A converter containing a NOx absorbing and reducing catalyst is disposed in the exhaust passage of an internal combustion engine. The upstream half portion (portion of the inlet side) of the substrate of the NOx absorbing and reducing catalyst in the converter carries the oxygen storage component that absorbs oxygen in the exhaust gas when the air-fuel ratio of the exhaust gas is lean and releases the absorbed oxygen when the air-fuel ratio of the exhaust gas flowing in is rich in addition to carrying the NOx absorbing and reducing catalyst. After NOx is absorbed by the NOx absorbing and reducing catalyst as a result of operating the engine at a lean air-fuel ratio, the engine is operated at a rich air-fuel ratio, so that NOx is released from the NOx absorbing and reducing catalyst and is purified by reduction. Here, oxygen is released from the oxygen storage component carried by the upstream half portion of the substrate and is reacted with the H 2 and CO components in the exhaust gas, so that the temperature of the NOx absorbing and reducing catalyst is raised within short periods of time due to the heat of reaction. Therefore, the catalyst exhibits increased activity and the NOx absorbing and reducing catalyst exhibits improved NOx purification capability.

Exhaust gas purification device for an internal combustion engine

An exhaust gas aftertreatment installment and associated exhaust gas aftertreatment method utilizes a nitrogen oxide storage catalytic converter and an SCR catalytic converter. A particulate filter is provided upstream of the nitrogen oxide storage catalytic converter or between the latter and the SCR catalytic converter or downstream of the SCR catalytic converter. The time of regeneration operating phases of the nitrogen oxide storage catalytic converter can be determined as a function of the nitrogen oxide content of the exhaust gas downstream of the nitrogen oxide storage catalytic converter or of the SCR catalytic converter and/or as a function of the ammonia loading of the latter. Moreover, a desired ammonia generation quantity can be determined for a respective regeneration operating phase. The installation and method are adopted for use for motor vehicle internal combustion engines and other engines which are operated predominantly in lean-burn mode.

Exhaust Gas Aftertreatment Installation and Method

One aspect of the invention relates an exhaust treatment system having an SCR reactor following a NOx adsorber. Syn gas is used to regenerate the NOx adsorber. Another aspect relates to an LNT/SCR provided with an ammonia source separate from the LNT. A further aspect relates to a system comprising first and second LNTs and one or more SCRs downstream of the LNTs. A still further aspect relates to a device comprising first and second NOx adsorbers contained in a single housing. Another aspect relates to coating a surface of a moving part in an exhaust system with an oxidation catalyst to mitigate fouling. Additional aspects of the invention relate to strategies for controlling one or more of the time to initiate a regeneration cycle, the time to terminate a regeneration cycle, and the reductant injection rate during regeneration of LNT/SCR exhaust treatment systems.

Hybrid catalyst system for exhaust emissions reduction

A first cylinder and a second cylinder are provided. A first exhaust pipe is connected to the first cylinder and a second exhaust pipe is connected to the second cylinder. A communicating pipe connects together an intermediate portion of the first exhaust pipe with an intermediate portion of the second exhaust pipe. An exhaust gas control catalyst is arranged in the second exhaust pipe downstream of the portion to which the communicating pipe is connected. Exhaust gas amount reducing devices are provided which reduce the amount of exhaust gas that flows from the first exhaust pipe into the second exhaust pipe through the communicating pipe during execution of rich/lean burn control which performs combustion with an air-fuel ratio of an air-fuel mixture that is richer than the stoichiometric air-fuel ratio in one of the first cylinder and second cylinder and performs combustion with an air-fuel ratio of an air-fuel mixture that is leaner than the stoichiometric air-fuel ratio in the other cylinder.

Exhaust Gas Control Apparatus for Internal Combustion Engine

An internal combustion engine comprises an intake tract in which a throttle valve is disposed. The engine also comprises a camshaft which acts on gas inlet valves associated with respective cylinders. A phase-adjustment device is used to adjust a phase between the camshaft and a crankshaft. A desired air mass flow in a combustion chamber of the cylinder is determined depending on a charge requirement requested by the driver. The desired air mass flow is adjusted by varying the phase between the camshaft and the crankshaft if the desired air mass flow can be adjusted by varying the phase while substantially maintaining an actual pressure difference upstream and downstream of the throttle valve. Otherwise, the desired air mass flow is adjusted by varying the opening angle of the throttle valve.

Method and device for controlling an internal combustion engine

Die Erfindung betrifft eine Vorrichtung und ein Verfahren zur Steuerung einer Abgasruckfuhrrate (AGR-Rate) einer Abgasruckfuhreinrichtung (AGR-Einrichtung) fur Verbrennungskraftmaschinen wahrend eines Magerbetriebs, wobei einem in einer Abgasruckfuhrleitung angeordneten Stellmittel der AGR-Einrichtung eine Stellgrosse vorgegeben wird, die eine Einstellung oder Aufrechterhaltung einer gewunschten Abgasruckfuhrrate bewirkt. Es ist vorgesehen, dass eine Abweichung einer berechneten Schadstoffemission von einer durch einen Schadstoff-Sensor (18) im Abgasstrang (14) der Verbrennungskraftmaschine (10) gemessenen Schadstoffemission ermittelt und in Abhangigkeit von einer Hohe der Abweichung ein Korrekturwert fur die Stellgrosse des Stellmittels (28) der AGR-Einrichtung (12) bestimmt wird.

Vorrichtung und Verfahren zur Steuerung einer Abgasrückführrate einer Abgasrückführeinrichtung für Verbrennungskraftmaschinen während eines Magerbetriebs

Exhaust Gas Aftertreatment of Volkswagen FSI Fuel Stratified Injection Engines

In a method for adjusting the fuel/air ratio in an internal combustion engine ( 1 ) comprising a converter ( 2 ) which is associated therewith, a composition of waste gas in the waste gas wing ( 3, 8 ) of the internal combustion engine ( 1 ) is detected by means of sensors ( 4, 5 ) and output signals from at least one of the sensors ( 4, 5 ) are used for producing a control signal in order to influence the fuel/air ratio. The fuel/air ratio is switched back and forth between a lean operating state with surplus oxygen and a rich operating state with an oxygen deficit by means of a characteristic line of the control signal. The characteristic line of the control signal is adapted to a current converter state. A characteristic curve contour of the characteristic line is adjusted according to the addition and/or desorption of an oxidation agent in the converter ( 2 ). The invention also relates to a device for carrying out said method.

Method and device for adjustment of a fuel/air ratio for an internal combustion engine

The invention relates to a cooling circuit (1) for an internal combustion engine (2) having exhaust gas recirculation. The internal combustion engine (2) has a coolant inlet (3) and a coolant outlet (4). The cooling circuit (1) further comprises a main cooler (5) having a cooler inlet (6) and a cooler outlet (7), an EGR cooler (8) having an EGR cooler inlet (9) for coolant, and an EGR outlet (10) for coolant, and a main control device (11) disposed upstream of the internal combustion engine (2) in the flow direction of the coolant. In order that the EGR cooler (8) can provide the performance required, and that maximum operating reliability of the cooling circuit (1) and the modules provided in the cooling circuit (1) is possible, according to the invention the cooling circuit (1) has an auxiliary control device (12) disposed downstream of the exhaust gas recirculation cooler (8) in the flow direction of the coolant, and/or an exhaust gas recirculation control device (13) disposed upstream of the exhaust gas recirculation cooler (8) in the flow direction of the coolant. The invention further relates to a method for operating an internal combustion engine (2) having such a cooling circuit (1).

Cooling circuit for an internal combustion engine having exhaust gas recirculation and method for operating an internal combustion engine having such a cooling circuit

An engine configuration includes an internal combustion engine with a plurality of cylinders, at least one turbocharger and a first and a second exhaust gas tract. A turbine of the at least one turbocharger is associated with the first exhaust gas tract. Increased torque and increased power can be achieved when a bypass exhaust gas line emerging from at least one cylinder, which is associated with the first exhaust gas tract, is connected to the first exhaust gas tract such that it bypasses the at least one turbocharger.

Ekkehard Pott

Papers

Vorrichtung und Verfahren zur Steuerung einer Abgasrückführrate einer Abgasrückführeinrichtung für Verbrennungskraftmaschinen während eines Magerbetriebs

Exhaust Gas Aftertreatment of Volkswagen FSI Fuel Stratified Injection Engines

Method and device for adjustment of a fuel/air ratio for an internal combustion engine

Cooling circuit for an internal combustion engine having exhaust gas recirculation and method for operating an internal combustion engine having such a cooling circuit

Engine configuration including an internal combustion engine