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 control system for a vehicle includes a temperature sensor positioned downstream of an exhaust burner and upstream of an SCR catalyst in an exhaust system. The temperature sensor is configured to generate a measurement signal indicative a temperature of exhaust flowing through the exhaust system at an outlet of a DPF positioned downstream of the exhaust burner. An exhaust control module is configured to turn the exhaust burner on to heat the exhaust, monitor the temperature of the exhaust based on the measurement signal, subsequent to turning the exhaust burner on, turn the exhaust burner off based on an upper threshold temperature of the exhaust, and, subsequent to turning the exhaust burner off, turn the exhaust burner on based on a lower threshold temperature of the exhaust. The lower threshold temperature is less than the upper threshold temperature.

A method for checking operability of a first metering unit includes sending a control signal to a second metering unit to dispense a second quantity; comparing the quantity dispensed with the second quantity; sending a control signal to a second metering unit to introduce a third quantity; detecting the pressure drop caused by the introduction of the third quantity; sending a control signal to the first metering unit to introduce a first quantity; detecting the pressure drop caused by executing the control signal to introduce the first quantity; and ascertaining that the first metering unit is not functioning correctly if a difference between the pressure drop detected as a result of the execution of the control signal to introduce the first quantity and the pressure drop detected as a result of the execution of the control signal to introduce the third quantity is above a threshold.

An exhaust gas aftertreatment system includes a housing assembly and a reductant delivery system. The housing assembly includes an upstream housing, a first inlet tube, a second inlet tube, and a mixing housing. The first inlet tube is coupled to the upstream housing and configured to receive a first portion of exhaust gas from the upstream housing. The second inlet tube is coupled to the upstream housing and configured to receive a second portion of the exhaust gas from the upstream housing. The mixing housing is coupled to the first inlet tube and the second inlet tube. The mixing housing is configured to receive the first portion of the exhaust gas from the first inlet tube and receive the second portion of the exhaust gas from the second inlet tube. The mixing housing is separated from the upstream housing by the first inlet tube and the second inlet tube.

A multi-stage mixer includes a multi-stage mixer inlet, a multi-stage mixer outlet, a first flow device, and a second flow device. The multi-stage mixer inlet is configured to receive exhaust gas. The multi-stage mixer outlet is configured to provide the exhaust gas to a catalyst. The first flow device is configured to receive the exhaust gas from the multi-stage mixer inlet and to receive reductant such that the reductant is partially mixed with the exhaust gas within the first flow device. The first flow device includes a plurality of main vanes and a plurality of main vane apertures. The plurality of main vane apertures is interspaced between the plurality of main vanes. The plurality of main vane apertures is configured to receive the exhaust gas and to cooperate with the plurality of main vanes to provide the exhaust gas from the first flow device with a swirl flow.

A method for controlling urea injection in an exhaust aftertreatment system includes injecting urea at a flow rate upstream of the first catalytic reduction device; measuring a level of nitrogen oxides downstream of the first catalytic reduction device and upstream of the second catalytic reduction device; controlling the flow rate of the urea injection until the measured level of nitrogen oxides fulfils a predetermined condition; if the measured level of nitrogen oxides is decreasing in response to reducing the flow rate of the urea injection, reducing the flow rate of the urea injection, and controlling a flow rate of urea injection using the second urea injector upstream of the second catalytic reduction device according to the measured level of nitrogen oxides downstream of the first catalytic reduction device and upstream of the second catalytic reduction device.

A method to estimate the temperature of an electromagnetic actuator, which entails a preliminary step in which to define a first threshold value for the current or for the voltage; and define a characteristic curve of the actuator family in the plane temperature/time needed to reach the threshold value; a step in which to carry out a reference measurement, in which, using the characteristic curve, a reference time needed by the electromagnetic actuator to reach the first threshold value is associated with a known reference temperature; and a step in which to carry out a series of measurements in which to determine the time needed by the electromagnetic actuator to reach the first threshold value, calculate the deviation between the time needed by the electromagnetic actuator to reach the first threshold value and the reference time; and determine the temperature of the electromagnetic actuator, using the characteristic curve, by associating the temperature of the electromagnetic actuator with the sum of the deviation and of the reference time.

An exhaust control system of a vehicle includes a fuel injector configured to inject fuel into a combustion chamber of a burner of an exhaust system upstream of a selective catalytic reduction (SCR) catalyst; an air pump configured to pump air into the combustion chamber of the burner; a spark plug configured to ignite an air/fuel mixture within the combustion chamber of the burner; a fuel control module configured to, while an engine is off before an engine startup, selectively actuate the fuel injector and begin fuel injection; a pump control module configured to, while the engine is off before the engine startup, selectively turn on the air pump; and a spark control module configured to, while the engine is off and before the engine startup, selectively apply power to the spark plug and begin providing spark.

Disclosed is a method for determining a temperature of a solenoid injector including a coil and a needle when the solenoid injector is in a non-injection phase, the method being characterized in that it includes the following steps: powering the solenoid injector coil using an electric generator for a period of time tvoltage strictly shorter than a period of time tlim corresponding to a time for which the coil is under power causing the needle to open; measuring at least one value icoil of the current of the solenoid injector coil using a current measurement sensor when the coil is powered; and determining a temperature of the solenoid injector from the at least one value icoil of the current of the solenoid injector coil.

The disclosure relates to a self-adaptive oil spraying control system and method for a biodiesel engine. The control system includes an exhaust pipe, a gas sensor, a control module and an oil sprayer, wherein the exhaust pipe is connected to the oil sprayer, the gas sensor is mounted in the exhaust pipe, and the gas sensor and the oil sprayer are connected to the control module respectively. According to the control method, a main spray advance angle of the engine is subjected to closed-loop control directly through comparison between an idling steady state NO.sub.x emission signal and an idling steady state NO.sub.x emission value of pure diesel when the engine uses the biodiesel, so that emission of NO.sub.x in the exhaust is reduced. Compared with the prior art, the disclosure has the advantages of no need of detecting a biodiesel ratio, high efficiency, good effect and the like.