Patent Application
20240175385
The invention relates to a burner for an exhaust gas tract that can be flowed through by exhaust gas of an internal combustion engine of a motor vehicle. The invention further relates to a motor vehicle having at least one such burner.
Motor vehicles having internal combustion engines and exhaust gas systems, which are also described as exhaust gas tracts, are known from the general prior art and in particular from series vehicle construction. The respective exhaust gas tract can be flowed through by exhaust gas of the respective internal combustion engine, also described as an internal combustion motor. In some operating states or operating situations of the respective internal combustion engine, a high temperature of the exhaust gas can be desirable, for example to be able to quickly heat and/or keep warm an exhaust gas aftertreatment device arranged in the exhaust gas tract, wherein, however, the temperature of the exhaust gas is only insufficiently high in these operating states or situations.
DE 37 29 861 C2 discloses a burner for an exhaust gas tract that can be flowed through by exhaust gas of an internal combustion engine of a motor vehicle, having a combustion chamber in which a mixture comprising air and a liquid fuel is to be ignited and thus to be combusted. The burner has an inner swirl chamber, that can be flowed through by the first part of the air and that causes a turbulent flow of the first part of the air, and that has a first outflow opening via which the first part of the air can be removed from the inner swirl chamber. By means of a first introduction element, the liquid fuel can be introduced into the inner swirl chamber. A second swirl chamber surrounds the inner swirl chamber in the peripheral direction in at least one longitudinal region. The second swirl chamber is flowed through by a second part of the air and causes a turbulent flow of the second part of the air. The second swirl chamber has a second outflow opening, via which the second part of the air and the first part of the air and the liquid fuel can be introduced into the combustion chamber out of the inner swirl chamber. The first outflow opening ends in the flow direction on an end edge machined in a targeted manner, the end edge being formed by an atomizing lip and tapering in the flow direction of the first part of the air flowing through the outflow opening up to the end edge and ending on the end edge.
US 2005/0 039 456 A1 discloses a burner having an inner swirl chamber that can be flowed through by a first part of the air and causes a turbulent flow of the first part of the air, and having an outer swirl chamber that can be flowed through by a second part of the air and causes a turbulent flow of the second part of the air, in which the turbulent flow of a first part of the air runs contrary to the turbulent flow of a second part of the air.
DE 10 2008 026 477 A1 discloses a burner having an inner swirl chamber having a first outflow opening and an outer swirl chamber having a second outflow opening, wherein the outer swirl chamber, and thus a second outflow opening are formed by a component element and an anti-recirculation plate extends outwards from the component element in the radial direction of the respective outflow opening, the anti-recirculation plate protruding outwards over at least a partial region of the component element in the radial direction of the respective outflow opening.
The object of the present invention is thus to create a burner for an exhaust gas tract and a motor vehicle having such a burner, such that at least one component of the exhaust gas tract can be particularly quickly and efficiently heated.
A first aspect of the invention relates to a burner for an exhaust gas tract that can be flowed through by exhaust gas of an internal combustion engine also described as an internal combustion motor of a motor vehicle. This means that in its completely produced state, the motor vehicle, which can preferably be designed as a motor car and particularly preferably as a passenger car, has the internal combustion engine and the exhaust gas tract and can be driven by means of the internal combustion engine. During a fired operation of the internal combustion engine, combustion processes take place in the internal combustion engine, in particular in at least one or several 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 gas tract, and consequently flow through the exhaust gas tract, which is also described as an exhaust gas system. At least one component, e.g., an exhaust gas aftertreatment element for after treating the exhaust gas, can be arranged in the exhaust gas tract. The exhaust gas aftertreatment element is a catalytic converter, for example, in particular an SCR catalytic converter, wherein for example a selective catalytic reduction (SCR) can be catalytically supported and/or caused by means of the SCR catalytic converter. In the selective catalytic reduction, nitrogen oxides potentially contained in the exhaust gas are at least partially removed from the exhaust gas, as the nitrogen oxides react with ammonia in the selective catalytic reduction to form nitrogen and water. For example, the ammonia is provided by an in particular liquid reduction agent. The exhaust gas aftertreatment element can also 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.
The burner has a combustion chamber in which a mixture that comprises air and a liquid fuel can be ignited and thus combusted. By combusting the mixture, exhaust gas of the burner, in particular of the combustion chamber, is generated, of which the exhaust gas is also described as burner exhaust gas. The burner exhaust gas can for example flow out of the combustion chamber and into the exhaust gas tract, in particular at an introduction point, which is for example arranged upstream of the component in the flow direction of the exhaust gas of the internal combustion engine flowing through the exhaust gas tract. The burner exhaust gas can consequently flow through the component, for example, whereby the component can be heated, i.e., warmed. It is further conceivable that the burner exhaust gas can flow out of the combustion chamber and into the exhaust gas tract, and is thus mixed with the exhaust gas of the internal combustion engine flowing through the exhaust gas tract and/or with a gas flowing through the exhaust gas tract, whereby the exhaust gas of the internal combustion engine or the gas is warmed. In other words, a particularly high temperature, also described as an exhaust gas temperature, of the exhaust gas of the internal combustion engine or of the gas can thus be obtained. The component can be warmed by the high exhaust gas temperature, as 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 gas tract at the previously specified introduction point, and thus into the exhaust gas or gas flowing through the exhaust gas tract. For example, an ignition device that can in particular be operated electrically is arranged in the combustion chamber, by means of which, for example, at least one ignition spark can be provided, i.e., generated, for igniting the mixture, in particular in the combustion chamber and/or using electrical energy or the current. The ignition device, for example, is a glow plug or a spark plug.
The burner has an inner swirl chamber that can be flowed through by a first part of the air forming the mixture and that causes a turbulent flow of the first part of the air, the inner swirl chamber thus preferably being arranged upstream of the combustion chamber in the flow direction of the first part of the air flowing through the inner swirl chamber. The inner swirl chamber has in particular exactly one first outflow opening that can be flowed through by the first part of the air flowing through the inner swirl chamber and via which the first part of the air flowing through the first outflow opening can be removed from the inner swirl chamber and for example introduced into the combustion chamber. The feature that the inner swirl chamber causes or can cause a turbulent flow of the first part of the air flowing through the inner swirl chamber should in particular be understood to mean that the first part of the air flows through the swirl chamber in a turbulent manner, and thus flows through at least one longitudinal region of the swirl chamber in a turbulent manner and/or the first part of the air only has its turbulent flow at least in a first flow region arranged downstream of the inner swirl chamber and outside of the inner swirl chamber, which first flow region is for example arranged in the combustion chamber. It is in particular conceivable that the first part of the air flows out of the inner swirl chamber via the first outflow opening in a turbulent manner and/or flows into the combustion chamber in a turbulent manner, such that it is particularly preferably provided that the first part of the air has its turbulent flow at least in the combustion chamber.
The burner additionally has an introduction element, in particular an injection element, which has at least or exactly one exit opening that can be flowed through by the liquid fuel. The exit opening is arranged in the inner swirl chamber, such that the introduction element, in particular the injection element, or a conduit of the introduction element that can be flowed through by the liquid fuel leads into the inner swirl chamber via the exit opening. By means of the introduction element, the fuel flowing through the exit opening can be introduced, in particular injected, in particular directly, into the inner swirl chamber via the exit opening, such that the first outflow opening can also be flowed through by the liquid fuel that has exited, in particular been injected out of the introduction element via the exit opening and has thus been introduced, in particular injected into the inner swirl chamber, in particular directly. In particular, this means that the first part of the air and the fuel can flow through the first outflow opening along a shared first flow direction and can thus flow out of the inner swirl chamber.
The burner further comprises an outer swirl chamber that surrounds at least one longitudinal region of the inner swirl chamber and preferably also the first outflow opening in the peripheral direction of the inner swirl chamber, in particular completely continuously. For example, the peripheral direction of the inner swirl chamber runs around the previously specified first flow direction, which coincides for example with the axial direction of the inner swirl chamber and thus the first outflow opening. It is preferably provided that the inner swirl chamber ends on the first outflow opening or on the end of the latter 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, and thus in the axial direction of the inner swirl chamber and thus the first outflow opening. The outer swirl chamber can be flowed through by a second part of the air, and is designed to cause a turbulent flow of the second part of the air. This should in particular be understood to mean that the second part of the air flows into the outer swirl chamber, and thus flows through at least one part or longitudinal region of the outer swirl chamber in a turbulent manner, and/or the second part of the air has its turbulent flow in a second flow region arranged downstream of the outer swirl chamber in the flow direction of the second part of the air flowing through the outer swirl chamber, the second flow region for example coinciding with the previously specified first flow region, wherein the second flow region can for example be arranged outside of the outer swirl chamber and for example within the combustion chamber. It is further conceivable that the previously specified first flow region is arranged outside of the outer swirl chamber. In other words again, it is conceivable that the second part of the air flows out of the outer swirl chamber in a turbulent manner and/or flows into the combustion chamber in a turbulent manner, such that it is preferably provided that the second part of the air has its turbulent flow at least in the combustion chamber.
The outer swirl chamber has in particular exactly one second outflow opening that can be flowed through by the second part of the air flowing through the outer swirl chamber, by the fuel flowing through the first outflow opening and by the first part of the air flowing through the inner swirl chamber and the first outflow opening, and that is for example arranged downstream of the first outflow opening in the flow direction of the parts and the fuel, the second part of the air being able to be removed from the outer swirl chamber and the parts of the air and the fuel being able to be introduced into the combustion chamber via the second outflow opening. In particular, the parts of the air and the fuel can flow along a second flow direction through the second outflow opening, and thus via the second outflow opening into the combustion chamber, wherein for example the second flow direction runs in parallel with the first flow direction or coincides with the first flow direction. It is further preferably provided that the second flow direction runs in the axial direction of the outer swirl chamber, and thus coincides with the axial direction of the outer swirl chamber, such 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, as 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 part of the air and in the flow direction of the fuel, and as the outer swirl chamber preferably surrounds the first outflow opening, the first outflow opening is for example arranged in the outer swirl chamber. In particular, it is conceivable that the outer swirl chamber ends on the second outflow opening, in particular on the end of the latter, in particular in the flow direction of the second part of the air flowing through the second outflow opening.
For example, to generate the respective turbulent flow, the respective swirl chamber can have at least one or several swirl generators, by means of which the respective turbulent flow can be or is generated. The respective swirl generator is in particular arranged in the respective swirl chamber. In particular, the swirl generator can for example be a guide vane, by means of which, for example, the respective part, i.e., the respective air forming the respective part, is diverted at least or exactly once, in particular by at least or exactly 70 degrees, in particular by approx. 90 degrees, i.e., for example, by 70 to 90 degrees. The turbulent flow should in particular be understood to mean a flow that extends turbulently or at least substantially helically or as a helix around the respective axial direction of the respective swirl chamber or the respective outflow opening. In particular, the respective axial direction of the respective outflow opening runs perpendicular to a plane in which the respective outflow opening runs. For example, the respective axial direction of the respective outflow opening coincides with the respective axial direction of the respective swirl chamber. The respective outflow opening is for example also described as a respective nozzle, of which the cross-section, which can be flowed through by the respective part of the air, need not, however, necessarily taper along the respective flow direction. Thus, for example, the second outflow opening is also described as an outer nozzle or second nozzle, whereby, for example, the first outflow opening is also described as an inner nozzle or first nozzle.
By causing the respective turbulent flow, the air can particularly advantageously be mixed with the liquid fuel, in particular even only over a small mixing path, in particular in the combustion chamber, such that a particularly advantageous mixture preparation can be obtained, i.e., the mixture can be formed particularly advantageously. In particular, the fuel can first be mixed with the first part of the air particularly well, in particular in the inner swirl chamber, in particular due to the turbulent flow of the first part, in particular in the inner swirl chamber. Additionally, the fuel and also, for example, the first part that has already mixed with the fuel can be particularly advantageously mixed with the second part of the air, in particular in the outer swirl chamber and/or in the combustion chamber, as the second part of the air also has an advantageous turbulent flow. Overall, the parts of the air and the fuel can be mixed particularly advantageously due to the turbulent flows, such that an advantageous mixture preparation can be produced.
So that a particularly advantageous mixture preparation can be obtained and the components can be heated and/or kept warm particularly quickly and efficiently, it is provided according to the invention that the burner has at least or exactly one feeding conduit that can be flowed through by the air that leads, in particular directly, into an air chamber shared by the swirl chambers and by which the swirl chambers that can be flowed through by the parts of the air along the respective flow direction are respectively at least partially, in particular at least substantially and thus more than half or completely overlapped in a direction contrary to the respective flow direction. The air chamber extends both along a first direction running in parallel with the respective flow direction and along a second direction running perpendicular to the respective flow direction without interruption, i.e., continuously. The air chamber is a supply chamber shared by the swirl chambers, as the swirl chambers can be or are provided with the air or with the parts of the air from the air chamber. In particular, this means the following: The air that flows through the feeding conduit and is guided into the air chamber shared by the swirl chambers via or by means of the feeding conduit is divided into the parts, i.e., into the first part of the air and into the second part of the air, such that the first part of the air is guided out of the air chamber into the inner swirl chamber and then flows through the inner swirl chamber, and such that the second part of the air is guided out of the air chamber into the outer swirl chamber and then flows through the outer swirl chamber. The burner according to the first aspect of the invention is thus a burner without a pre-chamber, such that a particularly advantageous mixture preparation can be produced in a particularly simple, installation space-, weight- and cost-saving manner.
So that a particularly advantageous mixture preparation can be obtained and, consequently, the components can be heated and/or kept warm particularly quickly and efficiently, in a second aspect of the invention it is provided that the burner has at least one closing element that can be moved relative to the outflow openings between at least one closed position closing and thus completely blocking at least one of the outflow openings and at least one open position releasing the at least one outflow opening. In the closed position, no gases and no particles, in particular from the combustion chamber, can penetrate into the at least one outflow opening or through the at least one outflow opening, such that no gases, e.g., the burner exhaust gas or the exhaust gas of the combustion engine, and no particles can penetrate an air conduit to guide the air or a fuel conduit to guide the fuel. A particularly high lifespan of the burner can thus be generated via a particularly advantageous mixture preparation, as the mixture preparation is not damaged by particles or gases that have penetrated undesired regions of the burner.
So that the component, for example designed as an exhaust gas aftertreatment device or as an exhaust gas aftertreatment system, can be particularly quickly and efficiently heated, in particular even if the exhaust gas of the internal combustion engine only has a low temperature, it is provided in an embodiment 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, on an end edge that has been machined in a targeted manner and is thus sharp or knife-sharp and that is formed by an atomizing lip in particular designed as a solid body, which tapers up to the end edge 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 and ends on the end edge. This means that the atomizing lip has a taper tapering in the first flow direction and thus in particular towards the combustion chamber that ends, in particular only ends on the end edge. Thus, and in particular due to the targeted machining of the end edge, the taper or the atomizing lip is sharp-edged. In other words, the atomizing lip ends in a sharp edge, whereby a particularly advantageous mixture preparation can be produced.
For example, the mixture is combusted in the combustion chamber while forming a flame, wherein the fuel can in particular be advantageously mixed with the air via the turbulent flow, and wherein the flame of the combustion chamber can advantageously be stabilized in particular due to the turbulent flows. For this purpose, a combustion-induced bursting of vortices can be generated, in particular via the turbulent flows. For this purpose, for example, the air flowing into the combustion chamber in the respective swirl chamber is first deflected by approximately 70 degrees or by approximately 90 degrees, in particular in a range from 70 degrees to 90 degrees, which can for example be realized via the respective swirl generator. For example, the inner swirl chamber and the outer swirl chamber form a swirl chamber also described as a total swirl chamber, which is sub-divided in the invention into the inner swirl chamber and the outer swirl chamber. The inner swirl chamber and the outer swirl chamber are preferably separated by a dividing wall in particular designed as a solid body, in particular in the radial direction of the respective swirl chamber. It is conceivable that the dividing wall surrounds at least the specified longitudinal region of the inner swirl chamber in the peripheral direction of the inner swirl chamber running around the axial direction of the inner swirl chamber, in particular completely continuously, such that for example at least the longitudinal region of the inner swirl chamber is formed or delimited outwards in the radial direction of the inner swirl chamber, in particular directly, by the dividing wall. It is further conceivable that at least a second longitudinal region of the outer swirl chamber is formed or delimited inwards in the radial direction of the outer swirl chamber, in particular directly, by the dividing wall. It is in particular conceivable that the longitudinal regions of the swirl chambers are arranged at the same height in the axial direction of the respective swirl chamber. During an 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. The fuel can thus already be advantageously mixed with the first part of the air in the inner swirl chamber. The introduction element, in particular the injection element, can be an injection nozzle, of which the outflow opening is for example arranged in or on an end face or end surface of the injection element, of which the end face or end surface runs in an end face or end surface plane running perpendicular to the axial direction of the respective swirl chamber. It is further conceivable that the introduction element is designed as a lance, which has a longitudinal extension that coincides for example with the respective axial direction of the respective swirl chamber or the respective outflow opening. For example, the lance has at least or exactly, in particular at least or exactly two exit openings, which can be designed as holes, in particular as transverse holes. The exit opening has a through direction along which the fuel can flow through the exit opening. In particular, if the introduction element is designed as an injection nozzle, the through direction of the exit opening runs in parallel with the respective axial direction of the respective swirl chamber or the through direction coincides with the respective axial direction of the respective swirl chamber or the respective outflow opening. In particular, if the introduction element is designed as a lance, the through direction runs obliquely or preferably perpendicular to the axial direction of the respective swirl chamber or the respective outflow opening.
It is in particular conceivable that at least the inner swirl chamber is formed by a component in particular designed as a solid body, which also forms the atomizing lip and thus the end edge. In particular, a lateral surface of the component on the internal periphery delimits the inner swirl chamber outwards in the radial direction of the inner swirl chamber. The component, in particular its lateral surface on the internal periphery, is or functions for example as a prefilmer between the swirl chambers, and thus between the turbulent and thus swirled flows, also described as air flows. It is in particular conceivable that the lateral surface on the internal periphery or the prefilmer is formed by the previously specified dividing wall or that the component forms or has the previously specified dividing wall. By means of the introduction element, the fuel flowing through the exit opening and that has thus exited, in particular been injected, out of the injection element is applied to the prefilmer, in particular to the lateral surface on the internal periphery, in particular as a film also described as a fuel film or is atomized on the prefilmer between the two swirled air flows. Due to centrifugal forces resulting from the turbulent flow of the first part of the air, the fuel that has exited, in particular been injected, out of the introduction element, and has thus been introduced, in particular injected, i.e., sprayed, in particular directly into the inner swirl chamber, in particular as the previously specified film, is applied to the prefilmer, in particular to the lateral surface on the internal periphery, and flows or streams downstream to the first outflow opening, also described as a nozzle opening, and thus to the end edge. The fuel is thus applied to the atomizing lip and fed or transported to the end edge. According to the invention, the first outflow opening ends on the knife-sharp end edge, which has or provides only a small surface area due to the previously described tapering, such that no excessively large droplets of the fuel can form on the end edge. Due to the configuration according to the invention of the atomizing lip and in particular of the end edge, only tiny little droplets of the fuel break away on the end edge. In other words, only particularly small, i.e., tiny, droplets arise from the previously specified fuel film at the end edge, which break away on the end edge, in particular from the atomizing lip or from the component, and have a correspondingly large surface area. This effect leads to a particularly low-soot combustion of the mixture in the combustion chamber. Tiny droplets of the fuel can thus be generated even without high injection pressures of the fuel generated with significant effort and without high-cost injection elements, such that, on the one hand, the costs of the burner can be kept particularly low. On the other hand, particularly small droplets of the fuel can be generated, such that very low output of the burner can also be represented. The invention is in particular based on the knowledge that conventional burners have an excessively high pressure loss and are unsuitable for low outputs, and thus disadvantageous with regard to fuel consumption. The previously specified problems and disadvantages can now be avoided via the invention, such that in particular the fuel consumption can be kept low. Where the injection element is mentioned in the following, this should be understood to mean the introduction element.
Where the gas flowing through the exhaust gas tract is mentioned in the following, this should be understood to mean the previously specified exhaust gas of the internal combustion engine or the previously specified gas, if nothing else is specified. It is conceivable that the previously specified introduction point at which the burner exhaust gas is introduced into the exhaust gas tract or into the gas is arranged downstream or upstream of an oxidation catalyst, for example designed as a diesel oxidation catalyst, of the exhaust gas tract in the flow direction of the gas flowing through the exhaust gas tract. The oxidation catalyst is in particular designed to oxidize unburned hydrocarbons (HC) potentially contained in the exhaust gas and/or to oxidize carbon monoxides (CO) potentially contained in the exhaust gas, in particular into carbon dioxide.
To generate particularly small droplets of the fuel by means of the end edge, it is provided in an embodiment of the invention that the end edge is mechanically machined in a targeted manner. The feature that the end edge is in particular mechanically machined in a targeted manner should in particular be understood to mean that the end edge does not have a machined finish that can be formed in any way or provided in any way, and instead the end edge has been or is machined during production of the burner, in particular mechanically, in a targeted manner and thus as desired.
A further embodiment is characterized in that the end edge is rotated, i.e., machined while rotating, and/or is thus mechanically machined. Particularly small droplets of the fuel can thus be generated by means of the end edge.
In a further, particularly advantageous embodiment of the invention, it is provided that the turbulent flow of the first part of the air, in particular in the inner swirl chamber, is contrary to the turbulent flow of the second part, in particular in the outer swirl chamber. In other words, the swirl chambers are preferably designed to generate the turbulent flows of the parts of the air as turbulent flows that are contrary in relation to one another. Thus, for example, a first of the turbulent flows runs in a first rotation direction when viewed along the respective axial direction of the respective swirl chamber during a or the previously specified operation of the burner. In other words, the first turbulent flow for example has a first rotation direction when viewed in the axial direction of the respective swirl chamber. The second turbulent flow has a second rotation direction contrary to the first rotation direction when viewed in the axial direction of the respective swirl chamber. In other words, the second turbulent runs in a second rotation direction contrary to the first rotation direction when viewed in the axial direction of the respective swirl chamber A particularly advantageous mixture preparation can thus be obtained, such that the components can be quickly and efficiently (i.e., using little fuel) heated and/or kept warm.
To obtain a particularly advantageous mixture preparation, and thus a particularly efficient operation of the burner, it is provided in a further embodiment of the invention that the smallest flow cross-section of the second outflow opening that can be flowed through by the second part of the air is delimited or formed by the end edge inwards in the radial direction of the respective outflow opening and thus of the respective swirl chamber. In other words, the second outflow opening has its smallest flow cross-section on the end edge.
In a further, particularly advantageous embodiment of the invention, it is provided that the outer swirl chamber and thus the second outflow opening are formed by a component element in particular formed as one part, which can for example be formed separately from the previously specified component. It is in particular conceivable that the previously specified component, in particular formed as one part can be arranged in the component element. It is preferably provided that an anti-recirculation plate extends outwards from the component element in the radial direction of the respective outflow opening and thus of the respective swirl chamber, the anti-recirculation plate protruding outwards over at least a partial region of the component element in the radial direction of the respective outflow opening, and thus over the respective swirl chamber. It is conceivable that the partial region is arranged upstream of the anti-recirculation plate, i.e., on a rear side of the anti-recirculation plate, of which the rear side faces the respective swirl chamber. Thus, for example, at least a first region of the combustion chamber, in which, for example, the anti-recirculation plate is arranged, is at least partially divided from a second region of the combustion chamber by means of the anti-recirculation plate. It is in particular conceivable that the anti-recirculation plate extends completely continuously around the respective swirl chamber or around the respective outflow opening in the peripheral direction of the respective outflow opening, and thus of the respective swirl chamber, running around the respective axial direction of the respective outflow opening. By means of the anti-recirculation plate, it can be avoided, in particular after it exits the second outflow opening, that the mixture comprising the air and the fuel flows backwards into the combustion chamber, i.e., flows counter to the respective flow direction along which the parts and the fuel flow for example through the second outflow opening, such that an excessive vortex formation, in particular in the combustion chamber, can be avoided. For this purpose, it is preferably provided that the anti-recirculation plate runs in an imaginary plane that runs perpendicular to the respective flow direction and thus perpendicular to the respective axial direction of the respective outflow opening or of the respective swirl chamber. A particularly efficient operation of the burner can thus be obtained.
The prevent the mixture from flowing back into the combustion chamber excessively, and thus to avoid an excessive vortex formation in the combustion chamber, and thus to be able to obtain a particularly efficient operation of the burner, it is provided in a further embodiment of the invention that the second outflow opening ends in the flow direction of the parts of the air flowing through the second outflow opening and thus in the flow direction of the fuel flowing through the second outflow opening in a or in the previously specified imaginary plane running perpendicular to the flow direction of the parts of the air flowing through the second outflow opening. The anti-recirculation plate is thus not set back against the flow direction in relation to the second outflow opening, in particular in relation to its end, and instead, it is preferably provided that the second outflow opening, in particular its end, and the anti-recirculation plate lie in the shared imaginary plane, such that an excessive vortex formation can be safely avoided.
It has proved particularly advantageous if the anti-recirculation plate is formed as one part with the component element. An excessive vortex formation can thus be safely avoided, whereby the burner can be operated particularly efficient in a particularly cost-efficient manner.
It has finally proved particularly advantageous if the combustion chamber has several removal openings spaced apart from one another and separated from one another by respective wall regions preferably designed as solid bodies, wherein the wall regions are preferably formed as one part with one another. For example, the wall regions are formed by a perforated plate or perforated disc. Via the removal openings, the burner exhaust gas resulting from the combustion of the mixture can be removed from the combustion chamber, and thus introduced into the exhaust gas tract.
In the following, a start of the burner is described: During a cold start of the burner, there is still no high temperature and thus no high air movement in the respective swirl chamber. Usually, this state does not permit ignition, or this state at least makes an ignition more difficult. To obtain a particularly quick and effective start of the burner even when an internal combustion engine is running and/or in cold environmental conditions, the mixture should be able to be ignited, in particular in the combustion chamber, and thus be present as a mixture that can be ignited. This can be achieved by so-called pre-storage of fuel or of the fuel. For this purpose, for example, the fuel is first fed into the inner swirl chamber by means of a fuel pump and in particular fed, in particular injected into the inner swirl chamber via the injection element, and thus pre-stored, in particular for two to six seconds, i.e., during a period of time that is or can be pre-determined, which can for example lie in a range of two to six seconds inclusive, in particular while the ignition device remains deactivated, i.e., while an ignition spark ceases to be provided by the ignition device. Only afterwards, i.e., only after the period of time runs out, is the ignition device switched on, i.e., activated, and an actual air and fuel feed is started. In other words, it is for example preferably provided that the swirl chambers cease to be provided with air during the period of time. Due to this pre-storage, a particularly rich mixture forms, which, despite large droplets also offers a large fuel surface area suitable for ignition due to a particularly high mass.
An advantageous cooling of the ignition device for example designed as a spark plug can, for example, be obtained via perforated, in particular drilled ribs, in particular made of aluminium, which can, for example, be arranged or provided on a thread of the ignition device designed in particular as an outer thread and also described as an ignition spark thread. As an alternative or in addition, an in particular off-centre air feed, i.e., an at least substantially off-centre feed of the respective part of the air into the respective swirl chamber or into at least one of the swirl chambers can be provided. The previously specified fuel pump can be frequency-controlled and/or have a piston and a spring, such that exhaust gas cannot flow back. The use of a return valve can thus be avoided, and a particularly low dead volume can be created. In particular, it is conceivable that the prefilmer or the inner swirl chamber has a venturi nozzle, on or in the narrowest flow cross-section of which, for example, the injection element is arranged. The injection element, in particular the lance, can preferably have several, and in particular more than two, particularly small exit openings. The through direction for example forms a jet angle with the axial direction of the inner combustion chamber. In other words, for example, the fuel can flow through the exit opening while forming a fuel jet, and thus flow out of the injection element via the exit opening, wherein the fuel jet, in particular its longitudinal central axis, coincides with the through direction. By correspondingly selecting or adjusting the jet angle, a particularly advantageous mixture preparation can be produced. As an alternative or in addition, an afterburner or an afterburn function is conceivable, for example to generate a particularly high power and in particular a power of the burner greater than eight kilowatts. For example, the burner has a nominal power, which can be eight kilowatts, wherein an at least temporarily higher power of the burner can be provided compared to the nominal power. Particularly high temperatures of the gas, for example of at least or greater than 600 degrees Celsius, can thus also be obtained, such that, for example, the components designed in particular as particle filters can be heated to a particularly high temperature, for example of at least or greater than 600 degrees Celsius.
A third aspect of the invention relates to a motor vehicle preferably designed as a motor vehicle, in particular as a passenger car, which comprises a or the previously specified internal combustion engine for driving the motor vehicle. The motor vehicle additionally comprises one or the previously specified exhaust gas tract and at least one burner according to the first aspect of the invention. Advantages and advantageous embodiments of the first aspect of the invention should be seen as advantages and advantageous embodiments of the second aspect of the invention and vice versa.
Further advantages, features and details of the invention result from the following description of preferred exemplary embodiments and with reference to the drawings. The features and combinations of features specified previously in the description and the features and combinations of features specified in the following description of figures and/or shown in the figures alone can be used not only in the respectively specified combination, but also in other combinations or in isolation without leaving the scope of the invention.
Identical or functionally identical elements are provided with the same reference numerals in the figures.
The drive device 10 comprises an intake tract 24 that can be flowed through by fresh air, by means of which the fresh air flowing through the intake tract 24 is guided to and into the cylinder 16. The fresh air forms a mixture of fuel and air with the fuel, which mixture comprises the fresh air and the fuel, and is ignited and thus combusted in the respective cylinder 16 within the respective work cycle. The mixture of fuel and air is in particular ignited via self-ignition. Exhaust gas of the internal combustion engine 12, of which the exhaust gas is also described as engine exhaust gas, results from the ignition and combustion of the mixture of fuel and air.
The drive device 10 has an exhaust gas tract 26 that can be flowed through by the exhaust gas from the cylinders 16. The drive device 10 additionally comprises an exhaust gas turbocharger 28 that has a compressor 30 arranged in the intake tract 24 and a turbine 32 arranged in the exhaust gas tract 26. The exhaust gas can flow out of the cylinders 16, flow into the exhaust gas tract 26 and then flow through the exhaust gas tract 26. The turbine 32 can be driven by the exhaust gas flowing through the exhaust gas 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. Several components 36a-d are arranged in the exhaust gas tract 26, the components being designed as respective exhaust gas aftertreatment devices, i.e., exhaust gas aftertreatment components for aftertreating the exhaust gas. The components 36a-d are arranged following one after the other in the flow direction of the exhaust gas of the internal combustion engine 12 flowing through the exhaust gas tract 26, and are thus connected to one another in series or serially. For example, the component 36a is an oxidation catalyst, in particular a diesel oxidation catalyst (DOC). Furthermore, the component 36 can be a nitrogen oxide storage catalyst (NSK). The component 36b can be an SCR catalyst, which is also simply described as an SCR. The component 36c can be a particle filter, in particular a diesel particle filter (DPF). The component 36d can for example have a second SCR catalyst and/or an ammonia slip catalyst (ASC).
The motor vehicle has a structure for example designed as a self-supporting body that forms or delimits an interior of the motor vehicle also described as a passenger cell or safety cell. During a respective journey of the motor vehicle, people can be located in the interior. For example, the structure forms or delimits an engine compartment in which the internal combustion engine 12 is arranged. The exhaust gas turbocharger 28 is for example arranged in the engine compartment. The structure additionally has a base, also described as a main base, via which the interior is at least partially, in particular at least substantially or completely delimited downwards in the vertical direction of the vehicle. For example, the components 36a, b, c are arranged in the engine compartment, such that for example the components 36a, b and c form a so-called hot end or are components of a so-called hot end. The hot end can in particular be directly flange-mounted on the turbine 32. The component 36d is for example arranged outside of the engine compartment and underneath the base in the vertical direction of the vehicle, such that for example the component 36d forms a so-called cold end or is a component of the so-called cold end.
The drive device 10 comprises a dosing device 38, by means of which an in particular liquid reducing agent can be introduced into the exhaust gas tract 26 at an introduction point E1 and can for example be introduced into the exhaust gas flowing through the exhaust gas tract 26. The reducing agent is preferably an aqueous urea solution that can provide ammonia, which can react with nitrogen oxides potentially contained in the exhaust gas to form water and nitrogen in a selective catalytic reduction. The selective catalytic reduction can be catalytically caused and/or supported by the SCR catalyst. It can be seen from
The drive device 10 and thus the motor vehicle additionally comprise a burner 42 by means of which—as is explained in more detail in the following—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 gas tract 26 can be quickly and efficiently heated and/or kept warm. The burner 42 can combust a mixture, in particular while forming a flame 44, and in particular while providing a burner exhaust gas, wherein the burner exhaust gas or the flame 44 is or can be introduced into the exhaust gas tract 26 at an introduction point E2. This means that the burner 42 is arranged so to speak on the introduction point E2. In the exemplary embodiment described in
An air supply path 54 is further provided, via which or by means of which the burner can be or is provided with the air to form the mixture. This means that the air supply path 54 can be flowed through by the air from which the mixture is formed. A pump 56 also described as an air pump is arranged in the air supply path 54, by means of which pump the air can be fed through the air supply path 54 and can thus be fed to the burner 42. For example, the low-pressure pump 20 also described as a low-pressure fuel pump is described as a fuel pump, by means of which the fuel is fed through the fuel supply path 46 and thus to the burner 42.
It can be recognized that the air supply path 54 is fluidically connected to the intake tract 24 at a second connection point V2. Thus, for example, at least a part of the fresh air flowing through the intake tract 24 can be removed from the intake tract 24 at the connection point V2 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 to and in particular into the burner 42 by means of the air supply path 54. A second valve element 55 is arranged in the air supply path 54, by means of which second valve element the quantity of the air that is used to form the mixture and flows through the supply path 54 and thus flows through the burner 42 can be adjusted. For example, the control device is designed to control the valve element 55, such that for example the quantity of the air that is used to form the mixture and flows through the air supply path 54 and thus to be added to the burner 42 can be adjusted, in particular is to be controlled, by means of the control device via the valve element 55.
The burner 42 has an inner swirl chamber 62 that can be flowed through by a first part of the air that is added to the burner 42, and causes a turbulent first flow of the first part of the air. This should in particular be understood to mean that the first part of the air flows turbulently through at least one first partial region of the swirl chamber 62 and/or flows turbulently out of the swirl chamber 62 and/or flows turbulently into the combustion chamber 58. The inner swirl chamber 62 has in particular exactly one first outflow opening 64 that can be flowed through by the first part of the air along a first through direction of the outflow opening 64 and thus along a first flow direction coinciding with the first through direction. The first part of the air can be removed from the inner swirl chamber 62 via the first outflow opening 64. This means that the first part of the air can flow out of the inner swirl chamber 62 via the first outflow opening 64. The burner 42 further comprises an introduction element in the form of an injection element 66, which has a conduit 68 that can be flowed through by the liquid fuel that is added to the burner 42.
In the first embodiment, the injection element 66 is designed as a lance that is also described as a fuel lance. The conduit 68, and thus the injection element 66, has at least one exit opening 70 that can be flowed through by the liquid fuel flowing through the conduit 68. It can be seen from
The swirl chamber 62 is at least partially, in particular at least substantially and thus more than half or even completely formed or delimited by a preferably single-part component 74 preferably of the burner 42, such that the component 74 also forms or delimits the outflow opening 64.
The burner 42 further has an outer swirl chamber 76 that surrounds at least one longitudinal region and presently also the first outflow opening 64 in the peripheral direction of the swirl chamber 62, in particular completely continuously running around the axial direction of the swirl chamber 62. The component 74 has a dividing wall 78 that is arranged between the swirl chambers 62 and 76 in the radial direction of the swirl chamber 62 and the radial direction of which runs perpendicular to the axial direction of the swirl chamber 62. The swirl chambers 62 and 76 are thus separated from each other in the radial direction of the swirl chamber 65 by the dividing wall 78. The axial direction of the swirl chamber 62 coincides with the axial direction of the swirl chamber 76, such that the radial direction of the swirl chamber 62 coincides with the radial direction of the swirl chamber 76. The outer swirl chamber 76 can be flowed through by a second part of the air, which is added to the burner 42, and is designed to cause a turbulent second flow of the second part of the air. This means that the second part of the air flows turbulently through the swirl chamber 76 and/or flows turbulently out of the swirl chamber 76 and/or flows turbulently into the combustion chamber 58. In particular, it is preferably provided that the parts of the air have their turbulent flows in the combustion chamber 58, and thus run turbulently in the combustion chamber 58. The outer swirl chamber 76 has, in particular exactly, one second outflow opening 80 that can be flowed through, in particular along a third flow direction, by the second part of the air flowing through the outer swirl chamber 76, the third through direction of which second outflow opening, along which the outflow opening 80 can be flowed through by the second part of the air flowing through the swirl chamber 76, presently coincides with the axial direction of the swirl chamber 76, and thus with the axial direction of the swirl chamber 62. The third through direction coincides with a third flow direction, along which the second part of the air flowing through the outer swirl chamber 76 flows through or can flow through the outflow opening 80. This means in particular that the first through direction coincides with the third through direction and the first through direction coincides with the third flow direction, such that the first flow direction, the third flow direction, the first through direction and the third through direction presently coincide with the axial direction of the swirl chamber 62 and with the axial direction of the swirl chamber 76. The second outflow opening 80 is arranged downstream of the outflow opening 64 in the flow direction of the parts of the air, and in particular in series or serially with the outflow opening 64, such that the outflow opening 80 can be flowed through by the second part of the air, by the first part of the air and by the fuel. In particular, the first part of the air is in particular mixed with the fuel due to the turbulent first flow already in the swirl chamber 62, in particular while forming 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 turbulent second flow, whereby the mixture is particularly advantageously prepared, and thus the partial mixture is particularly advantageously mixed with the second part.
It can be seen that the swirl chamber 76 is at least partially, in particular at least substantially and thus at least more than half or even completely, delimited inwardly in the radial direction of the respective swirl chamber 62 or 76 by the component 74, in particular by the dividing wall 78. The swirl chamber 76 is at least partially, in particular at least substantially or completely, delimited by a component element 82, which is presently designed separately from the component 74, outwards in the radial direction of the respective swirl chamber 62 or 76. The component 74 is at least partially, in particular at least substantially, arranged in the component element 82. The outflow opening 80 is for example partially delimited or formed by the component element 82 and partially by the component 74, in particular with regard to the lowest or smallest flow cross-section of the outflow opening 80 that can be flowed through by the second part.
In order for at least the component 36b to be able to be heated and/or kept warm particularly efficiently, it is provided that—as can be seen particularly clearly from
The burner 42 further has an anti-recirculation plate 88, which, in the first embodiment, is arranged downstream of the outflow opening 80 and downstream of the component element 82 in the flow direction of the parts flowing through the outflow opening 80 and of the fuel flowing through the outflow opening 80. The anti-recirculation plate 88 has a 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 by the fuel from the swirl chambers 62 and 76. Starting from the through opening 90, and in particular starting from the outflow opening 80 and starting from the component element 82, in particular starting from its end, the anti-recirculation plate 88 extends outwards in the axial direction of the respective swirl chamber 62 or 76, whereby the anti-recirculation plate 88 protrudes outwards beyond at least a partial region T of the component element 82 in the radial direction of the respective swirl chamber 62 or 76. Thus, for example, a first part T1 of the combustion chamber 58 is at least partially separated from the 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 through opening 90 and into the combustion chamber 58, in particular into the part T2 back in the direction of the component element 82 or back into the part T1 can be avoided, such that an advantageous mixture preparation can be achieved.
It can further be seen from
As can be seen from
It is preferably provided that the nozzles, and thus the outflow openings 64 and 80, have the following sizes or surface ratios: The outflow opening 64 (inner nozzle) preferably has a diameter, in particular an inner diameter, which has 10 percent to 20 percent of Di. It is also preferably provided that the outer nozzle, and thus the outflow opening 80, has a diameter, in particular an inner diameter that is for example 10 percent to 35 percent of Da. An annular surface area should be coextensive from the inside to the outside, and thus both the inside and the outside should be 50 percent of the entire annular surface area. In other words, it is preferably provided that the air conduit LK1 has a first annular surface area and the air conduit LK2 has a second annular surface area, wherein the annular surface areas are preferably the same size.
The swirl generation apparatus 107 has an in particular central through opening 108, which is passed through by the injection element 66. In other words, the injection element 66 protrudes through the through opening 108 into the inner swirl chamber 62.
It is in particular conceivable that the opening cross-section 114 is an opening cross-section or exit cross-section, in particular of the combustion chamber 58, wherein the flame 44 or the burner exhaust gas can be removed from the combustion chamber 58 and introduced into the exhaust gas tract 26 via the exit cross-section. A tapering of the opening cross-section that is necessary, required or carried out to increase a flow velocity of the flame 44 or of the burner exhaust gas from the combustion chamber 58, in particular by corresponding movement of the closing elements 112 being implemented in the manner of an iris diaphragm should be represented in a manner favourable to flow. Thus, a conical outlet having an angle of 30 degrees to 70 degrees to the horizontal could be implemented instead of a hole in a flat closing plate, as is implemented, for example, by segments and/or by a cone in an aircraft engine. This can be implemented by a fixed geometry or variably, as in an aircraft engine having individual segments, the segments being foldable, for example in a thrust nozzle, or having a shiftably arranged exit cone that can for example be shifted in the axial direction of the respective swirl chamber 62 or 76.
As at least the longitudinal regions of the chamber parts 120 and 122 are arranged within one another, and are spaced apart from one another in the radial direction of the combustion chamber 58 while forming the clearance 124, wherein the clearance 124 is for example filled with air and thus designed as an air gap, a double wall of the combustion chamber 58 or of the chamber element 116 is created, whereby the combustion chamber 58 is insulated by the clearance 124, i.e., by the air gap. The combustion chamber 58 is thus insulated by air gap. In the following, reference is made in particular to the outer diameter Da shown in
Instead of the continuous removal opening 102, it is conceivable to use the several through openings 98 separated from one another and spaced apart from one another. In other words, it is conceivable that the removal opening 102 that is continuous per se and thus uninterrupted is divided into the several through openings 98 that are spaced apart from one another and separated from one another, the number of the through openings preferably lying in a range of 3 to 9 inclusive. The respective through opening 98 has a surface area, also described as an exit surface or through surface, wherein the sum of the surface areas of all of the through openings 98 is preferably the same as the exit surface of the continuous removal openings 102, i.e., the same as the surface area of the removal opening 102. The sum of the surface areas of the through openings 98 is also described as a total exit surface. The through openings 98 are for example designed as holes. It is conceivable that the sum of the surface areas of all of the through openings 98, i.e., the total exit surface, is 0.8 times to 1.8 times the surface area of the or of an uninterrupted, continuous removal opening of the removal opening 102 of the combustion chamber 58. It is in particular conceivable that the perforated disc 100 is arranged in the removal opening 102 or in the longitudinal region L1. With regard to the exhaust gas also described as engine exhaust gas, it can be advantageous for the internal combustion engine 12 to use a deflection element, in particular a deflection element and/or a perforated element, in particular a perforated sheet, wherein the perforated element can in particular be understood to mean an element formed as a solid body that has several holes spaced apart from one another and in particular separated from one another via respective walls, the holes being able to be flowed through by a gas, e.g., the burner exhaust gas or the engine exhaust gas. So that the engine exhaust gas does not excessively negatively influence and destabilize the flame 44 in the combustion chamber 58, for example, it is advantageous to provide a deflection element, e.g., a deflection sheet, in front of the combustion chamber 58, i.e., upstream of the combustion chamber 58, so that the engine exhaust gas cannot or can only slightly enter the combustion chamber 58, in particular against the flow direction, along which the flame 44 or the burner exhaust gas flows out of the combustion chamber 58 into the exhaust gas tract 26. It is thus preferably provided that the deflection element is arranged upstream of the combustion chamber 58, i.e., upstream of the introduction point E2, in the exhaust gas tract 26 in the flow direction of the engine exhaust gas. A geometry of the deflection element can depend on how the combustion chamber 58 is arranged in relation to the exhaust gas tract 26, i.e., in relation to an exhaust gas conduit of the exhaust gas tract 26. The exhaust gas conduit should be understood to mean that the burner exhaust gas or the flame 44 flows out of the combustion chamber 58, in particular along the fourth flow direction, into the exhaust gas conduit, in particular at the introduction point E2. An individual adjustment of the geometry of the deflection element is advantageous.
It is further advantageous, as previously described, that the closing device 110 or another closing device is arranged on the exit of the combustion chamber 58. This should in particular be understood to mean the following: The closing device 110 can for example be arranged in the longitudinal region L1 or in the removal opening 102, such that a flow cross-section, which can be flowed through by the burner exhaust gas or by the flame 44 and via which the burner exhaust gas or the flame 44 can be removed from the combustion chamber 58, in particular at the introduction point E2, and can be introduced into the exhaust gas tract 26, in particular into the exhaust gas conduit, is delimited by the closing device 110, in particular by the closing elements 112, and can consequently be varied, i.e., can be adjusted, by means of the closing device 110. The adjustable flow cross-section is in particular the opening cross-section 114.
The closing device 110 can be arranged in the chamber part 122 and in the removal opening 102, or the closing device 110 or another closing device is arranged downstream of the combustion chamber 58, i.e., downstream of the chamber part 122 and directly connected to the combustion chamber 58 or to the chamber part 122, and is thus arranged downstream of the removal opening 102 per se. A tapering of the removal opening 102, as is implemented in the fourth embodiment by the longitudinal region L1, i.e., by the cone described, leads to an increase of the flow velocity of the burner exhaust gas, wherein the tapering of the exit of the combustion chamber 58 should be depicted in a manner favourable to flow. The cone presently formed by the longitudinal region L1 preferably has an angle, also described as a cone angle, in particular to the axial direction of the combustion chamber 58, in particular depicted in
The further closing device can for example be a closing element depicted particularly schematically in
In the following, the previously specified air gap insulation of the combustion chamber 58 is explained in more detail: As the combustion chamber 58 becomes very hot on its outer wall and optionally glows, especially in its full power operation, the air gap insulation can guarantee a particularly safe operation. Heat loss can additionally be kept particularly low by the air gap insulation. It is preferably provided that an in particular thermal insulation surrounds the combustion chamber 58 in the peripheral direction running around the axial direction of the combustion chamber 58, in particular completely continuously. The air gap insulation, and thus the air gap, is provided as this insulation in the present case. The clearance 124 presently designed 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 the gap width, is preferably 6% to 25% of Da. It is in particular conceivable that the width lies in a range of 1.5 mm to 6 mm inclusive. It can in particular be seen that the chamber element 116 is a double-walled and thus air gap-insulated pipe. In other words, the chamber parts 120 and 122 form a double-walled and thus air gap-insulated pipe. It is preferably provided that an insulating element formed separately from the chamber element 116 (air gap-insulated pipe) surrounds the air gap-insulated pipe (chamber element 116), i.e., at least one longitudinal region of the chamber element 116 running in the axial direction of the combustion chamber 58, in the peripheral direction of the combustion chamber 58, in particular completely continuously. The insulation element is preferably an insulation mat. The insulation element is preferably formed at least from mineral wool and/or sheet metal, whereby the combustion chamber 58 can be particularly advantageously insulated.
In the following, a possible installation position of the combustion chamber 58 or of the burner 42 is described. As has previously been described, the mixture in the combustion chamber 58 is too thin to combust while releasing heat or heat energy. By means of the heat energy, at least the component 36b can for example be effectively and efficiently heated and/or kept warm. As an alternative or in addition, the component 36c for example designed as a particle filter can be heated. By heating the particle filter, a regeneration of the particle filter can for example be caused or carried out. So that the heat energy of the burner 42 can now be advantageously used, the latter or the introduction point E2 should be arranged as close as possible to the component to be heated or kept warm, such as for example the component 36b and/or 36c. Heat losses can thus also be kept low. To guarantee an advantageous mixing of the engine exhaust gas with the burner exhaust gas, however, a minimum distance to the mixing of the burner exhaust gas with the engine exhaust gas should be provided, wherein this minimum distance extends in particular in the flow direction of the engine exhaust gas flowing through the exhaust gas tract 26 from the burner 42 or from the introduction point E2, in particular continuously, to the component to be heated or to be kept warm, e.g., the component 36b, in particular to its entrance. In particular, the minimum distance is a minimum distance of the mixing chamber 40. The introduction point E2 thus cannot advance directly to the entrance of the component 36b. It has proved particularly advantageous if a spacing running in particular in the flow direction of the exhaust gas flowing through the exhaust gas tract 26 between the introduction point E2 and the component 36b immediately following the introduction point E2 in the flow direction of the exhaust gas tract 26 is at least 5 to 8 times Da and at most 30 times Da. The feature that the component 36b is immediately or directly connected to the introduction point E2 in the flow direction of the exhaust gas (engine exhaust gas) flowing through the exhaust gas tract 26 should be understood to mean that no other, further exhaust gas aftertreatment component is arranged in the flow direction of the exhaust gas flowing through the exhaust gas tract 26 between the introduction point E2 and the component 36b. As an alternative or in addition, a diameter, in particular an inner diameter, of the exhaust gas conduit in which the introduction point E2 is arranged should broaden conically to at least 6 times Da, in particular after it exits the combustion chamber 58, in particular before the exhaust gas enters the component 36b. In particular if the component 36b is a catalyst, in particular the previously specified SCR catalyst, the component 36b has a substrate. It is thus preferably provided that the previously specified spacing is a spacing running in particular in the flow direction of the exhaust gas flowing through the exhaust gas tract 26 between the introduction point E2 and the substrate of the catalyst. It is thus advantageous if the inner diameter of the exhaust gas conduit broadens to at least 6 times Da after exiting the combustion chamber 58, i.e., for example starting from the introduction point E2, before the exhaust gas (engine exhaust gas or burner exhaust gas) is applied to the substrate.
It can be seen from
To support the causation or generation of the turbulent 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 into the respective swirl chamber 62 or 76, but tangentially or obliquely to the respective axial direction of the respective swirl chamber 62 or 76, as is depicted in
To provide the burner 42 with the fuel, a fuel pump, e.g., a propellant pump, is used to feed the fuel from the tank 18. The fuel pump can thus for example be the low-pressure pump 20. It is advantageous to operate the burner 42 in a lambda-controlled manner, such that for example the mixture has a fuel-air ratio (y) of substantially at least 1.0. In other words, it is preferably provided that the burner is operated stoichiometrically, and the mixture is thus a stoichiometric mixture. In other words again, it is advantageously provided if a first portion of the air in the mixture and a second portion of the fuel in the mixture can be adjusted or regulated particularly precisely. It is advantageous if the first quantity of the air, also described as combustion air, of the mixture and a second quantity of the fuel of the mixture are at least substantially precisely adjusted and/or calculated and are introduced into the respective, corresponding swirl chamber 62 or 76. It is thus advantageous to use a frequency-controlled piston pump as the fuel pump for feeding the fuel to or into the burner 42. The frequency-controlled piston pump should be provided with a spring-loaded valve, e.g., a ball valve, on its exit, to prevent fuel or exhaust gas from flowing back, in particular into the fuel pump.
Such a fuel pump is shown in
The lateral surface 86 on the internal periphery of the component 74 is also described as a film wall, as the fuel that is injected out of the injection element 66 via the exit openings 70 and is applied or injected against the film wall forms the previously specified film or fuel film on the film wall (lateral surface 86 on the internal periphery). To apply the fuel particularly advantageously on or against the film wall, a simple lance, e.g., the injection element 66 shown in
In a block 182, a comparison in which an actual value of the temperature T5 is compared with a target value of the temperature T5 is implemented. The actual value of the temperature T5 is for example the previously specified T5 value, and/or for example the actual value of the temperature T5 is measured, in particular by means of the previously specified temperature sensor, in particular at the introduction point E2 or at a point in the exhaust gas tract 26 arranged downstream of the introduction point E2, and in particular upstream of the component 36b. If, for example, the comparison yields that the actual value is less than or equal to the target value, then a state adjusted in particular in the block 174 is maintained, in particular with regard to the operation of the fuel pump and the air pump, wherein the fuel pump is depicted in
In a block 192, the quantity of the air of the mixture is determined, in particular measured, in particular via an air flow measurement. It is additionally depicted via an arrow 194 that the quantity of the fuel is determined, in particular measured. In a block 196, the fuel-air ratio (y) is determined, in particular calculated, depending on the determined, in particular measured quantity of the air and depending on the determined, in particular measured or calculated quantity of the fuel. In particular, in the block 196, an actual value of the fuel-air ratio of the mixture is determined, in particular calculated. In a block 198, the actual value of the fuel-air ratio is compared with a second target value of the fuel-air ratio, wherein the second target value is for example 1.03. If the actual value of the fuel-air ratio corresponds to the target value of the fuel-air ratio, or if the actual value of the fuel-air ratio deviates from the target value of the fuel-air ratio only such that a difference between the actual value of the fuel-air ratio and the target value of the fuel-air ratio is in particular larger in magnitude or equal to a limit, then a current operation of the burner 42, in particular of the fuel pump and of the air pump is maintained. If, however, the actual value of the fuel-air ratio deviates excessively from the target value of the fuel-air ratio, then, as depicted in particular by an arrow 200, the air pump and/or the fuel pump is changed with regard to its respective operation, in particular by controlling the fuel pump or the air pump, in particular such that the difference between the actual value of the fuel-air ratio and the target value of the fuel-air ratio is at least reduced or even eliminated.
Finally, a block 202 depicts that the target value of the temperature T5 is predetermined by or from the control device, in particular in the block 182. As an alternative or in addition, the control device can predetermine or emit the target value of the fuel-air ratio, in particular in the block 198.
The swirl generation apparatus 107 comprises an inner first swirl generation device 115 that comprises the first inner swirl generation elements 94. In the exemplary embodiment shown in
The swirl generation apparatus 107 comprises the swirl generation device 115 that has the swirl generation elements 94 and is arranged in the air conduit LK1 and an outer, second swirl generation device 117 that has the second, outer swirl generation elements 96 and is arranged in the air conduit LK2. The swirl generation elements 96 are thus arranged in the air conduit LK2, wherein the swirl generation elements 96 are arranged one after the other, and in particular spaced apart from one another in the peripheral direction of the respective swirl chamber 62 or 76, and thus in the peripheral direction of the swirl generation apparatus 107. By means of the swirl generation elements 96, i.e., by means of the swirl generation device 117, the part of the air flowing through the air conduit LK2 is diverted, deflected or guided such that the second turbulent flow of the second part of the air is caused. The respective swirl generation element 96 is preferably formed as one part with the wall 109 and/or 111 and/or as one part with the body 113 and/or as one part with the respective swirl generation element 94, such that the swirl generation apparatus 107 is preferably formed as one part in total. In the exemplary embodiment shown in
The respective air conduit LK1 or LK2 per se, i.e., when considering the respective air conduit LK1 or LK2 without the swirl generation elements 94 or 96, has a surface area also described as a passage cross-section, in particular upstream of the respective swirl generation device 115 or 117 and/or downstream of the respective swirl generation device 115 or 117. As the respective air conduit LK1 or LK2 per se is presently annular in shape, the respective surface area is a respective surface area of a ring surface. It is preferably provided that the respective swirl generation elements 94 or 96 cover or block at least 20 percent and at most 60 percent of the surface area of the respective air conduit LK1 or LK2 per se arranged upstream and/or downstream of the respective swirl generation device 115 or 117, whereby a particularly advantageous swirl generation can be obtained. The body 113, which is a central body, is closed, and thus cannot be flowed through by air. The body 113 per se is additionally formed rotationally symmetrically with regard to its longitudinal axis or longitudinal central axis, which coincides with the axial direction of the respective swirl chamber 62 or 76, and thus with the axial direction of the swirl generation apparatus 107. In particular, the body 113 is presently designed as an in particular central and/or closed profile.
The respective swirl generation element 94 or 96 forms for example the angle β with the previously specified imaginary plane EB, the angle preferably lying in a range of 10 degrees to 45 degrees inclusive. It is further preferably provided that the respective swirl generation element 94 or 96 causes a deflection of the respective part of the air flowing through the respective air conduit LK1 or LK2 by a deflection angle that preferably lies in the range of 70 degrees to 90 degrees inclusive.
To obtain a particularly advantageous mixture formation, it is preferably provided that the swirl generation device 115, in particular the swirl generation elements 94, runs or is designed contrary to the swirl generation device 117, in particular the swirl generation elements 96, such that the first turbulent flow of the first part of the air has a first direction of rotation, in particular around the respective axial direction of the respective swirl chamber 62 or 76, wherein the second turbulent flow of the second part of the air preferably has a second direction of rotation, in particular around the axial direction of the respective swirl chamber 62 or 76, and wherein the first direction of rotation is contrary to the second direction of rotation or vice versa.
It can be seen from
According to
It can in particular be seen that the air chamber 92 is a supply chamber shared by the two swirl chambers 62 and 76 and also described as an air supply chamber, which is explained in more detail in the following.
It can be seen from
A first direction contrary to the flow direction depicted by the arrow 246 and running in parallel with the respective axial direction of the respective swirl chamber 62 or 76 or coinciding with the respective axial direction of the respective swirl chamber 62 or 76 is depicted in
Finally,
In the embodiment in
In the exemplary embodiment shown in
The injection element 66 has a valve seat 272 that is presently, in particular directly, formed by the introduction element housing 254, in particular by the housing part 266. The valve element 256 has a seat surface 274 corresponding to the valve seat 272, the seat surface also being described as a sealing surface and presently being formed, in particular directly, by the valve 256. In the blocked position, the valve element 256 sits via its seat surface 274, in particular directly, on the corresponding valve seat 272, such that the seat surface 274 touches the corresponding valve seat 272, in particular directly. In the exemplary embodiment shown in
When viewed for example in combination with
If the burner 42 is inactive and the internal combustion engine 12 is running, the valve element 56 is in the blocked position, such that no gas, e.g., motor exhaust gas or burner exhaust gas, in particular from the combustion chamber 58, and dirt particles contained therein can penetrate the exit opening 60 and thus reach the fuel supply path 46, which could lead to deposits there, and consequently to throttle losses in the fuel dosing, such that a particularly advantageous mixture preparation can be guaranteed even over a particularly long lifespan of the burner 42.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2021 001 580.0 | Mar 2021 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/057444 | 3/22/2022 | WO |
