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.

A diesel-emissions reduction unit having an inlet adapted to receive an exhaust stream of the diesel engine; a diesel oxidation trap catalyst located adjacent the inlet; a dosing controller and an injection lance arranged to meter aqueous NH.sub.3 into the exhaust stream; a NOx concentration sensor and a NH.sub.3 concentration sensor with at least one oxidation catalyst panel arranged to isolate the NOx concentration sensor from NH.sub.3 in the exhaust stream; and an exhaust heater arranged to heat the exhaust stream of the diesel engine toward the inlet of the diesel emissions reduction unit.

A method for reducing deposits related to a reduction agent (RA) in a portion of an exhaust aftertreatment system (EAS) of an internal combustion engine (ICE) and comprising an injector for injecting the RA into said EAS, said portion located downstream of said injector, as seen in an intended direction of flow of exhaust gas in said EAS, said method comprising: identifying for said ICE, a future operating sequence (FOS) comprising a first temporal portion (t.sub.1) and a second temporal portion (t.sub.2) subsequent to t.sub.1, confirming that said FOS is suitable for reducing deposits and that said ICE operates in accordance with said FOS, in response to said confirming being affirmative, injecting a first dosage (d.sub.1) of RA into said EAS during at least a part of said t.sub.1 and injecting a second dosage (d.sub.2) of RA smaller than d.sub.1 into said EAS during at least a part of t.sub.2.

A method includes: initiating a low engine-out NOx (LEON) mode by controlling a component of a vehicle having an aftertreatment system to decrease an instantaneous engine-out NOx (EONOx) amount; comparing a temperature of the aftertreatment system during the LEON mode to a warm-operation threshold temperature; responsive to determining that the temperature of the aftertreatment system exceeds the warm-operation threshold temperature, disengaging the LEON mode; responsive to determining that the temperature of the aftertreatment system is below the warm-up operation threshold temperature, comparing information indicative of an operating status of the vehicle to a LEON exit threshold; and disengaging the LEON mode responsive to determining that the information indicative of the operating status of the vehicle during the LEON mode exceeds the LEON exit threshold.

A computer implemented method for anomality detection at a first nitrogen oxide (NOx) sensor forming part of an exhaust gas aftertreatment system (EATS) is provided. The EATS is coupled downstream of an internal combustion engine (ICE). The disclosed methodology applies manipulation of the ICE for detecting such a possible anomality.

A modular exhaust subsystem for purifying an exhaust gas feedstream of a compression-ignition internal combustion engine upstream of a base exhaust aftertreatment system includes a selective catalytic reduction (SCR) catalyst, and a first exhaust gas sensor and a first temperature sensor that are arranged to monitor the SCR catalyst. A reductant delivery system is arranged to inject a reductant upstream of the SCR catalyst. A controller is in communication with an engine-out exhaust gas sensor, a second exhaust gas sensor and a second temperature sensor that are arranged to monitor the base exhaust aftertreatment system. The controller controls the reductant delivery system to inject the reductant into the exhaust gas feedstream upstream of the SCR catalyst based upon inputs from the first and second exhaust gas sensors, the engine-out exhaust gas sensor, and the first and second temperature sensors.

A catalytic converter system having oxygen storage materials is disclosed and methods for determining whether to reactivate oxygen storage materials and monitoring failure events of the oxygen storage materials are also disclosed.

The present disclosure relates to a method for determining urea feeding in an exhaust gas aftertreatment system (100,200), the exhaust gas aftertreatment system (100,200) being connectable to an internal combustion engine (101,201) operating under an engine operating condition, the system (100,200) comprising a first Selective Catalytic Reduction (SCR1) system comprising a first selective reduction catalyst (SCR1c) and a first doser (103,203) configured for feeding urea upstream the SCR1 system, at least one Particulate Filter (PF) downstream the SCR1 system or as a substrate for the SCR1c and a second Selective Catalytic Reduction (SCR2) system downstream the PF, the SCR2 system comprising a second selective reduction catalyst (SCR2c) and a second doser (104,204) configured for feeding urea upstream the SCR2c, the method comprising the steps of estimating the amount of particles in the PF; and determining the amount of urea to be fed by the respective first and second doser (4,5) based on the engine operating condition and such that: a) the amount of particles in the PF is within a predefined particle amount range, and, b) the NOx level of the exhaust gas exiting the SCR2 system is within a predetermined NOx level range. The present disclosure also relates to an exhaust gas aftertreatment system (100,200) and a vehicle comprising the exhaust gas aftertreatment system (100,200), a computer program comprising program code means for performing the steps of the method, a computer readable medium carrying a computer program comprising program code means for performing the steps of the method and a control unit for controlling urea feeding in the exhaust gas aftertreatment system (100,200).

The present disclosure describes methods for evaluating ammonia storage capacity of a close-coupled SCR unit while remaining compliant with prescribed emissions limits, methods of controlling an emission aftertreatment system including multiple SCR units and emission management systems for a vehicle including an internal combustion engine and an emission aftertreatment system that includes two or more SCR units.

An exhaust aftertreatment system and associated method for purifying an exhaust gas feedstream of a lean-burn or other compression-ignition internal combustion engine is described. An instruction set is executable to determine an engine-out NO2 concentration upstream of an oxidation catalyst and determine a first parameter associated with O2 concentration. A consumption of oxygen in the oxidation catalyst due to oxidation reactions is determined, and a concentration of NO2 generated by the oxidation catalyst is determined based upon the consumption of oxygen in the oxidation catalyst. A concentration of NO2 downstream of the oxidation catalyst is determined. A NO2/NOx ratio in the exhaust gas feedstream downstream of the oxidation catalyst is determined based upon the concentration of NO2 downstream of the oxidation catalyst and the NOx concentration measured by the downstream NOx sensor. The oxidation catalyst is evaluated based upon the NO2/NOx ratio.