A reformer system may include a reformer device having a fuel inlet, an air inlet and a gas outlet, a first valve set coupled to the fuel inlet and configured to selectively supply a reformer fuel flow from an engine fuel flow to the fuel inlet, a second valve set coupled to the air inlet and configured to selectively supply a reformer air flow from a compressor outlet air flow to the air inlet, and a controller in electrical communication with the first valve set and the second valve set. The controller may determine a target reformer fuel flow based on a target gas flow, determine a target reformer air flow based on the reformer fuel flow and a target air-to-fuel ratio, adjust the reformer fuel flow according to the target reformer fuel flow, and adjust the reformer air flow according to the target reformer air flow.

Start-up method for heating a selective catalytic reduction (SCR) module in a hybrid propulsion system of a vehicle, comprising an electric motor operatively connected to an internal combustion engine producing exhaust gas, both electric motor and internal combustion engine being operable to power said vehicle, and said internal combustion engine being in fluid communication with an exhaust aftertreatment system having an exhaust passage and comprising the SCR module, said SCR module being disposed in said exhaust passage downstream of said engine and said electric motor, the method comprising the steps of: operating the engine in a start-up mode with a torque restriction on the engine, allowing the SCR module to convert NOx emission; supplying a surplus amount of a reducing agent to the exhaust gas at a position between the engine and the SCR module, the surplus amount of the reducing agent being larger than a required amount of reducing agent for converting NOx emission from the engine; heating said SCR module to a working temperature; and terminating the start-up mode, thereby terminating the torque restriction on the engine and the supply of the surplus amount of the reducing agent.

The invention relates to a method for operating an internal combustion engine installed in a vehicle, in particular a diesel engine, in which the instantaneous concentration of a pollutant contained in the exhaust gas, in particular the NO.sub.x concentration in the exhaust gas, is measured or calculated in the flow direction after an exhaust gas aftertreatment. Using the determined pollutant concentration, the predefined distance- and/or power-based compliance with pollutant limiting values in mg/km or mg/kWh are monitored by means of specifically influencing the operating parameters of the internal combustion engine and/or an exhaust gas after treatment system in regulated form.

An exhaust gas recirculation (EGR) control method includes a valve duty differentiated control including: detecting, by a controller, an engine operation region, a mixer region, and an external factor region as a valve control condition for an EGR valve duty correction variable for controlling an EGR system; applying, by the controller, the EGR valve duty correction variable to an EGR valve duty, which is set by a target air amount to an intake air amount, to calculate a minimum EGR valve duty; and outputting, by the controller, the calculated minimum EGR valve duty to an EGR valve as the EGR valve duty.

In order to adequately suppress both an increase in NOx emission amount and deterioration of fuel consumption rate, the present invention provides a fuel injection control information generation device equipped with: a test point information storage unit for holding test point information including a plurality of test points constituted by sets of engine speed, fuel injection amount, and oxygen concentration; and a control information generation unit for generating, for each test point included in the test point information, fuel injection control information in which the engine speed, fuel injection amount, and oxygen concentration of the test point are associated with an optimum fuel injection timing at which an index pertaining to the total of a fuel consumption rate and an NOx emission amount in the test point becomes the smallest.

A control system for fuel injection by predicting engine noise may include an engine noise predicting device configured to derive a predicted engine noise value in real time by a predicted engine noise coefficient which is pre-stored according to a currently measured combustion pressure value of an engine; and a combustion controller configured to determine a difference between the real-time predicted engine noise value derived by the engine noise predicting device and a target engine noise value for a current operation condition of the engine, and when the engine noise is determined as being degraded due to an abnormal combustion, configured to change the target engine noise value to control fuel injection according to the changed target engine noise value.

An emissions control system for a vehicle having an exhaust system with an exhaust gas conduit and a catalytic converter configured to receive exhaust gas from an engine is provided. In one example implementation, the system includes an engine controller configured to control the engine to adjust an air to fuel ratio (lambda) thereof. The engine controller is configured to operate the engine with at least one of the following lambda control strategies (i) a first control strategy comprising operating at a first reference lambda modified by a first percent kick, and a first rich lambda lag time shorter than a first lean lambda lag time, and (ii) a second control strategy comprising operating at a second reference lambda modified by a second percent kick, and a second rich lag time longer than a second lean lambda lag time, to thereby simultaneously meet predetermined NOx and CO emissions targets.

A chambered sparkplug carrier and a natural gas engine management system are provided for reducing NOx emissions of pre-chambered combustion natural gas engines. A method for retro-fitting a pre-chambered combustion natural gas engine with a chambered sparkplug is also described.

A method of implementing control logic of a compression-ignition engine is provided. A control part of the engine performs a calculation according to the control logic corresponding to an engine operating state in response to a measurement of a measurement part, controls a fuel injection part, a variable valve operating mechanism, an ignition part and a supercharger so that a G/F becomes leaner than a stoichiometric air fuel ratio and a A/F becomes equal to or richer than the stoichiometric air fuel ratio, while causing the supercharger to boost, and controls the ignition part so that unburnt mixture gas combusts by self-ignition after the ignition. The method includes determining a supercharging pressure P, and determining control logic defining a close timing IVC of an intake valve. When determining the control logic, the close timing IVC (deg.aBDC) is determined so that the supercharging pressure P (kPa) satisfies the following expression: P8.010.sup.11IVC.sup.61.010.sup.8IVC.sup.5+3.010.sup.7IVC.sup.44.010.sup.6IVC.sup.3+0.0068IVC.sup.20.3209IVC+116.63.

A system of controlling an engine provided with a dual continuously variable valve duration device may include the engine including a combustion chamber, an intake valve, an ignition switch provided in the combustion chamber, and an exhaust valve, the CVVD provided to adjust an intake duration of the intake valve and an exhaust duration of the exhaust valve, a warm-up catalytic converter (WCC) including a three-way catalyst (TWC) for purifying hydrocarbons, carbon monoxide, nitrogen oxides contained in the exhaust gas downstream of the engine, a Hydrocarbon (HC) trap disposed downstream of the warm-up catalytic converter for adsorbing and removing the hydrocarbons contained in the exhaust gas, an electrically heated catalyst disposed downstream of the HC trap and provided with a heating device, a three-way catalyst (TWC) disposed downstream of the electrically heated catalyst for purifying hydrocarbons, carbon monoxide, and nitrogen oxides contained in the exhaust gas, and a controller for adjusting an ignition timing of the ignition switch, the intake duration and the exhaust duration based on a driving condition of the vehicle.