A method to control an internal combustion engine provided with an exhaust system for the exhaust gases of a vehicle having an exhaust duct and an exhaust gas after-treatment system comprising at least one catalytic converter arranged along the exhaust duct; a burner suited to introduce the exhaust gases into the exhaust duct to speed up the heating of said at least one catalytic converter, wherein a combustion chamber is defined inside the burner which receives fuel from an injector, designed to inject the fuel inside the combustion chamber and the fresh air by means of an air feeding circuit provided with a pumping device that feeds the air, a shut-off valve arranged upstream of the burner and a mass air flow sensor interposed between the pumping device and the shut-off valve; the method provides the following steps: calculating the thermal power required to reach the nominal operating temperature of said at least one catalytic converter; determining the objective air flow rate to be fed to the burner to obtain said thermal power required to reach the nominal operating temperature of said at least one catalytic converter; determining the nominal number of revolutions with which to operate the pumping device by means of a map depending on the objective air flow rate, on the ambient pressure, on the ambient temperature and on the pressure of the air entering the burner; determining a closed-loop contribution of the number of revolutions with which to operate the pumping device by means of a PID controller which tries to zero a difference between the objective air flow rate and the air flow rate detected by the mass air flow sensor; determining a further contribution of the number of revolutions with which to operate the pumping device depending on the integral action of the PID controller under stationary conditions; and determining the actual number of revolutions with which to operate the pumping device by the sum of the nominal number of revolutions, the closed-loop contribution of the number of revolutions with which to operate the pumping device and the further contribution of the number of revolutions with which to operate the pumping device.

A method to control an internal combustion engine provided with an exhaust system for the exhaust gases of a vehicle having an exhaust duct and an exhaust gas after-treatment system comprising at least one catalytic converter arranged along the exhaust duct; a burner suited to introduce the exhaust gases into the exhaust duct to speed up the heating of said at least one catalytic converter, wherein a combustion chamber is defined inside the burner which receives fuel from an injector, designed to inject the fuel inside the combustion chamber and the fresh air by means of an air feeding circuit provided with a pumping device that feeds the air, a shut-off valve arranged upstream of the burner and a mass air flow sensor interposed between the pumping device and the shut-off valve; the method provides the following steps: calculating the thermal power required to reach the nominal operating temperature of said at least one catalytic converter; determining the objective air flow rate to be fed to the burner to obtain said thermal power required to reach the nominal operating temperature of said at least one catalytic converter; determining the nominal number of revolutions with which to operate the pumping device by means of a map depending on the objective air flow rate, on the ambient pressure, on the ambient temperature and on the pressure of the air entering the burner; determining a closed-loop contribution of the number of revolutions with which to operate the pumping device by means of a PID controller which tries to zero a difference between the objective air flow rate and the air flow rate detected by the mass air flow sensor; determining a further contribution of the number of revolutions with which to operate the pumping device depending on the integral action of the PID controller under stationary conditions; and determining the actual number of revolutions with which to operate the pumping device by the sum of the nominal number of revolutions, the closed-loop contribution of the number of revolutions with which to operate the pumping device and the further contribution of the number of revolutions with which to operate the pumping device.

A method to control an internal combustion engine having an exhaust duct and an exhaust gas after-treatment system comprising at least one catalytic converter arranged along the exhaust duct; an oxygen sensor housed along the exhaust duct and arranged upstream of said at least one catalytic converter; and a burner suited to introduce the exhaust gases into the exhaust duct upstream of the oxygen sensor the method provides the steps of identifying the operation phases in which the internal combustion engine is turned off and the burner is turned on so that the oxygen sensor is exclusively hit by the exhaust gases produced by the burner; acquiring the signal generated by the oxygen sensor; and using the signal generated by the oxygen sensor to determine the objective fuel flow rate and the objective air flow rate to be fed to the burner.

A method to control an internal combustion engine having an exhaust duct and an exhaust gas after-treatment system comprising at least one catalytic converter arranged along the exhaust duct; an oxygen sensor housed along the exhaust duct and arranged upstream of said at least one catalytic converter; and a burner suited to introduce the exhaust gases into the exhaust duct upstream of the oxygen sensor the method provides the steps of identifying the operation phases in which the internal combustion engine is turned off and the burner is turned on so that the oxygen sensor is exclusively hit by the exhaust gases produced by the burner; acquiring the signal generated by the oxygen sensor; and using the signal generated by the oxygen sensor to determine the objective fuel flow rate and the objective air flow rate to be fed to the burner.

An exhaust gas aftertreatment system for an internal combustion engine has an exhaust system that can be connected to an outlet of the internal combustion engine. A three-way catalytic converter that is situated close to the engine and, downstream from the three-way catalytic converter that is situated close to the engine, a second catalytic converter and a particle reduction device are arranged in the direction in which an exhaust gas of the internal combustion engine flows through an exhaust gas channel of the exhaust system. A fuel injector is arranged on the exhaust gas channel so as to inject fuel downstream from the three-way catalytic converter that is situated close to the engine and upstream from the second catalytic converter, and the exhaust system comprises a secondary air system with which secondary air can be blown into the exhaust gas channel downstream from the three-way catalytic converter that is situated close to the engine and upstream from the second catalytic converter.

An exhaust gas aftertreatment system for an internal combustion engine has an exhaust system that can be connected to an outlet of the internal combustion engine. A three-way catalytic converter that is situated close to the engine and, downstream from the three-way catalytic converter that is situated close to the engine, a second catalytic converter and a particle reduction device are arranged in the direction in which an exhaust gas of the internal combustion engine flows through an exhaust gas channel of the exhaust system. A fuel injector is arranged on the exhaust gas channel so as to inject fuel downstream from the three-way catalytic converter that is situated close to the engine and upstream from the second catalytic converter, and the exhaust system comprises a secondary air system with which secondary air can be blown into the exhaust gas channel downstream from the three-way catalytic converter that is situated close to the engine and upstream from the second catalytic converter.

Aspects of the present invention relate to a valve seat (20) for a poppet valve of an internal combustion engine, wherein the poppet valve comprises a head and a stem behind the head, the valve seat comprising: an aperture (21) configured to form a seal with the head of the poppet valve when the poppet valve is in a closed position; and a peripheral body (22) defining, at least in part, one or more ports (23) shaped like e.g. grooves and sized to enable injection of liquid or gas from a cylinder head of the internal combustion engine into a gas stream behind the head of the poppet valve.

Systems and methods for controlling a regeneration process of catalyst(s) are disclosed. The method includes receiving, via Kalman filter, initial estimation from a previous instance of time. The initial estimation includes one or more first estimated inside temperature(s) and/or first estimated outlet temperature of A/T catalyst. An output from a simulation model may be generated to calculate a mean and covariance. Sensor measurement covariance may be compared against the mean and covariance of the output to update Kalman filter gain and process covariance. A weighted average may be calculated between sensor measurements and mean of the output to generate a second estimation for the next instance of time, wherein weight is based on Kalman filter gain. The second estimation includes one or more second estimated inside temperature(s) and/or second estimated outlet temperature of A/T catalyst to control the mass flow rate in diesel engine via a closed loop control system.

A method to control an exhaust gas after-treatment system for an exhaust system of an internal combustion engine having at least one catalytic converter and a burner, which is suited to introduce exhaust gases into an exhaust duct so as to speed up the heating of said at least one catalytic converter; the method entails inserting an indicator in a dashboard of a vehicle provided with the internal combustion engine so that it provides a driver of the vehicle with indications concerning the burner; and keeping the indicator turned on during a starting step, during which the temperature of said at least one catalytic converter is lower than an activation temperature.

A dosing and mixing arrangement includes a mixing tube having a constant diameter along its length. At least a first portion of the mixing tube includes a plurality of apertures. The arrangement also includes a swirl structure for causing exhaust flow to swirl outside of the first portion of the mixing tube in one direction along a flow path that extends at least 270 degrees around a central axis of the mixing tube. The arrangement is configured such that the exhaust enters an interior of the mixing tube through the apertures as the exhaust swirls along the flow path. The exhaust entering the interior of the mixing tube through the apertures has a tangential component that causes the exhaust to swirl around the central axis within the interior of the mixing tube. The arrangement also includes a doser for dispensing a reactant into the interior of the mixing tube.