US20110289903A1 - Device and method for regenerating a particulate filter arranged in the exhaust section of an internal combustion engine - Google Patents
Device and method for regenerating a particulate filter arranged in the exhaust section of an internal combustion engine Download PDFInfo
- Publication number
- US20110289903A1 US20110289903A1 US13/145,816 US201013145816A US2011289903A1 US 20110289903 A1 US20110289903 A1 US 20110289903A1 US 201013145816 A US201013145816 A US 201013145816A US 2011289903 A1 US2011289903 A1 US 2011289903A1
- Authority
- US
- United States
- Prior art keywords
- exhaust
- catalytic converter
- particle filter
- gas flow
- oxidation catalytic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
- F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
- F01N3/023—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles
- F01N3/0231—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles using special exhaust apparatus upstream of the filter for producing nitrogen dioxide, e.g. for continuous filter regeneration systems [CRT]
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
- F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
- F01N3/023—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N11/00—Monitoring or diagnostic devices for exhaust-gas treatment apparatus, e.g. for catalytic activity
- F01N11/002—Monitoring or diagnostic devices for exhaust-gas treatment apparatus, e.g. for catalytic activity the diagnostic devices measuring or estimating temperature or pressure in, or downstream of the exhaust apparatus
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
- F01N13/009—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 having two or more separate purifying devices arranged in series
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
- F01N13/011—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 having two or more purifying devices arranged in parallel
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
- F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
- F01N3/023—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles
- F01N3/025—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles using fuel burner or by adding fuel to exhaust
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
- F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
- F01N3/023—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles
- F01N3/027—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles using electric or magnetic heating means
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/0807—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents
- F01N3/0828—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents characterised by the absorbed or adsorbed substances
- F01N3/0842—Nitrogen oxides
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N9/00—Electrical control of exhaust gas treating apparatus
- F01N9/002—Electrical control of exhaust gas treating apparatus of filter regeneration, e.g. detection of clogging
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2240/00—Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being
- F01N2240/14—Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being a fuel burner
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2240/00—Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being
- F01N2240/16—Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being an electric heater, i.e. a resistance heater
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2410/00—By-passing, at least partially, exhaust from inlet to outlet of apparatus, to atmosphere or to other device
- F01N2410/04—By-passing, at least partially, exhaust from inlet to outlet of apparatus, to atmosphere or to other device during regeneration period, e.g. of particle filter
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2560/00—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics
- F01N2560/06—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics the means being a temperature sensor
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2570/00—Exhaust treating apparatus eliminating, absorbing or adsorbing specific elements or compounds
- F01N2570/14—Nitrogen oxides
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2610/00—Adding substances to exhaust gases
- F01N2610/03—Adding substances to exhaust gases the substance being hydrocarbons, e.g. engine fuel
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/24—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by constructional aspects of converting apparatus
- F01N3/30—Arrangements for supply of additional air
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/40—Engine management systems
Abstract
A device and a method for regenerating a particulate filter that is arranged in the exhaust tract of an internal combustion engine. There is disposed at least one NO oxidation catalytic converter upstream of the particulate filter for the oxidation of NO, and in particular to form NO2. At least one heating device is also provided upstream of the particulate filter, by way of which an exhaust-gas flow that is conducted towards the particulate filter can be heated to a defined temperature in accordance with defined regeneration parameters, in particular in accordance with a degree of loading of the particulate filter and/or in accordance with an efficiency of an NO2-based regeneration of the particulate filter by way of an NO2 quantity formed in the at least one NO oxidation catalytic converter.
Description
- The invention relates to a device for regenerating a particle filter arranged in the exhaust tract of an internal combustion engine, as per the preamble of claim 1, and to a method for regenerating a particle filter arranged in the exhaust tract of an internal combustion engine, as per the preamble of claim 8.
- The invention relates in particular to a method and a device for regenerating particle filters in the case of internal combustion engines operated with an excess of air, such as diesel engines or gasoline engines with direct injection, such as are used for example in motor vehicles or utility vehicles.
- To minimize carbon-containing fine matter particles, so-called particle separators or particle filters are conventionally used in vehicles. A typical particle separator arrangement in vehicles is known for example from EP 10 727 65 A2. Such particle separators differ from particle filters in that the exhaust-gas flow is conducted along the separating structures, whereas in the case of particle filters, the exhaust gas must flow through the filter medium. As a result of said difference, particle filters tend to become blocked, which increases exhaust-gas back pressure, that is to say causes an undesired pressure increase at the exhaust-gas outlet of an internal combustion engine, which in turn reduces engine power and results in increased fuel consumption of the internal combustion engine. An example of such a particle filter arrangement is known from EP 03 418 32 A2.
- In both of the arrangements described above, in each case, an oxidation catalytic converter arranged upstream of the particle separator or of the particle filter oxidizes the nitrogen monoxide (NO) in the exhaust gas, by means of the residual oxygen (O2) likewise contained therein, to form nitrogen dioxide (NO2), specifically according to the following equation:
-
2NO+O2<−>2NO2 (1) - Here, it must be observed that the equilibrium of the above reaction at high temperatures lies on the side of NO. This in turn has the result that the attainable NO2 fractions at high temperatures are limited on account of said thermodynamic limitation.
- The NO2 is in turn converted in the particle filter with the hydrocarbon-containing superfine particles to form CO, CO2, N2 and NO. A continuous removal of the accumulated fine matter particles therefore takes place by means of the powerful oxidizing agent NO2, such that regeneration cycles, such as must be carried out in cumbersome fashion in other arrangements, may be dispensed with. In this connection, passive regeneration is referred to, as per the following equations:
-
C+2NO2->2NO+CO2 (2) -
NO2+C->NO+CO (3) - Here, the formation of carbon monoxide as per
equation 3 plays only a secondary role; in general, a complete oxidation of the carbon up to the oxidation state +4, in the form of carbon dioxide, takes place, wherein for said oxidation, two NO2 molecules are required per carbon molecule. - Aside from NO2, on the platinum-containing NO oxidation catalytic converters, SO3 is also formed from sulfur contained in the fuel and/or engine oil. The SO3 and NO2 condense at cold points in the exhaust tract to form highly corrosive sulfuric and nitric acid, such that the exhaust system leading up to the particle filters must be formed from high-grade steel in order to prevent corrosion.
- If complete oxidation of the carbon accumulated in the particle filter is not possible by means of NO2, then the hydrocarbon fraction and therefore the exhaust-gas counterpressure increase continuously. To prevent this, at present, particle filters are increasingly provided with a catalytic coating for the oxidation of NO (EP 03 418 32 A2). These are specifically platinum-containing catalysts. The disadvantage of said method is however that the NO2 formed on the particle filter can serve only for the oxidation of particles which have been deposited downstream of the catalytically active coating for NO oxidation, that is to say therefore within the filter medium. In contrast, if a layer of deposited particles, a so-called filter cake, forms on the filter surface and therefore on the catalytically active coating, the particle-filter-side NO oxidation catalytic converter thus lies downstream of the filter cake, such that the soot particles deposited there cannot be oxidized by means of NO2 from the NO oxidation catalyst applied to the particle filter. Furthermore, strictly speaking, only the catalyst coating applied on the untreated gas side contributes to the performance of the system, because the NO2 catalytically formed on the clean gas side can no longer come into contact with the soot deposited on the untreated gas side and within the filter material.
- A further problem of the coating of the particle filter consists in that the geometric surface areas of the filter are considerably smaller than those of conventionally used catalytic converter substrates. The reason for this is that the filters require relatively large free cross sections and therefore free volume on the untreated gas side in order to store soot and engine oil ashes. If use is made of ceramic filter substrates, this is realized by means of a low cell density of 50 cpsi to 200 cpsi. In contrast, pure catalytic converters are conventionally formed with cell densities of 400 cpsi to 900 cpsi. The increase from 50 cpsi to 900 cpsi yields an increase in the geometric surface area from 1 m2/l to 4 m2/l, as a result of which considerable increases in conversion on the catalytic converters are possible.
- For these reasons, despite the catalytic coating of the filter, it is not possible to dispense with an NO oxidation catalytic converter upstream of the particle filter, resulting in a relatively large structural volume. This is the case even if the NO oxidation catalytic converters and the particle filters form a structural unit in which the inlet region of the particle filter is formed as an NO oxidation catalytic converter, as described for example in DE 103 270 30 A1.
- In all of said variants for passive regeneration by means of NO2, it must be observed that, below 200° C. to 230° C., the soot oxidation cannot be further increased by means of an increase in NO2 quantities. The conversion maximum is reached at approximately 370° C. Above said temperature, the soot oxidation takes place according to the above-described reaction (2), that is to say two NO2 molecules react with one carbon molecule. This means, in mass terms, that 0.13 g of carbon can be oxidized with one gram of NO2, that is to say the soot oxidation can be increased arbitrarily by increasing the NO2 quantity. This relationship is illustrated in
FIG. 1 . - If the temperatures lie below 200° C.-230° C., therefore, reliable functioning of the particle filter cannot be ensured. This usually arises in lightly-loaded engines installed in vehicles, for example in passenger motor vehicles, urban buses or refuse collection vehicles, which additionally spend long periods at idle. Therefore, specifically in such situations, a second option for particle filter regeneration is applied in which the exhaust-gas temperature is actively raised. This takes place for example by means of the metered addition of hydrocarbons (HC) upstream of catalytic converters, in particular HC oxidation catalytic converters. A considerable temperature increase is attained on account of the exothermic nature of the oxidation of the added hydrocarbons by means of the catalytic converters.
-
“HC”+O2->CO+H2O (4) -
“HC”+O2->CO2+H2O (5) - To adequately thermally stabilize said catalytic converters, these usually contain palladium as an active component. Palladium has no NO oxidation activity and furthermore reduces the NO oxidation activity of any platinum contained in the catalytic converters. As a result, HC oxidation catalytic converters have considerably lower NO oxidation activity than pure NO oxidation catalytic converters.
- If a temperature increase to over 600° C. is possible as a result of the dosing of hydrocarbons, the carbon deposited in the particle filter is oxidized or burned off by means of oxygen, as per the following equations:
-
C+O2->CO2 (6) -
2C+O2→2CO (7) - However, with said so-called active filter regeneration, there is the risk that the exothermic burn-off of the carbon-containing soot can lead to an intense temperature increase to over 1000° C. and therefore to damage to the particle filter and/or to downstream catalytic converters. Furthermore, since the temperature increase must be maintained for several minutes in order to ensure a quantitative oxidation of the soot particles, the demand for hydrocarbons is not inconsiderable, and impairs the efficiency of the internal combustion engine, because the fuel is conventionally used as the hydrocarbon source.
- A further problem in contrast to passive regeneration is the high carbon monoxide emissions during the regeneration, the formation of which carbon monoxide is described in
equation 7. For this reason, a further catalytic converter for the oxidation of the carbon monoxide formed during the regeneration must be attached to the particle filter and/or downstream of the particle filter in order to prevent the discharge of said carbon monoxide to the environment. - A simple combination of passive and active regeneration by the metered addition of hydrocarbons upstream of NO oxidation catalytic converters is not expedient:
- As a result of the temperature increase to over 600° C., virtually no more NO2 is formed on the NO oxidation catalytic converters on account of the thermodynamic limitation. Furthermore, the oxidation of NO is hindered on account of the large quantities of hydrocarbons, resulting in a severe reduction in NO2 formation. As a result, the particles must be oxidized by means of oxygen alone, because no NO2 is available in said phase, which lengthens the regeneration time and leads to high carbon monoxide emissions.
- At the same time, NO oxidation catalytic converters are significantly less stable with regard to thermal damage than catalytic converters for hydrocarbon oxidation, because irreversible sintering of the active components, and therefore a decrease in NO oxidation activity, occurs at temperatures of over 550° C.
- It is therefore an object of the present invention to provide a device and a method for regenerating a particle filter arranged in the exhaust tract of an internal combustion engine, by means of which device and method functionally reliable and safe particle filter regeneration can be attained in a structurally simple and compact manner.
- Said object is achieved, with regard to the device, by means of the features of claim 1. With regard to the method, said object is achieved by means of the features of claim 8. Advantageous refinements of these are specified in each case in the subclaims referred back to said claims 1 and 8.
- According to the invention, upstream of the particle filter, in addition to the at least one NO oxidation catalytic converter there is also provided at least one heating device by means of which an exhaust-gas flow conducted to the particle filter can be heated as a function of defined regeneration parameters, in particular can be heated to a defined temperature as a function of a degree of loading of the particle filter and/or a regeneration efficiency or regeneration work of an NO2 regeneration of the particle filter by means of an NO2 quantity formed on the at least one NO oxidation catalytic converter. By means of the heated exhaust-gas flow, therefore, the temperature at the particle filter can be increased, wherein at the same time high quantities of NO2 are still available from the NO oxidation catalytic converter because, in the region of the NO oxidation catalytic converter, no temperature increase takes place which has an adverse effect on NO2 formation, and no increased hydrocarbon concentrations are present which lead to a decrease in NO oxidation activity. Said temperature increase of the exhaust-gas flow upstream of the particle filter therefore takes place in a part of the exhaust tract which lies downstream of the NO oxidation catalytic converter and/or parallel to the NO oxidation catalytic converter and upstream of the particle filter. According to the invention, therefore, a functionally reliable combination of active and passive regeneration of a particle filter is provided which utilizes the respective advantages and avoids negative interactions.
- With such a solution according to the invention, it is therefore possible for the particle filter regeneration to be realized exclusively by means of the NO2 quantity, wherein if required, the temperature at the particle filter is shifted into the optimum temperature window for the respectively desired reaction by means of an electronic monitoring unit designed as a control and/or regulating device. That is to say, by means of the at least one heating device, the exhaust-gas flow conducted to the particle filter is merely heated, at predefined times and/or in predefined operating states of the internal combustion engine and/or of the aftertreatment system, to a temperature which lies below the regeneration temperature of a pure active particle filter regeneration by means of the metered addition of hydrocarbons to the exhaust-gas flow. Here, said exhaust-gas flow conducted to the particle filter is preferably heated to a temperature of less than 600° C., preferably of less than or equal to approximately 550° C., most preferably of less than or equal to approximately 450° C. Here, the temperatures particularly preferably lie in a temperature window from 300° C. to 550° C., most preferably in a temperature window from 350° C. to 450° C. In the solution according to the invention, therefore, the temperature of the exhaust-gas flow conducted to the particle filter is particularly preferably predefined, as a function of an NO2 concentration and/or of the loading state of the particle filter with carbon-containing particles, in a defined region of at least one exhaust-gas flow, specifically with the aid of a control and/or regulating device as an electronic monitoring device.
- On account of the relatively high temperatures that are possible according to the invention with simultaneous assistance of the soot oxidation by the powerful oxidizing agent NO2, it is possible for the regeneration duration to be shortened and for the regeneration temperature to be lowered to approximately 400° C. In this way, the hydrocarbon quantity required for the temperature increase and the carbon monoxide emissions occurring as a result of the regeneration are likewise reduced, as is the risk of an uncontrollable temperature increase and associated thermal damage to the particle filter or downstream catalytic converters.
- To ensure reliable regeneration of the particle filter or particle separator, it is provided according to one particularly preferred embodiment that, at least during a defined regeneration mode, the mass ratio between carbon and nitrogen dioxide contained in the exhaust gas is at least 1:4, preferably at least 1:8. Said regeneration mode is characterized in particular by a defined increase in the exhaust-gas temperature upstream of the particle filter.
- Here, in a first physical embodiment, the heating device is preferably arranged in parallel, in terms of flow, with the NO oxidation catalytic converter. For example, the heating device and NO oxidation catalytic converter are hereby decoupled in terms of flow such that the heating device and the NO oxidation catalytic converter are traversed by in each case one exhaust gas or gas flow. In physical terms, this means that for example a first exhaust-gas flow flows through the NO oxidation catalytic converter and a second exhaust-gas flow flows through or over the heating device, the two exhaust-gas flows being merged downstream of the NO oxidation catalytic converter and the heating device and upstream of the particle filter. In a first device variant, it is possible for this purpose for a branch line from a supply line leading to the NO oxidation catalytic converter to be branched off upstream of the NO oxidation catalytic converter, the branch line then opening into a discharge line, which leads from the NO oxidation catalytic converter to the particle filter, downstream of the NO oxidation catalytic converter. The heating device should then be arranged in the region of the branch line. Alternatively, however, a structural design is also possible in which the NO oxidation catalytic converter encloses or surrounds the heating device at least in regions. In this way, in particular, cooling of the heating device is advantageously prevented.
- For the flow branching of an exhaust-gas flow, in a further particularly preferred refinement of the solution according to the invention, a shut-off device, for example a flap or the like, is provided which is coupled by means of a control and/or regulating device and by means of which the quantity of the gas flow conducted via the NO oxidation catalytic converter and/or of the gas flow conducted via the heating device can be controlled or regulated as a function of defined operating or shut-off parameters.
- As an alternative to the parallel arrangement, in terms of flow, of at least one NO oxidation catalytic converter and at least one heating device, it may also be provided that these are arranged in series with one another in terms of flow and are traversed by one exhaust-gas flow. For this purpose, the heating device should then be arranged downstream of the NO oxidation catalytic converter and upstream of the particle filter.
- The heating device itself is preferably formed by a heating catalytic converter which in turn is preferably designed as an oxidation catalytic converter. It is also particularly preferable for a dosing device to be provided by means of which a reducing agent for an exothermic reaction is dosed to the exhaust-gas flow upstream of the heating catalytic converter at predefined times and in predefined quantities as a function of defined dosing parameters. Here, the dosing takes place in particular periodically. For the particularly preferred situation that the heating catalytic converter is an HC oxidation catalytic converter, the reducing agent preferably takes the form of hydrocarbons.
- Here, the hydrocarbons preferably take the form of fuel. It is particularly preferable for the added hydrocarbons to be dosed by means of a separate dosing device, for example an injection nozzle or the like, which is provided in the exhaust tract. Said dosing then takes place upstream of the heating catalytic converter by virtue of a predefined quantity of hydrocarbons being dosed or injected into the exhaust-gas flow at predefined times. Particularly preferable here, as already mentioned above, is a dosing which takes place, by means of an electronic control unit, corresponding to predefined control and/or regulating parameters, and which is for example periodically repeated.
- For the oxidation of the dosed hydrocarbons, therefore, the exhaust-gas flow to be heated can be conducted over the heating device, which is designed preferably as an HC oxidation catalytic converter, as a result of which the exhaust-gas flow is heated. The heating power to be obtained in this way is however limited by the available oxygen quantity. This is because, if the lambda value, that is to say the ratio of oxygen quantity to fuel quantity, reaches the value 1, oxidation of the hydrocarbons is no longer possible. To avoid this, in a further preferred refinement, it is proposed that fresh air be supplied to the exhaust-gas flow to be heated after a certain predefined temperature and/or a predefined time is reached and/or when a predefined lambda or oxygen value is undershot. Said optional fresh-air supply causes an increase in the lambda value and therefore also an increase in the maximum possible heating power. Here, the fresh air may generally be branched off on the charge-air side of the internal combustion engine, specifically for example also upstream and/or downstream of an opening of an exhaust-gas recirculation line into a charge-air line of the internal combustion engine. The use of a blower or compressor for the delivery of fresh air is also conceivable.
- An alternative possibility for increasing the exhaust-gas temperature consists in using a burner, which is operated preferably with fuel, as a heating device. The above-described problems with regard to excessively low air ratios apply to a particularly great extent to said burner, which problems can be worked around analogously to the solution for the heating catalytic converter.
- The heating device, in particular the heating catalytic converter, may basically be arranged outside the exhaust tract, that is to say such that the exhaust gas does not flow around said heating catalytic converter. This however leads to relatively rapid cooling of said heating device, in particular of the heating catalytic converter. It is therefore more expedient for the heating device, in particular the heating catalytic converter, to be arranged in the exhaust tract such that the exhaust gas flows at least partially around said heating catalytic converter, as a result of which the heat losses to the environment are reduced.
- In particular, it is possible for the HC oxidation catalytic converter, for example, as a heating catalytic converter to be surrounded by the NO oxidation catalytic converter. It is also possible for a common substrate to be used for the NO oxidation catalytic converter and for the HC oxidation catalytic converter, for example, to be used as a heating catalytic converter, which common substrate has different catalytic coatings in different regions. By means of flow-manipulating fixtures, such as guide plates and/or partitions, upstream of the substrate, it is ensured that no hydrocarbons impinge on the regions with NO oxidation coating during the regeneration phase.
- It is also conceivable for the heating device, in particular the heating catalytic converter, and the NO oxidation catalytic converter to be accommodated in a common housing.
- To further improve the system, it is also possible for the heating catalytic converter, designed preferably as an HC oxidation catalytic converter, to additionally be provided with NO oxidation activity, as a result of which the NO2 fractions are increased in non-regeneration operation and thereby the oxidation of the particles by means of the passive regeneration is improved. In this way, it is possible for the intervals between the active increases in temperature to be lengthened. Here, the heating catalytic converter should be designed to be thermally more stable than the pure NO oxidation catalytic converter. Said heating catalytic converter conventionally has lower NO oxidation activity than pure NO oxidation catalytic converters, as has already been mentioned above.
- To avoid high hydrocarbon concentrations downstream of the particle filter in particular when HC oxidation catalytic converters are used as heating catalytic converters, this may be provided with a catalyst for the oxidation of hydrocarbons. It is also conceivable for a catalyst with hydrocarbon oxidation activity to be applied or arranged upstream and/or downstream of the particle filter. As active components, consideration is given inter alia to vanadium oxide, cerium, zeolites and elements of the platinum metal group.
- In contrast, as active components both for the NO oxidation catalytic converters and also for the HC oxidation catalytic converters, consideration is given primarily to metals of the platinum metal group, but the composition thereof differs: to improve the thermal stability of the HC oxidation catalytic converters, the palladium fraction thereof, for example, is higher than that of the NO oxidation catalytic converters. For the HC oxidation catalytic converters, cerium is basically also taken into consideration as an active element.
- The activity of the two catalytic converter types may be additionally increased for example through the use of zeolites.
- The regeneration may also optionally be improved by increasing the NO2 availability. This may be achieved by increasing the NOx untreated emissions. This may be done by varying engine operating parameters such as injection pressure, exhaust-gas recirculation rates, start of injection, number of injections, intake throttle position etc. As a result of the higher NOx availability, the NO2 quantity formed on the NO oxidation catalytic converters is simultaneously increased. A further option is for the NO2 quantity formed to be increased by improving the NO oxidation on the NO oxidation catalytic converters. This is conventionally possible by increasing the residence time, in particular by reducing the exhaust-gas quantity conducted over the catalytic converters, and/or by increasing the temperature of the NO oxidation catalytic converters. To achieve this, it is possible inter alia to use the measures already described above for increasing the NOx untreated emissions.
- To reduce not only the particles but also the emissions of nitrogen oxides, it is possible for catalytic converters for NOx reduction, such as for example at least one NOx storage catalytic converter and/or at least one SCR catalytic converter, to additionally be provided in the exhaust tract or exhaust section. The NOx storage catalytic converters may be arranged downstream of the oxidation catalytic converters and/or downstream of the particle filter, whereas the SCR catalytic converters may also conceivably be positioned upstream of the oxidation catalytic converters. For the NOx storage catalytic converters, platinum and/or barium and/or calcium are preferably used as active components. In contrast, for the SCR catalytic converters, the use of tungsten-oxide-stabilized vanadium pentoxide, preferably based on titanium dioxide, or iron zeolites or copper zeolites or cobalt zeolites or zirconium oxide is expedient.
- The installation space of such a system for the reduction of nitrogen oxides and particles can be reduced by virtue of the at least one particle filter and the at least one SCR catalytic converter and/or the at least one NOx trap catalytic converter forming a structural unit, wherein the particle filter may be provided with an SCR catalyst and/or NOx storage catalyst coating.
- In summary, it can therefore be stated that, by means of the solution according to the invention, in which active and passive particle filter regeneration are combined at least at times, a range of advantages can be attained: The regeneration capability of the system can thus be actively influenced. Furthermore, the adjustment can be carried out such that the greatest amount of regeneration work takes place by means of the oxidation of soot by means of NO2 which is formed on an upstream NO oxidation catalytic converter, that is to say the reducing agent or fuel is added in metered fashion only if the regeneration work by means of NO2 is not sufficient, such that fuel consumption is considerably minimized in relation to pure active particle filter regeneration. Furthermore, the solution according to the invention is associated with considerably lower thermal loading of the particle filter, in particular of the diesel particle filter, and of any downstream exhaust-gas aftertreatment components. A further significant advantage is that the regeneration can take place very uniformly, as a result of which the risk of so-called soot clusters and burn-through of the particle filter is reduced. A further significant advantage can be considered to be that the platinum requirement and therefore the costs for producing the exhaust-gas aftertreatment system are considerably lower than those of pure HCl regeneration systems (HydroCarbon Injection), that is to say of pure active regeneration systems, since smaller quantities of hydrocarbons must be oxidized, and an oxidation of carbon monoxide formed during the active regeneration is not required. Furthermore, on account of the small driving temperature difference, the heat losses to the environment are lower than in the case of the pure active particle filter regeneration, as a result of which less expenditure is required for insulation and material etc.
- A plurality of exemplary embodiments of the present invention will be explained below on the basis of a drawing, in which:
-
FIG. 1 schematically shows a diagram which shows by way of example the improvement in soot oxidation as a result of the increase in temperature; -
FIG. 2 schematically shows a diagram illustrating the improvement in soot oxidation as a result of an increase in NO2 availability and temperature; -
FIG. 3 shows a first embodiment of a parallel arrangement of an NO oxidation catalytic converter and of a heating catalytic converter, designed as an HC oxidation catalytic converter, upstream of a particle filter; -
FIG. 4 schematically shows an alternative embodiment of a parallel arrangement of an NO oxidation catalytic converter and of a heating catalytic converter, designed as an HC oxidation catalytic converter, upstream of a particle filter; -
FIG. 5 schematically shows a further alternative refinement of a device according to the invention for regenerating a particle filter arranged in the exhaust tract of an internal combustion engine, with a serial arrangement of an NO oxidation catalytic converter and an HC oxidation catalytic converter upstream of a particle filter; and -
FIG. 6 schematically shows an alternative embodiment to -
FIG. 5 , in which a burner is used instead of a heating catalytic converter. -
FIG. 3 shows a first exemplary embodiment according to the invention, in which, in the exhaust tract 1 of an internal combustion engine not illustrated here, in particular of a diesel internal combustion engine, an exhaust-gas flow 2 is conducted by means of asupply line 3 to an NO oxidationcatalytic converter 4. Adischarge line 5 leads from said NO oxidationcatalytic converter 4 to aparticle filter 6. - Upstream of the NO oxidation
catalytic converter 4, abranch line 7 branches off from thesupply line 3 and opens into thedischarge line 5 downstream of the NO oxidationcatalytic converter 4. - An HC oxidation catalytic converter 8 as a heating device is arranged in said
branch line 7. Furthermore, anozzle 9 is arranged in thebranch line 7 upstream of the HC oxidation catalytic converter 8, by means of whichnozzle 9fuel 10 as reducing agent can be injected into thebranch line 7 upstream of the HC oxidation catalytic converter 8. - For this reason, the
nozzle 9 is a constituent part of adosing device 11 which, aside from thenozzle 9, also has afuel tank 12 and a control and/or regulatingdevice 13 which controls and/or regulates the dosing. - A shut-off
element 14 is optionally arranged in thebranch line 7 upstream of thenozzle 9, which shut-offelement 14 may likewise be coupled to an electronic monitoring unit, which is however not illustrated here, in order to branch off a defined exhaust-gas quantity from the exhaust-gas flow 2 at predefined times, such that a first exhaust-gas flow 2′ flows through the NO oxidationcatalytic converter 4 and a second exhaust-gas flow 2″ flows through thebranch line 7. Said two exhaust-gas flows are then merged again downstream of the NO oxidationcatalytic converter 4 and downstream of the HC oxidation catalytic converter 8, and supplied as exhaust-gas flow 2″″ to theparticle filter 6. - As is illustrated merely schematically in
FIG. 3 , the NO oxidationcatalytic converter 4 is designed and dimensioned to be significantly larger than the HC oxidation catalytic converter 8, the reason for this being that the particle filter regeneration should be carried out substantially as NO2-based particle filter regeneration, that is to say by means of the NO2 formed in the NO oxidationcatalytic converter 4. Only in the event that the regeneration work of the NO2 formed in or on the NO oxidationcatalytic converter 4 is not sufficient isfuel 10 dosed into thebranch line 7 via thenozzle 9 in a manner correspondingly controlled or regulated by means of the control and/or regulatingdevice 13. At the same time, by means of corresponding activation of the shut-offelement 14, a corresponding exhaust-gas mass flow as a second exhaust-gas flow 2″ is conducted via thebranch line 7 in order to supply an exhaust-gas flow enriched with hydrocarbons to the HC oxidation catalytic converter 8, as a result of which an exothermic reaction takes place in the HC oxidation catalytic converter, which exothermic reaction generates a hot second exhaust-gas flow 2″ which is mixed with the first exhaust-gas flow 2′ downstream of the NO oxidationcatalytic converter 4, such that said first exhaust-gas flow 2′, which as before is enriched with NO2, is raised to a higher temperature level, as a result of which the NO2-based soot oxidation in theparticle filter 6 takes place in an optimized manner, as schematically illustrated inFIG. 1 . In said figure, 15 denotes the ideal line which represents 100% conversion; specifically, here, 0.13 g of carbon is oxidized per gram of NO2 supplied. If it is now detected by the electronic monitoring unit that the NO2 regeneration work in thelower temperature range 16 no longer provides satisfactory regeneration results and/or the degree of loading of the particle filter has risen above a predefined limit, then by means of the measures specified above, the temperature level is raised to theupper temperature range 17 in order to make more effective, and optimize, the soot burn-off. Here, on account of the combination according to the invention of possible active and passive regeneration, it is for example sufficient for the exhaust-gas flow conducted to theparticle filter 6 to be raised to a temperature level which lies preferably in the range from 370° C. to 400° C. As a result of the additional increase in the NO2 level shown inFIG. 2 by means of the increase, already described above, of the NOx untreated emissions and/or the improvement in the NO oxidation activity of the NO oxidation catalytic converter by means of changed operating parameters of the internal combustion engine and/or of the NO oxidation catalytic converters, the regeneration capability can be additionally improved in relation to the pure increase in exhaust-gas temperature. - The determination of the NO2 quantity and/or of the regeneration capability and/or of the degree of loading of the particle filter may be carried out for example by means of mathematical models and/or characteristic maps and/or by means of exhaust-gas sensors, in particular pressure sensors, NO2 sensors, NOx sensors, temperature sensors and/or sensors for determining the particle or soot quantity.
- That which has been stated above applies analogously to the alternative refinement according to
FIG. 4 , in which, in contrast to the refinement according toFIG. 3 , the NO oxidationcatalytic converter 4 and HC oxidation catalytic converter 8 have been connected in parallel in such a way that the HC oxidation catalytic converter 8, which forms the heating catalytic converter or the heating device, is surrounded here at least in regions by the NO oxidation catalytic converter. In this way, the cooling of the HC oxidation catalytic converter 8 is more effectively prevented than is the case with a separate arrangement of an HC oxidation catalytic converter 8. Here, similarly to the embodiment according toFIG. 3 , thefuel 10 is dosed only to the HC oxidation catalytic converter 8. For the division of the exhaust-gas flows through the NO oxidationcatalytic converter 4 on the one hand and through the HC oxidation catalytic converter 8 on the other hand, it is possible here, too, for flow guiding elements to be provided, for example aguide element 18 illustrated merely schematically inFIG. 3 . Furthermore, a shut-off element may also be provided in the region of saidguide element 18, which shut-off element controls and/or regulates the quantity or generally the inflow of an exhaust-gas flow to the HC oxidation catalytic converter 8, as has already been described above in conjunction with the shut-offelement 14 and thebranch line 7. - Through the use of a guide element, it is also made possible for the NO oxidation
catalytic converter 4 and the HC oxidation catalytic converter 8 to be applied to a common catalytic converter substrate. Here, those regions which, during the regeneration, are impinged on by hydrocarbons from the supply unit, designed in this case for example as anozzle 9, are formed, in particular coated, as an HC oxidation catalytic converter 8, whereas the remaining regions are formed, in particular coated, as NO oxidationcatalytic converters 4. The different regions usually vary over the cross section, that is to say perpendicular to the flow direction. -
FIG. 4 also shows merely schematically a NOx reductioncatalytic converter 21 which is likewise arranged in the exhaust tract 1 and which is designed for example as a NOx storage catalytic converter or SCR catalytic converter. - The mode of operation and method implementation otherwise correspond to those already described in conjunction with
FIGS. 1 to 3 . - Finally,
FIG. 5 shows an embodiment in which the NO oxidationcatalytic converter 4 and the HC oxidation catalytic converter 8 are not connected in parallel but rather are arranged in series. In physical terms, this means that the HC oxidation catalytic converter 8 is arranged downstream of the NO oxidationcatalytic converter 4 and also upstream of theparticle filter 6. The dosing of thefuel 10 as reducing agent then takes place here likewise such that said fuel cannot pass into the NO oxidationcatalytic converter 4, by virtue of the dosing taking place downstream of the NO oxidationcatalytic converter 4 and upstream of the HC oxidation catalytic converter 8. The method implementation and the mode of operation otherwise correspond to those already explained in more detail above in conjunction withFIGS. 1 to 4 . The significant difference here therefore consists in that, in contrast to the refinements ofFIGS. 3 and 4 , the exhaust-gas flow 2 is not branched or divided, but rather the entire exhaust-gas flow 2 flows firstly through the NO oxidationcatalytic converter 4, subsequently through the HC oxidation catalytic converter 8 and subsequently further through theparticle filter 6. -
FIG. 6 finally shows an alternative embodiment to that shown inFIG. 5 , in which, instead of an HC oxidation catalytic converter 8 as a heating device, use is made of aburner 19 operated with fuel. The use of such a burner is always possible in particular also in connection with the embodiments mentioned above, in particular in connection with the embodiment according toFIG. 3 . The design ofFIG. 6 otherwise corresponds to that ofFIG. 5 , such that in order to avoid repetitions, reference is made to the statements made above. - In all the embodiments, therefore, the exhaust-gas flow or a partial exhaust-gas flow is conducted over a heating device. The heating power to be attained in this way is however limited, as already described above, by the available oxygen quantity. To avoid this, it is optionally possible for fresh air, for example a fresh-air flow branched off at the charge-air side, to be supplied to the exhaust-gas flow to be heated after a predefined temperature and/or a predefined time is reached and/or when a predefined lambda or oxygen value is undershot. The
fresh air supply 20 is illustrated merely highly schematically by an arrow inFIGS. 3 , 5 and 6.
Claims (32)
1-15. (canceled)
16. A configuration for regenerating a particle filter arranged in an exhaust tract of an internal combustion engine, comprising:
at least one NO oxidation catalytic converter for oxidizing NO arranged upstream of the particle filter in an exhaust-gas flow direction;
at least one heating device arranged upstream of the particle filter and configured to heat an exhaust-gas flow being conducted to the particle filter to a defined temperature in dependence of one or more defined regeneration parameters.
17. The configuration according to claim 16 , wherein said NO oxidation catalytic converter is configured for oxidizing NO to form NO2.
18. The configuration according to claim 16 , wherein the one or more defined regeneration parameters are selected from the group consisting of a degree of loading of the particle filter and an efficiency of an NO2-based regeneration of the particle filter by way of an NO2 quantity formed on said at least one NO oxidation catalytic converter.
19. The configuration according to claim 16 , wherein, at least during a regeneration phase characterized by a defined increase in the exhaust-gas temperature upstream of the particle filter, a mass ratio between carbon and nitrogen dioxide contained in the exhaust gas is at least 1:4.
20. The configuration according to claim 19 , wherein, during the regeneration phase, the mass ratio of carbon to nitrogen dioxide in the exhaust gas is at least 1:8.
21. The configuration according to claim 16 , wherein said at least one heating device is configured for heating the exhaust-gas flow conducted to the particle filter to a temperature lying below a regeneration temperature of a pure active particle filter regeneration by way of a metering of hydrocarbons into the exhaust-gas flow.
22. The configuration according to claim 21 , wherein said at least one heating device is configured for heating the exhaust-gas flow to a temperature of less than 600° C.
23. The configuration according to claim 21 , wherein said at least one heating device is configured for heating the exhaust-gas flow to a temperature of less than or equal to approximately 550° C. and within a temperature window of approximately 300° C. to 550° C.
24. The configuration according to claim 21 , wherein said at least one heating device is configured for heating the exhaust-gas flow to a temperature of less than or equal to approximately 450° C. and within a temperature window of approximately 350° C. to 450° C.
25. The configuration according to claim 16 , wherein said at least one heating device is connected in parallel, with regard to the exhaust-gas flow, with said NO oxidation catalytic converter, so as to subject each of said heating device and said NO oxidation catalytic converter to one exhaust gas or gas flow, with a first exhaust-gas flow flowing through said NO oxidation catalytic converter and a second exhaust-gas flow flowing through or over said heating device, and the first and second exhaust-gas flows are merged downstream of said NO oxidation catalytic converter and said heating device and upstream of the particle filter.
26. The configuration according to claim 16 , wherein said at least one heating device is connected in series, with regard to the exhaust-gas flow, downstream of said NO oxidation catalytic converter and upstream of the particle filter.
27. The configuration according to claim 16 , wherein said at least one heating device is a burner or an oxidation catalytic converter formed as a heating catalytic converter.
28. The configuration according to claim 16 , wherein said at least one heating device is an HC oxidation catalytic converter, and wherein a dosing device is disposed for metering hydrocarbons for an exothermic reaction into the exhaust-gas flow upstream of said heating catalytic converter at predefined times and in predefined quantities as a function of defined dosing parameters.
29. The configuration according to claim 28 , wherein said at least one heating device is an HC oxidation catalytic converter with NO oxidation activity and said dosing device is configured for periodically dosing in hydrocarbons for an exothermic reaction into the exhaust-gas flow upstream of said heating catalytic converter.
30. The configuration according to claim 16 , which comprises a fresh-air line and a shut-off element for selectively shutting off said fresh-air line, said fresh-air line enabling a charge-air-side fresh-air flow and/or a charge air flow branched off downstream of an opening point of an exhaust-gas recirculation line into a charge-air line or a fresh-air flow delivered by way of a blower or compressor to be supplied to an exhaust-gas flow upstream of said at least one heating device and/or upstream of said NO oxidation catalytic converter.
31. A method for regenerating a particle filter arranged in an exhaust tract, which method comprises:
conducting an exhaust-gas flow through at least one NO oxidation catalytic converter for the oxidation of NO upstream of the particle filter;
conducting an exhaust-gas flow through at least one heating device and to the particle filter, and heating the exhaust-gas flow to a defined temperature in dependence on defined regeneration parameters.
32. The method according to claim 31 , which comprises providing the configuration according to claim 16 and carrying out the method with the configuration.
33. The method according to claim 31 , which comprises heating the exhaust gas for active and passive particle filter regeneration which are combined at least at times.
34. The method according to claim 31 , wherein the defined regeneration parameters are selected from a degree of loading of the particle filter and/or an efficiency of an NO2-based regeneration of the particle filter by means of an NO2 quantity formed on the at least one NO oxidation catalytic converter.
35. The method according to claim 31 , wherein at least during a regeneration phase, which is characterized by a defined increase in an exhaust-gas temperature upstream of the particle filter, a mass ratio between carbon and nitrogen dioxide contained in the exhaust gas is at least 1:4.
36. The method according to claim 35 , wherein the mass ratio of carbon to nitrogen dioxide is 1:8, at least during the regeneration phase.
37. The method according to claim 31 , which comprises heating the exhaust-gas flow conducted to the particle filter with the at least one heating device to a temperature below a regeneration temperature of a pure active particle filter regeneration by way of metering hydrocarbons into the exhaust-gas flow.
38. The method according to claim 37 , which comprises heating the exhaust-gas flow to a temperature below 600° C.
39. The method according to claim 37 , which comprises heating the exhaust-gas flow to a temperature of less or equal to approximately 550° C., with a temperature window extending from approximately 300° C. to no more than 550° C.
40. The method according to claim 37 , which comprises heating the exhaust-gas flow to a temperature of less or equal to approximately 450° C., with a temperature window extending from approximately 350° C. to no more than 450° C.
41. The method according to claim 31 , which comprises providing an open-loop or closed-loop control device for predefining the temperature of the exhaust-gas flow conducted to the particle filter in a defined region of at least one exhaust-gas flow as a function of an NO2 concentration and/or the loading of the particle filter and/or the regeneration capability of the particle filter.
42. The method according to claim 31 , which comprises providing the heating device in parallel, in terms of flow, with the NO oxidation catalytic converter and conducting a first exhaust-gas flow through the NO oxidation catalytic converter and a second exhaust-gas flow through or over the heating device, and merging the first and second exhaust-gas flows downstream of the NO oxidation catalytic converter and the heating device and upstream of the particle filter.
43. The method according to claim 31 , wherein the heating device is arranged downstream of the NO oxidation catalytic converter and upstream of the particle filter, and passing the exhaust-gas flow in a series flow therethrough.
44. The method according to claim 31 , which comprises supplying a predefined quantity of a charge-air-side fresh-air flow and/or a predefined quantity of a charge-air flow branched off downstream of the opening point of an exhaust-gas recirculation line into a charge-air line to the exhaust-gas flow upstream of the heating device at predefined times and/or when a predefined exhaust-gas temperature is exceeded and/or when a predefined lambda value is undershot and/or when a predefined oxygen value is undershot.
45. The method according to claim 31 , which comprises, during a regeneration of the particle filter, varying at least one of an NOx untreated emissions of the internal combustion engine or an oxidation capability of the NO oxidation catalytic converter by adjusting defined operating parameters.
46. The method according to claim 45 , wherein the varying step comprises increasing at least one operating parameter selected from the group consisting of a fuel injection pressure, a start of injection, an exhaust-gas recirculation rate, and a number of injections.
Applications Claiming Priority (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE102009005733.1 | 2009-01-22 | ||
DE102009005733A DE102009005733A1 (en) | 2009-01-22 | 2009-01-22 | Device for regenerating particle filter in exhaust manifold of e.g. diesel engine of passenger vehicle, has nitrogen monoxide- and hydrocarbon-oxidation catalyst provided upstream of particle filter |
EP09015450 | 2009-12-14 | ||
EP09015450 | 2009-12-14 | ||
PCT/EP2010/000084 WO2010083944A1 (en) | 2009-01-22 | 2010-01-11 | Device and method for regenerating a particulate filter arranged in the exhaust section of an internal combustion engine |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/EP2010/000084 A-371-Of-International WO2010083944A1 (en) | 2009-01-22 | 2010-01-11 | Device and method for regenerating a particulate filter arranged in the exhaust section of an internal combustion engine |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US14/738,173 Continuation US10240498B2 (en) | 2009-01-22 | 2015-06-12 | Device and method for regenerating a particulate filter arranged in the exhaust section of an internal combustion engine |
Publications (1)
Publication Number | Publication Date |
---|---|
US20110289903A1 true US20110289903A1 (en) | 2011-12-01 |
Family
ID=41820573
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/145,816 Abandoned US20110289903A1 (en) | 2009-01-22 | 2010-01-11 | Device and method for regenerating a particulate filter arranged in the exhaust section of an internal combustion engine |
US14/738,173 Active 2030-02-08 US10240498B2 (en) | 2009-01-22 | 2015-06-12 | Device and method for regenerating a particulate filter arranged in the exhaust section of an internal combustion engine |
Family Applications After (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US14/738,173 Active 2030-02-08 US10240498B2 (en) | 2009-01-22 | 2015-06-12 | Device and method for regenerating a particulate filter arranged in the exhaust section of an internal combustion engine |
Country Status (6)
Country | Link |
---|---|
US (2) | US20110289903A1 (en) |
EP (1) | EP2379851B1 (en) |
CN (1) | CN102301101B (en) |
BR (1) | BRPI1004925B1 (en) |
RU (1) | RU2482295C2 (en) |
WO (1) | WO2010083944A1 (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20160053648A1 (en) * | 2013-04-03 | 2016-02-25 | Renault Trucks | Method and internal combustion engine arrangement for regenerating an exhaust after-treatment device |
US20160053654A1 (en) * | 2013-02-22 | 2016-02-25 | Isuzu Motors Limited | Exhaust purification device for internal combustion engine |
US20180080359A1 (en) * | 2016-09-20 | 2018-03-22 | Umicore Ag & Co. Kg | Scr diesel particle filter with oxidation catalyst and oxygen storage catalyst loadings, and exhaust system including the same |
US10920701B2 (en) | 2016-06-03 | 2021-02-16 | Isuzu Motors Limited | Filter regeneration system for internal combustion engine and filter regeneration method for internal combustion engine |
US11952931B2 (en) | 2019-03-27 | 2024-04-09 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Exhaust emission control device, internal combustion engine equipped therewith and method for exhaust emission control |
Families Citing this family (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20130291518A1 (en) * | 2012-05-07 | 2013-11-07 | Ajay Patel | Exhaust system having a pre-heater |
CN104153857B (en) * | 2013-05-15 | 2018-01-30 | 罗伯特·博世有限公司 | Can initiative regeneration exhaust gas aftertreatment system and its initiative regeneration method |
DE102013016701B4 (en) * | 2013-10-08 | 2017-06-14 | Khd Humboldt Wedag Gmbh | Process for the denitrification of bypass exhaust gases in a plant for the production of cement clinker and plant for the production of cement clinker |
DE102014005153B4 (en) * | 2014-04-08 | 2023-12-14 | Andreas Döring | Exhaust gas aftertreatment system and method for exhaust gas aftertreatment |
US9909473B2 (en) * | 2014-11-13 | 2018-03-06 | Ford Global Technologies, Llc | Method and system for gas particulate filter |
US9650930B2 (en) * | 2015-01-12 | 2017-05-16 | Ford Global Technologies, Llc | Emission control device regeneration |
RU174571U1 (en) * | 2017-03-23 | 2017-10-20 | Общество С Ограниченной Ответственностью "Научно-Производственная Компания "Промышленные Экологические Технологии" | DEVICE FOR CLEANING EXHAUST GASES OF INTERNAL COMBUSTION ENGINE |
DE102017124032A1 (en) * | 2017-10-16 | 2019-04-18 | Eberspächer Exhaust Technology GmbH & Co. KG | Gas / reagent mixing assembly |
KR102394626B1 (en) * | 2017-11-30 | 2022-05-09 | 현대자동차주식회사 | Method for predicting of nitrogen dioxide emission in diesel engine |
DE102018221575A1 (en) * | 2018-12-12 | 2020-06-18 | Eos Gmbh Electro Optical Systems | Method and device for the aftertreatment of particles carried in a process gas and filter therefor |
DE102019204298A1 (en) * | 2019-03-27 | 2020-10-01 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Exhaust gas purification device, internal combustion engine equipped therewith and method for exhaust gas purification |
CN110848001B (en) * | 2019-10-15 | 2021-05-25 | 江苏大学 | System for cyclically regenerating DPF by using NTP and control method |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5233830A (en) * | 1990-05-28 | 1993-08-10 | Toyota Jidosha Kabushiki Kaisha | Exhaust gas purification system for an internal combustion engine |
US20080092530A1 (en) * | 2004-10-15 | 2008-04-24 | Toyota Jidosha Kabushiki Kasiha | Exhaust Purification System For Internal Combustion Engine |
US20080295499A1 (en) * | 2007-05-31 | 2008-12-04 | James Joshua Driscoll | Exhaust system utilizing a low-temperature oxidation catalyst |
US20090031711A1 (en) * | 2004-07-24 | 2009-02-05 | Tillman Braun | Exhaust gas system, especially for an internal combustion engine of a motor vehicle |
US20120167555A1 (en) * | 2009-08-13 | 2012-07-05 | Cummins Ip, Inc. | Apparatus, system, and method for adaptive engine system control with integrated global position sensing |
Family Cites Families (18)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4485621A (en) * | 1983-01-07 | 1984-12-04 | Cummins Engine Company, Inc. | System and method for reducing particulate emissions from internal combustion engines |
US4902487A (en) | 1988-05-13 | 1990-02-20 | Johnson Matthey, Inc. | Treatment of diesel exhaust gases |
DE19934932B4 (en) | 1999-07-26 | 2011-06-30 | MAN Truck & Bus AG, 80995 | Method and device for separating fine particles from the exhaust gas of internal combustion engines |
US6276139B1 (en) * | 2000-03-16 | 2001-08-21 | Ford Global Technologies, Inc. | Automotive engine with controlled exhaust temperature and oxygen concentration |
DE10062377B4 (en) * | 2000-12-14 | 2005-10-20 | Siemens Ag | Apparatus and method for heating an exhaust catalyst for a supercharged internal combustion engine |
JP3758617B2 (en) * | 2002-07-12 | 2006-03-22 | トヨタ自動車株式会社 | Exhaust gas purification device for internal combustion engine |
JP4107017B2 (en) * | 2002-09-02 | 2008-06-25 | 三菱ふそうトラック・バス株式会社 | Engine control device |
JP2004324587A (en) * | 2003-04-25 | 2004-11-18 | Mitsubishi Fuso Truck & Bus Corp | Emission control device of internal combustion engine |
DE10327030A1 (en) | 2003-06-16 | 2005-01-13 | Oberland Mangold Gmbh | Collecting unit for an exhaust gas purification device |
JP2005090450A (en) | 2003-09-19 | 2005-04-07 | Hino Motors Ltd | Exhaust emission control device |
KR100590959B1 (en) * | 2003-12-30 | 2006-06-19 | 현대자동차주식회사 | DOC/DPF system for diesel engine |
US7862640B2 (en) * | 2006-03-21 | 2011-01-04 | Donaldson Company, Inc. | Low temperature diesel particulate matter reduction system |
DE102006028436A1 (en) * | 2006-06-21 | 2007-12-27 | Robert Bosch Gmbh | Method for operating an exhaust gas cleaning system arranged in an exhaust area of an internal combustion engine |
JP2011511897A (en) * | 2008-02-07 | 2011-04-14 | マック トラックス インコーポレイテッド | Method and apparatus for regenerating a catalytic diesel particulate filter (DPF) by active NO2 utilization regeneration with enhanced effective NO2 supply |
US8359840B2 (en) * | 2009-09-29 | 2013-01-29 | Ford Global Technologies, Llc | Method for adjusting boost pressure while regenerating a particulate filter for a direct injection engine |
US8528323B2 (en) * | 2010-06-30 | 2013-09-10 | GM Global Technology Operations LLC | System and method for particulate matter filter regeneration using a catalytic converter as a combustor |
US20120073270A1 (en) * | 2010-09-27 | 2012-03-29 | Cox Glenn B | Exhaust system and retrofitting method |
DE102010044102A1 (en) * | 2010-11-18 | 2012-05-24 | Ford Global Technologies, Llc | Exhaust system for internal combustion engines with particle filter |
-
2010
- 2010-01-11 WO PCT/EP2010/000084 patent/WO2010083944A1/en active Application Filing
- 2010-01-11 EP EP10700486.3A patent/EP2379851B1/en active Active
- 2010-01-11 BR BRPI1004925-8A patent/BRPI1004925B1/en active IP Right Grant
- 2010-01-11 US US13/145,816 patent/US20110289903A1/en not_active Abandoned
- 2010-01-11 RU RU2011134878/06A patent/RU2482295C2/en active
- 2010-01-11 CN CN201080005424.7A patent/CN102301101B/en active Active
-
2015
- 2015-06-12 US US14/738,173 patent/US10240498B2/en active Active
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5233830A (en) * | 1990-05-28 | 1993-08-10 | Toyota Jidosha Kabushiki Kaisha | Exhaust gas purification system for an internal combustion engine |
US20090031711A1 (en) * | 2004-07-24 | 2009-02-05 | Tillman Braun | Exhaust gas system, especially for an internal combustion engine of a motor vehicle |
US20080092530A1 (en) * | 2004-10-15 | 2008-04-24 | Toyota Jidosha Kabushiki Kasiha | Exhaust Purification System For Internal Combustion Engine |
US20080295499A1 (en) * | 2007-05-31 | 2008-12-04 | James Joshua Driscoll | Exhaust system utilizing a low-temperature oxidation catalyst |
US20120167555A1 (en) * | 2009-08-13 | 2012-07-05 | Cummins Ip, Inc. | Apparatus, system, and method for adaptive engine system control with integrated global position sensing |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20160053654A1 (en) * | 2013-02-22 | 2016-02-25 | Isuzu Motors Limited | Exhaust purification device for internal combustion engine |
US9664090B2 (en) * | 2013-02-22 | 2017-05-30 | Isuzu Motors Limited | Exhaust purification device for internal combustion engine |
US20160053648A1 (en) * | 2013-04-03 | 2016-02-25 | Renault Trucks | Method and internal combustion engine arrangement for regenerating an exhaust after-treatment device |
US9850795B2 (en) * | 2013-04-03 | 2017-12-26 | Volvo Truck Corporation | Method and internal combustion engine arrangement for regenerating an exhaust after-treatment device |
US10920701B2 (en) | 2016-06-03 | 2021-02-16 | Isuzu Motors Limited | Filter regeneration system for internal combustion engine and filter regeneration method for internal combustion engine |
US20180080359A1 (en) * | 2016-09-20 | 2018-03-22 | Umicore Ag & Co. Kg | Scr diesel particle filter with oxidation catalyst and oxygen storage catalyst loadings, and exhaust system including the same |
US10914214B2 (en) * | 2016-09-20 | 2021-02-09 | Umicore Ag & Co. Kg | SCR diesel particle filter with oxidation catalyst and oxygen storage catalyst loadings, and exhaust system including the same |
US11952931B2 (en) | 2019-03-27 | 2024-04-09 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Exhaust emission control device, internal combustion engine equipped therewith and method for exhaust emission control |
Also Published As
Publication number | Publication date |
---|---|
BRPI1004925B1 (en) | 2020-06-16 |
US20150275722A1 (en) | 2015-10-01 |
EP2379851A1 (en) | 2011-10-26 |
EP2379851B1 (en) | 2015-12-16 |
CN102301101B (en) | 2014-07-16 |
WO2010083944A1 (en) | 2010-07-29 |
US10240498B2 (en) | 2019-03-26 |
RU2482295C2 (en) | 2013-05-20 |
RU2011134878A (en) | 2013-02-27 |
BRPI1004925A2 (en) | 2016-08-23 |
CN102301101A (en) | 2011-12-28 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US10240498B2 (en) | Device and method for regenerating a particulate filter arranged in the exhaust section of an internal combustion engine | |
US10316739B2 (en) | Method and device for the purification of diesel exhaust gases | |
US8756927B2 (en) | Method and device for the regeneration of a particle filter arranged in the exhaust gas tract of an internal combustion engine | |
EP2342433B1 (en) | Method and apparatus for cold starting an internal combustion engine | |
US8991161B2 (en) | DeNOx of diesel engine exhaust gases using a temperature-controlled precatalyst for providing NO2 in accordance with the requirements | |
EP1451453B1 (en) | System and methods for improved emission control of internal combustion engines | |
EP1620635B1 (en) | System and methods for improved emission control of internal combustion engines using pulsed fuel flow | |
US7210288B2 (en) | Exhaust gas aftertreatment installation and method | |
US7788906B2 (en) | Methods and systems for controlling internal combustion engines | |
US9157356B2 (en) | Method for operating a motor vehicle diesel engine | |
US20070289291A1 (en) | Apparatus and Method for NOx Reduction | |
RU2652264C2 (en) | Method and device for increasing exhaust gas temperature in exhaust system of a turbocharged internal combustion engine | |
EP1857648B1 (en) | System and methods for improving emission control of internal combustion engines |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: MAN TRUCK & BUS AG, GERMANY Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:DOERING, ANDREAS;REEL/FRAME:027395/0496 Effective date: 20110808 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |