Methods and systems for operating an engine with a pump that is driven via the engine are described. In one example, start of opening of an injector that supplies a fluid to an engine exhaust system is timed based on a period of the pump so that the output of the fluid injector may be repeatable in the presence of fluid pressure oscillations that are periodic with pump rotation.

A heating system includes at least one electric heater disposed within a fluid flow system and a control device that is configured to determine a temperature of the at least one electric heater based on a model, at least one fluid flow system input, and at least one heater input. The at least one heater input includes at least one physical characteristic of the heating system, the at least one physical characteristic includes at least one of a resistance wire diameter, a heater insulation thickness, a heater sheath thickness, a conductivity, a specific heat and density of the material of the heater, an emissivity of the heater and the fluid flow pathway, and combinations thereof. The control device is configured to provide power to the at least one electric heater based on the temperature of the at least one electric heater.

An aftertreatment system connected downstream an internal combustion engine arrangement for receiving exhaust gases conveyed from the internal combustion engine arrangement during operation thereof, wherein the aftertreatment system comprises first and second catalytic devices in series, wherein a gap is there between.

A method of detecting a need for regeneration of an exhaust particulate filter is described. A first pressure drop is detected in a flow section of an exhaust system which includes the exhaust particulate filter. In addition, an exhaust gas temperature is determined. An exhaust gas mass flow flowing through the exhaust particulate filter is then calculated on the basis of the exhaust gas temperature and the pressure drop. Furthermore, a second pressure drop at the exhaust particulate filter is determined. A need for regeneration is detected when the second pressure drop exceeds a predefined pressure limit value that is dependent on the exhaust gas mass flow. Moreover, an exhaust system for an internal combustion engine is presented which includes an exhaust particulate filter.

An aftertreatment system (100) connected downstream an internal combustion engine arrangement (102) for receiving exhaust gases conveyed from the internal combustion engine arrangement (102) during operation thereof, wherein the aftertreatment system comprises first and second catalytic devices in series, wherein a gap is there between.

Disclosed is a device for injecting ammonia in gaseous form into an exhaust line of a combustion engine, the device including a supervisor, an evaporation chamber incorporating a heater for heating a quantity of reducing agent thus releasing ammonia in gaseous form that exits the evaporation chamber via a pipe opening into the exhaust line. The control supervisor is associated with an internal first pressure sensor housed in the evaporation chamber and with a second pressure sensor intended to be housed in the exhaust line, including a calculator calculating a quantity of ammonia to be injected into the exhaust line at a given instant as a function of the pressure values from the first and second pressure sensors.

A system for determining an exhaust flow rate of an exhaust gas produced by an engine comprises a first sensor configured to measure an amount of NOx gases in the exhaust gas. A controller is communicatively coupled to the first sensor. The controller is configured to receive a first sensor signal from the first sensor. The controller is also configured to receive a fuel rate signal corresponding to a rate of fuel consumption by the engine. The controller is configured to determine an air-fuel ratio from the first sensor signal and determine a fuel rate from the fuel rate signal. Furthermore, the controller is configured to determine the exhaust flow rate from the air-fuel ratio and the fuel rate.

Methods, apparatuses, and systems for estimating exhaust air mass-flow in an aftertreatment system. An embodiment includes a selective catalytic reduction (SCR) system including at least one catalyst, a differential pressure (dP) sensor operatively coupled to the SCR system, a temperature sensor, and a controller. The dP sensor is configured to measure a value of a differential pressure across the SCR system, determine a first output value from the dP sensor, and a first temperature output value from the temperature sensor. The first output value is indicative of the value of the differential pressure across the SCR system. The first temperature output value is indicative of a temperature of the SCR system. The controller is further configured to estimate an exhaust air mass-flow output from the aftertreatment system using the first output value from the dP sensor and the first temperature output value from the temperature sensor.

Disclosed is a device for injecting ammonia in gaseous form into an exhaust line of a combustion engine, the device including a supervisor, an evaporation chamber incorporating a heater for heating a quantity of reducing agent thus releasing ammonia in gaseous form that exits the evaporation chamber via a pipe opening into the exhaust line. The control supervisor is associated with an internal first pressure sensor housed in the evaporation chamber and with a second pressure sensor intended to be housed in the exhaust line, including a calculator calculating a quantity of ammonia to be injected into the exhaust line at a given instant as a function of the pressure values from the first and second pressure sensors.

The invention relates to a regeneration air system for an exhaust aftertreatment system of an internal combustion engine and to such an exhaust aftertreatment system. The regeneration air system comprises a regeneration air delivery element, a regeneration air duct, and a regeneration air valve. A sensor system is provided in the regeneration air duct with which a regeneration air mass flow {dot over (m)}.sub.SL can be determined exactly. The exhaust aftertreatment system comprises an exhaust system with an exhaust duct in which, in the direction of flow of an exhaust gas through the exhaust duct, a three-way catalytic converter is arranged underhood and a four-way catalytic converter is arranged downstream. A provision is made that an intake point for the regeneration air from the regeneration air system is formed on the exhaust duct downstream from the underhood three-way catalytic converter and upstream from the four-way catalytic converter.