PARTICLE FILTER FOR AN INTERNAL COMBUSTION ENGINE

A particle filter for an internal combustion engine has a filter body (2) with a first channel (5) having a first end (7) facing a filter inlet (3) and a second end (8) facing a filter outlet (4), and a flow-through second channel (6) having a third end (9) facing the filter inlet (3) and a fourth end (10) formed facing the filter outlet (4). The second and third ends (8, 9) cannot accommodate flow therethrough. The channels (5, 6) are divided into a flow-through section (13) and a non-flow-through section (14). A wall (11) between the channels (5, 6) enables soot particles to be separated from exhaust gas flowing through the filter body (2) from the first channel (5) into the second channel (6). The non-flow-through channel section (14) has a heating element (15) to increase a reaction temperature in the filter (1) for burning off the soot particles.

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Description
BACKGROUND Field of the Invention

The invention relates to a particle filter for an internal combustion engine.

Related Art

Particle filters for internal combustion engines, in particular for spontaneous-ignition internal combustion engines, are known. The particle filter is distinguished in particular in that a plurality of ducts are disposed beside one another, in particular parallel with one another, wherein the ducts are closed in an alternating manner. The exhaust gas that flows in by way of a filter inlet flows through the particle filter in the direction of the extent of the latter in that said exhaust gas from an open duct at the filter inlet enters an open duct at the filter outlet by way of a porous wall that is disposed between said two ducts. Solid particles of the exhaust gas are deposited in and/or on the wall. Since said particles reduce an available flow cross section of the particle filter, and because the potential for excessive temperature increases in the particle filter as a result of an exothermic burn-off of soot increases as the loading increases, said particles are to be removed from the particle filter by way of a so-called regeneration, in other words by converting the soot particles.

A particle filter for an internal combustion engine can be derived from patent document EP 2 161 420 B1, said particle filter being non-coated in regions of the ducts in which predominantly solid particles are deposited. In each case one coated portion and one non-coated portion are thus configured in the ducts, wherein the non-coated portion of one duct is configured so as to neighbor the coated portion of a further duct.

A particle filter for an internal combustion engine configured as a diesel engine is disclosed in the first and unexamined publication EP 1 250 952 A1, said particle filter for the oxidation of soot having a coating, the reaction temperature of said coating being below 500° C. This is achieved with the aid of preferred materials of the particle filter in the form of alkaline earth metal compounds, a substance that stores oxygen, and platinum, palladium, or rhodium.

Patent document U.S. Pat. No. 7,691,339 B2 discloses a particle filter for an internal combustion engine, said particle filter for reducing the soot particles that are deposited in the particle filter utilizing microwave energy. A microwave generator which heats microwave-absorbing material that is received in the soot filter is provided herein.

A particle filter which has a functional material coating can be derived from the first and unexamined publication DE 10 2006 032 886 A1. The ducts of the particle filter that are to be passed by a flow are coated with the functional material on the wall surfaces of said ducts, wherein the functional material in an exothermic reaction, proceeding from a first modification, transitions to a second modification, this leading to an increase in a temperature present in the particle filter.

It is the object of the present invention to provide an improved particle filter for an internal combustion engine.

SUMMARY

A particle filter according to the invention for an internal combustion engine has a filter body, wherein the filter body has a filter inlet passable by a flow, and a filter outlet passable by a flow. The filter body comprises at least one first duct passable by a flow, having a first end that is configured so as to face the filter inlet, and a second end that is configured so as to face the filter outlet, and a second duct passable by a flow, having a third end that is configured so as to face the filter inlet, and a fourth end that is configured so as to face the filter outlet. The second end and the third end are configured so as to be impassable by a flow, or in a certain manner so as to be difficult to be passed by a flow, on account of which the ducts are capable of being divided into a duct portion passable by a flow and a duct portion impassable by flow or in a certain manner difficult to be passed by a flow.

On account thereof, first ducts having a blocked or impeded flow inlet at the filter inlet and second ducts having a blocked or impeded flow outlet at the filter outlet are configured. A flow transfer of an exhaust gas flowing through the particle filter proceeding from the first duct to the second duct is performed by way of a common duct wall that is configured between the first duct and the second duct. The duct wall is configured so as to be capable of separating soot particles of the exhaust gas.

A duct portion impassable by a flow hereunder is not necessarily to be understood as a completely sealed duct portion that is closed in relation to any capability of being passed by a flow, but is also to be understood to be a duct portion that in a certain manner is difficult to be passed by a flow, for example a so-called diffusible duct portion, wherein oxygen molecules can in particular penetrate this duct portion that is difficult to be passed by a flow.

The first duct and/or the second duct for increasing a reaction temperature present in the particle filter for burning off the soot particles have/has a heating element, wherein the heating element is disposed in that duct portion of the duct that is impassable by a flow.

The disposal of the heating element in the duct portion impassable by the a flow has a plurality of advantages. A flow passing the particle filter is thus not impeded by virtue of the heating element which has a flow resistance, for example. A further advantage is to be seen in utilizing those regions of the particle filter that in terms of being passed by a flow are not utilized: an increase in the reaction temperature for burning off the soot particles can be achieved while maintaining the original size of the particle filter. In other words, this means that a provided installation space of the particle filter is maintained and no constructive modification measures have to be carried out in terms of the installation space. In as far as the ducts of the particle filter are coated, for example, this can result in a duct cross section of the duct by virtue of the coating being reduced as compared to non-coated ducts. However, the duct cross section of the particle filter is to be increased in order for flow conditions that correspond to the non-coated particle filter to be able to be achieved by the particle filter having the coating, on account of which the required installation space of the particle filter having the coating is likewise increased.

In one design embodiment of the particle filter according to the invention the heating element is configured from a functional material which reacts in an exothermic manner when storing oxygen. In other words, this means that the heating element is configured so as to be quasi spontaneously igniting. The advantage is to be seen in that only the heating element per se is required, without providing, for example, an auxiliary means in the form of an ignition device such as, for example, the microwave generator, as is known in the prior art. The operation of the internal combustion machine has only to be adapted such that the exothermic reaction of the functional material is initiated by virtue of a corresponding temperature of the exhaust gas and/or a corresponding composition of the exhaust gas.

The heating element for the release of heat is preferably excitable with the aid of a modification of a combustion air ratio. To this end, the combustion air ratio of the exhaust gas can be modified by adding or reducing fuel or air. In particular, a so-called sub-stoichiometric composition which corresponds to a combustion air ratio having a value below 1, or a super-stoichiometric composition which corresponds to a combustion air ratio having a value above 1, is thus achievable by way of a so-called rich operation of the internal combustion engine machine or a lean operation of the internal combustion machine.

The heating element for the release of heat is preferably excitable with the aid of a modification of a combustion air ratio of the exhaust gas from a combustion air ratio having a value below 1 to a combustion air ratio having a value above 1. This modification of the combustion air ratio can be achieved, for example, proceeding from a load operation of the internal combustion engine in the event of an even only sub-stoichiometric operation, for example at a value of the combustion air ratio of approx. 0.98 and in the event of a subsequent overrun operation of the internal combustion engine, in particular by way of an overrun cut-off.

An operation of this type of the internal combustion engine can be obtained, for example, already by a downhill travel or a deceleration of a motor vehicle by way of the internal combustion engine. On account thereof, a temperature increase by virtue of the heat release by the heating element in the particle filter is capable of being initiated already in the event of a brief overrun operation that can be realized, for example by virtue of the downhill travel or a deceleration, in particular by way of an overrun cut-off. In other words, the heating element can react with a vehement temperature increase to a brief lean operation of the internal combustion engine, for example by way of an overrun cut-off. The advantage is that an engine control unit if at all has to be adapted only slightly to the operation of the internal combustion engine.

In one further design embodiment of the particle filter according to the invention the heating element has an element cross section which corresponds to a cross section of the duct. The heating element, apart from the temperature-increasing function thereof, can be utilized for sealing the duct in a unilateral manner.

The heating element is preferably configured so as to be based at least on cerium oxide and/or cerium-zirconium mixed oxides. Said oxides, given a corresponding quality and concentration, have a pronounced oxygen storage capability which allows a high temperature increase by virtue of the exothermic reaction to be implemented.

In as far as the heating element comprises precious metals such as, for example, palladium and/or rhodium, a direct oxygen storage capability at least in a specific temperature range is also provided by said precious metals.

In one further preferred design embodiment of the particle filter according to the invention the heating element of the first duct is configured from a first material, and the heating element of the second duct is configured from a second material that is dissimilar to the first material. The advantage is the configuration of dissimilarly high temperature increases in the particle filter.

The particle filters of the prior art in principle have a comparatively slow reaction speed in burning off the soot particles. This, for example by virtue of a burn-off of a soot load that is identical in all locations of the particle filter setting-in almost simultaneously in all filter regions, can result in very high temperatures, which under certain circumstances can lead to the particle filter and/or an optionally present coating being damaged, potentially being present in regions of the particle filters that proceeding from a filter inlet lie in the direction of a filter outlet of the particle filter. The temperature in such a case can be the highest close to the filter outlet of the particle filter. It is to be assumed that the burn-off is relatively slow even at, for example, 800° C., and the heat of the burn-off that has been released in the region of the filter inlet accumulates in the downstream regions, thus likewise in the region ahead of the filter outlet, conjointly accumulating with the heat released in the latter region.

This design embodiment is thus provided with the advantage of initiating a temperature increase in the region of the filler inlet which differs from the temperature increase in the region of the filter outlet. It is advantageous for the heating element in the region of the filter inlet to be configured from a first material, for example palladium, which releases heat only at low and medium temperatures present, for example up to approx. 800° C., in the particle filter, and for the heating element in the region of the filter outlet to be configured from a second material, for example having a high proportion of standard storage materials of modern three-way-catalysts, which also releases heat at even higher temperatures present in the particle filter.

In particular highly loaded particle filters, that is to say particle filters which have a large quantity of soot particles, would thus have to be heated proceeding from the filter outlet, for example. If the burn-off, or the regeneration, respectively, were to be initiated at the filter outlet, the heat released there would be truly released and not be placed as a “thermal burden” in the upstream regions. Under certain peripheral conditions, in particular as long as the flow velocities are not excessive, the so-called soot burn-off frontline would run counter to the flow velocity in the direction of the filter inlet and into the regions of the particle filter configured therein. It can therefore be advantageous for the first material to be configured for reacting at a medium temperature range, and for the second material to be configured for reacting above a further temperature range.

A further increase in an efficient regeneration can be initiated with the aid of a further heating element when the latter is disposed in the duct portion passable by a flow.

In one further design embodiment of the invention, the duct portion impassable by a flow has a stopper, wherein the heating element is configured so as to completely or partially replace the stopper. Particle filters according to the prior art have stoppers which only serve the purpose of closing the duct in a sealing manner. Said stoppers are configured so as to be solid and have a relatively large length. For example, stopper lengths of approx. 7 mm are commonplace for particle filters that are used in or provided for, respectively the gasoline engine sector. A proportion in terms of mass of the stoppers in the clogged filter inlet or filter outlet regions, respectively, is approx. 60 to 70%. Therefore, a complete or partial replacement of said stoppers by a heating element produced from a material having a large proportion of a storage component having a high oxidation heat leads to a vehement temperature increase in the event of the operation of the internal combustion engine being converted from the rich operation to the lean operation, for example in conjunction with an overrun cut-off. A particularly efficient particle filter is thus implemented.

Further advantages, features, and details of the invention are derived from the description hereunder of preferred exemplary embodiments and by means of the drawing. The features and features combinations mentioned above in the description, and the features and feature combinations mentioned in the description of the figures and/or shown in the figures alone hereunder are capable of being used not only in the respective combination set forth, but also in other combinations or individually without departing from the scope of the invention. Identical or functionally equivalent elements are assigned identical reference signs.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 in a t-λ diagram shows a profile of the combustion air ratio λ of exhaust gas, and in a corresponding t-T diagram temperatures in a particle filter according to the prior art, and in a particle filter according to the invention temperature profiles at various positions of the particle filter, determined with the aid of a simulated calculation.

FIG. 2 in a x-T diagram shows temperature profiles at various points in time in the particle filter according to the prior art and the particle filter according to the invention.

FIG. 3 in a schematic illustration shows a particle filter according to the invention

FIG. 4 shows an Ellingham diagram of the elements palladium and rhodium and the oxides thereof.

DETAILED DESCRIPTION

An abrupt temperature increase in a particle filter 1 according to the invention is capable of being initiated by way of an exothermic reaction of a material which has a high oxygen storage proportion in the event of an operation of an internal combustion engine (not illustrated in more detail) being converted from a load operation to an overrun operation. An air/fuel mixture supplied to the internal combustion engine herein is modified in terms of the proportions of said air/fuel mixture. The changeover is preferable so as to proceed from a so-called rich operation, which has a combustion air ratio λ of the air/fuel mixture having a value below 1, to a lean operation, which has a combustion air ratio λ of the air/fuel mixture having a value above 1. On account thereof, the exhaust gas of the internal combustion engine which flows through the particle filter 1 has an increased proportion of oxygen which triggers the exothermic reaction. A simultaneous overrun cut-off substantially increases the proportion of oxygen, on account of which a substantial increase in the temperature in the particle filter 1 is likewise achievable.

FIG. 1 in the lower portion in a t-λ diagram shows a profile L1 of a combustion air ratio λ over the time t ahead of a known particle filter. An abrupt change in the combustion air ratio λ from a value of presently approx. 0.95 to a value of significantly above 1 identifies a point in time of the operational changeover of the internal combustion engine from the load operation to the overrun operation by way of a fuel cut-off.

In the upper and the central portion of FIG. 1 temperature profiles T1, T2, and T3, calculated so as to depend on the operational changeover, are illustrated for various positions along a flow axis of the particle filter. The temperature profiles of a particle filter 1 according to the prior art are illustrated in the upper portion, and temperature profiles of a particle filter 1 according to the invention are illustrated in the central portion of FIG. 1. The temperature profile T0 corresponds to a so-called inlet temperature, thus to the gas temperature ahead of OPF.

The particle filter 1 according to the invention, which is schematically configured according to FIG. 3, has duct portions 13 passable by a flow, and duct portions 14 impassable by a flow. The temperature profiles T1 and T3 show a thermal behavior of the particle filter 1 in a plane close to a filter inlet 3, or close to a filter outlet 4, respectively, of the particle filter 1, thus in planes which also intersect duct portions 14 impassable by a flow. The temperature profile T2 shows the thermal behavior of the particle filter 1 close to a central plane of the particle filter 1, said central plane being configured so as to be centric between the planes of the filter inlet 3 and the filter outlet 4.

By virtue of the thermal capacity of the particle filter 1 per se, the temperatures T1, T2, T3 in the particle filter 1 according to the prior art follow the cooling inlet temperature T0 in a delayed manner. The temperatures T1, T2, T3 in the particle filter 1 according to the invention show other profiles. The temperatures T1, T3 of the planes having duct portions 14 impassable by a flow, immediately upon changing from the (slightly) rich to the lean mixture, increase vehemently in an only unnoticeably delayed manner, in this example by approx. 75° C. As soon as an exothermic filling of an oxygen reservoir in the duct portions 14 impassable by a flow has been completed, these temperatures T1, T3 also follow the steadily chilling inlet temperature T0 in a delayed manner.

The calculations were performed without taking into account a soot burn-off. Measurements (not illustrated in more detail) show that the soot burn-off progresses only very slowly with the particle filter 1 being at approx. 700° C. A regeneration of deposited soot is clearly identifiable at approx. 850° C. The particle filter 1 without soot has hardly regenerated for the load case illustrated here. However, the particle filter 1 according to the invention, having the duct portions 14 impassable by a flow, ignites the soot burn-off such that the latter then progresses in a self-accelerating, or self-preserving manner up to the regeneration being largely completed.

FIG. 2 in an x-T diagram shows temperature profiles at various points in time t0, t1, t2, t3, t4 before and after a change over from a (slightly) rich load operation of the internal combustion engine to the overrun operation by way of the fuel cut-off in the direction of the flow axis of the particle filter 1. The temperature profiles t0, t1, t2, t3, t4 in the particle filter 1 according to the prior art are illustrated in the upper portion of FIG. 2, and the temperature profiles t0, t1, t2, t3, t4 in the particle filter 1 according to the invention are illustrated in the lower portion of FIG. 2.

The temperature profile t0 corresponds to a profile before the operational changeover. The temperature profiles t1, t2, t3, t4 are temperature profiles after the operational changeover, wherein the temperature profile t1 20.2 sec., the temperature profile t2 21.2 sec., the temperature profile t3 22.2 sec, and the temperature profile t4 23.2 sec correspond to a temperature profile across the flow axis after the operational changeover.

The particle filter 1 according to the invention for the internal combustion engine (not illustrated in more detail) is configured in a schematic illustration according to FIG. 3. In the operation of the internal combustion engine which is embodied in the form of a direct-injection gasoline engine, exhaust gas that contains soot particles is created by virtue of a combustion of the air/fuel mixture.

The particle filter 1 has a filter body 2 having a filter inlet 3 passable by a flow, and a filter outlet 4 passable by a flow. A multiplicity of ducts 5, 6 passable by a flow are configured in the filter body 2. The ducts 5, 6 are configured so as to extend lying beside one another along a longitudinal axis L, wherein a flow along the longitudinal axis L takes place.

The ducts 5, 6 in an alternating manner have a closed end on the filter inlet 3 and on the filter outlet 4, respectively. The multiplicity of the ducts and the functional mode of the particle filter 1 will furthermore be described by means of a first duct 5 and of a second duct 6.

The first duct 5 has a first end 7 that is configured so as to face the filter inlet 3, and a second end 8 that is configured so as to face the filter outlet 4. The second duct 6 has a third end 9 that is configured so as to face the filter inlet 3, and a fourth end 10 that is configured so as to face the filter outlet 4. The second end 8 and the third end 9 are configured so as to be impassable by a flow. A flow transfer of the exhaust gas from the first duct 5 to the second duct 6 is performed by way of a common duct wall 11 that is configured between the first duct 5 and the second duct 6.

The ducts wall 11 is configured in a porous manner so as to be permeable to a flow, wherein the soot particles of the exhaust gas flowing through the duct wall 11 accumulate on the duct wall 11, or are deposited thereon, respectively. The exhaust gas flows through the particle filter 1 in the direction of the plotted arrows.

The ducts 5, 6 at the ends 8, 9 thereof that are impassable by a flow are closed with the aid of a stopper 12. In other words, this means that the ducts 5, 6 have in each case one duct portion 13 freely passable by a flow, and one duct portion 14 impassable by a flow.

The stopper 12 has an element cross section QE which corresponds to a cross section Q of the duct 5; 6. Since the ducts 5, 6 in the exemplary embodiment illustrated have an identical cross section, the element cross section QE likewise corresponds to a cross section Q of the second duct 6. The ducts 5, 6 in an exemplary embodiment (not illustrated in more detail) have dissimilar cross sections Q. This means that the stopper 12 has an element cross section QE that is configured so as to be adapted to the cross section Q of the respective duct 5, 6.

The element cross section QE of the stopper 12 in the exemplary embodiment illustrated is consistent across a length L of the stopper 12. The element cross section QE could likewise be variable across the length L thereof. For example, the stopper 12 in an exemplary embodiment (not illustrated in more detail) has a truncated-cone shape having an element cross section QE that varies across the length LE, in as far as the duct 5; 6 has a conical shape.

In the operation of the internal combustion engine the soot particles accumulate in the particle filter 1, wherein an effective flow cross section of the particle filter 1 is reduced over time. The reduction in the effective flow cross section leads to an increase of an exhaust gas back pressure of the internal combustion engine, said exhaust gas back pressure potentially leading to an increase in load cycle losses. This in turn, in the case of a constant output, would result in an increase of a fuel consumption of the internal combustion engine, or, in the case of an identical fuel consumption, in a reduction in the output of the internal combustion engine. A regeneration of the particle filter 1 is thus carried out so as to depend on a so-called loading of the particle filter 1.

In order for the particle filter 1 to be regenerated, said particle filter 1 has at least one heating element 15 which is disposed in the duct portion 14 impassable by a flow. The heating element 15 is composed of a functional material which in the case of an excess of air reacts in an exothermic manner, in other words releases heat and thus leads to a temperature increase in the particle filter 1.

The heating element 15 is configured in the form of the stopper 12 and replaces the latter. The heating element 15 could likewise also be configured as part of the stopper 12. Said heating element 15 is configured from a material which is configured so as to trigger an exothermic reaction when storing oxygen. In other words, this means that the heating element 15 by way of the molecular structure thereof releases heat in a self-acting manner in as far as a storage of oxygen is configured. This means that a release of reaction heat is performed.

The material is a solid material which can be present in at least two modifications. Said solid material in the rich operation of the internal combustion engine is at least partially present in a reduced modification, the first modification, and in a lean operation of the internal combustion engine transforms to an oxidized modification, the second modification. This solid material, also referred to as the functional material, is preferably a mixed oxide from cerium and zirconium oxides, optionally with further substances such as, for example, metals and/or earth metals, lanthanum, praseodymium, ytterbium, as well as aluminum oxide.

The “less noble” noble metals palladium and rhodium which also directly have an oxygen storage capability are also suitable. Said “less noble” noble metals do not oxidize at comparatively high temperatures, for example approximately 900° C., and thus do not store, and thus maintain the noble metallic state thereof. It is irrelevant herein whether this is an exhaust gas having a rich composition corresponding to the rich operation, or an exhaust gas having a lean composition corresponding to the lean operation of the internal combustion engine. According to FIG. 4, rhodium would be able to form rhodium oxide up to approx. 880° C. and thus be able to behave in a non-noble manner up to said temperature.

The functional material, according to the composition thereof, can be configured for the exothermic reaction in different temperature ranges. For example, a first material, for example palladium, has a composition having a reduction/oxidation capability in a low and medium temperature range up to approx. 700° C. A second material such as, for example TWC (three-way-catalyst) standard storage materials, has a composition additionally having an exothermic reaction in a high temperature range. In other words, this means that the first material is configured for reacting at low and medium temperatures present in the particle filter 1, and that the second material is configured for reacting above all of the temperatures present in the particle filter 1.

It goes without saying that all of the stoppers 12 can be replaced in each case by one heating element 15, on account of which the regeneration is improved.

A particle filter 1 having a plurality of heating elements 15 which are configured from a single material and/or a material mix is likewise expedient. The positioning of the heating element or heating elements 15, respectively, at the inlet side or the outlet side can also be chosen so as to be dependent on an installation situation of the particle filter 1 close to or remote from the motor.

In one preferred exemplary embodiment (not illustrated in more detail), all of the stoppers 12 of the particle filter 1 are in each case replaced by one heating element 15. A further exemplary embodiment (not illustrated in more detail) of the particle filter 1 according to the invention at the second end 8 has the heating element 15 configured from the first material, and at the third end 9 has the heating element 15 configured from the second material.

A further exemplary embodiment (not illustrated in more detail) of the particle filter according to the invention at second ends and third ends which are more remote from the central longitudinal axis has heating elements from a first material. At the second ends and the third ends which are closer to the central longitudinal axis, said exemplary embodiment has heating elements from a second material, or no heating elements at all.

A further heating element 15 could also be disposed in the duct portion 13 passable by a flow. Said heating element 15 could be configured from a further material that is dissimilar to the first material and the second material. In other words, this means said heating element 15 is composed from a further material having an oxygen storage capability that is dissimilar to that of the first material and to that of the second material.

LIST OF REFERENCE SIGNS

  • 1 Particle filter
  • 2 Filter body
  • 3 Filter inlet
  • 4 Filter outlet
  • 5 First duct
  • 6 Second duct
  • 7 First end
  • 8 Second end
  • 9 Third end
  • 10 Fourth end
  • 11 Duct wall
  • 12 Stopper
  • 13 Duct portion passable by a flow
  • 14 Duct portion impassable by a flow
  • 15 Heating element
  • L Longitudinal axis
  • LE Length
  • L1 Profile
  • Q Duct cross section
  • QE Element cross section
  • T Temperature
  • T0 Inlet temperature
  • T1 First temperature profile
  • T2 Second temperature profile
  • T3 Third temperature profile
  • t Time
  • t0 Temperature profile before operational changeover
  • t1 Temperature profile after operational changeover
  • t2 Temperature profile after operational changeover
  • t3 Temperature profile after operational changeover
  • t4 Temperature profile after operational changeover
  • λ Combustion air ratio

Claims

1. A particle filter for an internal combustion engine, having a filter body (2), wherein the filter body (2) has a filter inlet (3) passable by a flow, and a filter outlet (4) passable by a flow, and wherein the filter body (2) has at least one first duct (5) passable by a flow, having a first end (7) that is configured so as to face the filter inlet (3), and a second end (8) that is configured so as to face the filter outlet (4), and a second duct (6) passable by a flow, having a third end (9) that is configured so as to face the filter inlet (3), and a fourth end (10) that is configured so as to face the filter outlet (4), and wherein the second end (8) and the third end (9) are configured so as to be impassable by a flow, wherein the ducts (5, 6) are capable of being divided into a duct portion (13) passable by a flow, and a duct portion (14) impassable by a flow, and wherein a flow transfer of an exhaust gas flowing through the filter body (2) proceeding from the first duct (5) to the second duct (6) is performed by way of a common duct wall (11) that is configured between the first duct (5) and the second duct (6), and wherein the duct wall (11) is configured so as to be capable of separating soot particles of the exhaust gas, and wherein:

the first duct (5) and/or the second duct (6) for increasing a reaction temperature present in the particle filter (1) for burning off the soot particles have/has a heating element (15), wherein the heating element (15) is disposed in that duct portion (14) of the duct (5; 6) that is impassable by a flow and is configured from a functional material which reacts in an exothermicic manner when storing oxygen.

2. The particle filter of claim 1,

wherein
the heating element (15) for the release of heat is excitable with the aid of a modification of a combustion air ratio (λ) of the exhaust gas.

3. The particle filter of claim 2,

wherein:
the heating element (15) for the release of heat is excitable with the aid of a modification of a combustion air ratio (λ) of the exhaust gas from a combustion air ratio (λ) having a value below 1 to a value above 1.

4. The particle filter of claim 1,

wherein
the heating element (15) has an element cross section (QE) which corresponds to a cross section (Q) of the duct (5, 6).

5. The particle filter of claim 1,

wherein
the heating element (15) is configured at least from cerium and zirconium oxides and/or the mixed oxides thereof.

6. The particle filter of claim 1

wherein
the heating element (15) comprises palladium and/or rhodium.

7. The particle filter of claim 1,

wherein
the heating element (15) of the first duct (5) is configured from a first material, and the heating element (15) of the second duct (6) is configured from a second material that is dissimilar to the first material.

8. The particle filter of claim 7,

wherein
the first material is configured for reacting at low and medium temperatures present in the particle filter (1), and the second material is configured for reacting above all temperatures present in the particle filter (1).

9. The particle filter of claim 1,

wherein
a further heating element (15) is disposed in the duct portion passable by a flow.

10. The particle filter of claim 1,

wherein
the duct portion impassable by a flow has a stopper (12), wherein the heating element (15) is configured so as to completely or partially replace the stopper (12).
Patent History
Publication number: 20190153920
Type: Application
Filed: Jun 7, 2017
Publication Date: May 23, 2019
Applicant: Dr. Ing. h.c. F. Porsche Aktiengesellschaft (Stuttgart)
Inventor: Clemens Brinkmeier (Korntal-Muenchingen)
Application Number: 16/308,583
Classifications
International Classification: F01N 3/035 (20060101); F01N 3/027 (20060101); F01N 3/08 (20060101);