An exhaust gas purification system comprises an exhaust gas purification device which is arranged in an exhaust gas route of an engine, renewing devices for burning and removing a particulate matter within the exhaust gas purification device, renewal advance notifying means which is actuated in the case that a clogged state of the exhaust gas purification device becomes equal to or more than a prescribed level, and renewal informing means which informs of a fact that the renewing devices are under operation. The renewal advance notifying means is actuated before actuating the renewing devices.

A controller and a control method for internal combustion engine, and a memory medium are provided. A port injection ratio is changed according to an engine operating state of the internal combustion engine. The port injection ratio is a ratio of a port injection amount that is an amount of fuel injected by port injection valves to an amount of fuel supplied to cylinders from the port injection valves and direct injection valves. An injection reducing process causes a fuel injection amount in a reduced-injection cylinder to be smaller than a fuel injection amount in other cylinders. An increase limiting process limits increases in an adhered fuel amount in intake ports by regulating the port injection ratio during execution of the injection reducing process.

Provided is a pre-chamber type diesel engine wherein the fuel system is not complicated, regardless of whether a regeneration function is provided. An injector is employed, which is able to inject fuel at a given timing by means of an electrical signal from a controller, and when a prescribed amount of particles have been trapped in a particle collection filter the injector carries out an additional fuel injection during the expansion stroke of a piston.

The occurrence of the misfire having a level at which exhaust purifying function of a catalyst is impaired (OT-level misfire) is detected. Upon the detection of the OT-level misfire, basic OT risk from the misfire is multiplied by a correction coefficient corresponding to the accumulated PM amount on the catalyst. The basic OT risk from the misfire is a basic value of OT risk from the misfire which is set based on the operating condition of the engine. The correction coefficient is set to a smaller value as the accumulated PM amount increases. Therefore, the OT risk from the misfire after the multiplication decreases as the accumulated PM amount increases. When a predetermined judgement condition with the OT risk from the misfire is established, it is judged that the misfire having the level occurs.

A method of calibrating a soot load estimating function for a diesel particulate filter uses radio frequency attenuation measurement and temperature measurements. The method comprises identifying a minimum mean attenuation value associated with a standard deviation that exceeds a standard deviation threshold and using this minimum mean attenuation value as a reference value. The method further comprises using a data library that contains gradient values for each of a range of possible temperature values to obtain a first gradient value, the first gradient value corresponding to the first temperature value, wherein each gradient value relates to the gradient of a linear approximation between mean attenuation and soot load at the corresponding temperature. The method involves using the reference value and the first gradient value to determine an axis intercept value for use as an offset value and adopting the offset value as a temperature-independent calibration value for the diesel particulate filter.

Provided is a diesel engine capable of regenerating a DPF even during no-load and/or light-load operation. In a DPF regeneration process, opening-degree reduction control S2 for an exhaust-air throttle valve is performed after a start condition S1 of the regeneration process of the DPF in which PM is deposited is satisfied. When exhaust air reaches a temperature equal to or higher than a predetermined after-injection permissible temperature TA, after-injection control is subsequently started S5. Post-injection control is started S7 after the exhaust air reaches a temperature equal to or higher than a predetermined post-injection permissible temperature TP by combustion of after-injection fuel. The PM deposited in the DPF is incinerated by the exhaust air increased in temperature by catalytic combustion of post-injection fuel in a valve downstream-side DOC.

The exhaust purification system of an internal combustion engine includes a filter trapping particulate matter in exhaust gas flowing through an exhaust passage of the internal combustion engine and supporting a three-way catalyst, and a filter regeneration part configured to perform regeneration processing for oxidizing and removing particulate matter deposited on the filter when predetermined conditions are satisfied. The filter regeneration part is configured to increase an NO concentration in exhaust gas flowing into the filter when the predetermined conditions are satisfied compared to when the predetermined conditions are not satisfied.

A method comprises determining that an aftertreatment system is in a cold-operation mode; initiating a low engine-out NOx (LEON) mode by controlling a component of a vehicle containing the aftertreatment system to decrease an instantaneous engine out NOx (EONOx) amount and to increase exhaust energy relative to a normal operation mode for an engine of the vehicle; receiving information indicative of an operating status of the vehicle during the LEON mode; disengaging the LEON mode; subsequent to disengaging the LEON mode, initiating a thermal management (TM) mode for the aftertreatment system, wherein the TM mode is initiated by controlling a component of the vehicle to increase fueling to the engine for a power level by reducing engine efficiency and directing excess fuel to the aftertreatment system; receiving information indicative of an operating status of the vehicle during the TM mode; and disengaging the TM mode.

A method (200) for operating a combustion engine (120) with a particle filter (130) is disclosed, wherein an exhaust gas flow of the combustion engine (120) is passed through the particle filter (130), a particle concentration in the exhaust gas flow is measured (220) downstream of the particle filter (130) and the combustion engine is operated at least depending on the measured particle concentration downstream of the particle filter.

A method, system, and apparatus relating to operating an internal combustion engine include steps or features for determining a performance threshold of a particulate filter disposed in an exhaust gas flow of the engine having a set time interval between regeneration events of the particulate filter; determining a rate at which the particulate filter is reaching the performance threshold; and controlling an exhaust gas characteristic to control the rate so that the performance threshold is reached at or just before an end of the time interval. In an embodiment, there are steps or features for interpreting a filter condition of the particulate filter; determining a particulate matter load rate of the filter as a function of the condition; determining a limit of an exhaust gas characteristic based on the load rate; and controlling engine operation to control the exhaust gas characteristic to satisfy the limit.