EP0313922B1 - Method for influencing the exhaust gas temperature, and exhaust apparatus to carry out the method - Google Patents

Method for influencing the exhaust gas temperature, and exhaust apparatus to carry out the method Download PDF

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Publication number
EP0313922B1
EP0313922B1 EP88116975A EP88116975A EP0313922B1 EP 0313922 B1 EP0313922 B1 EP 0313922B1 EP 88116975 A EP88116975 A EP 88116975A EP 88116975 A EP88116975 A EP 88116975A EP 0313922 B1 EP0313922 B1 EP 0313922B1
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EP
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Prior art keywords
exhaust
exhaust gas
gas
catalyst
gas system
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German (de)
French (fr)
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EP0313922A1 (en
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Wolfgang Semet
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Bayerische Motoren Werke AG
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Bayerische Motoren Werke AG
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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

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  • the invention relates to a method for influencing the temperature of exhaust gases in the inlet area of an exhaust gas catalytic converter provided in an exhaust gas system, a quantity-controlled internal combustion engine, and to an exhaust gas system for carrying out this method.
  • Exhaust gas catalysts or the exhaust gases of an internal combustion engine to be cleaned therein require a certain operating temperature for the successful conversion of harmful exhaust gas components, which should not fall below a lower threshold value and should always be below an upper limit value. If the upper limit value is exceeded, the degree of conversion of an exhaust gas catalytic converter deteriorates due to thermal aging; if extremely high temperature peaks occur, even melting of the monolith arranged in the exhaust gas catalytic converter can occur. On the other hand, it is necessary to bring the exhaust gas catalytic converter to the minimum operating temperature required for a successful conversion within the shortest possible time.
  • a method for generating an optimal exhaust gas inlet temperature for the exhaust gas catalytic converter of internal combustion engines has become known from the generic DE-OS 3 406 968.
  • the engine exhaust is divided into two partial flows, one of which is cooled and the other is not cooled; the partial streams are reunited upstream of the catalyst and the catalyst temperature is regulated by changing the quantitative ratio of the two partial streams.
  • the object of the present invention is to demonstrate a method according to the preamble of the first claim, which requires a construction work that is significantly reduced compared to the known method. This object is achieved by the characterizing features of the first claim.
  • an exhaust gas partial flow removed from the exhaust gas system downstream of the exhaust gas catalytic converter is introduced into the exhaust gas system upstream of the exhaust gas catalytic converter, effective cooling of the exhaust gas in the inlet area of the exhaust gas catalytic converter can be achieved with this partial flow.
  • the return line required for the partial flow can be made extremely simple: only a small space requirement is required since only one partial flow is carried.
  • complex cooling measures can be dispensed with, since the cooling effect achieved over the return path is sufficient for the desired temperature reduction after the partial flow has been introduced into the exhaust system.
  • a partial exhaust gas stream taken downstream of the soot filter is also used for exhaust gas cooling.
  • a heat exchanger is provided for this.
  • the cooling exhaust gas flow is fed to the intake tract of the internal combustion engine.
  • the exhaust gas partial flow downstream of the exhaust gas catalytic converter does not contain any free oxygen, after the partial flow has been introduced into the exhaust gas system, any unburned hydrocarbons which may be present in the exhaust gas stream cannot damage the catalyst. If there is an oxygen probe in the exhaust system, with the aid of which the internal combustion engine is operated with a stoichiometric mixture for optimal conversion of the exhaust gas in the exhaust gas catalytic converter, the measurement result thereof is also not influenced by the exhaust gas partial flow returned for cooling purposes, since this partial flow, if it is downstream of the Exhaust gas catalyst is removed, can not contain free oxygen.
  • the partial stream can thus be added to the exhaust gas upstream of the oxygen probe, so that the probe is also subjected to lower exhaust gas temperatures.
  • the method according to the invention is also advantageous with regard to the conversion of harmful exhaust gas constituents: because the exhaust gas catalytic converter flows through at least one partial exhaust gas stream twice, a tendency to reduce the exhaust gas emissions that can still be measured after the catalytic converter can be determined.
  • the partial flow amount required for the required exhaust gas cooling can be determined and made available, for example depending on the exhaust gas temperature determined by means of a temperature sensor upstream of the exhaust gas catalytic converter.
  • an exhaust system for carrying out the method according to the invention are described in claims 3 to 7. Accordingly, a simple return line without complex additional measures can be provided for the partial exhaust gas flow if a check valve is provided in this return line.
  • the check valve prevents the exhaust gases from leaving the exhaust system upstream of the exhaust gas catalytic converter.
  • the path for the partial flow taken downstream of the exhaust gas catalytic converter is released in the case of negative pressure, and the partial flow is thus automatically conveyed upstream of the exhaust gas catalytic converter into the exhaust system.
  • a throttle element which controls the quantity of the partial exhaust gas flow can be added for example in the form of a clocking solenoid valve.
  • the element provided in the return line can be designed as a conveying device for the recirculated exhaust gas partial flow.
  • Conveying devices of this type for example pumps or small flow compressors, convey the desired partial exhaust gas stream upstream of the exhaust gas catalytic converter back into the exhaust system at operating points of the internal combustion engine in which the exhaust gas pressure downstream of the exhaust gas catalytic converter is not sufficient.
  • the conveying device can take over the function of the check valve and of the throttle element.
  • An exhaust gas system designated in its entirety by 2 is flanged to an internal combustion engine 1. This consists of two elbows 3a, 3b, an adjoining exhaust pipe 4, in which an oxygen sensor 5 is arranged, and which opens into the exhaust gas analyzer 6. This is followed by a rear silencer 7 via a pipe connection.
  • two return lines 8a, 8b branch off from the exhaust system 2 between the catalytic converter 6 and the rear muffler 7 and open into the manifolds 3a, 3b.
  • a check valve 9 and a solenoid valve 10 are arranged in the return line 8a.
  • the check valve 9 prevents exhaust gas from passing through the return line 8 against the arrow direction 11 directly from the manifold 3a to the rear silencer 7.
  • Another embodiment is implemented in the exhaust line 8b, which contains a conveyor device 12 for the exhaust gas partial flow to be recycled.
  • the conveying device 12 controllably conveys a partial exhaust gas flow in the direction of the arrow 11 to the manifold 3b.
  • Those partial flows cool down in particular in the return lines 8 to such an extent that the exhaust gas flow emitted by the internal combustion engine 1 is reduced to a level compatible with the catalytic converter 6 by admixing these partial flows with its temperature.
  • the solenoid valve 10 or the conveyor device 12 By appropriate activation of the solenoid valve 10 or the conveyor device 12, the partial flows guided via the return lines 8 can be controlled in such a quantity that the temperature level reaches a desired value after being brought together in the elbows 3 or in the exhaust pipe 4.
  • This temperature level can be determined, for example, by a temperature sensor, not shown, which engages the solenoid valve 10 or the conveying device 12 via a control unit, also not shown.
  • the exemplary embodiment shown merely represents a possible exhaust system for carrying out the method according to the invention for influencing the temperature of exhaust gases; Modifications from this are easily conceivable.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Exhaust Gas After Treatment (AREA)
  • Exhaust Silencers (AREA)

Description

Die Erfindung bezieht sich auf ein Verfahren zur Beeinflussung der Temperatur von Abgasen im Eintrittsbereich eines in einer Abgasanlage vorgesehenen Abgas-Katalysators, einer quantitatov gesteuerten Brennkraftmaschine, sowie auf eine Abgasanlage zur Durchführung dieses Verfahrens.The invention relates to a method for influencing the temperature of exhaust gases in the inlet area of an exhaust gas catalytic converter provided in an exhaust gas system, a quantity-controlled internal combustion engine, and to an exhaust gas system for carrying out this method.

Abgas-Katalysatoren bzw. die darin zu reinigenden Abgase einer Brennkraftmaschine benötigen zur erfolgreichen Konvertierung schädlicher Abgasbestandteile eine gewisse Betriebstemperatur, welche einen unteren Schwellwert nicht unterschreiten sollte und stets unterhalb eines oberen Grenzwertes liegen sollte. Bei überschreiten des oberen Grenzwertes verschlechtert sich der Konvertierungsgrad eines Abgaskatalysators aufgrund thermischer Alterung; bei Auftreten von extrem hohen Temperaturspitzen können sogar Anschmelzungen des im Abgaskatalysator angeordneten Monolithen auftreten. Andererseits ist es erforderlich, den Abgaskatalysator nach einem Start der Brennkraftmaschine binnen kürzestmöglicher Zeit auf die für eine erfolgreiche Konvertierung erforderliche minimale Betriebstemperatur zu bringen.Exhaust gas catalysts or the exhaust gases of an internal combustion engine to be cleaned therein require a certain operating temperature for the successful conversion of harmful exhaust gas components, which should not fall below a lower threshold value and should always be below an upper limit value. If the upper limit value is exceeded, the degree of conversion of an exhaust gas catalytic converter deteriorates due to thermal aging; if extremely high temperature peaks occur, even melting of the monolith arranged in the exhaust gas catalytic converter can occur. On the other hand, it is necessary to bring the exhaust gas catalytic converter to the minimum operating temperature required for a successful conversion within the shortest possible time.

Ein Verfahren zur Erzeugung einer optimalen Abgaseingangstemperatur für den Abgaskatalysator von Verbrennungsmotoren ist aus der gattungsbildenden DE-OS 3 406 968 bekannt geworden. Dabei wird das Motorabgas in zwei Teilströme geteilt, von denen einer gekühlt und der andere nicht gekühlt wird; die Teilströme werden vor dem Katalysator wieder vereinigt und die Katalysatortemperatur wird durch Veränderung des Mengenverhältnisses der beiden Teilströme geregelt.A method for generating an optimal exhaust gas inlet temperature for the exhaust gas catalytic converter of internal combustion engines has become known from the generic DE-OS 3 406 968. The engine exhaust is divided into two partial flows, one of which is cooled and the other is not cooled; the partial streams are reunited upstream of the catalyst and the catalyst temperature is regulated by changing the quantitative ratio of the two partial streams.

Obgleich jenes bekannte Verfahren brauchbare Resultate liefert, so ist es doch in der Ausführung mit großem Aufwand verbunden. Erforderlich sind dabei nämlich zwei separate Abgasleitungen, welche jeweils den gesamten anfallenden Abgasstrom aufzunehmen vermögen, wobei für den zu kühlenden Abgasstrom den Platzbedarf erhöhende aufwendige Kühlmaßnahmen erforderlich sind. Desweiteren wird ein insbesondere hinsichtlich der Abdichtung aufwendiger Umschaltmechanismus benötigt, um den Abgasstrom wunschgemäß auf die beiden verschiedenen Abgasleitungen aufteilen zu können.Although that known method gives usable results, it is very expensive to implement. This is because two separate exhaust gas lines are required, each of which is able to absorb the entire resulting exhaust gas flow, and complex cooling measures which increase the space required are required for the exhaust gas flow to be cooled. Furthermore, a switching mechanism, which is particularly complex with regard to the sealing, is required in order to be able to divide the exhaust gas flow between the two different exhaust gas lines as desired.

Aufgabe der vorliegenden Erfindung ist es, ein Verfahren gemäß dem Oberbegriff des ersten Anspruchs aufzuzeigen, welches zur Durchführung einen gegenüber dem bekannten Verfahren deutlich reduzierten Bauaufwand erfordert. Diese Aufgabe wird durch die kennzeichnenden Merkmale des ersten Anspruchs gelöst.The object of the present invention is to demonstrate a method according to the preamble of the first claim, which requires a construction work that is significantly reduced compared to the known method. This object is achieved by the characterizing features of the first claim.

Wird ein der Abgasanlage stromab des Abgas- Katalysators entnommener Abgas-Teilstrom stromauf des Abgas-Katalysatsors in die Abgastanlage eingeleitet, so ist mit diesem Teilstrom eine wirkungsvolle Kühlung des Abgases im Eintrittsbereich des Abgas-Katalysators erzielbar. Die für den Teilstrom erforderliche Rückführleitung kann dabei äußerst einfach ausgebildet sein: So ist - da nur ein Teilstrom geführt wird - lediglich ein geringer Platzbedarf erforderlich. Desweiteren kann auf aufwendige Kühlmaßnahmen verzichtet werden, da die über der Rückführstrecke erzielte Kühlwirkung für die erwünschte Temperaturabsenkung nach Einleitung des Teilstromes in die Abgasanlage ausreichend ist.If an exhaust gas partial flow removed from the exhaust gas system downstream of the exhaust gas catalytic converter is introduced into the exhaust gas system upstream of the exhaust gas catalytic converter, effective cooling of the exhaust gas in the inlet area of the exhaust gas catalytic converter can be achieved with this partial flow. The return line required for the partial flow can be made extremely simple: only a small space requirement is required since only one partial flow is carried. Furthermore, complex cooling measures can be dispensed with, since the cooling effect achieved over the return path is sufficient for the desired temperature reduction after the partial flow has been introduced into the exhaust system.

Zwar wird auch bei einer aus der JP-A 56 113 007 bekannten Abgasanlage einer Diesel-Brennkraftmaschine mit einem Rußfilter ein stromab des Rußfilters entnommener Abgas-Teilstrom zur Abgaskühlung herangezogen. Hierzu ist jedoch ein Wärmetauscher vorgesehen. Ferner wird der kühlende Abgasstrom dem Ansaugtrakt der Brennkraftmaschine zugeführt.In an exhaust system of a diesel engine with a soot filter known from JP-A 56 113 007, a partial exhaust gas stream taken downstream of the soot filter is also used for exhaust gas cooling. However, a heat exchanger is provided for this. Furthermore, the cooling exhaust gas flow is fed to the intake tract of the internal combustion engine.

Da bei vorliegender Erfindung der stromab des Abgaskatalysators Abgas-Teilstrom keinen freien Sauerstoff enthält, kann nach Einleitung des Teilstromes in die Abgasanlage bei eventuell im Abgasstrom vorhandenen unverbrannten Kohlenwasserstoffen keine den Katalysator schädigende Nachverbrennung stattfinden kann. Befindet sich in der Abgasanlage eine Sauerstoffsonde, mit Hilfe derer die Brennkraftmaschine zur optimalen Konvertierung des Abgases im Abgaskatalysator mit stöchiometrischem Gemisch betrieben wird, so wird deren Meßergebnis durch den zu Kühlzwecken zurückgeführten Abgas-Teilstrom ebenfalls nicht beeinflußt, da dieser Teilstrom, wenn er stromab des Abgaskatalysators entnommen wird, keinen freien Sauerstoff enthalten kann. Vorteilhafterweise kann der Teilstrom dem Abgas somit bereits stromauf der Sauerstoffsonde beigemengt werden, so daß auch die Sonde mit geringeren Abgas-Temperaturen beaufschlagt wird.Since, in the present invention, the exhaust gas partial flow downstream of the exhaust gas catalytic converter does not contain any free oxygen, after the partial flow has been introduced into the exhaust gas system, any unburned hydrocarbons which may be present in the exhaust gas stream cannot damage the catalyst. If there is an oxygen probe in the exhaust system, with the aid of which the internal combustion engine is operated with a stoichiometric mixture for optimal conversion of the exhaust gas in the exhaust gas catalytic converter, the measurement result thereof is also not influenced by the exhaust gas partial flow returned for cooling purposes, since this partial flow, if it is downstream of the Exhaust gas catalyst is removed, can not contain free oxygen. Advantageously, the partial stream can thus be added to the exhaust gas upstream of the oxygen probe, so that the probe is also subjected to lower exhaust gas temperatures.

Von Vorteil ist das erfindungsgemäße Verfahren desweiteren hinsichtlich der Konvertierung schädlicher Abgasbestandteile: Wegen der zweimaligen Durchströmung zumindest eines Abgasteilstromes durch den Abgaskatalysator ist eine tendenzielle Verringerung der nach dem Katalysator noch meßbaren Abgasemissionen feststellbar.The method according to the invention is also advantageous with regard to the conversion of harmful exhaust gas constituents: because the exhaust gas catalytic converter flows through at least one partial exhaust gas stream twice, a tendency to reduce the exhaust gas emissions that can still be measured after the catalytic converter can be determined.

Ist gemäß Anspruch 2 der Abgas-Teilstrom mengenmäßig steuerbar, so kann, beispielsweise in Abhängigkeit von der mittels eines Temperaturfühlers stromauf des Abgas-Katalysators ermittelten Abgastemperatur die für die erforderliche Abgaskühlung benötigte Teilstrommenge ermittelt und bereitgestellt werden.If the exhaust gas partial flow can be controlled in terms of quantity, the partial flow amount required for the required exhaust gas cooling can be determined and made available, for example depending on the exhaust gas temperature determined by means of a temperature sensor upstream of the exhaust gas catalytic converter.

Vorteilhafte Ausbildungen einer Abgasanlage zur Durchführung des erfindungsgemäßen Verfahrens sind in den Ansprüchen 3 bis 7 beschrieben. Demnach kann für den Abgas-Teilstrom eine einfache Rückführleitung ohne aufwendige Zusatzmaßnahmen vorgesehen sein, wenn in dieser Rückführleitung ein Rückschlagventil vorgesehen ist. Jenes Rückschlagventil hindert die Abgase daran, die Abgasanlage bereits stromauf des Abgas-Katalysators zu verlassen. Durch die von der periodischen Gaswechsel-Steuerung hervorgerufenen, in der Abgasanlage auftretenden Druckschwingungen wird jedoch bei Unterdruck der Weg für den stromab des Abgas-Katalysators entnommenen Teilstrom freigegeben, der Teilstrom wird stromauf des Abgas-Katalysators somit selbsttätig in die Abgasanlage gefördert. Zusätzlich bzw. alternativ zu jenem Rückschlagventil kann ein den Abgas-Teilstrom mengenmäßig steuerndes Drosselorgan beispielsweise in Form eines taktenden Magnetventiles vorgesehen sein.Advantageous embodiments of an exhaust system for carrying out the method according to the invention are described in claims 3 to 7. Accordingly, a simple return line without complex additional measures can be provided for the partial exhaust gas flow if a check valve is provided in this return line. The check valve prevents the exhaust gases from leaving the exhaust system upstream of the exhaust gas catalytic converter. However, due to the pressure fluctuations caused by the periodic gas exchange control and occurring in the exhaust system, the path for the partial flow taken downstream of the exhaust gas catalytic converter is released in the case of negative pressure, and the partial flow is thus automatically conveyed upstream of the exhaust gas catalytic converter into the exhaust system. In addition or as an alternative to that non-return valve, a throttle element which controls the quantity of the partial exhaust gas flow can be added for example in the form of a clocking solenoid valve.

Ebenso kann das in der Rückführleitung vorgesehene, allgemein als Regelorgan bezeichnete und die Strömungsverhältnisse in der Rückführleitung beeinflussende Element als Fördereinrichtung für den rückgeführten Abgas-Teilstrom ausgebildet sein. Derartige Fördereinrichtungen, beispielsweise Pumpen oder kleine Strömungsverdichter fördern in Betriebspunkten der Brennkraftmaschine, in denen der stromab des Abgaskatalysators herrschende Abgasdruck nicht ausreichend ist, den gewünschten Abgas-Teilstrom stromauf des Abgaskatalysators in die Abgasanlage zurück. Bei entsprechender Ausgestaltung kann dabei die Fördervorrichtung die Funktion des Rückschlagventiles sowie des Drosselorganes übernehmen. Stets empfiehlt es sich dabei, gemäß Anspruch 7 die Mündung der Rückführleitung in dem an der Brennkraftmaschine angeflanschten Abgaskrümmer vorzusehen, da hiermit nicht nur eine hohe Abkühlrate erzielbar ist, sondern dort auch der höchstmögliche Förder-Unterdruck auftritt. Dies ist vorteilhaft in Anwendungsfällen, in denen die Rückführung aufgrund der in der Abgasanlage auftretenden Druckschwingungen erfolgt.Likewise, the element provided in the return line, generally referred to as a control element and influencing the flow conditions in the return line, can be designed as a conveying device for the recirculated exhaust gas partial flow. Conveying devices of this type, for example pumps or small flow compressors, convey the desired partial exhaust gas stream upstream of the exhaust gas catalytic converter back into the exhaust system at operating points of the internal combustion engine in which the exhaust gas pressure downstream of the exhaust gas catalytic converter is not sufficient. With a corresponding design, the conveying device can take over the function of the check valve and of the throttle element. It is always advisable to provide the mouth of the return line in the exhaust manifold flanged to the internal combustion engine, since not only can a high cooling rate be achieved with this, but also the highest possible delivery vacuum occurs there. This is advantageous in applications in which the return takes place due to the pressure vibrations occurring in the exhaust system.

Im folgenden wird die vorliegende Erfindung anhand eines nur prinzipiell dargestellten, bevorzugten Ausführungsbeispieles näher beschrieben.The present invention is described in more detail below on the basis of a preferred exemplary embodiment which is only shown in principle.

An eine Brennkraftmaschine 1 ist eine in ihrer Gesamtheit mit 2 bezeichnete Abgasanlage angeflanscht. Diese setzt sich zusammen aus zwei Krümmern 3a, 3b, einem sich daran anschließenden Abgasrohr 4, in welchem ein Sauerstoffühler 5 angeordnet ist, und welches in den Abgasaktalysator 6 mündet. An diesen schließt sich über eine Rohrverbindung ein Nachschalldämpfer 7 an.An exhaust gas system, designated in its entirety by 2, is flanged to an internal combustion engine 1. This consists of two elbows 3a, 3b, an adjoining exhaust pipe 4, in which an oxygen sensor 5 is arranged, and which opens into the exhaust gas analyzer 6. This is followed by a rear silencer 7 via a pipe connection.

Erfindungsgemäß zweigen von der Abgasanlage 2 zwischen dem Katalysator 6 sowie dem Nachschalldämpfer 7 zwei Rückführleitungen 8a, 8b ab, welche in die Krümmer 3a, 3b münden. In der Rückführleitung 8a ist ein Rückschlagventil 9 sowie ein Magnetventil 10 angeordnet. Das Rückschlagventil 9 verhindert dabei, daß Abgas über die Rückführleitung 8 entgegen der Pfeilrichtung 11 direkt von dem Krümmer 3a zum Nachschalldämpfer 7 gelangen kann. Eine andere Ausbildung ist in der Abgasleitung 8b realisiert, welche eine Fördervorrichtung 12 für den rückzuführenden Abgas-Teilstrom enthält.According to the invention, two return lines 8a, 8b branch off from the exhaust system 2 between the catalytic converter 6 and the rear muffler 7 and open into the manifolds 3a, 3b. A check valve 9 and a solenoid valve 10 are arranged in the return line 8a. The check valve 9 prevents exhaust gas from passing through the return line 8 against the arrow direction 11 directly from the manifold 3a to the rear silencer 7. Another embodiment is implemented in the exhaust line 8b, which contains a conveyor device 12 for the exhaust gas partial flow to be recycled.

Ist das Magnetventil 10 offen, so wird aufgrund des in den Krümmern 3 periodisch auftretenden Unterdruckes unter Zuhilfenahme des vor dem Nachschalldämpfer 7 vorhandenen geringen Abgasgegendruckes Überdruck) ein Teilstrom von Abgas, welches den Katalysator 6 bereits passiert hatte, über die Rückführleitung 8a in Pfeilrichtung 11 in den Krümmer 3a eingeleitet. In ähnlicher Weise fördert die Fördervorrichtung 12 steuerbar einen Abgas-Teilstrom gemäß Pfeilrichtung 11 zum Krümmer 3b.If the solenoid valve 10 is open, a partial flow of exhaust gas, which had already passed the catalytic converter 6, becomes via the return line 8a in the direction of the arrow 11 in due to the negative pressure which occurs periodically in the manifolds 3 with the aid of the low exhaust gas back pressure (upstream of the rear silencer 7) the manifold 3a initiated. In a similar manner, the conveying device 12 controllably conveys a partial exhaust gas flow in the direction of the arrow 11 to the manifold 3b.

Jene Teilströme kühlen sich dabei insbesondere in den Rückführleitungen 8 soweit ab, daß der von der Brennkraftmaschine 1 abgegebene Abgasstrom durch Beimischung dieser Teilströme mit seiner Temperatur auf ein für den Katalysator 6 verträgliches Niveau abgesenkt wird. Durch entsprechende Ansteuerung des Magnetventiles 10 bzw. der Fördervorrichtung 12 können dabei die über die Rückführleitungen 8 geführten Teilströme mengenmäßig derart gesteuert werden, daß das Temperaturniveau nach Zusammenführung in den Krümmern 3 bzw. im Abgasrohr 4 einen gewünschten Wert erreicht. Ermittelt werden kann dieses Temperaturniveau beispielsweise durch einen nicht gezeigten Temperaturfühler, welcher über eine ebenfalls nicht gezeigte Steuereinheit auf das Magnetventil 10 bzw. die Fördervorrichtung 12 eingreift.Those partial flows cool down in particular in the return lines 8 to such an extent that the exhaust gas flow emitted by the internal combustion engine 1 is reduced to a level compatible with the catalytic converter 6 by admixing these partial flows with its temperature. By appropriate activation of the solenoid valve 10 or the conveyor device 12, the partial flows guided via the return lines 8 can be controlled in such a quantity that the temperature level reaches a desired value after being brought together in the elbows 3 or in the exhaust pipe 4. This temperature level can be determined, for example, by a temperature sensor, not shown, which engages the solenoid valve 10 or the conveying device 12 via a control unit, also not shown.

Da der nach dem Katalysator 6 entnommene Abgasteilstrom keinen freien Sauerstoff enthält, wird durch die Beimengung jenes Teilstromes in den Krümmern 3 die Regelung des der Brennkraftmaschine zugeführten stöchiometrischen Gemisches durch den Sauerstoffühler 5 nicht weiter beeinflußt. Das gezeigte Ausführungsbeispiel stellt lediglich eine mögliche Abgasanlage zur Durchführung des. erfindungsgemäßen Verfahrens zur Beeinflussung der Temperatur von Abgasen dar; Abwandlungen hiervon sind ohne weiteres denkbar.Since the partial exhaust gas stream taken after the catalyst 6 contains no free oxygen, the addition of that partial stream in the manifolds 3 does not further influence the regulation of the stoichiometric mixture fed to the internal combustion engine by the oxygen sensor 5. The exemplary embodiment shown merely represents a possible exhaust system for carrying out the method according to the invention for influencing the temperature of exhaust gases; Modifications from this are easily conceivable.

Claims (7)

1. A method of influencing the temperature of exhaust gases in the inlet region of an exhaust-gas catalyst (6) disposed in an exhaust-gas system (E) of a quantitatively control led internal combustion engine (1), characterised in that a partial stream of exhaust gas taken from the exhaustgas system (E) downstream of the catalyst (6) is introduced into the exhaust-gas system (2) upstream of the catalyst (6).
2. A method according to claim 1, characterised in that the partial stream of exhaust gas is control in size.
3. An exhaust-gas system in a quantitatively-control led internal combustion engine comprising an exhaust-gas catalyst for working the method according to claim 1 or 2, characterised in that a pipe (8) for returning a partial stream of exhaust gas and containing a control means branches off the exhaust- gas system (2) downstream of the catalyst (6) and opens into the exhaust-gas system (2) upstream of the catalyst (6).
4. An exhaust-gas system according to claim 3, characterised in that the control means is a non-return valve (9).
5. An exhaust-gas system according to claim 3 or 4, characterised in that the control means i5 a throttle means (solenoid valve 10) which controls the flow rate in dependence on the exhaust-gas temperature in the inlet region of the catalyst (6).
6. An exhaust-gas system according to any of claims 3 to 5, characterised in that the control means is a device (12) for delivering the partial stream of exhaust gas to be returned.
7. An exhaust-gas system according to any of claims 3 to 6, characterised in that the return pipe (8) opens into the exhaust-gas pipe bends (3a, 3b).
EP88116975A 1987-10-30 1988-10-13 Method for influencing the exhaust gas temperature, and exhaust apparatus to carry out the method Expired - Lifetime EP0313922B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3736844 1987-10-30
DE19873736844 DE3736844A1 (en) 1987-10-30 1987-10-30 METHOD FOR INFLUENCING THE TEMPERATURE OF EXHAUST GAS AND EXHAUST SYSTEM FOR CARRYING OUT THE METHOD

Publications (2)

Publication Number Publication Date
EP0313922A1 EP0313922A1 (en) 1989-05-03
EP0313922B1 true EP0313922B1 (en) 1990-11-28

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EP88116975A Expired - Lifetime EP0313922B1 (en) 1987-10-30 1988-10-13 Method for influencing the exhaust gas temperature, and exhaust apparatus to carry out the method

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EP (1) EP0313922B1 (en)
DE (2) DE3736844A1 (en)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2655376B1 (en) * 1989-12-06 1992-04-03 Peugeot DEVICE FOR THE EXHAUST AND ANTI-POLLUTION TREATMENT OF EXHAUST GAS FROM AN ENGINE AND CORRESPONDING METHOD.
DE4021495A1 (en) * 1990-07-05 1992-01-09 Schwaebische Huettenwerke Gmbh EXHAUST FILTER
DE4127633A1 (en) * 1991-08-21 1993-02-25 Bayerische Motoren Werke Ag Multicylinder IC engine with catalytic converter - arrangement of one exhaust pipe inside another upstream of converter to conserve heat
DE19744191C2 (en) * 1996-09-30 2000-08-24 Leistritz Abgastech Catalytic converter
DE10051358A1 (en) * 2000-10-17 2002-06-20 Bosch Gmbh Robert Exhaust gas cleaning system with a catalytic converter arrangement and method for cleaning exhaust gases
JP4394868B2 (en) * 2002-07-30 2010-01-06 日産自動車株式会社 Engine exhaust system
EP2982842B1 (en) * 2014-08-07 2018-03-14 S.T.C. S.r.l. System for reducing harmful emissions of an internal combustion engine

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS56113007A (en) * 1980-02-08 1981-09-05 Toyota Motor Corp Exhaust gas purifier for internal combustion engine

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3645098A (en) * 1970-09-28 1972-02-29 Gen Motors Corp Exhaust emission control
AU446214B2 (en) * 1971-03-12 1974-02-22 General Motors Corporation Internal combustion engine exhaust gas emission. control apparatus
GB1349051A (en) * 1971-07-19 1974-03-27 Ford Motor Co Internal combustion engine with an exhaust gas storage device in the exhaust system
DE2237781A1 (en) * 1972-08-01 1974-02-14 Volkswagenwerk Ag COMBUSTION ENGINE, IN PARTICULAR FOR MOTOR VEHICLES, WITH A DEVICE FOR THE REMOVAL OF HARMFUL EXHAUST COMPONENTS
US3776207A (en) * 1972-11-03 1973-12-04 Ford Motor Co Engine constant rate exhaust gas recirculation system
DE2303773A1 (en) * 1973-01-26 1974-08-01 Volkswagenwerk Ag ARRANGEMENT FOR EXHAUST GAS EXHAUST
BE836913A (en) * 1975-12-22 1976-04-16 SYSTEM FOR THE RECONVERTION OF THE EXHAUST GASES IN HYDROCARBONS
JPS53126422A (en) * 1977-04-11 1978-11-04 Nippon Soken Inc Exhaust gas purifying system in multi-cylinder internal combustion engine
DE3406968A1 (en) * 1984-02-25 1985-03-28 Daimler-Benz Ag, 7000 Stuttgart Method for producing an optimum exhaust gas inlet temperature for the exhaust catalytic converter of internal-combustion engines
DE3618762A1 (en) * 1985-06-13 1986-12-18 Volkswagen AG, 3180 Wolfsburg Exhaust pipe arrangement

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS56113007A (en) * 1980-02-08 1981-09-05 Toyota Motor Corp Exhaust gas purifier for internal combustion engine

Also Published As

Publication number Publication date
DE3736844A1 (en) 1989-05-11
DE3861184D1 (en) 1991-01-10
EP0313922A1 (en) 1989-05-03
DE3736844C2 (en) 1991-06-06

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