An exhaust aftertreatment system and associated system for purifying an exhaust gas feedstream of a lean-burn engine includes an oxidation catalyst that is arranged upstream of a selective catalytic reduction (SCR) catalyst. A first NOx sensor is arranged upstream, and a second NOx sensor is arranged downstream of the oxidation catalyst. A controller is arranged to monitor the oxidation catalyst based upon inputs from the first and second NOx sensors. A first NOx parameter is determined via the first NOx sensor, and a second NOx parameter is determined via the second NOx sensor. An NO2 parameter is determined based upon the first NOx parameter, the second NOx parameter, a first relationship for the first and second NOx sensors, and a second relationship for the first and second NOx sensors. The NO2 production of the oxidation catalyst is evaluated based upon the NO2 parameter.

Disclosed is a method for diagnosing a first exhaust treatment component for treatment of an exhaust gas stream comprising means for oxidizing nitric oxide into nitrogen dioxide. A first reduction catalytic converter is arranged upstream said means for oxidizing nitric oxide into nitrogen dioxide, and a second reduction catalytic converter is arranged downstream said means. A reagent is for reduction of nitrogen oxides in said first catalytic converter, and a first sensor measures an occurrence of nitrogen oxide downstream said means but upstream said second reduction catalytic converter. The method comprises: causing a supply of reagent upstream said first reduction catalytic converter to an extent exceeding the extent to which reagent is consumed by the first reduction catalytic converter, determining a first measure of the occurrence of reagent downstream said means for oxidizing, and diagnosing said means for oxidizing nitric oxide into nitrogen dioxide based on said first measure.

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.

An exhaust gas treatment system includes an exhaust gas pathway configured to receive exhaust gas from an internal combustion engine. The exhaust gas treatment system further includes a treatment element configured to reduce an emissions component of the exhaust gas, and a sample collector positioned within the exhaust gas pathway downstream of the treatment element. The sample collector includes a plurality of inlet openings spaced about a periphery of the exhaust gas pathway and configured to receive a sample of exhaust gas from the exhaust gas pathway, and an outlet in fluid communication with the plurality of inlet openings. A sensor located at the outlet of the sample collector is configured to measure a characteristic of the sample.

There is described a cooling system for a tractor exhaust after treatment. The cooling system comprises a urea supply module have a first port and a second port, and an exhaust system, wherein the exhaust system comprises an exhaust pipe and a catalytic converter. An engine cooling system comprises a heat exchanger, a fan, a coolant pump, a coolant feed line, and a coolant return line. The coolant feed line comprises a first portion and a section portion, and the coolant return line comprises a primary portion and a secondary portion. Each of the first portion, the second portion, the primary portion and the secondary portion are oriented generally vertically. The second portion is in fluid communication with the first port, and the secondary portion is in fluid communication with the second port. A bypass line provides fluid communication between the second and secondary portions

An exhaust treatment assembly for receiving exhaust gas from a motor vehicle includes a mix pipe, a sheath, and a heater. The mix pipe at least partially defines a passage adapted to receive the exhaust gas and a chemical reductant. The sheath includes a first end fluidly sealed to the mix pipe. At least a portion of the sheath is radially spaced apart from the mix pipe to at least partially define a gap. The heater is disposed in the gap. The heater is adapted to heat a reductant impingement surface.

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.

A reaction device of a marine SCR system comprises a conveying unit (110), a reaction chamber (120), at least one catalyst module (130), and an air homogenization chamber (140), wherein, the conveying unit (110) includes an input pipeline (111) and an output pipeline (112) sleeved outside the input pipeline (111). One end of the reaction chamber (120) is connected to the conveying unit (110). The reaction chamber (120) comprises an inner cylinder (121) and an outer cylinder (122) sleeved outside the inner cylinder (121), the inner cylinder (121) is in communication with the input pipeline (111), and the outer cylinder (122) is in communication with the output pipeline (112). The catalyst module (130) is provided between the inner cylinder (121) and the outer cylinder (122). The air homogenization chamber (140) is connected to the other end of the reaction chamber (120) and is in communication with both the inner cylinder (121) and the outer cylinder (122). With the reaction device of the marine SCR system whereby the outer cylinder is sleeved outside the inner cylinder, flue gas from the inner cylinder is turned by the air homogenization chamber and then flows back into the outer cylinder. This can not only substantially reduce the size of the reaction device to improve the integration of the SCR system, but also allow the flue gas to turn in the air homogenization chamber and then flow back, so that the flue gas and a reducing agent can be fully mixed in the air homogenization chamber to improve the catalytic reaction efficiency.

An exhaust gas system for an internal combustion engine includes at least one component which delimits an exhaust gas flow volume via an outer wall and, on an inner side of the outer wall which faces the exhaust gas flow volume, supports at least one shielding element. An intermediate space is formed between the outer wall and the shielding element. At least one connecting molding on the shielding element is directed toward the outer wall and is connected fixedly to the outer wall.

A liquid reductant injector nozzle includes a first portion defining a hollow cylindrical static chamber, in fluid communication with second portion defining a hollow frustoconical converging section, which is in turn in fluid communication with a sharp edged type discharge orifice. The hollow cylindrical static chamber is in reductant receiving communication with a reductant source, and has a first and second circular opening having equal diameters. The second circular opening is downstream of the first circular opening. The hollow frustoconical converging section is in reductant receiving communication with the hollow cylindrical static chamber via the second circular opening. Reductant received from the reductant source is discharged through the discharge orifice. A sidewall of the hollow cylindrical static chamber and a frustum side of the frustoconical converging section define an angle of convergence of the liquid reductant injector nozzle relative to a plane of the second circular opening.