DE102019122315A1 - Method for monitoring an electrically heatable catalytic converter - Google Patents

Abstract

The invention relates to a method for monitoring an electrically heatable catalytic converter (28) in an exhaust system (20) of an internal combustion engine (10). A temperature sensor (40) with which a temperature in the exhaust system (20) can be measured is arranged in the exhaust system (20) upstream of the electrically heatable catalytic converter (28). The method comprises the following steps: - electrical heating of the electrically heatable catalytic converter (28), the temperature sensor (40) being heated by the thermal radiation of the electrically heatable catalytic converter (28), wherein electrically heatable catalyst (28) is determined in the exhaust system (20). The invention also relates to an exhaust system (20) in which an electrically heatable catalyst (28) and a temperature sensor (40) arranged upstream of the electrically heatable catalyst (28) are provided are, as well as with a control unit (50) for performing such a method.

Description

The invention relates to a method for monitoring an electrically heatable catalytic converter in an exhaust system of an internal combustion engine and an exhaust system with an electrically heatable catalytic converter according to the preamble of the independent claims.

The continuous tightening of exhaust gas legislation places high demands on vehicle manufacturers, which are met by appropriate measures to reduce engine raw emissions and by appropriate exhaust gas aftertreatment. In order to be able to effectively implement the raw emissions that cannot be completely avoided after the engine, catalytic converters coated with precious metal are installed in the exhaust system of the internal combustion engine. So that these catalytic converters can convert the pollutants, a minimum temperature level of the exhaust gas and the catalytic converter is necessary. In order to bring the catalytic converter up to operating temperature as quickly as possible after a cold start of the internal combustion engine, engine heating measures such as adjusting the ignition angle or fuel injection in the "retarded" direction or under-stoichiometric operation of the internal combustion engine with simultaneous introduction of secondary air are used. In order to bring even more thermal energy into the exhaust system in a targeted manner, it is possible to heat the catalytic converter electrically or to install a switchable exhaust gas burner on the exhaust system to feed hot exhaust gas into the exhaust system and to heat the exhaust gas aftertreatment components in the exhaust system independently of the combustion engine. This means that emissions can already be significantly reduced in the heating phase of the catalytic converter.

In diesel engines, late post-injection and / or a shift in the center of combustion in the "late" direction are known to increase the exhaust gas temperature, with the thermal efficiency of the internal combustion engine decreasing and more energy being introduced into the exhaust system. At the same time, by shifting the main injection in the "late" direction, the raw emissions of nitrogen oxides can be reduced.

A disadvantage of the solutions known from the prior art, however, is that heating measures within the engine only become effective after the internal combustion engine has been started. In addition, these internal engine heating measures can lead to fuel entering the engine oil, which increases wear or the oil change intervals have to be shortened.

Furthermore, external heating means in the exhaust system, such as an exhaust gas burner or an electrical heating element, are known from the prior art. The exhaust gas aftertreatment components can be heated essentially independently of the exhaust gas flow of the internal combustion engine by external heating means and thus reach their operating temperature more quickly, whereby the tailpipe emissions can be reduced in particular in a cold start phase of the internal combustion engine.

The DE 10 2016 122 304 A1 discloses a method for heating an electrically heatable catalytic converter in an exhaust duct of a motor vehicle with an internal combustion engine. In order to heat up the catalytic converter before the internal combustion engine is started, it is provided that the catalytic converter is electrically heated before the internal combustion engine is started and enables efficient exhaust gas aftertreatment as soon as the engine is started. After an electrical preheating phase after starting the engine, the catalyst is further heated by a combined electrical and chemical heating through the exothermic conversion of unburned fuel components on a catalytically active surface of the electrically heatable catalyst.

From the DE 10 2017 113 320 A1 a method and a system for unevenly heating an electrically heatable catalyst in the exhaust system of an internal combustion engine are known. The method includes providing a catalyst made up of a plurality of electrically conductive subsections and at least one catalyst heating element capable of heating at least one of the various electrically conductive subsections of the catalyst to form at least one predetermined non-uniform heating pattern. A heater controller is provided to control operation of the at least one heating element of the catalytic converter. When the internal combustion engine is in a cold start condition, the heating control module causes at least one of the catalyst heating elements to heat at least one of the electrically conductive sections of the catalyst to obtain a first predetermined non-uniform heating pattern.

The invention is based on the object of enabling the function of the electrical heating element to be monitored as simply and inexpensively as possible in an electrically heatable catalytic converter.

• - elektrisches Beheizen des elektrisch beheizbaren Katalysators, wobei
• - der Temperatursensor durch die Wärmestrahlung des elektrisch beheizbaren Katalysators aufgeheizt wird, wobei
• - die vom Temperatursensor gemessene Temperatur um den Kühleffekt durch den Abgasmassenstrom korrigiert wird, wobei
• - durch die Aufheizung des Temperatursensors ein Wärmeeintrag des elektrisch beheizbaren Katalysators in die Abgasanlage ermittelt wird.

According to the invention, this object is achieved by a method for monitoring an electrically heatable catalytic converter in an exhaust system of an internal combustion engine. The electrically heated one is upstream in the exhaust system Catalyst arranged a temperature sensor with which a temperature in the exhaust system can be measured. The process consists of the following steps:

• - electrical heating of the electrically heatable catalyst, wherein
• - The temperature sensor is heated by the thermal radiation of the electrically heatable catalyst, wherein
• - The temperature measured by the temperature sensor is corrected for the cooling effect caused by the exhaust gas mass flow, wherein
• - By heating the temperature sensor, a heat input from the electrically heatable catalytic converter into the exhaust system is determined.

A method according to the invention makes it possible to monitor the electrical heating output of an electrically heatable catalytic converter. The sensors already present in the exhaust system can be used so that the method can be implemented simply and inexpensively. No additional space is required for additional sensors in the exhaust system. Furthermore, an on-board diagnosis of the electrically heatable catalytic converter can be carried out so that a failure can be detected which would directly lead to an increase in the tailpipe emissions.

The features listed in the dependent claims allow advantageous improvements and further developments of the method specified in the independent claim for monitoring an electrically heatable catalytic converter.

In a preferred embodiment of the invention, it is provided that the determined heating of the temperature sensor is compared with the heating to be expected at a defined heating power at a given exhaust gas mass flow, and the functionality of the electrically heatable catalytic converter is monitored on the basis of this comparison. The general rule here is that the greater the exhaust gas mass flow, the smaller the expected heating. This enables a quantitative analysis of the heating power introduced. It can thus be recognized in good time when the heating output of the electrically heatable catalytic converter is decreasing. A threshold value can be defined, from which an exchange of the electrical heating element of the electrically heatable catalytic converter is necessary.

In a preferred embodiment of the invention it is provided that the determined gradient of the heating of the temperature sensor is compared with a gradient to be expected with a defined heating power at a given exhaust gas mass flow, and the functionality of the electrically heatable catalytic converter is monitored on the basis of this comparison. This results in a dependency on the exhaust gas mass flow of the internal combustion engine, which generally applies that the greater the exhaust gas mass flow, the lower the gradient to be expected for the heating. As a result, a quantitative analysis of the heating power introduced can be estimated immediately after the start of the heating phase. It can thus be recognized in good time when the heating output of the electrically heatable catalytic converter is decreasing.

It is particularly preferred if the defined heating output is the maximum electrical heating output of the electrically heatable catalytic converter. Since the heat flow radiated by a body increases exponentially with temperature, a greater heating output of the electrically heatable catalytic converter leads to a significant increase in heat radiation. In order to determine the temperature increase at the temperature sensor as a result of the thermal radiation, the highest possible, in particular the maximum heating power of the electrically heatable catalytic converter, is therefore useful for monitoring the functionality.

In a further preferred embodiment of the invention it is provided that the electrically heatable catalyst is electrically heated for at least 15 seconds, preferably for at least 30 seconds, particularly preferably for at least 45 seconds, the temperature change of the temperature sensor being determined on the heat input. To heat the electrically heated catalytic converter or a catalytic converter immediately downstream of the electrically heated catalytic converter to its light-off temperature, it makes sense to electrically heat the electrically heated catalytic converter for at least 45 seconds in order to ensure sufficient energy input into the exhaust system. To analyze the functionality, it is also helpful to electrically heat the electrically heatable catalytic converter for at least 20 seconds in order to ensure that the electrically heatable catalytic converter is heated to its maximum possible temperature and to ensure a correspondingly high level of thermal radiation.

According to the invention, an exhaust system for an internal combustion engine with at least one combustion chamber is proposed, the internal combustion engine being connectable with its outlet to the exhaust system. In this case, at least one catalytic converter is arranged in the exhaust system and an electrically heatable catalytic converter is arranged upstream of the catalytic converter. A temperature sensor is arranged downstream of the outlet of the internal combustion engine and upstream of the electrically heatable catalytic converter. The temperature sensor and the electrical Heatable catalytic converters are connected to a control device which is set up to carry out a method according to the invention when a machine-readable program code is executed by the control device. A temperature sensor downstream of the catalytic converter would only allow a greatly delayed determination of a temperature rise in the exhaust system, since the catalytic converter initially absorbs heat in order to warm itself up. Furthermore, the exothermic, catalytic reactions on the catalytic converter also lead to an increase in temperature, so that the amount of heat introduced by the electrically heatable catalytic converter would be difficult and time-delayed to determine. By arranging the temperature sensor upstream of the electrically heatable catalytic converter, the convective component of the heat transfer is eliminated, but an increase in the sensor temperature due to the thermal radiation can be measured directly.

With such an exhaust system, monitoring of an electrically heatable catalytic converter in the exhaust system can take place in a comparatively simple and inexpensive manner. It can be recognized when the electrically heatable catalytic converter has a malfunction, in particular an insufficient heating output, and there is a risk that the malfunction will result in insufficient conversion of the pollutants in the exhaust gas of the internal combustion engine.

In a preferred embodiment of the exhaust system it is provided that the electrically heatable catalytic converter comprises an electrical heating element, in particular an electrical heating disk. An electrical heating element, which is connected upstream of a catalytic converter, can convectively ensure rapid heating of the catalytic converter by means of the exhaust gas flow. The heating element radiates heat, which leads to the temperature sensor being heated upstream of the electrically heatable catalytic converter.

According to a preferred embodiment of the exhaust system, it is provided that the catalytic converter is designed as an oxidation catalytic converter or as a NOx storage catalytic converter. Since electrically heatable catalytic converters are often used in exhaust systems of diesel engines, the use of such an electrically heatable catalytic converter as the first catalytic converter in the direction of flow of an exhaust gas of the internal combustion engine makes sense.

Alternatively, it is advantageously provided that the catalytic converter is designed as a three-way catalytic converter or as a four-way catalytic converter. In gasoline engines, the arrangement of an electrically heatable catalytic converter as the first catalytic converter directly upstream of a catalytic converter close to the engine, in particular a three-way catalytic converter or four-way catalytic converter, is helpful in reducing cold start emissions. In this context, a close-coupled catalytic converter is to be understood as a catalytic converter whose inlet-side end face is arranged with an exhaust gas run length of less than 80 cm, preferably less than 50 cm, from an outlet of the internal combustion engine.

In a further advantageous embodiment of the exhaust system it is provided that the catalytic converter is designed as an SCR catalytic converter or as a particle filter with a catalytically active coating, in particular with a coating for the selective, catalytic reduction of nitrogen oxides (SCR coating). In diesel engines in particular, it can be helpful to arrange an electrically heatable catalytic converter directly upstream of an SCR catalytic converter or a particle filter with an SCR coating in order to heat the SCR catalytic converter or the particle filter to a temperature necessary for selective catalytic reduction. In order to be able to monitor such an electrically heatable catalyst, the proposed method is also suitable.

In a preferred embodiment of the invention it is provided that the temperature sensor is arranged a maximum of 5 cm, preferably a maximum of 3 cm, upstream of the electrically heatable catalytic converter. Since the thermal radiation decreases sharply with distance, it is expedient to arrange the temperature sensor as close as possible to the electrically heatable catalytic converter in order to be able to measure heating by the thermal radiation. The distance from a central axis of the temperature sensor to an inlet-side end face of the electrically heatable catalytic converter is measured. A maximum distance of 5 cm ensures that strong heating of the electrically heatable catalytic converter leads to a functionally reliable and reproducible measurable temperature increase at the temperature sensor.

In an advantageous embodiment of the exhaust system it is provided that a turbine of an exhaust gas turbocharger is arranged in the exhaust system, the temperature sensor being arranged downstream of the turbine and upstream of the electrically heatable catalytic converter. In order to determine a measurable effect for the heating of the temperature sensor by the thermal radiation of the electrically heatable catalytic converter, the temperature sensor should be exposed to an exhaust gas that is as homogeneous as possible. The turbine ensures that the exhaust gas flow is mixed so that hot zones of the exhaust gas flow are mixed with comparatively cold zones and the temperature sensor is flowed against by a thermally essentially homogeneous exhaust gas.

The various embodiments of the invention mentioned in this application can be advantageously combined with one another, unless stated otherwise in the individual case.

• 1 ein erstes Ausführungsbeispiel für einen Verbrennungsmotor mit einer Abgasanlage zur Durchführung eines erfindungsgemäßen Verfahrens zur Überwachung eines elektrisch beheizbaren Katalysators;
• 2 ein weiteres Ausführungsbeispiel für einen Verbrennungsmotor mit einer Abgasanlage zur Durchführung eines erfindungsgemäßen Verfahrens zur Überwachung eines elektrisch beheizbaren Katalysators; und
• 3 einen Temperaturverlauf an einem Temperatursensor in der Abgasanlage bei der Durchführung eines erfindungsgemäßen Verfahrens zur Überwachung eines elektrisch beheizbaren Katalysators.

The invention is explained below in exemplary embodiments with reference to the accompanying drawings. The same components or components with the same function are identified by the same reference symbols in the different figures. Show it:

• 1 a first embodiment of an internal combustion engine with an exhaust system for performing a method according to the invention for monitoring an electrically heatable catalytic converter;
• 2 a further exemplary embodiment of an internal combustion engine with an exhaust system for carrying out a method according to the invention for monitoring an electrically heatable catalytic converter; and
• 3 a temperature profile on a temperature sensor in the exhaust system when performing a method according to the invention for monitoring an electrically heatable catalytic converter.

1 shows a schematic representation of an internal combustion engine 10 , its outlet 18th with an exhaust system 20th an exhaust gas aftertreatment system according to the invention for exhaust gas aftertreatment of an exhaust gas flow of the internal combustion engine 10 connected is. The internal combustion engine 10 is designed as a diesel engine. The internal combustion engine 10 has several combustion chambers 12th in which a fuel-air mixture is burned. This is on the combustion chambers 12th one fuel injector each 14th provided to a fuel in the combustion chambers 12th inject. The internal combustion engine 10 is preferably than by means of an exhaust gas turbocharger 24 supercharged combustion engine 10 running with a turbine 26th of the exhaust gas turbocharger 24 downstream of the outlet 18th and upstream of the exhaust aftertreatment components 28 , 30th , 32 , 34 , 36 , 38 , 46 is arranged. The exhaust system 20th includes an exhaust duct 22nd , in which in the flow direction of an exhaust gas through the exhaust gas duct 22nd downstream of the turbine 26th of the exhaust gas turbocharger 24 an electrically heated catalyst 28 and downstream of the electrically heatable catalyst 28 a preferably close-coupled catalyst 32 , especially an oxidation catalyst 34 or a NOx storage catalytic converter 36 , is arranged. Downstream of the oxidation catalyst 34 or the NOx storage catalytic converter 36 is an SCR catalytic converter 48 or a particle filter 42 arranged with a coating for the selective, catalytic reduction of nitrogen oxides. The electrically heated catalytic converter 28 includes an electrical heating element 30th , in particular an electric heating disk 44 , via which the downstream of the electrically heated catalyst 28 arranged exhaust aftertreatment components 32 , 34 , 36 , 38 , 46 essentially independent of the exhaust gas flow of the internal combustion engine 10 can be heated. The electrically heated catalytic converter 28 is with a control unit 50 of the internal combustion engine 10 connected, via which the heating power and / or the duration of the activation of the electrically heatable catalyst 28 can be controlled.

Downstream of the turbine 26th of the exhaust gas turbocharger 24 and upstream of the electrically heatable catalyst 28 is a temperature sensor 40 arranged, with which a temperature in the exhaust duct 22nd upstream of the electrically heatable catalyst 28 can be determined. The temperature sensor 40 is also with the control unit 50 connected and transmitted one in the exhaust duct 22nd measured temperature to the control unit 50 . Alternatively or additionally, it can also be upstream of the SCR catalytic converter 48 or the particle filter 42 an electrically heated catalyst 28 be arranged.

In 2 Figure 3 is an alternate embodiment of an exhaust system 20th for an internal combustion engine 10 shown. The internal combustion engine 10 is designed in this embodiment as a spark-ignition gasoline engine. The internal combustion engine 10 has at least one combustion chamber 12th on which a spark plug 16 for igniting a fuel-air mixture in the combustion chamber 12th is arranged. The internal combustion engine 10 is preferably a direct-injection internal combustion engine 10 executed. This is on the combustion chamber 12th a fuel injector 14th arranged with which a combustible fuel in the respective combustion chamber 12th can be injected. Alternatively or additionally, it can also be in the intake tract of the internal combustion engine 10 a fuel injection valve can be provided for introducing the combustible fuel.

The internal combustion engine 10 is with its outlet 18th with an exhaust system 20th connected, in which in the flow direction of an exhaust gas of the internal combustion engine 10 a turbine 26th of an exhaust gas turbocharger 24 and downstream of the turbine 26th , preferably as the first component for exhaust gas aftertreatment, an electrically heated catalytic converter 28 is arranged. The electrically heated catalytic converter 28 includes an electrical heating element 30th , in particular an electric heating disk 44 , with which the downstream of the electrically heated catalyst 28 arranged components for exhaust aftertreatment 32 , 34 , 36 , 38 , 42 , 46 , 48 , especially a three-way catalyst 38 or a four-way catalyst 46 essentially independent of the exhaust gas flow of the internal combustion engine 10 can be heated. The electrically heated catalytic converter 28 and / or the electrical heating element 30th are with a control unit 50 of the internal combustion engine 10 connected, via which the heating power and heating duration of the electrically heatable catalyst 28 and / or the electrical heating element 30th can be controlled.

Downstream of the first catalytic converter close to the engine 32 , 38 , 46 , preferably in an underbody position of a motor vehicle is a further catalytic converter 38 , 46 , especially another three-way catalyst 38 or another four-way catalyst 46 intended.

Downstream of the turbine 26th of the exhaust gas turbocharger 24 and upstream of the electrically heatable catalyst 28 is a temperature sensor 40 arranged, with which a temperature in the exhaust duct 22nd upstream of the electrically heatable catalyst 28 can be determined. The temperature sensor 40 is also with the control unit 50 connected and transmitted one in the exhaust duct 22nd measured temperature to the control unit 50 . Alternatively or additionally, upstream of the further catalyst can also be used 38 , 46 in the underbody position of the motor vehicle, an electrically heatable catalytic converter 28 be arranged.

Thanks to the electrically heated catalytic converter 28 can reduce emissions in the cold start phase of the internal combustion engine 10 and / or after the internal combustion engine has stopped 10 be reduced. This applies to internal combustion engines in motor vehicles as well as to stationary internal combustion engines. In particular, an electrically heatable catalyst 28 can also be used in a motor vehicle with a hybrid drive, since in such a motor vehicle the exhaust gas aftertreatment components can cool down below their operating temperature in purely electric driving mode. Such an electrically heatable catalyst 28 must be monitored by an on-board diagnosis, so that a functional restriction or a failure can be recognized, which would otherwise lead directly to an increase in tailpipe emissions. Due to the limited installation space and the additional costs, additional sensors should be used to monitor the electrically heated catalytic converter 28 dispensed with and already existing sensors 40 be used. The thermal radiation of the electrically heated catalytic converter 28 and / or the electrical heating element 30th leads to a measurable increase in temperature at the temperature sensor 40 upstream of the electrically heatable catalyst 28 . This rise in temperature can be used to analyze the heating power of the electrically heatable catalytic converter 28 be used. When the electrically heated catalytic converter is activated 28 such a temperature rise can be measured immediately, as there are no other components between the electrically heated catalytic converter 28 and the temperature sensor 40 need to be warmed through.

In 3 is the temperature profile on a directly upstream of the electrically heatable catalytic converter 28 arranged temperature sensor 40 depending on the activation of the electrically heated catalytic converter 28 shown. The electrical heating power ( P _H ), the temperature ( T _S ) on the temperature sensor 40 as well as the temperature ( T _nKat ) downstream of the catalyst 32 shown over time. How out 3 can be seen, there is a high correlation between the electrical heating output ( P _H ) and the temperature ( T _S ) on the temperature sensor 40 upstream of the electrically heatable catalyst 28 , which are used for monitoring and on-board diagnosis of the electrically heated catalytic converter 28 can be used.

List of reference symbols

10

Internal combustion engine

12th

Combustion chamber

14th

Fuel injector

16

spark plug

18th

Outlet

20th

Exhaust system

22nd

Exhaust duct

24

Exhaust gas turbocharger

26th

turbine

28

electrically heated catalytic converter

30th

electric heating element

32

catalyst

34

Oxidation catalyst

36

NOx storage catalytic converter

38

Three way catalytic converter

40

Temperature sensor

42

Particle filter

44

electric heating disc

46

Four way catalytic converter

48

SCR catalytic converter

50

Control unit

P _H

electrical heating power

P _def

defined heating power

Pmax

maximum heating power

T _S

Temperature at the temperature sensor

T _nKat

Temperature downstream of the catalyst

t

time

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102016122304 A1 [0006]
• DE 102017113320 A1 [0007]

Claims (10)

A method for monitoring an electrically heatable catalytic converter (28) in an exhaust system (20) of an internal combustion engine (10), a temperature sensor (40) being arranged in the exhaust system (20) upstream of the electrically heatable catalytic converter (28), comprising the following steps: - electrical heating of the electrically heatable catalyst (28), wherein - The temperature sensor (40) is heated by the thermal radiation of the electrically heatable catalyst (28), wherein - The temperature measured by the temperature sensor (40) is corrected for the cooling effect caused by the exhaust gas mass flow, wherein - As a result of the heating of the temperature sensor (40), a heat input from the electrically heatable catalytic converter (28) into the exhaust system (20) is determined. Method for monitoring an electrically heatable catalytic converter (28) according to Claim 1 , characterized in that the determined heating of the temperature sensor (40) is compared with a heating _{to be expected at a defined heating power (P def} ), and the functionality of the electrically heatable catalytic converter (28) is monitored on the basis of this comparison. Method for monitoring an electrically heatable catalytic converter (28) according to Claim 1 , characterized in that the determined heating gradient of the temperature sensor (40) is compared with a heating _{gradient to be expected at a defined heating power (P def} ), and the functionality of the electrically heatable catalytic converter (28) is monitored on the basis of this comparison . Method for monitoring an electrically heatable catalytic converter (28) according to Claim 2 or 3 , characterized in that the defined heating power (P _def ) is the maximum electrical heating power (P _max ) of the electrically heatable catalytic converter (28). Method for monitoring an electrically heatable catalytic converter (28) according to one of the Claims 1 to 4th , characterized in that the electrically heatable catalyst (28) is electrically heated for at least 15 seconds, the temperature change of the temperature sensor (40) being determined on the heat input. Method for monitoring an electrically heatable catalytic converter (28) according to one of the Claims 1 to 5 , characterized in that the electrically heatable catalyst (28) is electrically heated for at least five seconds, the gradient of the temperature change of the temperature sensor (40) being determined on the heat input. Exhaust system (20) for an internal combustion engine (10) with at least one combustion chamber (12), the internal combustion engine (10) being connectable with its outlet (18) to the exhaust system (20), with at least one catalytic converter (20) in the exhaust system (20). 32, 34, 36, 38, 42, 46, 48) and upstream of the catalytic converter (32, 34, 36, 38, 42, 46, 48) an electrically heatable catalytic converter (28) is arranged, with downstream of the outlet (18) and a temperature sensor (40) is arranged upstream of the electrically heatable catalytic converter (28), as well as with a control unit (50) which is set up to implement a method according to one of the Claims 1 to 4th to be carried out when a machine-readable program code is executed by the control device (50). Exhaust system (20) Claim 5 , characterized in that the electrically heatable catalyst (28) comprises an electrical heating element (30), in particular an electrical heating disk (44). Exhaust system (20) Claim 5 or 6th , characterized in that the catalytic converter (32, 34, 36, 38, 42, 46, 48) as an oxidation catalytic converter (34), as a NOx storage catalytic converter (36), as a three-way catalytic converter (38), as a four-way -Catalyst (46), as an SCR catalyst (48) or as a particle filter (42) with a catalytically active coating, in particular with a coating for the selective, catalytic reduction of nitrogen oxides. Exhaust system (20) according to one of the Claims 5 to 9 , characterized in that a turbine (26) of an exhaust gas turbocharger (24) is arranged in the exhaust system (20), the temperature sensor (40) being arranged downstream of the turbine (26) and upstream of the electrically heatable catalytic converter (28).

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