DE102016110632A1 - Process for the regeneration of a particulate filter - Google Patents

Abstract

The invention relates to a method for the regeneration of a particulate filter in the exhaust passage of an internal combustion engine. In this case, the internal combustion engine has at least two combustion chambers, the particle filter initially being brought to a regeneration temperature for regeneration of the particle filter, the exhaust gas temperature of the internal combustion engine being raised in a heating phase by operating a first combustion chamber of the internal combustion engine with a substoichiometric combustion air ratio and a second combustion chamber Combustion chamber is operated with a superstoichiometric combustion air ratio. In the process, a stoichiometric combustion air ratio is set in the exhaust gas passage overall and the unburned constituents of the fuel from the combustion chamber operated with substoichiometric combustion air ratio with the residual oxygen from the combustion chamber operated with superstoichiometric combustion air ratio on a three-way catalytic coating of the particulate filter or a three-way catalytic converter upstream of the particulate filter. Catalyst exothermic reacted. In the regeneration phase, the internal combustion engine is then operated with a total superstoichiometric combustion air ratio in order to oxidize the soot particles retained in the particle filter. The invention further relates to a device for exhaust aftertreatment of an internal combustion engine with at least two separate combustion chambers, with which such a method can be performed.

Description

The invention relates to a method for the regeneration of a particulate filter in the exhaust passage of an internal combustion engine and to a device for the exhaust gas aftertreatment of an internal combustion engine which is suitable for carrying out such a method.

The continuous tightening of the exhaust emission legislation places high demands on the vehicle manufacturers, which are solved by appropriate measures for the reduction of the engine raw emissions and by a corresponding exhaust aftertreatment. With the introduction of the legislative level EU6, a limit value for gasoline engines is prescribed for a number of particles, which in many cases necessitates the use of an Otto particle filter. When driving, such a gasoline particulate filter is loaded with soot. So that the exhaust gas backpressure does not increase too much, this Otto particle filter must be regenerated continuously or periodically. In order to carry out a thermal oxidation of the soot retained in the Otto particle filter with oxygen, a sufficiently high temperature level in conjunction with simultaneously existing oxygen in the exhaust system of the gasoline engine is necessary. Since modern gasoline engines are normally operated without oxygen surplus with a stoichiometric combustion air ratio (λ = 1), additional measures are required. These come as measures, for example, a temperature increase by a Zündwinkelverstellung, a temporary lean adjustment of the gasoline engine, the injection of secondary air into the exhaust system or a combination of these measures in question. An ignition angle adjustment in the direction of late in combination with a lean adjustment of the gasoline engine is preferably used so far, since this method requires no additional components and can deliver a sufficient amount of oxygen in most operating points of the gasoline engine.

From the DE 10 2010 039 013 A1 is a method for the regeneration of a particulate filter is known, wherein in a exhaust passage of an internal combustion engine downstream of a particulate filter, a three-way catalyst is arranged, wherein the oxidation of the retained particulate in the soot is carried out by a regeneration phase, and wherein the regeneration of the particulate filter by a first, Lambda probe arranged upstream of the particle filter and a second lambda probe arranged downstream of the three-way catalytic converter and a temperature sensor arranged upstream of the particle filter are effected. During the regeneration of the particulate filter, it is provided that a lambda value of λ = 1 downstream of the three-way catalytic converter is adjusted by means of a lambda control and the second lambda probe, which is arranged downstream of the three-way catalytic converter. As a result, sufficient conversion through the three-way catalyst can be achieved during the regeneration of the particulate filter for all harmful exhaust gas components. By the method, the oxidation of soot can be detected on the particulate filter, during the regeneration phase of the particulate filter over the time course of the signal of the first lambda probe compared to the signal of the second lambda sensor directly or indirectly detected oxygen consumption by oxidation of the soot on the particulate filter can be. However, a disadvantage of the process is that temperatures of at least 580 ° C. must be reached for the oxidation of carbon black, and this is not ensured in a low part-load operation and in short-travel driving.

From the DE 10 2009 028 237 A1 a method for monitoring the regeneration of a particulate filter in the exhaust passage of an internal combustion engine is known, wherein the particulate filter is disposed in the exhaust passage upstream of a three-way catalyst, and wherein the regeneration of the particulate filter is carried out by an oxidative combustion in a regeneration phase of the particulate filter. It is provided that during the regeneration phase of the internal combustion engine is operated at least partially with a lean combustion mixture, wherein the oxidation of the soot on the particulate filter by a first, arranged upstream of the particulate filter lambda probe and a second, downstream of the three-way catalytic converter arranged lambda sensor monitors or regulated. Another disadvantage here is that none of the known from the prior art measures for heating in the exhaust duct are proposed so that a regeneration of the particulate filter at low partial load operation and short-haul driving can not be guaranteed.

The invention is based on the object of providing a method for regeneration of a particulate filter in the exhaust passage of an internal combustion engine, which can also be carried out during short journeys or low partial load operation and which overcomes the disadvantages known from the prior art.

• – Betreiben des Verbrennungsmotors in einem ersten Betriebszustand, wobei bei der Verbrennung in den Brennräumen des Verbrennungsmotors entstehende Partikel in einem im Abgaskanal angeordneten Partikelfilter eingelagert werden,
• – Ermitteln eines Beladungszustandes des im Abgaskanal der Brennkraftmaschine angeordneten Partikelfilters und
• – Regenerieren des Partikelfilters, wenn ein Schwellenwert der Beladung erreicht oder überschritten ist, mit den Schritten – Durchführen einer Heizphase, wobei die Abgastemperatur des Verbrennungsmotors angehoben wird, indem ein erster Brennraum oder eine erste Gruppe von Brennräumen des Verbrennungsmotors mit einem unterstöchiometrischen Verbrennungsluftverhältnis betrieben wird und ein zweiter Brennraum oder eine zweite Gruppe von Brennräumen mit einem überstöchiometrischen Verbrennungsluftverhältnis betrieben wird, wobei sich insgesamt ein stöchiometrisches Verbrennungsluftverhältnis im Abgaskanal einstellt und die unverbrannten Bestandteile des Kraftstoffs aus dem bzw. der mit unterstöchiometrischem Verbrennungsluftverhältnis betriebenen ersten Brennraum oder ersten Gruppe von Brennräumen mit dem Restsauerstoff aus dem bzw. der mit überstöchiometrischem Verbrennungsluftverhältnis betriebenen zweiten Brennraum oder zweiten Gruppe von Brennräumen auf dem Partikelfilter oder einem dem Partikelfilter vorgeschalteten Katalysator exotherm umgesetzt werden, bis eine Schwellentemperatur zur Regeneration des Partikelfilters erreicht ist, – Durchführen einer Oxidationsphase, indem der Verbrennungsmotor mit einem überstöchiometrischen Verbrennungsluftverhältnis betrieben wird, wobei die im Partikelfilter zurückgehaltenen Rußpartikel oxidiert werden.

The object is achieved by a method for the regeneration of a particulate filter in the exhaust passage of an internal combustion engine with at least two separate combustion chambers, which comprises the following steps:

• Operating the internal combustion engine in a first operating state, wherein particles formed during combustion in the combustion chambers of the internal combustion engine are stored in a particle filter arranged in the exhaust gas duct,
• - Determining a loading state of the arranged in the exhaust passage of the internal combustion engine particulate filter and
• Regenerating the particulate filter when a threshold value of the load is reached or exceeded, comprising the steps of - performing a heating phase wherein the exhaust gas temperature of the internal combustion engine is increased by operating a first combustion chamber or a first group of combustion chambers of the internal combustion engine with a substoichiometric combustion air ratio and a second combustion chamber or a second group of combustion chambers is operated with a superstoichiometric combustion air ratio, wherein a stoichiometric combustion air ratio sets in the exhaust passage and the unburned components of the fuel from the or the stoichiometric combustion air ratio operated first combustion chamber or first group of combustion chambers with the residual oxygen from the or with the superstoichiometric combustion air ratio operated second combustion chamber or second group of combustion chambers on the particles - Performing an oxidation phase in which the internal combustion engine is operated with a superstoichiometric combustion air ratio, wherein the particulate matter retained in the particulate filter soot particles are oxidized - performing an oxidation phase exothermically reacted to a threshold temperature for regeneration of the particulate filter.

By means of the method according to the invention, it is possible to raise the temperature in the exhaust gas duct in order to heat the particle filter to a regeneration temperature even at low partial load or short-distance travel, and to carry out regeneration of the particle filter.

The measures specified in the dependent claims advantageous improvements and developments of the method specified in the independent claim for the regeneration of a particulate filter are possible.

In a preferred embodiment of the invention it is provided that the particulate filter has a three-way catalytic coating, wherein the unburned constituents of the fuel are exothermically reacted on the three-way catalytic coating of the particulate filter.

As a result, a direct heating of the particulate filter by the exothermic reaction on the coating is possible, whereby a particularly simple and rapid heating of the particulate filter to the regeneration temperature is possible.

In a further preferred embodiment of the invention it is provided that the regeneration of the particulate filter is initiated only when a light-off temperature of the catalyst or the three-way catalytic coating of the particulate filter is reached. Below the light-off temperature of the catalyst or the three-way catalytic coating of the particulate filter of about 250 ° C, no exothermic reaction can be started on the corresponding component in the exhaust gas channel, which leads to a further increase in temperature.

In a preferred embodiment of the method it is provided that the heating phase is maintained until an upper threshold temperature is reached, and the oxidation phase of the particulate filter is maintained until a lower threshold temperature is reached. As a result, a component-sparing regeneration of the particulate filter can be carried out without excessive carbon black burning off on the particulate filter leading to an uncontrolled rise in temperature on the particulate filter.

According to an improvement of the method it is provided that a renewed heating phase is initiated when the particulate filter is not completely regenerated and the temperature at the particulate filter drops below the lower threshold temperature during the oxidation phase. As a result, a multi-stage regeneration of the particulate filter is possible, it being possible to start at a high temperature level when the particulate filter is reheated, and the heating phase can be correspondingly shorter.

It is particularly preferred if the lower threshold temperature at 580 ° C to 600 ° C and the upper threshold temperature at 650 ° C to 900 ° C. As a result, both a thermal damage to the particulate filter and a drop in temperature far below the regeneration temperature can be prevented.

According to a further improvement of the method, it is provided that the combustion air ratio of the second combustion chamber or the second group of combustion chambers in the oxidation phase is further emaciated. In this case, the combustion air ratio is preferably in the range of 1.05 to 1.2 during the heating phase, and preferably in the range of 1.1 to 1.4 in the oxidation phase. This results in a total superstoichiometric combustion air ratio in the exhaust passage, whereby an oxidation of the soot particles retained on the soot filter can take place. Here, a mixture air ratio of the operated with rich mixture first combustion chamber or the first group of combustion chambers and operated with a lean mixture second combustion chamber or with lean mixture operated second group of combustion chambers from 1.02 to 1.4 in the oxidation phase particularly advantageous to provide on the one hand sufficient oxygen for the oxidation of retained in the particulate filter soot and on the other hand to avoid uncontrolled Rußabbrand by excessive oxygen excess.

According to a further improvement of the method, it is provided that during the oxidation phase the first combustion chamber or the first group of combustion chambers is operated with a less rich combustion air ratio than in the heating phase. In this case, the rich mixture is set to less rich, that is, the combustion lambda increased, wherein the corresponding combustion chamber or the group of combustion chambers is operated with a still slightly rich mixture, a stoichiometric combustion air ratio or with a lean combustion air ratio. The ignition limits of the combustion mixture in the combustion chamber must be observed.

According to a further development of the method, it is provided that in the heating phase the first combustion chamber or the first group of combustion chambers, which are operated in the heating phase with a substoichiometric combustion air ratio, is operated with a combustion air ratio of 0.85 <λ _E <0.95. As a result, a sufficient number of unburned constituents of the fuel are introduced into the exhaust gas channel in order to allow the particle filter to be heated up to the regeneration temperature.

According to the invention, a device for exhaust aftertreatment of an internal combustion engine having at least two combustion chambers, in particular a gasoline engine, with an exhaust passage, a particulate filter arranged in the exhaust duct, and a catalyst arranged in the exhaust duct is also proposed, wherein the particulate filter preferably has a three-way catalytic coating, and the device is designed for carrying out the method according to the invention.

Further preferred embodiments of the invention will become apparent from the remaining, mentioned in the dependent claims characteristics.

The various embodiments of the invention mentioned in this application are, unless otherwise stated in the individual case, advantageously combinable with each other.

The invention will be explained below in embodiments with reference to the accompanying drawings. Show it:

1 An embodiment of an internal combustion engine with an exhaust passage and an apparatus for carrying out a method according to the invention for the regeneration of a particulate filter,

2 a diagram of the timing of the method for the regeneration of the particulate filter,

3 an alternative embodiment of an exhaust gas duct for carrying out a method according to the invention for the regeneration of a particulate filter,

4 a further alternative embodiment of an exhaust passage for performing a method according to the invention, and

5 a further alternative embodiment of an exhaust passage for performing a method according to the invention.

1 shows an internal combustion engine 10 with an exhaust duct 12 , The internal combustion engine 10 is designed as a four-cylinder engine and has four combustion chambers 20 . 22 . 24 . 26 on. Downstream of an outlet 42 of the internal combustion engine 10 is in the exhaust duct 12 a turbocharger 36 arranged. Downstream of the turbocharger 36 is a particle filter 14 arranged, which is a three-way catalytic coating 30 carries and thus as a four-way catalyst 16 is trained. Downstream of the four-way catalyst 16 is another catalyst in the exhaust duct 28 , preferably a three-way catalyst 18 arranged. This is the four-way catalyst 16 preferably close to the engine and the three-way catalyst 18 preferably arranged in the bottom layer of a motor vehicle. This is a particularly rapid heating of the four-way catalyst 16 possible up to a light-off temperature. Under a close-coupled arrangement is an arrangement with a mean Abgaslaufweg of at most 50 cm, in particular of the highest 30 cm, after the outlet 42 of the internal combustion engine 10 Understood. Downstream of the turbocharger 36 and upstream of the four-way catalyst 16 is a first lambda probe 32 arranged. Downstream of the four-way catalyst 16 is a second lambda probe 34 arranged. The lambda probes 32 . 34 are via signal lines 40 with a control unit 38 of the internal combustion engine 10 connected, via which the injection amount of fuel individually for the individual combustion chambers 20 . 22 . 24 . 26 of the internal combustion engine 10 can be controlled or regulated. Alternative to an internal combustion engine 10 with four combustion chambers 20 . 22 . 24 . 26 are also other embodiments of the internal combustion engine 10 with at least two separate combustion chambers 20 . 24 conceivable.

In operation of the internal combustion engine 10 will be like in 2 represented in a phase I (loading phase) of the particulate filter 14 or the four-way catalyst 16 loaded with particles. Will set a specified threshold of soot loading on the particulate filter 14 or the four-way catalyst 16 determined, for example, by a differential pressure measurement via the particulate filter 14 or via the four-way catalyst 16 or by a loading model, a regeneration process is initiated. This is done in a subsequent second phase II (heating phase) of the four-way catalyst 16 heated to a regeneration temperature of at least 600 ° C. The heating of the particle filter 14 is carried out by an exothermic reaction of unburned fuel components, especially unburned hydrocarbons and carbon monoxide, directly on the three-way catalytic coating 30 of the four-way catalyst 16 , The prerequisite for the exothermic conversion of unburned fuel components is that a light-off temperature of the four-way catalyst 16 is reached. To the four-way catalyst 16 then continue to heat up to the regeneration temperature at which in the four-way catalyst 16 retained soot can be oxidized, takes place in the second phase II a combustion chamber individual lambda adjustment. It will be in the internal combustion engine 10 two combustion chambers each 20 . 22 with a rich, substoichiometric combustion air ratio λ _E <1 and two additional combustion chambers 24 . 26 operated with a lean, superstoichiometric combustion air ratio λ _E > 1. It makes sense, the heating phase of the internal combustion engine 10 operate as emission neutral as possible. For this reason, it is desirable that downstream of the outlet 42 of the internal combustion engine 10 a stoichiometric Mischlambda λ _M = 1 in the exhaust duct 12 established. As a result, in the heating phase II, the three-way functionality of the four-way catalyst 16 ensured and the pollutants in the exhaust gas can be converted into harmless exhaust gas components.

Is the regeneration temperature for efficient soot conversion that in the particulate filter 14 or in the four-way catalyst 16 retained soot particles, must the exhaust duct 12 in a third phase III (oxidation phase) oxygen are supplied to the soot particles on the particulate filter 14 or the four-way catalyst 16 to oxidize. This can be achieved by a lambda adjustment of two combustion chambers 20 . 22 or from all four combustion chambers 20 . 22 . 24 . 26 be achieved. In this case, either the two in the heating phase II lean burned combustion chambers 24 . 26 be further emaciated or the two burned in the heating phase II burning chambers 20 . 22 be operated less fat. Alternatively, both measures in the combustion chambers 20 . 22 . 24 . 26 be combined. In all cases, the combustion limit and the smoothness of the internal combustion engine 10 as well as the individual combustion chambers 20 . 22 . 24 . 26 to take into account. If the fat burning combustion chambers 20 . 22 Being operated less fat, which is in the four-way catalyst 16 introduced heating power reduced. The measures described above lead to a downstream of the outlet 42 superstoichiometric mixed exhaust gas, so that sufficient oxygen for the oxidation of the four-way catalyst 16 retained soot particles in the exhaust duct 12 is available. To a controlled burnup of soot particles on the particulate filter 14 or the four-way catalyst 16 to ensure that the various possibilities of lambda adjustment to achieve a superstoichiometric mixed exhaust gas continuously from the initial value to the desired target value can be performed. This can be done both linearly and progressively.

Should the temperature on the particle filter 14 or on the four-way catalyst 16 during the oxidation phase III below a lower threshold T _{SU of} the four-way catalyst 16 fall off, it may be necessary that the oxidation phase III must be interrupted by another heating phase IV. This is the particle filter 14 or the four-way catalyst 16 preferably heated up to an upper threshold temperature T _SO of about 650 ° C. Is the regeneration temperature of the four-way catalyst 16 Once again reached, in a renewed oxidation phase V, which corresponds to their implementation of the first oxidation phase III, the oxidation of the carbon black particles can be continued. Is the particle filter 14 or the four-way catalyst 16 completely regenerated, which can also be determined by a differential pressure measurement or a loading model, the regeneration measure is completed and deactivated in a sixth step VI. After that, the combustion chambers 20 . 22 . 24 . 26 of the internal combustion engine 10 again in a renewed loading phase I each operated with a substantially stoichiometric combustion air ratio.

During the regeneration of the particulate filter 14 or the four-way catalyst 16 , Especially during the oxidation phases III, V, it is possible to control the maximum soot conversion by adjusting the residual oxygen content. As a result, for example, at a high soot loading of the particulate filter 14 or the four-way catalyst 16 and a simultaneously high exhaust gas temperature of the soot conversion can be minimized by a reduction of the oxygen, whereby an effective component protection for the particulate filter 14 or the four-way catalyst 16 is realized. The inventive method for the regeneration of the particulate filter is in 2 shown.

In 3 is an alternative embodiment of an internal combustion engine 10 with an exhaust duct 12 for carrying out a method according to the invention. With essentially the same structure as 1 shown, the exhaust duct 12 only a four-way catalyst 16 and no other catalysts 18 . 28 on. Alternatively or additionally, the turbocharger can also 36 in the exhaust duct 12 omitted, since the inventive method both for supercharged internal combustion engines 10 as well as for naturally aspirated engines is provided.

In 4 is another alternative embodiment of an internal combustion engine 10 with an exhaust duct 12 for carrying out a method according to the invention. With essentially the same structure as 1 and 3 will be described below, only the differences. The internal combustion engine 10 is designed as a two-cylinder engine, wherein during the process for regeneration a first combustion chamber 20 of the internal combustion engine 10 with a substoichiometric combustion air ratio and a second combustion chamber 24 is operated with a superstoichiometric combustion air ratio. In this embodiment, a close-coupled three-way catalyst 28 and a four-way catalyst 16 provided in underfloor position of the motor vehicle. In this case, the exothermic reaction of the unburned fuel components takes place on the three-way catalyst 28 , which raises the temperature at the three-way catalyst 28 and in the exhaust duct 12 downstream of the three-way catalyst 28 elevated. Thus, by the exothermic reaction of the unburned fuel components on the three-way catalyst 28 the exhaust gas temperature in the exhaust duct 12 be increased so that the four-way catalyst 16 the regeneration temperature for a Rußabbrand on the four-way catalyst 16 is reached.

In 5 is shown a further alternative embodiment. With essentially the same structure as 4 is described in Unterbodenlage of the motor vehicle, a particulate filter 14 arranged. The particle filter 14 may be uncoated or have a coating for selective catalytic reduction of nitrogen oxides. The internal combustion engine 10 is designed as a three-cylinder engine, with a group of combustion chambers 20 . 22 during the regeneration process with a substoichiometric combustion air ratio and another combustion chamber 24 is operated with a superstoichiometric combustion air ratio.

The various embodiments of the invention mentioned in this application are, unless otherwise stated in the individual case, advantageously combinable with each other.

LIST OF REFERENCE NUMBERS

10

internal combustion engine

12

exhaust duct

14

particulate Filter

16

Four-way catalyst

18

Three-way catalytic converter

20

first combustion chamber

22

third combustion chamber

24

second combustion chamber

26

fourth combustion chamber

28

catalyst

30

three-way catalytic coating

32

first lambda probe

34

second lambda probe

36

turbocharger

38

control unit

40

signal lines

FWC

Four-way catalyst

OPF

Otto particulate filter

TWC

Three-way catalytic converter

λ

Combustion air ratio in the exhaust duct upstream of the particulate filter

L

Loading the particle filter

T

Temperature at the particle filter

t

Time

G

gram

l

liter

s

second

° C

Temperature in degrees Celsius

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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.

Cited patent literature

• DE 102010039013 A1 [0003]
• DE 102009028237 A1 [0004]

Claims (10)

Process for the regeneration of a particulate filter ( 14 ) in the exhaust duct ( 12 ) of an internal combustion engine ( 10 ) with at least two separate combustion chambers ( 20 . 22 . 24 . 26 ), comprising the following steps: - operating the internal combustion engine ( 10 ) in a first operating state, wherein during combustion in the combustion chambers ( 20 . 22 . 24 . 26 ) of the internal combustion engine ( 10 ) resulting particles in a in the exhaust channel ( 12 ) arranged particulate filter ( 14 ), - determining a loading state of the in the exhaust duct ( 12 ) of the internal combustion engine ( 10 ) arranged particulate filter ( 14 ), and - regeneration of the particulate filter ( 14 ), when a threshold value of the load is reached or exceeded, with - performing a heating phase (II, IV), wherein the exhaust gas temperature of the internal combustion engine ( 10 ) is raised by a first combustion chamber ( 20 ) or a first group of combustion chambers ( 20 . 22 ) of the internal combustion engine ( 10 ) is operated with a substoichiometric combustion air ratio (λ _E <1) and a second combustion chamber ( 24 ) or a second group of combustion chambers ( 24 . 26 ) is operated with a superstoichiometric combustion air ratio (λ _E > 1), and wherein a total of a stoichiometric combustion air ratio in the exhaust gas channel ( 12 ) and the unburned constituents of the fuel from the first combustion chamber (s) operated with a substoichiometric combustion air ratio ( 20 ) or first group of combustion chambers ( 20 . 22 ) with the residual oxygen from the second combustion chamber operated with a superstoichiometric combustion air ratio ( 24 ) or second group of combustion chambers ( 24 . 26 ) on the particulate filter ( 14 ) or one of the particulate filters ( 14 ) upstream catalyst ( 28 ) are exothermically reacted until a threshold temperature (T _S ) for regeneration of the particulate filter ( 14 ), and - performing an oxidation phase (III, V) by the internal combustion engine ( 10 ) is operated with a superstoichiometric combustion air ratio (λ _E > 1), wherein the in the particulate filter ( 14 ) are retarded soot particles are oxidized. Method according to claim 1, characterized in that the particle filter ( 14 ) a three-way catalytic coating ( 30 ), wherein the unburned constituents of the fuel on the three-way catalytic coating ( 30 ) of the particulate filter ( 14 ) are exothermically reacted. Method according to one of claims 1 or 2, characterized in that the regeneration of the particulate filter ( 14 ) is initiated only when a light-off temperature of the catalyst ( 28 ) or the three-way catalytic coating ( 30 ) of the particulate filter ( 14 ) is reached. Method according to one of claims 1 to 3, characterized in that the heating phase (II, IV) is maintained until an upper threshold temperature (T _SO ) is reached, and the oxidation phase (III, V) is maintained until, until a lower threshold temperature (T _SU ) is reached. A method according to claim 4, characterized in that a renewed heating phase (II, IV) is initiated when the particulate filter ( 14 ) is not fully regenerated and the temperature at the particulate filter ( 14 ) falls below the lower threshold temperature (T _SU ) during the oxidation phase (III, V). A method according to claim 5, characterized in that the lower threshold temperature (T _SU ) at 580 ° C to 600 ° C and the upper threshold temperature (T _SO ) at 650 ° C to 900 ° C. Method according to one of claims 1 to 6, characterized in that the combustion air ratio of the second combustion chamber ( 24 ) or the second group of combustion chambers ( 24 . 26 ) is further emaciated in the oxidation phase (III, V). Method according to one of claims 1 to 7, characterized in that during the oxidation phase (III, V) of the first combustion chamber ( 20 ) or the first group of combustion chambers ( 20 . 22 ) is operated with a less rich combustion air ratio than in the heating phase (II, IV). Method according to one of claims 1 to 8, characterized in that in the heating phase (II, IV) of the first combustion chamber ( 20 ) or the first group of combustion chambers ( 20 . 22 ) is operated with a combustion air ratio of 0.85 <λ _E <0.95. Device for exhaust aftertreatment of an internal combustion engine ( 10 ), in particular a gasoline engine, with an exhaust gas duct ( 12 ), one in the exhaust duct ( 12 ) arranged particulate filter ( 14 ), and one in the exhaust duct ( 12 ) arranged catalyst ( 28 ), the particle filter ( 14 ) preferably a three-way catalytic coating ( 30 ) and the device for carrying out the method according to one of claims 1 to 9 is formed.

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