AT521241A1 - Arrangement and method for operating an internal combustion engine with an exhaust aftertreatment system - Google Patents

Abstract

The invention relates to an arrangement (100) of an internal combustion engine (1) having an exhaust aftertreatment system (2), comprising at least one component (3) and a gas channel arrangement (4), and a preheating device (5), wherein the preheating device (5) for preheating the at least one disposed in the gas channel assembly component (3) of the exhaust aftertreatment system (2), in particular at fired and / or unbefeuerter internal combustion engine (1) is arranged, wherein the preheating device (5) has a heating element (6) and a conveyor device (7) for generating a heated gas stream flowing through the exhaust aftertreatment system (2), wherein a channel (8) which bypasses at least one component (3) is provided, in which the preheating device (5) is arranged. Furthermore, the invention relates to a method for operating an internal combustion engine (1) with an exhaust aftertreatment system (2) and a preheater (5).

Description

Summary

The invention relates to an arrangement (100) of an internal combustion engine (1) with an exhaust gas aftertreatment system (2), comprising at least one component (3) and a gas channel arrangement (4), and a preheating device (5), the preheating device (5) for preheating the at least one component (3) arranged in the gas duct arrangement

Exhaust gas aftertreatment system (2), in particular in the case of a fired and / or unfired internal combustion engine (1), the preheating device (5) comprising a heating element (6) and a conveying device (7) for generating a heated gas stream flowing through the exhaust gas aftertreatment system (2) , At least one component (3) bypassing channel (8) is provided, in which the preheating device (5) is arranged.

The invention further relates to a method for operating an internal combustion engine (1) with an exhaust gas aftertreatment system (2) and a preheating device (5).

Fig. 1

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Arrangement and method for operating an internal combustion engine with an exhaust gas aftertreatment system

The invention relates to an arrangement of an internal combustion engine with an exhaust gas aftertreatment system, comprising at least one component and a gas duct arrangement, and a preheating device, the preheating device being set up for preheating the at least one component of the exhaust gas aftertreatment system arranged in the gas duct arrangement, in particular with a fired and / or unfired internal combustion engine , wherein the preheating device comprises a heating element and a conveying device for generating a heated gas stream flowing through the exhaust gas aftertreatment system.

The invention further relates to a method for operating an internal combustion engine with an exhaust gas aftertreatment system and a preheating device.

It is a known problem in exhaust gas aftertreatment systems of internal combustion engines that the components of the exhaust gas aftertreatment systems can only develop their full effectiveness from a certain operating temperature. For this reason, a large proportion of the pollutants emitted occurs in modern, almost pollutant-free internal combustion engines when the exhaust gas aftertreatment system is not at operating temperature. For this reason, there is a demand for arrangements in which the components of the exhaust gas aftertreatment system can be preheated.

In hybrid drives in particular, in which the vehicle is temporarily driven exclusively by the electric motor, both the internal combustion engine and its exhaust gas aftertreatment system cool down temporarily, as a result of which increased emissions are emitted.

To solve this problem, attempts have so far been made to electrically heat the base bodies of the catalytic converters of the vehicles from the outside. However, it is primarily necessary to bring the surface of the catalyst which comes into contact with the gas stream to operating temperature. Due to the indirect heating via the basic body of the catalytic converter, the heating of conventional devices is inefficient and sluggish.

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Another problem with hybrid vehicles is that not only the exhaust gas aftertreatment system but also the internal combustion engine itself cools down. For this reason, it is known in hybrid vehicles to provide electrical heaters that are used to preheat the intake air. To preheat the combustion chambers, this preheated intake air is pumped into the combustion chambers of the internal combustion engine by dragging the internal combustion engine, which heats them up. If necessary, this air is also pumped further through the exhaust gas aftertreatment system. However, the engine block has a relatively high heat capacity, with which a large part of the thermal energy is absorbed by the engine block or the combustion chamber walls. Efficient heating of the exhaust gas aftertreatment system is not possible with this method.

The object of the invention is to provide an arrangement which enables efficient preheating of at least one component of an exhaust gas aftertreatment system.

Another aim is to provide a method by which at least one component of an exhaust gas aftertreatment system can be heated efficiently.

The object is achieved in that, in an arrangement of the type mentioned at the beginning, an at least one bypass duct is provided, in which the preheating device is arranged.

An advantage achieved in this way can be seen in particular in that the combination of the heating element and the conveying device and their arrangement in a separate channel means that the at least one exhaust gas aftertreatment component can be heated particularly effectively.

The at least one component bypass duct is designed as a bypass duct of the gas duct arrangement, wherein in the gas duct arrangement in particular several components of the exhaust gas aftertreatment system are preferably arranged in the flow direction in a single exhaust duct. The duct bypasses the component or components that are to be heated. If two or more exhaust gas aftertreatment components are to be heated, it can advantageously be provided that the duct bypasses all of these components. The one or more components of the exhaust gas aftertreatment arrangement are arranged in the gas duct arrangement. In principle, the gas channel arrangement can also

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Exhaust gas treatment system are arranged. It can be provided that the channel bypasses one or more components which are arranged in one, two or more exhaust gas channels.

Part of the exhaust gas conveyed by the gas duct arrangement is branched off through the duct. The branch takes place downstream of the component to be heated, upstream of which the gas stream heated by the preheating device is returned to the gas channel arrangement. The direction of flow and arrangement can also be reversed, especially when the internal combustion engine is stopped. As a result, heat is transported into the component to be heated, more precisely into a sub-volume thereof. The channel in particular has a low specific heat capacity and is advantageously designed to be as short as possible, so that the element to be heated can be heated up in a short time. Furthermore, the channel can advantageously be heat-insulated. This ensures a very efficient heat input into the component, which subsequently results in a maximum conversion of the pollutant components such as nitrogen oxides.

Several components are advantageously arranged in the gas channel arrangement of the exhaust gas aftertreatment system of the arrangement according to the invention. For example, the following components can be arranged downstream of the engine in the flow direction: an oxidation catalytic converter (DOC or LNT or PNA), a catalytic converter, in particular for selective catalytic reduction (SCR catalytic converter), a particle filter (SDPF) and another catalytic converter, in particular for selective catalytic reduction ( SCR catalyst). The internal combustion engine is designed in particular as a diesel internal combustion engine, which is why the elements are preferably designed and arranged for a diesel engine. However, it can also be favorable if the internal combustion engine has a gasoline or gas engine with corresponding exhaust gas aftertreatment components. The channel is arranged and designed in particular to bypass the first catalytic converter, which is designed, for example, for selective catalytic reduction. That is, the duct branches off from the gas duct arrangement downstream of the first catalytic converter, and part of the exhaust gas is conveyed through the duct with the aid of the conveying device, where it is heated by the heating element. Upstream of the first catalyst is the

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Elements of the preheater can also be reversed.

In the context of the invention, the conveying device is designed in particular as a blower, but can also be any other type of conveying device. The heating device can be an electrical or electrically operated heating device, for example. In principle, two or more heating devices can also be provided. In the context of the invention, the gas stream is understood to be a gas, in particular either exhaust gas or air or an exhaust gas / air mixture, which is gaseous.

It can be advantageous if the conveying device is a separate conveying device which can be operated independently of the normal operation of the internal combustion engine or which is deactivated in the normal operation of the internal combustion engine. In principle, it is advantageous if the conveying device is a blower or a high-performance blower. It is also advantageously provided that the delivery device can also be operated with low engine mass flows.

It can also be advantageous if the conveying device is a separate compressor, a separate blower, a separate compressor or a separate pump. This ensures that a predefined and / or determinable amount of gas can be branched off from the gas channel arrangement via the channel and can be returned to the gas channel arrangement via the channel.

It can also be favorable if the conveying device and the heating element are designed as an integral component. This means that the branched-off gas is conveyed through the channel by a single element and heated therein. For this purpose, the conveying device can be designed, for example, as a blower with an electrical heating element. So a number of the required elements is reduced.

Alternatively, it can be expedient if the heating element is arranged downstream or upstream of the conveying device. When the heating element is arranged downstream of the conveying device in the channel, part of the exhaust gas flows first through the conveying device and then through the heating element in the flow direction. In principle, however, it can also be favorable if the

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Conveying device is arranged downstream of the heating element, a part of the gas in the channel then flowing in the flow direction first through the heating element and then through the conveying device.

It is advantageous if at least one first reducing agent injector is provided for introducing a reducing agent into the gas channel arrangement, the channel opening into the gas channel arrangement upstream of the reducing agent injector. The reducing agent injector is for introducing a reducing agent such as Formed and arranged urea or urea solution, which is upstream of the component.

The bypass can be designed and arranged for any exhaust gas aftertreatment component or the combination of several exhaust gas aftertreatment components.

The further aim is achieved if, in a method of the type mentioned at the outset, a gas flow heated by at least one heating element of the preheating device arranged in at least one component is conveyed through the exhaust gas aftertreatment system using a conveying device via a gas duct arrangement.

The advantages and effects achieved in this way correspond to the advantages and effects mentioned above, which are described in connection with the arrangement according to the invention, which is why a new description and list is dispensed with.

The invention and its mode of operation are further described below using method steps. If the arrangement, in particular the internal combustion engine and the exhaust gas aftertreatment system, has been operated for a certain period of time in such a way that the exhaust gas aftertreatment system has a temperature at which it cannot work optimally, this can be detected, for example, by a temperature sensor. If it now appears on the basis of different parameters that the internal combustion engine will shortly return to its fired operation, or that the exhaust gas aftertreatment system should shortly become effective, the preheating device is activated. Optionally or alternatively, however, it can also be provided that the preheating device is always in operation when the

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Temperature of the exhaust gas aftertreatment system is below a certain threshold.

If the preheating device is activated, a heating element is activated in any case, which heats the gas conveyed through the gas channel arrangement. This heated gas is subsequently conveyed through the exhaust gas aftertreatment system and in particular through those components of the exhaust gas aftertreatment system that are to be preheated. For this purpose, a conveyor device is preferably activated. This conveying device can be, for example, a conveying device of the internal combustion engine or a separate conveying device.

In particular, the conveying device is a blower, a compressor or a pump, through which a gas can be conveyed through the gas channel arrangement. This gas is preferably ambient air and / or exhaust gas which is drawn in and conveyed through the exhaust gas aftertreatment system and heated via a heating element. The conveyor and the heating element are arranged in a channel that bypasses the component to be heated.

If the necessary operating temperature has been reached, which in turn can be determined, for example, using a temperature sensor, in particular a real or modeled temperature sensor, the preheating device can optionally be deactivated. For example, modeled sensors can be used in which a temperature model is stored in which other values for determining the temperature, e.g. the power consumption, the heat input into engine or exhaust gas aftertreatment components or similar values.

In hybrid vehicles, for example, preheating occurs after a longer drive phase, in which only the electric motor is active and the internal combustion engine is towed inactive or at least unfired. The preheating of the components of the exhaust gas aftertreatment system may also be necessary before and / or during a cold start, in particular if the vehicle or the internal combustion engine is started again after a certain time in which the internal combustion engine has not been operated.

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It is advantageous if the gas flow in the course of the gas channel arrangement after

Internal combustion engine, that is to say on the exhaust gas side, is heated by the preheating device, in particular by the heating element of the preheating device.

It can also be advantageous if the heated gas flow is conveyed upstream or downstream of the component of the exhaust gas aftertreatment system to be heated from the duct into the gas duct arrangement.

Further advantages, features and effects result from the exemplary embodiment shown below. In the drawings, to which reference is made, shows:

Fig. 1 shows an inventive arrangement of an internal combustion engine.

1 shows an arrangement 100 according to the invention of an internal combustion engine 1 with an exhaust gas aftertreatment system 2. The exhaust gas aftertreatment system 2 comprises a component 3 and a gas duct arrangement 4, the component 3 being arranged in the gas duct arrangement 4.

A duct 8 bypassing component 3 is provided, in which a preheating device 5 is arranged. The preheating device 5 is designed to preheat the component 3, the component 3 being designed as an SCR catalytic converter in this exemplary embodiment.

The preheating device 5 is set up to preheat the component 3 arranged in the gas channel arrangement 4 when the internal combustion engine 1 is fired and / or unfired. This comprises a heating element 6 and a conveyor device 7, the heating element 6 being arranged in the channel 8 downstream of the conveyor device 7. However, the arrangement can also be reversed, the heating element 6 then being arranged in the channel 8 upstream of the conveying device 7.

In addition, an example of an oxidation catalytic converter 10, an SDPF 11 and a further SCR catalytic converter 12 are arranged in the gas channel arrangement 4, the oxidation catalytic converter 10 upstream of the first SCR catalytic converter 4 and the SDPF 11 and the further SCR catalytic converter 12 downstream of the first SCR catalytic converter. Catalyst 4 are arranged. It is also a

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Reducing agent injector 9 for introducing a urea into the

Gas channel arrangement 4 is provided, the channel 8 upstream of the

Reducing agent injector 9 opens into the gas channel arrangement 4 and heated

Introduces gas flow into this, more precisely in the SCR catalyst 3.

However, the gas duct arrangement can also comprise any other exhaust gas aftertreatment components and is not restricted to a diesel-specific arrangement.

The arrangement 100 further comprises the following components:

Combustion chamber 13, charge air cooler 14, turbocharger 15, 20, EGR cooler 16, intake-side gas channel 17, throttle valve 18, return channel 19, exhaust-side gas channel 21, exhaust 22, further injector 32.

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Claims (13)

claims 1. Arrangement (100) of an internal combustion engine (1) with an exhaust gas aftertreatment system (2), comprising at least one component (3) and a gas channel arrangement (4), and a preheating device (5), the preheating device (5) for preheating the at least one Component (3) of the exhaust gas aftertreatment system (2) arranged in the gas duct arrangement, in particular in the case of a fired and / or unfired internal combustion engine (1), is set up, the preheating device (5) being a heating element (6) and a conveying device (7) for generating a Exhaust gas treatment system (2) flowing through heated gas stream, characterized in that an at least one component (3) bypassing channel (8) is provided, in which the preheating device (5) is arranged. 2. Arrangement (100) according to claim 1, characterized in that the conveying device (7) is a separate conveying device (7) which can be operated independently of the control mode of the internal combustion engine (1) or which is deactivated in the control mode of the internal combustion engine (1). 3. Arrangement (100) according to claim 1 or 2, characterized in that the conveying device (7) is a separate compressor, a separate blower, a separate compressor or a separate pump. 4. Arrangement (100) according to claim 1 or 2, characterized in that the conveying device (7) and the heating element (6) are formed as an integral component. 5. Arrangement (100) according to one of claims 1 to 4, characterized in that the heating element (6) is arranged downstream or upstream of the conveyor (7). 6. Arrangement (100) according to one of claims 1 to 5, characterized in that at least one first reducing agent injector (9) is provided for introducing a reducing agent into the gas channel arrangement (4), the channel (8) upstream of the reducing agent injector (9) opens into the gas channel arrangement (4). 7. Method for operating an internal combustion engine (1) with an exhaust gas aftertreatment system (2) and a preheating device (5), in particular designed according to one of the preceding claims, characterized in that a channel (at least one in at least one component (3)) 8) arranged heating element (6) of the preheating device (5) heated gas flow is conveyed using a conveying device (7) via a gas channel arrangement (4) through the exhaust gas aftertreatment system (2). 8. The method according to claim 7, characterized in that the gas flow in the course of the gas channel arrangement (4) after the internal combustion engine (1), ie on the exhaust gas side, from the preheating device (5), in particular from the heating element (6) of the preheating device (5) becomes. 9. The method according to claim 7 or 8, characterized in that the heated gas flow upstream or downstream of the component to be heated (3) of the exhaust gas aftertreatment system (2) from the channel (8) in the gas channel arrangement (2) is promoted. 10/13 PP31972AT AVL List GmbH 11/13 PP31972AT AVL List GmbH

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Classification of the subject of the application according to IPC: F01N 9/00 (2006.01); F01N 3/20 (2006.01) Classification of the application according to CPC: F01N9 / 00 (2018.08); F01N 3/2006 (2013.01); F01N 3/2093 (2013.01); F01N 2590/11 (2013.01); F01N 2240/12 (2013.01); F01N 2240/14 (2013.01); F01N 2240/16 (2013.01) Researched test substance (classification): F01N Consulted online database: EPODOC, WPI, TXTnn This search report was compiled on claims 1-9 filed on April 19, 2018. Category*· Title of the publication: Country code, publication number, document type (applicant), publication date, text or figure if necessary Regarding claim X A WO 9015955 Al (EMITEC EMISSIONSTECHNOLOGIE) December 27, 1990 (December 27, 1990) entire document WO 2015158948 Al (WÄRTSILÄ FINLAND OY) October 22, 2015 (October 22, 2015) entire document 1-9 1, 6 Date of completion of the research: 02/12/2019 Page 1 of 1 ^Examiner ( ⁱⁿ > ^: _{RnnTanFRr h H} RODLAUER Gerhard *) Categories of the listed documents: A Publication that defines the general state of the art. X Publication of special importance: the application P document that is of importance (categories X or Y), but after object cannot be published as new or published on the priority date of the registration solely due to this publication, inventive activity can be considered based. E Document of particular importance (Category X) from which Y Publication of importance: the subject of the application may not result in an "older right" (earlier filing date, however Novelty would be considered to be based on inventive step, if post-published protection is possible in Austria Make publication with one or more other publications), is associated with this category and this connection for & publication which is a member of the same patent family. is obvious to a specialist. 13/13