DE102005005664A1 - Operating an internal combustion engine comprises e.g. adjusting the interval between and duration of rich phase operation in response to the age state of a storage catalyst - Google Patents
Operating an internal combustion engine comprises e.g. adjusting the interval between and duration of rich phase operation in response to the age state of a storage catalyst Download PDFInfo
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- DE102005005664A1 DE102005005664A1 DE102005005664A DE102005005664A DE102005005664A1 DE 102005005664 A1 DE102005005664 A1 DE 102005005664A1 DE 102005005664 A DE102005005664 A DE 102005005664A DE 102005005664 A DE102005005664 A DE 102005005664A DE 102005005664 A1 DE102005005664 A1 DE 102005005664A1
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- 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
- F01N3/0814—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents combined with catalytic converters, e.g. NOx absorption/storage reduction catalysts
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- 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
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- 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
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- 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
- F01N3/0821—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents combined with particulate filters
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- 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
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- 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
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/021—Introducing corrections for particular conditions exterior to the engine
- F02D41/0235—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus
- F02D41/027—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to purge or regenerate the exhaust gas treating apparatus
- F02D41/0275—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to purge or regenerate the exhaust gas treating apparatus the exhaust gas treating apparatus being a NOx trap or adsorbent
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/14—Introducing closed-loop corrections
- F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
- F02D41/1473—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the regulation method
- F02D41/1475—Regulating the air fuel ratio at a value other than stoichiometry
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/14—Introducing closed-loop corrections
- F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
- F02D41/1477—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the regulation circuit or part of it,(e.g. comparator, PI regulator, output)
- F02D41/1479—Using a comparator with variable reference
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/14—Introducing closed-loop corrections
- F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
- F02D41/1486—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor with correction for particular operating conditions
- F02D41/1487—Correcting the instantaneous control value
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- 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
- F01N2240/25—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 ammonia generator
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- 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
- F01N2430/00—Influencing exhaust purification, e.g. starting of catalytic reaction, filter regeneration, or the like, by controlling engine operating characteristics
- F01N2430/06—Influencing exhaust purification, e.g. starting of catalytic reaction, filter regeneration, or the like, by controlling engine operating characteristics by varying fuel-air ratio, e.g. by enriching fuel-air mixture
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B37/00—Engines characterised by provision of pumps driven at least for part of the time by exhaust
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D2200/00—Input parameters for engine control
- F02D2200/02—Input parameters for engine control the parameters being related to the engine
- F02D2200/08—Exhaust gas treatment apparatus parameters
- F02D2200/0802—Temperature of the exhaust gas treatment apparatus
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- 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
Description
Die vorliegende Erfindung betrifft ein Verfahren zum Betrieb einer Brennkraftmaschine mit Abgasreinigungsanlage, insbesondere eines Dieselmotors mit einem Speicherkatalysator (NSK) und einem SCR-Katalysator.The The present invention relates to a method of operating an internal combustion engine with emission control system, in particular a diesel engine with a Storage catalytic converter (NSK) and an SCR catalytic converter.
Die Abgasnachbehandlung bei Dieselmotoren erfolgt derzeit durch Katalysatoren, die im sauerstoffreichen Abgas die gasförmigen Emissionen (HC, CO, NOx) umsetzen. Für eine effektive NOx-Entfernung kann zusätzlich ein Reduktionsmittel (zum Beispiel HC, H2, CO oder NH3) zudosiert werden (so genanntes SCR-Verfahren). Hierbei zeigt Ammoniak (NH3) die höchste Selektivität bezüglich der Umwandlung von NOx zu Stickstoff; Ammoniak kann dabei beispielsweise entweder als Reinstoff oder als NH3-abspaltende Vorstufe im Fahrzeug mitgeführt oder in einer Katalysatoreinheit im Fahrzeug selbst erzeugt werden.Exhaust gas aftertreatment in diesel engines is currently carried out by catalysts which convert the gaseous emissions (HC, CO, NO x ) in the oxygen-rich exhaust gas. For effective NO x removal, a reducing agent (for example HC, H 2 , CO or NH 3 ) can additionally be added (so-called SCR method). Here, ammonia (NH 3 ) shows the highest selectivity for the conversion of NO x to nitrogen; For example, ammonia can either be carried in the vehicle as a pure substance or as a precursor which releases NH 3 or can be produced in a catalyst unit in the vehicle itself.
Ein weiterer Weg zur Entstickung stellt die Einspeicherung der Stickoxide in so genannte Speicherkatalysatoren (NSK) dar. Die Regeneration dieser Katalysatoren erfolgt durch zyklischen unterstöchiometrischen Betrieb (innermotorisch und/oder durch Nacheinspritzung realisierbar), wobei die eingespeicherten Stickoxide wieder freigesetzt und zu Stickstoff reduziert werden. Ein Nachteil dieses Systems ist jedoch die erhöhte HC/CO-Emission während der Regenerationsphasen und die Schwefelempfindlichkeit der basischen Speicherkomponenten. Der NSK hat das Problem, dass er im Betrieb bedingt durch hohe Temperaturen und Verunreinigungen (insbes. Schwefel) an Wirksamkeit verliert (Alterung des Katalysators). Die Entschwefelung kann zum Beispiel durch verlängerte Regenerationsphasen bei höheren Temperaturen erfolgen. Insgesamt hat man bei einem NSK-System, bedingt durch die Regenerationsphasen, einen Zielkonflikt zwischen einer maximalen NOx-Umsetzung und einer minimalen HC/CO-Emissionen.Another way to denitrify is the storage of nitrogen oxides in so-called storage catalysts (NSK). The regeneration of these catalysts is carried out by cyclic substoichiometric operation (internal engine and / or by post-injection feasible), the stored nitrogen oxides are released again and reduced to nitrogen. However, a disadvantage of this system is the increased HC / CO emission during the regeneration phases and the sulfur sensitivity of the basic storage components. The NSK has the problem that it loses its effectiveness in operation due to high temperatures and impurities (especially sulfur) (aging of the catalyst). The desulfurization can be done, for example, by prolonged regeneration phases at higher temperatures. Overall, in a NSK system, due to the regeneration phases, there is a trade-off between a maximum NO x conversion and a minimum HC / CO emissions.
Die
Man hat jedoch ferner festgestellt, dass bei einer günstigen Parameterwahl in einem NSK während des unterstöchiometrischen Betriebs zur Regeneration neben dem Stickstoff auch Ammoniak gebildet werden kann, der, wie oben erwähnt, als Reaktionsmittel bei der Reduktion Stickoxid zu Stickstoff wirkt. Deshalb ist bei modernen Abgasreinigungsanlagen dem NSK ein SCR-Katalysator nachgeschaltet, um die Stickoxid-Umsetzung zu erhöhen. Dieser nachgeschaltete SCR-Katalysator kann den in der Regenerationsphase im NSK entstandenen Ammoniak einspeichern und ihn dann im anschließenden Magerbetrieb zur selektiven Reduktion der Stickoxide in Stickstoff einsetzen.you has also found that with a favorable choice of parameters in a NSK during of the stoichiometric Plant for regeneration next to the nitrogen also formed ammonia can be, as mentioned above, acts as a reaction agent in the reduction of nitrogen oxide to nitrogen. That is why the NSK is an SCR catalytic converter in modern emission control systems downstream to increase the nitrogen oxide conversion. This downstream SCR catalyst can be found in the regeneration phase in the NSK Store ammonia and then use it in the subsequent lean operation for selective Use reduction of nitrogen oxides in nitrogen.
Als Magerbetrieb wird im Allgemeinen ein überstöchiometrischer Motorbetrieb bezeichnet, bei dem in der Verbrennung ein Sauerstoffüberschuss (λ > 1) herrscht. Unter dem für die Regenerationsphasen eingesetzten Fettbetrieb wird ein unter stöchiometrischer Motorbetrieb verstanden, bei dem in der Verbrennung ein Kraftstoffüberschuss (λ < 1) vorhanden ist.When Lean operation generally becomes superstoichiometric engine operation denotes, in which in combustion an excess of oxygen (λ> 1) prevails. Under for The regeneration phases used fat operation is a stoichiometric Engine operation understood in which in the combustion of a fuel surplus (λ <1) is present.
Eine
Brennkraftmaschine mit einer Abgasreinigungsanlage, die einen NSK
und einen nachgeschalteten SCR-Katalysator enthält, ist zum Beispiel in den
Dokumenten
Bei
der
Die
Inzwischen wird in vielen Märkten eine Wirkungsüberwachung der emissionsmindernden Maßnahmen (OBD) gefordert, die die Einhaltung der jeweils geltenden Emissionsgrenzen überwachen soll. Zu den Überwachungsmitteln gehören zum Beispiel die Lambdasonde, eine Stickoxid-Sensorik und an verschiedenen Stellen in der Abgasreinigungsanlage vorgesehene Temperatursensoren.meanwhile will be in many markets an impact monitoring the emission reduction measures (OBD) that monitor compliance with applicable emission limits should. To the monitoring means belong for example, the lambda probe, a nitric oxide sensor and at various Provide provided in the emission control system temperature sensors.
Der vorliegenden Erfindung liegt die Aufgabe zugrunde, ein Verfahren zum Betrieb einer Brennkraftmaschine mit Abgasreinigungsanlage, bestehend aus einem NSK und einem nachgeschalteten SCR-Katalysator, zu schaffen, das die Stickoxid-Umsetzung weiter optimiert.Of the The present invention is based on the object, a method for operating an internal combustion engine with exhaust gas purification system, consisting of a NSK and a downstream SCR catalyst, to create that the nitric oxide conversion further optimized.
Diese Aufgabe wird durch ein Verfahren zum Betrieb einer Brennkraftmaschine mit Abgasreinigungsanlage mit den Merkmalen des Anspruchs 1 oder des Anspruchs 2 gelöst. Vorteilhafte Ausgestaltungen und Weiterbildungen der Erfindung sind Gegenstand der Unteransprüche.These The object is achieved by a method for operating an internal combustion engine with emission control system with the features of claim 1 or of claim 2 solved. Advantageous embodiments and further developments of the invention are Subject of the dependent claims.
Bei dem Verfahren zum Betrieb einer Brennkraftmaschine mit Abgasreinigungsanlage, wobei die Abgasreinigungsanlage einen Stickoxidadsorptions- und Ammoniakerzeugungskatalysator (NSK) und einen stromab des Stickoxidadsorptions- und Ammoniakerzeugungskatalysators angeordneten Stickoxidreduktionskatalysator (SCR-Katalysator) aufweist, wird wechselweise ein Fettbetrieb der Brennkraftmaschine mit fetter Abgaszusammensetzung und ein Magerbetrieb der Brennkraftmaschine mit magerer Abgaszusammensetzung durchgeführt. Zur Optimierung der Stickoxid-Umsetzung der Abgasreinigungsanlage werden die folgenden Prozesse einzeln oder in Kombination durchgeführt:
- a) es wird ein Alterungszustandes des Stickoxidadsorptions- und Ammoniakerzeugungskatalysators ermittelt, und die Intervalle und Zeitdauern der Fettbetriebe der Brennkraftmaschine werden dann in Abhängigkeit von dem ermittelten Alterungszustand des Stickoxidadsorptions- und Ammoniakerzeugungskatalysators eingestellt, sodass auch bei einem älteren System eine optimale Ammoniakausbeute im NSK und damit eine optimale Stickoxidumsetzung im SCR-Katalysator erzielt werden kann;
- b) es wird eine Temperatur des Stickoxidadsorptions- und Ammoniakerzeugungskatalysators ermittelt und dann wird, falls die ermittelte Temperatur des Stickoxidadsorptions- und Ammoniakerzeugungskatalysators eine untere Ammoniakerzeugungs-Grenztemperatur übersteigt, der Lambdawert während des Fettbetriebs der Brennkraftmaschine niedriger als ein oberer Ammoniakerzeugungs-Lambdagrenzwert eingestellt, sodass bei einem Temperaturbereich des NSK, in dem Ammoniak erzeugt werden kann, eine optimale Ausbeute an Ammoniak erreicht wird;
- c) der Lambdaverlauf während des Fettbetriebs der Brennkraftmaschine wird zur Optimierung der Ammoniakbildung in dem Stickoxidadsorptions- und Ammoniakerzeugungskatalysators zeitlich variabel gesteuert; und
- d) es wird eine Temperatur des Stickoxidreduktionskatalysators ermittelt und dann wird, falls die ermittelte Temperatur des Stickoxidreduktionskatalysators eine obere Ammoniakeinspeicher-Grenztemperatur übersteigt, der Lambdawert während des Fettbetriebs der Brennkraftmaschine höher als ein oberer Ammoniakerzeugungs-Lambdagrenzwert erhöht, sodass möglichst kein Ammoniak mehr im NSK gebildet wird, wenn dieser bei zu hohen Temperaturen am SCR-Katalysator nicht mehr eingespeichert werden kann.
- a) an aging state of the nitrogen oxide adsorption and ammonia generation catalyst is determined, and the intervals and durations of the engine fat operations are then set depending on the determined aging state of the nitrogen oxide adsorption and ammonia generation catalyst, so that even in an older system optimal ammonia yield in the NSK and thus optimal nitrogen oxide conversion in the SCR catalyst can be achieved;
- b) a temperature of the nitrogen oxide adsorption and ammonia generation catalyst is determined, and then if the detected temperature of the nitrogen oxide adsorption and ammonia generation catalyst exceeds a lower ammonia generation limit temperature, the lambda value is set lower than an upper ammonia generation lambda limit during the rich operation of the internal combustion engine a temperature range of the NSK in which ammonia can be generated, an optimum yield of ammonia is achieved;
- c) the Lambda curve during the rich operation of the internal combustion engine is controlled variable in time to optimize the ammonia formation in the nitrogen oxide adsorption and ammonia generation catalyst; and
- d) a temperature of the nitrogen oxide reduction catalyst is determined and then, if the determined temperature of the nitrogen oxide reduction catalyst exceeds an upper ammonia storage limit temperature, the lambda value during the rich operation of the internal combustion engine higher than an upper ammonia generation lambda limit increases, so that no more ammonia if possible formed in the NSK if it can no longer be stored at too high temperatures on the SCR catalytic converter.
Falls die Abgasreinigungsanlage der Brennkraftmaschine zusätzlich mit einem Rußfilter dem Stickoxidadsorptions- und Ammoniakerzeugungskatalysator und dem Stickoxidreduktionskatalysator versehen ist, kann zur Optimierung der Stickoxid-Umsetzung der Abgasreinigungsanlage auch der folgende Prozess einzeln oder in Kombination mit einem oder mehreren der obigen Prozesse durchgeführt werden:
- e) eine Temperatur des Rußfilters wird höher als eine obere Ammoniakadsorptions-Grenztemperatur eingestellt, sodass das im NSK erzeugte Ammoniak nicht vom Rußfilter adsorbiert wird, sondern möglichst vollständig in den SCR-Katalysator gelangen kann. Durch diese Maßnahme wird zudem vermieden, dass im Rußfilter adsorbierter Ammoniak bei oxidierenden Bedingungen zu Stickoxid oxidiert wird und es dadurch eine Erhöhung der Stickoxid-Emission resultiert.
- e) a temperature of the soot filter is set higher than an upper ammonia adsorption limit temperature, so that the ammonia produced in the NSK is not adsorbed by the soot filter, but can get as completely as possible in the SCR catalyst. By this measure, it is also avoided that in the soot filter adsorbed ammonia is oxidized under oxidizing conditions to nitric oxide and thereby results in an increase in nitrogen oxide emission.
Den oben angegebenen Prozessen a) bis e), die einzeln oder in Kombination durchgeführt werden können, ist gemeinsam, dass zur Optimierung der Stickoxid-Umsetzung im nachgeschalteten SCR-Katalysator diesem möglichst viel Ammoniak zur Reduktion der Stickoxide in Stickstoff Verfügung gestellt wird.The above-mentioned processes a) to e), individually or in combination carried out can be is common that to optimize the nitrogen oxide reaction in the downstream SCR catalyst this possible much ammonia is provided for the reduction of nitrogen oxides in nitrogen.
Bezüglich des Prozesses a) werden im Fall eines höheren ermittelten Alterungszustandes des Stickoxidadsorptions- und Ammoniakerzeugungskatalysators die Intervalle und/oder die Zeitdauern der Fettbetriebe der Brennkraftmaschine verkürzt, wobei bevorzugt die Intervalle der Fettbetriebe der Brennkraftmaschine bis auf unter 150 Sekunden verkürzt werden und die Zeitdauern der Fettbetriebe der Brennkraftmaschine bis auf unter 3 Sekunden verkürzt werden. Außerdem kann bei Prozess a) im Fall eines höheren ermittelten Alterungszustandes des Stickoxidadsorptions- und Ammoniakerzeugungskatalysators der Lambdawert während der Fettbetriebe der Brennkraftmaschine verringert werden.Regarding the Process a) become in the case of a higher determined aging condition the nitrogen oxide adsorption and ammonia generation catalyst the Intervals and / or the periods of fat operations of the internal combustion engine shortened, wherein preferably the intervals of the fat operations of the internal combustion engine be shortened to less than 150 seconds and the periods of the fat operations of the internal combustion engine up to shorter than 3 seconds become. Furthermore can process a) in case of a higher determined aging condition the nitrogen oxide adsorption and ammonia generation catalyst of Lambda value during the fat operations of the internal combustion engine can be reduced.
Der Alterungszustandes des Stickoxidadsorptions- und Ammoniakerzeugungskatalysators kann beispielsweise auf der Basis eines Lambdaverzugs während des Fettsprungs, eines Messsignals eines Stickoxidsensors oder von Alterungsmodellen ermittelt werden.Of the Aging state of the nitrogen oxide adsorption and ammonia generating catalyst can for example, based on a lambda delay during the Fat jump, a measurement signal of a nitrogen oxide sensor or determined by aging models become.
Bezüglich des Prozesses b) beträgt die untere Ammoniakerzeugungs-Grenztemperatur des Stickoxidadsorptions- und Ammoniakerzeugungskatalysators vorzugsweise etwa 250°C und der obere Ammoniakerzeugungs-Lambdagrenzwert beträgt vorzugsweise etwa 0,95.Regarding the Process b) is the lower ammonia generation limit temperature of the nitrogen oxide adsorption and ammonia generating catalyst preferably about 250 ° C and the The upper ammonia generation lambda limit is preferably about 0.95.
Bezüglich des Prozesses c) wird der Lambdawert während des Fettbetriebs der Brennkraftmaschine vorzugsweise stufenweise oder kontinuierlich erhöht.Regarding the Process c) the lambda value during rich operation of the Internal combustion engine preferably increased gradually or continuously.
Bezüglich des Prozesses d) beträgt die obere Ammoniakeinspeicher-Grenztemperatur bevorzugt etwa 400°C und der obere Ammoniakerzeugungs-Lambdagrenzwert beträgt bevorzugt etwa 0,95.With respect to process d), the upper limit of ammonia storage limit temperature is preferably about 400 ° C and the upper ammonia level The supply lambda limit is preferably about 0.95.
Bezüglich des Prozesses e) beträgt die obere Ammoniakadsorptions-Grenztemperatur des Rußfilters bevorzugt etwa 200°C.Regarding the Process e) is the upper ammonia adsorption limit temperature of the soot filter preferably about 200 ° C.
Obige sowie weitere Merkmale und Vorteile der Erfindung werden aus der nachfolgenden Beschreibung eines bevorzugten, nicht-einschränkenden Ausführungsbeispiels der Erfindung unter Bezugnahme auf die beiliegenden Zeichnungen besser verständlich. Darin zeigen:Above and other features and advantages of the invention will become apparent from the following description of a preferred, non-limiting embodiment of the invention with reference to the accompanying drawings better understandable. Show:
In
Der
Dieselmotor
Die
Abgase des Dieselmotors
Andererseits
werden die Abgase aus dem Auspuffkrümmer
Die
Abgasreinigungsanlage
Die
zentrale Motorsteuerung
Da
der Aufbau und die grundsätzliche
Funktionsweise eines derartigen Dieselmotors
Nachfolgend
wird das Betriebsverfahren der oben anhand von
Grundsätzlich werden
in dem Stickoxidadsorptions- und Ammoniakerzeugungskatalysator (NSK)
Ein
Stickoxidadsorptions- und Ammoniakerzeugungskatalysator (NSK)
Ein
gealteter bzw. verschwefelter NSK
In
Abhängigkeit
des ermittelten Alterungszustandes des NSK
Liegen
die Temperaturen am NSK
Alternativ
oder zusätzlich
kann ein Lambdaverlauf während
der Regenerationsphase des NSK
Eine
zweite Möglichkeit
des zeitlich variablen Lambdaverlaufs für die Regenrationsphase des
NSK
Außerdem sollte
die Regenerationsstrategie des NSK
Wie
oben erwähnt,
kann bei einer Variante der Abgasreinigungsanlage
Sämtliche
oben beschriebenen Maßnahmen können einzeln
oder in einer zweifachen oder mehrfachen Kombination vorgenommen
werden, um eine Optimierung der Stickoxid-Umsetzung in der Abgasreinigungsanlage
mit NSK und nachgeschaltetem SCR-Katalysator
zu erreichen. Zu diesem Zweck muss der aktuelle Zustand der Abgasreinigungsanlage,
d.h. der Alterungszustand des NSK und die Temperaturen am NSK, am
SCR-Katalysator und ggf. am Rußfilter
Claims (12)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE102005005664A DE102005005664A1 (en) | 2005-02-08 | 2005-02-08 | Operating an internal combustion engine comprises e.g. adjusting the interval between and duration of rich phase operation in response to the age state of a storage catalyst |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE102005005664A DE102005005664A1 (en) | 2005-02-08 | 2005-02-08 | Operating an internal combustion engine comprises e.g. adjusting the interval between and duration of rich phase operation in response to the age state of a storage catalyst |
Publications (1)
Publication Number | Publication Date |
---|---|
DE102005005664A1 true DE102005005664A1 (en) | 2006-04-20 |
Family
ID=36120701
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Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
DE102005005664A Withdrawn DE102005005664A1 (en) | 2005-02-08 | 2005-02-08 | Operating an internal combustion engine comprises e.g. adjusting the interval between and duration of rich phase operation in response to the age state of a storage catalyst |
Country Status (1)
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DE (1) | DE102005005664A1 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102008025520A1 (en) * | 2008-05-28 | 2009-12-24 | Ford Global Technologies, LLC, Dearborn | Exhaust gas after-treatment device operating method, involves triggering regeneration stage by selectively considering standard state variable based on aging state of nitrogen oxide storage catalytic converter |
US20120180462A1 (en) * | 2009-10-09 | 2012-07-19 | Toyota Jidosha Kabushiki Kaisha | Exhaust purification system of internal combustion engine |
FR2999233A1 (en) * | 2012-12-11 | 2014-06-13 | Renault Sa | DEVICE AND METHOD FOR DIAGNOSING AN OXIDE TRAPPER OF NITROGEN |
-
2005
- 2005-02-08 DE DE102005005664A patent/DE102005005664A1/en not_active Withdrawn
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102008025520A1 (en) * | 2008-05-28 | 2009-12-24 | Ford Global Technologies, LLC, Dearborn | Exhaust gas after-treatment device operating method, involves triggering regeneration stage by selectively considering standard state variable based on aging state of nitrogen oxide storage catalytic converter |
DE102008025520B4 (en) * | 2008-05-28 | 2011-06-09 | Ford Global Technologies, LLC, Dearborn | A method for operating an exhaust aftertreatment device, and exhaust aftertreatment device |
CN101592060B (en) * | 2008-05-28 | 2013-09-18 | 福特环球技术公司 | Exhaust gas after-treatment device and method for operating the same |
US20120180462A1 (en) * | 2009-10-09 | 2012-07-19 | Toyota Jidosha Kabushiki Kaisha | Exhaust purification system of internal combustion engine |
FR2999233A1 (en) * | 2012-12-11 | 2014-06-13 | Renault Sa | DEVICE AND METHOD FOR DIAGNOSING AN OXIDE TRAPPER OF NITROGEN |
WO2014090485A1 (en) * | 2012-12-11 | 2014-06-19 | Renault S.A.S. | Device and method for diagnosing a nitrogen oxide trap |
KR20150091324A (en) * | 2012-12-11 | 2015-08-10 | 르노 에스.아.에스. | Device and method for diagnosing a nitrogen oxide trap |
KR102135304B1 (en) | 2012-12-11 | 2020-08-26 | 르노 에스.아.에스. | Device and method for diagnosing a nitrogen oxide trap |
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