An exhaust purification system is provided with a NOx-occlusion-reduction-type catalyst 32 that occludes NOx in exhaust when the exhaust is in a lean state and reduces and purifies the occluded NOx when the exhaust is in a rich state, and a NOx purge rich control unit 140 for reducing and purifying NOx occluded in the NOx-occlusion-reduction-type catalyst 32 by putting the exhaust into the rich state by repetitively performing fuel injection control of at least one of post injection and exhaust pipe injection at a predetermined interval.

An exhaust purification system is provided with a NOx-occlusion-reduction-type catalyst and a NOx purge rich control unit that executes NOx purge in a case where a catalyst temperature of the NOx-occlusion-reduction-type catalyst is equal to or higher than a catalyst temperature threshold value and a NOx occlusion amount of the NOx-occlusion-reduction-type catalyst is equal to or higher than an NOx occlusion amount threshold value and executes the NOx purge even when the catalyst temperature is lower than a catalyst temperature threshold value in a case where the NOx occlusion amount is equal to or greater than the occlusion amount threshold value, a fuel injection amount resulting from an accelerator operation is equal to or greater than an injection amount threshold value, and an exhaust temperature detected by a first exhaust temperature sensor is equal to or higher than an exhaust temperature threshold value.

A diesel exhaust fluid (DEF) delivery system and method for operating same. The method includes controlling a pump to operate at an idle speed to pressurize a pressure line. The method includes controlling a backflow dosing module (BFDM) valve to open to allow an amount of the DEF to flow into a fluid storage tank through a backflow line. The method includes determining a dosing request, a first dosing actuation request for the first dosing valve and a second dosing actuation request for the second dosing valve based on the dosing request. The method includes, when a sum of the first and second dosing actuation requests is less than 100%, controlling the BFDM valve to close when either of the first and second dosing valves is open; and controlling the BFDM valve to open when the first dosing valve is closed and the second dosing valve is closed.

A method for metering a reactant into an exhaust gas path of an internal combustion engine, wherein the reactant is introduced into an area of the exhaust gas path in which pressure surges in the exhaust gas stream, generated by a charge exchange of the internal combustion engine, contribute to breakdown of droplets of the reactant, wherein a metering device for metering the reactant is activated at a variable metering frequency, depending on an operating point of the internal combustion engine.

An exhaust gas control apparatus includes a first catalyst, a filter, and an electronic control unit. The electronic control unit is configured to alternately execute lean control and rich control multiple times. The lean control is control for, over a period longer than a period from when a target air-fuel ratio is set to a predetermined lean air-fuel ratio until an air-fuel ratio of exhaust gas flowing out from the first catalyst becomes greater than the stoichiometric air-fuel ratio, setting the target air-fuel ratio to the predetermined lean air-fuel ratio. The rich control is control for, over a period longer than a period from when the target air-fuel ratio is set to a predetermined rich air-fuel ratio until the air-fuel ratio of exhaust gas flowing out from the first catalyst becomes smaller than the stoichiometric air-fuel ratio, setting the target air-fuel ratio to the predetermined rich air-fuel ratio.

Temperature measuring device for measuring the temperature of a member, the member including a component controlled by a control signal, active at most during at least one limited activity interval, and transmitted to the component via two wires, a temperature probe connected to the two wires, in parallel with the component, and a diode, connected between a terminal of the component and a terminal of the probe connected to the same wire, in order to allow the passage of a current in the component only in a first direction, the temperature measurement being performed by a current flowing in a second direction, opposite to the first direction, outside of the activity interval.

A power apparatus including a reducing agent supply control system includes: an engine configured to emit exhaust gas containing nitrogen oxide by burning air and fuel at a preset air-fuel ratio; an exhaust passage configured such that the exhaust gas emitted by the engine moves therethrough; a pressure sensor configured to actually measure the pressure of air which is supplied to the engine; a nitrogen oxide concentration sensor installed on the exhaust passage, and configured to measure the nitrogen oxide (NOx) concentration of the exhaust gas; a reducing agent supply unit configured to supply a reducing agent to the exhaust gas which moves along the exhaust passage; and a control unit configured to determine the amount of reducing agent to be supplied based on information received from the pressure sensor and the nitrogen oxide concentration sensor, and to control the reducing agent supply unit.

A method for controlling an exhaust gas treatment system is provided. The exhaust gas treatment system includes an exhaust gas stream supplied by an exhaust gas source to a selective catalytic reduction device, and a reductant supply source utilizing a volumetric pump. The exhaust gas source can include an internal combustion engine (ICE), such as a gasoline or diesel ICE. The method for controlling an exhaust gas treatment system includes commanding a reductant dosing quantity, determining a volumetric pump energizing time, determining an energizing time correction, and energizing the pump. The volumetric pump can comprise pump logic, and the volumetric pump energizing time can be determined by the pump logic. The energizing time correction can be determined using a calibration table. The calibration table can prescribe an energizing time correction based on a current pump pressure and the commanded dosing quantity.

An exhaust purification system is provided with a NOx-occlusion-reduction-type catalyst and a NOx purge rich control unit that executes NOx purge in a case where a catalyst temperature of the NOx-occlusion-reduction-type catalyst is equal to or higher than a catalyst temperature threshold value and a NOx occlusion amount of the NOx-occlusion-reduction-type catalyst is equal to or higher than an NOx occlusion amount threshold value and executes the NOx purge even when the catalyst temperature is lower than a catalyst temperature threshold value in a case where the NOx occlusion amount is equal to or greater than the occlusion amount threshold value, a fuel injection amount resulting from an accelerator operation is equal to or greater than an injection amount threshold value, and an exhaust temperature detected by a first exhaust temperature sensor is equal to or higher than an exhaust temperature threshold value.

A system for controlling reductant spray momentum for a target spray distribution includes an exhaust system having an exhaust conduit with exhaust flowing therethrough, a reductant injection system for injecting reductant into the exhaust flowing through the exhaust system based on one or more injection parameters, a reductant supply system for supplying reductant to the reductant injection system based on one or more supply parameters, and a controller. The controller is configured to access current vehicle, engine, exhaust, or reductant condition parameters, determine one or more control parameters based on a control model and the accessed current vehicle, engine, exhaust, or reductant condition parameters, and modify a value of the one or more injection parameters or the one or more supply parameters to control the reductant spray.