EP0794383A2 - Pressurised atomising nozzle - Google Patents

Abstract

The swirl chamber (39) is connected with an outer chamber by a nozzle hole (33) and has at least one inflow duct (41) for the liquid being atomised. The liquid is conveyed under pressure through the first inflow duct. The chamber contains at least one further inflow duct (38) for part of the liquid (37) being atomised or for a second liquid being atomised. Either or both liquids is/are conveyed under pressure and while swirling through the second inflow duct. The nozzle hole is in the cover (32) of a first pipe in which a smaller diameter second pipe (35) fits. The annular gap (36) between the pipes acts an inflow for a swirl stage. The second pipe is bounded by a filler piece (40)containing at least one tangential swirl duct. At least one inflow duct (41) acts as turbulence duct.

Description

Technical field

The invention relates to the field of combustion technology. It relates to a pressure atomizing nozzle, comprising a nozzle body, in which a turbulence or swirl chamber is formed, which is connected to an outside space via a nozzle bore and has at least one supply channel for the liquid to be atomized, through which said liquid can be supplied under pressure, and a method of operating this pressure atomizing nozzle.

State of the art

Atomizer burners are known in which the oil which is burned is finely divided mechanically. It is broken down into fine droplets of approximately 10 to 400 µm in diameter (oil mist), which evaporate and burn in the flame when mixed with the combustion air. In pressure atomizers (see Lueger - Lexikon der Technik, Deutsche Verlags-Anstalt Stuttgart, 1965, Volume 7, p.600), the oil is supplied to an atomizer nozzle under high pressure by an oil pump. The oil enters a swirl chamber via essentially tangential slots and leaves the nozzle via a nozzle bore. It is thereby achieved that the oil particles receive two components of motion, an axial and a radial. The oil film emerging from the nozzle bore as a rotating hollow cylinder widens into a hollow cone due to the centrifugal force whose edges start to vibrate unstably and tear into small oil droplets. The atomized oil forms a cone with a more or less large opening angle.

• 1. Die Tröpfchengrösse muss gering sein, damit die Öltröpfchen vor der Verbrennung vollständig verdampfen können.
• 2. Der Öffnungswinkel (Ausbreitungswinkel) des Ölnebels soll insbesondere bei der Verbrennung unter erhöhtem Druck klein sein.
• 3. Die Tropfen müssen eine hohe Geschwindigkeit und einen hohen Impuls haben, um weit genug in den verdichteten Verbrennungsluftmassenstrom eindringen zu können, damit sich der Brennstoffdampf vollständig mit der Verbrennungsluft vor Erreichen der Flammenfront vormischen kann.

In the low-pollutant combustion of mineral fuels in modern burners, for example in premix burners of the double-cone type, which are described in their basic structure in EP 0 321 809 B1, special requirements are placed on the atomization of the liquid fuel. The main ones are:

• 1. The droplet size must be small so that the oil droplets can evaporate completely before combustion.
• 2. The opening angle (angle of spread) of the oil mist should be small, especially when burning under increased pressure.
• 3. The drops must have a high speed and a high momentum in order to be able to penetrate far enough into the compressed combustion air mass flow so that the fuel vapor can completely premix with the combustion air before reaching the flame front.

Swirl nozzles (pressure atomizers) and air-assisted atomizers of the known types with a pressure of up to approx. 100 bar are hardly suitable for this because they do not allow a small angle of propagation, the atomization quality is restricted and the impulse of the drop spray is low.

As a result of this inadequate evaporation and premixing of the fuel, it is therefore necessary to add water to lower the flame temperature locally and thus NOx formation. Since the supplied water often also interferes with flame zones, which in themselves generate little NOx, but are very important for flame stability, instabilities such as flame pulsation and / or poor burnout often occur, which leads to an increase in CO emissions.

An improvement can be achieved with the high-pressure atomizing nozzle known from EP 0 496 016 B1. This consists of a nozzle body, in which a turbulence chamber is formed, which is connected to an outside space via at least one nozzle bore, and which has at least one supply channel for the liquid to be atomized, which can be supplied under pressure. It is characterized in that the cross-sectional area of the feed channel opening into the turbulence chamber is larger by a factor of 2 to 10 than the cross-sectional area of the nozzle bore. This arrangement makes it possible to generate a high level of turbulence in the turbulence chamber, which does not subside on the way to the point of exit from the nozzle. The fluid jet is caused to decay rapidly by the turbulence generated in front of the nozzle bore in the outside space, that is to say after leaving the nozzle bore, resulting in low angles of propagation of 20 ° and less. The droplet size is also very small.

When operating gas turbine burners with liquid fuel, the aim is to generate a drop spray over the entire load range of the gas turbine (approx. 10% to 120% fuel mass flow based on nominal load conditions), which enables stable, low-pollution combustion in a given air flow field .

The use of a high-pressure atomizer nozzle as described above for atomizing liquid fuel in gas turbine burners, as desired, does not lead to a too high pressure (100 bar) and a small droplet size under full load and overload (100 bar), with undesirable wall wetting and coking due to the narrow spray angle be avoided.

At partial load, however, the fuel admission pressure drops due to the falling total fuel mass flow. However, the energy required for atomization for pressure atomizers is over given the fuel admission pressure, so that the atomization quality worsens in this load range and the penetration depth of the fuel spray into the air flow becomes smaller due to the low fuel admission pressure.

Presentation of the invention

The invention tries to avoid all of these disadvantages. It is based on the task of developing a pressure atomizing nozzle which has a simple construction, requires only a small installation space and enables a spray angle of the liquid to be atomized which is adapted to the respective operating conditions. When using this pressure atomizing nozzle in a gas turbine burner, a sufficiently large nozzle admission pressure should be generated even with small fuel mass flows (approx. 25% based on nominal load conditions), while the nozzle with a large fuel mass flow (approx. 100-120% based on nominal load conditions) should not generate an excessively high nozzle admission pressure should need. The drop spray produced in this way is intended to enable low-pollutant and stable combustion over the entire load range of the gas turbine.

According to the invention, this is the case with a pressure atomizing nozzle, comprising a nozzle body, in which a turbulence and / or swirl chamber is formed, which is connected to an outside space via a nozzle bore and has at least one first feed channel for the liquid to be atomized, through which said liquid is submerged Pressure can be supplied, in that at least one further supply channel for part of the liquid to be atomized or for a second liquid to be atomized opens into the chamber, through which said part of the liquid or the second liquid can be supplied under pressure and with swirl .

The advantages of the invention are, inter alia, that this two-stage pressure atomizing nozzle enables adaptation of the pot spray (atomization quality, drop size, spray angle) to the respective load conditions. Furthermore, the nozzle is characterized by a simple design that takes up little space.

It is particularly expedient if the pressure atomizing nozzle is designed in such a way that the liquid to be atomized can be fed into the chamber via the first supply channel (s) without any swirl. The main atomizer stage thus consists of a swirl-free, turbulence-assisted pressure atomizer nozzle which, at high nozzle admission pressures, for example 100 bar, delivers very fine atomization with extremely small spray angles. By combining this turbulence atomizer stage with the swirl stage described above, in which small drops are generated at low throughputs, the atomization can be adapted well to the respective operating conditions. The part of the liquid to be atomized brought into the chamber through the swirl channels rotates in the chamber. The rotating movement creates a hollow cone flow at the nozzle hole, so that the liquid only exits the nozzle as a film from a certain mass fraction that is supplied by the swirl stage. If the mass fraction of the swirl stage is increased with falling total liquid mass flow, the liquid admission pressure can be kept at a high level, so that fine atomization can be maintained even with a low mass flow. The liquid spray cone angle is larger at low load, this compensates for the lower penetration depth of the liquid spray into the air flow. Since a very small spray cone angle is desired at full load and overload, the liquid mass flow to be atomized flowing through the swirl channels is reduced or completely switched off in these cases.

Furthermore, it is advantageous if, in the pressure atomizing nozzle according to the invention, the liquid to be atomized can be fed into the chamber via the first feed channel (s) with swirling action. This forms a two-stage pressure swirl atomizer nozzle in which the two stages are brought together in a common chamber, which is a swirl chamber here. If the liquid to be atomized is now led into the main swirl stage with a small swirl, a narrow spray angle of the liquid to be atomized is achieved.

If the pressure atomizer nozzle is operated at full and overload operation via a main pressure swirl stage with a low swirl, by swirling the entire liquid to be atomized via at least one first supply channel to the swirl chamber, where a swirled flow is generated which then passes through the nozzle bore into the outside space , and in partial and low-load operation it is additionally operated via a further pressure swirl stage with a larger swirl, in that part of the liquid to be atomized or a second liquid to be atomized is more swirled through the at least one further supply channel and there is a strongly swirled flow is generated, which then passes through the nozzle bore into the outside space, the proportion of the more swirled liquid supplied via the further swirl stage being increased as the total liquid mass flow decreases, this can be done e way an excellent adaptation of the atomization to the respective load range.

It is advantageous to switch smoothly between the two stages and, depending on the load conditions, to operate the nozzle with only one of the two stages.

Advantageous configurations of the pressure atomizing nozzle according to the invention are described in the subclaims.

Finally, the nozzle according to the invention is advantageously used in a premix burner of the double-cone design or in a four-slot burner, part of the combustion air (approx. 3 to 7%) being conducted in the jacket flow around the nozzle in the vicinity of the nozzle. This avoids local detachment and recirculation areas. The recirculation zone is prevented from moving into the interior of the burner.

Brief description of the drawing

Several exemplary embodiments of the invention are shown in the drawing.

Fig. 1

einen Teillängsschnitt einer Druckzerstäuberdüse mit Turbulenzstufe und Drallstufe;

Fig. 2

einen Querschnitt der Druckzerstäuberdüse nach Fig. 1 im Bereich der Turbulenzstufe entlang der Linie II-II;

Fig. 3

einen Querschnitt der Druckzerstäuberdüse nach Fig. 1 im Bereich der Drallstufe entlang der Linie III-III;

Fig. 4

einen Teillängsschnitt einer Druckzerstäuberdüse mit zwei Drallstufen;

Fig. 5

einen Querschnitt der Druckzerstäuberdüse nach Fig. 4 im Bereich der Drallhauptstufe entlang der Linie V-V;

Fig. 6

einen Querschnitt der Druckzerstäuberdüse nach Fig. 4 im Bereich der weiteren Drallstufe entlang der Linie VI-VI;

Fig. 7

einen Teillängsschnitt einer Druckzerstäuberdüse wie in Fig. 1 in einer anderen Ausführungsvariante;

Fig. 8

eine schematische Darstellung des Flüssigkeitszufuhrsystems zur zweistufigen Druckzerstäuberdüse, wobei in beiden Stufen Öl zerstäubt wird;

Fig. 9

eine schematische Darstellung des Flüssigkeitszufuhrsystems zur zweistufigen Druckzerstäuberdüse, wobei in beiden Stufen jeweils unterschiedliche Flüssigkeiten(Öl, Wasser) zerstäubt werden;

Fig. 10

eine schematische Darstellung der Massenstromverteilung für eine Düse gemäss Fig. 1;

Fig. 11

eine schematische Darstellung der Massenstromverteilung für eine Düse gemäss Fig. 4;

Fig. 12

einen Vormischbrenner der Doppelkegelbauart in perspektivischer Darstellung

Fig. 13

einen vereinfacht dargestellten Schnitt in der Ebene XIII-XIII gemäss Fig. 12;

Fig. 14

einen vereinfacht dargestellten Schnitt in der Ebene XIV-XIV gemäss Fig. 12;

Fig. 15

einen vereinfacht dargestellten Schnitt in der Ebene XV-XV gemäss Fig. 12;

Fig. 16

eine schematische Ansicht eines Doppelkegelbrenners mit Mantelluftstromführung im Düsennahbereich;

Fig. 17

eine schematische Ansicht eines Vierschlitzbrenners mit Mantelluftstromführung im Düsennahbereich.

Show it:

Fig. 1

a partial longitudinal section of a pressure atomizing nozzle with turbulence stage and swirl stage;

Fig. 2

a cross section of the pressure atomizing nozzle of Figure 1 in the region of the turbulence stage along the line II-II.

Fig. 3

a cross section of the pressure atomizing nozzle of Figure 1 in the region of the swirl stage along the line III-III.

Fig. 4

a partial longitudinal section of a pressure atomizing nozzle with two swirl stages;

Fig. 5

a cross section of the pressure atomizing nozzle of Figure 4 in the region of the main swirl stage along the line VV.

Fig. 6

a cross section of the pressure atomizing nozzle according to Figure 4 in the region of the further swirl stage along the line VI-VI.

Fig. 7

a partial longitudinal section of a pressure atomizing nozzle as in Figure 1 in another embodiment.

Fig. 8

a schematic representation of the liquid supply system to the two-stage pressure atomizing nozzle, with oil being atomized in both stages;

Fig. 9

is a schematic representation of the liquid supply system for the two-stage pressure atomizing nozzle, different liquids (oil, water) being atomized in each of the two stages;

Fig. 10

a schematic representation of the mass flow distribution for a nozzle according to FIG. 1;

Fig. 11

a schematic representation of the mass flow distribution for a nozzle according to FIG. 4;

Fig. 12

a premix burner of the double cone type in perspective

Fig. 13

a simplified section in the plane XIII-XIII of FIG. 12;

Fig. 14

a simplified section in the plane XIV-XIV of FIG. 12;

Fig. 15

a simplified section in the plane XV-XV of FIG. 12;

Fig. 16

a schematic view of a double cone burner with jacket air flow in the vicinity of the nozzle;

Fig. 17

is a schematic view of a four-slot burner with jacket air flow in the vicinity of the nozzle.

Only the elements essential for understanding the invention are shown. Identical elements are provided with the same reference symbols in the various figures. The direction of flow of the media is indicated by arrows.

Way of carrying out the invention

The invention is explained in more detail below with reference to several exemplary embodiments and FIGS. 1 to 16.

1 to 3 show a first exemplary embodiment of the invention, FIG. 1 showing the pressure atomizing nozzle in a partial longitudinal section and FIGS. 2 and 3 showing two cross sections in different planes.

The pressure atomizing nozzle comprises a nozzle body 30, consisting of a first tube 31, which is closed at its end seen in the direction of flow by a conical cover 32. In the middle of the cover 32 there is a nozzle bore 33, the longitudinal axis of which is designated by 34. A second tube 35, which has a smaller outside diameter than the inside diameter of the first tube 31, is inserted into the tube 31 and extends as far as the cover 32 and rests thereon. The annular space 36 between the two tubes 31 and 35 serves to supply the or a part of the liquid 37 to be atomized. The end of the tube 35 resting on the cover 32 is provided with four tangentially arranged slots 38 which connect the annular space 36 to produce a chamber 39 which serves as a swirl chamber for the liquid 37 to be atomized flowing through the slots 38. The chamber 39 is delimited by the inner walls of the cover 32 and the second tube 35, and by a filler 40 which is inserted in the interior of the second tube 35 and fastened therein. This filler 40 is spaced from the top edge of the slots 38, however, it can also be at the same height in another embodiment variant. Four feed channels 41 for the liquid 37 to be atomized are arranged in the filler 40, which enable a swirl-free inflow of the liquid 37 into the chamber 39, so that the chamber 39 serves as a turbulence chamber in this case. The pressure atomizing nozzle according to the invention thus has two stages - a turbulence generator stage (see FIG. 2) and a pressure swirl stage (see FIG. 3).

In a departure from the exemplary embodiment shown, the pressure atomizing nozzle can also be provided with more or fewer slots 38 or feed channels 41. For example, the feed channel 41 can extend over the entire circumference of the filler 40, so that an annular gap results as a feed channel into the turbulence chamber 39. A different distribution of the channels over the circumference is also possible.

4 to 6 show a further exemplary embodiment of the invention, FIG. 4 showing the pressure atomizing nozzle according to the invention in a partial longitudinal section and FIGS. 5 and 6 showing two cross sections in different planes.

The structure of the nozzle differs from the exemplary embodiment described above only in that a swirl main stage is present in the nozzle instead of the turbulence generator stage. For this purpose, the supply channels 41a, in contrast to the supply channels 41 in FIG. 1, are not arranged axially aligned in the filler 40, but are positioned tangentially, so that the liquid 37 to be atomized swirls in both via the channels 38 and via the channels 41a the chamber 39 arrives. It is important that the liquid 37 to be atomized receives only a small swirl, which leads to a narrow spray cone angle φ, when it has flowed through the channels 41a, while the swirl of the liquid 37 is greater after flowing through the channels 38 and thus a larger one Spray cone angle φ is achievable. 4 shows that the nozzle is acted upon by two liquids 37 and 37 'to be atomized. Both liquids 37, 37 'are swirled to the chamber 39, which in this case is a pure swirl chamber, the liquid 37 being less swirled than the liquid 37'. Due to the different swirl, the spray cone angle φ and thus the distribution of the liquid mass flow after the nozzle can be influenced.

7 shows a further embodiment variant of a two-stage pressure atomizer nozzle according to the invention with a turbulence generator stage and a swirl stage. The pressure atomizing nozzle comprises a nozzle body 30, consisting of a first tube 31, which is closed at its end seen in the direction of flow by a conical cover 32. In turn, the nozzle bore 33 is arranged in the cover 32. In the first tube 31, a second tube 35 is inserted, which has a smaller outside diameter than the inside diameter of the first tube 31, so that an annular channel 36 is formed between the tubes 31 and 35, which according to FIG. 7 has a different height due to different inserts can have. This ring channel 36 serves as a feed line for a swirl stage. The second tube 35 is delimited by a filler 40 of larger diameter, which encloses the chamber 39 with the cover 32 of the first tube 31. At least one tangential swirl channel 38 for connecting the ring channel 36 to the chamber 39 is arranged in the filler 40. For example, 6 channels 38 are advantageous. In the second tube 35 and in the filler 40, at least one feed channel 41 is also arranged axially parallel as a turbulence channel for the liquid to be atomized, the feed channel / feed channels 41 opening into the swirl channel / swirl channels 38.

Of course, it is also possible to arrange the channels 38 and 41 so that, for example, the swirl channels 38 into the Open channels 41, so that the liquid to be atomized only enters the chamber 39 via the channels 41.

Fig. 8 shows a schematic representation of a possible liquid supply system to the pressure atomizing nozzle. The liquid to be atomized, in this case liquid fuel (oil) 12, is pumped into a pressure container 43 via a pump 42. A return valve 49 is used to set the pump admission pressure. A shut-off valve 50 is arranged in the fuel line between the pump 42 and the pressure vessel 43. Two lines 44, 45 extend from the pressure vessel 43, the line 44 feeding the annular space 36 (and thus the swirl atomizer stage) and the line 45 being connected to the feed channels 41 (turbulence generator stage) or 41a (swirl atomizer stage). A control valve 46 and 47 is arranged in each of the lines 44 and 45, which allow the respective amount of liquid supplied to be regulated. Depending on requirements, one of the two valves 46, 47 can also be completely closed, so that in this case only one of the two atomizing stages of the nozzle is in operation. Smooth switching is possible between the two stages. As indicated in FIG. 8, several burners, for example a gas turbine combustion chamber, are to be supplied with fuel via this fuel supply system. The circuit shown has the advantage that only the two valves 46, 47, i.e. only one control valve per stage.

Another embodiment variant analogous to FIG. 8 is shown in FIG. 9. In this case, the pressure atomizing nozzle is fed with water 51 via a feed line 44 and with oil 12 via a feed line 45. A pump 42 is arranged in each of the lines 44 and 45 and a shut-off valve 50 is arranged downstream, with which the lines 44 and 45 can optionally be closed. The amount of the liquids 12, 51 to be atomized is regulated by means of the control valves 46, 47. If, as indicated in FIG. 9, several burners, for example a gas turbine combustion chamber, are supplied with liquid fuel 12 or water 51 via this liquid supply system, then the nozzle can be operated at the start or at partial load by only atomizing oil 12 finely via the main swirl stage . The swirl stage can be designed for maximum pressure at maximum fuel mass flow ṁ _BS . At higher loads or full loads, water 51 is then supplied via line 44. Water 51 and oil 12 mix in chamber 39 and form an emulsion which is atomized when it emerges from the nozzle. This leads to a reduction in NOx emissions. Here, too, there is an advantage that only one control valve is required per atomizer stage, that only one oil line is necessary for gas turbine operation, and that the swirl stage can be designed for pure oil operation, since the supply of water 51 through line 44 increases the Total mass flow at the same pressure leads.

FIG. 10 shows the distribution of the fuel mass flow in _BS as a function of the radius R of the spray in a pressure atomizer nozzle according to the embodiment variant shown in FIG. 1 at a certain distance from the nozzle. If only the turbulence-generating stage is operated, a very narrow spray cone angle φ is achieved. If, on the other hand, only the swirl generator stage is operated, this has an effect in a larger spray cone angle φ. With the combined operation of both stages, the mass distribution between the two stages can be varied continuously.

FIG. 11 shows the distribution of the fuel mass flow in _BS as a function of the radius R of the spray in a pressure atomizer nozzle according to the embodiment variant shown in FIG. 4 at a certain distance from the nozzle. Combined operation of the two with different spray cone angles φ working swirl stages, the mass flow distribution between the two stages can also be varied.

The pressure atomizing nozzle according to the invention can, for example, be installed in a gas turbine burner and operated as follows:

First, a pressure atomizer nozzle is to be used in an embodiment variant according to FIG. 1. Since a very narrow spray cone angle φ is desired for full load and overload, only the turbulence-assisted atomizer stage is used. For this purpose, the entire fuel mass flow to be atomized is supplied without swirl to the turbulence chamber 39 via at least one feed channel 41 (four feed channels 41 according to FIG. 1), a highly turbulent flow being generated there, which then passes through the nozzle bore 33 into the burner. This main stage delivers a very fine atomization with an extremely narrow spray cone angle φ (approx. 20 °) at nozzle admission pressures of approx. 100 bar. In partial and low-load operation, this turbulence-assisted pressure atomizer stage is combined with a swirl stage for the generation of small drops at low throughputs. For this purpose, part of the fuel to be atomized is swirled into the chamber 30 via at least one further feed channel 38 (four feed channels 38 according to FIG. 1), so that the turbulence chamber 30 is additionally used as a swirl chamber. The rotating movement creates a hollow cone flow at the nozzle bore 33. From a certain mass fraction that is passed through the swirl stage, the fuel only emerges as a film from the nozzle. If the proportion of the fuel mass flow through the swirl stage is increased with a falling total fuel mass flow, the fuel admission pressure can be kept at a high level (> 10 bar) and fine atomization can be maintained even with a low mass flow. In addition, the spray cone angle becomes low load φ enlarged. Since the depth of penetration of the fuel spray into the air flow is lower at low load than at full load, this is compensated for by the larger spray cone angle φ. A very narrow spray cone angle φ is desirable for full load and overload. For this purpose, the fuel mass flow flowing through the swirl channels 38 must be switched off completely, so that the behavior of a pure turbulence-assisted pressure atomizer nozzle is achieved.

If a pressure atomizer nozzle according to FIG. 4 is used, then during full and overload operation of the gas turbine, the entire fuel to be atomized is fed to the swirl chamber 39 with a small swirl via at least one first feed channel 41a (four feed channels 41a according to FIG. 4), one swirling there Flow is generated, which then passes through the nozzle bore 33 into the outside space. Due to the low swirl, a narrow spray cone angle φ is achieved, which leads to fine atomization of the fuel at high pressures. In partial and low-load operation, part of the fuel to be atomized is additionally swirled to the chamber 39 via the at least one further feed channel 38 (four feed channels 38 according to FIG. 4). As a result, a more swirled flow is generated in the chamber 39, which then passes through the nozzle bore 33 into the outside space, the proportion of the more swirled fuel mass flow supplied via the further swirl stage being increased with a falling total fuel mass flow. The strong swirl leads to a larger spray cone angle φ, which in turn compensates for the lower penetration depth of the fuel spray into the air flow. Due to the variable design of the spray cone angle φ, the atomization of the fuel can be optimally adapted to the respective operating conditions of the gas turbine. In contrast to conventional two-stage swirl nozzles, in the embodiment according to the invention both stages are in one Swirl chamber merged. In addition, depending on the load range, it is possible to atomize different liquids, for example oil 12 and water 51, in the two stages.

The pressure atomizing nozzle according to the invention can be installed, for example, in a premix burner of the double-cone type, the basic structure of which is described in EP 0 321 809 B1.

12 shows a perspective view of the double-cone burner with an integrated premixing zone. The two partial cone bodies 1, 2 are arranged radially offset from one another with respect to their longitudinal symmetry axes 1b, 2b. This creates tangential air inlet slots 19, 20 on both sides of the partial cone bodies 1, 2 in the opposite inflow arrangement, through which the combustion air 15 flows into the interior 14 of the burner, ie into the cone cavity formed by the two partial cone bodies 1, 2. The partial cone bodies 1, 2 expand in a straight line in the direction of flow, ie they have a constant angle α with the burner axis 5. The two partial cone bodies 1, 2 each have a cylindrical starting part 1a, 2a, which also run offset. In this cylindrical initial part 1a, 2a there is the pressure atomizing nozzle 3 according to the invention, which is arranged approximately in the narrowest cross section of the conical interior 14 of the burner. Of course, the burner can also be designed without a cylindrical initial part, that is to say purely conical. The liquid fuel 12 is atomized by means of the nozzle 3 in the manner described above. Different spray cone angles φ result depending on the respective operating conditions. The fuel spray 4 is enclosed in the interior 14 of the burner by the combustion air stream 15 flowing tangentially into the burner through the air inlet slots 19, 20; the mixture is ignited only at the outlet of the burner, the flame being stabilized in the region of the burner mouth by a backflow zone 6.

The two partial cone bodies 1, 2 each have a fuel feed line 8, 9 along the air inlet slots 19, 20, which are provided on the long side with openings 17 through which a further fuel 13 (gaseous or liquid) can flow. This fuel 13 is mixed with the combustion air 15 flowing through the tangential air inlet slots 19, 20 into the interior of the burner, which is represented by the arrows 16. Mixed operation of the burner via the nozzle 3 and the fuel feeds 8, 9 is possible.

On the combustion chamber side, a front plate 10 is arranged with openings 11, through which dilution air or cooling air can be supplied to the combustion chamber 22 if necessary. In addition, this air supply ensures that flame stabilization takes place at the burner outlet. There is a stable flame front 7 with a backflow zone 6.

The arrangement of guide plates 21a, 21b can be seen from FIGS. 13 to 15. These can be opened or closed, for example, about a pivot point 23, so that the original gap size of the tangential air inlet slots 19, 20 is thereby changed. Of course, the burner can also be operated without these baffles 21a, 21b.

Since there is a risk with these burners that detachment and recirculation areas form in the vicinity of the nozzle, this is prevented according to FIG. 16 by arranging a duct 24 around the nozzle 3 through which a jacket air flow 15a flows as purge air. The jacket air flow 15 a is approximately 3 to 7% of the combustion air flow 15.

Of course, a burner (see FIG. 17) can also be operated with the method just described, consisting essentially of a swirl generator 100 for a combustion air stream 15 and of means for injecting a fuel, in which a mixing section 220 is arranged downstream of the swirl generator 100 and this has transition channels 201 running in the flow direction within a first section part 200 for transferring a flow formed in the swirl generator 100 into the flow cross section 18 downstream of the transition channels 201 of the mixing section 220, the means for injecting the fuel being a pressure atomizer nozzle according to the invention, which according to one of the The method described above is operated. The swirl generator 100 is preferably a conical structure, which is acted upon tangentially several times (for example via four slots) by the combustion air flow 15 flowing in tangentially. This combustion air flow 15 wraps around the fuel drop spray 4, which was previously formed by atomizing the liquid fuel 12 in the two-stage pressure atomizing nozzle 3. The flow that is formed is seamlessly transferred to a transition piece 200, which is extended by a tube 18, using a transition geometry (transition channels 201) provided downstream of the swirl generator 100. Both parts form the mixing section 220, to which the actual combustion chamber (not shown here) is connected on the downstream side. The mixing section allows the fuel to be premixed very well with the combustion air, enables low-loss flow control and prevents the flame from re-igniting from the combustion chamber due to the maximum axial speed on the axis. Since the axial speed drops towards the wall, bores 48 are provided in the wall of the tube, through which combustion air 15 flows, which causes an increase in speed along the wall. Only downstream of the mixing tube 220 does a central backflow zone 6, which has the properties of a flame holder, form. It is also advantageous here if 3 up to 7% of the combustion air flow 15 are guided as a jacket air flow 15a around the pressure atomizing nozzle. This in turn prevents separation and recirculation areas in the vicinity of the nozzle.

Reference list

1, 2

Partial cone body

1a, 2a

cylindrical initial part

1b, 2b

Central axis of the partial cone body

3rd

Atomizer nozzle

4th

Fuel drop spray

5

Burner axis

6

Backflow zone (vortex breakdown)

7

Flame front

8, 9

Fuel supply

10th

Front panel

11

Openings in the front panel

12th

liquid fuel

13

additional fuel (liquid or gaseous)

14

Interior of the burner

15

Combustion air flow

15a

Jacket air flow (part of item 15)

16

Injection fuel

17th

openings

18th

pipe

19, 20

tangential air inlet slot

21a, 21b

Baffle

22

Combustion chamber downstream of the burner

23

pivot point

30th

Nozzle body

31

first pipe

32

Cover of item 31

33

Nozzle bore

34

Longitudinal axis of the nozzle

35

second pipe

36

Annulus between items 31 and 35

37

liquid to be atomized

37 '

second liquid to be atomized

38

tangential slit

39

Turbulence and / or swirl chamber

40

Filling piece

41

Feed channel (axially aligned)

41a

Feed channel (set tangentially)

42

pump

43

pressure vessel

44

management

45

management

46

Valve in pos. 44

47

Valve in pos. 45

48

Bores in pos. 18

49

Return valve

50

Shut-off valve

51

water

100

Swirl generator

200

Transition piece

201

Transition channel

220

Mixing tube

α

Cone half angle

φ

Spray cone angle

R

Radius of the spray

ṁ _BS

Mass flow of fuel

Claims (17)

Pressure atomizer nozzle, comprising a nozzle body (30), in which a turbulence and / or swirl chamber (39) is formed, which is connected to an outside space via a nozzle bore (33) and at least a first feed channel (41, 41a) for the Atomizing liquid (37), through which said liquid (37) can be fed under pressure, characterized in that at least one further feed channel (38) for part of the liquid to be atomized (37) or for a second one into the chamber (39) Liquid (37 ') to be atomized opens through which said part of the liquid (37) or the second liquid (37') can be supplied under pressure and with swirl. Pressure atomizer nozzle according to claim 1, characterized in that the liquid (37) to be atomized can be fed into the chamber (39) via the first feed channel (s) (41) without swirl. Pressure atomizer nozzle according to Claim 1, characterized in that the liquid (37) to be atomized can be fed into the chamber (39) via the first feed channel (s) (41a) with swirl. Pressure atomizer nozzle according to claim 2, characterized in that the nozzle bore (33) is arranged in the cover (32) of a first tube (31) in which a second tube (35) of smaller outside diameter is inserted that extends to said cover (32) and in the cover-side end of the second tube (35) there is at least one slot (38) which is positioned tangentially and forms a swirl channel and forms the annular space (36) between the first (31 ) and the second pipe (35) with the chamber (39), from which the nozzle bore (33) leads into the outside space, the chamber (39) essentially through the cover (32), the inner walls of the second pipe (35 ) and a filler (40) is limited in the second tube (35), and the first feed channel (s) (41) is / are arranged axially parallel in the filler (40). Pressure atomizer nozzle according to claim 2, characterized in that the nozzle bore (33) is arranged in the cover (32) of a first tube (31) in which a second tube (35) of smaller outside diameter is inserted, which extends to said cover (32) , and at least one slot (38) is provided in the end of the second tube (35) on the cover side, which is made tangential and forms a swirl channel and the annular space (36) between the first (31) and the second tube (35) with the chamber (39), from which the nozzle bore (33) leads into the outside space, the chamber (39) essentially through the cover (32), the inner walls of the second tube (35) and a filler (40) in the second tube ( 35) is limited, and the first feed channel (41) is arranged as an annular gap between the filler (40) and the inner walls of the second tube (35). Pressure atomizer nozzle according to claim 1, characterized in that the nozzle bore (33) is arranged in the cover (32) of a first tube (31) in which a second tube (35) of smaller outside diameter is inserted, the between the tubes (31) and (35) forming annular channel (36) is provided as a feed line for a swirl stage and the second tube (35) is delimited by a filler (40) which forms the chamber (39) with the cover (32) of the first tube (31) , In the filler (40) at least one tangentially arranged swirl channel (38) for connecting the ring channel (36) to the chamber (39) is arranged and in the second tube (35) and the filler (40) at least one feed channel (41) as Turbulence channel for the liquid to be atomized is arranged axially parallel and the supply channel (s) (41) open into the swirl channel (s) (38). Pressure atomizer nozzle according to claim 1, characterized in that the nozzle bore (33) is arranged in the cover (32) of a first tube (31) in which a second tube (35) of smaller outside diameter is inserted, the between the tubes (31) and (35) forming annular channel (36) is provided as a feed line for a swirl stage and the second tube (35) is delimited by a filler (40) which, with the cover (32) of the first tube (31), the chamber (39) forms, wherein at least one tangentially swirl channel (38) for connecting the ring channel (36) to the chamber (39) is arranged in the filler piece (40) and at least one feed channel (41) in the second tube (35) and the filler piece (40) is arranged as a turbulence channel for the liquid to be atomized and the swirl channel (s) (38) open into the supply channel (s) (41). Pressure atomizer nozzle according to claim 3, characterized in that the two swirl stages have a different spray cone angle (φ). Pressure atomizer nozzle according to Claims 3 and 8, characterized in that the nozzle bore (33) is arranged in the cover (32) of a first tube (31) in which a second tube (35) of smaller outside diameter is inserted, which extends up to the said cover (32 ) is sufficient, and at least one slot (38) is provided in the end of the second tube (35) on the cover side, which is made tangential and forms a swirl channel and also the annular space (36) between the first (31) and the second tube (35) connects the chamber (39) from which the nozzle bore (33) leads into the outside space, the chamber (39) essentially through the cover (32), the inner walls of the second tube (31) and a filler (40) in the second Pipe (35) is limited, and the first feed channel (s) (41a) is / are arranged tangentially as swirl channel / swirl channels in the filler (40). Pressure atomizer nozzle according to claim 9, characterized in that the liquid (37) to be atomized can be swirled to a lesser extent by the first supply channel (s) (41a) than the part of the liquid (37) which can be swirled by the further supply channel / channels (38). or the second liquid (37 '). Method for operating a pressure atomizing nozzle according to one of claims 1, 2, 4, 5 or 6, characterized in that the pressure atomizing nozzle is operated during full and overload operation via a swirl-free turbulence generator main stage, by the entire liquid (37) to be atomized via at least one supply channel (41) is fed to the turbulence chamber (39) without swirling, a high-turbulent flow being generated there, which then passes through the nozzle bore (33) into the outside space, and that the pressure atomizer nozzle is also used in partial and low-load operation a pressure swirl stage is operated in that a part of the liquid (37) to be atomized or the second liquid (37 ') to be atomized is swirled through the at least one further feed channel (38) and supplied to the chamber (39) and a strongly swirled flow is generated there, which then passes through the at least one nozzle bore (33) into the outside space, the proportion of the liquid (37, 37 ') supplied via the swirl stage being increased as the total liquid mass flow decreases. Method for operating a pressure atomizer nozzle according to one of claims 1, 3, 8, 9 or 10, characterized in that the pressure atomizer nozzle is operated at full and overload operation via a main pressure swirl stage with low swirl, by the entire liquid (37) to be atomized over at least a first feed channel (41a) is supplied to the swirl chamber (39) in a swirled manner, a swirled flow being generated there, which then passes through the at least one nozzle bore (33) into the outside space, and that the pressure atomizer nozzle additionally operates via a through partial and low-load operation a further pressure swirl stage with a larger swirl is operated, in that part of the liquid (37) to be atomized or the second liquid (37 ') to be atomized is supplied to the chamber (39) more swirled via the at least one further feed channel (38) and there a strong swirl swirled flow is generated, which then by the least s a nozzle bore (33) enters the outside space, the proportion of the more swirled liquid (37, 37 ') supplied via the further swirl stage being increased with a falling total liquid mass flow. A method according to claim 11 or 12, characterized in that switching smoothly between the two stages becomes. A method according to claim 11 or 12, characterized in that both stages are operated simultaneously and variably in throughput. A method according to claim 11 or 12, characterized in that only one of the two stages is operated. Method for the combustion of liquid fuel (12) in a burner without a premix section, whereby in the interior (14) of the burner, by atomizing the fuel (12) in a nozzle (3), the walls of the interior (14) do not spread in the direction of flow wetting cone-shaped liquid fuel column (fuel drop spray 4) is formed, which is enclosed by a combustion air stream (15) flowing tangentially into the burner, the ignition of the mixture taking place at the outlet of the burner and the flame in the area of the burner mouth being stabilized by a backflow zone, characterized in that that the nozzle (3) is a pressure atomizing nozzle according to one of claims 1 to 10, which is operated with a method according to one of claims 11 to 15, and that 3 to 7% of the combustion air flow (15) as a jacket air flow (15a) around the Nozzle (3) are guided. Method for the combustion of liquid fuel (12) in a burner with a premixing section, whereby in the interior (14) of the burner, by atomizing the fuel (12) in a nozzle (3), the walls of the interior (14) do not spread in the direction of flow wetting cone-shaped liquid fuel column (fuel drop spray 4) is formed, which is surrounded by a combustion air flow (15) flowing tangentially into the burner and thereby swirled Flow is generated, which reaches a mixing section (220) downstream via transition channels (201) running in the direction of flow, and the ignition of the mixture only takes place at the outlet of the burner, the flame in the area of the burner mouth being stabilized by a backflow zone, characterized in that that the nozzle (3) is a pressure atomizing nozzle according to one of claims 1 to 10, which is operated with a method according to one of claims 11 to 15, and that 3 to 7% of the combustion air flow (15) as a jacket air flow (15a) around the nozzle (3) be performed.

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