METHOD FOR OPERATING A BURNER OF A MOTOR VEHICLE

Description

[0001] The invention relates to a method for operating a burner of a motor vehicle having an exhaust tract through which exhaust gas from an internal combustion engine can flow.

[0002] Motor vehicles with internal combustion engines and exhaust systems, also known 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 the combustion engine, can flow through the respective exhaust tract. In certain operating states or situations of the respective internal combustion engine, a high exhaust gas temperature may be desirable, for example, in order to quickly heat up and / or keep warm an exhaust gas aftertreatment device arranged in the exhaust tract. However, in these operating states or situations, the exhaust gas temperature is insufficiently high.

[0003] DE 10 2006 015 841 B3 discloses a burner for a motor vehicle having an exhaust tract through which exhaust gas from an internal combustion engine can flow. The burner has a combustion chamber in which a mixture comprising air and a liquid fuel is to be ignited and thereby burned. An inner swirl chamber is provided through which a first portion of the air flows and which causes a swirling flow of the first portion of the air. An introduction element having an outlet opening is provided in the inner swirl chamber, by means of which introduction element fuel can be introduced into the inner swirl chamber via the outlet opening. The inner swirl chamber is surrounded by an outer swirl chamber through which a second portion of the air flows and which causes a swirling flow of the second portion of the air.The inner swirl chamber has a first outflow opening and the outer swirl chamber has a second outflow opening through which the parts of the air and the fuel can be introduced into the combustion chamber. The document WO2010 / 022747A1 represents further prior art.

[0004] The object of the present invention is to provide a method for operating a burner of a motor vehicle so that a particularly advantageous operation of the burner can be realized.

[0005] This object is achieved by a method having the features of patent claim 1. Advantageous embodiments with expedient further developments of the invention are specified in the remaining claims.

[0006] A first aspect of the invention relates to a method for operating a burner of a motor vehicle having an exhaust tract through which exhaust gas from an internal combustion engine, also referred to as an internal combustion engine, of a motor vehicle can flow. This means that the motor vehicle, which can preferably be designed as a motor vehicle and very preferably as a passenger car, in its fully manufactured state has the internal combustion engine and the exhaust tract and can be driven by means of 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 of the internal combustion engine.The exhaust gas can flow out of the respective combustion chamber and 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 tract. The exhaust gas aftertreatment element is, for example, a catalytic converter, in particular an SCR catalytic converter, wherein, for example, selective catalytic reduction (SCR) can be catalytically supported and / or effected by means of the SCR catalytic converter. During selective catalytic reduction, any nitrogen oxides contained in the exhaust gas are at least partially removed from the exhaust gas by reacting the nitrogen oxides with ammonia to form nitrogen and water during selective catalytic reduction. The ammonia is provided, for example, by a reducing agent, in particular a liquid one.Furthermore, the exhaust gas aftertreatment element can be or comprise a particle filter, in particular a diesel particle filter, by means of which particles contained in the exhaust gas, in particular soot particles, can be filtered out of the exhaust gas.

[0007] The burner has a combustion chamber in which a mixture comprising air and a liquid fuel can be ignited and thereby burned. The combustion of the mixture, in particular in the combustion chamber, produces exhaust gas from the burner, the exhaust gas from which is also referred to as burner exhaust gas. The burner exhaust gas can, for example, flow out of the burner chamber and into the exhaust tract, in particular at an inlet point which is arranged, for example, upstream of the component in the flow direction of the exhaust gas of the internal combustion engine flowing through the exhaust tract. As a result, the burner exhaust gas can, for example, flow through the component, whereby the component can be heated up, i.e., warmed up.Furthermore, it is conceivable for the burner exhaust gas to flow out of the burner chamber and into the exhaust tract and thereby be mixed with the exhaust gas of the internal combustion engine flowing through the exhaust tract 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, this makes it possible to achieve a particularly high temperature of the exhaust gas of the internal combustion engine or of the gas, also referred to as the exhaust gas temperature. The high exhaust gas temperature can heat the component because the exhaust gas or the gas flows through the component. Thus, for example, the exhaust gas from the combustion chamber is introduced into the exhaust tract at the aforementioned inlet point 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 arranged in the combustion chamber, by means of which, for example, at least one ignition spark for igniting the mixture can be provided, i.e., generated, in particular in the combustion chamber and / or using electrical energy or current. The ignition device is, for example, a glow plug or a spark plug.

[0008] The burner has an inner swirl chamber through which a first portion of the air forming the mixture flows and which causes a swirling flow of the first portion of the air. This inner swirl chamber is thus preferably arranged upstream of the combustion chamber in the flow direction of the first portion of the air flowing through the inner swirl chamber. The inner swirl chamber has, in particular, a first outflow opening through which the first portion of the air flowing through the inner swirl chamber flows, via which the first portion of the air flowing through the first outflow opening can be discharged from the inner swirl chamber and, for example, introduced into the combustion chamber.The feature that the inner swirl chamber causes or can cause a swirling 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 swirl chamber in a swirling manner, thus flowing through at least a longitudinal region of the swirl chamber in a swirling manner and / or the first part of the air only develops its swirling 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 swirling manner via the first outflow opening and / or flows into the combustion chamber in a swirling manner, so that it is very preferably provided that the first part of the air has its swirling flow at least in the combustion chamber.

[0009] The burner also has an introduction element, in particular an injection element, which has at least or exactly one outlet opening through which the liquid fuel can flow. The outlet opening is arranged in the inner swirl chamber, such that the introduction element, in particular the injection element, or a channel of the introduction element through which the liquid fuel can flow, opens into the inner swirl chamber via the outlet opening. By means of the introduction element, the fuel flowing through the outlet opening can be introduced, in particular injected, via the outlet opening, in particular directly, into the inner swirl chamber, such that the first outlet opening can also be flowed through by the liquid fuel that has exited, in particular sprayed out, from the injection element via the outlet opening and is thereby introduced, in particular injected, in particular directly, into the inner swirl chamber.This means in particular that the first part of the air and the fuel flow through the first outflow opening along a common, first flow direction and can thereby flow out of the inner swirl chamber.

[0010] Furthermore, the burner comprises an outer swirl chamber which surrounds at least a longitudinal region of the inner swirl chamber and thereby 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, around the aforementioned first flow direction, which coincides, for example, with the axial direction of the inner swirl chamber and thus of the first outflow opening. It is preferably provided that the inner swirl chamber ends at the first outflow opening or at the end thereof 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, thus in the axial direction of the inner swirl chamber and thus of the first outflow opening.A second portion of air can flow through the outer swirl chamber and is designed to cause a swirling flow of the second portion of air. This is to be understood in particular that the second portion of air flows in the outer swirl chamber, thus flowing in a swirling manner through at least a portion or length of the outer swirl chamber, and / or the second portion of air has its swirling flow in a second flow region arranged downstream of the outer swirl chamber in the flow direction of the second portion of air flowing through the outer swirl chamber, which second flow region coincides, for example, 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.In other words, it is conceivable that the second part of the air flows out of the outer swirl chamber in a swirl-like manner and / or flows into the combustion chamber in a swirl-like manner, so that it is preferably provided that the second part of the air has its swirl-like flow at least in the combustion chamber.

[0011] The outer swirl chamber has, in particular precisely, a second outflow opening through which the second part of the air flowing through the outer swirl chamber, the fuel flowing through the first outflow opening, and the first part of the air flowing through the inner swirl chamber and the first outflow opening can flow, and which is arranged, for example, downstream of the first outflow opening in the flow direction of the parts and the fuel, via which second outflow opening the second part of the air can be discharged from the outer swirl chamber and the parts of the air and the fuel can be introduced into the combustion chamber. In particular, the parts of the air and the fuel can flow through the second outflow opening along a second flow direction and thus flow into the combustion chamber via the second outflow opening, wherein, for example, the second flow direction runs parallel to the first flow direction or coincides 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, thus coinciding with the axial direction of the outer swirl chamber, so that it is preferably provided that the axial direction of the inner swirl chamber corresponds to the axial direction of the outer swirl chamber, or vice versa. 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 radial direction of the respective swirl chamber runs perpendicular to the respective axial direction of the respective swirl chamber.For example, since the second outflow opening is arranged downstream of the first outflow opening along the respective flow direction, i.e., in the flow direction of the respective portion 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 arranged in the outer swirl chamber. In particular, it is conceivable that the outer swirl chamber, particularly in the flow direction of the second portion of the air flowing through the second outflow opening, ends at the second outflow opening, particularly at its end.

[0012] For example, to generate the respective swirling flow, the respective swirl chamber can have at least one or more swirl generators, by means of which the respective swirling flow can be generated or is generated. In particular, the respective swirl generator is arranged in the respective swirl chamber. In particular, the swirl generator can be a guide vane, for example, by means of which, for example, the respective part, i.e., the respective air forming the respective part, is deflected at least or exactly once, in particular by at least or exactly 70 degrees, in particular by approximately 90 degrees, i.e., for example, by 70 to 90 degrees.In particular, a swirling flow is understood to mean a flow which extends in a swirling or at least substantially helical or helical manner 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. In this case, for example, the respective axial direction of the respective outflow opening coincides with the respective axis of the respective swirl chamber. The respective outflow opening is also referred to, for example, as a respective nozzle, the cross-section of which the respective part of the air can flow through, however, does not necessarily have to taper along the respective flow direction.Thus, for example, the second outflow opening is also referred to as the outer nozzle or second nozzle, while the first outflow opening is also referred to as the inner nozzle or first nozzle.

[0013] By causing the respective swirling flow, the air can be mixed with the liquid fuel in a particularly advantageous manner, particularly over a short mixing distance, particularly in the combustion chamber, so that particularly advantageous mixture preparation is achieved, i.e. the mixture can be formed in a particularly advantageous manner. In particular, the fuel can initially be mixed particularly well with the first part of the air, particularly in the inner swirl chamber, particularly due to the swirling flow of the first part, particularly in the inner swirl chamber. In addition, the fuel and, for example, also the first part already mixed with the fuel can be mixed particularly advantageously with the second part of the air, particularly in the outer swirl chamber and / or in the combustion chamber, since the second part of the air also has an advantageous, swirling flow.Overall, due to the swirling flows, the air and fuel components can be mixed particularly advantageously, so that advantageous mixture preparation can be achieved.

[0014] In order to be able to heat up the component, 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 of the internal combustion engine has only a low temperature, it can preferably be provided that the first outflow opening (first or inner nozzle) ends in the flow direction of the first part of the air flowing through the first outflow opening and thus in the flow direction of the fuel flowing through the first outflow opening at a specifically machined and thus sharp or knife-sharp end edge, which is formed by an atomizer lip designed, in particular, as a solid body,which tapers in the flow direction of the first portion of air flowing through the first outflow opening, and thus in the flow direction of the fuel flowing through the first outflow opening, up to the end edge and ends at the end edge. This means that the atomizer lip has a taper that tapers in the first flow direction and thus in particular towards the combustion chamber, and which, in particular, only ends at the end edge. As a result of this, and in particular due to the targeted machining of the end edge, the taper or the atomizer lip has sharp edges. In other words, the atomizer lip ends with sharp edges, which allows for particularly advantageous mixture preparation.

[0015] For example, the mixture is burned in the combustion chamber to form a flame, wherein the fuel can be advantageously mixed with the air in particular by the swirling flows, and wherein the flame in the combustion chamber can be advantageously stabilized in particular due to the swirling flows. For this purpose, combustion-induced bursting of vortices can be generated in particular by the swirling flows. For this purpose, for example, the air flowing into the combustion chamber is first deflected in the respective swirl chamber by approximately 70 degrees or approximately 90 degrees, in particular in a range from 70 degrees to 90 degrees, which can be achieved, for example, by the respective swirl generator. The inner swirl chamber and the outer swirl chamber form, for example, a swirl chamber, also referred to as an overall swirl chamber, which in the invention is divided into the inner swirl chamber and the outer swirl chamber.Preferably, the inner swirl chamber and the outer swirl chamber are separated from one another by a partition wall, which is in particular designed as a solid body, in particular in the radial direction of the respective swirl chamber. It is conceivable for the partition wall to surround at least the aforementioned longitudinal region of the inner swirl chamber in the circumferential direction of the inner swirl chamber running around the axial direction of the inner swirl chamber, in particular completely circumferentially, so that, for example, at least the longitudinal region of the inner swirl chamber is formed or delimited outwards, in particular directly, by the partition wall in the radial direction of the inner swirl chamber. Furthermore, it is conceivable for at least a second longitudinal region of the outer swirl chamber to be formed or delimited inwards, in particular directly, by the partition wall in the radial direction of the outer swirl chamber.In this case, it is particularly conceivable for the longitudinal regions of the swirl chambers to be arranged at the same height in the axial direction of the respective swirl chamber. During operation of the burner, only air, i.e. only the second part of the air, flows through the outer swirl chamber, while or wherein air, i.e. the first part, and the liquid fuel flow through the inner swirl chamber. Thus, advantageous mixing of the fuel with the first part of the air can already take place in the inner swirl chamber. The introduction element, in particular injection element, can be an injection nozzle whose outlet opening is arranged, for example, in or on an end face or end surface of the injection element, the end face or end surface of which extends in an end face or end surface plane running perpendicular to the axial direction of the respective swirl chamber.Furthermore, it is conceivable for the introduction element to be designed as a lance which has a longitudinal extension which, for example, coincides with the respective axial direction of the respective swirl chamber or the respective outflow opening. In this case, the lance has, for example, at least or exactly, in particular at least or exactly two, outlet openings which can be designed as bores, in particular transverse bores. The outlet opening has a passage direction along which the fuel can flow through the outlet opening. In particular when the introduction element is designed as an injection nozzle, the passage direction of the outlet opening runs parallel to the respective axial direction of the respective swirl chamber or the passage direction coincides with the respective axial direction of the respective swirl chamber or the respective outflow opening.In particular, when the introduction element is designed as a lance, the passage direction runs obliquely or preferably perpendicular to the axial direction of the respective swirl chamber or the respective outflow opening.

[0016] In particular, it is conceivable that at least the inner swirl chamber is formed by a component, in particular designed as a solid body, which also forms the atomizer lip and thus the end edge. In particular, an inner circumferential surface of the component delimits the inner swirl chamber to the outside in the radial direction of the inner swirl chamber. In this case, the component, in particular its inner circumferential surface, is or functions, for example, as a film layer between the swirl chambers and thus between the swirling and thus twisted flows, also referred to as air flows. In particular, it is conceivable that the inner circumferential surface or the film layer is formed by the aforementioned partition wall or that the component forms or has the aforementioned partition wall.In this case, the fuel flowing through the outlet opening and thus emerging from the introduction element, in particular being sprayed out, is applied, in particular as a film also referred to as a fuel film, to the film layer, in particular to the inner circumferential surface, or is atomized onto the film layer between the two swirling air flows by means of the introduction element. Due to centrifugal forces resulting from the swirling flow of the first part of the air, the fuel emerging from the introduction element, in particular being sprayed out, and thereby introduced, in particular injected, i.e. sprayed into the inner swirl chamber, in particular directly, is applied, in particular as the aforementioned film, to the film layer, in particular to the inner circumferential surface, and flows or streams downstream to the first outflow opening, also referred to as the nozzle opening, and thus to the end edge.As a result, the fuel is applied to the atomizer lip and conveyed or transported to the end edge. For example, the first outlet opening ends at the razor-sharp end edge, which, due to the previously described taper, has or provides only a small surface area, so that excessively large fuel droplets cannot form at the end edge. Due to the design of the atomizer lip and in particular of the end edge, only tiny fuel droplets break off at the end edge. In other words, only particularly small, i.e. tiny, droplets form from the aforementioned fuel film at the end edge, which break off at the end edge, in particular from the atomizer lip or from the component, and have a correspondingly large surface area. This effect leads to particularly low-soot combustion of the mixture in the combustion chamber.This makes it possible to produce tiny fuel droplets without the need for complex, high fuel injection pressures and cost-intensive injection elements, thus keeping burner costs particularly low. Furthermore, particularly small fuel droplets can be produced, allowing the burner to achieve very low outputs. The invention is based in particular on the findings that conventional burners have an excessively high pressure drop and are unsuitable for low outputs, thus resulting in disadvantageous fuel consumption. The aforementioned problems and disadvantages can now be avoided by the invention, thus keeping fuel consumption particularly low. When reference is made below to the injection element, the introduction element is to be understood as meaning the latter.

[0017] When reference is made below to the gas flowing through the exhaust tract, this can be understood to mean the aforementioned exhaust gas from the internal combustion engine or the aforementioned gas, unless stated otherwise. It is conceivable that the aforementioned inlet point, at which the burner exhaust gas can be introduced into the exhaust tract or into the gas, is arranged downstream or upstream of an oxidation catalyst of the exhaust tract, designed, for example, as a diesel oxidation catalyst, in the flow direction of the gas flowing through the exhaust tract. The oxidation catalyst is designed in particular to oxidize any unburned hydrocarbons (HC) contained in the exhaust gas and / or to oxidize any carbon monoxide (CO) contained in the exhaust gas, in particular to carbon dioxide.

[0018] In order to operate the burner particularly advantageously and thus heat and / or keep the component warm particularly quickly and efficiently, the first aspect of the invention provides that, in order to start the initially deactivated burner, the fuel is introduced, in particular injected, into the inner swirl chamber, in particular directly, during a first time period that is in particular predeterminable or predetermined, by means of the introduction element, in particular injection element. The feature that the first time period is, for example, predeterminable or predetermined, is to be understood in particular to mean that a duration of the first time period is predeterminable or predeterminable.The starting of the burner and the feature that the burner is initially deactivated is to be understood in particular as meaning that the burner is deactivated during a second period of time, in particular immediately or directly preceding the first period of time, in particular continuously, so that during the second period of time, in particular continuously, an introduction, in particular injection, of the fuel into the inner swirl chamber and an active supply of the swirl chambers with air as well as an ignition in the combustion chamber are omitted, i.e. do not take place.The feature that the second time period immediately or directly precedes the first time period is to be understood in particular as meaning that there is no other, further time period between the first time period and the second time period, so that the second time period preferably ends at the start of the first time period or, conversely, that the first time period begins at the end of the second time period. In particular, the first time period begins with the fuel being introduced, in particular injected, into the inner swirl chamber by means of the introduction element. In particular, it is provided that during the first time period the fuel is introduced, in particular injected, into the inner swirl chamber, in particular directly, by means of the introduction element.Furthermore, the invention provides that during the first period, an active supply of air to the swirl chamber is continuously avoided, so that ignition in the combustion chamber does not occur. Active supply of the swirl chambers means that the air is actively conveyed into the swirl chambers and thus into the burner by means of a conveying device, also referred to as an air pump or designed as an air pump, i.e., by actively operating the air pump, thus supplying the swirl chambers with air and thus with the air components. Such active supply of the swirl chambers with air and thus with the air components is avoided during the first period and preferably also during the second period.The feature that during the first time period and preferably also during the second time period, ignition or the ignition in the combustion chamber is omitted is to be understood in particular as meaning that no active ignition processes by means of which the mixture in the combustion chamber could be ignited if the mixture were present in the combustion chamber take place or are carried out, so that in particular during the first time period and also preferably during the second time period, for example, no ignition spark or other ignition event is carried out in the combustion chamber.

[0019] Furthermore, the invention provides that after the first time period, i.e. after the expiry of the first time period, the swirl chambers are actively supplied with air, in particular by means of the conveying device, the fuel is introduced, in particular injected, into the inner swirl chamber by means of the introduction element, and thus the mixture is generated in the combustion chamber and ignited, in particular actively, by means of an ignition device or the ignition device, for example in such a way that the ignition device generates or provides at least one ignition spark, in particular to a combustion chamber. In other words, the first time period is followed, in particular immediately or directly, by a third time period, which preferably lasts at least 10 seconds.Thus, it is preferably provided that the first time period ends with the start of the third time period or, conversely, that the third time period begins with the end of the first time period. In particular, the third time period begins when the swirl chamber is actively supplied with air, in particular with activation of the conveying device, which is initially deactivated, for example, and is deactivated, i.e., out of operation, for example, during the first time period and during the second time period, in particular continuously. Furthermore, the third time period begins, for example, when the ignition device, which is initially deactivated and is designed, for example, as a glow plug, glow pencil, or spark plug, is activated. For example, the ignition device is deactivated, in particular continuously, during the first time period and during the second time period.

[0020] During the third time period, the swirl chambers are actively supplied with air, in particular by the air being actively conveyed to and into the swirl chambers by means of the conveying device. For example, the conveying device is or can be operated electrically. In addition, during the third time period, the fuel is introduced, in particular injected, into the inner swirl chamber by means of the introduction element. It is conceivable that during the third time period, the fuel is introduced into the inner sub-chamber by means of the introduction element continuously, i.e. without interruption, or during or within the third time period, several chronologically successive and spaced-apart introductions, in particular injections, are carried out by means of the introduction element, in each of which the fuel is introduced, in particular directly, into the inner swirl chamber by means of the introduction element.By actively supplying the swirl chamber with air, the air and thus the parts flow through the swirl chambers. By actively supplying the swirl chamber with air and introducing, in particular injecting, the fuel into the inner swirl chamber, the mixture is formed, which is ignited and combusted during or within the third time period. This means, in particular, that during the third time period, the mixture is ignited or ignited in the combustion chamber, so that within or during the third time period, in particular without interruption, the mixture is combusted in the combustion chamber. Thus, it is provided that during the first time period and during the second time period, the burner does not produce a flame or burner exhaust gas.During the third period, however, the burner, in particular continuously or without interruption, provides the burner exhaust gas resulting from the ignition and combustion of the mixture or a flame resulting from the ignition and combustion of the mixture, whereby the component can be heated and / or kept warm. Because the fuel is introduced into the inner swirl chamber during the first period, but an active supply of air to the swirl chamber and ignition in the combustion chamber are omitted, a so-called pre-storage of the fuel in the inner swirl chamber is achieved or carried out. The invention is based in particular on the following findings and considerations: During a start-up, in particular designed as a cold start, of the initially deactivated burner, there is still neither a high temperature nor a high air movement in the respective swirl chamber.This condition prevents ignition of the mixture in the combustion chamber or at least makes such ignition difficult. The method according to the invention now makes it possible to start the initially deactivated burner quickly and effectively, particularly when the internal combustion engine is running and / or in cold ambient conditions. For this purpose, an ignitable mixture in the combustion chamber is advantageous, which can be achieved by pre-storing the fuel according to the invention.

[0021] It has proven particularly advantageous if the initial time period lasts at least 0.3 seconds. This allows an ignitable mixture to be created in the combustion chamber, allowing the burner to be started quickly and effectively.

[0022] In order to start the burner quickly, effectively, and efficiently, i.e., with low fuel consumption, a further embodiment of the invention provides for the first time period to last a maximum of 6 seconds, in particular a maximum of 4 seconds. In other words, it is preferably provided that the first time period lasts 0.3 to 6 seconds, in particular 0.3 to 4 seconds, in particular continuously or without interruption.

[0023] By pre-storing the fuel according to the invention, a particularly rich mixture is formed, in particular in the combustion chamber, whereby the particularly rich mixture offers a large fuel surface suitable for ignition despite large droplets and despite high dimensions.

[0024] In order to achieve particularly efficient operation of the burner, a further embodiment of the invention provides that at least after the time period, that is to say, for example, during the third time period, a first amount of air and a second amount of fuel are determined by means of an electronic computing device, also referred to as a control unit. In other words, after the time period, a first amount of air is determined by means of the electronic computing device, which is actively supplied to the swirl chambers within or during the third time period or after the first time period. In other words, again after the first time period, that is to say, for example, during the third time period, the first amount of air with which the swirl chambers are supplied, in particular actively, that is to say, for example, by operating the air pump, is determined by means of the electronic computing device.In addition, after the first time period, i.e. for example during the third time period, a second quantity of fuel is determined by means of the electronic computing device, which is introduced into the inner swirl chamber by means of the introduction element after the first time period, i.e. during and within the third time period. The first quantity is also referred to as the air quantity or air mass, and the second quantity is also referred to as the fuel quantity or fuel dimensions. For example, the air quantity is calculated, in particular by means of the electronic computing device, and thereby determined. Furthermore, it is conceivable that the air quantity is measured, in particular by means of a first sensor. For example, the first sensor provides at least one, in particular electrical, first signal which characterizes the air quantity measured by means of the first sensor.The electronic computing device can receive the first signal and thereby determine the particularly measured air quantity. Furthermore, it is conceivable that the fuel quantity is calculated and thereby determined, for example by means of the electronic computing device. Furthermore, it is conceivable, for example, that the fuel quantity is measured by means of a second sensor. The second sensor, for example, provides a second signal, in particular an electrical one, which characterizes the fuel quantity measured by the second sensor. The electronic computing device can, for example, receive the second signal and thereby determine the particularly measured fuel quantity.Furthermore, it is preferably provided that after the first time period, that is to say for example during the third time period, at least one actual value of a combustion air ratio of the mixture, also referred to as lambda (Greek lowercase letter lambda), is determined, in particular calculated, by means of the electronic computing device as a function of the first quantity and as a function of the second quantity. Furthermore, it is preferably provided that after the first time period and thus during the third time period, the burner is operated as a function of the determined actual value by means of the electronic computing device. Thus, lambda control, lambda-controlled operation of the burner is preferably provided, whereby particularly effective and efficient operation of the burner can be ensured.

[0025] It has proven particularly advantageous if the electronic computing device, particularly after the first time period and thus within or during the third time period, controls the feed element, particularly electrically, depending on the determined actual value and thereby operates the burner depending on the determined actual value. By controlling the feed element, the fuel quantity can, for example, be adjusted, particularly regulated, via the feed element by means of the electronic computing device, thereby enabling particularly effective and efficient operation of the burner.

[0026] A further embodiment is characterized in that the previously described air pump is provided, by means of which the air is to be actively conveyed to the swirl chambers and thereby actively to and into the burner, or is conveyed in particular during the third time period. Alternatively or additionally, a fuel pump is provided, by means of which the fuel is to be actively conveyed to and through the introduction element and thereby via the introduction element and thereby via the introduction element into the inner swirl chamber. In particular, it can be provided that the fuel pump is electrically operated or operated. In other words, the fuel pump is actively operated during the third time period, whereby the liquid fuel is actively conveyed to and in particular through the introduction element by means of the fuel pump, whereby the fuel is introduced into the inner swirl chamber via the introduction element.In this case, the fuel pump is electrically operated, for example, during the third period. With regard to the first period and the second period, it is therefore preferably provided that the air pump and the fuel pump are deactivated, i.e., out of operation, during the second period, so that no air is conveyed to the swirl chambers by means of the air pump during the second period. Furthermore, preferably, no fuel is conveyed to and through the introduction element by means of the fuel pump during the second period.For example, in order to pre-store the fuel during the first time period, thus introducing the fuel into the inner swirl chamber by means of the introduction element, the fuel pump is operated, in particular actively, during or within the first time period, so that, for example, the first time period begins with the initially deactivated fuel pump being activated, in particular while the air pump remains deactivated. Furthermore, it is conceivable that during the third time period both the fuel pump and the air pump are activated and thus operated, in particular electrically, so that, for example, the third time period begins with the initially deactivated air pump being activated, i.e., being put into operation.

[0027] In order to achieve particularly precise lambda control of the burner, a further embodiment of the invention provides for the use of a piston pump, in particular a frequency-controlled one, as the fuel pump. Using such a piston pump, in particular a frequency-controlled one, the fuel can be delivered or metered with particular precision, so that the fuel quantity and thus also the combustion air ratio can be determined, in particular calculated, with particular precision.

[0028] The piston pump has, for example, a pump housing through which the fuel can flow and a piston, also referred to as a delivery piston, which is at least partially, in particular at least predominantly or completely, accommodated in the pump housing. The piston is movable along a piston direction relative to the pump housing, in particular translationally, in order to thereby deliver the fuel. The piston pump, in particular the pump housing, has an outlet via which the fuel flowing through the pump housing and delivered by means of the piston can be discharged from the pump housing and thus conveyed away from the fuel pump and, for example, can be or is conveyed towards the introduction element. It is preferably provided that a spring-loaded valve is arranged at the outlet, which is designed or functions, for example, as a check valve.The valve thus comprises, for example, a valve body and, in particular, a mechanical spring. In particular, when the valve body is designed as a ball, the valve is designed as a ball valve. The valve body is movable, for example, relative to the pump housing, in particular translationally, between at least one closed position and at least one open position. In the closed position, the outlet is completely blocked by the valve body, and in the open position, the valve body releases it. It is preferably provided that the valve body or the valve opens in the direction of the introduction element, thus releasing the outlet, and blocks in the opposite direction, and thus, for example, in the direction of the piston or towards an interior of the pump housing, thus closing the outlet.This allows the piston to pump the fuel through the outlet and thus out of the pump housing and toward the introduction element. However, an opposing flow of fuel or another fluid, such as exhaust gas from the combustion chamber, can be prevented by the valve body or the valve itself, since the valve or the valve body blocks the outlet for a flow of fluid, such as exhaust gas from the combustion chamber, coming from the introduction element and into the pump housing. Thus, the valve prevents backflow of fuel or exhaust gas.

[0029] In order to achieve particularly effective and efficient operation of the burner, a further embodiment of the invention provides that the electronic computing device controls the air pump and / or the fuel pump as a function of the determined actual value, in particular electrically, and thus operates the air pump and / or the fuel pump as a function of the determined actual value, whereby the electronic computing device operates the burner as a function of the determined actual value. As a result, the combustion air ratio can be set particularly precisely and quickly, in particular to a desired target value, wherein the target value preferably lies in a range from 0.95 to 1.05 inclusive, and is preferably 1.03.

[0030] A further embodiment is characterized in that the actual value is compared with the in particular predefinable or predetermined target value by means of the electronic computing device, and the burner is operated depending on the comparison of the actual value with the target value. In this case, it is particularly conceivable for the electronic computing device to control and thereby operate the introduction element and / or the fuel pump and / or the air pump depending on the comparison and in particular depending on a difference between the target value and the actual value, in particular electrically, whereby the burner is operated, in particular regulated, depending on the comparison. In this way, particularly precise lambda control can be achieved.

[0031] In order to achieve particularly advantageous and, in particular, efficient and effective operation of the burner, a second aspect of the invention provides that a first quantity of air, also referred to as the air quantity, and a second quantity of fuel, also referred to as the fuel quantity, are determined by means of an electronic computing device, also referred to as a control unit. Depending on the first quantity and depending on the second quantity, at least one actual value of a combustion air ratio of the mixture is determined, in particular calculated, by means of the electronic computing device. Furthermore, the burner is operated by means of the electronic computing device depending on the determined actual value.This allows for particularly advantageous lambda control of the burner, allowing particularly efficient and effective, particularly fuel-efficient and low-emission, operation of the burner. Advantages and advantageous embodiments of the first aspect of the invention are to be regarded as advantages and advantageous embodiments of the second aspect of the invention, and vice versa.

[0032] Further advantages, features, and details of the invention will become apparent from the following description of preferred embodiments and from the drawings. 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 alone in the figures, can be used not only in the respective combinations specified, but also in other combinations or on their own, without departing from the scope of the invention.

[0033] The drawing shows: Fig. 1 is a schematic representation of a drive device of a motor vehicle, with an internal combustion engine, an exhaust tract and a burner according to the invention; Fig. 2 is a schematic longitudinal sectional view of a first embodiment of the burner; Fig. 3 is a detail of a schematic longitudinal sectional view of the burner according to the first embodiment; Fig. 4 is a schematic longitudinal sectional view of a component of the burner according to the first embodiment; Fig. 5 is a schematic longitudinal sectional view of a second embodiment of the burner; Fig. 6 is a detail of a schematic and perspective rear view of a third embodiment of the burner; Fig. 7 is a schematic longitudinal sectional view of the burner according to the third embodiment; Fig. 8 is a detail of a schematic and partially sectioned perspective view of a swirl generating device of the burner; Fig. 9 is a schematic perspective view of the swirl generating device;10 is a schematic front view of a closure device; Fig. 11 is a partial schematic longitudinal sectional view of a fourth embodiment of the burner; Fig. 12 is a partial schematic sectional view of a fifth embodiment of the burner; Fig. 13 is a partial schematic longitudinal sectional view of a sixth embodiment of the burner; Fig. 14 is a partial schematic longitudinal sectional view of a seventh embodiment of the burner; Fig. 15 is a schematic and partially sectioned side view of an injection element of the burner; Fig. 16 is a block diagram illustrating operation of the burner 42; Fig. 17 is a schematic sectional view of a fuel pump for conveying fuel to the burner; and Fig. 18 is a system diagram illustrating a method for operating the burner.

[0034] In the figures, identical or functionally identical elements are provided with the same reference numerals.

[0035] Fig. 1 shows a schematic representation of a drive device 10 of a motor vehicle, preferably designed as a motor vehicle, in particular as a passenger car. This means that the motor vehicle designed as a land vehicle, in its fully manufactured state, has the drive device 10 and can be driven by means of the drive device 10. The drive device 10 has an internal combustion engine 12, also referred to as an internal combustion engine, which has an engine block 14, also referred to as an engine housing. Furthermore, the internal combustion engine 12 has cylinders 16, which are formed or delimited by the engine block 14, in particular directly. During fired operation of the internal combustion engine 12, respective combustion processes take place in the cylinders 16, resulting in an exhaust gas from the internal combustion engine 12.For this purpose, within a respective working cycle of the internal combustion engine 12, a fuel, in particular a liquid fuel, is introduced into the respective cylinder 16, in particular injected directly. The internal combustion engine 12 can be designed as a diesel engine, so that the fuel is preferably a diesel fuel. A tank 18, also referred to as a fuel tank, is provided, in which the fuel can be received or is accommodated. Each cylinder 16 is assigned, for example, a respective injector, by means of which the fuel can be introduced into the respective cylinder 16, in particular directly injected. By means of a low-pressure pump 20, the fuel is pumped from the tank 18 to a high-pressure pump 22, by means of which the fuel is pumped 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 the 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 16, in particular inject it directly.

[0036] The drive device 10 comprises an intake tract 24 through which fresh air can flow, by means of which the fresh air flowing through the intake tract 24 is guided to and into the cylinders 16. The fresh air forms a fuel-air mixture with the fuel, which comprises the fresh air and the fuel and is ignited and thereby combusted in the respective cylinder 16 within the respective working cycle. In particular, the fuel-air mixture is ignited by auto-ignition. The ignition and combustion of the fuel-air mixture results in exhaust gas from the internal combustion engine 12, whose exhaust gas is also referred to as engine exhaust.

[0037] The drive device 10 has an exhaust tract 26 through which the exhaust gas from the cylinders 16 flows. The drive device 10 also includes an exhaust gas turbocharger 28, which has a compressor 30 arranged in the intake tract 24 and a turbine 32 arranged in the exhaust tract 26. The exhaust gas can flow out of the cylinders 16, flow into the exhaust tract 26, and then flow through the exhaust tract 26. The turbine 32 can be driven by the exhaust gas flowing through the exhaust tract 26. The compressor 30 can be driven by the turbine 32, in particular via a shaft 34 of the exhaust gas turbocharger 28. By driving the compressor 30, the fresh air flowing through the intake tract 24 is compressed by means of the compressor 30. In the exhaust tract 26, a plurality of components 36a-d are arranged, which are designed as respective exhaust gas aftertreatment devices, i.e. exhaust gas aftertreatment components for aftertreating the exhaust gas.In the flow direction of the exhaust gas of the internal combustion engine 12 flowing through the exhaust tract 26, the components 36a-d are arranged consecutively and are thus connected in series or in series with one another. Component 36a is, for example, an oxidation catalyst, in particular a diesel oxidation catalyst (DOC). Furthermore, component 36 can be a nitrogen oxide storage catalyst (NSC). Component 36b can be an SCR catalyst, which is also simply referred to as SCR. Component 36c can be a particulate filter, in particular a diesel particulate filter (DPF). Component 36d can, for example, have a second SCR catalyst and / or an ammonia slip catalyst (ASC).

[0038] 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. While the motor vehicle is traveling, people can be present in the interior. For example, the structure forms or delimits an engine compartment in which the internal combustion engine 12 is arranged. In this case, for example, the exhaust gas turbocharger 28 is also arranged in the engine compartment. The structure also has a floor, also referred to as the main floor, by which the interior is at least partially, in particular at least predominantly or completely, delimited downwards in the vertical direction of the vehicle. In this case, for example, the components 36a, b, c are arranged in the engine compartment, so that, for example, the components 36a, b, and c form a so-called hot end or are components of a so-called hot end.In particular, the hot end can be flanged directly to the turbine 32. Component 36d is arranged, for example, outside the engine compartment and below the floor in the vertical direction of the vehicle, so that component 36d forms a so-called cold end or is a component of the so-called cold end.

[0039] The drive device 10 comprises a metering device 38, by means of which a reducing agent, in particular a liquid one, can be introduced into the exhaust tract 26 at an inlet point E1, and thereby, for example, into the exhaust gas flowing through the exhaust tract 26. The reducing agent is preferably an aqueous urea solution, which can provide ammonia, which can react with any nitrogen oxides contained in the exhaust gas to form water and nitrogen during a selective catalytic reduction. The selective catalytic reduction can be catalytically effected and / or supported by the SCR catalyst. Fig. 1 It can be seen that in the flow direction of the exhaust gas flowing through the exhaust tract 26, the inlet point E1 is arranged upstream of the component 36b and downstream of the component 36a.

[0040] The exhaust gas tract 26 preferably has a mixing chamber 40 in which the reducing agent introduced into the exhaust gas at the inlet point E can advantageously be mixed with the exhaust gas.

[0041] The drive device 10 and thus the motor vehicle also comprise a burner 42, by means of which - as will be explained in more detail below - at least one of the components 36b, c, d arranged downstream of the burner 42 in the flow direction of the exhaust gas flowing through the exhaust tract 26 can be quickly and efficiently heated and / or kept warm. The burner 42 can combust a mixture, in particular by forming a flame 44 and in particular by providing a burner exhaust gas, wherein the burner exhaust gas or the flame 44 can be introduced or is introduced into the exhaust tract 26 at an inlet point E2. This means that the burner 42 is arranged at the inlet point E2. In the Fig. 1 In the embodiment shown, the inlet point E2 is arranged upstream of the components 36b, c and d and downstream of the component 36a. In other words, in the embodiment shown in Fig. 1 In the embodiment shown, the burner 42 is arranged upstream of the components 36b, c, d and downstream of the component 36a. Alternatively, it is conceivable that the burner 42 or the inlet point E2 is arranged upstream of the component 36a and in particular downstream of the turbine 32. The aforementioned mixture to be burned in the burner 42 or by means of the burner 42 comprises air and a liquid fuel. In the embodiment shown in Fig. 1 In the exemplary embodiment shown, the fuel is used as the fuel, and / or at least a portion of the air supplied to the burner 42 and used to form the mixture can originate, for example, from the intake tract 24. For this purpose, a fuel supply path 46 is provided, which is or can be fluidly connected to the burner 42 on the one hand and fluidly connected to a fuel line 48 on the other. The fuel flowing from the tank 18 to the injectors or to the fuel distribution element can flow through the fuel line 48. In particular, the fuel supply path 46 is fluidly connected to the fuel line 48 at a first connection point V2, wherein the connection point V2 is arranged downstream of the low-pressure pump 20 and upstream of the high-pressure pump 22 in the flow direction of the fuel flowing from the tank 18 to the fuel distribution element or to the respective injector.At the connection point V2, at least a portion of the liquid fuel flowing through the fuel line 48 can be branched off from the fuel line 48 and introduced into the fuel supply path 46. The fuel introduced into the fuel supply path 46 can flow through the fuel supply path 46 and is guided as the fuel by means of the fuel supply path 46 to, and in particular into, the burner 42. A first valve element 50 is arranged in the fuel supply path 46, by means of which a quantity of fuel flowing through the fuel supply path 46 and thus to be supplied to the burner 42 can be adjusted.In this case, an electronic computing device 52, also referred to as a control unit, is provided, by means of which the valve element 50 can be controlled, so that the amount of fuel flowing through the fuel supply path 46 and to be supplied to the burner 42 can be adjusted, in particular regulated, by means of the control unit via the valve element 50.

[0042] Furthermore, an air supply path 54 is provided, via or by means of which the burner can be or is supplied with the air for forming the mixture. This means that the air from which the mixture is formed can flow through the air supply path 54. A pump 56, also referred to as an air pump, is arranged in the air supply path 54, by means of which the air can be conveyed through the air supply path 54 and thus to the burner 42. For example, the low-pressure pump 20, also referred to 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 46 and thus to the burner 42.

[0043] It can be seen that the air supply path 54 is fluidically connected to the intake tract 24 at a second connection point V2. Thus, for example, at the connection point V2, at least a portion of the fresh air flowing through the intake tract 24 can be branched off from the intake tract 24 and introduced into the air supply path 54. The fresh air introduced into the air supply path 54 can flow through the air supply path 54 as the air and is guided by means of the air supply path 54 to and in particular into the burner 42. A second valve element 55 is arranged in the air supply path 54, by means of which valve element 55 the amount of air flowing through the air supply path 54 and thus through the burner 42, which is used to form the mixture, can be adjusted.In this case, for example, the control unit is designed to control the valve element 55 so that, for example, by means of the control unit via the valve element 55, the amount of air flowing through the air supply path 54 and thus to be supplied to the burner 42, which is used to form the mixture, can be adjusted, in particular regulated.

[0044] Fig. 2 shows a schematic sectional view of a first embodiment of the burner 42. The burner 42 has a combustion chamber 58 in which the mixture comprising the air supplied to the burner 42 and the liquid fuel supplied to the burner 42 is to be ignited and thereby burned, i.e., ignited and thereby burned during operation of the burner 42. For this purpose, an ignition device 60, designed, for example, as a spark plug or glow plug or glow pin, is provided, by means of which at least one ignition spark can be generated in the combustion chamber 58, in particular using electrical energy or electrical current. By means of the ignition spark, the mixture in the combustion chamber 58 is ignited and burned, in particular while providing the burner exhaust gas and / or while providing the flame 44.By means of the burner exhaust gas or by means of the flame 44, for example, the exhaust gas flowing through the exhaust tract 26 can be heated and / or kept warm quickly and efficiently, so that by means of the heated and / or kept warm exhaust gas flowing through the components 36b, c and d, for example, at least the component 36b can be heated and / or kept warm quickly and efficiently.

[0045] The burner 42 has an inner swirl chamber 62 through which a first portion of the air supplied to the burner 42 can flow and which causes a swirling first flow of the first portion of the air. This is to be understood in particular that the first portion of the air flows in a swirling manner through at least a first partial region of the swirl chamber 62 and / or flows out of the swirl chamber 62 in a swirling manner and / or flows in a swirling manner in the combustion chamber 58. The inner swirl chamber 62 has, in particular precisely, a first outflow opening 64 through which the first portion of the air can flow along a first passage direction of the outflow opening 64 and thus along a first flow direction coinciding with the first passage direction. The first portion of the air can be discharged from the inner swirl chamber 62 via the first outflow opening 64.This means that the first portion of the air can flow out of the inner swirl chamber 62 via the first outflow opening 64. Furthermore, the burner 42 comprises an introduction element in the form of an injection element 66, which has a channel 68 through which the liquid fuel supplied to the burner 42 can flow.

[0046] In the first embodiment, the injection element 66 is designed as a lance, which is also referred to as a fuel lance. The channel 68 and thus the injection element 66 has at least one outlet opening 70 through which the liquid fuel flowing through the channel 68 can flow. Fig. 2 It can be seen that in the first embodiment, the channel 68 and thus the injection element 66 has at least or exactly two outlet openings 70, for example designed as bores. The fuel can flow through the outlet opening 70 along a respective second passage direction, so that the fuel flowing through the injection element 66 can be sprayed out of the injection element 66 via the respective outlet opening 70 and can be injected, in particular directly, into the inner swirl chamber 62 and can thereby be introduced. In other words, the injection element 66 or the channel 68 opens into the inner swirl chamber 62 via the respective outlet opening 70, so that by means of the injection element 66, the liquid fuel can be injected via the respective outlet opening 70, in particular directly, into the inner swirl chamber 62.The respective second passage direction of the respective outlet opening 70 coincides with a respective second flow direction along which the fuel can flow through the respective outlet opening 70. It can be seen that the fuel can be sprayed out of the injection element 66 via the respective outlet opening 70 to form a respective fuel jet 72 and can thereby be injected, in particular directly, into the inner swirl chamber 62. For example, the respective fuel jet 72, whose longitudinal center axis coincides, for example, with the respective second passage direction or with the respective second flow direction, is at least substantially conical.In addition, for example, the injection element 66 and thus in the present case the channel 68 has a longitudinal direction or longitudinal extent or longitudinal extension direction which runs parallel to the first passage direction and thus parallel to the first flow direction, in particular coincides with the first passage direction and thus with the first flow direction. Furthermore, it is clear from . Fig. 2 It can be seen that the first passage direction and thus the first flow direction coincide with the axial direction of the outflow opening 64 and with the axial direction of the inner swirl chamber 62. The respective second passage direction or the respective second flow 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 swirl chamber 62 and the outflow opening 64.

[0047] The swirl chamber 62 is at least partially, in particular at least predominantly and thus more than half or completely, formed or delimited by a preferably integrally formed component 74 of the burner 42, so that the component 74 also forms or delimits the outflow opening 64.

[0048] The burner 42 further comprises an outer swirl chamber 76, which surrounds at least a longitudinal region and, in this case, also the first outflow opening 64 in the circumferential direction of the swirl chamber 62, in particular completely circumferentially. The component 74 comprises a partition wall 78, which is arranged between the swirl chambers 62 and 76 in the radial direction of the swirl chamber 62, the radial direction of which runs perpendicular to the axial direction of the swirl chamber 62. As a result, the swirl chambers 62 and 76 are separated from one another in the radial direction of the swirl chamber 65 by the partition wall 78. The axial direction of the swirl chamber 62 coincides with the axial direction of the swirl chamber 76, so that the radial direction of the swirl chamber 62 coincides with the radial direction of the swirl chamber 76.The outer swirl chamber 76 is capable of being flowed through by a second portion of the air supplied to the burner 42 and is configured to effect a swirling second flow of the second portion of the air. This means that the second portion of the air flows through the swirl chamber 76 in a swirling manner and / or flows out of the swirl chamber 76 in a swirling manner and / or flows in a swirling manner in the combustion chamber 58. In particular, it is preferably provided that the portions of the air exhibit their swirling flows in the combustion chamber 58, thus extending in a swirling manner in the combustion chamber 58.The outer swirl chamber 76 has, in particular precisely, a second outflow opening 80 through which the second part of the air flowing through the outer swirl chamber 76 can flow, in particular along a third flow direction, the third passage direction of which second outflow opening 80, along which the second part of the air flowing through the swirl chamber 76 can flow through the outflow opening 80, in this case coincides with the axial direction of the swirl chamber 76 and thus with the axial direction of the swirl chamber 62. The third passage direction coincides with a third flow direction along which the second part of the air flowing through the outer swirl chamber 76 flows or can flow through the outflow opening 80.This means, in particular, that the first passage direction coincides with the third passage direction and the first flow direction coincides with the second flow direction, so that in the present case the first flow direction, the third flow direction, the first passage direction and the third passage direction coincide with the axial direction of the swirl chamber 62 and with the axial direction of the swirl chamber 76. In the flow direction of the parts of the air, the second outflow opening 80 is arranged downstream of the outflow opening 64 and is arranged, in particular, in series with the outflow opening 64, so that the second part of the air, the first part of the air and the fuel can flow through the outflow opening 80. In particular, due to the swirling first flow, the first part of the air is already mixed with the fuel in the swirl chamber 62, in particular to form a partial mixture.The partial mixture can flow through the outflow opening 64 and thus flow out of the swirl chamber 62 and then flow through the outflow opening 80 and is mixed with the second part of the air, in particular due to the advantageous, swirl-shaped second flow, whereby the mixture is prepared in a particularly advantageous manner, and thus the partial mixture is mixed in a particularly advantageous manner with the second part.

[0049] It can be seen that the swirl chamber 76 is at least partially, in particular at least predominantly and thus at least more than half or completely, delimited inwardly in the radial direction of the respective swirl chamber 62 or 76 by the component 74, in particular by the partition wall 78. In the radial direction of the respective swirl chamber 62 or 76 outwardly, the swirl chamber 76 is at least partially, in particular at least predominantly or completely, delimited by a component 82, which in the present case is formed separately from the component 74. The component 74 is at least partially, in particular at least predominantly, arranged in the component 82.The outflow opening 80 is, for example, partially delimited or formed by the component 82 and partially by the component 74, in particular with regard to the smallest or smallest flow cross-section of the outflow opening 80 through which the second part of the air can flow.

[0050] In order to heat and / or keep warm at least the component 36b particularly efficiently, it is intended that - as can be seen particularly well from Fig. 3 can be seen - the first outflow opening 64 ends in the flow direction of the first part of the air flowing through the first outflow opening 64 and thus in the flow direction of the fuel flowing through the first outflow opening 64 at a specifically, in particular mechanically, machined and thus razor-sharp end edge K, which runs completely around the outflow opening 64, for example in the circumferential direction of the outflow opening 64 running around the axial direction of the outflow opening 64, the axial direction of which coincides with the axial direction of the respective swirl chamber 62 or 76. The razor-sharp end edge K is formed by an atomizer lip 84, which in the present case is formed by the component 74.The atomizer lip 84 tapers in the flow direction of the first portion of air flowing through the first outflow opening 64, and thus in the flow direction of the fuel flowing through the first outflow opening 64, up to the end edge K and ends at the end edge K. For example, the end edge K is ground and / or turned and is thus specifically mechanically machined. For example, the fuel is sprayed, in particular with the formation of the fuel jets 72, against the component 74, in particular against an inner circumferential surface 86 of the component 74, in particular in such a way that a fuel film, also simply referred to as a film, is formed from the fuel on the component 74, in particular on the inner circumferential surface 86. In this case, it can be seen in particular that the inner swirl chamber 62 is formed in the radial direction of the inner swirl chamber 62 outwards, in particular directly, by the inner circumferential surface 86.Due to the first swirling flow, in particular due to centrifugal forces resulting from the first swirling flow, the fuel film is transported along the inner circumferential surface 86 towards the end edge K, at which the fuel breaks away from the end edge K, whereby particularly tiny droplets of the fuel are formed from the fuel or from the fuel film. The component 74 is thus a so-called film layer or acts as a film bearing between the swirling flows. The droplets together form a particularly large surface area of ​​the fuel, so that particularly efficient operation of the burner can be achieved even with low burner power levels, whereby no costly pumps or costly high-pressure generation is required to generate the small and thus fine droplets of the fuel.The smallest flow cross section of the second outflow opening 80 through which the second partial fan can flow is completely limited or formed inwards by the end edge K in the radial direction of the respective outflow opening 64 or 80.

[0051] Furthermore, the burner 42 has an anti-recirculation plate 88, which in the first embodiment is arranged downstream of the outflow opening 80 and thus downstream of the component 82 in the flow direction of the parts flowing through the outflow opening 80 and the fuel flowing through the outflow opening 80. The anti-recirculation plate 88 has a flow-through opening 90, which is correspondingly arranged downstream of the outflow opening 80 and thus can be flowed through by the parts of the air and the fuel from the swirl chambers 62 and 76.Starting from the throughflow opening 90 and in particular starting from the outflow opening 80 and thereby starting from the component 82, in particular starting from its end, the anti-recirculation plate 88 extends outwardly in the axial direction of the respective swirl chamber 62 or 76, whereby the anti-recirculation plate 88 projects outwardly beyond at least a partial region T of the component 82 in the radial direction of the respective swirl chamber 62 or 76. As a result, for example, a first part T1 of the combustion chamber 58 is at least partially separated from a second part T2 of the combustion chamber 58 by means of the anti-recirculation plate 88.By means of the anti-recirculation plate 88, an excessive flow of the mixture flowing through the flow opening 90 and into the combustion chamber 58, in particular into the part T2, back in the direction of the component 82 or back into the part T1 can be avoided, so that an advantageous mixture preparation can be achieved.

[0052] Out of Fig. 2 It can also be seen that, for example, the swirl chambers 62 and 76 are supplied with the air or parts of the air via a supply chamber 92 common to the swirl chambers 62 and 76. The supply chamber 92 is arranged upstream of the swirl chambers 62 and 76 in the flow direction of the parts flowing through the swirl chambers 62 and 76. This means that the air is first introduced into the supply chamber 92 via the air supply path 54. The air that was introduced into the supply chamber 92 can flow through the supply chamber 92 on its way to and into the swirl chambers 62 and 76 and is divided, in particular by means of the component 74, into the first part and the second part.The air flowing through the air supply path 54 can, for example, flow out of the air supply path 54 and flow into the supply chamber 92 along a supply direction, wherein the supply direction runs, for example, obliquely and / or tangentially to the axial direction of the respective swirl chambers 62 and 76 and thus to their respective longitudinal axis.

[0053] Fig. 4 shows the component 74, also referred to as film layer, in a schematic longitudinal section. It can be seen that at least a part TB of the outer swirl chamber 76 is formed by the component 74. The component 74 has first swirl generators 94 of the inner swirl chamber 62 and second swirl generators 96 of the outer swirl chamber 76. The first swirl-shaped flow of the first part of the air is generated by means of the swirl generators 94, and the second swirl-shaped flow of the second part of the air is generated by means of the swirl generators 96. An inner annular surface, in particular of the inner swirl chamber 62, is in Fig. 4 designated K1, and an outer circular ring surface, in particular of the outer swirl chamber 76, is in Fig. 4 designated K2. The swirl generators 94 are arranged in an air duct LK1 of the swirl chamber 62, the air duct LK1 of which is delimited, in particular completely, by the component 74. In particular, the air duct LK1 is delimited outwards and inwards in the radial direction of the respective swirl chamber 62 or 76 by the component 74. The swirl generators 96 are arranged in a second air duct LK2 of the swirl chamber 76, the air duct LK2 of which is delimited completely and, in particular, outwards and inwards in the axial direction of the respective swirl chamber 62 or 76 by the component 74. For example, the swirl generators 94 and 96 are also formed by the component 74. The air duct LK1 can be flowed through by the first part of the air, and the air duct LK2 can be flowed through by the second part of the air, so that the swirl generators 94 generate or cause the first swirl-shaped flow and the swirl generators 96 generate or cause the second swirl-shaped flow.An outer diameter of the air duct LK1, also known as air guide, is denoted by Di, and an outer diameter of the air duct LK2, also known as air guide, is denoted by . Fig. 4 marked Da.

[0054] As from Fig. 2 bis 4 As can be seen, the outflow openings 64 and 80, also referred to as nozzles, are both aligned in the axial direction. This means that the partial mixture from the inner swirl chamber 62 flows into the combustion chamber 58 at least substantially in the axial direction. Furthermore, the second part of the air from the outer swirl chamber 76 also flows into the combustion chamber 58 at least substantially in the axial direction and, in doing so, entrains the finely distributed fuel from the film layer in small droplets into the combustion chamber 58 at the end edge K, in particular at its break-off point. The smallest or narrowest flow cross-section of the outer nozzle, i.e. the outflow opening 80, is located at the break-off point of the inner nozzle, i.e. the outflow opening 64, i.e. the end edge K.

[0055] It is preferably provided that the nozzles, thus the outflow openings 64 and 80, have the following size or area ratios: The outflow opening 64 (inner nozzle) preferably has a diameter, in particular an inner diameter, which is 10 percent to 20 percent of Di. Furthermore, it is preferably provided that the outer nozzle, thus the outflow opening 80, has a diameter, in particular an inner diameter, which is, for example, 10 percent to 35 percent of Da. An annular area from the inside to the outside should have the same area, i.e. both amount to 50 percent of the total annular area. In other words, it is preferably provided that the air duct LK1 has a first annular area and the air duct LK2 has a second annular area, wherein the annular areas are preferably the same size.

[0056] Fig. 5 shows a schematic sectional view of a second embodiment of the burner 42. In the first embodiment, for example, it is provided that the component 82 and the anti-recirculation plate 88 are designed as components that are formed separately from one another and at least indirectly, in particular directly, connected to one another. In the second embodiment, it is provided that the anti-recirculation plate 88 is formed integrally with the component 82. In the second embodiment, too, the anti-recirculation plate 88 can advantageously prevent the mixture from flowing backwards to the component 82 and forming a vortex after it exits the outer nozzle, thus from the outflow opening 80 and into the combustion chamber 58.Preferably, the anti-recirculation plate 88, also simply referred to as a plate, has a diameter, in particular an outer diameter, which is preferably at least as large as Di.

[0057] Fig. 6 shows a detail in a schematic perspective view of a third embodiment of the burner 42. In the third embodiment, the combustion chamber 58 has a plurality of through-flow openings 98, which are spaced apart from one another and separated from one another by respective wall regions W, in particular designed as respective solid bodies, in particular in the radial direction of the respective swirl chamber 62 or 76. The burner exhaust gas or the flame 44 can be discharged from the combustion chamber 58 via the through-flow openings 98 and introduced into the exhaust tract 26. In the present case, the wall regions W are formed integrally with one another and are formed, for example, by a one-piece perforated disk 100, which is designed as a solid body. In the present case, exactly eight through-flow openings 98 are provided. As in Fig. 2 As can be seen, it is fundamentally conceivable for the combustion chamber 58 to have precisely one large and undivided discharge opening 102, via which the burner exhaust gas or the flame 44 can be discharged from the combustion chamber 58 and introduced into the exhaust tract 26. In contrast, in the third embodiment, the plurality of spaced-apart and separate flow-through openings 98 are provided, so that the discharge opening 102 is, so to speak, divided or split by the wall regions W into the plurality of flow-through openings 98. It can be seen that the flow-through openings 98 are evenly distributed in the circumferential direction running around the axial direction of the respective swirl chamber 62 or 76 and are arranged in particular along a circle whose center point is arranged in the respective axial direction of the respective swirl chamber 62 or 76.Thus, in the third embodiment, instead of a large outlet opening in the form of the large discharge opening 102, a plurality of outlet openings in the form of flow-through openings 98 are provided, in particular at a particular location, in order to enable advantageous recirculation in the combustion chamber 58. Instead of a smaller outlet opening, it is advantageous to use a perforated plate such as the perforated disc 100 with a plurality of smaller openings in the form of the flow-through opening 98. The number of flow-through openings 98 is, for example, in a range from three to nine inclusive. The flow-through openings 98 have a similar or at least substantially identical flow-through area or outlet area through which the burner exhaust gas or the flame 44 can flow.The flow areas of the or all of the flow openings 98 add up to a total flow area, which is also referred to as the total outlet area and is, for example, 0.8 times to 1.8 times as large as that of a single, centrally arranged opening such as the discharge opening 102. For example, instead of a central outlet opening with a diameter of 25 millimeters and thus with a surface area of ​​491 square millimeters, it may be advantageous, depending on the flow conditions in the exhaust tract 26, to realize six smaller openings each with a diameter of 10.5 millimeters, so that a total outlet area of ​​520 square millimeters is shown.

[0058] Fig. 7 shows the third embodiment of the burner 42 in a schematic longitudinal section view, wherein the perforated disc 100, also referred to as a perforated plate, is provided. The aforementioned advantageous recirculation in the combustion chamber 58 is shown in Fig. 7 illustrated by an arrow 104. In addition, Fig. 7 a swirling flow of the mixture is illustrated and designated by 106, wherein the swirling flow 106 of the mixture in the combustion chamber 58 results from the respective swirling flows of the air components. The swirling flows of the air components and thus the swirling flow 106 of the mixture is realized in particular by the swirl generators 94 and 96 and by the tangential air supply, in particular via the air supply path 54. Preferably, the respective swirl generator 94 or 96 is designed as an air guide vane and not as a quarter-spherical sheet metal construction, so that the respective swirling flow can be generated or brought about particularly advantageously.The swirling flows of the air components and the resulting swirling flow 106 of the mixture in the combustion chamber 58 prevent the flame 44 from being blown out in the combustion chamber 58, optimizes the mixing of the air with the fuel in the combustion chamber 58, and creates a vortex burst to stabilize the flame 44. The recirculation in the combustion chamber 58, illustrated by the arrows 104, can be realized in particular by using the perforated plate and a resulting reduction in the outlet cross-section through which the flame 44 or the burner exhaust gas can be discharged from the combustion chamber 58 and introduced into the exhaust tract 26. The reduction in the outlet cross-section means, for example, that the total outlet area of ​​the individual flow openings 98 is smaller than the area of ​​the large, connected discharge openings 102.The advantageous recirculation in the combustion chamber 58, illustrated by the arrows 104, results in improved mixing of the air and fuel in the combustion chamber 58 and a longer residence time of the burning mixture in the combustion chamber 58, so that when the flame 44 or burner exhaust gas exits the combustion chamber 58 and into the exhaust tract 26, excessive emission of unburned hydrocarbons (HC) can be avoided, and a particularly high temperature of the flame 44 or burner exhaust gas can be achieved at its outlet. In particular, the recirculation leads to recirculation regions and vortex bursts, whereby a particularly long residence time of the flame 44 in the combustion chamber 58 can be achieved.

[0059] Fig. 8 shows a schematic and partially sectioned perspective view of a swirl generating device 107, which can be a component of the component 74 or formed by the component 74. The swirl generating device 107 comprises the swirl generators 94 of the inner swirl chamber 62 and the swirl generators 96 of the outer swirl chamber 76. Fig. 8 It can be seen that the swirl generators 96 and preferably also the swirl generators 94 are designed as air guide vanes, which can be designed, in particular shaped, to be aerodynamically favorable. This makes it possible to avoid excessive pressure loss, in particular in comparison to spherical swirl generators. The number of swirl generators 94 is, for example, in a range from six to eleven inclusive. Alternatively or additionally, the number of outer swirl generators 96 is, for example, in a range from eight to fourteen inclusive. The respective air duct LK1 or LK2, in which the swirl generators 94 or 96 are arranged, for example, has a respective surface area which is covered, for example, by at least 20 percent and at most 70 percent by the respective swirl generators arranged in the air duct LK1 or LK2.This provides a particularly advantageous axial blockage of at least 20 percent and at most 70 percent of the respective surface area. A respective radius of the respective air guide vane can extend from at least 40 percent of Di to infinity, so that the respective air guide vane can be straight. In particular, it is conceivable that the respective air guide vane encloses a respective angle α with the respective radial direction of the respective swirl chamber 62 and 76, which angle is, for example, in a range from 10 degrees up to and including 45 degrees. The aforementioned radius of the respective air guide vane, also simply referred to as a vane, is shown in . Fig. 8 designated by R. Preferably, the swirl generators 94 and 96 are designed to deflect the part of the air flowing through the respective air duct LK1 and LK2, respectively, and thus the air flowing through the respective air duct LK1 and LK2 and thus forming the respective part, by 70 degrees to 90 degrees, in particular with respect to the strictly or purely axial direction of the respective swirl chamber 62 and 76, respectively. In order to realize a particularly advantageous mixture preparation, the air guide vanes of the inner and outer swirl chambers 62 and 76 can be designed in opposite directions.In other words, it is conceivable that the outer swirl generators 96 of the outer swirl chamber 76 and the inner swirl generators 94 of the inner swirl chamber 62 are designed to form or cause the swirl-shaped flows of the parts of the air as counter-rotating or counter-directional swirl-shaped flows, so that, for example, the first flow is anti-clockwise and the second flow is clockwise or vice versa.

[0060] The swirl generating device 107 has a, in particular central, through-opening 108, through which the injection element 66 passes. In other words, the injection element 66 projects through the through-opening 108 into the inner swirl chamber 62.

[0061] Fig. 10 shows a schematic front view of a closure device 110, which in this case is designed as an iris diaphragm or in the manner of an iris diaphragm. If the burner 42 is not in operation, it may be advantageous to block an air line and a fuel line, that is, for example, the air supply path 54 and / or the fuel supply path 46 and / or the swirl chambers 62 and 76, and in this case, for example, the outflow opening 64 and / or the outflow opening 80, in order to prevent exhaust gas from the internal combustion engine 12 from penetrating the air supply path 54, the fuel supply path 46, the supply chamber 92, the swirl chamber 62 and / or the swirl chamber 76.Furthermore, it is conceivable to block the combustion chamber 58, or at least a longitudinal section of the combustion chamber 58, in order to prevent exhaust gas from the internal combustion engine 12 from penetrating the combustion chamber 58, or its partial section or longitudinal section, from entering it from the exhaust tract 26. For this purpose, the closure device 110 can be used, which can be arranged, for example, in the combustion chamber 58 or downstream of the combustion chamber 58. Closure elements 112 of the closure device 110, which can be moved in the manner of an iris diaphragm, can vary, i.e., variably adjust, an opening cross-section 114 through which, for example, the flame 44 or the burner exhaust gas can flow and which is delimited, in particular directly, by the closure elements 112. As a result, the opening cross-section 114 can be adjusted, in particular controlled or regulated, depending on the load.It is thus conceivable to close at least a portion of the combustion chamber 58 by means of the closure device 110. Alternatively or additionally, the outflow opening 80 can be closed, for example, by means of a first closure device 110. Alternatively or additionally, the outflow opening 80 can be closed, for example, by means of a second closure device 110. This has the particular advantage that an air and fuel supply can be closed simultaneously by means of a small plug. An air valve downstream of the pump 56 is then also not necessary, since it prevents exhaust gas from entering the pump 56. A much larger exhaust flap exposed to hot exhaust gas downstream of the combustion chamber 58 or downstream of its outlet can also be dispensed with.

[0062] In particular, it is conceivable that the opening cross-section 114 is an opening cross-section or outlet cross-section, in particular of the combustion chamber 58, wherein the flame 44 or the burner exhaust gas can be discharged from the combustion chamber 58 via the outlet cross-section and introduced into the exhaust tract 26. A tapering of the opening cross-section, which is necessary, required, or carried out to increase the flow velocity of the flame 44 or the burner exhaust gas from the combustion chamber 58, in particular by correspondingly moving the closure elements 112 in the manner of an iris diaphragm, should be realized in a streamlined manner. Thus, instead of a bore in a flat closure plate, a conical outlet with an angle of 30 degrees to 70 degrees to the horizontal could be provided, as is realized, for example, in an aircraft engine using segments and / or a cone.This can be achieved by a fixed geometry or also variable as in an aircraft engine with individual segments that are foldable, for example in a thrust nozzle, or with a displaceably arranged outlet cone, which is displaceable, for example, in the axial direction of the respective swirl chamber 62 or 76.

[0063] Fig. 11 shows a schematic sectional view of the burner 42 according to a fourth embodiment. Fig. 11 , but also from Fig. 2 and 7It can be seen that the combustion chamber 58 is formed or delimited by a chamber element 116, which is in particular designed as a solid body. In particular, the combustion chamber 58, the axial direction of which coincides with the axial direction of the respective swirl chamber 62 or 76, is delimited along its radial direction running parallel to the respective radial direction of the respective swirl chamber 62 or 76, in particular directly, by an inner circumferential surface 118 of the chamber element 116. The chamber element 116 can be formed in one piece. In the fourth embodiment, the chamber element 116 is designed such that it has two chamber parts 120 and 122, which are, for example, formed in one piece with one another, or the chamber parts 120 and 122 are components formed separately from one another and connected to one another. The inner circumferential surface 118 is formed by the chamber part 122.The chamber parts 120 and 122 are arranged one inside the other in such a way that at least one longitudinal region of the chamber part 120 surrounds at least one longitudinal region of the chamber part 122 in the circumferential direction of the combustion chamber 58 running around the axial direction of the combustion chamber 58, in particular completely circumferentially, wherein at least the longitudinal region of the chamber part 120 is spaced outwards in the radial direction of the combustion chamber 58 from the longitudinal region of the chamber part 122, in particular forming an intermediate space 124. The intermediate space 124 is arranged in the radial direction of the combustion chamber 58 between the chamber parts 120 and 122 and is designed, for example, as an air gap, in particular between the chamber parts 120 and 122. Furthermore, it can be seen that the essentially continuous or uninterrupted discharge opening 102 is formed or delimited completely circumferentially by the chamber part 122, in particular in the circumferential direction of the combustion chamber 58. In the case of the embodiment shown in . Fig. 2 In the first embodiment shown, the discharge opening 102 is not subdivided, that is to say, it is free of a component that divides the discharge opening 102 into several separate and spaced-apart flow openings. In the case of the Fig. 7 However, in the third embodiment shown, the perforated disc 100, also referred to as a perforated plate, is arranged in the discharge opening 102, by means of which perforated disc the essentially uninterrupted, i.e., connected discharge opening 102 is divided or split into the plurality of spaced-apart and separate flow-through openings 98 formed in the perforated disc 100. The flame 44 or the burner exhaust gas can flow out of the combustion chamber 58 along a fourth flow direction running in the axial direction of the combustion chamber 58, i.e., running parallel to the axial direction of the combustion chamber 58 or coinciding with the axial direction of the combustion chamber 58, and in doing so flow through the discharge opening 102 or through the respective flow-through opening 98, wherein the fourth flow direction coincides with the first, second, and third flow directions.It can be seen that the discharge opening 102 tapers in the flow direction of the burner exhaust gas flowing through the discharge opening 102, i.e., along the fourth flow direction. For this purpose, the chamber element 116, in particular the chamber part 120, has a longitudinal region L1 that tapers in the flow direction of the burner exhaust gas flowing through the discharge opening 102 and delimits the discharge opening 102 in the circumferential direction of the combustion chamber 58, in particular completely circumferentially. In other words, the longitudinal region L1 and thus the discharge opening 102 are conical, i.e., conical or frustoconical, in the flow direction of the burner exhaust gas flowing through the discharge opening 102.Since the burner exhaust gas or flame 44 flows out of the combustion chamber 58 via the discharge opening 102, the discharge opening 102 is formed at an outlet of the combustion chamber 58 or forms an outlet of the combustion chamber 58. In the fourth embodiment, the combustion chamber 58 is conical at its outlet, thus having a cone formed by the length range L1. Preferably, the discharge opening 102 has an inner diameter of 34 mm. In other words, it is preferably provided that the smallest or narrowest inner diameter of the discharge opening 102 through which the burner exhaust gas can flow is 43 mm.

[0064] Because at least the longitudinal regions of the chamber parts 120 and 122 are arranged one inside the other and are spaced apart from one another in the radial direction of the combustion chamber 58 to form the intermediate space 124, wherein the intermediate space 124 is filled with air, for example, and is thus designed as an air gap, a double-walled combustion chamber 58 or chamber element 116 is created, whereby the combustion chamber 58 is insulated by the intermediate space 124, i.e., by the air gap. Thus, the combustion chamber 58 is air-gap insulated. In the following, particular reference is made to the Fig. 4 shown outer diameter Da of the film applicator, in particular of the outer air duct LK2 of the outer swirl chamber 76, wherein the air duct LK2, in which the outer swirl generators 96 are arranged, and thus the outer diameter Da, in particular completely, are formed by the film applicator, that is to say by the component 74. With reference to Fig. 11 and the outer diameter Da, the combustion chamber 58 preferably has, in particular upstream of the cone or upstream of the length region L1, an inner diameter d1, which is preferably 1.0 times to 3.0 times Da. Furthermore, it is preferably provided that the smallest inner diameter d2 of the discharge opening 102, wherein the smallest inner diameter d2 of the discharge opening 102 is also referred to as the outlet diameter, is 0.7 times to 2.3 times Da. A smaller outlet diameter of the discharge opening 102 maintains the exit velocity of the burner exhaust gas and reduces the influence of the exhaust gas of the internal combustion engine 12, also referred to as the engine exhaust gas, on the flame 44, also referred to as the burner flame. A length l1 of the combustion chamber 58 running in the axial direction of the combustion chamber 58, in particular without secondary air injection, is preferably 1.5 times to 4.0 times Da.With secondary air injection, it is preferably provided that the length l1 of the combustion chamber is 2.0 times to 5.5 times Da.

[0065] Instead of the continuous discharge opening 102, it is conceivable to use the plurality of separate and spaced-apart flow openings 98. In other words, it is conceivable to divide the essentially continuous and thus uninterrupted discharge opening 102 into the plurality of spaced-apart and separate flow openings 98, the number of which preferably lies in a range from 3 to 9 inclusive. The respective flow opening 98 has a surface area, also referred to as an outlet area or flow area, wherein the sum of the surface areas of all flow openings 98 is preferably similar to the outlet area of ​​the connected discharge openings 102, i.e., similar to the surface area of ​​the discharge opening 102. The sum of the surface areas of the flow openings 98 is also referred to as the total outlet area. The flow openings 98 are designed, for example, as bores.It is conceivable that the sum of the surface areas of all flow openings 98, i.e., the total outlet area, is 0.8 times to 1.8 times the surface area of ​​the or an uninterrupted, connected discharge opening of the discharge opening 102 of the combustion chamber 58. In particular, it is conceivable that the perforated disk 100 is arranged in the discharge opening 102 or in the length region L1. With regard to the exhaust gas of the internal combustion engine 12, also referred to as engine exhaust gas, it may be advantageous to use a deflection element, in particular a deflection element and / or a perforated element, in particular a perforated plate, wherein the perforated element can be understood to be an element designed, in particular, as a solid body, which has a plurality of holes spaced apart from one another and separated, in particular, by respective walls, through which a gas, such as, for example, the burner exhaust gas or the engine exhaust gas, can flow.To ensure that, for example, the engine exhaust gas does not unduly negatively influence and destabilize the flame 44 in the combustion chamber 58, it is advantageous to provide a deflection element, such as a deflector plate, in front of the combustion chamber 58, i.e. upstream of the combustion chamber 58, so that the engine exhaust gas cannot enter the combustion chamber 58 or can only enter it to a small extent, in particular counter to the flow direction along which the flame 44 or the burner exhaust gas flows from the combustion chamber 58 into the exhaust tract 26. Thus, it is preferably provided that the deflection element is arranged in the exhaust tract 26 upstream of the combustion chamber 58, i.e. upstream of the inlet point E2, in the flow direction of the engine exhaust gas. The geometry of the deflection element can depend on how the combustion chamber 58 is arranged relative to the exhaust tract 26, i.e., relative to an exhaust duct of the exhaust tract 26.The exhaust gas duct is understood to mean that the burner exhaust gas or the flame 44 flows from the combustion chamber 58, in particular along the fourth flow direction, into the exhaust gas duct, in particular at the inlet point E2. Individual adaptation of the geometry of the deflection element is advantageous.

[0066] Furthermore, as previously described, it is advantageous that the closure device 110 or another closure device is arranged at the outlet of the combustion chamber 58. This particularly means the following: The closure device 110 can be arranged, for example, in the longitudinal region L1 or in the discharge opening 102, so that a flow cross-section through which the burner exhaust gas or the flame 44 can flow, and via which the burner exhaust gas or the flame 44 can be discharged from the combustion chamber 58, in particular at the inlet point E2, and introduced into the exhaust tract 26, in particular into the exhaust duct, is delimited by the closure device 110, in particular by the closure elements 112, and can therefore be varied, i.e., adjusted, by means of the closure device 110. This adjustable flow cross-section is, in particular, the opening cross-section 114.

[0067] The closure device 110 can be arranged in the chamber part 122 and in the discharge opening 102, or the closure device 110 or another closure device is arranged downstream of the combustion chamber 58, i.e. downstream of the chamber part 122 and directly adjacent to the combustion chamber 58 or the chamber part 122, and thus downstream of the discharge opening 102 itself. A tapering of the discharge opening 102, as is realized in the fourth embodiment by the length region L1, i.e. by the described cone, leads to an increase in the flow velocity of the burner exhaust gas, wherein the tapering of the outlet of the combustion chamber 58 should be presented in a streamlined manner. The cone formed here by the length region L1 preferably has an angle, also referred to as a cone angle, in particular to the Fig. 11 by a dashed line 126, of the axial direction of the combustion chamber 58 from 30° to 70°. In the fourth embodiment, the cone is designed as a fixed geometry, so that the cone, i.e. the cone angle, is fixed, i.e., cannot be varied. However, it is conceivable to design the cone, as in an aircraft engine, for example, to be variable, particularly with regard to its cone angle, in particular by means of individual segments which, for example, like a thrust nozzle in an aircraft engine, are foldable, i.e., in particular, can be pivoted relative to the chamber part 122, whereby the cone or the cone angle is adjustable, i.e., variable.Alternatively or additionally, it can be provided that the cone or its cone angle can be varied by a displaceably arranged outlet cone and / or that an outlet cone is provided whose longitudinal center axis coincides, for example, with the axial direction of the combustion chamber 58 and / or which is displaceable in the axial direction of the combustion chamber 58, in particular relative to the chamber element 116, wherein preferably the outlet cone, which is preferably arranged coaxially to the combustion chamber 58, tapers in the flow direction of the burner exhaust gas flowing through the discharge opening 102. The feature that the outlet cone is arranged coaxially to the combustion chamber 58 is to be understood in particular that the axial direction of the outlet cone, and thus its longitudinal center axis, coincides with the axial direction of the combustion chamber 58.By displacing the outlet cone in the axial direction of the combustion chamber 58 relative to the chamber element 116, the flow cross-section through which the burner exhaust gas can flow, and through which the burner exhaust gas can be discharged from the combustion chamber 58 and introduced into the exhaust gas duct, can be varied. The outlet cone is shown in . Fig. 11 shown particularly schematically and designated 128. A direction of movement running parallel to the axial direction of the combustion chamber 58 or coinciding with the axial direction of the combustion chamber 58, along which the outlet cone 128 is translationally movable, in particular displaceable, relative to the chamber element 116, is shown in Fig. 11 illustrated by a double arrow 130. It can be seen that the flow cross-section through which the burner exhaust gas can flow in the radial direction of the combustion chamber 58 is delimited, in particular directly, outwards by the chamber element 116 and inwards by the outlet cone 128, wherein the flow cross-section is annular or annular surface-shaped. Since the outlet cone 128 tapers in the flow direction of the burner exhaust gas flowing through the discharge opening 102 or the flow cross-section, the flow cross-section is varied by displacing the outlet cone 128 along the direction of movement and relative to the chamber element 116.

[0068] Fig. 12 shows a schematic sectional view of a fifth embodiment of the burner 42. In particular, Fig. 12 Partially the component 74 and partially the component 82 can be seen, in particular as in Fig. 3 . If the burner 42 is not operated, it is advantageous to close an air and fuel line, that is to say preferably the outlet openings 64 and 68, in order to prevent the engine exhaust gas from penetrating the swirl chambers 62 and 76.For this purpose, it is conceivable that, for example, a closure device 110 is arranged in each of the outflow opening 64 and / or in the outflow opening 80, or the closure device 110 is arranged downstream of the outflow opening 80 and directly adjoining the outflow opening 80, so that, for example, a first flow cross-section through which the first part of the air and the fuel can flow, in particular the outflow opening 64, and / or a second flow cross-section through which the parts of the air and the fuel can flow, in particular the outflow opening 80, or a third flow cross-section through which the parts of the air and the fuel can flow and is arranged downstream of the outflow opening 80 and directly adjoining the outflow opening 80 can be varied or adjusted by means of the closure device 110.The first, second, or third flow cross-section is, for example, the opening cross-section 114, that is, in particular, the opening cross-section 114 of an opening having the opening cross-section 114, the flow cross-section (opening cross-section 114) and thus the surface area of ​​which can be adjusted, in particular in the manner of an iris diaphragm, by means of the closure elements 112. Thus, the respective first, second, or third flow cross-section can be adjusted, in particular controlled or regulated, in particular in a load-dependent manner. For example, it is conceivable to close only the two outflow openings 64 and 80, also referred to as outlet nozzles, by means of the closure device 110 or by means of another, further closure device, thus reducing the first, second, or third flow cross-section to zero.

[0069] The additional locking device can, for example, be a Fig. 12 particularly schematically illustrated closure element designated 132, which is also referred to as a closure plug. The closure element 132 is movable, for example, particularly in the axial direction of the respective swirl chamber 62 or 76, relative to the component 82 and relative to the component 74, particularly translationally, particularly between at least one closed position and at least one in Fig. 12 shown open position. In the closed position, the outflow openings 64 and 80 are closed by the closure element 132 and thus fluidically blocked, in particular while the burner 42 is deactivated. As a result, no engine exhaust gas from the exhaust tract 26 can flow through the outflow openings 64 and 80. In the open position, the closure element 132 releases the outflow openings 64 and 80, in particular while the burner 42 is operating. It can be seen that the outflow openings 64 and 80 can be closed or are closed simultaneously by means of the closure element 132, which is designed, for example, as a small plug, in particular in the closed position of the closure element 132. Then, no air valve such as the valve element 55 downstream of the pump 56 is required, since the closure element 132 can be used to prevent engine exhaust gas from the exhaust tract 26 from flowing through the air supply path 54.In other words, the closure element 132 or the closure device 110 can prevent engine exhaust gas from entering the pump 56 from entering the exhaust tract 26. A much larger exhaust flap exposed to hot exhaust gas downstream of the combustion chamber 58, i.e., after its outlet, can also be dispensed with.

[0070] The previously mentioned air gap insulation of the combustion chamber 58 is explained in more detail below: Since the outer wall of the combustion chamber 58 becomes very hot, especially during full-load operation, and may even glow, the air gap insulation can ensure particularly safe operation. In addition, heat losses can be kept particularly low by the air gap insulation. In this case, it is preferably provided that insulation, in particular thermal insulation, completely surrounds the combustion chamber 58 in the circumferential direction running around the axial direction of the combustion chamber 58. In the present case, the air gap insulation, and thus the air gap, is provided as this insulation. The intermediate space 124, which is designed here as an air gap, preferably has a width, in particular a gap width, running in the radial direction of the combustion chamber 58, wherein the width, in particular a gap width, is preferably 6% to 25% of Da.In particular, it is conceivable for the width to be in a range from 1.5 mm to 6 mm inclusive. In particular, it can be seen that the chamber element 116 is a double-walled and therefore air-gap-insulated tube. In other words, the chamber parts 120 and 122 form a double-walled and therefore air-gap-insulated tube. In this case, it is preferably provided that an insulating element formed separately from the chamber element 116 (air-gap-insulated tube) surrounds the air-gap-insulated tube (chamber element 116), i.e., at least a longitudinal region of the chamber element 116 extending in the axial direction of the combustion chamber 58, in particular completely circumferentially in the circumferential direction of the combustion chamber 58. The insulating element is preferably an insulating mat. The insulating element is preferably formed at least from mineral wool and / or sheet metal, whereby the combustion chamber 58 can be particularly advantageously insulated.

[0071] A possible installation position of the combustion chamber 58 or the burner 42 is described below. As previously described, the mixture in the combustion chamber 58 is too thin to burn, releasing heat or thermal energy. Using the thermal energy, for example, at least the component 36b can be effectively and efficiently heated and / or kept warm. Alternatively or additionally, the component 36c, which is designed, for example, as a particulate filter, can be heated. By heating the particulate filter, for example, regeneration of the particulate filter can be effected or carried out. In order to be able to advantageously utilize the thermal energy of the burner 42, it or the introduction point E2 should be arranged as close as possible to the component to be heated or kept warm, such as the component 36b and / or 36c. This also makes it possible to keep heat losses to a minimum.However, to ensure advantageous mixing of the engine exhaust gas with the burner exhaust gas, a minimum distance should be provided for mixing the burner exhaust gas with the engine exhaust gas. This minimum distance extends, in particular in the flow direction of the engine exhaust gas flowing through the exhaust tract 26, from the burner 42 or from the inlet point E2, in particular continuously, to the component to be heated or kept warm, such as component 36b, in particular up to its inlet. In particular, the minimum distance is a minimum distance of the mixing chamber 40. Therefore, the inlet point E2 cannot be located directly near the inlet of component 36b.It has been shown to be particularly advantageous if a distance, particularly in the flow direction of the exhaust gas flowing through the exhaust tract 26, between the inlet point E2 and the component 36b, which particularly in the flow direction of the exhaust gas flowing through the exhaust tract 26 immediately following the inlet point E2, is at least 5 times to 8 times Da and at most 30 times Da. The feature that the component 36b is immediately or directly connected to the inlet point E2 in the flow direction of the exhaust gas (engine exhaust gas) flowing through the exhaust tract 26 is to be understood that no other, further exhaust gas aftertreatment component is arranged between the inlet point E2 and the component 36b in the flow direction of the exhaust gas flowing through the exhaust tract 26.Alternatively or additionally, a diameter, in particular an inner diameter, of the exhaust gas duct in which the inlet point E2 is arranged should widen conically to at least 6 times Da, in particular after exiting the combustion chamber 58, in particular before the exhaust gas enters the component 36b. In particular when the component 36b is a catalyst, in particular the aforementioned SCR catalyst, the component 36b has a substrate. Thus, it is preferably provided that the aforementioned distance is a distance running, in particular in the flow direction of the exhaust gas flowing through the exhaust tract 26, between the inlet point E2 and the substrate of the catalyst.It is therefore advantageous if the inner diameter of the exhaust gas channel expands to at least 6 times Da after exiting the combustion chamber 58, i.e., for example, starting from the inlet point E2, before the exhaust gas (engine exhaust gas or burner exhaust gas) hits the substrate.

[0072] Out of Fig. 2 It can be seen that the ignition device 60, which is designed, for example, as a spark plug, glow plug or glow pin, has a thread 134, which is designed in particular as an external thread, by means of which the ignition device 60 is at least indirectly screwed to the chamber element 116 and is thereby held on the chamber element 116. In order to achieve sufficient cooling of the ignition device 60, that is to say advantageous heat dissipation from the ignition device 60, it is advantageous if cooling fins are applied to the thread 134, also referred to as spark plug thread, of the ignition device 60. The number of cooling fins is preferably in a range from 1 to 7 inclusive. For example, the cooling fins have a thickness which is in a range from 2 to 4 mm inclusive. Furthermore, it is conceivable for the respective cooling fin to have a diameter of 20 to 80 mm, in particular an external diameter.In addition, it is advantageous if the individual cooling fins have openings, in particular through-openings, in particular designed as bores, in order to achieve advantageous heat dissipation to the environment of the ignition device 60, that is to say to the ambient air, the number of which is in a range from 3 to 8 inclusive. The respective through-opening of the respective cooling fin has, for example, a diameter, in particular an inner diameter, which is at least 5 mm and at most 15 mm. The electrode spacing between electrodes of the ignition device 60 is at least 0.7 mm and at most 10 mm. The electrodes are made of . Fig. 2 recognizable and designated there with 136 and 138, wherein by means of the electrodes 136 and 138, in particular between the electrodes 136 and 138, the ignition spark for igniting the mixture in the combustion chamber 58 is generated. In order to support the effecting or generating of the swirling flows of the parts of the air in the swirl chambers 62 and 76, the air should not be introduced strictly radially, i.e. in the radial direction of the respective swirl chambers 62 or 76, but tangentially or obliquely to the respective axial direction of the respective swirl chamber 62 or 76, as shown in Fig. 2 In other words, it is advantageous if the air or the respective portion of the air flows tangentially into the respective swirl chamber 62 or 76. This allows an impulse of the incoming air to be directed in the swirl direction, resulting in particularly high swirl generation efficiency.

[0073] In order to supply the burner 42 with fuel, a fuel pump, such as a fuel pump for conveying the fuel from the tank 18, is used. The fuel pump can thus be, for example, the low-pressure pump 20. It is advantageous to operate the burner 42 with lambda control, so that, for example, the mixture has a combustion air ratio (γ) of at least substantially 1.0. In other words, it is preferably provided that the burner is operated stoichiometrically, so that the mixture is a stoichiometric mixture. In other words, it is advantageous if a first proportion of air in the mixture and a second proportion of fuel in the mixture are adjusted or regulated as precisely as possible.It is therefore advantageous if a first quantity of the mixture's air, also referred to as combustion air, and a second quantity of the mixture's fuel are at least substantially precisely adjusted and / or calculated and introduced into the respective, corresponding swirl chambers 62 and 76, respectively. It is therefore advantageous to use a frequency-controlled piston pump as the fuel pump for conveying the fuel to or into the burner 42. This should be provided with a spring-loaded valve, such as a ball valve, at its outlet to prevent backflow of fuel or exhaust gas, particularly into the fuel pump.

[0074] Such a fuel pump is in Fig. 17 shown in a schematic longitudinal section and designated 137. The fuel pump 137 is designed as a piston pump, the piston for conveying the fuel is designated 138. The spring-loaded valve, which in the Fig. 17 shown embodiment is designed as a spring-loaded ball valve, is in Fig. 17 designated 140 and comprises a particularly mechanical spring unit 142 and a ball 144. In particular, the spring-loaded valve 140 is designed as a check valve or functions as a check valve, so that the fuel can be conveyed to the burner 42 by means of the fuel pump 137, so that the valve 140 opens in the direction of the burner, but closes in the opposite direction, so that no exhaust gas and no air can flow from the burner 42 back into the fuel pump 137.

[0075] Fig. 13 shows a schematic longitudinal sectional view of a sixth embodiment of the burner 42, in particular in Fig. 6 as well as in Fig. 12 the outflow openings 64 and 80 and thus the component 82 and the component 74 are visible. Also visible from Fig. 13 the injection element 66, which in the Fig. 13 However, the embodiment shown is Fig. 2 and 7is designed as a lance. The outlet openings are not arranged or formed on an axial end face 146 of the injection element 66 aligned in the axial direction of the swirl chambers 62 or 76, but the outlet openings 70 are aligned in the radial direction of the swirl chambers 62 or 76 and are formed in an outer circumferential surface 148 of the injection element 66, the outer circumferential surface 148 of which extends around the circumferential direction running in the axial direction of the respective swirl chamber 62 or 76. In other words, the respective fuel jet 72 does not exit the injection element 66 at the end face 146 and not in the axial direction or not parallel to the axial direction of the respective swirl chamber 62 or 76, but the fuel jet 72 exits perpendicularly or, in this case, obliquely to the Fig. 13 by a dashed line 150, axial direction of the respective swirl chamber 62 or 76 from the injection element 66.

[0076] The inner peripheral surface 86 of the component 74 is also referred to as a film wall, since the fuel, which is sprayed out of the injection element 66 via the outlet openings 70 and brought or sprayed against the film wall, forms the aforementioned film or fuel film on the film wall (inner peripheral surface 86). In order to particularly advantageously bring the fuel onto or against the film wall, a simple lance, such as the one shown in Fig. 13 The injection element 66 shown can be used. The lance comprises a tube 152, in the end region of which at least two outlet openings 70 are arranged, for example in the form of transverse bores. The fuel does not exit the lance or the tube 152 in the axial direction of the respective swirl chamber 62 or 76, but rather in a radial direction or obliquely to the radial direction of the respective swirl chamber 62 or 76. In order to be able to deliver the fuel exiting the outlet openings 70 particularly effectively onto the film layer and in particular onto or against the film wall, it is advantageous if the fuel is atomized.For this purpose, it is preferably provided if a Venturi nozzle 154 is arranged on or on the film wall, also referred to as film layer wall, which is arranged in particular in the axial direction of the respective swirl chamber 62 or 76, whose respective axial direction coincides with the axial direction and with the longitudinal extension direction of the injection element 66, in particular of the tube 152, at the level of the outlet openings 70, which are preferably arranged at the same height in the axial direction.In other words, the Venturi nozzle 154 is preferably provided in the swirl chamber 62, in which the outlet openings 70 are also arranged, the narrowest flow cross-section of which, through which the first portion of the air can flow, is preferably arranged in the axial direction of the respective swirl chamber 62 or 76 and thus of the injection element 66 such that the narrowest or smallest or smallest flow cross-section of the Venturi nozzle 154 and the respective outlet opening 70 are arranged at the same height in the axial direction of the respective swirl chamber 62 or 76 and thus in the axial direction of the injection element 66. This allows for particularly advantageous atomization of the fuel flowing through the outlet openings 70. In particular, the Venturi nozzle 154 and the injection element 66 can function like a jet pump.The first portion of the air flows through the Venturi nozzle 154, i.e., through its narrowest flow cross-section. Since the outlet openings 70 are each arranged at least partially in the narrowest flow cross-section of the Venturi nozzle 154, i.e., since the narrowest flow cross-section of the Venturi nozzle 154 and the outlet openings 70 are arranged at the same height in the axial direction of the injection element 66 and thus the flow direction of the first portion of air flowing through the Venturi nozzle 154, the first portion of the air acts or functions as a propellant medium that, so to speak, sucks in the fuel as a suction medium, in particular via the outlet openings 70, so that the propellant medium, so to speak, sucks the suction medium (fuel) through the outlet openings 70. As a result, the fuel is particularly advantageously atomized in the swirl chamber 62.

[0077] Fig. 14 shows a detail of a seventh embodiment of the burner in a schematic longitudinal sectional view. In the seventh embodiment, the injection element 66 is designed, for example, as a lance. It can be seen that the respective fuel jet 72, in particular its longitudinal axis or longitudinal center axis, encloses an angle β, also referred to as the jet angle, with an imaginary plane EB running perpendicular to the axial direction of the respective swirl chamber 62 or 76 and thus perpendicular to the respective flow direction of the respective part of the air flowing through the respective swirl chamber 62 or 76. The axial direction of the respective swirl chamber 62 or 76 coincides with the longitudinal extension direction or longitudinal extension of the injection element 66 and thus with its axial direction.The outlet openings 70 are arranged in a circumferential direction extending around the axial direction of the injection element 66, in particular uniformly, distributed and spaced apart from one another. In order to produce the thinnest and most uniform fuel film possible on the film layer, i.e., on the inner circumferential surface 86, the number of outlet openings 70 is preferably at least 2 and at most 10. In other words, it is provided, for example, that the number of outlet openings 70 lies in a range from 2 to 10 inclusive. For example, it is preferably provided that the angle β lies in a range from 10° to 60° inclusive, in particular in order to direct a pulse of the fuel in the direction of flow.Furthermore, it is provided that the respective, preferably circular outlet opening 70, which is designed, for example, as a bore, has a diameter, in particular an inner diameter, which lies in a range from 50 mm to 3 mm inclusive.

[0078] Fig. 15 shows a schematic and partially sectioned side view of a possible further embodiment of the injection element 66. In the Fig. 15 In the embodiment shown, the injection element 66 is designed as an injection nozzle as used in heating oil burners. Fig. 15 In the embodiment shown, the injection element 66 has a head 155, a swirl slot 156, a swirl body 158, a secondary filter 160 and a primary filter 162. The injection element 66 according to Fig. 15 has at least or exactly one outlet opening 70, wherein the outlet opening 70 of the injection element 66 is arranged or formed on its axial end face 146, which is also referred to as the axial end face. This means that the fuel jet 72 flowing through the outlet opening 70 exits the outlet opening 70 and thus the injection element 66 in the axial direction of the injection element 66 and thus of the respective swirl chamber 62 or 76. In other words, according to Fig. 15 the fuel jet 72 or its longitudinal axis or longitudinal center axis at least substantially in the axial direction, that is to say parallel to the axial direction of the respective swirl chamber 62 or 76.

[0079] Fig. 16 shows a block diagram illustrating operation, in particular control, of the burner 42. A temperature of the exhaust gas at the inlet point E2 or downstream of the inlet point E2 and in particular upstream of the component 36b is designated T5. For example, the temperature T5 is measured, in particular by means of a temperature sensor, so that, for example, a value, also referred to as the T5 value, which characterizes the temperature T5, is measured. The T5 value is in Fig. 16 illustrated by a block 164. The T5 value is transmitted, in particular as an input variable, to a block 166. Block 166 illustrates an initial state in which, for example, an air supply in the burner 42 is closed, the fuel pump is deactivated, so that a fuel supply in the burner 42 is also deactivated, and the ignition device 60 is deactivated. An arrow 168 illustrates a so-called burner enable, i.e., an enable of the burner. As a result of the burner enable, the ignition device 60 is switched on, i.e., activated, in a block 170. In a block 172, for example, a combustion air ratio of the mixture of 0.9 is set in order to thus realize a starting operation of the burner 42. In addition, for example, in block 172, the air pump is activated, and the fuel pump is activated.Subsequently, in a block 174, for example, the combustion air ratio of the mixture is set to 1.03, with the fuel pump being operated at a low frequency. In a block 176, for example, the ignition device 60 is deactivated. A block 178 illustrates an operating state of the burner 42. In the operating state, an air supply to or in the burner 42 is open, the fuel pump is switched on, and the ignition device 60 is deactivated, so that the burner 42 is supplied with air and fuel. An arrow 180 illustrates that the burner enable is revoked, in particular when the temperature T5 is greater than a limit value, which is, for example, 400°C.

[0080] In a block 182, a comparison is made in which an actual value of the temperature T5 is compared with a target value of the temperature T5. The actual value of the temperature T5 is, for example, the aforementioned T5 value and / or, for example, the actual value of the temperature T5 is measured, in particular by means of the aforementioned temperature sensor, in particular at the inlet point E2 or at a point in the exhaust tract 26 arranged downstream of the inlet point E2 and in particular upstream of the component 36b. If, for example, the comparison shows that the actual value is less than or equal to the target value, a state set in particular in block 174 is maintained, in particular with regard to the operation of the fuel pump and the air pump, wherein the fuel pump in Fig. 16 by a block 184 and the air pump by a block 186. If, for example, the actual value is greater than the target value, the fuel pump is controlled in block 188, in particular by means of an electronic computing device also referred to as a control unit, and / or the air pump is controlled in block 190, in particular by the control unit, in particular to the effect that the fuel pump or the air pump is changed with regard to its respective operation, in particular such that the actual value is reduced until, for example, the actual value corresponds to the target value or is less than the target value.

[0081] In a block 192, the amount of air in the mixture is determined, in particular measured, in particular by measuring the air flow. An arrow 194 also illustrates that the amount of fuel is determined, in particular measured. In a block 196, the combustion air ratio (γ) is determined, in particular calculated, as a function of the determined, in particular measured, amount of air and as a function of the determined, in particular measured or calculated, amount of fuel. In particular, in block 196, an actual value of the combustion air ratio of the mixture is determined, in particular calculated. In a block 198, the actual value of the combustion air ratio is compared with a second target value of the combustion air ratio, the second target value being, for example, 1.03.If the actual value of the combustion air ratio corresponds to the target value of the combustion air ratio, or if the actual value of the combustion air ratio deviates from the target value of the combustion air ratio only to such an extent that a difference between the actual value of the combustion air ratio and the target value of the combustion air ratio is, in particular, greater than or equal to a limit in terms of amount, then current operation of the burner 42, in particular of the fuel pump and the air pump, is maintained.However, if the actual value of the combustion air ratio deviates excessively from the target value of the combustion air ratio, then, as particularly indicated by an arrow 200, the air pump and / or the fuel pump, for example, are modified with regard to their respective operation, particularly by controlling the fuel pump or air pump, particularly such that the difference between the actual value of the combustion air ratio and the target value of the combustion air ratio is at least reduced or eliminated. Finally, a block 202 illustrates that the target value of the temperature T5 is specified from or by the control unit, particularly to block 182. Alternatively or additionally, the control unit can specify or output the target value of the combustion air ratio, particularly to block 198.

[0082] It can be seen that the low-pressure pump 20 is used as a fuel pump, by means of which, in particular actively, the fuel is conveyed to and in particular through the injection element 66, in order to thereby inject the fuel, in particular directly, into the inner swirl chamber 62 via the injection element 66. The low-pressure pump 20 has a dual function in that it is used, for example, on the one hand to convey the fuel as the fuel to the injection element 66 and, on the other hand, to convey the fuel from the tank 18 to the high-pressure pump 22.Alternatively, it would be conceivable to use a fuel pump specifically provided for the burner 42, i.e., a fuel pump by means of which, in particular actively, the fuel, in particular as the fuel from the tank 18, can be or is conveyed to the burner 42, although this dedicated fuel pump cannot convey fuel from the tank 18 to the high-pressure pump 22. Thus, the fuel pump 137, designed, for example, as a piston pump, can be used, by means of which the fuel can also be conveyed, in particular, through the injection element 66.

[0083] Fig. 18 shows a system diagram for illustrating the burner 42 and in particular for illustrating a method for operating the burner 42. Arrows 204 in Fig. 18 illustrates that the electronic computing device 52 can control the air pump 56, the injection element 66 and the ignition device 60, in particular electrically. Alternatively or additionally, the electronic computing device 52 can control the fuel pump, in particular electrically. An arrow 206 illustrates the aforementioned air line, thus the air supply path 54. In other words, the air supply path 54 is or comprises at least one air line, by means of which the air can be introduced into the respective swirl chamber 62 or 76 or into the air chamber 92, in particular tangentially or obliquely to the axial direction of the respective swirl chamber 62 or 76. In addition, an arrow 208 illustrates a or the aforementioned fuel line, also referred to as a fuel line, via which the injection element 66 can be supplied with the fuel.Thus, the arrow 208 particularly illustrates the fuel supply path 46 and / or the channel 68.

[0084] By controlling the injection element 66, for example, it is to be understood that a valve element of the injection element 66 is or becomes adjustable between at least one closed position and at least one open position by controlling the injection element 66. In the closed position, the valve element blocks, for example, the outlet openings 70, and in the open position, the valve element releases, for example, the outlet openings 70. Alternatively or additionally, controlling the injection element 66 can be understood as the previously described control of the fuel pump, such as the piston pump 136, which can be operated electrically in particular.

[0085] In order to achieve particularly efficient and effective operation of the burner 42, as already mentioned with regard to Fig. 16was indicated - by means of the electronic computing device 52 (control unit) a first quantity of air, also referred to as the air quantity, which is supplied to the swirl chambers 62 and 76, in particular actively, or with which the swirl chambers 62 and 76 are, in particular actively, supplied, is determined. The active supply of air to or into the swirl chambers 62 and 76 is to be understood that the air is actively conveyed by means of the air pump 56, in particular by electrically operating the air pump 56, and is thereby conveyed to and into the swirl chambers 62 and 76. In addition, by means of the electronic computing device 52 a second quantity of fuel, also referred to as the fuel quantity, is determined, which is supplied to the injection element 66, in particular actively, or with which the injection element 66 is, in particular actively, supplied.The active supply of fuel to the injection element 66 is to be understood in particular as meaning that the fuel is conveyed by means of the fuel pump, in particular by electrically operating the fuel pump, and is thereby also conveyed by the injection element 66 and in particular is injected via the injection element 66 into the inner swirl chamber 62.

[0086] Depending on the air quantity and the fuel quantity, at least one actual value of the combustion air ratio is determined, in particular calculated, by means of the electronic computing device 52. Furthermore, the burner 42 is operated by means of the electronic computing device 72 in accordance with the determined actual value, in particular such that the electronic computing device 52 controls the air pump 56 and / or the injection element 66 and / or the fuel pump and / or the ignition device 60, in particular electrically and / or in accordance with the determined actual value. This is done in particular by comparing the actual value with the target value, in particular by means of the electronic computing device 52.The electronic computing device 52 operates the burner 42 depending on the comparison of the actual value with the desired value of the combustion power ratio, whereby a particularly advantageous lambda control of the burner 42 can be represented.

[0087] Alternatively or additionally, it can be provided that, in order to start the initially deactivated burner 42, the fuel is injected, in particular directly, into the inner swirl chamber 62 during a first period of time by means of the injection element 66, wherein during the first period of time, the swirl chambers 62 and 76 are continuously actively supplied with air, i.e., with the lines of air, and ignition in the combustion chamber 58 is omitted. After the first period of time, i.e., for example, during a second period of time immediately following or directly following the first period of time, the swirl chambers 62 and 76 are actively supplied with air, the fuel is injected into the inner swirl chamber 62 during or within the second period of time by means of the injection element 66, and during or within the second period of time, the mixture is ignited and combusted in the combustion chamber 58.This allows the initially deactivated burner 42 to be started particularly quickly and efficiently, particularly during a cold start and / or in cold ambient conditions.

Claims

1. Method for operating a burner (42) of a motor vehicle which has an exhaust tract (26) through which exhaust gas from an internal combustion engine (12) can flow, wherein the burner (42) comprises: - a combustion chamber (58), in which a mixture comprising air and a liquid fuel is to be ignited and thereby combusted, - an inner swirl chamber (62), through which a first portion of the air can flow and which causes a swirl-like flow of the first portion of the air, which inner swirl chamber comprises a first outflow opening (64), through which the first portion of the air flowing through the inner swirl chamber (62) can flow, via which first outflow opening the first portion of the air can be discharged from the inner swirl chamber (62), - an introduction element (66), which has at least one outlet opening (70) through which the liquid fuel can flow and which is arranged in the inner swirl chamber (62), by means of which introduction element the fuel can be introduced into the inner swirl chamber (62) via the outlet opening (70), through the first outflow opening (64) of which swirl chamber the fuel which exited the introduction element (66) via the outlet opening (70) and was thereby introduced into the inner swirl chamber (62) can also flow, and - an outer swirl chamber (76), which surrounds at least a length region of the inner swirl chamber (62) in the circumferential direction of the inner swirl chamber (62) and through which a second portion of the air can flow and which causes a swirling flow of the second portion of the air, which outer swirl chamber has a second outflow opening (80), through which the second portion of the air flowing through the outer swirl chamber (76), the fuel flowing through the first outflow opening (64), and the first portion of the air flowing through the inner swirl chamber (62) and the first outflow opening (64) can flow, via which second outflow opening the portions of the air and the fuel can be introduced into the combustion chamber (58), wherein in order to start the burner (42): ∘ during a period of time, the fuel is introduced into the inner swirl chamber (62) by means of the introduction element (66), ∘ during the period of time, active supply of the air to the swirl chambers and ignition in the combustion chamber are completely stopped, and ∘ after the period of time, the swirl chambers are actively supplied with air, the fuel is introduced into the inner swirl chamber by means of the introduction element, and the mixture is ignited and combusted in the combustion chamber.

2. Method according to claim 1, characterized in that the period of time lasts at least 0.3 seconds.

3. Method according to claim 1 or claim 2, characterized in that the period of time lasts no more than 6 seconds, in particular no more than 4 seconds.

4. Method according to any of the preceding claims, characterized in that at least after the period of time, by means of an electronic computing device (52): - a first quantity of air and a second quantity of fuel are determined, - at least one actual value of a combustion air ratio of the mixture is determined on the basis of the first quantity and the second quantity, and - the burner (42) is operated on the basis of the determined actual value.

5. Method according to claim 4, characterized in that the electronic computing device (52) controls the introduction element (66) on the basis of the determined actual value and thereby operates the burner (42) on the basis of the determined actual value.

6. Method according to any of the preceding claims, characterized by: - an air pump (56), by means of which the air is to be actively conveyed to the swirl chambers (62, 76) and thereby actively to and into the burner (42), and / or - a fuel pump (136), by means of which the fuel is to be actively conveyed to and through the introduction element (66) and thereby via the introduction element (66) into the inner swirl chambers (62).

7. Method according to claim 6, characterized in that a piston pump (136) is used as the fuel pump (136).

8. Method according to claim 7 in its back reference to claim 5 or 4 via claim 6, or according to claim 6 in its back reference to claim 5 or 4, characterized in that the electronic computing device (52) controls the air pump (56) and / or the fuel pump (136) on the basis of the determined actual value and thereby operates the burner (42) on the basis of the determined actual value.

9. Method according to claim 8, according to claim 7 in its back reference to claim 4 or 5 via claim 6, according to claim 6 in its back reference to claim 4 or 5, according to claim 5, or according to claim 4, characterized in that the actual value is compared with a target value by means of the electronic computing device (52) and the burner (42) is operated on the basis of the comparison.