A regeneration control device for an exhaust purification device includes a regeneration controller that executes regeneration control in which particulate matters trapped by a filter are removed by combustion, and a post-injection controller that during the regeneration control, executes control in which a time period of a post-injection of fuel executed subsequently to a main injection of fuel is advanced such that a supercharging pressure of a turbosupercharger becomes higher than a supercharging pressure during steady operation.

This NOx reduction control method is for an exhaust gas aftertreatment device having an oxidation catalyst and an LNT catalyst which are disposed in an exhaust pipe and repeating an adsorption or occlusion of NOx which is executed when an air-fuel ratio is in a lean state and a reduction of NOx which is executed when the air-fuel ratio is in a rich state, the method including executing a post-injection or an exhaust pipe injection and causing HC to be adsorbed in the oxidation catalyst when an exhaust gas temperature is low, and causing the HC which is adsorbed in the oxidation catalyst to be desorbed and reducing an adsorbed NOx in the LNT catalyst by raising the exhaust gas temperature during the rich state.

This disclosure relates generally to emissions treatment devices including aftertreatment devices that may be utilized with internal combustion engines and, more particularly, to methods and systems for controlling in-cylinder dosing (ICD) and preventing fuel to oil dilution. A method of operating an engine converting an amount of heat needed for regenerating an aftertreatment device into a cam-stroke fueling strategy. The method further includes determining a number of the engine's cylinders to be active cylinders for introducing dosing fuel and calculating a total dosing fuel apportionment of the dosing fuel for each of the active cylinders based on the cam-stroke fueling strategy. A number of dosing shots per injector for each of the active cylinders can be calculated based on the total dosing fuel apportionment and an amount of dosing fuel is apportioned for each dosing shot according to the cam-stroke fueling strategy.

An exhaust emission control system of an engine including a NO.sub.x catalyst for storing NO.sub.x within exhaust gas when an air-fuel ratio thereof is lean, and reducing the NO.sub.x when the air-fuel ratio is approximately stoichiometric or rich, the NO.sub.x catalyst also functioning as an oxidation catalyst for oxidizing HC, is provided. The system includes a SCR catalyst for purifying NO.sub.x by causing a reaction with NH.sub.3, a urea injector, and a processor configured to execute a fuel injection controlling module, and a NO.sub.x reduction controlling module for performing a NO.sub.x reduction control to enrich the air-fuel ratio to a target ratio. When the urea injection is abnormal, the NO.sub.x reduction controlling module performs an NH.sub.3-supplied NO.sub.x reduction control in which the NO.sub.x catalyst supplies NH.sub.3 to the SCR catalyst, by performing the NO.sub.x reduction control, a lean air-fuel ratio operation control, and then the NO.sub.x reduction control again.

An exhaust emission control device for an engine is provided with a first purifying catalyst including an HC adsorbent that adsorbs HC at a low temperature and releases HC at a high temperature and a diesel oxidation catalyst capable of oxidizing HC, a second purifying catalyst including a NOx catalyst capable of storing NOx contained in exhaust, a NOx catalyst regenerator that regenerates the NOx catalyst while raising the temperature of the NOx catalyst, and HC controller that decides whether the amount of adsorbed HC that is HC adsorbed by the HC adsorbent is equal to or more than a preset reference amount and, when the amount of adsorbed HC is decided to be equal to or more than the reference amount, raises the temperature of the first purifying catalyst.

An exhaust gas purification system comprises a first fuel supply unit to supply fuel to exhaust gas flowing in an exhaust passage by a supply valve arranged in the exhaust passage, and a second fuel supply unit to supply fuel to exhaust gas by adjusting a fuel injection condition, wherein in a temperature raising stage of the NOx SCR catalyst associated with the exhaust gas temperature raising processing, first control is performed in which fuel is supplied by the first fuel supply unit, and in a temperature holding stage of the NOx SCR catalyst associated with the exhaust gas temperature raising processing, at least second control is performed in which the ratio of an amount of fuel supply by the second fuel supply unit with respect to an amount of fuel supply by the first fuel supply unit becomes higher in comparison with that when performing the first control.

A system includes an exhaust aftertreatment system including a particulate filter and a controller. The controller is configured to: receive information comprising a temperature regarding a filter of the aftertreatment system; and responsive to determining that the temperature regarding the filter is below a temperature threshold, command the engine to operate according to a first firing fraction. The first firing fraction may define a number of active cylinders of the engine relative to a total number of cylinders of the engine, and correspond to a predetermined temperature value of the filter.

A diesel engine system includes a diesel engine, an exhaust line, a particulate filter interposed in the exhaust line and an electronic control unit for controlling fuel injectors associated with cylinders of the engine. When an accumulated particulate mass in said filter reaches a predetermined threshold, a filter regeneration mode is activated, including activating post-injections of fuel by controlling said injectors, to determine a start of an automatic filter regeneration step, which is caused by an increase in temperature of exhaust gases fed to the filter. The temperature increase is sufficient to burn particulate in the filter. The post-injections of fuel are deactivated whenever a critical condition occurs for at least a first period of time, the critical condition being one in which a temperature value upstream of the filter exceeds a first threshold value. In this case, the regeneration mode is resumed following disappearance of the critical condition.

An exhaust system for treating an exhaust gas from an internal combustion engine is disclosed. The system comprises a modified lean NO.sub.x trap (LNT), a urea injection system, and an ammonia-selective catalytic reduction (NH.sub.3-SCR) catalyst. The modified LNT comprises platinum, palladium, barium, and a ceria-containing material, and has a platinum:palladium molar ratio of at least 3:1. The modified LNT stores NO.sub.x at temperatures below about 200? C. and releases the stored NO.sub.x at temperatures above about 200? C. The urea injection system injects urea at temperatures above about 180? C.

An intake stroke injection and a compression stroke injection are performed during catalyst warm-up control (upper section in FIG. 7). During the catalyst warm-up control, a discharge period at an electrode portion is set on a retard side of compression top dead center, and an expansion stroke injection is performed during the discharge period. However, when a distance between a spray contour surface and the electrode portion increases, an additional injection (first injection) is performed in advance of the expansion stroke injection (second injection) (lower section in FIG. 7). The additional injection is performed at a timing that is on the retard side of compression top dead center and is on an advance side relative to a start timing of the discharge at the electrode portion.