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.

There is provided: a NOx occlusion reduction-type catalyst that is provided in an exhaust passage of an internal combustion engine, occludes NOx in exhaust when the exhaust is in a lean state, and reduces and purifies the occluded NOx when the exhaust is in a rich state; an exhaust injector that is provided in the exhaust passage and is positioned further upstream than the NOx occlusion reduction-type catalyst; a NOx-purging control unit that performs NOx purging of reducing and purifying the NOx occluded in the NOx occlusion reduction-type catalyst by lowering the exhaust to a prescribed target lambda by fuel injection by the exhaust injector; and a NOx-purging-prohibition processing unit that inhibits performance of the NOx purging in a case where the exhaust cannot be lowered to the target lambda even if the fuel injection is performed at a maximum limit injection amount of the exhaust injector.

An exhaust gas control apparatus has an exhaust gas control element other than an SCR catalyst. A temperature increase treatment unit executes temperature increase treatment that increases temperature of exhaust gas flowing into the exhaust gas control apparatus so as to increase the temperature of the exhaust gas control element to a specified target temperature. In this case, when operation of the internal combustion engine is stopped while the temperature increase treatment unit is not executing the temperature increase treatment, addition of an additive to the SCR catalyst from an addition valve is executed after operation stop of the internal combustion engine. When operation of the internal combustion engine is stopped while the temperature increase treatment unit is executing the temperature increase treatment, addition of the additive to the SCR catalyst from the addition valve is not executed after operation stop of the internal combustion engine.

A method of calculating a nitrogen oxide (NOx) mass reduced from a lean NOx trap (LNT) during regeneration includes calculating a C3H6 mass flow used to reduce the NOx among a C3H6 mass flow flowing into the LNT of an exhaust purification device, calculating a NH3 mass flow used to reduce the NOx among a NH3 mass flow generated in the LNT, calculating a reduced NOx mass flow based on the C3H6 mass flow used to reduce the NOx and the NH3 mass flow used to reduce the NOx, and calculating the reduced NOx mass by integrating the reduced NOx mass flow over a regeneration period.

A work vehicle includes an engine, a battery, an exhaust gas purification system or device, and a notification device. The exhaust gas purification system or device is capable of performing a purification process purifying exhaust gas of the engine, and operates with electric power from the battery and performs an end process. The notification device provides notification that the exhaust gas purification system or device is performing the end process or that the end process is completed.

An exhaust aftertreatment system for an internal combustion engine includes an outer casing defining an exhaust flow path for exhaust gases from the internal combustion engine, a selective catalytic reduction unit provided in the exhaust flow path for reducing nitrogen oxides, a urea dosing device for adding urea to the exhaust flow upstream of the selective catalytic reduction unit, and a rotatable mixer device for mixing the urea with exhaust gases upstream of the selective catalytic reduction unit. The exhaust aftertreatment system further comprises an air inlet valve provided upstream of the mixer device for introducing air into the exhaust flow path, and an electric motor arranged for rotating the mixer device to create a suction of air into the exhaust flow path via the air inlet valve.

A selective catalytic reduction system includes a reducing agent injection module installed in an exhaust pipe through which an exhaust gas is discharged from an engine and configured to inject a reducing agent into the exhaust pipe, a temperature calculator configured to calculate a temperature of the reducing agent injection module using temperature-related information of the reducing agent injection module, and a temperature controller configured to control to increase a reducing agent injection amount of the reducing agent injection module when the calculated temperature.

A method for an SCR system comprising a dosing unit (250) for dosing reducing agent into an engine exhaust duct (290) upstream of a SCR catalytic converter (270) for reducing the NOx level in an exhaust flow from the engine. The SCR system comprises a pressurizing device (230) for feeding reducing agent from a container (205) to the dosing unit (250) arranged so as to dose reducing agent to the exhaust duct (290) under pressure. The method includes the step of: reducing, during periods of non-continuous dosing of reducing agent during continued maintained operation of the pressurizing device (230), the pressure (s301; s320) of the reducing agent at the dosing unit (250) compared to the pressure during continuous dosing. Also a computer program product containing program code (P) for a computer (200; 210) for implementing a method according to the invention. The invention also concerns an SCR system and a motor vehicle that is equipped with that system.

An exemplary vehicle exhaust system includes, among other things, a housing defining a fluid chamber and at least one pressure sensor positioned within the fluid chamber. The housing has a fluid inlet configured to receive fluid from a fluid supply and a fluid outlet. A heater heats fluid supplied from the fluid supply such that heated fluid can be injected into a vehicle exhaust component via the fluid outlet. A controller is configured to receive pressure data from the at least one pressure sensor and to determine optimal timing for dosing of the vehicle exhaust component based on the pressure data.

Methods and systems are provided for adjusting a location of a fuel injection in response to a substitution rate and a desired EGR flow. In one example, a method may include injecting a first fuel to a combustion chamber via a direct injector positioned to inject directly into the combustion chamber, injecting a second, different, fuel to the combustion chamber via an exhaust port injector positioned to inject toward an exhaust valve of the combustion chamber, and combusting the first and second fuels together in the combustion chamber.