EP3289193A1

EP3289193A1 - Exhaust-gas aftertreatment system for an internal combustion engine, internal combustion engine having an exhaust-gas aftertreatment system, and use of an air flow nozzle

Info

Publication number: EP3289193A1
Application number: EP16717840.9A
Authority: EP
Inventors: Marc Hehle; Olaf SCHÄFER-WELSEN; Claudia Riedel
Original assignee: MTU Friedrichshafen GmbH
Current assignee: Rolls Royce Solutions GmbH
Priority date: 2015-04-30
Filing date: 2016-04-21
Publication date: 2018-03-07
Also published as: US10473017B2; CN107580650B; DE102015208016A1; US20180149060A1; HK1249569A1; CN107580650A; WO2016173700A1

Abstract

The invention relates to an exhaust-gas aftertreatment system (3) for an internal combustion engine (1), comprising a catalyst device (5), which is designed to catalytically reacting at least one exhaust-gas component with a reactant, and comprising a reactant-metering device (7), which is arranged upstream of the catalyst device (5) along a flow path of the exhaust gas through the exhaust-gas aftertreatment system (3). According to the invention, the reactant-metering device (7) has at least one exhaust-gas flow nozzle (9).

Description

DESCRIPTION

Exhaust after-treatment system for an internal combustion engine, internal combustion engine with an exhaust aftertreatment system and use of a Luftstromdüse

The invention relates to an exhaust aftertreatment system for an internal combustion engine, an internal combustion engine with such an exhaust aftertreatment system, and a use of a Luftstromdüse.

In exhaust gas aftertreatment systems for internal combustion engines having a catalyst device which is adapted for the catalytic conversion of at least one

Exhaust gas component with a reactant, the requirement arises that the

Reactant must be metered into a flow path of the exhaust gas. For this purpose, a reactant metering device is typically upstream along a flow path of the exhaust gas through the exhaust aftertreatment system

Catalyst device arranged. For an efficient conversion of the exhaust gas component with the reactant at the catalyst device, it is necessary for the reactant to be intimately mixed with the exhaust gas, preferably vaporized, and if appropriate reacted chemically to a component which then ultimately reacts on the catalyst device. For this purpose, especially in the large engine area usually long dosing and

Mixture preparation sections necessary, which increases the space required for the exhaust aftertreatment system. If a turbine, for example from an exhaust-gas turbocharger, is provided in the exhaust-gas aftertreatment system, this can be used as a mixer by arranging the reagent-metering device upstream of the turbine. This shortens the mixing section considerably. It turns out, however, that the

Reactant metering device typically must work against the exhaust pressure upstream of the catalyst device and in particular upstream of the turbine, in particular in the latter case, a pressure of about 5 to 6 bar can prevail in an exhaust pipe into which the reagent is to be metered. If a pressure atomizer is used, it requires a reactant admission pressure of at least 10 bar, preferably more than 10 bar, in order to ensure a quality of atomization sufficient for the preparation of the reaction mixture with regard to an efficient reaction at the catalyst device. In this case, the drop across a Druckzerstäuberdüse falling pressure difference to produce a certain atomization quality depends quadratically on the flow of reaction medium through the Druckzerstäuberdüse, ie from a desired metering. This results in the need for a high dynamic range for the form of the Druckzerstäuberdüse. The extent required in particular, high pressures can be achieved only with relatively high cost, which is also associated with high costs. Incidentally, pressure atomizers typically produce a comparatively coarse spray, that is, in particular comparatively large reactant droplets, so that long residence times in the exhaust aftertreatment system are required for mixture preparation in order to completely evaporate the reaction agent and to intimately mix it with the exhaust gas. There are also known atomizer nozzles which generate a spray by means of compressed air. This means a high technical effort to provide compressed air in the form of pressure vessels and / or by means of a compressor.

The invention is based on the object, an exhaust aftertreatment system, a

Internal combustion engine and a use of a Luftstromdüse to create, said disadvantages do not occur.

The object is achieved by providing the subject matters of the independent claims. Advantageous embodiments emerge from the subclaims.

The object is achieved in particular by providing an exhaust gas aftertreatment system for an internal combustion engine which has a catalyst device which is set up for the catalytic conversion of at least one exhaust gas component with a reactant. The exhaust aftertreatment system further includes a reactant metering device disposed along a flow path of the exhaust through the exhaust aftertreatment system upstream of the catalyst device. The

Exhaust gas aftertreatment system is characterized in that the reagent metering device has at least one exhaust gas flow nozzle. An "exhaust stream nozzle" is understood to mean an atomizer device which is designed as an exhaust-gas-based atomizer device, wherein it is in particular designed to atomize the reaction medium, in particular exclusively, by means of the exhaust gas flow along the flow path.

In particular, the exhaust gas flow nozzle is designed to-preferably exclusively-use aerodynamic forces of the exhaust gas flow, in particular shearing forces, for atomizing the reaction medium. On a compressed gas source that is set up to support the Sputtering process, in particular a compressed air tank and / or a compressor, is preferably omitted; The reagent metering device therefore preferably has no

Compressed gas source, which is adapted to assist the sputtering process, or is free of such a compressed gas source. The exhaust aftertreatment system has advantages over the prior art. In particular, it is possible with a Abgasstromdüse to produce a very fine spray, in particular small droplet size, so that a

Mixing section upstream of the catalyst device - especially due to short

Evaporation times of the spray - can be reduced. This reduces the space requirement of the exhaust aftertreatment system. Furthermore, the functionality of a

Abgasstromdüse that the reactant is sheared and thereby atomized substantially by aerodynamic forces of the exhaust gas flowing in the exhaust pipe, in which the reagent metering device is arranged, and thereby. In any case, the atomization effect is essentially not based on a drop across the exhaust stream nozzle

Pressure difference for the reagent, but rather on the in the exhaust pipe

acting, aerodynamic forces and in particular on the shear effect. Therefore, it is not necessary in an exhaust gas flow nozzle to provide such a high pressure difference as is necessary in a pressure atomizer. For example, the falling across the Abgasstromdüse differential pressure can be reduced to about 1 bar, because it only serves the Nachförderung of reagent and not its atomization. It is also largely possible, the falling over the exhaust stream nozzle pressure difference or the

Form pressure of the reaction agent upstream of the exhaust stream nozzle largely independent of the desired metered amount, thus the mass or volume flow of reactant via the Abgasstromdüse to keep. The spray quality is largely independent of the dosage. The exhaust gas aftertreatment system can therefore be much less complex, simpler and less expensive to implement and more cost-effective.

In particular, conventional pumps can be used to deliver the reactant. Furthermore, pressure sources such as compressed air tanks or compressors for

Support for the atomization process omitted. The term "exhaust gas component" here and in the following designates a chemical substance which is comprised by the exhaust gas of the internal combustion engine and which is catalytically reacted at the catalytic converter device, although it may or may not necessarily be a chemical substance combustion occurs in the internal combustion engine.

Rather, it can also be a chemical that burns during combustion not or not fully implemented. For example, it may be at the

Exhaust gas component to nitrogen oxides or act on oxygen.

The term "reaction agent" is understood to mean a reagent which is fed to the exhaust gas stream downstream of the combustion and which itself reacts with the exhaust gas component at the

Catalyst device is reacted, or which represents a precursor component, which is reacted upstream of the catalyst device in the exhaust gas stream, wherein a product of this reaction ultimately reacts at the catalyst device with the exhaust gas component. The reaction agent may be, for example, a reducing agent, in particular urea, ammonia - optionally as a liquid gas - or a urea-water solution, or a hydrocarbon. In this respect, the term "reaction with a reaction agent" is also understood as meaning a catalytic conversion of the at least one exhaust gas component with a product formed from the reactant, in particular ammonia If the exhaust gas component is oxygen, and the reactant is preferably a hydrocarbon, which on the oxidation catalyst with the oxygen as

Exhaust gas component is oxidized.

Particularly preferred is an embodiment of the exhaust aftertreatment system in which the catalyst device is designed as a catalyst for the selective catalytic reduction of nitrogen oxides (SCR catalyst). In this case, the exhaust gas component is a nitrogen oxide or a mixture of nitrogen oxides, in particular nitrogen dioxide and / or

Nitrogen monoxide, wherein the reactant is a reducing agent, in particular a

Urea-water solution, is.

The exhaust gas flow nozzle is preferably designed as an exhaust-flow-driven airflow nozzle, in particular as an exhaust-gas-driven Airblast atomizer, or has at least one such airflow nozzle, in particular such an Airblast atomizer. Airflow nozzles are commonly known in aircraft engine manufacturing as atomizers for fuel. Such

Air flow nozzle has at least one film layer on which a liquid film can be applied. The liquid film is shear-tension driven to a shear edge of the film layer

transportable, where by aerodynamic shear forces one at the film layer flowing past or the film depositor flowing around the gas mass flow, here the exhaust stream, is atomized. In this case, the aerodynamic gas forces shear the thin liquid film at the shear edge of the film layer, which typically initially produces larger droplets that move relatively slowly with the gas stream. These drops also work in the

Gas flow continues to have aerodynamic shear forces, resulting in secondary decay and ultimately very fine atomization. In such a Luftstromdüse results in a very high dynamic range in the dosing with constant spray properties.

An embodiment of the exhaust aftertreatment system is preferred, which is characterized in that a turbine is provided upstream of the catalyst device, preferably the turbine of a turbocharger. The reagent metering device is preferably arranged upstream of the turbine. It is then possible to use the turbine as a mixer, which further significantly shortens the mixing distance for the reactant.

The reagent metering device is preferably close, more preferably as close as possible, to the turbine. In this case, the high flow velocities, which act close to an inlet of the turbine, have a particularly favorable effect on the atomization properties of the exhaust gas flow nozzle. In this area also act particularly high

aerodynamic forces, which are also favorable for the atomization properties of

Exhaust stream nozzle are. In contrast, the relatively high pressure in the exhaust pipe in this area does not have a negative effect, since the Abgasstromdüse not on a high

Reactant overpressure is relied upon for efficient atomization of the reactant. An embodiment of the exhaust aftertreatment system is preferred, which is characterized in that the reagent metering device in or on a

Inlet section of the turbine is arranged or integrated in the inlet section. In this way it is possible to arrange the reagent metering device particularly close to the turbine. Particularly preferably, the reagent metering device is formed integrally with the turbine. The turbine and the reagent dosing device can thus be handled and installed as a component, which is logistically particularly favorable and associated with the least possible effort and low costs. An exemplary embodiment of the exhaust aftertreatment system is preferred, which is characterized in that the reagent metering device is arranged in an exhaust pipe of the exhaust aftertreatment system, preferably upstream of a turbine. In particular, an exemplary embodiment is preferred in which the reagent-metering device in which an exhaust manifold or exhaust manifold, preferably

upstream of a turbine.

An exemplary embodiment of the exhaust gas aftertreatment system is preferred, which is characterized in that the exhaust gas flow nozzle has at least one film layer. The film applicator preferably circumferentially concentrically surrounds a main flow direction of the exhaust gas in a line section of the exhaust aftertreatment system. The film applicator is preferably-preferably at its upstream end-fluid-connected to a concentrically encircling annular channel for supplying reactant. The annular channel can also be arranged in a different position relative to the Filmeleger, for example - in the main flow direction - centered on this. In particular, it is possible for the film applicator to be quasi tubular or tubular-section-shaped, wherein it is preferably arranged concentrically in the line section. The film applicator and / or the line section can / preferably be conical. The annular channel is preferably arranged at the upstream end of the film layer, so that the

Flow direction of the reaction agent on the film former of the main flow direction of the exhaust gas in the line section corresponds. Thus, in addition to promoting the reactant along the film former, the exhaust gas flow may also contribute to its shear edge. At the shear edge of the film layer, the reactant is sheared off by the aerodynamic forces of the exhaust stream. The here proposed embodiment of the filmmaker, his

Fasteners and leads is particularly straightforward and easy to manufacture, in particular by simple assembly or in a generative manufacturing process, such as 3D printing. It is still inexpensive.

The fact that the film-maker circumferentially surrounds a main flow direction of the exhaust gas in the line section of the exhaust aftertreatment system concentric surrounds, in particular means that the film applicator surrounds a radially inner region of the line section and / or itself, the in operation of the exhaust aftertreatment system of Exhaust gas is flowed through. The film applicator preferably has a radially outer region, which is surrounded by exhaust gas during operation of the exhaust gas aftertreatment system. The exhaust gas flows during this process in particular by the radially inner region encompassed by the film applicator, wherein it simultaneously flows around the film applicator in the radially outer region. The filmmaker encompasses

in particular on the one hand, a central recess through which exhaust gas can flow, wherein it is preferably arranged to the other at a radial distance from an inner wall of the line section and in particular held.

The film applicator is preferably held by at least one web in the line section, wherein the at least one web is preferably fixed on the one hand to a wall of the line section and on the other hand to the annular channel, wherein the film-laying itself is in turn arranged on the annular channel. In particular, the annular channel preferably carries the film layer.

Preferably, the at least one web is also adapted to supply the annular channel with reactant, wherein it has a through hole which the annular channel

in particular connects to a supply line outside the Leirungsabschnitts.

Particularly preferred is a plurality of webs are provided, which hold the film-laying and the annular channel concentric in the line section, and which are preferably arranged at equal angular intervals to one another, ie rotationally symmetrical about the film-laying and the annular channel. In particular, an embodiment with three webs is preferred.

It is possible that each web has a through hole for reactants. The annular channel is preferably divided into a plurality of separate chambers, in particular three chambers, wherein preferably each of the chambers is in each case one of the webs in

Fluid connection is. In this way, a separate supply of the chambers of the

Ring channel may be provided with reagent over the webs. This facilitates a dosage of the reagent.

Particularly preferably, the reactant supply lines formed in this way are designed to be switchable, in particular integrated upstream of the webs or into the webs

controllable valve devices are provided, through which the leading via the webs to the annular channel fluid paths are obvious and closable. In this way, a very simple adjustment of a dosage of the reagent can take place.

It is possible for a swirl-generating means, in particular a swirling grid, to be arranged on the film-depositor and / or on the annular channel, in order to supply the exhaust-gas stream which surrounds the film-depositor flows around and flows through the film depositor to impart a spin. This increases the efficiency of atomization by the exhaust stream nozzle.

It is also an embodiment of the exhaust aftertreatment system possible, in which at least one planar film layers - especially in the form of a flat wing - the

Abgasstromdüse is arranged in a line section of the exhaust aftertreatment system. Preferably, the at least one planar film depositor is arranged centrally in the conduit section. An exemplary embodiment of the exhaust gas aftertreatment system is also preferred, which is characterized in that the reagent metering device has a plurality of

Exhaust gas guide elements, which are in particular - seen in the circumferential direction - spaced from one another at a swirl generating device for the exhaust gas, wherein at least one of the exhaust guide is designed as a film applicator. The

Swirl generating device is preferably configured to deflect the exhaust area radially. Here, under an axial direction in particular a

Main flow direction of the exhaust gas along a line section of the

Exhaust after-treatment system, in which the reagent dosing device is arranged, understood, wherein a radial direction is perpendicular to the axial direction. A

The circumferential direction concentrically surrounds the axial direction. The exhaust gas guide elements are preferably designed to impart a swirl to the exhaust gas flowing around it radially or flowing radially between them.

Preferably, a plurality of the exhaust gas guide elements, particularly preferably all

Exhaust elements, designed as a film applicator. In that regard, in particular, a

Embodiment of the exhaust aftertreatment system preferred, which is characterized in that the reagent metering device comprises a plurality of film layers, which in particular as - seen in the circumferential direction - spaced from each other

Exhaust gas guide elements are arranged on a swirl generating device for the exhaust gas.

In a preferred embodiment, the conduit portion has a constriction formed by a mounting plate extending radially inwardly from an inner wall of the conduit portion, the mounting plate having a central recess through which exhaust gas can flow. The exhaust gas guide elements and / or film layers are preferably arranged on the mounting plate, wherein a baffle plate is disposed on the exhaust guide elements and / or film layers turn - spaced by the exhaust guide elements and / or film layer in the axial direction of the mounting plate. The baffle plate forms an upstream end of the swirl generating device, wherein the mounting plate a

forms the downstream end of the swirl generating device. From upstream

inflowing exhaust gas is passed through the baffle plate radially outward, and flows between the exhaust guide elements and / or film makers through to the recess, where it is again deflected in the axial direction and continues to flow axially through the recess of the mounting plate. The exhaust gas guide elements and / or film layers act as guide vanes, which offset the radially flowing between them exhaust gas a twist. For this purpose, they preferably have a suitable, aerodynamic geometry.

The baffle plate preferably has a convex or cambered front side facing the oncoming exhaust gas, which in a particularly efficient manner directs the exhaust gas flowing in radially outward. The front side can also be flat. At a downstream end surface on which the film layers are arranged, the baffle plate preferably has one

Strömungsleitgeometrie, preferably a central dome or bead, which is centrally located and so far concentrically surrounded by the film makers. These

Strömungsleitgeometrie serves for an efficient deflection of the exhaust gas, which flows in between the film layers, in the axial direction and thus a passage of the exhaust gas through the recess in the mounting plate. However, the Strömungsleitgeometrie can also be in any other form, in particular convex, concave, or as a bore, in particular as a through hole through which exhaust gas can flow, be formed. In the mounting plate, at least one annular groove is preferably arranged to supply the film layers with reactant. Preferably, the mounting plate has at least two, in particular exactly two, separate annular grooves, wherein different film layers, in particular directly adjacent film layers, are in fluid communication with different annular grooves. The supply lines for the reaction medium formed via the annular grooves are preferably switchable, particularly preferably adjustable, controllable and / or controllable with respect to their flow cross-section; in particular, each annular groove is preferably assigned a controllable valve.

It is possible that at the upstream end of the baffle an additional

Swirl generating means is arranged, which in addition to the oncoming exhaust gas Swirl mediates. This may for example have a plurality of guide vanes, which are arranged on the end face.

By the film-makers serve as exhaust elements of a swirl-generating device, the atomization can be particularly efficient, because the swirl-containing exhaust generates particularly high aerodynamic shear forces on the film makers. Furthermore, it is possible that detached from a film depositor, larger drops impact on a - seen in the circumferential direction - adjacent film layers and form there another liquid film, which in turn is atomized by shear forces of the exhaust stream.

It is also an embodiment of the exhaust aftertreatment system is preferred in which at least one film layer, preferably a plurality of film layers, on a

Circumferential wall of a line section is / are arranged, preferably between likewise also arranged on the peripheral wall vanes, which impart a swirl the exhaust gas flow and / or deflect it radially. The vanes heated by the exhaust gas contribute to the fact that the reactant atomized at the shearing edges of the film layers evaporates particularly quickly.

In a preferred embodiment of the exhaust aftertreatment system

provided that the at least one film layer can be tempered, in particular cooled, is. It is particularly possible that the at least one film layer with a cooling line

fluidly connected, via which the film-maker a cooling medium can be fed. Alternatively or additionally, cooling of the at least one film layerer also occurs

thermoelectric element, for example a Peltier element, or in another suitable manner. Cooling the film layerer has the advantage of being typically

heat-sensitive reactants can be stabilized on the film seter so that it does not age, disintegrate or decompose prematurely. It is also possible that the at least one

Filmleger - electrically or by applying a heating medium - is heated. This can be advantageous in particular in a starting phase of an internal combustion engine in order to quickly reach a target temperature at the shear edge of the film layer. By tempering the

Filmleger the shearing edge in a predetermined target temperature range - preferably controlled or regulated - durable. Preferably, additionally or alternatively, at least one of the guide vanes is temperature-controllable, in particular coolable.

An exemplary embodiment of the exhaust aftertreatment system is also preferred, which is characterized in that the reagent metering device has at least one supply line for reactants to the at least one film former, wherein the at least one supply line is preferably switchable. In particular, a switchable or controllable valve is preferably arranged in the supply line, through which the supply line for the

Reactant can be blocked and released. Preferably, a variably controllable valve is provided, by means of which - in particular controlled or regulated - a variable control of a reagent flow through the supply line can be realized. Preferably, the

Reactant metering device on a plurality of leads to a plurality of film layers, wherein each feeder is preferably associated with a supply line. It is possible that a plurality of filers a common lead is assigned. In particular, it is possible that at least two groups of filers exist, with different groups of filers being assigned different leads. The different

Feed lines are preferably switchable or controllable separately, wherein they particularly preferably have separately switchable or controllable valves. About the supply line and in particular via a switchable or controllable supply line, it is particularly simple and preferably at the same time sensitively possible, a the exhaust gas

To influence to be metered amount of reactant, in particular to control or regulate.

An embodiment of the exhaust aftertreatment system is also preferred, which is characterized in that the reagent metering device at least one

Agitator means adapted to impart a spin through the exhaust gas metering means or around the reactant metering means. These may be, for example, a swirl lattice, vanes, baffles or other suitable elements. The swirl generating means is preferably arranged at an upstream end of the reagent metering device, so that the exhaust gas already passes through the reactant metering device with swirl. This allows the quality of atomization through the exhaust stream while optimizing

Total pressure loss can be further improved. There is also preferred an embodiment of the exhaust aftertreatment system, which is characterized by a purging device, which is adapted for purging the at least one supply line. The purging device preferably has a fluid connection, which is set up for connecting the supply line to a compressed air source, in particular a charge air line of an internal combustion engine, preferably downstream of a compressor, or with another source of compressed air or compressed gas for purging, and at the same time for disconnecting the supply line from a reaction medium -Reservoir. By means of the purging device, the at least one supply line - in particular before its deactivation - emptied, so that a thermal damage, in particular a decomposition of arranged in the supply line reactant can be avoided.

The object is also achieved by providing an internal combustion engine having an exhaust aftertreatment system according to one of the previously described embodiments. In particular, the advantages that have already been explained in connection with the exhaust gas aftertreatment system are realized in connection with the internal combustion engine.

Particularly preferred is an embodiment of an internal combustion engine having an exhaust gas turbocharger, wherein in the exhaust aftertreatment system, a turbine of the turbocharger is arranged. The turbine is preferably upstream of the

Catalyst device of the exhaust aftertreatment system arranged, the

Reagent metering device preferably upstream of the turbine, in particular close to the turbine, preferably as close as possible to the turbine and more preferably arranged in or at an inlet portion of the turbine or integrated into the inlet portion. An embodiment of the internal combustion engine is also preferred in which the

Reactant metering device is integrally formed with the turbine. This results in both particularly favorable sputtering qualities as well as a particularly short mixing distance for the reactant. The internal combustion engine is preferably designed as a reciprocating engine. In a preferred embodiment, the internal combustion engine is used to drive in particular heavy land or water vehicles, such as mine vehicles, trains, the internal combustion engine is used in a locomotive or a railcar, or ships. Also a use of the internal combustion engine to drive one of the defense Serving vehicle, such as a tank, is possible. An exemplary embodiment of the internal combustion engine is preferably also stationary, for example, for stationary

Energy supply used in emergency power, continuous load operation or peak load operation, the internal combustion engine in this case preferably drives a generator. A stationary application of the internal combustion engine for driving auxiliary equipment, such as fire pumps on oil rigs, is possible. Furthermore, an application of the

Internal combustion engine in the field of promotion of fossil raw materials and in particular fuels, for example oil and / or gas possible. It is also possible to use the internal combustion engine in the industrial sector or in the field of construction, for example in a construction or construction machine, for example in a crane or an excavator. The

Internal combustion engine is preferably designed as a diesel engine, as a gasoline engine, as a gas engine for operation with natural gas, biogas, special gas or other suitable gas.

In particular, when the Bremkraftmaschine is designed as a gas engine, it is suitable for use in a cogeneration plant for stationary power generation.

It is an embodiment of the exhaust aftertreatment system or the

Internal combustion engine is preferred in which it is provided that the catalyst device is set up as a catalyst for the selective catalytic reduction of nitrogen oxides (SCR catalyst). The reagent dosing device is preferably configured for dosing a reducing agent, in particular a urea-water solution, in the exhaust gas stream of the exhaust aftertreatment system.

The object is also finally achieved by providing a use of a Luftstromdüse, wherein the Luftstromdüse in a reagent metering device or as a reagent metering device for an exhaust aftertreatment system, in particular for an exhaust aftertreatment system according to one of the embodiments described above, in particular as Abgasstromdüse is used. The use of an air flow nozzle as the reagent metering device or in a reagent metering device and in particular as an exhaust gas flow nozzle achieves, in particular, the advantages already known in US Pat

Connection with the exhaust aftertreatment system and / or the internal combustion engine have been explained.

Preferably, a designed as an airblast atomizer Luftstromdüse is used, or a Luftstromdüse having at least one Airblast atomizer. The invention will be explained in more detail below with reference to the drawing. Showing:

Figure 1 is a detail view of an embodiment of an internal combustion engine with an exhaust aftertreatment system;

Figure 2 shows various detail views of a first embodiment of a

Exhaust aftertreatment system;

Figure 3 shows various detail views of a second embodiment of a

Exhaust aftertreatment system, and

Figure 4 is a detail view of a third embodiment of a

Aftertreatment system.

1 shows a detailed sectional view of an exemplary embodiment of an internal combustion engine 1, which has an exhaust gas aftertreatment system 3. This has a here only schematically indicated atalysatoreinrichtung 5, which is adapted for the catalytic conversion of at least one exhaust gas component with a reagent. It is the

Catalyst device 5 here preferably as a catalyst for selective catalytic reduction of nitrogen oxides (SCR catalyst) is formed, wherein as the exhaust gas component nitrogen oxides, in particular nitrogen monoxide or nitrogen dioxide, with a reducing agent,

in particular with released from a urea-water solution ammonia, as

Reactants are reacted on the catalyst.

Along a flow path of the exhaust gas through the exhaust aftertreatment system 3 seen upstream of the catalyst device 5, a reagent dosing device 7 is arranged, which has at least one, here exactly one exhaust stream 9. It is possible by means of the exhaust stream 9, to produce a very fine spray without a high

Differential pressure above the exhaust flow nozzle 9 must be formed. The Abgasstromdüse is therefore very efficient and at the same time simple and inexpensive to deploy.

The exemplary embodiment of the internal combustion engine 1 shown here has a turbocharger 11, wherein a turbine 13 of the turbocharger 11 is arranged in the exhaust gas aftertreatment system 3 upstream of the catalyst device 5. The reagent metering device 7 is in turn arranged upstream of the turbine 13. The turbine 13 drives via a shaft to a compressor 15, which in a non-illustrated Charging path of the internal combustion engine 1 for the compression of combustion air or a

Combustion air-fuel mixture is provided.

Here, the exhaust gas flow nozzle 9 is arranged in particular in an inlet section 17 of the turbine 13, it being possible for it to be integrated into the inlet section 17 and / or formed integrally with the turbine 13.

Exhaust gas flows from combustion chambers of the internal combustion engine into an exhaust gas collector 19, which may be designed as an exhaust manifold. From the exhaust manifold 19, the exhaust gas passes through the inlet portion 17 and thus also via the reagent metering device 7 in the turbine 13 and from this in turn to the catalyst device 5. From the Katalylsatoreinrichtung 5 from the exhaust gas flows further, it being possible that at least another

Exhaust after-treatment component of the exhaust aftertreatment system 3 is included, or that the exhaust gas flows directly to an outlet of the exhaust aftertreatment system 3, in particular to an exhaust of the internal combustion engine 1. It is also possible that at least one further upstream of the catalyst device 5 shown here

Exhaust after-treatment component is provided.

The turbine 13 serves as part of a mixing section for thorough mixing of the

Reactant with the exhaust gas. Since such a mixing in the turbine 13 is very efficient, the length of the mixing section can be significantly reduced overall. At the same time, it can be seen that a high flow velocity prevails in the inlet section 17 of the turbine 13, so that high aerodynamic shear forces occur on the reagent metering device 7, which promote efficient spray formation with very good spray properties.

Fig. 2 shows in several detail views a first embodiment of

Exhaust after-treatment system 3, in particular a first embodiment of the Reaktionsmitteldosiereinrichtung 7, and in particular the embodiment, which is also shown in Figure 1. The same and functionally identical elements are provided with the same reference numerals, so that reference is made to the preceding description. The

According to FIG. 2 a), the exhaust gas flow nozzle 9 has a film layer 21, which, in the exemplary embodiment shown here, revolves concentrically about a main flow direction of the exhaust gas represented by an arrow P in a line section 23 of the exhaust gas aftertreatment section formed here by the reagent metering device 7. Systems 3 is arranged. During the operation of the internal combustion engine 1, the exhaust gas flows through a radially inner region encompassed by the film feeder 21, wherein it simultaneously flows around the film applicator 21 in a radially outer region. Namely, the film applicator 21 engages on the one hand a central recess 25, through which exhaust gas can flow, wherein it is arranged at a radial distance from an inner wall 27 of the line section 23 in this and in particular held.

The film applicator 21 is in fluid communication at its upstream end with a concentrically encircling annular channel 29 for supplying reactant. It is provided in particular that the annular channel 29 carries the film applicator 21.

The annular channel 29 is in turn here of three - in the circumferential direction - with the same angular distance from each other, so in particular rotationally symmetrical, arranged webs 31 held in its central position in the line section 23, each of the webs 31 here has a through hole 33, which is used to supply the Ring channel 29 is used with reagent. The annular channel 29 is preferably divided into three separate chambers, wherein each of the webs 31 is associated with a chamber. The chambers are fluidly separated from each other, so that each chamber can be supplied separately via its associated web 31 with reagent.

In that regard, supply lines 35 are provided for reactants to the at least one film layer 21, which comprise the through-holes 33. At least one of the supply lines 35 is preferably switchable. Particularly preferably, each of the supply lines 35 is formed switchable. A switchable supply line 35 - preferably each switchable supply line 35 - preferably has a controllable valve, through which the supply line 35 can be blocked and released. Particularly preferably, a change in a flow cross section of the switchable supply line 35 is possible, in particular continuous. This is then designed in particular controllable or regulated. In this way, a very simple dosage of

Reaction agent possible. In particular, each of the three chambers of the annular channel 29 may preferably be supplied separately with reactants, or a supply line to the chamber may also be blocked.

Fig. 2b) shows a schematic sectional view through the reagent metering device 7 according to Figure 2a). Here, in particular, the film applicator 21, the annular channel 29, one of Webs 31 and formed in the web 31 through hole 33 and thus also the supply line 35 recognizable. With the letter D is a detail section referred to, which is explained in more detail in Figure 2c). Fig. 2c) shows the detail D of Figure 2b) in an enlarged view. Identical and functionally identical elements are provided with the same reference numerals, so that reference is made to the preceding description. It turns out that the film applicator 21 is inserted here in the annular channel 29, wherein he is in particular with a tongue 37 in the

Ring channel 29 extends into and held there, preferably clamped. It is also possible that the tongue 37 is merely an orientation of the film layer 21 relative to the

Ring channel 29 is used. In any case, it is possible that the film applicator 21 additionally or alternatively positively, frictionally, materially and / or connected by suitable connection means with the annular channel 29 and in particular is attached to this, so that the annular channel 29 carries the film applicator 21. The tongue 37 is preferably provided at predetermined positions - seen in the circumferential direction - with holes, so that the reaction medium through the webs 31 in an interior 39 of the annular channel 29, in particular in chambers of the annular channel 29, can flow. Preferably, three holes in the tongue 37 are provided, which in mounted

Condition with the through holes 33 are aligned. It is also possible to have one

Filmleger 21 with annular channel 29 and optionally with its fasteners and leads in one piece in a generative manufacturing process, for example, by 3 D printing to produce.

In the illustrated embodiment remains in the assembled state between the annular channel 29 and the film applicator 21 on an inner side, which faces an imaginary central axis of the main flow direction of the exhaust gas, a gap 41 through which

Reactant on a film laying surface 43 of the film layer 21 can flow out. On this film laying surface 43, the reaction medium reaches a shearing edge 45 of the film applicator 21, which is shown in FIG. 2b). Here the reaction agent is sheared off and atomized by the aerodynamic forces of the exhaust gas. Alternatively or in addition to the gap 41, a row or an array of holes is / are also possible.

The gap 41 is formed radially inward here. Additionally or alternatively, it is also possible that the gap 41 is formed radially outward, so that the film laying surface 43 is formed as an outer surface of the film layer 21. 3 shows a plurality of detailed representations of a second exemplary embodiment of the exhaust gas aftertreatment system 3 and in particular of a second embodiment of a reagent metering device 7. Identical and functionally identical elements are provided with the same reference numerals, so that reference is made to the preceding description.

It can be seen in particular in FIGS. 3 a) and 3c) that the reagent metering device 7 has a plurality of film layers 21 which are arranged as exhaust gas guide elements spaced apart from each other at a swirl generator 47 for the exhaust gas. The swirl generating device 47 is configured to redirect the exhaust area radially. The film layers 21 are arranged to impart a twist to the exhaust gas flowing radially between them. In particular, the film layers are designed as guide vanes for the exhaust gas. In the embodiment of the reagent metering device 7 shown here, the line section 23 has a constriction 49, which is formed by a mounting plate 51 projecting radially inwards from the inner wall 27, which has a central recess 53. The film layers 21 are arranged here between the mounting plate 51 and a baffle plate 55, wherein the film layer 21 are in particular supported by the mounting plate 51, wherein the film layer 21 in turn carry the baffle 55. The baffle plate 55 has a the inflowing exhaust gas flow facing, here convex, in particular cambered, designed end face 57 on. At one of the end face 57 and thus the oncoming exhaust gas

facing away from the end surface, the baffle plate 55 has a central bead 59, which serves a second deflection of the exhaust gas, this time in the axial direction.

Oncoming exhaust gas is directed radially outward through the cambered baffle plate 55, where it is then radially deflected by the constriction 49 and flows between the film layers 21, which impart a swirl to the exhaust gas. Supported by the bead 59, the exhaust gas is in turn deflected in the axial direction and flows through the recess 53. The film layers 21 serve as guide vanes for the exhaust gas.

FIG. 3 b) shows an enlarged view of a film applicator 21. It can be seen that each of the film applicators 21 here preferably has a gap 41 for supplying the film laying surface 43 with reaction agent, in which case a pressure counter surface 61 of the film applicator 21 Filmlegefläche 43 is formed. Alternatively or additionally, it is possible that a pressure surface 63 of the film applicator 21 is formed as a film laying surface 43, wherein then in the pressure surface 63, a gap 41 is provided. It is also possible that not every one of them

Exhaust elements is designed as a film applicator. The gap 41 is not provided in a not designed as a film depositor exhaust guide. Alternatively or in addition to the gap 41, a row or an array of holes is / are also possible.

Fig. 3c) shows a schematic plan view of the assembly of the baffle plate 55 with the film makers 21. The same and functionally identical elements are provided with the same reference numerals, so that reference is made to the preceding description. Here, in particular, the following is shown: If the pressure counter-surface 61 is used as a film laying surface 43, in particular larger drops of the reaction agent, which are detached from the shear edge 45, impact an opposite pressure surface 63 of an adjacent film layer 21 and wet them. In this way, the opposite pressure surface 63 in turn acts as a film laying surface, wherein the thus impacted drops turn on the

Shearing edge 45 - and this time finer - are atomized. In this way, the

Sprayeigenschaften the exhaust stream 9 are still improved.

Fig. 3d) shows a further view of the second embodiment of the reagent metering device 7. The same and functionally identical elements are provided with the same reference numerals, so reference is made in this regard to the preceding description. In this case, two supply lines 35 for reactants can be seen here. These are fluidly connected to two fluidically separated grooves 65 disposed in the mounting plate 51, each of the grooves 65 supplying a certain number or group of film layers 21 with reaction medium. In this case, immediately adjacent film layers 21 are supplied by different grooves 65 with reagent. In this case, each of the grooves 65 supplies four film layers of reactants from the total of eight film layers present here. The supply is - as already indicated - seen in the circumferential direction - alternately through the various grooves 65th

Fig. 3e) shows a schematic representation of a modification of the second

Embodiment of the reagent metering device 7. Here, on the end face 57 of the baffle plate 55 a swirl generating means 67 is arranged with a plurality of guide vanes, of which here for the sake of clarity, only one with the Reference numeral 69 is designated. The guide vanes 69 cause a particularly efficient deflection of the exhaust gas radially outward in the region of the end face 57 and also impart a swirl to the exhaust gas before it flows into the swirl generating device 47 and receives a twist through the film layers 21.

Fig. 4 shows a schematic representation of a third embodiment of a

Exhaust aftertreatment system 3 and in particular a reagent metering device 7. The same and functionally identical elements are provided with the same reference numerals, so reference is made to the preceding description. Here, too, the reactant metering device 7 has a plurality of film layers 21, which also as - seen in the circumferential direction - spaced exhaust gas guide elements on a

Swirl generating means 47 are arranged for the exhaust gas, wherein the

Swirl generating device 47 is arranged to divert the exhaust gas radially in regions, and wherein the film layer 21 are arranged to impart a twist to the exhaust gas flowing radially between them. Here, however, the film layers 21 are arranged, preferably fixed, on the inner wall 27, which is an inner circumferential wall of the pipe section 23, the film layers 21 being arranged between guide blades 69. The film layers 21 are themselves also embodied as guide vanes, although here the guide vanes 69 arranged between the film layers are preferably made larger than the film layers 21.

The film layers 21 are preferably supplied with reactant via a wall 71 of the line section 23.

Overall, it turns out that using the exhaust aftertreatment system 3 and the

Internal combustion engine and in particular by means of the exhaust gas flow nozzle 9 formed

Reactant metering device 7 a very efficient, reliable atomization of a reagent with relatively little effort and can be realized in a cost effective manner.

Claims

1. exhaust aftertreatment system (3) for an internal combustion engine (1), with

- A catalyst device (5) which is adapted for the catalytic conversion of at least one exhaust gas component with a reactant, and with a

- along a flow path of the exhaust gas through the exhaust aftertreatment system (3) seen upstream of the catalyst device (5) arranged reagent metering device (7), characterized in that

- The reagent-metering device (7) has at least one Abgasstromdüse (9).

2. exhaust aftertreatment system (3) according to claim 1, characterized by an upstream of the catalyst device (5) arranged turbine (13), preferably a turbocharger (11), wherein the reagent metering device (7) upstream of the turbine (13) is arranged ,

3. exhaust aftertreatment system (3) according to any one of the preceding claims, characterized in that the reagent-metering device (7) in or on a

Inlet portion (17) of the turbine (13) arranged or integrated in the inlet portion (17), or that the reagent metering device (7) in an exhaust pipe, in a

Exhaust manifold or exhaust manifold is arranged.

4. exhaust aftertreatment system (3) according to any one of the preceding claims, characterized in that the Abgasstromdüse (9) has at least one film applicator (21), preferably - circumferentially concentrically around a

Main flow direction of the exhaust gas in a line section (21) of the

Exhaust after-treatment system (3) is arranged, wherein the film former (21) is fluidly connected to a concentrically encircling annular channel (29) for supplying reactant.

5. exhaust gas aftertreatment system (3) according to any one of the preceding claims, characterized in that the reagent-metering device (7) has a plurality of

Exhaust gas guide elements, which - seen in the circumferential direction - spaced from each other at a swirl generating means (47) are arranged for the exhaust gas, wherein the

Swirl generating device (47) is arranged to divert the exhaust area radially, wherein the exhaust gas guide elements are preferably arranged to impart a swirl to the exhaust gas flowing around radially, and wherein at least one of

Exhaust gas guide is designed as a film applicator (21).

6. exhaust gas aftertreatment system (3) according to any one of the preceding claims, characterized in that the reagent-metering device (7) has a supply line (35) for reactant to the at least one film applicator (21), wherein the at least one supply line (35) preferably switchable, in particular controllable or adjustable, is.

7. exhaust aftertreatment system (3) according to any one of the preceding claims, characterized in that the reagent-metering device (7) at least one

having heatable, in particular coolable and / or heated, film-laying (21).

8. exhaust aftertreatment system (3) according to any one of the preceding claims, characterized in that the exhaust aftertreatment system (3) comprises a purging device which is adapted for purging the at least one supply line.

9. exhaust aftertreatment system (3) according to any one of the preceding claims, characterized in that the reagent-metering device (7) at least one

Agitator means (67) arranged to impart a twist to the exhaust gas.

10. internal combustion engine (1), characterized by an exhaust aftertreatment system (3) according to one of claims 1 to 9.

11. Internal combustion engine (1) according to claim 10, characterized in that the

Internal combustion engine (1) has a turbocharger (11).

12 exhaust gas aftertreatment system (3) or internal combustion engine (1) according to any one of the preceding claims, characterized in that the catalyst device (5) is designed as a catalyst for the selective catalytic reduction of nitrogen oxides.

13. Use of an airflow nozzle (9) in a reagent metering device (7) or as a reagent metering device (7) for an exhaust gas aftertreatment system (3), in particular for an exhaust aftertreatment system (3) according to one of claims 1 to 9.