular, in one embodiment with a stepped premix fuel supply, it is advantageous that the fuel feeds to the groups of fuel outlet openings means for regulating the mass flow of Vormischbrennstoffs to independently impinge on them with fuel or the penetration depth of the premix fuel in the combustion air flow and thus the mixing quality influence. Under certain circumstances, it is even possible to dispense with the additional supply of a pilot fuel for starting the gas turbine or in low load operation in the central fuel injection at the burner axis.

Preferably, the means for injecting premix fuel in the air inlet slots are designed as a single component. Thus, when using another fuel, only the component for the Vormischbrennstoffzuführung be replaced, an exchange of the entire burner is then no longer necessary. It is also possible to retrofit other burners with such a device. For this purpose, the unitary component may comprise means for attachment to a burner. Such a construction can not only increase the flexibility in use of said burners, but also simplify the manufacture of the molded cone bodies, since the integration of the fuel feeds and the fuel outlets into the cast part cone body is eliminated.

In a further preferred embodiment of the burner, the means for injecting fuel into the cavity, which are mounted in the region of the burner axis, designed as a jet pipe, in addition to a central outlet nozzle for liquid fuel fuel outlet openings for the supply of premix fuel in a from the combustion chamber end remote Part of the beam tube along the burner axis having an associated fuel supply. In particular, jet nozzle applications that protrude into the cavity longer have proven to be advantageous in terms of combustion stability, as they may, for example, prevent undesirable interference between pilot fuel and premix fuel. In addition, can be dispensed with a device for blowing out the burner, for example, when switching off.

Alternatively, the means for injecting fuel into the cavity, which are mounted in the region of the burner axis, be designed as a conical body, the apex of which is oriented downstream and having a fuel outlet nozzle.

For additional stabilization and to reduce humming noises, the burner can be arranged together with a secondary burner as a hybrid burner.

The invention further relates to a method for operating a burner for a premix-type combustion, comprising a cavity having at least one tangential air inlet slot for supplying a combustion air flow, means for injecting at least one fuel via a lance into the cavity, and means for injecting at least one further fuel, said latter injection is in operative connection with the air inlet slot, wherein the means for injection of the latter fuel in the air inlet slot at least one fuel supply, the fuel outlet openings act such that the fuel on both sides of the fuel supply perpendicular or quasi-perpendicular to the burner axis in the Combustion air flow is introduced, wherein
the fuel supply is operated in relation to the direction of the combustion air flow in front of the air inlet slot.

The penetration depth and interference of the premix fuel jet may affect the mixing quality of the premix fuel and the combustion air and thus the fuel distribution at the burner throat. These in turn can be crucial for the combustion stability and the level of pollutant emissions, especially nitrogen emissions. In order to reduce aerodynamic losses and the required pressure for the premix fuel injection, the premix fuel is introduced in front of the air inlet slots with respect to the direction of the combustion air flow and thus in a lower velocity region of the combustion air flow than directly into the air inlet slots.

In particular, with such a method, gaseous fuels can be introduced into the combustion air flow on both sides of the fuel feeds, with reference to a cross-sectional plane perpendicular to the burner axis.

In order to achieve the most stable possible combustion in the region of the burner mouth, the premix fuel can be introduced uniformly over the entire length of the tangential air inlet slot. Good mixing of the fuels is the prerequisite for low levels of nitrogen oxide emissions during combustion in such premix burners.

On the other hand, to meet the different requirements for the burner, for example when starting a gas turbine or when operating at full load, the premix fuel can be introduced separately over at least two subregions of the entire length of the tangential air inlet slot. By controlling the premix fuel supply of a first portion in relation to at least a second portion, the burner can be operated stably even with a changed load or fuel quality with low nitrogen emission values.

Furthermore, the feed of the premix fuel to the individual fuel outlet openings can be carried out controllably. In particular, in the case of a stepped introduction of the premix fuel, it may be advantageous to carry out the supply of the premix fuel to the fuel outlet openings of the subregions in a load-dependent and independent manner. In addition, the premix fuel may also be introduced as a function of measured pressure fluctuations, pollutant emission values or material temperatures of the burner in order to ensure stable combustion.

In order to allow a radially from the jet pipe outwardly directed injection of Vormischbrennstoff into the cavity, the means for injecting fuel into the cavity, which are mounted in the region of the burner axis and are designed as a jet pipe, in addition to the introduction of a liquid fuel through a central Eject premix fuel via a portion of the jet pipe remote from the combustion chamber end along the burner axis. So can the Incorporation of the premix fuel in the cavity are even better graded and a better adaptation of the combustion to different operating conditions can be achieved.

Brief description of the drawings

Fig. 1

einen Längsquerschnitt eines kegelförmigen Brenners gemäß dem Stand der Technik;

Fig. 2

einen Querschnitt entlang der Linie A-A des in Fig. 1 dargestellten Brenners,

Fig. 3

einen Längsquerschnitt eines kegelförmigen Brenners mit den zentral im Zuströmungsbereich des Verbrennungsluftstroms angebrachten Mitteln zur Eindüsung von Vormischbrennstoff in die Lufteintrittsschlitze,

Fig. 4

einen Querschnitt entlang der Linie B-B des in Fig. 3 dargestellten Brenners,

Fig. 5

einen Längsquerschnitt eines kegelförmigen Brenners mit zwei Gruppen von Brennstoffaustrittsöffnungen, die sich längs zweier Teilbereiche der gesamten Länge des tangentialen Lufteintrittschlitzes verteilen,

Fig. 6

zwei Querschnitte entlang den Linien C-C und D-D des in Fig. 5 dargestellten Brenners, und

Fig. 7

einen Längsquerschnitt eines zylinderförmigen Brenners mit den zentral im Zuströmungsbereich des Verbrennungsluftstroms angebrachten Mitteln zur Eindüsung von Vormischbrennstoff in die Lufteintrittsschlitze.

The invention will be explained below with reference to exemplary embodiments in conjunction with the drawings. Show it:

Fig. 1

a longitudinal cross section of a conical burner according to the prior art;

Fig. 2

a cross section along the line AA of in Fig. 1 illustrated burner,

Fig. 3

a longitudinal cross section of a conical burner with the centrally mounted in the inflow region of the combustion air flow means for the injection of premix fuel in the air inlet slots,

Fig. 4

a cross section along the line BB of in Fig. 3 illustrated burner,

Fig. 5

a longitudinal cross section of a conical burner with two groups of fuel outlet openings, which are distributed along two portions of the entire length of the tangential air inlet slot,

Fig. 6

two cross sections along the lines CC and DD of the in Fig. 5 shown burner, and

Fig. 7

a longitudinal cross-section of a cylindrical burner with the centrally mounted in the inflow region of the combustion air flow means for the injection of premix fuel in the air inlet slots.

Ways to carry out the invention

Fig. 1 shows a longitudinal cross-section of a conical burner 1 according to the prior art, as shown for example in the EP 0 321 809 A1 is described. Related to it shows Fig. 2 a cross section along the line AA of in Fig. 1 illustrated burner. In the following, reference is made to both the Fig. 1 as well as the Fig. 2 Referenced.

The conical cavity 8 of the burner 1 is formed by two part cone bodies 7 displaced radially relative to one another. By the displacement of the longitudinal axes of symmetry 9 of the partial cone body 7 tangential air inlet slots 11 are formed, through which the mixed with Vormischbrennstoff 3 combustion air 12 flows into the conical cavity 8. The burner axis 10 is located centrally and on a line between the longitudinal axes of symmetry 9 of the part cone body 7. In the region of this burner axis 10, a jet pipe 2 is mounted to inject liquid fuel 4 into the burner chamber 8. In addition, for example, to ignite or stabilize the combustion, pilot fuel 6 is introduced into the conical cavity. Air is introduced to the shield 5 between the pilot fuel 6 and the liquid fuel 4 to prevent premature mixing of liquid fuel 4 and pilot fuel 6 and thus premature ignition of the fuels.

The liquid fuel 4 injected through the jet pipe 2 forms a conical fuel column which is surrounded by the rotating combustion air 12 mixed with premix fuel 3. The strength of the rotation depends on the design of the cone angle and the number and width of the air inlet slots 11. With a suitable selection of these parameters, the ignition of the fuel mixture takes place at the output of the burner 1, wherein in the region of the burner port 13, a flame stabilization by the Forming a backflow adjusts.

The fuel outlet openings 15 for introducing the premix fuel 3 are attached to the edges of the air inlet slots 11. To a sufficient mixing of the premix fuel 3 with the Achieve combustion air 12 over the entire width of the air inlet slot 11, a high pressure for the injection of the premix fuel 3 in the incoming at high velocity combustion air stream 12 is required. The injection occurs from one side of the air inlet slot 11. Thus, no homogenous mixing of the premix fuel with the combustion air over the entire width of the air inlet slot and therefore no optimal nitrogen emission values are achieved.

The fuel feeds 14, which are integrated in the partial cone bodies 7, are exposed to high thermal loads due to the contact on the one hand with cold fuel and on the other hand with hot combustion air, which can lead to a shorter service life of these components. Since the fuel feeds 14 and the fuel outlet openings 15 are an integral part of the cast part cone bodies 7, it is necessary to replace the entire burner 1 when using a different fuel. In addition, the integration of the fuel supply lines 14 and the fuel outlet openings 15 in the cast part cone body 7 is technically complex and expensive.

Fig. 3 shows a longitudinal cross section of a conical burner 1 with the centrally mounted in the inflow region of the combustion air stream 12 means for injection of premix fuel 3 in the air inlet slots 11th Fig. 4 shows a corresponding cross section along the line BB of FIG Fig. 3 illustrated burner. In the following, reference is made to both the Fig. 3 as well as the Fig. 4 Referenced.

Unlike the in Fig. 1 and Fig. 2 shown burner has the in Fig. 3 and Fig. 4 shown burner 1 fuel supply 14, which are not components of the partial cone body 7. They are designed as an independent component, which is arranged centrally in the inflow region of the combustion air flow 12. Furthermore, on both sides of the fuel supply 14 relative to a cross-sectional plane perpendicular to the burner axis 10 fuel outlet openings 15, the Introduce premix fuel 3 into the combustion air stream 12. The fuel outlet openings 15 have a circular cross-section. In other embodiments, the fuel exit openings may have oval or slot-shaped cross sections. By a suitable selection of the arrangement, size and number of the fuel outlet openings 15, the pollutant emission values, the flame backflow behavior and the flame stability can be influenced.

The fuel outlet openings 15 of a tangential air inlet slot 11 are supplied with premix fuel 3 via a common fuel feed 14. The fuel supply 14 may be provided with means which regulate the mass flow of the fuel in order to adapt it to the current operating conditions of the burner. The fuel supply 14 is arranged spatially in front of the air inlet slots 11, that is to say in a region of a lower velocity of the combustion air stream 12 than directly in the air inlet slots. This reduces aerodynamic losses and the required pressure for the injection of premix fuel 3. In addition, the fuel feeds 14 have a streamlined profile with respect to a cross-sectional plane perpendicular to the burner axis 10 in order to reduce the pressure loss during the inflow of the combustion air 12.

Since the premix fuel 3 is introduced into the combustion air flow 12 centrally and on both sides of the fuel feed 14, a relatively homogeneous mixing of premix fuel 3 and combustion air 12 results, which leads to combustion in the burner 1 with low nitrogen emissions.

By the execution of the premix fuel supply as an independent component, not the entire burner 1 must be replaced when using a different fuel, but only the component for the Vormischbrennstoffzuführung. It is also possible to retrofit other burners with such a device. Furthermore, the technical Producing the cast part cone body less expensive, since the integration of the fuel supply lines 14 and the fuel outlet openings 15 is omitted in the cast part cone body 7. The thermal load of the burner or the partial cone body, which occurs in the burner mentioned in the prior art due to the different temperatures of one hand, cold fuel and hot combustion air, decreases because the direct contact with the cold fuel supplying fuel supply is eliminated.

Fig. 5 shows a longitudinal cross-section of a conical burner 1 with two groups of fuel outlet openings 15.1, 15.2, which distribute along two partial areas 16, 17 of the entire length of the tangential air inlet slot 11. Related to this Fig. 6 two cross sections along the lines CC and DD of the in Fig. 5 illustrated burner. In the following, reference numerals both the Fig. 5 as well as the Fig. 6 Referenced.

The fuel supply of the tangential air inlet slot 11 shown here is divided into two separate fuel supply lines 14.1 and 14.2. In the first portion 16 of the entire length of the tangential air inlet slot 11 premix fuel 3 is introduced into the combustion air stream 12 through the fuel outlet openings 15.2, which is supplied via the fuel supply 14.2. Analogously, premix fuel 3 is introduced into the combustion air flow 12 in the second partial region 17 of the entire length of the air inlet slot 11 via the fuel outlet openings 15.1, which fuel is supplied via the fuel feed 14.1.

Such a gradual introduction of premix fuel 3 in the combustion air stream 12 allows an optimized adjustment of the burner behavior when starting the gas turbine, for example, or when operating in different load ranges. That's one Supply of premix fuel 3 in separate sections along the burner axis 10 advantageous when starting the gas turbine, if the entire premix fuel supply is preferably carried out in the upstream portion 16. The premix fuel supply can be laid stepwise or continuously to the downstream portion 17 during further startup of the gas turbine to full load. Means for regulating the mass flow of the premix fuel, which are not shown here, prove to be particularly advantageous in order to independently apply premix fuel 3 to the fuel feeds 14.1, 14.2 and to regulate the mass flow of premix fuel 3 within a fuel feed 14.1, 14.2.

In particular, with a stepped introduction of the premix fuel combustion oscillations are counteracted, which occur in the switching processes of a gas turbine and in turn lead to pressure fluctuations that affect the operation of the gas turbine. It may even be possible to rely on the supply of a pilot fuel for starting the gas turbine or in low load operation as in the description of Figures 1 and 2 mentioned to abstain. Furthermore, it is conceivable to use dry oil in the operation of a burner according to this invention.

Fig. 7 shows a longitudinal cross-section of a cylindrical UTC burner 1 (as burners of the company United Technologies Corporation are called, for example, one of these UTC burners is in the WO 93/17279 shown; the WO 93/17279 is hereby considered to be fully incorporated in the description) with a burner port 13 and the means centrally located in the inflow region of the combustion air stream for injecting premix fuel 3 into the air inlet slots 11. The means for injecting fuel 18 into the cavity of the burner 1 are as a conical body are executed, the apex of which is aligned downstream and a plurality of annularly arranged on the apex outlet nozzles 19 for the pilot fuel 6 has.

Again, the illustrated burner 1 fuel feeds 14, which are not components of the part cylinder body. They are designed as independent components which are arranged centrally in the inflow region of the combustion air flow, that is in the air inlet slots 11. The fuel feeds 14 have fuel outlet openings 15, which introduce the premix fuel 3 in the combustion air flow. The fuel outlet openings 15 have a circular cross-section. Alternatively, the fuel outlet openings may also have oval or slot-shaped cross sections.

The operation of the illustrated means for the injection of premix fuel in this UTC burner is analogous to the operation of these means in the in the FIGS. 3 to 6 illustrated burner with a conically shaped cavity. Likewise, all in the description of the FIGS. 3 to 6 mentioned embodiments of the means for injection of premix fuel to the UTC burner 1 applicable. It is also true that the various configurations of the premix fuel injection means are applicable to burners having a tulip or cup shaped cavity. Again, the operation of the means for injection of premix fuel analogous to the operation of these means in the in FIGS. 3 to 6 illustrated burner with a conically shaped cavity.

LIST OF REFERENCE NUMBERS

1

burner

2

lance

3

premix

4

liquid fuel

5

Air for shielding

6

pilot fuel

7

Partial conical bodies

8th

conical cavity

9

Longitudinal axis of symmetry of the partial cone body

10

Brenner

11

Air inlet slot

12

Combustion air flow

13

burner mouth

14

fuel supply

14.1

first common fuel supply

14.2

second common fuel supply

15

Fuel exit opening

15.1

Fuel outlet in the first part

15.2

Fuel outlet in the second part

16

first portion of the entire length of the tangential air inlet slot

17

second portion of the entire length of the tangential air inlet slot

18

conical means for injecting fuel into the cavity

19

Outlet nozzle for pilot fuel

Claims (30)

1. Burner (1) for premix-type combustion comprising a cavity (8) which has at least one tangential air inlet slot (11) for the supply of a combustion air flow (12), means (2) for the injection via a lance (2) of at least one fuel (4, 6) into the cavity (8), and means for the injection of at least one further fuel (3), the latter injection being actively connected to the air inlet slot (11), the means for the injection of the latter fuel (3) into the air inlet slot (11) having at least one fuel supply (14), the fuel outlet openings (15) of which are arranged in such a way that the fuel (3) is introduced into the combustion air flow (12) on both sides of the fuel supply (14) at right angles or almost at right angles to the burner axis (10), characterized in that the fuel supply (14) is provided in front of the air inlet slot (11) in relation to the direction of the combustion air flow (12).
2. Burner according to Claim 1, characterized in that the cavity (8) is formed by at least two part cone bodies (7) which complement one another to form a body, which form a cone cavity and the longitudinal axes of symmetry (9) of which are offset radially in relation to one another and enclose at least two tangential air inlet slots (11) for the supply of a combustion air flow (12).
3. Burner according to Claim 1, characterized in that the cavity (8) is formed by at least two part cylinder bodies (7) which complement one another to form a body, which form a cylinder cavity and the longitudinal axes of symmetry (9) of which are offset radially in relation to one another and enclose at least two tangential air inlet slots (11) for the supply of a combustion air flow (12).
4. Burner according to one of the preceding claims, characterized in that a mixing section for transferring a flow of a fuel mixture generated in the cavity (8) into a combustion chamber is arranged downstream of the cavity (8).
5. Burner according to one of the preceding claims, characterized in that the fuel outlet openings (15) have a common fuel supply (14) provided along the respective tangential air inlet slot (11).
6. Burner according to Claim 5, characterized in that the fuel outlet openings (15) are designed as a pair of slit nozzles extending longitudinally over the entire length of the fuel supply (14).
7. Burner according to one of Claims 1 to 5, characterized in that the fuel outlet openings (15) have circular or oval cross sections.
8. Burner according to one of Claims 1 to 5 or 7, characterized in that the fuel outlet openings (15) are distributed in pairs uniformly over the entire length of the tangential air inlet slot (11).
9. Burner according to one of the preceding claims, characterized in that the fuel outlet openings (15) are arranged in a grouped manner in such a way that a first group of fuel outlet openings is distributed uniformly over the entire length of the tangential air inlet slot (11) and has a first common fuel supply and in that a second group of fuel outlet openings is distributed along a part region of the overall length of the tangential air inlet slot (11) and has at least one second common fuel supply.
10. Burner according to one of Claims 1 to 7, characterized in that the fuel outlet openings (15) are arranged in a grouped manner in such a way that a first group of fuel outlet openings (15.1) is distributed uniformly over a first part region (17) of the overall length of the tangential air inlet slot (11) and has a first common fuel supply (14.1) and in that at least one second group of fuel outlet openings (15.2) is distributed along a further part region (16) of the overall length of the tangential air inlet slot (11) and has at least one second common fuel supply (14.2).
11. Burner according to Claim 9 or 10, characterized in that the part regions (16, 17) do not overlap.
12. Burner according to Claim 9 or 10, characterized in that at least two part regions overlap.
13. Burner according to one of Claims 9 to 12, characterized in that the fuel outlet openings (15) of two or more groups of fuel outlet openings (15.1, 15.2) have different cross sections.
14. Burner according to one of the preceding claims, characterized in that the fuel supplies (14) have a streamlined profile related to a cross sectional plane at right angles to the burner axis (10).
15. Burner according to one of the preceding claims, characterized in that the fuel supplies (14) have means for regulating the mass flow of the premix fuel.
16. Burner according to one of Claims 9 to 13, characterized in that the fuel supplies (14.1, 14.2) to the groups of fuel outlet openings (15.1, 15.2) have means for regulating the mass flow of the premix fuel (3) in order to admit fuel to them independently of one another.
17. Burner according to one of the preceding claims, characterized in that the means for the injection of premix fuel (3) into the air inlet slots are embodied as a standard component.
18. Burner according to Claim 17, characterized in that the standard component has means for fastening to a burner (1).
19. Burner according to one of the preceding claims, characterized in that the means for the injection of fuel into the cavity which are provided in the region of the burner axis (10) are embodied as a jet pipe (2) which, in addition to a central outlet nozzle for liquid fuel (4), has fuel outlet openings for the supply of premix fuel in a part region of the jet pipe (2) along the burner axis (10) remote from the end on the combustion-space side with an associated fuel supply.
20. Burner according to one of Claims 1 to 19, characterized in that the means (18) for the injection of fuel into the cavity which are provided in the region of the burner axis (10) are embodied as a conical body, the cone tip of which is aligned downstream and has an outlet nozzle (19) for fuel.
21. Burner according to one of the preceding claims, characterized in that it is arranged together with a secondary burner.
22. Method for operating a burner (1) for a premix-type combustion, comprising a cavity (8) which has at least one tangential air inlet slot (11) for the supply of a combustion air flow (12), means (2) for the injection via a lance (2) of at least one fuel (4, 6) into the cavity (8), and means for the injection of at least one further fuel (3), the latter injection being actively connected to the air inlet slot (11), the means for the injection of the latter fuel (3) into the air inlet slot (11) having at least one fuel supply (14), the fuel outlet openings (15) of which act in such a way that the fuel (3) is introduced into the combustion air flow (12) on both sides of the fuel supply (14) at right angles or almost at right angles to the burner axis (10),
    characterized in that the fuel supply (14) is operated in front of the air inlet slot (11) in relation to the direction of the combustion air flow (12).
23. Method according to Claim 22, characterized in that a gaseous fuel is introduced into the combustion air flow (12) on both sides of the fuel supplies (14) related to a cross-sectional plane at right angles to the burner axis (10).
24. Method according to Claim 22 or 23, characterized in that the premix fuel (3) is introduced uniformly over the entire length of the tangential air inlet slot (11).
25. Method according to Claim 22 or 23, characterized in that the premix fuel (3) is introduced separately via at least two part regions (16, 17) of the overall length of the tangential air inlet slot (11).
26. Method according to one of Claims 22 to 25, characterized in that premix fuel (3) is introduced in front of the air inlet slots (11) related to the direction of the combustion air flow (12).
27. Method according to one of Claims 22 to 26, characterized in that the supply of the premix fuel (3) to the individual fuel outlet openings (15) is carried out adjustably.
28. Method according to Claim 25, characterized in that the supply of the premix fuel (3) to the fuel outlet openings (15.1, 15.2) of the part regions (16, 17) is carried out independently of one another.
29. Method according to Claim 28, characterized in that the supply of the premix fuel (3) to the fuel outlet openings (15.1, 15.2) of the part regions (16, 17) is carried out load-dependently.
30. Method according to one of Claims 22 to 29, characterized in that the means (2) for the injection of fuel into the cavity (8) which are provided in the region of the burner axis (10) and embodied as a jet pipe, in addition to introducing liquid fuel (4) through a central outlet nozzle, introduce premix fuel via a part region of the jet pipe (2) along the burner axis (10) remote from the end on the combustion-space side.

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