DE102022002113A1 - Burner for a motor vehicle, method for operating such a burner and motor vehicle - Google Patents

Abstract

The invention relates to a burner (12) for an exhaust tract (10) through which exhaust gas from an internal combustion engine of a motor vehicle flows, with a combustion chamber (16) in which a mixture comprising air and a fuel (84) is to be ignited and thereby burned an inner swirl chamber (20) through which a first part of the air can flow, which has a first swirl generating device (55), by means of which a swirl-shaped flow (50) of the first part of the air can be brought about, and one which flows through the inner swirl chamber (20). has a first outflow opening (22) through which the first part of the air can flow, via which the first part of the air can be removed from the inner swirl chamber (20), and with an introduction element (24) through which the fuel can flow, by means of which the fuel (84) is in the inner swirl chamber (20) can be introduced, the first outflow opening (22) of which can also be flowed through by the fuel (84) discharged from the introduction element (24).

Description

The invention relates to a burner for an exhaust tract through which exhaust gas from an internal combustion engine of a motor vehicle can flow. The invention further relates to a method for operating such a burner. The invention also relates to a motor vehicle, in particular a motor vehicle, with at least one such burner.

Motor vehicles with internal combustion engines and exhaust systems, which are also referred to as exhaust tracts, are known from the general state of the art and in particular from series vehicle construction. Exhaust gas from the respective internal combustion engine, also known as an internal combustion engine, can flow through the respective exhaust gas tract. In some operating states or operating situations of the respective internal combustion engine, a high temperature of the exhaust gas may be desirable in order, for example, to be able to quickly heat up and/or keep warm an exhaust gas aftertreatment device arranged in the exhaust tract, although in these operating states or operating situations the actual temperature of the exhaust gas is only insufficiently high.

The DE 37 29 861 C2 a method for operating a soot filter device for a diesel engine can be seen as known. Furthermore, the reveals DE 11 2012 001 594 T5 an object having an engine or engine component and a coating applied to the engine or engine component. Furthermore, from the DE 11 2012 001 599 T5 a method for applying a coating to an engine, an exhaust system or an engine component is known.

Furthermore, from the DE 196 27 760 C2 a burner for combustion chambers of gas turbines is known, with an atomizer nozzle for atomizing fuel into combustion air. In addition, the reveals DE 198 03 879 C1 a burner for the oxidation of liquid fuel with air.

The object of the present invention is to create a burner for an exhaust tract of a motor vehicle, a method for operating such a burner and a motor vehicle with at least one such burner, so that a particularly advantageous operation of the burner can be realized.

This object is achieved by a burner with the features of patent claim 1, by a method with the features of patent claim 9 and by a motor vehicle with the features of patent claim 10. Advantageous embodiments with useful developments of the invention are specified in the remaining claims.

A first aspect of the invention relates to a burner for an exhaust gas tract through which exhaust gas from an internal combustion engine of a motor vehicle, also referred to as an internal combustion engine or internal combustion engine, can flow. This means that the motor vehicle, which can preferably be designed as a motor vehicle and most preferably as a passenger car, has the internal combustion engine and the exhaust tract in its fully manufactured state and can be driven by the internal combustion engine. During fired operation of the internal combustion engine, combustion processes take place in the internal combustion engine, in particular in at least one or more combustion chambers of the internal combustion engine, resulting in the exhaust gas from the internal combustion engine. The exhaust gas can flow out of the respective combustion chamber and flow into the exhaust tract and subsequently flow through the exhaust tract, which is also referred to as the exhaust system. At least one component, such as an exhaust gas aftertreatment element for aftertreating the exhaust gas, can be arranged in the exhaust gas tract. The exhaust gas aftertreatment element is, for example, a catalyst, in particular an SCR catalyst, wherein, for example, a selective catalytic reduction (SCR) can be catalytically supported and/or brought about by means of the SCR catalyst, so that, for example, the SCR catalyst is catalytic for the SCR is active. During the selective catalytic reduction, any nitrogen oxides contained in the exhaust gas are at least partially removed from the exhaust gas by the nitrogen oxides reacting with ammonia to form nitrogen and water during the selective catalytic reduction. The ammonia is provided, for example, by a particularly liquid reducing agent. Furthermore, the exhaust gas aftertreatment element can be a particle filter, in particular a diesel particle filter, or can comprise a particle filter, in particular a diesel particle filter, wherein particles contained in the exhaust gas, in particular soot particles, can be filtered out of the exhaust gas by means of the particle filter.

The burner has a combustion chamber, also known as the main combustion chamber, in which a mixture comprising air and a preferably liquid fuel can be ignited and thereby burned. As a result of the combustion of the mixture taking place in particular in the combustion chamber, a burner exhaust gas from the burner is generated, in particular in the combustion chamber. The burner exhaust gas can, for example, flow out of the combustion chamber and into the exhaust gas tract, that is, for example, into one of the exhaust gases from the combustion chamber The exhaust gas duct of the exhaust tract through which flow can flow through the engine, in particular at an introduction point which, for example, is arranged upstream of the aforementioned component in the flow direction of the exhaust gas of the internal combustion engine flowing through the exhaust tract or the exhaust duct. For example, the burner exhaust gas mixes with the exhaust gas from the internal combustion engine. This is particularly advantageous in the case of a cold start or an internal combustion engine that has not yet completely reached an operating temperature, since as a result the burner exhaust gas, in particular the burner exhaust gas mixed with the exhaust gas of the internal combustion engine, can flow through the component, for example, whereby the component can be heated up, that is, heated . In particular, it is conceivable that the burner exhaust gas can flow out of the burner chamber and flow into the exhaust tract or into the aforementioned exhaust duct and thereby be mixed with the exhaust gas of the internal combustion engine flowing through the exhaust tract, also referred to as engine exhaust gas, and/or with a gas flowing through the exhaust tract , whereby the exhaust gas of the internal combustion engine or the gas is heated. In other words, a particularly high temperature of the exhaust gas of the internal combustion engine or of the gas, also referred to as exhaust gas temperature, can be achieved in this way. In particular, the gas can be, for example, air or combustion air, which flows through, for example, the exhaust tract or the exhaust duct, in particular while the internal combustion engine is not being operated, so that the internal combustion engine does not provide any exhaust gas, in which case, for example, the gas, in particular the combustion air, from the internal combustion engine is conveyed through the exhaust tract. Due to the high exhaust gas temperature, the component can be heated because the exhaust gas with the burner exhaust or the gas with the burner exhaust flows through the component. Thus, for example, the burner exhaust gas is introduced from the combustion chamber at the aforementioned introduction point into the exhaust tract or into the exhaust duct and thus into the exhaust gas or gas flowing through the exhaust tract. For example, an ignition device, in particular an electrically operable one, is provided, wherein the burner can include the ignition device. In particular, it is conceivable that the ignition device is at least partially arranged in the combustion chamber. By means of the ignition device, at least one ignition spark for igniting the mixture can be provided, that is, generated, in particular in the combustion chamber and/or using electrical energy, so that the mixture can be ignited in the combustion chamber, in particular by means of the ignition spark. The ignition device is, for example, a glow plug or a spark plug.

The burner has an inner swirl chamber through which a first part of the air forming the mixture in the combustion chamber can flow and which causes a swirl-shaped flow of the first part of the air, which is therefore preferably upstream of the combustion chamber in the flow direction of the first part of the air flowing through the inner swirl chamber is arranged. When we talk about air below, unless otherwise stated, this refers to the air forming the mixture in the combustion chamber, that is to say the air from which the mixture is formed, in particular together with the fuel. The air is, for example, ambient air. The inner swirl chamber has, in particular, a first outflow opening through which the first part of the air flowing through the inner swirl chamber can flow, via which the first part of the air flowing through the first outflow opening can be removed from the inner swirl chamber and, for example, introduced into the combustion chamber. Thus, in particular, the combustion chamber is arranged downstream of the inner swirl chamber in the flow direction of the first part of the air flowing through the inner swirl chamber. The feature that the inner swirl chamber causes or can cause a swirl-shaped flow of the first part of the air flowing through the inner swirl chamber is to be understood in particular as meaning that the first part of the air flows through the inner swirl chamber in a swirl-shaped manner, i.e. at least a first portion of the inner swirl chamber flows through in a swirl-shaped manner, and/or the first part of the air only has its swirl-shaped flow at least in a first flow region arranged downstream of the inner swirl chamber and outside the inner swirl chamber, which is arranged, for example, in the combustion chamber. In particular, it is conceivable that the first part of the air flows out of the inner swirl chamber in a swirl shape via the first outflow opening and/or flows in a swirl shape into the combustion chamber, so that it is very preferably provided that the first part of the air flows in a swirl shape at least in the combustion chamber having. In particular, it is conceivable that the first part of the air already has its swirl-shaped flow in the inner swirl chamber, at least in the aforementioned, at least a first portion of the inner swirl chamber.

The burner also has an introduction element, in particular an injection element, which has at least or exactly one outlet opening through which the preferably liquid fuel can flow. In particular, it is conceivable that the insertion element has several, in particular more than two, outlet openings, which che can flow through the preferably liquid fuel. In particular, it is conceivable that the introduction element has at least or exactly three outlet openings through which the fuel can flow. By means of the introduction element, the fuel can be introduced, in particular directly, into the inner swirl chamber, in particular injected, so that the first outflow opening is also supplied by the preferably liquid, in particular ejected, via the at least one outlet opening from the introduction element, and thereby, in particular directly, into the fuel introduced, in particular injected, into the inner swirl chamber can flow through. This means in particular that the first part of the air and the fuel can flow through the first outflow opening along a common, first flow direction and thereby flow out of the inner swirl chamber.

Furthermore, the burner comprises an outer swirl chamber, which surrounds at least a length region of the inner swirl chamber and preferably also the first outflow opening in the circumferential direction of the inner swirl chamber, in particular completely circumferentially. The circumferential direction of the inner swirl chamber runs, for example, in the aforementioned first flow direction, which runs, for example, in the axial direction of the inner swirl chamber and thus of the first outflow opening, and therefore coincides with the axial direction of the inner swirl chamber and thus of the outflow opening. It is preferably provided that the inner swirl chamber is in the flow direction of the first part flowing through the first outflow opening and thus in the flow direction of the fuel flowing through the first outflow opening, therefore in the axial direction of the inner swirl chamber and thus the first outflow opening at the first outflow opening or at its end ends. The outer swirl chamber, whose axial direction coincides with the axial direction of the inner swirl chamber, can be flowed through by a second part of the air and is designed to cause a swirl-shaped flow of the second part of the air. This is to be understood in particular as meaning that the second part of the air flows in a swirling manner in the outer swirl chamber, and therefore flows in a swirling manner through at least a second portion of the outer swirl chamber, and/or the second part of the air points in a second part flowing through the outer swirl chamber in the flow direction of the outer swirl chamber Part of the air has its swirl-shaped flow in the second flow region arranged downstream of the outer swirl chamber, which, for example, coincides with the aforementioned first flow region, wherein the second flow region can be arranged, for example, outside the outer swirl chamber and, for example, inside the combustion chamber. Furthermore, it is conceivable that the aforementioned first flow region is arranged outside the outer swirl chamber. Expressed again in other words, it is conceivable that the second part of the air flows out of the outer swirl chamber in a swirl shape and/or flows into the combustion chamber in a swirl shape, so that it is preferably provided that the second part of the air has its swirl shape at least in the combustion chamber .

The outer swirl chamber has, in particular precisely, a second part of the air flowing through the outer swirl chamber, of the fuel flowing through the first outflow opening and of the first part of the air flowing through the inner swirl chamber and the first outflow opening and, for example, in the flow direction of the parts of the air and the fuel, arranged downstream of the first outflow opening, through which the second part of the air can be removed from the outer swirl chamber and the parts of the air and the fuel can be introduced into the combustion chamber.

Thus, for example, the feature that the outer swirl chamber causes or can cause a swirl-shaped flow of the second part of the air flowing through the outer swirl chamber is to be understood in particular as meaning that the second part of the air flows through the outer swirl chamber in a swirl-shaped manner, i.e. at least a second partial area flows through the outer swirl chamber in a swirl shape, and / or the second part of the air only has its swirl-shaped flow at least in a second flow region arranged downstream of the outer swirl chamber and outside the outer swirl chamber, which is arranged, for example, in the combustion chamber. In particular, it is conceivable that the second part of the air flows out of the outer swirl chamber in a swirl shape via the second outflow opening and/or flows in a swirl shape into the combustion chamber, so that it is very preferably provided that the second part of the air flows in a swirl shape at least in the combustion chamber having. In particular, it is conceivable that the second part of the air already has its swirl-shaped flow in the outer three-chamber, at least in the aforementioned, at least a second partial area of the outer swirl chamber,

In particular, it can thus be provided that the combustion chamber is arranged downstream of the inner swirl chamber and/or downstream of the outer swirl chamber in the flow direction of the respective part of the air flowing through the respective swirl chamber. In particular, the parts of the air and the fuel can flow along a second flow direction through the second outflow opening and thus via the second outflow opening flow into the combustion chamber, for example the second flow direction running parallel to the first flow direction or coinciding with the first flow direction. Furthermore, it is preferably provided that the second flow direction runs in the axial direction of the outer swirl chamber, and therefore coincides with the axial direction of the outer swirl chamber, so that it is very preferably provided that the axial direction of the inner swirl chamber corresponds to the axial direction of the outer swirl chamber vice versa. Expressed again in other words, it is preferably provided that the axial direction of the inner swirl chamber coincides with the axial direction of the outer swirl chamber or vice versa. The respective axial direction of the respective swirl chamber runs perpendicular to the respective radial direction of the respective swirl chamber, the radial direction of the inner swirl chamber preferably coinciding with the radial direction of the outer swirl chamber or vice versa. For example, since the second outflow opening is arranged downstream of the first outflow opening along the respective flow direction, that is in the flow direction of the respective part of the air and in the flow direction of the fuel, and since the outer swirl chamber preferably surrounds the first outflow opening, the first outflow opening is, for example, in the outer swirl chamber arranged. In particular, it is conceivable that the outer swirl chamber, in particular in the flow direction of the second part of the air flowing through the second outflow opening, ends at the second outflow opening, in particular at its end.

In order to generate the respective swirl-shaped flow, the respective swirl chamber can have at least one or more swirl generators, by means of which the respective swirl-shaped flow can be generated or is generated. In particular, the respective swirl generator is arranged in the respective swirl chamber. In particular, the respective swirl generator can be, for example, a guide vane, by means of which, for example, the respective part, that is to say the respective air forming the respective part, is deflected at least or exactly once, in particular by at least or exactly 70 °, in particular by at least 1 Essentially 90°, that is, for example, around 70° to 90°. In particular, the respective swirl-shaped flow is to be understood as meaning a flow which extends in a swirl-shaped manner, that is to say at least essentially in a helical or helical shape, around the respective axial direction of the respective swirl chamber or the respective outflow opening. In particular, the respective axial direction of the respective outflow opening runs perpendicular to a plane in which the respective outflow opening runs. For example, the respective axial direction of the respective outflow opening coincides with the respective axial direction of the respective swirl chamber. The respective outflow opening is also referred to, for example, as the respective nozzle, whose cross section through which the respective part of the air can flow does not necessarily have to taper along the respective flow direction, but can taper. Thus, for example, the second outflow opening is also referred to as an outer nozzle or second nozzle, with the first outflow opening, for example, also being referred to as an inner nozzle or first nozzle.

By effecting the respective, swirl-shaped flow, the air can be particularly advantageously mixed with the preferably liquid fuel, in particular over a small mixing path, in particular in the combustion chamber, so that a particularly advantageous mixture preparation is realized, that is to say the mixture can be formed particularly advantageously. In particular, the fuel can initially be mixed particularly well with the first part of the air, in particular in the inner swirl chamber, in particular due to the swirl-shaped flow of the first part of the air, in particular in the inner swirl chamber. In addition, the fuel and, for example, the first part of the air already mixed with the fuel can be particularly advantageously mixed with the second part of the air, in particular in the outer swirl chamber and/or in the combustion chamber, since the second part of the air also has an advantageous, has a swirl-shaped flow. Overall, due to the swirl-shaped flows, the parts of the air and the fuel can be mixed particularly advantageously, so that an advantageous mixture preparation can be achieved. The swirl-shaped flow of the first part of the air and the swirl-shaped flow of the second part of the air have the same direction of the respective swirl, in particular the two flows coincide.

The inner swirl chamber has a first, inner swirl generating device, by means of which the first, swirl-shaped flow of the first part of the air can be brought about.

Thus, for example, the inner swirl generating device has the aforementioned, at least one swirl generator of the inner swirl chamber. Furthermore, the outer swirl chamber has an external, second swirl generating device, by means of which the second, swirl-shaped flow of the second part of the air can be brought about. Thus, for example, the outer swirl generating device has the aforementioned, at least one swirl generator in the outer swirl chamber. For example, the two form twisters supply devices a swirl generating device or the swirl generating devices are components of a swirl generating device of the burner. In particular, it is conceivable that the two swirl generating devices are formed in one piece with one another, that is to say are formed by a one-piece component, so that the two swirl generating devices are formed, for example, from a single piece, that is to say by a single piece. This is to be understood as meaning that the swirl generating devices are not designed as components that are designed separately from one another and are connected to one another. Furthermore, it is conceivable that the swirl generating devices are designed separately from one another and, in particular, are components that are connected to one another. For example, the first swirl generating device has at least one or more first swirl generating elements, such as preferably first guide vanes, wherein by means of the first swirl generating element or by means of the first swirl generating elements, the air or the first part of the air can advantageously be guided or deflected or redirected in such a way that the swirl-shaped flow of the first part of the air can be effected, that is, is effected. Thus, for example, the first swirl generating element is the aforementioned swirl generator of the inner swirl chamber. Alternatively or additionally, it is conceivable that the second swirl generating device comprises at least one or more second swirl generating elements, such as preferably second guide vanes, wherein the air or the second part of the air can be guided or deflected or deflected in this way by means of the second swirl generating element or by means of the second swirl generating elements that the second swirl-shaped flow of the second part of the air can be brought about, that is, is effected. In particular, it is conceivable that the second swirl generating element is the aforementioned swirl generator of the outer swirl chamber. Preferably, it is provided that the swirl generating elements of the respective swirl generating device are arranged successively and/or spaced apart from one another in the circumferential direction of the respective swirl chamber, in particular around the respective axial direction of the respective swirl chamber. For example, the at least one first portion of the inner swirl chamber is arranged downstream of the first swirl generating device in the flow direction of the first part of the air flowing through the inner swirl chamber. Furthermore, it is conceivable that the at least one second portion of the outer swirl chamber is arranged downstream of the second swirl generating device in the flow direction of the second part of the air flowing through the outer swirl chamber.

In particular, it is conceivable that the respective swirl generating elements of the respective swirl chamber form, that is, in particular directly, delimit respective swirl channels through which the respective part of the air can flow, so that the respective swirl-shaped flow can be brought about or is brought about by means of the swirl channels. In particular, it is possible for the swirl channels to be arranged successively and in particular at a distance from one another in the circumferential direction of the respective swirl chamber.

In order to be able to realize a particularly advantageous operation of the burner, it is provided according to the invention that the introduction element is designed to introduce the fuel into the inner swirl chamber in a clocked manner, in particular to inject it. In other words, the burner is designed to operate the introduction element in a clocked manner, that is to say in a clocked operation, whereby the fuel can be introduced, in particular injected, into the inner swirl chamber in a clocked manner by means of the introduction element or is introduced, in particular injected. The clocked operation of the introducing element and thus the feature that the introducing element is designed to introduce the fuel into the inner swirl chamber in a clocked manner, i.e. that the introducing element introduces the fuel into the inner swirl chamber in a clocked manner, is to be understood as meaning that the introducing element is within a in particular a predetermined or predeterminable period of time, a larger number of introduction processes, in particular injection processes, than one, in particular four and in particular ten, whereby during the respective introduction process the introduction element supplies the fuel, that is to say a respective, in particular predetermined or predeterminable amount of fuel, into the inner swirl chamber, in particular injects it, that is in particular ejects it from itself and injects it into the inner swirl chamber, and the introduction processes carried out within the time period are spaced apart in time, so that between two directly successive introduction processes there is an introduction of fuel caused by the introduction into the inner swirl chamber. In particular, the number of introduction processes is at least ten, in particular greater than ten and very preferably greater than 20, in particular greater than 50. Since the introduction processes carried out within the time period, in particular in pairs, are spaced apart in time, the introduction processes, in particular in pairs, are by one respective, in particular by the same, spaced apart in time. Expressed again in other words, there is a respective time interval, in particular, between two immediately consecutive insertion processes the same time interval, it being preferably provided that the time interval is less than two seconds, in particular less than one second and most particularly less than half a second. Thus, the insertion processes carried out within the time period have a frequency or the insertion element, in its clocked operation, carries out the insertion processes within the time period with a particular predetermined or predefinable frequency, the frequency in particular in the unit Hertz, as is generally known, the number of the insertion processes carried out within the time period per second, and therefore expresses the insertion processes carried out within the time period or the number of insertion processes carried out within the time period in relation to one second, that is to say relates or normalises to one second. It is conceivable that the period of time is exactly one second or is shorter or longer than one second. The invention is based in particular on the following findings and considerations: It was found that a non-clocked, continuous introduction, in particular injection, of the fuel into the inner swirl chamber leads to a wave-shaped spread of the fuel introduced into the inner swirl chamber by means of the introduction element in the inner Swirl chamber, in particular on a component that forms or delimits the inner swirl chamber, in particular directly, and is also referred to as a prefilmer or film layer. In other words, the inner swirl chamber is delimited, for example, in particular directly, by the component mentioned, in particular by a surface of the component which is designed, for example, as an inner circumferential and in particular concavely curved lateral surface, the component also being referred to as a prefilmer or film layer. A non-clocked, continuous introduction, in particular injection, of the fuel into the inner swirl chamber now leads to a wave-shaped spread of the fuel on the component, that is, for example, on the surface. This is to be understood in particular as meaning that the fuel or its flow introduced into the inner swirl chamber and thus applied, in particular sprayed, onto the surface mentioned has at least one or more waves. This can cause droplets of fuel to break off on the shaft, which can lead to undesirably poor combustion of the mixture in the combustion chamber. The clocked introduction, in particular injection, of the fuel can prevent an undesirable build-up of waves, that is, an undesirable, wave-shaped flow of the fuel on the surface, so that the fuel is at least substantially uniform in the inner swirl chamber and in particular on the component , in particular on the surface, distributed and subsequently, for example, at one end of the component and in particular at a, in particular sharp-edged, end edge provided at the end of the component, which is also referred to as a sharp lip or sharp tear-off lip or as a sharp lip or sharp tear-off lip is trained, breaks down. The sharp-edged end edge forms the first outflow opening of the inner swirl chamber. As a result, the fuel can be distributed in advantageously fine droplets in the combustion chamber, so that a particularly advantageous combustion of the mixture and thus an advantageous and particularly efficient operation of the burner can be guaranteed.

For example, an electronic computing device, also known as a control device, is provided, by means of which the insertion element can be controlled or is controlled, in particular in that the control device provides at least one electrical signal which is received by the insertion element. In particular, the introduction element is electrically operable, so that the pressurized fuel can be introduced into the inner swirl chamber using electrical energy by means of the introduction element. By means of the electronic computing device, the insertion element is operated in a clocked manner, in particular by controlling the insertion element. For example, the insertion element has a valve element which is movable in particular relative to a housing of the insertion element between a closed position and at least one open position. For example, the at least one outlet opening of the insertion element is delimited, in particular directly, by said housing of the insertion element. In the closed position, the at least one outlet opening is fluidically blocked by the valve element, so that the introduction element does not provide any fuel, and therefore the fuel is not introduced into the inner swirl chamber by the introduction element. In the open position, the valve element releases the at least one outlet opening, so that the introduction element provides, in particular ejects, the fuel and introduces, in particular injects, the fuel into the inner swirl chamber. In particular, by controlling the insertion element, the valve element is moved, for example, from the open position into the closed position. In particular, it is conceivable that by activating the insertion element, the valve element is moved from the closed position into the open position and is held in the open position, in particular continuously and thus without interruption, during a so-called control period. The control period therefore corresponds at least essentially to an introduction period, also referred to as an injection period, during which the introduction element carries out the combustion material, in particular continuously and therefore without interruption, provides, in particular ejects, and introduces, in particular injects, into the inner swirl chamber. The control period or introduction period is therefore at least essentially a period of time during which the respective introduction process is carried out, in particular continuously and therefore without interruption. In the case of the clocked operation of the introduction element, it is in particular provided that the introduction of the fuel, also known as metering, into the inner swirl chamber takes place with a high frequency of introduction processes and with a short control duration, so that the number of introduction processes within the period of time is very high, however the respective control duration, therefore the respective time duration of the respective insertion process, viewed alone, is relatively short. As a result, undesirable, excessive wave formation can be avoided, particularly on the aforementioned surface of the component, so that particularly efficient operation of the burner can be guaranteed. In particular, the invention can realize that an at least essentially uniform film, also referred to as a fuel film, is formed on the component, in particular on the said surface of the component, by the fuel introduced into the inner swirl chamber on the prefilmer by means of the introduction element , which leads to advantageously small droplets of fuel with an advantageously large overall surface area and thus to stable and efficient and environmentally friendly combustion behavior at an outlet of the component or the inner swirl chamber, i.e. at the first outflow opening and especially at the end edge.

In a particularly advantageous embodiment of the invention, it is provided that the frequency is at least 50 Hertz. In other words, it is preferably provided that the introduction element is designed to introduce the fuel into the inner swirl chamber in a clocked manner at a frequency of at least 50 Hertz, so that the injection processes are preferably carried out within the time period at a frequency of 50 Hertz. In other words, it is preferably provided that 50 injection processes per second are carried out within the time period. This means that excessive wave formation of the fuel introduced into the inner swirl chamber can be avoided, so that a particularly efficient and low-pollutant combustion behavior can be achieved.

A further embodiment is characterized in that the frequency is at least 80 Hertz. In other words, it is preferably provided that the introduction element is designed to introduce the fuel into the inner swirl chamber in a clocked manner at a frequency of at least 80 Hertz. In this way, a particularly advantageous fuel film can be produced on the surface, which is atomized into particularly advantageously small droplets with a particularly advantageously large overall surface, in particular at the end edge and most particularly by an atomizer lip, in particular of the component, which is designed in particular as a solid body and forms the end edge.

It has proven to be particularly advantageous if the frequency is at least or exactly 100 Hertz. In other words, it has proven to be particularly advantageous if the introduction element is designed to introduce the fuel into the inner swirl chamber at a frequency of at least or exactly 100 Hertz. It was found that a frequency of 100 Hertz leads to a particularly advantageously uniform fuel film on the surface and, as a result, to particularly advantageously small fuel droplets, so that particularly efficient and low-emission combustion can be guaranteed.

In a further, particularly advantageous embodiment of the invention, the introduction element has at least one outlet opening through which the fuel flowing through the introduction element can flow, via which the fuel flowing through the outlet opening can be removed from the introduction element and thereby introduced, in particular injected, into the inner swirl chamber. In particular, it has been shown that three evenly arranged outlet openings in particular produce a particularly uniform fuel film. It is also conceivable to provide more than three outlet openings.

It has proven to be particularly advantageous if the outlet opening of the introduction element can be flowed through in an introduction direction by the fuel flowing through the outlet opening, the introduction direction running obliquely to the axial direction of the swirl chamber. Because the introduction direction runs obliquely to the axial direction of the inner swirl chamber, a particularly advantageous, at least essentially uniform, fuel film can be generated on the surface, which can be particularly advantageously atomized into small droplets.

In order to be able to realize a particularly advantageous mixture preparation and thus a particularly advantageous operation of the burner, it is provided in a further embodiment of the invention that the first part of the air can be fed to the inner swirl chamber in the radial direction of the inner swirl chamber from the outside to the inside. In other words The first part of the air flows into the first swirl chamber not axially, but radially.

Alternatively or additionally, it is provided that the second part of the air can be supplied to the outer swirl chamber in the radial direction of the outer swirl chamber from the outside to the inside. In other words, the second part of the air flows into the outer swirl chamber not in the axial direction of the outer swirl chamber but in the radial direction of the outer swirl chamber, whereby a particularly advantageous mixture preparation can be achieved.

A second aspect of the invention relates to a method for operating a burner according to the first aspect of the invention. In the method, the fuel is introduced, in particular injected, into the inner swirl chamber in a clocked manner using the introduction element. Advantages and advantageous refinements of the first aspect of the invention are to be viewed as advantages and advantageous refinements of the second aspect of the invention and vice versa.

A third aspect of the invention relates to a motor vehicle, preferably designed as a motor vehicle, in particular as a passenger car, which has an internal combustion engine by means of which the motor vehicle can be driven. The motor vehicle also has an exhaust gas tract through which exhaust gas from the internal combustion engine can flow, which has at least one burner according to the first aspect of the invention. Advantages and advantageous refinements of the first aspect of the invention are to be viewed as advantages and advantageous refinements of the second aspect of the invention and vice versa. Advantages and advantageous embodiments of the first and second aspects of the invention are to be viewed as advantages and advantageous embodiments of the third aspect of the invention and vice versa.

Further advantages, features and details of the invention result from the following description of a preferred exemplary embodiment and from the drawing. The features and combinations of features mentioned above in the description as well as the features and combinations of features mentioned below in the description of the figures and/or shown in the figures alone can be used not only in the combination specified in each case, but also in other combinations or on their own, without the scope of to abandon invention.

• 1 ausschnittsweise eine schematische Schnittansicht eines Abgastrakts einer Verbrennungskraftmaschine eines Kraftfahrzeugs, mit einem Brenner;
• 2 ausschnittsweise eine weitere schematische Schnittansicht des Abgastrakts;
• 3 ausschnittsweise eine weitere schematische Schnittansicht des Abgastrakts;
• 4 eine schematische Längsschnittansicht des Brenners;
• 5 eine schematische Perspektivansicht einer Drallerzeugungsvorrichtung des Brenners;
• 6 eine schematische und perspektivische Längsschnittansicht der Drallerzeugungsvorrichtung;
• 7 ein Diagramm zum Veranschaulichen eines Verfahrens zum Betreiben des Brenners;
• 8 ausschnittsweise eine schematische Längsschnittansicht eines Einbringelements des Brenners; und
• 9 ausschnittsweise eine schematische Schnittansicht eines Bauteils des Brenners.

The drawing shows in:

• 1 a detail of a schematic sectional view of an exhaust tract of an internal combustion engine of a motor vehicle, with a burner;
• 2 a detail of a further schematic sectional view of the exhaust tract;
• 3 a detail of a further schematic sectional view of the exhaust tract;
• 4 a schematic longitudinal sectional view of the burner;
• 5 a schematic perspective view of a swirl generating device of the burner;
• 6 a schematic and perspective longitudinal section view of the swirl generating device;
• 7 a diagram illustrating a method of operating the burner;
• 8th a detail of a schematic longitudinal sectional view of an insertion element of the burner; and
• 9 a detail of a schematic sectional view of a component of the burner.

In the figures, identical or functionally identical elements are provided with the same reference numerals.

1 shows a detail in a schematic sectional view of an exhaust tract 10, also known as an exhaust system, of a motor vehicle preferably designed as a motor vehicle, in particular as a passenger car. The motor vehicle has a drive device, not shown in the figures, by means of which the motor vehicle can be driven. The motor vehicle also has the exhaust tract 10. The motor vehicle is a land vehicle. The drive device has an internal combustion engine, also referred to as an internal combustion engine or internal combustion engine, which has an engine block, also referred to as a motor housing. Furthermore, the internal combustion engine has at least one or more cylinders, which are formed or limited by the engine block, in particular directly. During fired operation of the internal combustion engine, respective combustion processes take place in the cylinders, resulting in exhaust gas from the internal combustion engine. For this purpose, a particularly liquid fuel is introduced into the respective cylinder within a respective working cycle of the internal combustion engine, in particular injected directly. The internal combustion engine can be designed as a diesel engine, so that the fuel is preferably a diesel fuel. A tank, referred to as a fuel tank, is also provided in which the fuel can be accommodated or accommodated. For example, a respective injector is assigned to the respective cylinder, by means of which the fuel can be introduced into the respective cylinder, in particular can be injected directly. For example, by means of a low-pressure pump, the fuel is conveyed from the tank to a high-pressure pump, by means of which the fuel is conveyed to the injectors or to a fuel distribution element common to the injectors and also referred to as a rail or common rail. The injectors can be supplied with fuel from the fuel distribution element common to the injectors by means of the fuel distribution element and can introduce the fuel from the fuel distribution element into the respective cylinder, in particular inject it directly.

The drive device comprises, for example, an intake tract through which fresh air can flow, by means of which the fresh air flowing through the exhaust tract is guided to and into the cylinders. The fresh air forms a fuel-air mixture with the fuel, which includes the fresh air and the fuel and is ignited in the respective cylinder within the respective working cycle and thereby burned. In particular, the fuel-air mixture is ignited by self-ignition. Igniting and burning the fuel-air mixture results in the exhaust gas of the internal combustion engine, the exhaust gas of which is also referred to as machine exhaust gas or engine exhaust gas.

The drive device has, for example, the exhaust gas tract 10 through which the exhaust gas from the cylinder of the internal combustion engine can flow. The internal combustion engine also includes, for example, an exhaust gas turbocharger, which has a compressor arranged in the intake tract and a turbine arranged in the exhaust tract. The exhaust gas can first flow out of the cylinders into the turbine, flow out of the turbine into the exhaust tract 10 and then flow through the exhaust tract 10. The turbine can be driven by the exhaust gas flowing through the exhaust tract 10. The compressor can be driven by the turbine, in particular via a shaft of the exhaust gas turbocharger. By driving the compressor, the fresh air or ambient air flowing through the intake tract is compressed by means of the compressor. For example, several components are arranged in the exhaust tract 10, which are designed as respective exhaust gas aftertreatment devices or exhaust gas aftertreatment elements, that is, as exhaust gas aftertreatment components for aftertreating the exhaust gas. In the direction of flow of the exhaust gas from the internal combustion engine flowing through the exhaust tract 10, the components are arranged one after the other and are therefore connected in series or in series with one another. A first of the components 11 is, for example, an oxidation catalyst, in particular a diesel oxidation catalyst (DOC). Furthermore, the first component 11 can be a nitrogen oxide storage catalyst (NSK) or the first component 11 can have such a nitrogen oxide storage catalyst. A second of the components can be an SCR catalytic converter, which is also simply referred to as SCR. A third of the components can be a particle filter, in particular a diesel particle filter (DPF), whereby the diesel particle filter (DPF) can also act as the first component 11. A fourth of the components can be, for example, a second SCR catalyst and/or an ammonia barrier catalyst (ASC). In other words, for example, the fourth component can have a second SCR catalyst and/or an ammonia barrier catalyst.

The motor vehicle has a structure designed, for example, as a self-supporting body, which forms or delimits an interior of the motor vehicle, also referred to as a passenger cell or safety cell or passenger compartment. People can be in the interior while the motor vehicle is traveling. For example, the structure forms or delimits an engine compartment in which the internal combustion engine is arranged. For example, the exhaust gas turbocharger is also arranged in the engine compartment. The structure also has a floor, also referred to as a main floor, through which the interior is at least partially, in particular at least predominantly or completely, limited downwards in the vertical direction of the vehicle. For example, the first component 11, the second component and the third component are arranged in the engine compartment, so that, for example, the first component, the second component and the third component form a so-called hot end or are part of a so-called hot end (hot end). In particular, the hot end can be flanged directly to the turbine. The fourth component is, for example, arranged outside the engine compartment and below the floor in the vertical direction of the vehicle, so that, for example, the fourth component forms a so-called cold end or is part of a so-called cold end.

The exhaust tract 10 can include at least one metering device, by means of which a particularly liquid reducing agent can be introduced into the exhaust tract 10 and, for example, into the exhaust gas flowing through the exhaust tract 10 at an introduction point. The reducing agent is preferably an aqueous urea solution, which can provide ammonia, which is used in a selective catalytic reduction with any nitrogen oxide contained in the exhaust gas which can react to form water and nitrogen. The selective catalytic reduction can be catalytically effected and/or supported by the SCR catalyst. In the flow direction of the exhaust gas flowing through the exhaust tract 10, the introduction point is arranged, for example, upstream of the second component and downstream of the first component 11, with the second component being arranged downstream of the first component 11. It is also conceivable that the insertion point is arranged upstream of the first component 11. For example, the fourth component is arranged downstream of the third component, with the third component being arranged downstream of the second component. For example, the exhaust tract has a mixing chamber in which the reducing agent introduced into the exhaust gas at the point of introduction can advantageously be mixed with the exhaust gas, for example the mixing chamber can be arranged upstream of the second component and, for example, downstream of the first component.

The exhaust tract 10 and thus the drive device and the motor vehicle also include a burner 12, by means of which, as will be explained in more detail below, at least one of the components, for example the first component 11 and/or the second component and/or the third component and / or the fourth component can be heated up and/or kept warm quickly and efficiently, with the at least one component 11 being arranged in particular downstream of the burner 12. The burner 12 can burn a mixture, in particular to form a flame, which results in burner exhaust gas from the burner 12, which provides the burner exhaust gas. For example, the burner exhaust gas or the flame can be introduced into the exhaust gas tract 10 at an introduction point E, that is, into an exhaust gas duct 14 of the exhaust gas tract 10 through which the exhaust gas can flow. This means that the burner 12 is arranged at the introduction point E, so to speak. Like in particular 2 As can be seen, the exhaust gas from the internal combustion engine is guided via an inflow line 15 in the exhaust gas duct 14 to the introduction point E of the burner 12 and released into the exhaust gas duct 14. Of course, the inflow line 15 can be dispensed with, so that the exhaust gas from the internal combustion engine flows from the turbine into the exhaust duct 14. For example, the introduction point E is arranged upstream of the second component, upstream of the third component and upstream of the fourth component and downstream of the first component. In other words, for example, the burner 12 is arranged upstream of the second component, upstream of the third component and upstream of the fourth component and downstream of the first component. Alternative and in 2 shown, it is conceivable that the burner 12 or the introduction point E is arranged upstream of the first component 11 and in particular downstream of the turbine. The aforementioned mixture to be burned in the burner 12 or by means of the burner 12 comprises air and a preferably liquid fuel. For example, in the exemplary embodiment shown in the figures, the aforementioned fuel is used as the fuel. Alternatively or additionally, at least a portion of the air that is supplied to the burner 12 and used to form the mixture can come, for example, from the intake tract.

For example, a fuel supply path is provided which is, on the one hand, fluidly connected or connectable to the burner 12 and, on the other hand, fluidly connected to a fuel line. The fuel can flow through the fuel line from the tank to the injectors or to the fuel distribution element. In particular, the fuel supply path is fluidly connected to the fuel line at a first connection point, the first connection point being arranged downstream of the low-pressure pump and upstream of the high-pressure pump in the flow direction of the fuel flowing from the tank to the fuel distribution element or to the respective injector. At the first connection point, at least part of the fuel, in particular liquid fuel, flowing through the fuel line can be branched off from the fuel line and introduced into the fuel supply path. The fuel introduced in the fuel supply path can flow through the fuel supply path and is conducted as valuable fuel by means of the fuel supply path to and in particular into the burner 12. For example, a first valve element is arranged in the fuel supply path, by means of which an amount of fuel flowing through the fuel supply path and thus to be supplied to the burner 12 can be adjusted. For example, an electronic computing device, also referred to as a control device, is provided, by means of which the first valve element can be controlled, so that the amount of fuel flowing through the fuel supply path and to be supplied to the burner 12 can be adjusted, in particular regulated, by means of the control device via the first valve element. Preferably, the fuel supply path has a controlled pump for delivering the fuel from the tank to the burner 12.

Furthermore, for example, an air supply path is provided, via which or by means of which the burner can be supplied or is supplied with the air to form the mixture. This means that the air supply path from the air from which the Mixture is formed, can flow through. For example, a pump, also known as an air pump, is arranged in the air supply path, by means of which the air can be conveyed through the air supply path and thus conveyed towards the burner 12. For example, the low-pressure pump, also known as a low-pressure fuel pump, is referred to as a fuel pump, by means of which the fuel is conveyed through the fuel supply path and is thus conveyed towards the burner 12. The air supply path is fluidly connected to the intake tract, for example, at a second connection point. Thus, for example, a second connection point can divert at least part of the fresh air flowing through the intake tract from the intake tract and introduce it into the air supply path. The fresh air introduced into the air supply path can flow through the air supply path as the air for forming the mixture and is guided to and in particular into the burner 12 by means of the air supply path. For example, a second valve element is arranged in the air supply path, by means of which the amount of air that flows through the air supply path and thus flows through the burner 12 and is used to form the mixture can be adjusted. In this case, for example, the control device is designed to control the second valve element so that, for example, by means of the control device via the second valve element, the amount of air flowing through the air supply path and thus to be supplied to the burner 12, which is used to form the mixture, can be adjusted, in particular regulated. is. The air supply path preferably has a controlled or regulated pump for conveying air, in particular fresh air or ambient air. The air is preferably sucked in by the pump via an air filter of the air supply path and conveyed to the burner 12.

Like from the one in particular 1 , 2 and 4 can be seen, the burner 12 has a combustion chamber 16 in which the air supplied to the burner 12, also referred to as burner air, from which the mixture is formed, and the mixture comprising the liquid fuel supplied to the burner 12 are ignited and thereby closed is burned, that is, ignited during operation of the burner 12 and thereby burned. For this purpose, an ignition device 18 designed, for example, as a spark plug or glow plug or glow plug, in particular electrically operable, is provided, which is, for example, part of the burner 12. By means of the ignition device 18, at least one ignition spark can be generated in the combustion chamber 16, in particular using electrical energy or electrical current. By means of the ignition spark, the mixture is ignited in the combustion chamber 16 and subsequently burned, in particular by providing the burner exhaust gas and/or by providing the aforementioned flame. By means of the burner exhaust gas or by means of the flame, for example, the exhaust gas flowing through the exhaust tract 10, that is to say the exhaust gas flowing through the exhaust duct 14, can be heated up and/or kept warm quickly and efficiently, so that by means of the heated and/or kept warm exhaust gas (engine exhaust gas), which, for example the first component 11 and the other components flow through, are heated quickly and efficiently and / or kept warm.

The burner 12 has a first, inner swirl chamber 20, through which a first part of the air, also referred to as burner air, which is supplied to the burner 12, can flow through or flows through and causes a first swirl-shaped flow of the first part of the air, thus to Effecting a first swirl-shaped flow of the first part of the air is formed. This is to be understood in particular as meaning that the first part of the air flows in a swirl pattern through at least a first portion of the swirl chamber 20 and/or flows out in a swirl pattern from the swirl chamber 20 and/or flows in a swirl pattern into and thus in the combustion chamber 16. The inner swirl chamber 20 has, in particular, a first outflow opening 22, through which the first part of the air can flow along a first passage direction of the outflow opening 22 and thus along a first flow direction coinciding with the first passage direction. The first part of the air can be removed from the inner swirl chamber 20 into the combustion chamber 16 via the first outflow opening 22. This means that the first part of the air can flow out of the inner swirl chamber 20 via the first outflow opening 22. Furthermore, the burner 12 includes an introduction element 24, in the present case in the form of an electrically actuated injection element, through which the liquid fuel, which is supplied to the burner 12, can flow through. The introduction element 24 preferably, in particular precisely, has three outlet openings, also referred to as injection openings, through which the fuel supplied to the introduction element 24 can flow, the fuel flowing through the respective outlet openings flowing out of the introduction element 24, in particular as a whole. For example, the respective outlet openings are designed as a particularly round hole. The respective outlet opening can be flowed through by the fuel, for example along a respective, second passage direction, so that the fuel flowing through the introduction element 24 can be ejected or can exit from the introduction element 24 via the respective outlet opening and, in particular directly, can be injected into the inner swirl chamber 20 and thereby introduced. Preferably, the second passage direction is slightly inclined to the axial direction of the swirl chamber 20, the axial direction of which, for example, coincides with the aforementioned first passage direction. Furthermore, for example, the axial direction of the swirl chamber 20 coincides with a burner longitudinal axis of the burner 12, which extends elongated, for example, along its burner longitudinal axis and in particular, for example, the swirl chamber 20 and / or the combustion chamber 16 can be designed rotationally symmetrical with respect to the burner longitudinal axis. The introduction element 24 is in particular designed to eject the fuel from the outlet openings (not specified) in a clocked manner and thus to inject it in a clocked manner into the swirl chamber 20, in particular onto a surface which directly delimits the swirl chamber 20, in particular in the radial direction of the swirl chamber 20, and is designed as an inner circumferential surface 26 to spray on. In other words, the swirl chamber 20 is at least partially, in particular at least predominantly and therefore at least more than half or completely, directly delimited by the surface 26, which in the present case is an inner circumferential surface.

The respective, second passage direction of the respective outlet opening coincides with a respective, second flow direction along which the fuel can flow through the respective outlet opening and thus flow out of the introduction element 24 (injection element). The fuel can be sprayed out of the introduction element 24 via the respective outlet opening, in particular to form a respective fuel jet, and thereby injected, in particular directly, into the swirl chamber 20. For example, the respective fuel jet, whose longitudinal center axis coincides, for example, with the respective second passage direction or with the respective second flow direction, is at least essentially club-shaped or conical. In addition, for example, the insertion element 24 has a longitudinal direction or longitudinal extension or longitudinal extension direction, which runs parallel to the first passage direction and thus parallel to the first flow direction and parallel to the axial direction of the inner swirl chamber 20, in particular with the first passage direction and thus with the first flow direction and thus in particular coincides with the axial direction of the inner swirl chamber 20. For example, the respective second passage direction runs perpendicularly or, in this case, obliquely to the first passage direction and thus to the first flow direction and to the axial direction of the inner swirl chamber 20 and the first outflow opening 22.

The inner swirl chamber 20 is at least partially, in particular at least predominantly and therefore more than half or completely, formed or limited by a component 28 of the burner 12, so that component 28 also forms or delimits the first outflow opening 22, in particular directly. The component 28 thus forms, for example, the surface 26. The component 28 is also referred to as a prefilmer or film layer.

The burner 12 further has an outer swirl chamber 30, which surrounds at least one length region and in the present case also the first outflow opening 22 in the circumferential direction of the inner swirl chamber 20, which extends around the axial direction of the inner swirl chamber 20, in particular completely circumferentially. For example, the component 28 has a partition 32 which is arranged between the swirl chambers 20 and 30 in the radial direction of the inner swirl chamber 20 and thus in the radial direction of the outer swirl chamber 30, the radial direction of which coincides with the radial direction of the swirl chamber 20. As a result, the swirl chambers 20 and 30, whose axial directions coincide, are separated from one another in the radial direction of the swirl chambers 20 and 30 by the partition 32. The axial direction of the swirl chamber 20 coincides with the axial direction of the swirl chamber 30, with the radial direction of the swirl chamber 20 coinciding with the radial direction of the swirl chamber 30. A second part of the air supplied in the burner 12 can flow through the outer swirl chamber 30 and is designed to cause a second swirl-shaped flow of the second part of the air. This means that the second part of the air flows through the swirl chamber 30 in a swirl pattern and/or flows out of the swirl chamber 30 in a swirl pattern and/or flows in a swirl pattern into and thus in the combustion chamber 16. In particular, it is preferably provided that the second part of the air flows in a swirl pattern through at least a second portion of the outer swirl chamber 30 and/or flows out in a swirl pattern from the swirl chamber 30 and/or flows in a swirl pattern into and thus in the combustion chamber 16.

The outer swirl chamber 30 has, in particular precisely, a second outflow opening 34 which can flow through the second part of the air flowing through the outer swirl chamber 30, in particular along a third flow direction, the third passage direction of which coincides with the third flow direction, along which the outflow opening 34 of the second part of the air flowing through the swirl chamber 30 can flow through, in the present case coinciding with the axial direction of the swirl chamber 30 and thus the axial direction of the swirl chamber 20. The third direction of passage coincides with the third direction of flow along which the outer Second part of the air flowing through the swirl chamber 30 flows through or can flow through the outflow opening 34. This means in particular that the first passage direction coincides with the third passage direction and the first flow direction coincides with the third flow direction, so that in the present case the first flow direction, the third flow direction, the first passage direction and third passage direction coincide with the axial direction of the swirl chamber 20 and with the axial direction the swirl chamber 30 coincide. In the flow direction of the air flowing through the swirl chambers 20 and 30, in particular the outflow opening 22 and 34, the second outflow opening 34 is arranged downstream of the first outflow opening 22 and in particular is arranged or connected in series or in series with the outflow opening 22, so that the second outflow opening 34 the second part of the air, the first part of the air and the fuel can flow through. In particular, due to the swirl-shaped first flow, the first part of the air is already mixed with the fuel in the swirl chamber 20, in particular to form a partial mixture. The partial mixture can flow through the outflow opening 22 and thus flow out of the swirl chamber 20 and then flow through the second outflow opening 34 and is mixed with the second part of the air, in particular due to the advantageous, second swirl-shaped flow, whereby the mixture is prepared in a particularly advantageous manner, i.e. that Partial mixture is particularly advantageously mixed with the second part of the air.

It can be seen that the swirl chamber 30 is at least partially, in particular at least predominantly and therefore at least more than half or completely, limited in the radial direction of the respective swirl chamber 20, 30 inwards by the component 28, in particular by the partition 32 is. In particular, the swirl chamber 20 is limited to the outside in the radial direction of the respective swirl chamber 20, 30 at least partially, in particular at least predominantly or completely, by the component 28, in particular by the partition 32. In the radial direction of the respective swirl chamber 20, 30 towards the outside, the outer swirl chamber 30 is at least partially, in particular at least predominantly or completely, limited by a component 36 of the burner 12. In particular, the swirl chamber 20 is at least partially delimited towards the outside in the radial direction of the swirl chamber 20, 30 by the surface 26, in particular directly. The swirl chamber 30 is delimited, in particular directly, in the radial direction of the respective swirl chamber 20, 30 towards the outside at least partially by a second surface 38, which is in the present case designed as an inner circumferential surface, the second surface 38 being formed in particular by the component 36.

In the exemplary embodiment shown in the figures, it is provided that the component 36 and the component 28 are components designed separately from one another and in particular connected to one another. The component 28 is at least partially, in particular at least predominantly, arranged in the component 36. The second outflow opening 34 is, for example, at least partially, in particular at least predominantly and therefore at least more than half or completely, limited or formed by the component 36 or the second outflow opening 22 is, for example, partly through the component 36 and partly through the component 28, in particular directly, limited or formed, in particular with regard to the smallest or smallest flow cross section of the outflow opening 34 through which the second part of the air can flow.

Particularly good looking 1 until 4 It can be seen that the combustion chamber 16 is at least partially, in particular at least predominantly or completely, delimited, in particular directly, by a chamber element 40 of the burner 12. In particular, the chamber element 40 has a surface 42 designed as an inner circumferential surface, through which the combustion chamber 16 is at least partially directly delimited. In particular, the combustion chamber 16 is at least partially, in particular at least predominantly completely, delimited towards the outside in the radial direction of the respective swirl chamber 20, 30, preferably directly by the surface 42.

In the exemplary embodiments shown in the figures, how in particular 3 can be seen, the chamber element 40 has a wall 44, which is spaced from the outflow openings 22 and 34 in the axial direction of the respective swirl chamber 20, 30 and thus in the first or third flow direction, the combustion chamber 16 being in the axial direction of the respective swirl chamber 20, 30 and thereby in the first or third flow direction, i.e. in a boundary direction that runs parallel to the axial direction in the respective swirl chamber 20, 30 and points away from the swirl chambers 20 and 30 through the wall 44, in particular through a surface 46 of the wall 44 and thus of the Chamber element 40 is limited. It is conceivable that the surfaces 42 and 46 are components of an overall surface of the chamber element 40 on the inner circumference. How particularly good looking 3 can be seen, the wall 44 is penetrated by several through openings 48, which completely penetrate the wall 44. At In the exemplary embodiment shown in the figures, the through openings 48 are arranged successively and spaced apart from one another in the circumferential direction extending around the respective axial direction of the respective swirl chamber 20, 30 and are in particular arranged evenly distributed. Furthermore, for example, the through openings 48 are circular and thus designed as circles, the centers of which lie on another circle, the center of which lies on the axial direction of the respective swirl chamber 20, 30. In particular, the swirl chamber 30 is designed to be rotationally symmetrical with respect to its axial direction and thus in particular with respect to the burner's longitudinal axis.

The burner exhaust gas from the combustion chamber 16 can flow through the through openings 48 and thus flow out of the combustion chamber 16 via the through openings 48 and, in particular, flow into the exhaust gas tract 10, that is, into the exhaust gas duct 14, at the introduction point E1.

In 4 it can be seen that the in 4 In summary, swirl-shaped flows, denoted by 50, run in a swirl-shaped manner in the combustion chamber 16, such that the swirl-shaped flows run helically or helically around the respective axial direction of the respective swirl chamber 20, 30 and thus around the longitudinal axis of the burner. A first exhaust part of the burner exhaust gas can, for example, flow through the through opening 48 and thereby flow into the exhaust system, in particular into the exhaust duct 14. A second exhaust part of the burner exhaust gas, for example, initially flows against the wall 44 and is thereby deflected by means of the wall 44 and in particular deflected back (arrow 52), in particular in the direction of the surface 42 and / or the outflow opening 34, whereupon, for example, at least part of the second exhaust part Through opening 48 can flow through. This allows a particularly advantageous mixture preparation to be achieved by means of the existing backflow (arrow 52) in the combustion chamber 16.

Particularly good looking 4 , 5 and 6 the component 28 and the component 36 can be seen. For example, the component 28 is at least partially inserted into the component 36. The component 28 and the component 36 form a swirl generating device 54 of the burner 12. The swirl generating device 54 comprises a first swirl generator 56, which are also referred to as first swirl generating elements and are designed, for example, as first guide vanes. The first swirl generators 56 are the first swirl generators of the inner swirl chamber 20. In addition, the component 28 has the first swirl generators 56. The swirl generating device 54 also includes second swirl generators 58, which are also referred to as second swirl generating elements. In particular, for example, the second swirl generators 58 are second guide vanes. The second swirl generators 58 are second swirl generators of the outer swirl chamber 30. In addition, it is provided here that the component 36 has the second swirl generators 58. By means of the first swirl generator 56, the first swirl-shaped flow of the first part of the air is generated in the inner swirl chamber 20, and by means of the second swirl generator 58, the second swirl-shaped flow of the second part of the air is generated in the outer swirl chamber 30. The swirl generators 56 and 58 are arranged successively and in particular at a distance from one another in the circumferential direction extending around the axial direction of the respective swirl chamber 20, 30, in particular in such a way that swirl channels 60 and 62 are arranged in the circumferential direction of the respective swirl chamber 20, 30 between the swirl generators 56 and 58 are. The swirl channels 60 and 62 are therefore arranged successively and at a distance from one another in the circumferential direction of the respective swirl chamber 20, 30 and are separated from one another in such a way that one of the respective swirl generators 56 and 58 is arranged in the circumferential direction of the respective swirl chamber 20, 30 between two of the swirl channels 60 and 62 is. It can be seen that the respective swirl channel 60, 62 is directly delimited on both sides in the circumferential direction of the respective swirl chamber 20, 30 by two of the swirl generators 56 and 58, respectively. In other words, for example, the respective swirl channel is directly delimited on both sides in the circumferential direction of the respective swirl chamber 20, 30 by respective surfaces 64, in particular of the component 28. Accordingly, the respective swirl channel 62 is directly delimited on both sides in the circumferential direction of the respective swirl chamber 20, 30 by respective surfaces 65, in particular of the component 36. The component 28 or the inner swirl chamber 20 is also referred to as a prefilmer or film layer.

In particular, the swirl generators 56 form a first swirl generating device 55 of the inner swirl chamber 20, wherein the first swirl-shaped flow of the first part of the air can be brought about or is brought about by means of the swirl generating device 55. Furthermore, the second swirl generators 58 form a second swirl generating device 57 of the outer swirl chamber 30, wherein the second swirl-shaped flow of the second part of the air can be or is effected by means of the second swirl generating device 57. Furthermore, it can be seen that the swirl generating devices 55 and 57 are components of the swirl generating device 54. The swirl generating device 55 is formed by the component 28, and the swirl generating device 57 is formed by the component 36.

The first outflow opening 22 ends, for example in the flow direction of the first part of the air flowing through the first outflow opening 22, at a preferably specifically processed, sharp-edged end edge K ( 6 ), which is formed by an atomizer lip 67, in particular designed as a solid body, which can taper in the flow direction of the first part of the air flowing through the first outflow opening 22 up to the end edge K and ends, for example, at the end edge K. In particular, the atomizer lip 67 is part of the component 28 or is formed by the component 28. In other words, in order to be able to heat up the first component 11, which is designed, for example, as an exhaust gas aftertreatment device or as an exhaust gas aftertreatment system, particularly quickly and efficiently, in particular even when the exhaust gas from the internal combustion engine has only a low temperature, it is preferably provided that the first outflow opening 22 in the flow direction of the first part of the air flowing through the first outflow opening 22 and thus in the flow direction of the fuel flowing through the first outflow opening 22 ends at the preferably specifically processed and therefore sharp or razor-sharp end edge K, which is formed by the atomizer lip 67, which is in particular designed as a solid body, which preferably tapers in the flow direction of the first part of the air flowing through the first outflow opening 22 and thus in the flow direction of the fuel flowing through the first outflow opening 22, in particular up to the end edge K and in particular ends at the end edge K. This means that the atomizer lip 67 has a taper that tapers in the first flow direction and thus in particular towards the combustion chamber 16, which ends, in particular, only at the end edge K. As a result of this and in particular due to the targeted processing of the end edge K, the taper or the atomizer lip 67 is sharp-edged. Expressed again in other words, the atomizer lip 67 ends with a sharp edge, which means that a particularly advantageous mixture preparation can be achieved.

In the present case, the particularly razor-sharp end edge K is formed by the atomizer lip 67, which in the present case is formed by the component 28. In particular, the atomizer lip 67 tapers in the flow direction of the first part of the air flowing through the first outflow opening 22 and thus in the flow direction of the fuel flowing through the first outflow opening 22 up to the end edge K and ends at the end edge K.

It is particularly conceivable that the component 28, in particular the inner swirl chamber 20 in the radial direction of the swirl chamber 20 towards the outside and at least partially and directly delimiting the inner peripheral surface (surface 26), is a film layer or as a film layer between the swirl chambers 20 and 30 and thus between the swirl-shaped and therefore twisted flows, also known as air flow. In particular, it is conceivable that the inner peripheral surface or the film layer is formed by the aforementioned partition 32. In this case, by means of the introduction element 24, the fuel flowing through the outlet opening and thus emerging, in particular sprayed out, from the introduction element 24 is applied, in particular as a film also referred to as a fuel film, to the film layer, in particular to the surface 26, or is atomized onto the film layer. As a result of centrifugal forces resulting from the swirl-shaped, first flow of the first part of the air, the fuel that has emerged from the introduction element 24, in particular that has been sprayed out, and is thereby introduced, in particular directly, into the inner swirl chamber 20, in particular injected, that is to say injected, is in particular higher than the fuel previously injected said film onto the film layer, in particular onto the surface 26, and flows or flows downstream to the first outflow opening 22 and thus to the end edge K. As a result, the fuel is applied to the atomizer lip 67 and conveyed or transported to the end edge K. The first outflow opening 22 preferably ends at the preferably razor-sharp end edge K, which here has or provides only a small area due to the taper described above, so that no excessively large droplets of fuel can form at the end edge K. Due to the appropriate design of the atomizer lip 67 and in particular the end edge K, only tiny droplets of the fuel tear off at the end edge K. In other words, only particularly small, i.e. tiny, droplets arise from the aforementioned fuel film at the end edge K, which break off at the end edge K, in particular from the atomizer lip 67 or from the component 28, and have a correspondingly large surface area. This effect leads to a particularly low-soot combustion of the mixture in the combustion chamber 16. As a result, tiny droplets of fuel can be produced without complex, high injection pressures of the fuel and without costly injection elements, so that on the one hand the costs of the burner 12 can be kept particularly low. On the other hand, particularly small droplets of fuel can be generated, so that even very small outputs of the burner 12 can be represented.

How particularly good looking 5 and 6 in conjunction with 1 and 4 can be seen, the first part of the air of the inner swirl chamber 20 can be fed in the radial direction of the other swirl chamber from the outside to the inside, and can therefore be introduced into the inner swirl chamber 20 from the outside to the inside in the radial direction of the inner swirl chamber 20. The second part of the air of the outer swirl chamber 30 can be fed in the radial direction of the outer swirl chamber 30 from the outside to the inside, and can therefore be introduced into the outer swirl chamber 30 from the outside inwards in the radial direction of the outer swirl chamber 30. This is to be understood in particular as meaning that the first part of the air or the second part of the air can be introduced into the respective swirl chamber 20, 30 in a respective flow plane, that is to say in a respective inflow direction running in the respective flow plane, the flow plane being perpendicular to the axial direction of the respective swirl chamber 20, 30. This is implemented in the burner 12 in such a way that the first part of the air can be introduced into the swirl chamber 20 via the swirl channels 60, and can therefore be fed to the swirl chamber 20, whereby the second part of the air can be fed to the outer swirl chamber 30 via the swirl channels 62, i.e. in the outer swirl chamber 30 can be introduced, wherein the respective swirl channel 60 can be flowed through by the first part of the air in the said flow plane and viewed in the radial direction of the swirl chamber 20 from the outside to the inside, and the respective swirl channel 62 in the mentioned flow plane and thereby Viewed in the radial direction of the swirl chamber 30, the second part of the air can flow through from the outside to the inside.

In the exemplary embodiment shown in the figures, it is in particular provided that the respective swirl channel 60 can be flowed through in a fourth flow direction by a respective part of the first part of the air and thereby in the radial direction of the swirl chamber 20 from the outside to the inside, in order to thereby flow through the first part to supply the air to the swirl chamber 20, thus introducing it into the swirl chamber 20, the fourth flow direction running in a first flow plane which runs perpendicular to the axial direction of the swirl chamber 20. As a result, a respective part of the second part of the air can flow through the respective swirl channel 62 in a fifth flow direction and thereby in the radial direction of the swirl chamber 30 from the outside to the inside, in order to thereby supply the second part of the air to the swirl chamber 30, i.e. into the swirl chamber 30 to initiate, the fifth flow direction running in a second flow plane, which runs perpendicular to the axial direction of the swirl chamber 30. It is conceivable that the first flow plane and the second flow plane are spaced apart from one another, particularly in the axial direction of the respective swirl chamber 20, 30, or the flow planes coincide.

7 shows a diagram on whose abscissa 68 the time is plotted. An electrical voltage and an electrical current of the insertion element are plotted on the ordinate 70, which is controlled, for example, with the voltage and the current.

In order to realize a particularly advantageous operation of the burner 12, the introduction element 24 (injection element) is designed to introduce the fuel into the inner swirl chamber 20 in a clocked manner, in particular to inject it. In other words, for example, in a method for operating the burner 12, it is provided that the insertion element 24 is operated in a clocked manner, that is to say in a clocked operation. This clocked operation is over 7 illustrated. One in the in 7 Diagram shown plotted curve 72 illustrates the electrical current, also referred to as control current, over time, the insertion element 24 being controlled, for example by means of an electronic computing device, in that the insertion element 24 is supplied with the control current (curve 72). A timing of the drive current is illustrated by a curve 74. By supplying the insertion element 24 with the control current, the following is achieved in particular: Off 8th It can be seen that the insertion element 24 has, for example, a housing 75, through which, for example, the respective outlet opening is formed or limited, in particular directly. The insertion element 24 has a valve element 76 designed, for example, as a ball, which is positioned relative to the housing 75, in particular translationally, between an in 8th shown closed position and at least one open position is movable. In the closed position, the preferably three outlet openings of the introduction element 24 are fluidically blocked by means of the valve element 76, so that the introduction of the fuel into the inner swirl chamber 20 caused by the introduction element 24 does not occur, that is, so that the introduction element 24 does not spray out any fuel and in particular no fuel into it inner swirl chamber 20 injected. In the open position, however, the valve element 76 releases the respective outlet opening, so that the fuel can flow through the introduction element 24 and thereby flow through the outlet openings, in particular in the second flow direction, also referred to as the introduction direction or ejection direction, so that the fuel can flow in the respective, also known as Insertion direction designated injection direction from the housing 75 and thereby sprayed out of the insertion element 24. The second flow direction can be inclined at an angle of 18° to 40° to the first flow direction. In order to move the valve element 76 from the closed position to the open position and, in particular during a To keep the control period, in particular without interruption, in the open position, the insertion element 24 is supplied with the control current and thereby controlled. The timing 74 of the control current causes the insertion element 24 to carry out a number of insertion processes 78 within a particular predeterminable or predetermined period of time, which, as shown 7 is particularly easy to recognize, follow one another in time and are spaced apart in time, so that between two respective, directly successive introduction processes 78, the introduction element 24 does not spray out fuel. The insertion processes 78 are equally spaced apart in time in pairs. This means that the insertion processes 78 are spaced apart in pairs by the same time interval. This is realized, for example, in such a way that the insertion element 24 is supplied with the control current during the respective control period, with a respective pause time 80 lying between two directly successive insertion processes 78 and thus in time between two directly successive control durations, which corresponds to the aforementioned time interval . During the pause time 80, the fuel is not introduced into the inner swirl chamber 20 by the introduction element 24, in particular in such a way that the introduction element 24 is not supplied during the respective pause time 80, in particular continuously.

Particularly good looking 7 It can be seen that the insertion processes 78 have a frequency also referred to as a clock frequency within the time period, and are therefore carried out at a frequency also referred to as a clock frequency. The clock frequency is preferably as high as possible, and it is preferably provided that the clock frequency is more than 100 Hertz. It is therefore preferably provided that more than 100 insertion processes 78 are carried out per second within the period of time, with it preferably being provided that the drive current is kept low. As a result, the aforementioned film formed by the fuel can be produced particularly uniformly on the film layer, so that particularly small fuel droplets can subsequently be produced.

9 shows part of the component 28, i.e. the film layer, in a schematic sectional view. In 9 is illustrated by an arrow 82 a flow of the preferably liquid fuel, which in 9 is designated 84 and injected into the inner swirl chamber 20 by means of the insertion element 24 and in particular sprayed onto the surface 26. Furthermore, in 9 an arrow 86 illustrates a flow direction of the air flowing through the inner swirl chamber 20. If, for example, the introduction element 24 were not operated in a clocked manner, but rather sprayed out the fuel 84 at least substantially continuously and thus injected it at least substantially continuously into the inner swirl chamber 20, it would, as in 9 is shown, there is a wave-shaped flow of the fuel 84 on the surface 26 and thus on the film layer (component 28), this wave-shaped flow of the fuel 84 in 9 has waves designated 88. As a result, for example, it would be at an in 9 At the point designated 90 on the shaft 88, droplets break off, which can result in undesirably large droplets being formed from the fuel 84. Furthermore, a wave 88 could reach the end edge K, so that undesirably large droplets could arise. However, this can now be avoided by the clocked operation of the introduction element 24, so that waves 88 can be avoided and the injected fuel 84 forms a uniform, in particular essentially the same height, fuel film on the surface 26, thereby ensuring efficient and low-emission operation of the burner 12 can be represented.

Reference symbol list

10

Exhaust tract

11

component

12

burner

14

exhaust duct

15

Inflow line

16

combustion chamber

18

Ignition device

20

inner swirl chamber

22

first outflow opening

24

Injection element

26

surface

28

Component

30

outer swirl chamber

32

partition wall

34

second outflow opening

36

Component

38

surface

40

Chamber element

42

surface

44

wall

46

surface

48

Passage opening

50

currents

52

Arrow

54

Swirl generating device

55

first swirl generating device

56

first swirl generator

57

second swirl generating device

58

second swirl generator

60

first swirl channel

62

second swirl channel

64

surface

65

surface

67

atomizer lip

68

abscissa

70

ordinate

72

Course

74

Course

75

Housing

76

Valve element

78

Insertion procedures

80

break time

82

Arrow

84

fuel

86

Arrow

88

Wave

90

Job

E

Induction point

K

end edge

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 3729861 C2 [0003]
• DE 112012001594 T5 [0003]
• DE 112012001599 T5 [0003]
• DE 19627760 C2 [0004]
• DE 19803879 C1 [0004]

Claims (10)

Burner (12) for an exhaust gas tract (10) through which exhaust gas from an internal combustion engine of a motor vehicle can flow, with: - a combustion chamber (16), in which a mixture comprising air and fuel (84) is to be ignited and thereby burned, - an inner swirl chamber (20) through which a first part of the air can flow, which has a first swirl generating device (55), by means of which a swirl-shaped flow (50) of the first part of the air can be brought about, and one of which the inner swirl chamber (20) through which the first part of the air can flow through, a first outflow opening (22) through which the first part of the air can be removed from the inner swirl chamber (20), - an introduction element (24) through which the fuel (84) can flow, by means of which the fuel (84) can be introduced into the inner swirl chamber (20), the first outflow opening (22) of which also contains the fuel (84) discharged from the introduction element (24). ) can be flowed through, and - an outer swirl chamber (30) surrounding at least one length region of the inner swirl chamber (20) in the circumferential direction of the inner swirl chamber (20), through which a second part of the air can flow, which has a second swirl generating device (57), by means of which a swirl-shaped flow (50 ) of the second part of the air can be effected, and one of the second part of the air flowing through the outer swirl chamber (30), of which the fuel (84) flowing through the first outflow opening (22) and of which the inner swirl chamber (30) and the first The first part of the air flowing through the outflow opening (22) has a second outflow opening (34) through which the parts of the air and the fuel (84) can be introduced into the combustion chamber (16), the introduction element (24) being designed to Fuel (84) is introduced into the inner swirl chamber (20) in a clocked manner. burner (12). Claim 1 , characterized in that the introduction element (24) is designed to introduce the fuel (84) into the inner swirl chamber (20) at a frequency of at least 50 Hertz. burner (12). Claim 1 , characterized in that the introduction element (24) is designed to introduce the fuel (84) into the inner swirl chamber (20) at a frequency of at least 80 Hertz. burner (12). Claim 1 , characterized in that the introduction element (24) is designed to introduce the fuel (84) into the inner swirl chamber (20) at a frequency of at least or exactly 100 Hertz. Burner (12) according to one of the preceding claims, characterized in that the introduction element (24) has at least one outlet opening through which the fuel (84) flowing through the introduction element (24) can flow, through which the fuel (84) flowing through the outlet opening exits the introduction element (24) can be removed and thereby introduced into the inner swirl chamber (20). burner (12). Claim 5 , characterized in that the outlet opening can be flowed through in an introduction direction by the fuel (84) flowing through the outlet opening, the introduction direction running obliquely to the axial direction of the inner swirl chamber (20). Burner (12) according to one of the preceding claims, characterized in that the first part of the air can be supplied to the inner swirl chamber (20) in the radial direction of the inner swirl chamber (20) from the outside to the inside. Burner (12) according to one of the preceding claims, characterized in that the second part of the air can be supplied to the outer swirl chamber (30) in the radial direction of the outer swirl chamber (30) from the outside to the inside. Method for operating a burner (12) according to one of the preceding claims, wherein the fuel is introduced into the inner swirl chamber (20) in a clocked manner by means of the introduction element (24). Motor vehicle, with an internal combustion engine, by means of which the motor vehicle can be driven, and with an exhaust gas tract (10) through which exhaust gas from the internal combustion engine can flow, which has at least one burner (12) according to one of the preceding claims.

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