DE4310962C1 - Common exhaust gas unit for several engines - has common exhaust pipe with branch pipes contg. individual SCR catalysts - Google Patents
Common exhaust gas unit for several engines - has common exhaust pipe with branch pipes contg. individual SCR catalystsInfo
- Publication number
- DE4310962C1 DE4310962C1 DE4310962A DE4310962A DE4310962C1 DE 4310962 C1 DE4310962 C1 DE 4310962C1 DE 4310962 A DE4310962 A DE 4310962A DE 4310962 A DE4310962 A DE 4310962A DE 4310962 C1 DE4310962 C1 DE 4310962C1
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- Prior art keywords
- exhaust gas
- scr
- common
- shut
- common exhaust
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Classifications
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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
- F01N3/10—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
- F01N3/18—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 methods of operation; Control
- F01N3/20—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 methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
- F01N3/2066—Selective catalytic reduction [SCR]
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
- B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
- B01D53/9404—Removing only nitrogen compounds
- B01D53/9409—Nitrogen oxides
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
- B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
- B01D53/9404—Removing only nitrogen compounds
- B01D53/9409—Nitrogen oxides
- B01D53/9431—Processes characterised by a specific device
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
- B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
- B01D53/9495—Controlling the catalytic process
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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
- 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
- F01N13/0093—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 the purifying devices are of the same type
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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
- F01N13/011—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
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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
- F01N13/08—Other arrangements or adaptations of exhaust conduits
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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
- F01N3/10—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
- F01N3/18—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 methods of operation; Control
- F01N3/20—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 methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
- F01N3/2006—Periodically heating or cooling catalytic reactors, e.g. at cold starting or overheating
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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
- F01N3/10—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
- F01N3/18—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 methods of operation; Control
- F01N3/20—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 methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
- F01N3/2053—By-passing catalytic reactors, e.g. to prevent overheating
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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
- F01N2240/02—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 heat exchanger
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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
- F01N2610/00—Adding substances to exhaust gases
- F01N2610/02—Adding substances to exhaust gases the substance being ammonia or urea
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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
- Y02T10/12—Improving ICE efficiencies
Abstract
Description
Es ist bekannt, zur Entstickung der Abgase von Brennkraftmaschinen, dem Abgas ein Reduktionsmittel zuzusetzen, zum Beispiel Ammoniak, das nach dem SCR-Verfahren in Gegenwart eines Katalysators mit Stickoxiden zu molekularem Stickstoff und Wasserdampf reagiert.It is known to denox the exhaust gases from Internal combustion engines to add a reducing agent to the exhaust gas, for example ammonia, which is present in the SCR process a catalyst with nitrogen oxides to molecular nitrogen and Water vapor reacts.
Eine Einrichtung zur Abgasentstickung nach dem SCR-Verfahren ist beispielsweise aus der nicht vorveröffentlichten Patentanmeldung mit der Aktennummer P 42 37 705.6 bekannt. Diese Einrichtung dient insbesondere dazu, das Abgas von mehreren, unabhängig voneinander betreibbaren Dieselmotoren zu reinigen. Dabei strömt das Abgas der Dieselmotoren in eine gemeinsame Abgasleitung mit einem gemeinsamen SCR-Katalysator. Anschließend gelangt das gereinigte Abgas in einen Oxidationskatalysator, der dazu dient, das in den Abgasen enthaltene, nicht umgesetzte gasförmige Reduktionsmittel umzusetzen, so daß die Umwelt nicht mit Reduktionsmittel belastet wird. Daneben dient der Oxidationskatalysator auch dazu, das Abgas von Kohlenwasserstoffen und Kohlenmonoxid zu reinigen. Die Zahl der gleichzeitig in Betrieb befindlichen Brennkraftmaschinen kann stark schwanken. Dabei muß der SCR-Katalysator auf den größtmöglichen Abgasvolumenstrom ausgelegt sein, der dem Betrieb aller an der Abgasanlage angeschlossenen Brennkraftmaschinen entspricht. Dies führt zu einem großen Bauvolumen des SCR-Katalysators mit einem trägen Verhalten in der Aufheizphase. A device for exhaust gas denitrification according to the SCR process is for example from the unpublished patent application known with file number P 42 37 705.6. This facility serves in particular to separate the exhaust gas from several to clean diesel engines that can be operated from one another. It flows the exhaust of the diesel engines in a common exhaust pipe a common SCR catalyst. Then it arrives cleaned exhaust gas in an oxidation catalytic converter, which serves to the unconverted gaseous contained in the exhaust gases Implement reducing agents so that the environment is not with Reducing agent is loaded. In addition, the Oxidation catalyst also to the exhaust of Clean hydrocarbons and carbon monoxide. The number of Internal combustion engines in operation at the same time fluctuate greatly. The SCR catalytic converter must be on the the largest possible exhaust gas volume flow to be designed for operation all internal combustion engines connected to the exhaust system corresponds. This leads to a large construction volume of the SCR catalyst with a sluggish behavior in the heating phase.
Da der SCR-Katalysator inaktiv ist, solange eine Mindesttemperatur nicht erreicht ist, ist der Zeitanteil, in dem keine Abgasreinigung erfolgt, dementsprechend groß.Since the SCR catalyst is inactive as long as one Minimum temperature is not reached is the percentage of time in which no exhaust gas cleaning takes place, accordingly large.
Die Abgasanlage nach der DE 40 03 515 A1 dient zur Ableitung des Abgases einer einzigen Brennkraftmaschine. Der benötigte SCR-Katalysator ist, da nur die Abgasmenge einer Brennkraftmaschine zu entsticken ist, kleiner und im Aufwärmverhalten weniger träge, als ein Katalysator für größere Abgasmengen, wie sie bei einer für mehrere Brennkraftmaschinen gemeinsamen Abgasanlage anfallen.The exhaust system according to DE 40 03 515 A1 is used to derive the Exhaust gas from a single internal combustion engine. The one needed SCR catalytic converter is only one since the amount of exhaust gas Internal combustion engine is smaller and smaller Warm-up behavior less sluggish than a catalyst for larger ones Exhaust gas quantities, as in one for several internal combustion engines common exhaust system.
Der im Patentanspruch 1 angegebenen Erfindung liegt das Problem zugrunde, den Zeitabschnitt, in dem keine Abgasreinigung erfolgt, bei einer für mehrere Brennkraftmaschinen gemeinsamen Abgasanlage erheblich zu verkürzen.The invention specified in claim 1 is the problem based on the period in which no exhaust gas purification takes place at a common for several internal combustion engines Shorten the exhaust system considerably.
Dieses Problem wird durch die im Patentanspruch 1 aufgeführten Merkmale gelöst. An Stelle eines trägen, großen SCR-Katalysators sind mehrere kleine SCR-Katalysatoren vorgesehen, die in von einer gemeinsamen Abgasleitung für alle Brennkraftmaschinen abzweigenden Zweigleitungen angeordnet sind. Die Zweigleitungen sind mit stellbaren Absperrventilen versehen, durch die die verschiedenen SCR-Katalysatoren abhängig vom Lastzustand der Brennkraftmaschinen, und damit abhängig vom Gesamtabgasvolumenstrom zu- oder abgeschaltet werden können. Wenn nur ein Teil der mit der gemeinsamen Abgasanlage verbundenen Brennkraftmaschinen in Betrieb ist, wird auch nur ein Teil der SCR-Katalysatoren zur Abgasreinigung benötigt. Wegen der geringeren zu erwärmenden Masse der kleineren SCR-Katalysatoren wird die Aufheizphase verkürzt, und dementsprechend früher kann die Abgasreinigung durch selektive katalytische Reduktion beginnen. Nach Anspruch 2 wird das von einem zugeschaltetem SCR-Katalysator abströmende, gereinigte Abgas über eine Verbindungsleitung in die Zweigleitung vor denjenigen SCR-Katalysator zugeleitet, der bei einer weiteren Zunahme des Abgasvolumenstroms, also beispielsweise bei Hochfahren eines zusätzlichen Motors, als nächster zur Zuschaltung vorgesehen ist. Dadurch wird dieser SCR-Katalysator vorgewärmt, der dann, wenn der Gesamtabgasvolumenstrom die Kapazität der zugeschalteten SCR-Katalysatoren überschreitet, sofort einsatzbereit für die Abgasentstickung ist. Nach Anspruch 3 sind zweckmäßigerweise jeweils die Zweigleitungen zweier nacheinander zur Zuschaltung kommenden SCR-Katalysatoren durch Verbindungsleitungen mit stellbaren Absperrventilen miteinander verbunden. Zur Umsetzung von überschüssigem Reduktionsmittel im gereinigten Abgas, kann nach Anspruch 4 ein gemeinsamer Oxidationskatalysator in einer gemeinsamen Leitung liegen, in die alle Zweigleitungen münden. Nach Anspruch 5 kann auch jeweils in jeder Zweigleitung im Anschluß an jeden SCR-Katalysator ein Oxidationskatalysator angeordnet sein.This problem is caused by those listed in claim 1 Features resolved. Instead of a sluggish, large SCR catalytic converter several small SCR catalysts are provided, which are in from a common exhaust pipe for all internal combustion engines branching branch lines are arranged. The branch lines are equipped with adjustable shut-off valves, through which the different SCR catalysts depending on the load state of the Internal combustion engines, and therefore depending on Total exhaust gas volume flow can be switched on or off. If only part of that with the common exhaust system connected internal combustion engines is in operation, too some of the SCR catalytic converters are required for exhaust gas purification. Because of the smaller mass to be heated, the smaller ones SCR catalysts, the heating phase is shortened, and Accordingly, the exhaust gas cleaning can be done earlier by selective start catalytic reduction. According to claim 2, that of a cleaned SCR catalytic converter flowing out Exhaust gas via a connecting line into the branch line the SCR catalytic converter supplied to another Increase in the exhaust gas volume flow, for example at Start up an additional motor, next to Connection is provided. This will make this SCR catalyst preheated when the total exhaust gas volume flow Capacity of the connected SCR catalysts exceeds is immediately ready for use in exhaust gas denitrification. According to claim 3 are expediently the branch lines of two SCR catalytic converters that are switched on one after the other Connection lines with adjustable shut-off valves with each other connected. To implement excess reducing agent in the cleaned exhaust gas, according to claim 4, a common Oxidation catalyst are in a common line, in that open all branch lines. According to claim 5 can also in each branch line following each SCR catalyst can be arranged an oxidation catalyst.
Ein Ausführungsbeispiel der Erfindung ist in der Zeichnung dargestellt und wird im folgenden näher beschrieben. Es zeigenAn embodiment of the invention is in the drawing shown and is described in more detail below. Show it
Fig. 1 eine Schemadarstellung einer Abgasanlage für drei Brennkraftmaschinen mit drei SCR-Katalysatoren in drei Zweigleitungen; Figure 1 is a schematic representation of an exhaust system for three internal combustion engines with three SCR catalysts in three branch lines.
Fig. 2 eine Anordnung mit zwei SCR-Katalysatoren und jedem SCR-Katalysator nachgeschaltetem Oxidationskatalysator in einem gemeinsamen Gehäuse; Figure 2 shows an arrangement with two SCR catalysts and each SCR catalyst downstream oxidation catalyst in a common housing.
Fig. 3 eine Fig. 2 entsprechende Anordnung mit zwei SCR-Katalysatoren in einem gemeinsamen Gehäuse, mit einem gemeinsamen nachgeschalteten Oxidationskatalysator. Fig. 3 is a Fig. 2 corresponding arrangement with two SCR catalysts in a common housing with a common downstream oxidation catalyst.
In der Fig. 1 ist ein Anordnungsschema mit drei unabhängig voneinander betreibbaren Brennkraftmaschinen 1, 2 und 3 dargestellt, deren Abgas über die Abgasleitungen 4, 5 und 6 in eine gemeinsame Abgasleitung 7 gelangt. Die Abgasleitung 7 verzweigt sich in drei Zweigleitungen 7a, 7b und 7c, denen SCR-Katalysatoren 14, 15 und 16 zugeordnet sind. Die SCR-Katalysatoren 14, 15 und 16 dienen zur selektiven katalytischen Reduktion von Stickoxiden aus dem Abgas. In den SCR-Katalysatoren 14, 15 und 16 wird das im Abgas enthaltene Stickoxid mit dem Reduktionsmittel, in der Regel Ammoniak, zu molekularem Stickstoff und Wasserdampf reagiert. In einem nachgeschaltetem Oxidationskatalysator 17, der in einer Leitung 13 angeordnet ist, erfolgt die Neutralisierung des bei der Stickoxid-Reduktion nicht verbrauchten Reduktionsmittels. In FIG. 1, an arrangement scheme is shown with three independently operable internal combustion engines 1, 2 and 3, the exhaust gas passes through the exhaust pipes 4, 5 and 6 in a common exhaust pipe 7. The exhaust line 7 branches into three branch lines 7 a, 7 b and 7 c, to which SCR catalysts 14 , 15 and 16 are assigned. The SCR catalysts 14 , 15 and 16 are used for the selective catalytic reduction of nitrogen oxides from the exhaust gas. In the SCR catalytic converters 14 , 15 and 16 , the nitrogen oxide contained in the exhaust gas is reacted with the reducing agent, usually ammonia, to form molecular nitrogen and water vapor. In a downstream oxidation catalytic converter 17 , which is arranged in a line 13 , the reducing agent not consumed in the nitrogen oxide reduction is neutralized.
Zur Zufuhr des Reduktionsmittels ist in der gemeinsamen Abgasleitung 7 eine Reduktionsmittel-Zugabevorrichtung 20 angeordnet, an die über eine Reduktionsmittelleitung 21 ein Reduktionsmittelspeicher 18 angeschlossen ist. Ein in der Reduktionsmittelleitung 21 angeordnetes Dosierventil 19 ist von einer Steuervorrichtung 22 derart steuerbar, daß ein dem momentanen Stickoxidgehalt des Abgases angepaßter Reduktionsmittelstrom dem Abgas beigemischt wird. Zur Ermittlung der notwendigen Reduktionsmittelmenge dienen Sensoren, mit deren Hilfe verschiedene Motorbetriebskennwerte gemessen werden, die eine Aussage über den Lastzustand der Brennkraftmaschinen 1, 2 und 3 und die Abgaszusammensetzung zulassen. Die Sensoren stehen über gestrichelt dargestellte Steuerleitungen mit der Steuervorrichtung 22 in Verbindung. Die Steuervorrichtung 22 ist über weitere Steuerleitungen mit den Betätigungsmotoren (M) von Absperrventilen 23 und 24 verbunden, die in den Zweigleitungen 7c und 7b angeordnet sind. Ergibt sich aus den durch Sensoren gemessenen Motorbetriebskennwerten, daß das Gesamtabgasvolumen so gering ist, daß es vollständig in einem SCR-Katalysator 14 gereinigt werden kann, so bleiben die als Klappenventile ausgebildeten Absperrventile 23 und 24 wie dargestellt geschlossen. Das gesamte Abgas wird im SCR-Katalysator 14 entstickt. Das entstickte, den SCR-Katalysator 14 verlassende Abgas gelangt über ein weiteres Absperrventil 27 in einer Verbindungsleitung 11 vor den SCR-Katalysator 15 und durchströmt diesen. Dazu ist im weiteren ein in der Zweigleitung 7a hinter der Abzweigung der Verbindungsleitung 11 angeordnetes Absperrventil 25 geschlossen und ein in der Zweigleitung 7b angeordnetes weiteres Absperrventil 26 durch Einwirkung der Steuervorrichtung 22 geöffnet. Es wird dadurch erreicht, daß der SCR-Katalysator 15 von dem ihn durchströmenden, entstickten Abgasvolumenstrom vorgewärmt wird. Erreicht nun der Abgasvolumenstrom eine Größe, die nicht mehr im SCR-Katalysator 14 allein gereinigt werden kann, wird der Abgasstrom auf die SCR-Katalysatoren 14 und 15 aufgeteilt. Durch die Steuereinrichtung 22 wird dann das Absperrventil 24 geöffnet, während zugleich das Absperrventil 27 in der Verbindungsleitung 11 geschlossen, und das Absperrventil 25 in der Zweigleitung 7a geöffnet wird. Das vom SCR-Katalysator 14 abströmende Abgas wird dann direkt zum Oxidationskatalysator 17 in die Leitung 13 geleitet. Das aus dem SCR-Katalysator 15 abströmende gereinigte Abgas kann nun dazu verwendet werden, den weiteren SCR-Katalysator 16 vorzuwärmen. Dazu wird das Absperrventil 26 in der Zweigleitung 7b - wie jedoch nicht dargestellt - geschlossen und ein Absperrventil 28 in einer Verbindungsleitung 12 geöffnet. Bei weiterer Zunahme des Abgasvolumenstroms ist dann auch der SCR-Katalysator 16 bereits vorgewärmt, wenn dieser durch Öffnen des Absperrventils 23 zugeschaltet, d. h. in Betrieb genommen wird. Die Anzahl der SCR-Katalysatoren kann natürlich auch größer sein, je nachdem, wieviele Brennkraftmaschinen mit der Abgasanlage verbunden sind. Der Vorteil von mehreren kleinen SCR-Katalysatoren an Stelle eines großen SCR-Katalysators ist, daß diese schneller auf Betriebstemperatur sind, und dadurch der Zeitabschnitt, in dem keine Abgasreinigung erfolgt, entsprechend klein ist. Dieser Vorteil ergibt sich insbesondere dann, wenn die mit der Abgasanlage verbundenen Brennkraftmaschinen nicht gleichzeitig hochgefahren werden. Dies ist beispielsweise bei Motorenprüfständen der Fall. Die Anzahl der in Betrieb befindlichen Brennkraftmaschinen schwankt stark. Durch Vorheizung der jeweils als nächsten zur Zuschaltung kommenden SCR-Katalysators ist hier die Abgasreinigung besonders effektiv.To supply the reducing agent, a reducing agent addition device 20 is arranged in the common exhaust gas line 7 , to which a reducing agent storage device 18 is connected via a reducing agent line 21 . A metering valve 19 arranged in the reducing agent line 21 can be controlled by a control device 22 such that a reducing agent flow adapted to the instantaneous nitrogen oxide content of the exhaust gas is admixed to the exhaust gas. Sensors are used to determine the required amount of reducing agent, with the aid of which various engine operating parameters are measured, which allow a statement about the load state of the internal combustion engines 1 , 2 and 3 and the exhaust gas composition. The sensors are connected to the control device 22 via control lines shown in dashed lines. The control device 22 is connected via further control lines to the actuating motors (M) of shut-off valves 23 and 24 , which are arranged in the branch lines 7 c and 7 b. If it results from the engine operating parameters measured by sensors that the total exhaust gas volume is so small that it can be completely cleaned in an SCR catalytic converter 14 , the shut-off valves 23 and 24 designed as flap valves remain closed as shown. All of the exhaust gas is denitrified in the SCR catalytic converter 14 . The denitrified exhaust gas leaving the SCR catalytic converter 14 reaches the SCR catalytic converter 15 via a further shut-off valve 27 in a connecting line 11 and flows through it. For this purpose, a shut-off valve 25 arranged in the branch line 7 a behind the branch of the connecting line 11 is closed and a further shut-off valve 26 arranged in the branch line 7 b is opened by the action of the control device 22 . It is achieved in that the SCR catalytic converter 15 is preheated by the denitrified exhaust gas volume flow flowing through it. If the exhaust gas volume flow now reaches a size that can no longer be cleaned in the SCR catalytic converter 14 alone, the exhaust gas flow is divided between the SCR catalytic converters 14 and 15 . The shut-off valve 24 is then opened by the control device 22 , while at the same time the shut-off valve 27 in the connecting line 11 is closed and the shut-off valve 25 in the branch line 7 a is opened. The exhaust gas flowing out of the SCR catalytic converter 14 is then passed directly to the oxidation catalytic converter 17 in the line 13 . The cleaned exhaust gas flowing out of the SCR catalytic converter 15 can now be used to preheat the further SCR catalytic converter 16 . For this purpose, the shut-off valve 26 in the branch line 7 b is closed, but not shown, and a shut-off valve 28 in a connecting line 12 is opened. With a further increase in the exhaust gas volume flow, the SCR catalytic converter 16 is already preheated when it is switched on by opening the shut-off valve 23 , ie is put into operation. The number of SCR catalytic converters can of course also be larger, depending on how many internal combustion engines are connected to the exhaust system. The advantage of using several small SCR catalytic converters instead of one large SCR catalytic converter is that they are faster to the operating temperature and the time period in which no exhaust gas cleaning takes place is correspondingly short. This advantage arises in particular when the internal combustion engines connected to the exhaust system are not started up at the same time. This is the case with engine test benches, for example. The number of internal combustion engines in operation fluctuates greatly. By preheating the next SCR catalytic converter to be switched on, exhaust gas purification is particularly effective here.
Bei der in den Fig. 2 und 3 dargestellten Abgasanlage sind die SCR-Katalysatoren 30 und 31, die aus Teilkatalysatoren 30a, 30b, 30c und 31a, 31b und 31c bestehen, in einem gemeinsamen Gehäuse angeordnet. Zum Vorwärmen des Katalysators 31 kann das aus dem SCR-Katalysator 30 abströmende gereinigte Abgas über eine Verbindungsleitung 36, die als Gehäusekanal ausgebildet ist, vor den SCR-Katalysator 31 zurückgeführt werden. Die eingezeichneten Pfeile verdeutlichen die Strömung des Abgases. Das Absperrventil 35, das durch eine Steuervorrichtung 22 nach Fig. 1 betätigt werden kann, ist dann so gestellt, daß das vom SCR-Katalysator 30 abströmende Abgas nicht unmittelbar in die Leitung 13 gelangt. Nimmt das Abgasvolumen zu, so daß es im SCR-Katalysator 30 allein nicht mehr entstickt werden kann, wird das Absperrventil 34 geöffnet und so der ungereinigte Abgasstrom aus der Abgasleitung 7 auf die Zweigleitungen 7a und 7b verteilt. Das Absperrventil 35 befindet sich dann in der gestrichelt dargestellten Stellung, in der eine Rückströmung in die Verbindungsleitung 36 ausgeschlossen ist.In the exhaust system shown in FIGS . 2 and 3, the SCR catalysts 30 and 31 , which consist of partial catalysts 30 a, 30 b, 30 c and 31 a, 31 b and 31 c, are arranged in a common housing. To preheat the catalyst 31, the flowing out of the SCR catalyst 30 purified exhaust gas through a connecting line 36, which is constructed as a housing channel, are recycled upstream of the SCR catalyst 31st The arrows show the flow of the exhaust gas. The shut-off valve 35 , which can be actuated by a control device 22 according to FIG. 1, is then set such that the exhaust gas flowing out of the SCR catalytic converter 30 does not get directly into the line 13 . If the exhaust gas volume increases so that it can no longer be denitrified in the SCR catalytic converter 30 alone, the shut-off valve 34 is opened and the uncleaned exhaust gas stream from the exhaust gas line 7 is distributed to the branch lines 7 a and 7 b. The shut-off valve 35 is then in the position shown in broken lines, in which a backflow into the connecting line 36 is excluded.
Bei der Abgasanlage nach Fig. 2 sind in jeder Zweigleitung 7a und 7b in Strömungsrichtung hinter jedem SCR-Katalysator 30, 31 ein Oxidationskatalysator 32a bzw. 32b angeordnet. Bei dieser Anordnung kann es bei der beschriebenen Vorwärmung des SCR-Katalysator 31 im Oxidationskatalysator 32a zur Oxidation von SO2 und SO3 kommen. Diese Komponenten können in noch kalten Bereichen des aufzuwärmenden SCR-Katalysators 31 mit dem Wasserdampf des Abgases zu Schwefelsäure auskondensieren. Um dies zu vermeiden ist es vorteilhaft die Oxidationskatalysatoren nicht jeweils einem SCR-Katalysator nachfolgend anzuordnen wie in Fig. 2 dargestellt, sondern wie in Fig. 3 dargestellt in einer gemeinsamen Leitung 13, in die das aus den Zweigleitungen 7a und 7b abströmende Abgas gelangt.In the exhaust system according to FIG. 2, an oxidation catalytic converter 32 a and 32 b are arranged in each branch line 7 a and 7 b in the flow direction behind each SCR catalytic converter 30 , 31 . With this arrangement, the described preheating of the SCR catalytic converter 31 in the oxidation catalytic converter 32 a can lead to the oxidation of SO 2 and SO 3 . In still cold areas of the SCR catalytic converter 31 to be warmed up, these components can condense with the water vapor of the exhaust gas to give sulfuric acid. In order to avoid this, it is advantageous not to arrange the oxidation catalysts in each case downstream of an SCR catalyst, as shown in FIG. 2, but, as shown in FIG. 3, in a common line 13 , into which the exhaust gas flowing out of the branch lines 7 a and 7 b reached.
Claims (5)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE4310962A DE4310962C1 (en) | 1993-04-03 | 1993-04-03 | Common exhaust gas unit for several engines - has common exhaust pipe with branch pipes contg. individual SCR catalysts |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE4310962A DE4310962C1 (en) | 1993-04-03 | 1993-04-03 | Common exhaust gas unit for several engines - has common exhaust pipe with branch pipes contg. individual SCR catalysts |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| DE4310962C1 true DE4310962C1 (en) | 1994-02-10 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| DE4310962A Expired - Fee Related DE4310962C1 (en) | 1993-04-03 | 1993-04-03 | Common exhaust gas unit for several engines - has common exhaust pipe with branch pipes contg. individual SCR catalysts |
Country Status (1)
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|---|---|
| DE (1) | DE4310962C1 (en) |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0758714A1 (en) * | 1995-08-12 | 1997-02-19 | Adam Opel Ag | Exhaust line of a spark ignition engine |
| WO1999024152A1 (en) * | 1997-11-10 | 1999-05-20 | Siemens Aktiengesellschaft | Process and device for reducing the number of particles in combustion gas |
| DE10150267A1 (en) * | 2001-10-11 | 2003-04-30 | Opel Adam Ag | Selective catalytic reduction catalyst operation, comprises supplying the catalyst with unburnt hydrocarbons or carbon monoxide to convert nitrogen oxides |
| EP1876331A3 (en) * | 2006-07-08 | 2008-01-23 | MAN Nutzfahrzeuge AG | Assembly for reducing nitrogen oxides in exhaust gases |
| EP1882832A2 (en) * | 2006-07-08 | 2008-01-30 | MAN Nutzfahrzeuge AG | Assembly for reducing nitrogen oxides in exhaust gases |
| WO2014057165A1 (en) | 2012-10-09 | 2014-04-17 | Wärtsilä Finland Oy | Catalyst unit for internal combustion piston engine |
| DE102012018141A1 (en) | 2012-09-14 | 2014-05-15 | Mtu Friedrichshafen Gmbh | SCR module |
| DE102012018139A1 (en) | 2012-09-14 | 2014-05-15 | Mtu Friedrichshafen Gmbh | Internal combustion engine system for e.g. agricultural vehicle, has reducing agent interface including screw and/or plug-in connector for hydraulic connection with reducing agent tank and reducing agent mating interface |
| DE102014005515A1 (en) * | 2014-04-15 | 2015-10-15 | Man Diesel & Turbo Se | Combustion engine system and method and controller for operating the same |
| CN107630736A (en) * | 2017-11-10 | 2018-01-26 | 潍柴动力股份有限公司 | A kind of multichip carrier SCR assemblies and its method of work |
| CN107654278A (en) * | 2016-07-25 | 2018-02-02 | 福特环球技术公司 | Method and system for exhaust aftertreatment |
| EP4212708A1 (en) * | 2022-01-17 | 2023-07-19 | Volvo Truck Corporation | A method for controlling an exhaust flow in an exhaust aftertreatment system (eats) of a vehicle |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4003515A1 (en) * | 1990-02-06 | 1991-08-08 | Bayer Ag | METHOD FOR REDUCING NITROGEN OXIDS CONTAINED IN EXHAUST GAS |
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1993
- 1993-04-03 DE DE4310962A patent/DE4310962C1/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4003515A1 (en) * | 1990-02-06 | 1991-08-08 | Bayer Ag | METHOD FOR REDUCING NITROGEN OXIDS CONTAINED IN EXHAUST GAS |
Cited By (24)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0758714A1 (en) * | 1995-08-12 | 1997-02-19 | Adam Opel Ag | Exhaust line of a spark ignition engine |
| WO1999024152A1 (en) * | 1997-11-10 | 1999-05-20 | Siemens Aktiengesellschaft | Process and device for reducing the number of particles in combustion gas |
| US6941742B1 (en) | 1997-11-10 | 2005-09-13 | Siemens Aktiengesellschaft | Method and device for reducing the number of particles in an exhaust gas |
| DE10150267A1 (en) * | 2001-10-11 | 2003-04-30 | Opel Adam Ag | Selective catalytic reduction catalyst operation, comprises supplying the catalyst with unburnt hydrocarbons or carbon monoxide to convert nitrogen oxides |
| EP1882832A3 (en) * | 2006-07-08 | 2008-02-06 | MAN Nutzfahrzeuge AG | Assembly for reducing nitrogen oxides in exhaust gases |
| EP1882832A2 (en) * | 2006-07-08 | 2008-01-30 | MAN Nutzfahrzeuge AG | Assembly for reducing nitrogen oxides in exhaust gases |
| US8398943B2 (en) | 2006-07-08 | 2013-03-19 | Man Truck & Bus Ag | Arrangement for reducing nitrogen oxides in exhaust gases |
| EP1876331A3 (en) * | 2006-07-08 | 2008-01-23 | MAN Nutzfahrzeuge AG | Assembly for reducing nitrogen oxides in exhaust gases |
| DE102012018139B4 (en) * | 2012-09-14 | 2016-10-20 | Mtu Friedrichshafen Gmbh | Reducing agent interface |
| DE102012018141A1 (en) | 2012-09-14 | 2014-05-15 | Mtu Friedrichshafen Gmbh | SCR module |
| DE102012018139A1 (en) | 2012-09-14 | 2014-05-15 | Mtu Friedrichshafen Gmbh | Internal combustion engine system for e.g. agricultural vehicle, has reducing agent interface including screw and/or plug-in connector for hydraulic connection with reducing agent tank and reducing agent mating interface |
| US9562459B2 (en) | 2012-09-14 | 2017-02-07 | Mtu Friedrichshafen Gmbh | SCR-module |
| DE102012018141B4 (en) * | 2012-09-14 | 2016-10-20 | Mtu Friedrichshafen Gmbh | SCR module |
| WO2014057165A1 (en) | 2012-10-09 | 2014-04-17 | Wärtsilä Finland Oy | Catalyst unit for internal combustion piston engine |
| CN105041428A (en) * | 2014-04-15 | 2015-11-11 | 曼柴油机和涡轮机欧洲股份公司 | Internal combustion power machine system and method and control device for operating the same |
| JP2015203418A (en) * | 2014-04-15 | 2015-11-16 | マン・ディーゼル・アンド・ターボ・エスイー | Internal combustion engine system, method of operating internal combustion engine system, and operation control device |
| DE102014005515A1 (en) * | 2014-04-15 | 2015-10-15 | Man Diesel & Turbo Se | Combustion engine system and method and controller for operating the same |
| DK179059B1 (en) * | 2014-04-15 | 2017-09-25 | Man Diesel & Turbo Se | System af kraftmaskiner med indvendig forbrænding og styreindretning til styring heraf |
| CN105041428B (en) * | 2014-04-15 | 2019-07-02 | 曼恩能源方案有限公司 | Combustion power machine system and method and control device for operating on it |
| CN107654278A (en) * | 2016-07-25 | 2018-02-02 | 福特环球技术公司 | Method and system for exhaust aftertreatment |
| CN107630736A (en) * | 2017-11-10 | 2018-01-26 | 潍柴动力股份有限公司 | A kind of multichip carrier SCR assemblies and its method of work |
| CN107630736B (en) * | 2017-11-10 | 2020-06-26 | 潍柴动力股份有限公司 | Multi-carrier SCR assembly and working method thereof |
| EP4212708A1 (en) * | 2022-01-17 | 2023-07-19 | Volvo Truck Corporation | A method for controlling an exhaust flow in an exhaust aftertreatment system (eats) of a vehicle |
| US11952932B2 (en) | 2022-01-17 | 2024-04-09 | Volvo Truck Corporation | Method for controlling an exhaust flow in an exhaust aftertreatment system (EATS) of a vehicle |
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