Abstract:
In an exhaust purification system of an internal combustion engine, comprising a NOX catalyst device, which can satisfactorily store NOX in the exhaust gas when the concentration of oxygen in the exhaust gas is high and can release the stored NOX and purify the released NOX to N2 by reducing materials in the exhaust gas when the concentration of oxygen is decreased as a regeneration treatment, the regeneration treatment is carried out to change a combustion air-fuel ratio from a lean air-fuel ratio to a set rich air-fuel ratio, and N2O reducing material is supplied to the NOX catalyst device during at least one of a first period set within a period in which an air-fuel ratio in the exhaust gas within said NOX catalyst device changes from the lean air-fuel ratio to the set rich air-fuel ratio when the regeneration treatment is started and a second period set within a period after an air-fuel ratio in the exhaust gas within the NOX catalyst device becomes the stoichiometric air-fuel ratio when the regeneration treatment is finished.
Abstract:
An exhaust as catalytic converter is laden with oxygen until it is saturated at least upstream of an exhaust as probe. A predefined first rich air/fuel ration is set in a combustion chamber of a cylinder. A first oxygen storage capacity value is determined as a function of the measurement signal of an exhaust as probe and the predefined first rich air/fuel ratio. The exhaust as catalytic converter is laden with oxygen until it is saturated. A predefined second rich air/fuel ration is set in the combustion chamber of the cylinder. A second oxygen storage capacity value is determined as a function of the measurement signal of the exhaust as probe and the predefined second rich air/fuel ration. A corrected oxygen storage capacity value is determined as a function of the first and second oxygen storage capacity values.
Abstract:
Various embodiments of an apparatus, system, and method are disclosed for reducing NOx emissions on an SCR catalyst. For example, according to one representative embodiment, an apparatus for reducing NOx emissions in an engine exhaust includes a NOx reduction target module that is configured to determine a NOx reduction requirement that includes an amount of NOx in the exhaust gas stream to be reduced on a selective catalytic reduction (SCR) catalyst. The apparatus also includes an ammonia target module that is configured to determine an ammonia addition requirement that includes an amount of ammonia added to the exhaust gas stream to achieve the NOx reduction requirement. The apparatus also includes a reductant target module that is configured to determine a reductant injection requirement that includes an amount of reductant added to the exhaust gas stream to achieve the ammonia addition requirement. The apparatus further includes a reductant limiting module that is configured to determine whether at least one reductant limiting condition is met and to limit the amount of reductant added in response to the at least one reductant limiting condition if the at least one reductant limiting condition has been met.
Abstract:
An exhaust gas catalytic converter is laden with oxygen until it is saturated at least upstream of an exhaust gas probe. A predefined first rich air/fuel ration is set in a combustion chamber of a cylinder. A first oxygen storage capacity value is determined as a function of the measurement signal of an exhaust gas probe and the predefined first rich air/fuel ratio. The exhaust gas catalytic converter is laden with oxygen until it is saturated. A predefined second rich air/fuel ration is set in the combustion chamber of the cylinder. A second oxygen storage capacity value is determined as a function of the measurement signal of the exhaust gas probe and the predefined second rich air/fuel ration. A corrected oxygen storage capacity value is determined as a function of the first and second oxygen storage capacity values.
Abstract:
When the first fuel injection is performed after reversion from the fuel cut, the fuel pulse width Ka·INJ.PW is set so that a fuel supply amount is greatly increased in relation to an intake air amount, and the ignition timing is set to the first retarded ignition timing θa. When the second and subsequent fuel injections are performed, the fuel pulse width Kb·INJ.PW that is smaller in increase width of fuel is set, and the ignition timing is set to the second retarded ignition timing θb that has a retardation amount smaller than that of the first retarded ignition timing θa.
Abstract:
In a method for the control of the supplied air/fuel ratio of an internal combustion engine (1) with a catalytic converter (5) which is located in the exhaust gas line (2) with an integrated oxygen reservoir (6), it is suggested that the air/fuel ratio be controlled as a function of at least one parameter of the internal combustion engine (1), at least one parameter of the catalytic converter (5), and/or as a function of the type and amount of the exhaust gas emissions currently occurring, in order to optimize the speed for adjustment of the admission or discharge of oxygen in the oxygen reservoir (6) contained in the catalytic converter (5) for favorable conversion of the exhaust gas emissions during transient operation of the internal combustion engine (1) and after deviations from the air/fuel ratio λ=1. As claimed in the invention, a “disturbance” of the exhaust gas composition which occurs during transient operation of the internal combustion engine (1) is corrected with a speed which takes into account both the current conversion demand by the catalytic converter (5) and also the current conversion performance of the catalytic converter (5) and thus makes possible improved overall exhaust gas conversion.
Abstract:
The invention relates to a process for heating a catalytic converter, a nitric oxide storage catalytic converter and/or particle filter in particular mounted in an exhaust system of a diesel internal combustion engine of a vehicle, to a desulfation and/or decarbonization temperature, a process in which the catalytic converter is heated to a desulfation and/or decarbonization temperature at the beginning of the desulfation and/or decarbonization phase as regeneration phase. A rich exhaust gas flow is delivered periodically to the catalytic converter for the purpose of direct heating of this catalytic converter to a regeneration temperature, in such a way that the unburnt exhaust gas components, hydrocarbons and carbon monoxides in particular, react to the oxygen stored in the catalytic converter and the thermal energy released in the process heats the catalytic converter to a regeneration temperature. A catalytic converter is also proposed in which the oxygen storage component is unevenly distributed over the catalytic converter in the direction of flow of the exhaust gas, in such a way that, as viewed in the direction of flow, the highest oxygen storage capacity is present at the exhaust gas inlet of the catalytic converter as viewed in the direction of flow.
Abstract:
Il est proposé un boîtier (10) pour un composant (9) sensible à l'ammoniac dans un système de dépollution par réduction catalytique sélective. Ce boîtier comprend d'une part une paroi (17) et d'autre part un piège (12) configuré pour capter de l'ammoniac gazeux émanant de la paroi ou qui, s'il n'était pas piégé, émanerait de la paroi.
Abstract:
排気ガス中の酸素濃度が高い時には排気ガス中のNO X を良好に保持し、再生処理として、排気ガス中 の酸素濃度を低下させれば、保持したNO X を離脱し、こうして離脱させたNO X を排気ガス中の還元物 質によりN 2 へ還元浄化することができるNO X 触媒装置を具備する内燃機関の排気浄化装置において、 再生処理は燃焼空燃比をリーン空燃比ALから設定リッチ空燃比ARへ変化させることにより実施され 、再生処理を開始するためにNO X 触媒装置内の排気ガスの空燃比がリーン空燃比から設定リッチ空燃比 となるまでの間における第一設定期間(t2-t3)、及び、再生処理を終了するためにNO X 触媒装置 内の排気ガスの空燃比が理論空燃比ASとなった以降における第二設定期間(t6-t7)の少なくと も一方において、NO X 触媒装置へN 2 O還元剤を供給する。
Abstract:
For example, according to one representative embodiment, an apparatus (130) for reducing NOx emissions in an engine exhaust includes a NOx reduction target module (300) configured to determine a NOx reduction requirement (304). The apparatus also includes a tailpipe NOx module (397) configured to determine a sensed amount of NOx exiting the engine system (10) and a signal correction algorithm module (351) configured to determine a corrected amount of NOx (399) exiting the engine system based at least partially on the sensed amount of NOx exiting the engine system. The apparatus also includes a feedback ammonia target module (344) configured to determine a feedback ammonia addition requirement (348). The feedback ammonia addition requirement includes an amount of ammonia added to the exhaust gas stream to achieve the NOx reduction requirement in response to the corrected amount of NOx exiting the engine system. The apparatus also includes a reductant target module (330) that is configured to determine a reductant injection requirement (332).