DE102016110632B4 - Process for regenerating a particulate filter - Google Patents

Abstract

Method for regenerating a particle filter (14) in the exhaust gas duct (12) of an internal combustion engine (10) with at least two separate combustion chambers (20, 22, 24, 26), with a close-coupled three-way catalytic converter (28) being installed in the exhaust gas duct (12). is arranged, which is downstream of a particle filter (14) in the underbody position of a motor vehicle, comprising the following steps:- operating the internal combustion engine (10) in a first operating state, with combustion in the combustion chambers (20, 22, 24, 26) of the internal combustion engine (10) the particles produced are stored in a particle filter (14) arranged in the exhaust gas duct (12), when a loading threshold 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 sub-stoichiometric combustion air ratio (λE<1) and a second combustion chamber (24) or a second group of combustion chambers (24, 26) with is operated with an over-stoichiometric air/fuel ratio (λE>1), and a stoichiometric air/fuel ratio is established overall in the exhaust gas duct (12) and the unburned components of the fuel from the first combustion chamber(s) (20) or first group of combustion chambers (20 , 22) with the residual oxygen from the second combustion chamber (24) or second group of combustion chambers (24, 26) operated with an over-stoichiometric combustion air ratio on a catalytic converter (28) upstream of the particle filter (14) until a threshold temperature (TS ) for regenerating the particle filter (14) is reached, and carrying out en an oxidation phase (III, V), in that the internal combustion engine (10) is operated with a superstoichiometric combustion air ratio (λE>1), the soot particles retained in the particle filter (14) being oxidized.

Description

The invention relates to a method for regenerating a particle filter in the exhaust gas duct of an internal combustion engine and a device for exhaust gas aftertreatment of an internal combustion engine, which is suitable for carrying out such a method.

The continuous tightening of the exhaust gas legislation places high demands on the vehicle manufacturers, which are solved by appropriate measures to reduce engine raw emissions and appropriate exhaust gas aftertreatment. With the introduction of the EU6 legislative stage, a limit value for a particle number is prescribed for petrol engines, which in many cases makes the use of a petrol particle filter necessary. Such an Otto particle filter is loaded with soot when driving. So that the exhaust back pressure does not increase too much, this Otto particle filter must be regenerated continuously or periodically. In order to thermally oxidize the soot retained in the Otto particle filter with oxygen, a sufficiently high temperature level in conjunction with the oxygen present at the same time in the exhaust system of the Otto engine is necessary. Since modern Otto engines are normally operated with a stoichiometric combustion air ratio (λ=1) without excess oxygen, additional measures are required. In addition, possible measures include, for example, increasing the temperature by adjusting the ignition angle, temporarily leaning the gasoline engine, blowing secondary air into the exhaust system, or a combination of these measures. Up to now, retarding the ignition angle in combination with lean adjustment of the Otto engine has been preferred, since this method does not require any additional components and can supply a sufficient quantity of oxygen at most operating points of the Otto engine.

From the DE 10 2010 039 013 A1 a method for regenerating a particle filter is known, with a three-way catalytic converter being arranged in an exhaust gas duct of an internal combustion engine downstream of a particle filter, with the oxidation of the soot retained in the particle filter being effected by a regeneration phase, and with the regeneration of the particle filter being carried out by a first, upstream of the particulate filter arranged lambda probe and a second, downstream of the three-way catalytic converter arranged lambda probe and upstream of the particulate filter arranged temperature sensor takes place. During the regeneration of the particle filter, a lambda value of λ=1 is regulated downstream of the three-way catalytic converter by means of a lambda control and the second lambda probe, which is arranged downstream of the three-way catalytic converter. This means that the three-way catalytic converter can achieve sufficient conversion of all harmful exhaust gas components during the regeneration of the particulate filter. The method can be used to detect the oxidation of soot on the particle filter, with oxygen consumption due to oxidation of the soot on the particle filter being determined directly or indirectly during the regeneration phase of the particle filter via the time profile of the signal from the first lambda probe compared to the signal from the second lambda probe can be. The disadvantage of the method, however, is that temperatures of at least 580° C. must be reached in order to oxidize soot, and this is not guaranteed in low part-load operation and when driving short distances.

From the DE 10 2009 028 237 A1 a method for monitoring the regeneration of a particle filter in the exhaust gas duct of an internal combustion engine is known, the particle filter being arranged in the exhaust gas duct upstream of a three-way catalytic converter, and the regeneration of the particle filter taking place by means of oxidative combustion in a regeneration phase of the particle filter. It is provided that during the regeneration phase the internal combustion engine is at least partially operated with a lean combustion mixture, with the oxidation of the soot on the particle filter being monitored by a first lambda probe arranged upstream of the particle filter and a second lambda probe arranged downstream of the three-way catalytic converter or is regulated. Here too, it is disadvantageous that no measures for heating in the exhaust gas duct known from the prior art are proposed, so that regeneration of the particle filter at low part-load operation and during short journeys cannot be guaranteed.

the EP 2 511 491 A1 discloses a method for regenerating a particle filter in the exhaust system of an internal combustion engine. It is provided that a first group of combustion chambers is operated with an over-stoichiometric combustion air ratio and a second group of combustion chambers is operated with a sub-stoichiometric combustion air ratio, with the unburned exhaust gas components being converted exothermically on the particulate filter in order to reduce the particulate filter to its original state retained soot to heat necessary regeneration temperature.

The object of the invention is now to provide a method for regenerating a particle filter in the exhaust gas duct of an internal combustion engine provide, which can also be carried out for short journeys or low part-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 according to the invention by a method for regenerating a particle filter in the exhaust gas duct of an internal combustion engine with at least two separate combustion chambers, which has the following steps:

• - Operating the internal combustion engine in a first operating state, with particles occurring during combustion in the combustion chambers of the internal combustion engine being stored in a particle filter arranged in the exhaust gas duct,
• - Determining a loading condition of the particulate filter arranged in the exhaust gas duct of the internal combustion engine and
• - Regenerate the particulate filter when a loading threshold is reached or exceeded, with the steps
  • - Carrying out a heating phase, in which the exhaust gas temperature of the internal combustion engine is raised by a first combustion chamber or a first group of combustion chambers of the internal combustion engine being operated with a sub-stoichiometric combustion air ratio and a second combustion chamber or a second group of combustion chambers being operated with a super-stoichiometric combustion air ratio, with overall, a stoichiometric combustion air ratio sets in the exhaust gas duct and the unburned components of the fuel from the first combustion chamber or first group of combustion chambers operated with a sub-stoichiometric combustion air ratio with the residual oxygen from the second combustion chamber or second group of combustion chambers operated with a super-stoichiometric combustion air ratio on the Particulate filter or a catalytic converter upstream of the particulate filter are implemented exothermically until a threshold temperature for regeneration of the Pa article filter is reached,
  • - Carrying out an oxidation phase by operating the internal combustion engine with a super-stoichiometric combustion air ratio, with the soot particles retained in the particle filter being oxidized.

The method according to the invention makes it 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 when driving short distances, and to carry out regeneration of the particle filter.

Advantageous improvements and further developments of the method for regenerating a particle filter specified in the independent claim are possible as a result of the measures specified in the dependent claims.

In a further preferred embodiment of the invention, it is provided that the regeneration of the particle filter is only initiated when a light-off temperature of the catalytic converter or the three-way catalytic coating of the particle filter has been reached. Below the light-off temperature of the catalytic converter or the three-way catalytic coating of the particle filter of approx. 250°C, no exothermic reaction can be started on the corresponding component in the exhaust gas duct, which would lead to a further increase in temperature.

A preferred embodiment of the method provides 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-friendly regeneration of the particle filter can be carried out without an uncontrolled increase in temperature on the particle filter occurring due to excessive soot burn-off on the particle filter.

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

It is particularly preferred if the lower threshold temperature is 580°C to 600°C and the upper threshold temperature is 650°C to 900°C. This can prevent both thermal damage to the particle filter and a drop in temperature well below the regeneration temperature.

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 is further leaned in the oxidation phase. The combustion air ratio during the heating phase is preferably in the range from 1.05 to 1.2, and in the oxidation phase preferably in the range from 1.1 to 1.4. This results in a total over-stoichiometric combustion air ratio Exhaust duct, whereby the soot particles retained on the soot filter can be oxidized. A mixture/air ratio of the first combustion chamber or the first group of combustion chambers operated with a rich mixture and the second combustion chamber operated with a lean mixture or the second group of combustion chambers operated with a lean mixture of 1.02 to 1.4 in the oxidation phase is particularly advantageous , on the one hand to provide enough oxygen for the oxidation of the soot retained in the particulate filter and on the other hand to avoid uncontrolled soot burn-off due to an excess of oxygen.

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. The rich mixture is set less rich, ie the combustion lambda is increased, with the corresponding combustion chamber or group of combustion chambers being operated with a 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 with a sub-stoichiometric combustion air ratio in the heating phase, is operated with a combustion air ratio of 0.85<λ _E <0.95. As a result, a sufficient number of unburned components of the fuel are fed into the exhaust duct to enable the particle filter to be heated to the regeneration temperature.

According to the invention, a device for exhaust gas aftertreatment of an internal combustion engine with at least two combustion chambers, in particular a gasoline engine, with an exhaust gas duct, a particle filter arranged in the exhaust gas duct, and a catalytic converter arranged in the exhaust gas duct is also proposed, with the particle filter preferably having a three-way catalytic coating, and the device is set up to carry out the method according to the invention.

Further preferred configurations of the invention result from the remaining features mentioned in the dependent claims.

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

• 1 ein Ausführungsbeispiel eines Verbrennungsmotors mit einem Abgaskanal und einer Vorrichtung zur Durchführung eines erfindungsgemäßen Verfahrens zur Regeneration eines Partikelfilters,
• 2 ein Diagramm zum zeitlichen Ablauf des Verfahrens zur Regeneration des Partikelfilters,
• 3 eine alternative Ausgestaltung eines Abgaskanals zur Durchführung eines erfindungsgemäßen Verfahrens zur Regeneration eines Partikelfilters,
• 4 eine weitere, alternative Ausführungsform eines Abgaskanals zur Durchführung eines erfindungsgemäßen Verfahrens, und
• 5 eine weitere, alternative Ausführungsform eines Abgaskanals zur Durchführung eines erfindungsgemäßen Verfahrens.

The invention is explained below in exemplary embodiments with reference to the associated drawings. Show it:

• 1 an embodiment of an internal combustion engine with an exhaust gas duct and a device for carrying out a method according to the invention for regenerating a particle filter,
• 2 a diagram of the timing of the procedure for regenerating the particle filter,
• 3 an alternative configuration of an exhaust gas duct for carrying out a method according to the invention for regenerating a particle filter,
• 4 a further, alternative embodiment of an exhaust gas duct for carrying out a method according to the invention, and
• 5 a further, alternative embodiment of an exhaust gas duct for carrying out a method according to the invention.

1 shows an internal combustion engine 10 with an exhaust gas duct 12. The internal combustion engine 10 is designed as a four-cylinder engine and has four combustion chambers 20, 22, 24, 26. A turbocharger 36 is arranged in the exhaust gas duct 12 downstream of an outlet 42 of the internal combustion engine 10 . A particle filter 14 is arranged downstream of the turbocharger 36 , which has a three-way catalytic coating 30 and is therefore designed as a four-way catalytic converter 16 . A further catalytic converter 28, preferably a three-way catalytic converter 18, is arranged downstream of the four-way catalytic converter 16 in the exhaust gas duct. The four-way catalytic converter 16 is preferably arranged close to the engine and the three-way catalytic converter 18 is preferably arranged under the floor of a motor vehicle. As a result, the four-way catalytic converter 16 can be heated up particularly quickly to a light-off temperature. An arrangement close to the engine is understood to mean an arrangement with a mean exhaust gas flow path of at most 50 cm, in particular at most 30 cm, after the outlet 42 of the internal combustion engine 10 . A first lambda probe 32 is arranged downstream of the turbocharger 36 and upstream of the four-way catalytic converter 16 . A second lambda probe 34 is arranged downstream of the four-way catalytic converter 16 . The lambda probes 32, 34 are connected via signal lines 40 to a control unit 38 of the internal combustion engine 10, via which the injected fuel quantity can be controlled or regulated individually for the individual combustion chambers 20, 22, 24, 26 of the internal combustion engine 10. As an alternative to an internal combustion engine 10 with four combustion chambers 20, 22, 24, 26, there are also others Embodiments of the internal combustion engine 10 with at least two separate combustion chambers 20, 24 are conceivable.

During operation of the internal combustion engine 10, as in 2 shown in a phase I (loading phase) of the particle filter 14 or the four-way catalytic converter 16 loaded with particles. If a specified threshold of the soot load on the particulate filter 14 or the four-way catalytic converter 16 is determined, which can be done, for example, by measuring the differential pressure across the particulate filter 14 or the four-way catalytic converter 16 or by a loading model, a regeneration process is initiated. For this purpose, the four-way catalytic converter 16 is heated to a regeneration temperature of at least 600° C. in a subsequent second phase II (heating phase). The particle filter 14 is heated by an exothermic conversion of unburned fuel components, in particular unburned hydrocarbons and carbon monoxide, directly on the three-way catalytic coating 30 of the four-way catalytic converter 16. A prerequisite for the exothermic conversion of the unburned fuel components is that a light-off temperature of the four-way catalytic converter 16 is reached. In order to then continue to heat the four-way catalytic converter 16 up to the regeneration temperature at which the soot retained in the four-way catalytic converter 16 can be oxidized, a combustion chamber-specific lambda adjustment takes place in the second phase II. In the internal combustion engine 10, two combustion chambers 20, 22 are operated with a rich, sub-stoichiometric combustion air ratio λ _E <1 and two further combustion chambers 24, 26 with a lean, over-stoichiometric combustion air ratio λ _E >1. It makes sense to operate the heating phase of the internal combustion engine 10 with as few emissions as possible. For this reason, it is desirable for a stoichiometric mixed lambda λ _M =1 to be established in the exhaust gas duct 12 downstream of the outlet 42 of the internal combustion engine 10 . As a result, the three-way functionality of the four-way catalytic converter 16 is ensured in the heating phase II and the pollutants in the exhaust gas can be converted into harmless exhaust gas components.

If the regeneration temperature for efficient soot conversion of the soot particles retained in the particulate filter 14 or in the four-way catalytic converter 16 has been reached, oxygen must be supplied to the exhaust gas duct 12 in a third phase III (oxidation phase) in order to break down the soot particles on the particulate filter 14 or the four-way Way catalyst 16 to oxidize. This can be achieved both by lambda adjustment of two combustion chambers 20, 22 or of all four combustion chambers 20, 22, 24, 26. In this case, either the two combustion chambers 24, 26 operated lean in the heating phase II can be further leaned, or the two combustion chambers 20, 22 operated rich in the heating phase II can be operated less richly. Alternatively, both measures in the combustion chambers 20, 22, 24, 26 can be combined. In all cases, the combustion limit and the smooth running of the internal combustion engine 10 and of the individual combustion chambers 20, 22, 24, 26 must be taken into account. When the rich-running combustion chambers 20, 22 are operated less richly, the heat output introduced into the four-way catalytic converter 16 is reduced. The measures described above lead to a super-stoichiometric mixed exhaust gas downstream of the outlet 42 , so that sufficient oxygen is available in the exhaust gas duct 12 for the oxidation of the soot particles retained in the four-way catalytic converter 16 . In order to ensure a controlled burn-off of the soot particles on the particle filter 14 or the four-way catalytic converter 16, the various options for lambda adjustment to achieve an over-stoichiometric mixed exhaust gas can be carried out continuously from the initial value to the desired target value. This can be done both linearly and progressively.

If the temperature at the particle filter 14 or at the four-way catalytic converter 16 falls below a lower threshold value T _SU of the four-way catalytic converter 16 during the oxidation phase III, it may be necessary for the oxidation phase III to be interrupted by a further heating phase IV got to. In this case, the particle filter 14 or the four-way catalytic converter 16 is preferably heated up to an upper threshold temperature T _SO of approximately 650°C. If the regeneration temperature of the four-way catalytic converter 16 is reached again, the oxidation of the soot particles can be continued in a new oxidation phase V, which corresponds to the implementation of the first oxidation phase III. If the particle filter 14 or the four-way catalytic converter 16 has been completely regenerated, which can also be determined by measuring the differential pressure or a loading model, the regeneration measure is completed and deactivated in a sixth step VI. Thereafter, the combustion chambers 20, 22, 24, 26 of the internal combustion engine 10 are again operated in a renewed charging phase I, each with a substantially stoichiometric combustion air ratio.

During the regeneration of the particle filter 14 or the four-way catalytic converter 16, in particular 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, with a high soot loading of the particle filter 14 or the four-way catalytic converter 16 and a simultaneously high exhaust gas temperature, the soot conversion can be minimized by reducing the oxygen, resulting in an effec tive component protection for the particle filter 14 or the four-way catalytic converter 16 is implemented. The method according to the invention for regenerating the particle filter is in 2 shown.

In 3 An alternative exemplary embodiment of an internal combustion engine 10 with an exhaust gas duct 12 is shown. With essentially the same structure as 1 shown, the exhaust gas duct 12 has only a four-way catalytic converter 16 and no further catalytic converters 18 , 28 . As an alternative or in addition, the turbocharger 36 in the exhaust gas duct 12 can also be omitted, since the method according to the invention is intended both for supercharged internal combustion engines 10 and for naturally aspirated engines.

In 4 a further, alternative exemplary embodiment of an internal combustion engine 10 with an exhaust gas duct 12 for carrying out a method according to the invention is shown. With essentially the same structure as 1 and 3 described, only the differences will be discussed below. Internal combustion engine 10 is designed as a two-cylinder engine, with a first combustion chamber 20 of internal combustion engine 10 being operated with a substoichiometric combustion air ratio and a second combustion chamber 24 with a superstoichiometric combustion air ratio during the regeneration process. In this exemplary embodiment, a three-way catalytic converter 28 close to the engine and a four-way catalytic converter 16 are provided in the underbody position of the motor vehicle. The exothermic conversion of the unburned fuel components takes place on the three-way catalytic converter 28, as a result of which the temperature at the three-way catalytic converter 28 and in the exhaust gas duct 12 downstream of the three-way catalytic converter 28 increases. Thus, due to the exothermic conversion of the unburned fuel components on the three-way catalytic converter 28, the exhaust gas temperature in the exhaust gas duct 12 can be increased in such a way that the regeneration temperature for burning off soot on the four-way catalytic converter 16 is also reached at the four-way catalytic converter 16 .

In 5 a further, alternative exemplary embodiment is shown. With essentially the same structure as 4 described, a particle filter 14 is arranged in the underbody position of the motor vehicle. The particle filter 14 can be uncoated or have a coating for the 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 being operated during the regeneration process with a sub-stoichiometric combustion air ratio and another combustion chamber 24 with a more than stoichiometric combustion air ratio.

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

Reference List

10

combustion engine

12

exhaust duct

14

particle filter

16

Four-way catalytic converter

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 catalytic converter

OPF

Otto particle filter

TWC

Three-way catalytic converter

λ

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

L

loading of the particle filter

T

Temperature at the particle filter

t

time

G

grams

I

liter

s

second

°C

Temperature in degrees Celsius

Claims (9)

Method for regenerating a particle filter (14) in the exhaust gas duct (12) of an internal combustion engine (10) with at least two separate combustion chambers (20, 22, 24, 26), with a close-coupled three-way catalytic converter (28) being installed in the exhaust gas duct (12). is arranged, which is downstream of a particle filter (14) in the underbody position of a motor vehicle, comprising the following steps: - Operating the internal combustion engine (10) in one first operating state, in which the particles produced during combustion in the combustion chambers (20, 22, 24, 26) of the internal combustion engine (10) are stored in a particle filter (14) arranged in the exhaust gas duct (12), - determining a loading state of the gas in the exhaust gas duct (12 ) the internal combustion engine (10) arranged particle filter (14), and - regenerating the particle filter (14) when a threshold value of the load is reached or exceeded, with - carrying out a heating phase (II, IV), wherein the exhaust gas temperature of the internal combustion engine (10) is raised by operating a first combustion chamber (20) or a first group of combustion chambers (20, 22) of the internal combustion engine (10) with a sub-stoichiometric combustion air ratio (λ _E <1) and a second combustion chamber (24) or a second group of Combustion chambers (24, 26) with a super-stoichiometric combustion air ratio (λ _E > 1) is operated, and with a total of a stoichiometric combustion air ratio in exhaust duct (12) and the unburned components of the fuel from the first combustion chamber (20) or first group of combustion chambers (20, 22) operated with a sub-stoichiometric combustion air ratio with the residual oxygen from the second combustion chamber (24) operated with a super-stoichiometric combustion air ratio or second group of combustion chambers (24, 26) are reacted exothermally on a catalytic converter (28) upstream of the particle filter (14) until a threshold temperature (T _S ) for regenerating the particle filter (14) is reached, and - carrying out an oxidation phase (III , V) in that the internal combustion engine (10) is operated with a superstoichiometric combustion air ratio (λ _E >1), the soot particles retained in the particle filter (14) being oxidized. procedure after claim 1 , characterized in that the regeneration of the particulate filter (14) is only initiated when a light-off temperature of the catalyst (28) is reached. procedure after claim 1 or 2 , 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 a lower threshold temperature (T _SU ) is reached will. procedure after claim 3 , 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) during the oxidation phase (III, V) below the lower threshold temperature (T _SU ) falls off. procedure after claim 4 , characterized in that the lower threshold temperature (T _SU ) is 580°C to 600°C and the upper threshold temperature (T _SO ) is 650°C to 900°C. Procedure according to one of Claims 1 until 5 , characterized in that the combustion air ratio of the second combustion chamber (24) or the second group of combustion chambers (24, 26) in the oxidation phase (III, V) is further leaned. Procedure according to one of Claims 1 until 6 , characterized in that during the oxidation phase (III, V) 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). Procedure according to one of Claims 1 until 7 , characterized in that in the heating phase (II, IV) 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 the aftertreatment of exhaust gas from an internal combustion engine (10), in particular a gasoline engine, with an exhaust gas duct (12), a particle filter (14) arranged in the exhaust gas duct (12), and a three-way catalytic converter (28) arranged close to the engine in the exhaust gas duct (12), which a particle filter (14) is connected downstream in the underbody position of a motor vehicle, the device for carrying out the method according to one of Claims 1 until 8th is trained.

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