Internal combustion engine for a motor vehicle and motor vehicle

Abstract

This invention relates to an internal combustion engine (10) comprising: a combustion chamber (14), an intake system (12), an exhaust system (16), an exhaust gas treatment device (20) disposed within the exhaust system, an exhaust gas turbocharger (22), and a heating element (18) disposed upstream of the exhaust gas treatment device (20) within the exhaust system (16). The exhaust gas turbocharger has a compressor impeller as a first impeller (24) and a turbine impeller as a second impeller (26), and a motor, which can drive the engine to [operation name missing] during heating operation. With one impeller (24, 26) missing, air as a heating medium can be delivered into the exhaust system (16) by means of the at least one impeller (24, 26) during heating operation. The heating medium can be heated by means of the heating element (18). At least one pipe (28) is provided, which is fluidly connected to the exhaust system (16) at a first connection (30) arranged downstream of the exhaust gas treatment device (20) and at a second connection (32) arranged upstream of the heating element (18).

Description

TECHNICAL FIELD

[0001] The invention relates to an internal combustion engine for a motor vehicle according to the preamble of claim 1. The invention also relates to a motor vehicle. BACKGROUND

[0002] DE 10 2017 213 004 A1 discloses an internal combustion engine having an internal combustion engine, an air intake duct for supplying fresh air to the internal combustion engine, an exhaust system for discharging exhaust gases from the internal combustion engine and at least one exhaust gas treatment device integrated in the exhaust system. The internal combustion engine further comprises an electrically driven compressor integrated into the air intake duct or the exhaust system and a heating device for heating the gases flowing through it, which is arranged before the exhaust gas treatment device or integrated therein. The internal combustion engine has a control device which, when the temperature of one of the internal combustion engine components is below a specified limit value, operates the compressor simultaneously with the heating device as required when the internal combustion engine is not in operation.

[0003] Furthermore, DE 10 2018 129 955 A1 discloses a pre-warming method for an exhaust gas device for discharging and cleaning combustion exhaust gases of an internal combustion engine, in particular of a motor vehicle internal combustion engine, in which air is heated in the exhaust gas device by a heating element. A hot air flow is generated in the exhaust gas device with the heated air by means of a blower, wherein a first catalyst of the exhaust gas device is heated to a minimum operating temperature by the hot air flow. SUMMARY

[0004] It is therefore an object of the present invention to provide an internal combustion engine and a motor vehicle, with which the heating of the exhaust gas treatment device can be carried out very advantageously and very quickly.

[0005] According to the invention, this object is achieved by an internal combustion engine having the features of claim 1 and by a motor vehicle having the features of claim 10. Advantageous designs having suitable inventive refinements are specified in the dependent claims.

[0006] A first aspect of the application relates to an internal combustion engine for a motor vehicle, which can be driven by the internal combustion engine via a drive shaft of the internal combustion engine. The internal combustion engine has at least one combustion chamber and an intake system through which air can flow, wherein the combustion chamber can be supplied with air by means of the intake system. The internal combustion engine further comprises an exhaust system through which exhaust gas from the combustion chamber can flow, wherein an exhaust gas treatment device for treating the exhaust gas is provided in the exhaust system. Furthermore, at least one heating element for heating the gas flowing through the exhaust system is provided in the exhaust system upstream of the exhaust gas treatment device. The internal combustion engine comprises an electrically assisted exhaust-gas turbocharger having a compressor wheel as a first impeller which is arranged in the intake system for compressing the air flowing through the intake system. The electrically assisted exhaust-gas turbocharger further has a turbine wheel as a second impeller which is arranged in the exhaust system and can be driven by the exhaust gas, and an electric machine. At least one of the two impellers can be driven by means of the electric machine in a heating operation for heating the exhaust gas treatment device, whereby in the heating operation, in which no combustion process in the combustion chamber takes place and the drive shaft is at rest, air as a heating medium can be fed into the exhaust system by means of the at least one impeller. The heating medium can be heated by means of the heating element in the heating operation for heating the exhaust gas treatment device. The heating medium is thus, for example, the gas or a gas which can be heated or warmed up by means of the heating element.

[0007] According to the application, the internal combustion engine has at least one line element which is in fluid connection to the exhaust system at a first connection point arranged downstream of the exhaust gas treatment device and at a second connection point arranged upstream of the heating element. By means of the line element, at least a portion of the heating medium can be fed back from the first connection point to the second connection point and into the exhaust system at the second connection point.

[0008] The motor vehicle is preferably designed as a car, in particular as a passenger car. The internal combustion engine can be designed as a piston engine and has an engine block which comprises the combustion chamber. By means of the intake system, fluid, generally air, flows into the combustion chamber. In the ignition operation, a combustion process takes place in the combustion chamber. A fuel-air mixture is combusted in each combustion process, whereby the exhaust gas of the internal combustion engine is produced.

[0009] In an exhaust system, which can also be referred to as exhaust gas system, an exhaust gas treatment device is arranged for treating exhaust gas. In other words, the exhaust gas treatment device serves for purifying exhaust gas by means of, inter alia, at least one catalytic converter and / or at least one filter, for example a particulate filter. By means of the catalytic converter, harmful substances present in the exhaust gas, such as, for example, carbon monoxide, nitrogen monoxide, nitrogen dioxide or unburned hydrocarbons, are converted into harmless substances by means of at least one chemical reaction. The catalytic converter refers, inter alia, to a component which, inter alia, reduces the activation energy of a chemical reaction, as a result of which the chemical reaction takes place at a very rapid reaction speed. The activation energy is, inter alia, the energy required for the chemical reaction to start. The reaction speed is, inter alia, the speed at which the chemical reaction takes place. The component which is referred to as a filter, inter alia, retains solids from a gas or liquid flow. As a result, solid substances or harmful substances, which can be referred to as particulates or soot, inter alia, are filtered out of the exhaust gas.

[0010] In order to achieve a very good exhaust gas cleaning of the internal combustion engine, it is advantageous if the exhaust gas treatment device, in particular the catalytic converter, has a minimum temperature, which can be referred to as conversion temperature or light-off temperature or start-up temperature, inter alia. For this purpose, heating of the exhaust gas treatment device is required, inter alia, at a cold start. The cold start refers, inter alia, to the internal combustion engine being put into operation, started, brought into operation or activated, at which time the temperature of the internal combustion engine corresponds approximately to the ambient temperature. At the start of the internal combustion engine, the internal combustion engine is brought from a state in which no combustion process takes place in the combustion chamber and the drive shaft is at a standstill, which is also referred to as engine stop, into an activated state, which is referred to as ignition operation, inter alia. After the cold start, the exhaust gas treatment device is heated by means of the exhaust gas. In particular in vehicles having a combination of an internal combustion engine and electrically powered travel, the heating or tempering of the exhaust system by means of the exhaust gas is very difficult, since the exhaust gas mass flow can be small or non-existent in many operating states. The electrically powered travel of a motor vehicle is referred to as electric travel, in which the motor vehicle is driven at least partially by an electric machine.

[0011] A heating element arranged in the exhaust system upstream of the exhaust gas treatment device can, inter alia, accelerate the heating of the exhaust gas treatment device, in particular after a cold start. The heating element is designed in such a way that it heats a gas, for example exhaust gas, which flows through or around the heating element. The gas is exhaust gas in the normal operation of the internal combustion engine and / or at a cold start, and is air in a heating operation of the internal combustion engine which differs from the normal operation, which is heated by means of the heating element and used as a heating medium for the heating or warming of the exhaust gas treatment device.

[0012] In order to achieve a very advantageous and rapid heating of the exhaust-gas treatment device, a line piece according to the application is provided. In the heating operation, the heating medium can be fed to the heating piece from the intake system, for example, by means of an electric, electrically assisted or electrically assistable exhaust-gas turbocharger, and / or the heating medium can be fed in the exhaust system and at the same time, in particular, via the line piece, be circulated. In this case, at least one of the two impellers is driven by means of an electric motor with electrical energy, which can be taken, in particular, from a power supply device, which is referred to as on-board power supply. By means of the line piece, at least a part of the heating medium, which is heated by the heating piece, can be recirculated after flowing through the exhaust-gas treatment device back to the heating piece and the exhaust-gas treatment device, whereby a recirculation circuit occurs. In this way, not only the exhaust-gas treatment device is heated, but also other components of the exhaust system. Thereby, there is a small temperature gradient between the exhaust-gas treatment device and the exhaust-system components around it, whereby little heat is emitted from the exhaust-gas treatment device to the surrounding exhaust-system components. In other words, the heat loss of the exhaust-gas treatment device is low. Thereby, the heating and the thermal insulation of the exhaust-gas treatment device can be arranged very efficiently. Furthermore, the heating medium can be brought to a very high temperature very quickly, whereby the exhaust-gas treatment device can be efficiently effectively heated. The recirculation circuit can be operated, in particular, when the engine is stopped. The feeding of the heating medium in the recirculation circuit can be carried out, in particular, by means of or at least with the aid of the electrically driven at least one impeller, in particular, by means of the second impeller. In other words, the recirculation circuit can be maintained by means of the electrically driven at least one impeller. Thereby, a tempering of the exhaust-gas treatment device can be achieved, in particular, when the engine is stopped. Thereby, little harmful substances are emitted from the internal combustion engine, in particular, after a cold start.

[0013] In one embodiment of the application, a valve piece is provided in the line piece, by means of which the quantity of heating medium flowing through the line piece can be adjusted. For this purpose, the valve piece can be connected to a regulating device, which is indicated, for example, by a control device or is referred to as control device. The line piece can be closed only partially or completely by means of the valve piece.

[0014] In another design of the application, the internal combustion engine has an exhaust gas recirculation line which fluidically communicates to the exhaust system at a tapping point arranged downstream of the turbine wheel, in particular downstream of the exhaust gas treatment device. In addition, the exhaust gas recirculation line fluidically communicates to the intake system at a tapping point. The tapping point can be arranged upstream or downstream of the compressor wheel within the intake system. By means of the exhaust gas recirculation line, at least a portion of the exhaust gas can be tapped off from the exhaust system at the tapping point and fed into the exhaust gas recirculation line. The exhaust gas fed into the exhaust gas recirculation line can flow through the exhaust gas recirculation line and be guided by means of the exhaust gas recirculation line to the tapping point and fed into the intake system at the tapping point, which can be referred to as low-pressure exhaust gas recirculation, in particular. Thereby, the exhaust gas can be guided into the combustion chamber. The portion of the exhaust gas already present in the combustion chamber before the start of the combustion process can be kept free of harmful substances generated during the combustion process. Here, it can be one or both of nitrogen monoxide and nitrogen dioxide, both of which are referred to as nitrogen oxides, in particular. In a heating operation, for example, at least a portion of the heating medium can be guided from the tapping point to the tapping point and fed into the intake system at the tapping point.

[0015] In another embodiment, an exhaust gas recirculation valve is provided in the exhaust gas recirculation line, by means of which the amount of exhaust gas and / or the amount of heating medium flowing through the exhaust gas recirculation line can be adjusted. To this end, the exhaust gas recirculation valve can be connected to a regulating device and controllable and thereby operable by the regulating device. The exhaust gas recirculation line can be closed, for example, by means of the exhaust gas recirculation valve only partially or completely.

[0016] A further embodiment is characterized in that the internal combustion engine has a recirculation line which fluidically communicates to the exhaust system at a third connection point arranged upstream of the turbine wheel and to the intake system at a fourth connection point. The fourth connection point can preferably be arranged downstream of the compressor wheel. By means of the recirculation line, for example, at least a portion of the exhaust gas flowing through the exhaust system can be tapped off from the exhaust system and fed into the recirculation line. The exhaust gas fed into the recirculation line can flow through the recirculation line in a first flow direction and thereby be guided by means of the recirculation line from the third connection point to the fourth connection point and fed into the intake system at the fourth connection point, which can be referred to as high-pressure exhaust gas recirculation, in particular. In a heating operation, at least a portion of the heating medium or the entire heating medium can be tapped off from the intake system at the fourth connection point and fed into the recirculation line. The exhaust gas fed into the recirculation line can flow through the recirculation line in a second flow direction opposite the first flow direction and be guided by means of the recirculation line from the fourth connection point to the third connection point. Here, the heating medium is guided from the intake system into the exhaust system bypassing the combustion chamber or all combustion chambers of the internal combustion engine and to the heating element, whereby the heating medium and, in turn, the exhaust gas treatment device can be heated very effectively.

[0017] In another embodiment of the application, a return flow valve is provided in the return flow line, by means of which the amount of exhaust gas and / or the amount of heating medium flowing through the return flow line can be adjusted. To this end, the return flow valve can be connected to the regulating device and can be actuated by the regulating device. The return flow line is, for example, only partially or completely closable by means of the return flow valve.

[0018] It has finally proven to be particularly advantageous if the heating element has at least one electric heating element and / or at least one burner and / or at least one electric catalyst. An electric heating element is understood to mean, in particular, a heating element which converts electrical current into heat. A burner is understood to mean, in particular, a heating element in which at least one fuel, in particular in liquid or gaseous form, is combusted with the formation of a flame or without a flame and thus in a catalytic manner, in particular releases heat or emits heat. An electric catalyst is understood to mean, in particular, a catalyst which is heated or can be heated by means of an electric heating element, wherein the electric heating element is, for example, fixed on the catalyst housing and / or can be connected to the catalytic structure or catalytically acting structure of the catalyst.

[0019] A second aspect of the application relates to a motor vehicle having an internal combustion engine according to the first aspect of the application. The advantages and advantageous designs of the first aspect of the application are to be regarded as advantages and advantageous designs of the second aspect of the application and vice versa. The motor vehicle according to the application is preferably designed as a car, in particular as a passenger car or a truck or a bus or a motorcycle.

[0020] Further advantages, features and details of the application result from the following description of preferred embodiments and in conjunction with the drawings. The features mentioned in the description and the features shown in the drawings alone or in any combination are not to be regarded as essential to the application, but rather merely as advantageous designs. The features mentioned in the description and the features shown in the drawings alone or in any combination are not to be regarded as essential to the application, but rather merely as advantageous designs. BRIEF DESCRIPTION OF DRAWINGS

[0021] The drawing shows a schematic view of an internal combustion engine according to the application in a single drawing. DETAILED DESCRIPTION

[0022] The single drawing shows schematically an internal combustion engine 10 for a motor vehicle, in particular for a car, preferably designed as a passenger car. Here, the motor vehicle can be driven by means of the internal combustion engine 10. The internal combustion engine 10 has an intake system 12, at least one cylinder and an exhaust system 16. The cylinder partially delimits a combustion chamber 14. The internal combustion engine 10 has a piston which is translatory movably accommodated in the cylinder. The piston partially delimits the combustion chamber 14. In the embodiment as shown, it is a four-cylinder engine comprising exactly four combustion chambers 14.

[0023] The intake system can be flowed through by a fluid in the form of air, which is guided into the combustion chamber 14 by means of the intake system. In the combustion chamber 14, a combustion process takes place during the ignition operation of the internal combustion engine 10, thereby causing exhaust gases of the internal combustion engine 10. The exhaust gases can flow through an exhaust system 12, which is referred to as exhaust gas device, and exit the combustion chamber 14 via the exhaust system 12. At least one heating element 18 and an exhaust gas treatment device 20 are arranged in the exhaust system 16, wherein the heating element 18 is arranged upstream of the exhaust gas treatment device 20. The exhaust gas treatment device 20 comprises at least one exhaust gas purification component. The exhaust gas purification component can be designed, for example, as an oxidation catalyst, in particular a diesel oxidation catalyst (DOC), a NO x storage catalyst (NSK), a SCR catalyst (selective catalytic reduction catalyst), a diesel particulate filter (DPF) or a diesel particulate filter with SCR catalyst (SDPF).

[0024] The oxidation catalyst refers in particular to a catalyst which removes carbon monoxide and unburnt hydrocarbons from the exhaust gases by means of oxidation with surplus oxygen. The surplus oxygen refers in particular to oxygen molecules which did not take part in the chemical reactions during the combustion process and are therefore available as oxygen for other chemical reactions. The NO x The storage catalyst (NSK) refers in particular to a catalyst which has a storage portion in which nitrogen oxides are chemically bound and thus removed from the exhaust gases. The nitrogen oxides can then be released again from the storage portion in an internal combustion engine operating state in which the exhaust gases are oxygen-poor and reduced with a reducing component, such as unburnt hydrocarbons or carbon monoxide. The SCR catalyst refers in particular to a catalyst in which nitrogen oxides are reacted with urea from an input urea solution in a redox reaction to form nitrogen and water. The diesel particulate filter (DPF) refers in particular to a filter which removes the particles also referred to as soot or dust from the exhaust gases.

[0025] The internal combustion engine 10 also has an electric, electrically assisted or electrically assistable exhaust-gas turbocharger 22, which comprises a compressor wheel as a first wheel 24, which is arranged in the intake system 12, a turbine wheel as a second wheel 26, which is arranged in the exhaust system 16, and a shaft. The first wheel 24 and the second wheel 26 are arranged on the shaft and are rotationally coupled to the shaft. The first wheel 24, the second wheel 26 and the shaft are, for example, components which are constructed separately from one another, which are connected to one another in such a way that relative movements between these components and movements relative to one another in the axial and radial direction of the shaft are inhibited or avoided. The first wheel 24 is used, for example, to compress air which can be supplied to the combustion chamber 14 via the intake system 12. By means of the second wheel 26, exhaust gas which flows from the combustion chamber 14 into the exhaust system 16 is expanded, as a result of which the second wheel 26 is driven by the exhaust gas. Furthermore, the internal combustion engine 10 has an electric machine, by means of which the exhaust-gas turbocharger 22 can be driven using electrical energy. The electric machine can be designed in such a way that it drives the shaft of the exhaust-gas turbocharger 22, as a result of which the first wheel 24 and the second wheel 26 are driven by means of the shaft. Alternatively, the electric machine can be designed in such a way that the first wheel 24 and / or the second wheel 26 can be driven directly by the electric machine. This means that the shaft is not driven directly by the electric machine. The internal combustion engine 10 also has a driven shaft, which is designed, for example, as a crankshaft, by means of which the internal combustion engine can provide a torque for driving a motor vehicle, in particular in a firing operation of the internal combustion engine 10. In a heating operation of the internal combustion engine 10, air is conveyed as a heating medium into the exhaust system 16 by means of the electrically assisted exhaust-gas turbocharger 22, in that at least one of the two wheels 24, 26 is driven electrically by means of the electric machine. During the heating operation, no combustion process takes place in the combustion chamber or all combustion chambers 14 of the internal combustion engine, and the driven shaft is at rest during the heating operation. Furthermore, in the heating operation, the heating medium is heated by means of the heating element 18, so that the exhaust-gas treatment device 20 is heated or warmed up in the heating operation by means of the heated heating medium.

[0026] In order to be able to heat the exhaust-gas treatment device 20 particularly advantageously and very quickly at present, the internal combustion engine 10 has at least one line piece 28, which is in fluid connection to the exhaust system 16 at a first connection point 30 arranged downstream of the exhaust-gas treatment device 20 and at a second connection point 32 arranged upstream of the heating piece 18, in particular upstream of the turbine wheel 26. By means of the line piece 28, at least a portion of the heating medium flowing through the exhaust system 16 can be tapped off from the exhaust system 16 at the first connection point 30 and can flow back from the first connection point 30 to the second connection point 32 and can be fed into the exhaust system 16 at the second connection point 32. Thereby, a flow back of the heating medium can be achieved, since the heating medium is tapped off from the first connection point 30 by means of the line piece 28 to the second connection point 32 arranged upstream in comparison and is fed into the exhaust system 16. The flow back of the heating medium forms a first recirculation circuit, in which or by means of which the heating medium can be circulated between the connection points 30, 32. The first recirculation circuit can be operated by means of the electric exhaust-gas turbocharger 22, in particular in a state which is referred to as engine stop. Thereby, the exhaust-gas treatment device 20 can be heated in advance and thus advantageously temperature-adjusted at engine stop. Thus, the internal combustion engine 10 has a low emission of harmful substances. Engine stop means that no combustion process is taking place in the internal combustion engine 10 and the drive shaft is at rest.

[0027] A valve piece 34 is arranged in the line piece 28, by means of which the quantity of heating medium flowing through the line piece 28 can be adjusted. To this end, the valve piece 28 can be connected to an adjusting device, for example in the form of a control device.

[0028] By means of an exhaust-gas valve piece 35, for example designed as an exhaust-gas flap, arranged in the exhaust system 16 downstream of the first connection point 30, the exhaust-gas mass flow leaving the internal combustion engine 10 and / or the heating medium mass flow is reduced or prevented or intercepted. In order to achieve a specified mass flow, the exhaust-gas valve piece 35 can be connected to an adjusting device, for example a control device, and can be actuated and thereby operated, in particular controlled or adjusted. By means of at least partial closure of the exhaust system 16 by means of the exhaust-gas valve piece 35, a very large quantity of heating medium can be caused to flow through the recirculation circuit, i.e. to circulate through or along the recirculation circuit. This recirculation circuit comprises the line piece 28, so that the heating medium flowing through the recirculation circuit flows through the line piece 28 and thus circulates through the line piece 28. By means of the circulation or recirculation, the exhaust-gas treatment device 20 can be heated very quickly and effectively.

[0029] The internal combustion engine 10 has an exhaust gas recirculation line 36. The exhaust gas recirculation line 36 is fluidly connected to the exhaust system 16 at a branch section 38 located downstream of the exhaust gas treatment device 20. Additionally, the exhaust gas recirculation line 36 is fluidly connected to the intake system 12 at an inlet section 40. By means of the exhaust gas recirculation line 36, at least a portion of the exhaust gas flowing through the exhaust system 16 can be guided from the branch section 38 to the inlet section 40 and then fed into the intake system 12, especially during ignition operation. The inlet section is located downstream of the first impeller 24 within the intake system, but may also be located upstream of the first impeller 24, which is not shown in the figures. During heating operation, at least a portion of the heating medium can be guided from the branch section 38 to the inlet section 40 and then fed into the intake system 12. Therefore, during heating operation, a second recirculation loop for the heating medium can be formed through the exhaust gas recirculation line 36. The heating medium is supplied via an electrically operated first impeller 24 and / or an electrically operated second impeller 26 of the exhaust gas turbocharger 22. The second recirculation loop can operate independently of or in conjunction with the first recirculation loop. An exhaust gas recirculation valve 42 is provided in the exhaust gas recirculation line 36, thereby regulating the amount of exhaust gas and / or heating medium flowing through the exhaust gas recirculation line 36. For this purpose, the exhaust gas recirculation valve 42 can be connected to a regulating device, for example, in the form of a control device.

[0030] The internal combustion engine 10 has a return line 44, which is fluidly connected to the exhaust system at a third connection 46 located upstream of the second impeller 26 and fluidly connected to the intake system 12 at a fourth connection 48. The fourth connection 48 is preferably located downstream of the first impeller 24. Through the return line 44, at least a portion of the exhaust gas can be guided from the third connection 46 to the fourth connection 48 in a first flow direction and can be fed into the intake system 12 from the fourth connection 48. During heating operation, the heating medium can be guided from the fourth connection 48 to the third connection 46 in a second flow direction opposite to the first flow direction and can be fed into the exhaust system 16 from the third connection 46. Here, the heating medium is delivered from the intake system to the heating element 18, at least by means of the electrically operated first impeller 24, bypassing the combustion chamber 14. A return valve 50 is provided in the return line 44, thereby allowing adjustment of the amount of exhaust gas or heating medium flowing through the return line 44. For this purpose, the return valve 50 can be connected to a regulating device, for example, in the form of a control device.

[0031] The heating element 18 may have an electric heating element and / or a burner and / or an electric catalytic converter.

[0032] List of reference numerals in the attached diagram:

[0033] 10 Internal Combustion Engine

[0034] 12. Intake System

[0035] 14 Combustion Chamber

[0036] 16. Exhaust System

[0037] 18 Heating element

[0038] 20 Waste Gas Treatment Device

[0039] 22 Exhaust Gas Turbocharger

[0040] 24 Compressor impeller

[0041] 26 Turbine impeller

[0042] 28 Piping fittings

[0043] 30 First connecting part

[0044] 32 Second connection part

[0045] 34 Valves

[0046] 35 Exhaust gas valve components

[0047] 36. Exhaust gas return pipeline

[0048] 38. Discharge site

[0049] 40. Access point

[0050] 42 Exhaust gas recirculation valve

[0051] 44 Return Piping

[0052] 46 Third connection part

[0053] 48 Fourth connection part

[0054] 50 reflux valve

Claims

1. An internal combustion engine (10) for a motor vehicle, comprising: - A driven shaft that can drive a motor vehicle via an internal combustion engine (10); - An intake system (12) through which air flows into at least one combustion chamber (14) of the internal combustion engine (10); - An exhaust system (16) through which exhaust gas from the combustion chamber (14) passes; - An exhaust gas treatment device (20) installed in the exhaust system for treating exhaust gases; - At least one heating element (18) for heating the gas flowing through the exhaust system (16) and disposed upstream of the exhaust gas treatment device (20); - An electrically assisted exhaust gas turbocharger (22) having a compressor impeller as a first impeller (24), a turbine impeller as a second impeller (26), and a motor. The compressor impeller is located in the intake system (12) and is used to compress the air flowing through the intake system (12). The turbine impeller is located in the exhaust system (16) and can be driven by exhaust gas. The motor can drive at least one of the impellers (24, 26) during heating operation for heating the exhaust gas treatment device (20). Therefore, during heating operation where combustion does not occur in the combustion chamber (14) and the driven shaft is stationary, air can be delivered to the exhaust system (16) as a heating medium by means of at least one impeller (24, 26). This heating medium can be heated by means of a heating element (18) during heating operation for heating the exhaust gas treatment device (20). Its features are, At least one pipe component (28) is provided, which is fluidly connected to the exhaust system (16) at a first connection (30) downstream of the exhaust gas treatment device (20) and at a second connection (32) upstream of the heating element (18), so that at least a portion of the heating medium can be returned from the first connection (30) to the second connection (32) and can be sent into the exhaust system (16) at the second connection (32).

2. The internal combustion engine (10) according to claim 1, characterized in that, A valve (34) is provided inside the pipe fitting (28), by means of which the amount of heating medium that can flow through the pipe fitting (28) can be adjusted.

3. The internal combustion engine (10) according to claim 1 or 2, characterized in that, An exhaust gas return line (36) is provided, which is fluidly connected to the exhaust system (16) at a branch section (38) located downstream of the turbine impeller (26) and fluidly connected to the intake system (12) at an inlet section (40). Thus, at least a portion of the exhaust gas and / or at least a portion of the heating medium during heating operation can be guided from the branch section (38) to the inlet section (40) and sent into the intake system (12) at the inlet section (40).

4. The internal combustion engine (10) according to claim 1 or 2, characterized in that, An exhaust gas return line (36) is provided, which is fluidly connected to the exhaust system (16) at a branch section (38) located downstream of the exhaust gas treatment device (20) and fluidly connected to the intake system (12) at an inlet section (40). Therefore, at least a portion of the exhaust gas and / or at least a portion of the heating medium during heating operation can be guided from the branch section (38) to the inlet section (40) and sent into the intake system (12) at the inlet section (40).

5. The internal combustion engine according to claim 3, characterized in that, The inlet (40) is located upstream or downstream of the compressor impeller (24).

6. The internal combustion engine (10) according to claim 3, characterized in that, An exhaust gas return valve (42) is provided in the exhaust gas return pipe (36), by means of which the amount of exhaust gas and / or heating medium flowing through the exhaust gas return pipe (36) can be adjusted.

7. The internal combustion engine (10) according to claim 1 or 2, characterized in that, A return pipe (44) is provided, which is fluidly connected to the exhaust system (16) at a third connection (46) located upstream of the turbine impeller (26) and fluidly connected to the intake system (12) at a fourth connection (48). Therefore, at least a portion of the exhaust gas can be guided from the third connection (46) to the fourth connection (48) and can be sent to the intake system (12) at the fourth connection (48), and / or during heating operation, at least a portion of the heating medium can be guided from the fourth connection (48) to the third connection (46) and can be sent to the exhaust system (16) at the third connection (46).

8. The internal combustion engine (10) according to claim 7, characterized in that, The fourth connection part (48) is located downstream of the compressor impeller (22).

9. The internal combustion engine (10) according to claim 7, characterized in that, A return valve (50) is provided in the return pipe (46), by means of which the amount of exhaust gas and / or heating medium flowing through the return pipe (44) can be adjusted.

10. The internal combustion engine (10) according to claim 1 or 2, characterized in that, The heating element (18) has at least one heating element and / or burner.

11. A motor vehicle having an internal combustion engine (10) according to any one of claims 1 to 10.

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