Abstract:
An exhaust treatment system is provided for treatment of an exhaust stream, where the system comprises a first dosage device, arranged to supply a first additive into said exhaust stream and a first reduction catalyst device, arranged downstream for reduction of nitrogen oxides in said exhaust stream through the use of said first additive, and for the generation of heat through at least one exothermal reaction with said exhaust stream. A particulate filter arranged downstream of said first reduction catalyst device to catch soot particles. A second dosage device arranged downstream of said particulate filter to supply a second additive into said exhaust stream and a second reduction catalyst device, arranged downstream of said second dosage device for reduction of nitrogen oxides in said exhaust stream through the use of at least one of said first and said second additive.
Abstract:
An exhaust treatment system is provided for treatment of an exhaust stream, where the system comprises a first dosage device, arranged to supply a first additive into said exhaust stream and a first reduction catalyst device, arranged downstream for reduction of nitrogen oxides in said exhaust stream through the use of said first additive, and for the generation of heat through at least one exothermal reaction with said exhaust stream. A particulate filter arranged downstream of said first reduction catalyst device to catch soot particles. A second dosage device arranged downstream of said particulate filter to supply a second additive into said exhaust stream and a second reduction catalyst device, arranged downstream of said second dosage device for reduction of nitrogen oxides in said exhaust stream through the use of at least one of said first and said second additive.
Abstract:
Provided is an exhaust purification apparatus for an internal combustion engine capable of reducing the quantity of a catalytic noble metal used in a catalytic converter without reducing the purification performance. A catalytic converter unit (3) contains an OSC material in addition to a catalytic noble metal, and includes an upstream catalytic converter (31) and a downstream catalytic converter (32) provided on the downstream side of the upstream catalytic converter (31). The upstream catalytic converter 31 contains more OSC material than the downstream catalytic converter (32), and the downstream catalytic converter contains more catalytic noble metal than the upstream catalytic converter (31). The exhaust purification apparatus (2) is equipped with an LAF sensor (61), an oxygen concentration sensor (62), and an ECU (5) that adjusts the air-fuel ratio of the engine (1) based on signals (KACT, V02) output from the oxygen concentration sensor (62) and the LAF sensor (61) such that the air-fuel ratio of the exhaust flowing into the downstream catalytic converter (32) matches a target value set in the vicinity of a theoretic air-fuel ratio.
Abstract:
A system includes a controller (24) programmed to monitor an NH 3 storage state of a selective catalytic reduction (SCR) catalyst (14). The controller is programmed to receive signals representative of NH 3 and/or NO X concentrations in a fluid both upstream of an inlet (18) and downstream of an outlet (20) of the SCR catalyst (14), to receive a signal representative of the measured NH 3 storage of the SCR catalyst from at least one RF probe (38) disposed within the SCR catalyst, to utilize a model to generate an estimated NH 3 storage of the SCR catalyst based at least on the NH 3 and/or NO X concentrations in the fluid both upstream and downstream of the SCR catalyst, to compare the estimated NH 3 storage to the measured NH 3 storage, and to output a control action for the SCR catalyst based on the comparison of the estimated NH 3 storage to the measured NH 3 storage.
Abstract:
An exhaust gas control apparatus includes an exhaust passage (19), a urea water tank (45), a urea adding valve (40), a urea pump (47), a pipe (46), and an electronic control unit (56). The electronic control unit (56) is configured to drive the urea pump (47) as a filling control when a condition requiring an execution of urea water addition by the urea adding valve (40) is satisfied such that the pipe (46) is filled with the urea water. The electronic control unit (56) is configured to execute the filling control when an exhaust pressure of the exhaust passage (19) is equal to or less than a specified value. The electronic control unit (56) is configured to stop the filling control when the exhaust pressure of the exhaust passage (19) exceeds the specified value during the execution of the filling control.
Abstract:
A deterioration diagnosis device for an exhaust gas purification apparatus which performs inducement processing when the internal combustion engine (1) is operated at a lean air fuel ratio, measures, by means of air fuel ratio sensors, the air fuel ratio of exhaust gas flowing into the SCR catalyst (6) and the air fuel ratio of exhaust gas flowing out from the SCR catalyst (6) during a period while the inducement processing is performed, and diagnoses deterioration of the SCR catalyst (6) based on a difference between the measured values of these sensors, wherein an amount of hydrogen produced by each of a three-way catalyst and an NSR catalyst (5) is estimated based on the deterioration degree thereof, and an air fuel ratio of exhaust gas discharged from the internal combustion engine is feedback-controlled so that the air fuel ratio of the exhaust gas flowing into one of the three-way catalyst and the NSR catalyst (5) in which the hydrogen production amount thus estimated is larger than that in the other becomes a target value.
Abstract:
An exhaust gas purification apparatus of an internal combustion engine includes: an NH 3 generating catalyst which generates NH 3 from NOx and H 2 at a rich air-fuel ratio; an in-cylinder injection valve which injects fuel into a cylinder; and a control apparatus which, when setting a rich air-fuel ratio, sets a timing of fuel injection from the in-cylinder injection valve to a second half of a compression stroke when a temperature of the NH 3 generating catalyst is within a first prescribed range and sets a timing f of fuel injection from the in-cylinder injection valve to a first half of an intake stroke when the temperature of the NH 3 generating catalyst is within a second prescribed range that is a higher temperature range than the first prescribed range.