Burner for an exhaust tract through which exhaust gas from an internal combustion engine flows, internal combustion engine and process

Abstract

The invention relates to a burner (10) for an exhaust tract through which exhaust gas of an internal combustion engine of a motor vehicle flows, with an ignition device (16) and with a combustion chamber (12) in which a mixture comprising air and fuel is to be ignited and thereby burned by means of the ignition device (16), wherein at least one heating element (50) designed separately from the ignition device (16) is provided, by means of which the ignition device (16) can be heated.

Description

[0001] The invention relates to a burner for an exhaust tract through which exhaust gas from an internal combustion engine of a motor vehicle flows, according to the preamble of claim 1. Furthermore, the invention relates to an internal combustion engine for a motor vehicle with such a burner and to a method for operating such a burner.

[0002] DE 10 2021 001 580 A1 discloses a burner for an exhaust tract through which exhaust gas of an internal combustion engine of a motor vehicle flows, with a combustion chamber in which a mixture comprising air and a liquid fuel is to be ignited and thereby burned.

[0003] The object of the present invention is to provide a burner for an exhaust tract through which exhaust gas from an internal combustion engine of a motor vehicle flows, an internal combustion engine with such a burner and a method for operating such a burner, so that a mixture comprising air and a liquid fuel can be ignited particularly well.

[0004] This problem is solved according to the invention by a burner for an exhaust tract through which exhaust gas from an internal combustion engine of a motor vehicle flows, comprising the features of claim 1, by an internal combustion engine for a motor vehicle comprising the features of claim 9, and by a method for operating a burner for an exhaust tract through which exhaust gas from an internal combustion engine of a motor vehicle flows, comprising the features of claim 10. Advantageous embodiments with expedient further developments of the invention are specified in the remaining claims.

[0005] A first aspect of the invention relates to a burner for an exhaust tract through which exhaust gas from an internal combustion engine of a motor vehicle flows or through which exhaust gas flows. The motor vehicle is, for example, a car, in particular a passenger car or commercial vehicle. Preferably, the internal combustion engine, particularly in its fully manufactured state, includes the burner. Preferably, the burner can be arranged or is arranged in the exhaust tract of the internal combustion engine.

[0006] The internal combustion engine preferably has at least one combustion chamber in which combustion processes take place, during which a fuel-air mixture is to be burned or is burned. The combustion chamber is, for example, designed as a cylinder. The combustion chamber is separate from the burner. In particular, the combustion chamber and the burner are spaced apart from each other. The internal combustion engine preferably has at least one intake manifold through which air can flow into the combustion chamber. This means that the air flowing through the intake manifold can be introduced into, or is introduced into, the combustion chamber of the internal combustion engine. The exhaust gas produced from the combustion of the fuel-air mixture in the combustion chamber can be discharged from the combustion chamber via the exhaust manifold. Thus, the exhaust gas can be discharged from the combustion chamber and introduced into the exhaust system.

[0007] The burner has at least one ignition device and at least one combustion chamber in which a mixture of air and fuel is ignited by the ignition device and thereby combusted. In other words, combustion processes take place in the combustion chamber in which the mixture of air and fuel is burned, and these combustion processes can be initiated by the ignition device, that is, by ignition by the ignition device, for example, by at least one spark provided by the ignition device. Initiation can be understood in particular as the starting of the combustion processes, that is, the combustion in the combustion chamber.However, the combustion processes taking place in the burner's combustion chamber and those taking place in the combustion chamber of the internal combustion engine are distinct processes, occurring in different locations. For example, the fuel used is a liquid. The ignition system, for instance, is located at least partially within the combustion chamber.

[0008] The burner preferably has at least one housing element, which can be referred to in particular as a combustion chamber housing or burner housing. The housing element delimits the combustion chamber at least partially, in particular predominantly or completely, for example in the radial direction of the combustion chamber and / or in the axial direction of the combustion chamber.

[0009] Preferably, the burner has at least one outlet element, which in particular at least partially delimits the combustion chamber, for example in the axial direction of the combustion chamber. This outlet element has at least one burner outlet opening through which burner exhaust gas generated by the combustion of the mixture can be discharged from the combustion chamber to heat the exhaust tract of the internal combustion engine, in particular to heat at least one component arranged in the exhaust tract of the internal combustion engine, and in particular can be introduced into the exhaust tract or at least a longitudinal section of the exhaust tract. In particular, the outlet element is arranged on an outlet side of the combustion chamber, wherein the outlet side is, for example, an axial end face of the combustion chamber or the housing element. The outlet side can in particular be referred to as the gas outlet side.

[0010] The component, which is arranged particularly in the exhaust system of the internal combustion engine, is preferably a catalyst. The catalyst can therefore be heated by means of the burner, in particular by means of the burner exhaust gas generated in the combustion chamber of the burner.

[0011] In order to ignite the mixture particularly well using the ignition device, i.e., to significantly improve the ignition capability of the burner or the ignition device, the invention provides at least one heating element, in particular an electric element, designed separately from the ignition device, by means of which the ignition device can be heated, or is heated, particularly for the purpose of removing deposits that have formed on the ignition device. This means that the heating element can be heated, or is heated, in order to heat the ignition device, i.e., to subject it to heat.In other words, it is intended that heat can be provided or generated by means of the heating element in order to apply heat to the ignition device, whereby at least one deposit located on the ignition device can be broken down or broken down, that is, removed from the ignition device.

[0012] The term "degradation" or "degradation" can be understood to refer in particular to the oxidative degradation of the deposits. This means that the deposits can be removed from the ignition device by oxidation. This can be understood in particular as a process of burning off the deposits. The deposits are preferably soot. The oxidation is therefore preferably soot oxidation. The fact that the deposits are located on the ignition device can be understood in particular to mean that the deposits are located on at least one surface of the ignition device, for example, an electrode of the ignition device, which is located in the combustion chamber.Preferably, the ignition device, and in particular at least the surface of the ignition device to be freed from deposits by heating, is arranged at least partially, and in particular predominantly or completely, within the combustion chamber. This means that the ignition device extends at least partially within the combustion chamber. Preferably, the ignition device and the heating element are spaced apart from each other.

[0013] The invention is based in particular on the following findings and considerations: Cold starts and cold start emissions of the internal combustion engine can be particularly important for the engine's emission performance. To keep pollutant emissions from the internal combustion engine especially low, and to reliably achieve certification values ​​such as the EU7 standard, a focus regarding emission development can therefore be placed on cold starts and cold start emissions. Particularly in diesel engines in especially heavy or very heavy vehicles, a burner can be used for this purpose, which can condition the exhaust system (also referred to as the exhaust tract) within a temperature range, which can be described as the operating temperature range, and specifically without causing significant pollutant emissions of its own.However, investigations have shown that soot deposits can accumulate on the ignition device, which may be designed as a spark plug, resulting in a high or even exceptionally high soot load. This can occur particularly during so-called passive burner operation, meaning when the burner is in a deactivated state and the internal combustion engine is transporting high or exceptionally high loads and high or exceptionally high soot mass flows into the exhaust gas, i.e., into the exhaust tract. Without any additional measures, this can lead to soot buildup on the ignition device. In this scenario, the exhaust gas from the exhaust tract can flow into the combustion chamber via the burner outlet, causing soot to deposit on the ignition device. In particular, ignition and combustion of the fuel-air mixture fail to occur in the deactivated state.In other words, no combustion processes take place in the combustion chamber when it is deactivated. Particularly because load collectives, which can also simply be described as collectives in which the vehicle is usually or can be driven, vary so significantly, it cannot be ruled out that particularly high proportions of full load operation with corresponding soot accumulation will occur.

[0014] In contrast, the aforementioned disadvantages can be avoided particularly reliably by means of the burner according to the invention. By heating the ignition device with the heating element, the deposits, especially in the form of soot, can be removed from the ignition device, preferably by oxidation, which can be described as regenerating the ignition device. The ignition device can thus be actively regenerated or cleaned by means of the heating element.

[0015] Overall, it is evident that the burner according to the invention, particularly the heating element, provides soot protection for the ignition device. This means that deposits, especially soot, on the ignition device can be kept to a minimum, thus keeping the ignition device free of deposits. This soot protection significantly improves the ignition capability of the ignition device and / or the burner, enabling the exhaust system, and in particular the component located within it, to be heated more reliably, i.e., more safely, by the burner and / or the burner exhaust gas, thereby keeping pollutant emissions from the internal combustion engine to a minimum.

[0016] For example, it is designed so that the ignition device can be heated, or is heated, to at least 500 degrees Celsius in certain areas by means of the heating element. This means that the heat provided by the heating element can achieve, or is achieved, a temperature of at least 500 degrees Celsius in the ignition device, particularly in certain local areas. Since regeneration and soot oxidation typically occur above 500 degrees Celsius, the ignition device can thus be cleaned of deposits particularly effectively.

[0017] In a further embodiment, the heating element is designed as a glow plug, particularly an electric one. The glow plug can be understood to be, in particular, a glow spark plug. This means that the heating element is designed as a glow plug to remove soot from the ignition system. This results in particularly good soot protection for the ignition system.

[0018] In a further embodiment, it is provided that at least one heatable or heated surface of the heating element is arranged in a fluid flow present in the combustion chamber, particularly a predominant flow, and extending to at least one electrode of the ignition device. This means that the heatable or heated surface of the heating element can be exposed to, or is exposed to, the fluid flow, which flows towards the electrode of the ignition device. As a result, the heat provided by the heating element via its surface can be transported by the fluid flow at least to the electrode of the ignition device in order to heat at least the electrode of the ignition device.This means that the heat provided by the heating element via its surface is transported by the fluid flow to the electrode of the ignition device in order to heat at least the electrode of the ignition device. In other words, the heating element, in particular its surface, and at least the electrode of the ignition device are thermally coupled or connected via the fluid flow, in particular to heat the electrode of the ignition device and thus, in particular, to remove deposits from the electrode. Put another way, the heating element and the ignition device are positioned relative to each other, in particular in the combustion chamber, such that the heat provided by the heating element is carried away by the fluid flow towards the at least one electrode, in particular the electrodes of the ignition device, and there, in particular, leads to oxidation.This allows the heat from the heating element to be transported particularly well to the ignition device, which in turn allows the ignition device to be cleaned of deposits particularly well and, in particular, particularly safely.

[0019] The fluid flow present in the combustion chamber can be understood to mean, in particular, a fluid flow that is to develop or has already developed in the combustion chamber. This fluid flow can, especially during normal burner operation, be a flow of the mixture comprising air and fuel. Particularly during passive burner operation, the flow can be the exhaust gas from the internal combustion engine, which, for example, has flowed back from the exhaust system into the combustion chamber.

[0020] In a further embodiment, the burner has at least one electronic control unit by which the heating element can be controlled, or is controlled, for the intermittent heating of the ignition device, in particular intermittently. In other words, it is provided that the heating of the ignition device by means of the heating element can be effected, or is effected, intermittently. This embodiment is based in particular on the understanding that a continuous exposure of the ignition device, designed, for example, as ignition cores, to the heat provided by the heating element, i.e., in particular to temperatures above 500 degrees Celsius, can be detrimental to the burner. This can be particularly problematic for a sealing element designed to prevent water ingress at the spark plug connector of the spark plug.This can significantly extend the service life of the burner, particularly the ignition device and / or the sealing element. It also effectively prevents damage to the burner, for example to the ignition device and / or the sealing element. Furthermore, the ignition device can be cleaned of deposits in a particularly safe manner.

[0021] In a further embodiment, it is provided that, by means of the electronic computing device, the heating element can be controlled, or is controlled, for heating the ignition device, in particular intermittently, depending on at least one model that characterizes at least one loading state of the ignition device, in particular of the at least one electrode, with the at least one deposit(s). In other words, it is provided that the heating element can be operated, or is operated, depending on the model. This means that the ignition device can be heated, or is heated, by means of the heating element depending on the model.This allows the ignition device to be heated as needed, for example when the model predicts that regeneration of the ignition device is necessary because, for example, a particularly large amount of deposits is located on the ignition device.

[0022] The term "model" can be understood to mean, in particular, a simulation model. The phrase "characterizing the loading state of the ignition device" can be understood to mean, in particular, that the model models, that is, depicts, and especially predicts, the loading state of the ignition device with at least one deposit. Thus, it is specifically provided that, by means of the electronic computing device, the model determines, in particular calculates, at least one quantity, which can be referred to as an output quantity, that characterizes the loading state of the ignition device. This quantity is, for example, the amount of deposits. The feature "depending on the model" can be understood to mean, in particular, that the control or heating can be carried out, or is carried out, depending on the output quantity.This means, in particular, that, for example, the control or heating is carried out when the output variable has a first value, and that the control or heating is omitted, for example, when the output variable has a second value that differs from the first value.

[0023] In a further embodiment, it is provided that the mixture, particularly that located in the combustion chamber, is to be ignited, at least partially, by means of the heating element and thereby combusted, or is ignited and thereby combusted. This means that the ignition, and thus in particular the combustion, of the mixture can be effected, or is effected, by the heating element, especially by the heat provided by the heating element. The heating element is thus designed for ignition, that is, for initiating the combustion processes taking place in the combustion chamber.This allows, in the event that the burner fails to ignite—that is, if the ignition device is currently unable to ignite the mixture—the heating element provides an additional emergency start option for the burner, particularly for an entire burner system. This may, for example, resolve conditions within the burner, especially in the combustion chamber, that are responsible for the failure to ignite, i.e., to start.

[0024] These conditions can therefore resolve themselves, so to speak, without repair. For example, if components of the burner, especially the ignition device, are so sooty that ignition of the mixture is impossible, the heating element can ignite the mixture, thereby initiating the combustion process. This can at least partially remove the soot buildup, making ignition possible again. This significantly increases the burner's operational reliability and, in particular, its lifespan.

[0025] Overall, it is evident that the heating element, positioned, for example, next to the ignition system, can be intermittently and model-based activated repeatedly, particularly during high-load or very high-load operation of the internal combustion engine. This can lead to oxidative soot reduction on the ignition system, thus protecting it from excessive soot buildup. High-load operation of the internal combustion engine can be specifically referred to as high-load engine operation.

[0026] In a further embodiment, the burner has at least one swirl chamber through which the air, in particular the air forming the mixture, flows or is flowing, and which in particular is capable of causing or effecting a swirl flow of the air. This swirl chamber is thus preferably arranged upstream of the combustion chamber in the direction of air flow. The fact that the swirl chamber causes or can cause the swirl flow means, in particular, that the air flows through the swirl chamber in a swirl pattern at least in certain regions, and thus flows through at least a longitudinal region of the swirl chamber in a swirl pattern, and / or flows through at least a flow region arranged downstream of the swirl chamber, which is, for example, located in the combustion chamber, in a swirl pattern.In particular, it is conceivable that the air from the combustion chamber flows into the combustion chamber in a swirling pattern, so that it is preferably provided that the air has a swirling flow at least in the combustion chamber.

[0027] Preferably, the burner has at least one feed element, which can also be referred to as a fuel feed element, arranged, for example, at least partially within the swirl chamber. The feed element is designed, for example, as an injection valve. It is provided that the fuel can be introduced, particularly directly, into the swirl chamber by means of the feed element, or is introduced, particularly injected. In other words, the fuel enters the swirl chamber via the feed element, from which it can then enter the combustion chamber. For example, the feed element has at least one opening through which the fuel, particularly liquid fuel, can flow, and through which the fuel can be introduced, particularly injected, into the swirl chamber.The opening is preferably arranged in the swirl chamber, whereby the injection element, in particular a channel of the injection element through which the fuel can flow, opens into the swirl chamber via the opening.

[0028] Preferably, the swirl chamber is designed to open into the combustion chamber via an outlet opening, particularly directly. In other words, the air flowing through the swirl chamber and / or the fuel introduced into the swirl chamber can be introduced, or is introduced, into the combustion chamber via the outlet opening. This means that the combustion chamber and the swirl chamber are fluidically connected to each other via the outlet opening, particularly directly.

[0029] In a further embodiment, the burner has at least one closure element that is movable between at least one open position and one closed position. This means that the closure element is movable between the open position and the closed position, in particular from the open position to the closed position and / or from the closed position to the open position. "Movement" here can be understood to mean, in particular, movement relative to the housing element. In other words, the closure element is displaceable between the open position and the closed position. In the closed position, the outlet opening is, in particular, completely closed by the closure element. In other words, in the closed position, the outlet opening is, in particular, completely covered by the closure element.In the closed position, this prevents air and / or fuel from entering the swirl chamber through the outlet opening, which is closed. In the open position, the outlet opening is at least partially, and in particular predominantly or completely, uncovered by the closing element. This means that in the open position, the closing element does not cover the outlet opening. Therefore, in the open position, air and / or fuel can enter the combustion chamber from the swirl chamber through the open outlet opening. Thus, the closing element, particularly in the closed position, provides soot protection for the swirl chamber and / or directs airflow to the burner.In the closed position, this prevents a soot-laden flow from the combustion chamber back into the swirl chamber via the outlet opening, thus reliably preventing deposits, such as soot, in the swirl chamber and / or on the feed element. This flow could be the burner exhaust or the exhaust gas from the internal combustion engine, whereby the exhaust gas from the internal combustion engine may, for example, have flowed undesirably from the exhaust system into the combustion chamber. By preventing these deposits, the proper functioning of the swirl chamber, especially the air guide, and the feed element can be ensured.

[0030] In a further embodiment, the swirl chamber is provided for, or at least partially defined by, at least one wetting element. In other words, the wetting element is provided for, or arranged in, or on the swirl chamber. It is provided that when the fuel is introduced, particularly into the swirl chamber, the wetting element is wettable by the fuel, particularly directly, forming at least one fuel film. In other words, the fuel, particularly the fuel exiting the introduction element through the opening, is applied to the wetting element as a fuel film.It is provided that the fuel film, which is formed or applied, in particular to the wetting element, can be exposed to, or is exposed to, the air flowing through the swirl chamber, in particular in a swirling motion. This causes the fuel to be atomized, i.e., in droplet form, and released from the fuel film at the outlet opening. The atomized fuel is then introduced directly into the combustion chamber at the outlet opening and transported, in particular, to the ignition device. In other words, the mixture is formed by the fuel applied, in particular sprayed, to the wetting element being released in droplet form at the outlet opening by an airflow passing through the swirl chamber.This allows for particularly good atomization and thus excellent mixing of the mixture, especially without requiring particularly high injection pressure. The wetting element can therefore be understood to be, in particular, a film layer or a film support, and can also be referred to as a prefilmer.

[0031] This embodiment is based in particular on the following findings and considerations: Investigations have shown that, especially during passive burner operation—that is, when the burner is essentially off and the internal combustion engine is transporting particularly high loads and particularly high soot mass flows into the exhaust gas—the injection element, referred to in particular as the injector, and, for example, a delicate air guide in the prefilmer can become fouled or clogged very quickly, for example with soot. This can lead to a deterioration of the mixture formation or a reduction in the quantities of air and fuel. To prevent this, a sealing element, designed, for example, as a flap, can be used. This keeps the prefilmer free of deposits, especially soot, thereby ensuring particularly good mixture formation.

[0032] A second aspect of the invention relates to an internal combustion engine for a motor vehicle, wherein the internal combustion engine comprises a burner, in particular arranged in an exhaust tract of the internal combustion engine, according to the first aspect of the invention. 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.

[0033] A third aspect of the invention relates to a method for operating a burner for an exhaust tract through which exhaust gas from an internal combustion engine of a motor vehicle flows or through which exhaust gas flows. The burner is preferably a burner according to the first aspect of the invention. The internal combustion engine is preferably an internal combustion engine according to the second aspect of the invention. Advantages and advantageous embodiments of the first and second aspects of the invention are to be regarded as advantages and advantageous embodiments of the third aspect of the invention, and vice versa.

[0034] The burner has at least one ignition device and at least one combustion chamber in which a mixture comprising air and fuel is to be ignited by means of the ignition device and thereby burned, or is ignited and thereby burned.

[0035] In order to ignite the mixture particularly well, i.e. to particularly improve the ignition capability of the burner or the ignition device, it is provided according to the invention that the ignition device is heated by means of at least one heating element of the burner, which is designed separately from the ignition device, in particular an electric one, especially for the oxidative degradation of deposits arranged on the ignition device.

[0036] Further advantages, features, and details of the invention will become apparent from the following description of preferred embodiments and from the drawing. The features and combinations of features mentioned above in the figure description and / or shown in the single figure alone can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention.

[0037] The drawing shows in the single figure a schematic partial sectional view of a burner according to the invention.

[0038] The single figure shows, in a schematic partial sectional view, a burner 10 for an exhaust tract through which exhaust gas from an internal combustion engine of a motor vehicle flows or through which exhaust gas flows. Preferably, the motor vehicle is driven by means of the internal combustion engine.

[0039] The term "exhaust system" can refer specifically to the exhaust system of an internal combustion engine. In certain operating conditions or situations of the internal combustion engine, a high exhaust gas temperature may be desirable, for example, to quickly heat and / or maintain the temperature of an exhaust aftertreatment device located within the exhaust system. However, in these operating conditions or situations, the exhaust gas temperature may be insufficiently high. The exhaust system, and in particular the exhaust aftertreatment device, can be heated and / or maintained by means of the burner 10. This means that, in addition to heating and / or maintaining the temperature using the exhaust gas, the exhaust system, and especially the exhaust aftertreatment device, can also be heated and / or maintained by means of the burner.This exhaust gas can be understood in particular as exhaust gas generated in a combustion chamber of the internal combustion engine from a fuel-air mixture. The combustion chamber, which is designed, for example, as a cylinder, is separate from the burner 10.

[0040] The internal combustion engine is, for example, a diesel engine. The exhaust aftertreatment system includes, for example, at least one catalyst or is designed as a catalyst. The exhaust aftertreatment system or the catalyst is, for example, an oxidation catalyst, in particular a diesel oxidation catalyst, a nitrogen oxide storage catalyst, an SCR catalyst, or a particulate filter, in particular a diesel particulate filter. The exhaust gas from the internal combustion engine can be cleaned by means of the exhaust aftertreatment system.

[0041] The burner 10 has at least one combustion chamber 12 in which a mixture comprising air and a fuel, in particular a liquid fuel, is to be ignited and thereby combusted. This means that the burner 10 can ignite and combust the mixture in the combustion chamber 12, in particular by forming a flame and in particular by providing burner exhaust gas.

[0042] For example, the fuel is the fuel that is burned in the combustion chamber, which is designed as a cylinder, for instance, of the internal combustion engine. Therefore, the fuel can be used to refer to the combustion chamber. However, the exhaust gas from the burner is not the exhaust gas produced in the combustion chamber of the internal combustion engine.

[0043] In the exemplary embodiment, the burner 10 has at least one injection element 14 by means of or via which the fuel, in particular for forming the mixture, can be introduced into the combustion chamber 12, in particular directly. The injection element 14 is, for example, designed as an injection valve.

[0044] For example, the burner 10 has at least one ignition device 16, in particular arranged in the combustion chamber 12, by means of which the mixture comprising air and fuel is to be ignited and thereby combusted. The ignition device 16 is, for example, designed as a spark plug, glow plug or glow pin. In the present case, the ignition device 16 has two electrodes 16a, 16b by means of which the mixture is to be ignited, in particular by providing at least one ignition spark.

[0045] The burner 10 in this embodiment has at least one housing element 18, which can be referred to in particular as a combustion chamber housing. The housing element 18 at least partially, and in particular predominantly or completely, delimits the combustion chamber 12. In this embodiment, the combustion chamber 12, or the housing element 18, is at least substantially cylindrical. Furthermore, in this embodiment, the housing element 18 has at least one side wall 20, which at least partially, and in particular predominantly or completely, delimits the combustion chamber 12 in its radial direction 22. The housing element 18 also has, for example, at least one bottom element 24, which at least partially delimits the combustion chamber 12 in its axial direction 26, in particular at one end. The bottom element 24 and the side wall 20 can be formed integrally or separately.The base element 24 can in particular be referred to as a base wall. In the exemplary embodiment, the side wall 20 and the base element 24 are part of a lower housing part 28 of the housing element 18, wherein at least one upper housing part 29 of the housing element 18 adjoins the lower housing part 28, for example in axial direction 26 in the direction away from the base element 24.

[0046] The ignition device 16, designed as a spark plug, has, for example, a spark plug base 17. For example, the ignition device 16, in particular the spark plug base 17, rests against the housing element 18, in particular the upper housing part 29, via at least one sealing element (not shown in the single figure), in particular directly. This means that the ignition device 16, in particular the spark plug base 17, can be supported or is supported against the housing element 18 via the sealing element, in particular directly. In other words, the ignition device 16, in particular the spark plug base 17, can be sealed or is sealed against the housing element 18, in particular against an environment, by means of the sealing element. The environment can be understood to be, in particular, the environment of the combustion chamber 12, in particular the burner 10. In particular, the sealing element is provided to prevent water ingress at the spark plug connector.

[0047] In the exemplary embodiment, the burner 10 has at least one outlet element 30, which in particular at one end of the combustion chamber 12, preferably in the axial direction 26, at least partially limits the combustion chamber 12 and which has at least one burner outlet opening 32, in particular through which the burner exhaust gas can flow, and through which the burner exhaust gas produced by the combustion of the mixture can be discharged from the combustion chamber 12 for heating the exhaust tract of the internal combustion engine, in particular the exhaust aftertreatment device, and in particular can be introduced into the exhaust tract, for example for supplying the exhaust aftertreatment device.The burner exhaust gas or flame can therefore be discharged from the combustion chamber 12, in particular from the burner 10, via the burner outlet opening 32, and especially introduced into the exhaust tract, for example into at least one duct element of the exhaust tract. The exhaust gas or flame can heat and / or keep the exhaust tract, and in particular the exhaust aftertreatment system, warm.

[0048] In this embodiment, the outlet element 30 has a plurality of burner outlet openings 32, which are preferably designed as through-openings. The burner exhaust gas or flame can be discharged from the combustion chamber 12, particularly from the burner 10, via the burner outlet openings 32 to heat the exhaust tract of the internal combustion engine, especially the exhaust aftertreatment system, and can be introduced, for example, into the exhaust tract or the ducting element. This allows the exhaust tract, especially the exhaust aftertreatment system, to be heated or kept warm particularly effectively. The burner outlet openings 32 are permeable to the burner exhaust gas. In this embodiment, the outlet element 30 is plate-shaped, i.e., designed as a plate, which can be referred to as an outlet plate.In the exemplary embodiment, the outlet element 30 is designed as a perforated plate, in particular as a perforated disc. The outlet element 30 is, for example, at least partially formed by the base element 24. In particular, the outlet element 30 can be the base element 24, whereby the base element 24 can have the burner outlet openings 32.

[0049] In the exemplary embodiment, the burner 10 has at least one swirl system, which in this case has at least one swirl chamber 34 through which air can flow or is flowed. The swirl chamber 34 can have one swirl region or several, in particular different, swirl regions, which can be understood as different sub-regions of the swirl system, in particular of the swirl chamber 34. The individual swirl regions can also be considered as individual swirl chambers, whereby the swirl system can also have several swirl chambers. Furthermore, the burner 10 in this case has at least one air supply section 36 through which air can flow or is flowed, and through which the air can be introduced or is introduced into the swirl chamber system, in particular into the swirl chamber 34.In the present case, the fuel can be introduced, in particular injected, into the swirl chamber 34 by means of the introduction element 14, which leads, in particular directly, into the combustion chamber 12 via an outlet opening 38, through which air and / or fuel can flow.

[0050] In this embodiment, the swirl chamber 34 is at least partially bounded by at least one wetting element 40, which is designed, for example, as a film layer, which can in particular be referred to as a pre-filmer. When the fuel is introduced, the wetting element 40 can be wetted by the fuel, forming a fuel film. The wetting element 40 is, for example, a surface, particularly an inner surface, of a component that at least partially bounds or forms the swirl chamber 34. The fuel film can be acted upon by the air flowing through the swirl chamber, which is introduced into the swirl chamber 34, in particular via the air supply section 36. This causes at least a portion of the fuel to be atomized and released from the fuel film at the outlet opening 38, in order to introduce the atomized fuel into the combustion chamber 12 at the outlet opening 38.The concept regarding mixture formation in the burner 10 thus includes an injection of the fuel onto the wetting element 40, from which the fuel is then detached in droplet form at the outlet opening 38 by airflow and transported by the swirling air introduced into the combustion chamber 12 to the ignition device 16, in particular to the electrodes 16a, 16b.

[0051] In the exemplary embodiment, the burner 10 has at least one closure element 44 that is movable between at least one open position and one closed position 42. This closure element is, for example, movably held or mounted on the housing element 18, particularly between the open and closed positions 42. A holding device 46 is thus provided, for example, by means of which the closure element 44 is held, particularly at least indirectly or directly, on the housing element 18, especially on the upper housing part 29. This closure element 44 prevents soot-containing gas from flowing back from the combustion chamber 12 into the swirl chamber 34 via the outlet opening 38, thereby preventing soot deposits in the swirl chamber 34 and / or on the insertion element 14, and in particular on the wetting element 40.

[0052] In the present embodiment, the locking element 44 is designed to pivot about a pivot axis 48 between the open position and the closed position 42. The locking element 44 is therefore preferably designed as a locking flap. As shown in the single figure, in this embodiment the locking element 44 rests, in particular directly, against the housing element 18 in the closed position 42, especially against a wall that at least partially delimits the combustion chamber 12 and / or the swirl chamber 34. In the open position, the locking element 44 is preferably spaced apart from the housing element 18, so that in the open position the locking element 44 preferably does not rest against the housing element 18 or against the wall.

[0053] To ensure particularly good ignition of the mixture, and especially to provide soot protection for the ignition device 16, at least one heating element 50, preferably electric, is provided, separate from the ignition device 16. This heating element is used to heat the ignition device 16, and in particular at least one of the electrodes 16a, 16b. This is particularly important to keep the level of deposits on the ignition device 16 or the electrodes 16a, 16b as low as possible, and thus to remove the deposits, especially oxidative deposits, from the ignition device 16 or the electrodes 16a, 16b. The deposits are preferably soot.Thus, by means of the heating element 50, a sufficiently high temperature, for example of more than 500 degrees Celsius, can be provided on at least one surface of the ignition device 16, in particular at least one of the electrodes 16a, 16b, in order to cause a burning of soot on the surface.

[0054] The fact that the heating element 50 is electric can be understood in particular to mean that electrical energy can be converted into heat by means of the heating element 50, especially to heat the ignition device 16. For this purpose, the electric heating element 50 has, for example, at least one currentable heating coil, which, for example, has several wound loops.

[0055] In this embodiment, the heating element 50 is designed as a glow plug 52. The glow plug 52 has at least one base body 54, through which the glow plug 52 is attached to the housing element 18, in particular to the upper housing part 29, by passing through the housing element 18. Furthermore, the glow plug 52 has at least one heatable or heated surface 56, which can be referred to as a heating surface. The surface 56 is located at least partially, and in particular predominantly or completely, within the combustion chamber 12. As can be seen in the single figure, the surface 56 is spaced apart from the ignition device 16.

[0056] The surface 56 is preferably formed by a partial area of ​​the glow plug 52, wherein this partial area preferably projects obliquely or perpendicularly from the base body 54, and in particular has a smaller diameter than the base body 54.

[0057] Preferably, the heatable or heated surface 56 is arranged in a fluid flow present or to be formed in the combustion chamber 12 and extending to at least one of the electrodes 16a, 16b, whereby heat provided by the heating element 50 via the surface 56 can be transported by means of the fluid flow to at least one electrode 16a, 16b of the ignition device 16 in order to heat at least one electrode 16a, 16b of the ignition device 16. The fluid flow can, for example, be the swirl-entrained mixture introduced into the combustion chamber 12 via the outlet opening 38 or exhaust gas from the internal combustion engine entering the combustion chamber 12 from the exhaust tract via the respective burner outlet opening 32.

[0058] In the exemplary embodiment, the internal combustion engine, in particular the burner 10, has at least one electronic computing device 58 by means of which the heating element 50 can be controlled, or is controlled, for intermittent heating of the ignition device 16. This allows the thermal stress on the sealing element to be kept particularly low, thereby significantly increasing the service life of the sealing element.

[0059] Alternatively or additionally, it is provided that the heating element 50 can be controlled or is controlled by means of the electronic computing device 58 depending on at least one model which characterizes the loading state of the ignition device 16 with the at least one deposit.

[0060] For example, it is intended that the mixture is ignited and thereby combusted by means of the heating element 50. This means that sufficient energy, in particular thermal energy in the form of heat, can be provided by means of the heating element 50 to ignite the mixture located in the combustion chamber 12 and thereby initiate combustion of the mixture. The heating element 50 can thus function as a replacement, in particular as an emergency start option, for the ignition device 16.

[0061] Overall, it is evident that the heating element 50, positioned next to the ignition device 16, can be intermittently activated in the event of high-load engine operation, leading to oxidative soot reduction on the ignition device 16, thus protecting it from excessive soot loading. Soot loading can occur with NO xOptimized engines present a fundamental problem, which is also known to affect exhaust system sensors. The heating element 50 can therefore be used to implement a measure to protect the ignition device 16 from soot buildup, which is in particular an ignition element based on closely spaced electrodes 16a, 16b. Reference symbol list 10 burners 12 Combustion chamber 14 Insertion element 16 Ignition device 16a first electrode 16b second electrode 17 Spark plug base 18 Housing element 20 side wall 22 radial direction 24 floor elements 26 axial direction 28 Lower housing part 29 Housing top 30 Exit element 32 Burner outlet opening 34 Swirl chamber 36 Air supply section 38 Exit opening 40 wetting element 42 Closing position 44 Locking element 46 Holding device 48 Swivel axis 50 heating elements 52 Glow plug 54 Basic shapes 56 surface 58 electronic computing equipment QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2021 001 580 A1

[0002]

Claims

[1] Burner (10) for an exhaust tract through which exhaust gas of an internal combustion engine of a motor vehicle flows, with an ignition device (16) and with a combustion chamber (12) in which a mixture comprising air and a fuel is to be ignited by means of the ignition device (16) and thereby burned, characterized by at least one heating element (50) designed separately from the ignition device (16), by means of which the ignition device (16) can be heated. [2] Burner (10) according to claim 1, characterized by , that the heating element (50) is designed as a glow plug (52). [3] Burner (10) according to claim 1 or 2, characterized by, that at least one heatable surface (56) of the heating element (50) is arranged in a fluid flow present in the combustion chamber (12) and leading to an electrode (16a, 16b) of the ignition device (16), whereby heat provided by the heating element (50) via the surface (56) of the heating element (50) can be transported to the electrode (16a, 16b) of the ignition device (16) by means of the fluid flow, in order to heat at least the electrode (16a, 16b) of the ignition device (16). [4] Burner (10) according to any one of the preceding claims, characterized by an electronic computing device (58) by means of which the heating element (50) can be controlled for intermittent heating of the ignition device (16). [5] Burner (10) according to any one of the preceding claims, characterized byan electronic computing device (58) by means of which, depending on at least one model which characterizes a loading state of the ignition device (16) with at least one deposit, the heating element (50) can be controlled to heat the ignition device (16). [6] Burner (10) according to any one of the preceding claims, characterized by , that the mixture is to be ignited by means of the heating element (50) and thereby burned. [7] Burner (10) according to any one of the preceding claims, characterized by • at least one swirl chamber (34) through which air can flow and at least one introduction element (14) by means of which the fuel can be introduced into the swirl chamber (34), which opens into the combustion chamber (12) via an outlet opening (38), and • at least one locking element (44) movable between at least one open position and one closed position (42), wherein in the closed position (42) the outlet opening (38) is closed by the locking element (44) and in the open position the outlet opening (38) is at least partially released by the locking element (44). [8] Burner (10) according to claim 7, characterized by , that the swirl chamber (34) is at least partially bounded by at least one wetting element (40) which, when the fuel is introduced, can be wetted by the fuel forming a fuel film, wherein the fuel film can be acted upon by the air flowing through the swirl chamber (34), whereby the fuel can be detached from the fuel film by atomization at the outlet opening (38) in order to introduce the atomized fuel at the outlet opening (38) into the combustion chamber (12). [9] Internal combustion engine for a motor vehicle, comprising a burner (10) according to any of the preceding claims. [10] Method for operating a burner (10) for an exhaust tract through which exhaust gas of an internal combustion engine of a motor vehicle flows, in which the burner (10) has an ignition device (16) and a combustion chamber (12) in which a mixture comprising air and a fuel is to be ignited by means of the ignition device (16) and thereby combusted, characterized by that the ignition device (16) is heated by means of at least one heating element (50) designed separately from the ignition device (16).

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