Volvo Lastvagnar Ab

Volvo Technology Corporation

Volvo Truck Corporation

Christer Alm

Hans Bernler

Andreas Hinz

Per Larsson

Ingemar Eckerström

Johan Bengtsson

Carl Landberg

Gote Hansson

A method and internal combustion engine system are provided for keeping an exhaust gas aftertreatment system within its working temperature range during an idle or motoring engine operation mode of an internal combustion engine. The method includes sensing the temperature of the gas at the gas intake side of the internal combustion engine and/or of the exhaust gas; determining whether or not the sensed temperature value is in a predetermined temperature interval or below a predetermined temperature threshold; determining whether the internal combustion engine is in idle or motoring engine operation mode; in case the internal combustion engine is determined to be in an idle or motoring engine operation mode, controlling the temperature of the gas at the gas intake side of the internal combustion engine to be within the predetermined temperature range or below the predetermined temperature threshold by recirculating exhaust gas through a connecting duct by controlling at least one valve.

Method and internal combustion engine system for keeping an exhaust gas aftertreatment system within its working temperature range

An operating method of an exhaust gas aftertreatment system including at least a particulate filter for retaining soot from the exhaust gas of an engine and a deNOx catalytic converter for reducing nitrogen oxide in the exhaust gas of the engine is provided. Operation regimes of the particulate filter and of the deNOx catalytic converter are synchronized with respect to each other for performing regeneration of the particulate filter while the catalytic converter provides a nitrogen oxide conversion efficiency above a predetermined limit.

Operating method for an exhaust aftertreatment system and exhaust aftertreatment system

A method is provided for controlling an exhaust gas temperature of an engine of a vehicle during interruption of fuel supply to the engine, wherein the engine drives a driveline of the vehicle. The method involves alternating between two or more operational modes, wherein at least one of the operational modes maintains a higher exhaust temperature than the one or more other operational modes.

Method for controlling an exhaust gas temperature

An exhaust gas after treatment system includes a diesel particulate filter unit (DPFU) provided downstream of a diesel engine, a selective catalytic reduction (SCR) arrangement provided in fluid communication with said DPFU, a first injector for feeding reducing agent into the exhaust gas provided downstream of said DPFU and upstream of said SCR, at least one NOx sensor provided downstream of said SCR for providing at least one NOx signal to a NOx coordinator, at least one temp sensor provided upstream and/or downstream of said SCR for providing at least one temp signal to said NOx coordinator, wherein said NOx coordinator is provided for switching said diesel engine into a high NOx mode or a low NOx mode depending on the values of the at least one NOx signal and the at least one temp signal.

Exhaust gas after treatment system

A method is provided for maintaining the heat in an exhaust after treatment system connected to the exhaust pipe of an internal combustion engine. The engine is used to propel a vehicle and is equipped with a valve-controlled EGR duct for the adjustable recirculation of exhaust gases from the exhaust side of the engine to its induction side. According to the invention, it is detected that neither the braking system nor the throttle control mechanism of the vehicle is activated and that the vehicle is being driven at a speed in excess of a predetermined value. After this, the gas flow through the EGR duct is regulated so that the gas flow to the exhaust aftertreatment system is reduced to a level which is less than about 50% of the gas flow to the exhaust aftertreatment system with shut-off EGR valve.

Method for internal combustion engine with exhaust recirculation

A method of controlling torque changes in a direct injection diesel engine having a control unit which controls the amount of fuel in the engine combustion chambers depending on signals fed into the control unit representing at least accelerator pedal position and engine speed. When the accelerator pedal is depressed, for example, thereby requesting a torque (tq), which exceeds a predetermined upper torque limit (b) stored in the control unit, the torque is first controlled up to a lower torque limit (c) stored in the control unit and from there gradually to the upper torque limit (b), from which the torque is then released up to the torque requested by the driver with the accelerator pedal.

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Göteborg, Sweden

Christer Alm