摘要:
A method of dosing a reagent into an exhaust gas stream of an internal combustion engine (3) having an SCR catalyst (13), the method comprising injecting reagent from a reagent tank (21) into the exhaust gas stream at a position upstream of the SCR catalyst (13) using a reagent injector (40) in accordance with a first dosing schedule in order to remediate a predetermined proportion of NOx in the exhaust gas stream, the first dosing schedule being associated with a first range of engine operating conditions; and injecting reagent from the reagent tank (21) into the exhaust gas stream at a position upstream of the SCR catalyst (13) using a reagent injector (40) in accordance with a second dosing schedule in order to enable heat transfer between the reagent injector (40) and said injected reagent, the second dosing schedule being associated with a second range of engine operating conditions. Dosing in accordance with said first or said second dosing schedule is carried out in dependence on whether engine operating conditions lie within said first or said second range of engine operating conditions, and the proportion of NOx in the exhaust gas stream which is remediated by dosing using said second dosing schedule is less than said predetermined portion. A reagent dosing system (1) is also provided for dosing a reagent into the exhaust gas stream of an internal combustion engine (3), comprising a reagent tank (21) for storing a supply of reagent, an injector module (40) comprising an atomising dispenser (42) and a positive-displacement metering pump (41) which draws reagent from the reagent tank (21) and delivers it to the dispenser (42) a supply line (35) coupling the reagent tank (21) to the injector module (40), and a dosing control unit (70) operable to control the injector module (40) to inject reagent into the exhaust gas stream. A priming pump (80) is provided to urge reagent along the supply line (35) toward the injector module (40) under selected conditions.
摘要:
A combined particulate filter and hydrocarbon trap for use in collecting particulate matter and trapping hydrocarbons present in exhaust gas is disclosed. The particulate filter comprises a porous substrate having both inlet and outlet surfaces which are separated from each other by the porous substrate wherein either or both of the inlet and outlet surfaces are coated with a washcoat comprising a hydrocarbon adsorbent material. The hydrocarbon adsorbent material is one or a combination of molecular sieves and the hydrocarbon adsorbent comprises both Ag and Pd, both Ag and Pt or all three of Ag, Pt and Pd.
摘要:
An exhaust purification apparatus for internal combustion engine having a particulate filter disposed downstream of a NOx occlusion reduction catalyst unit and having an S trapping unit disposed upstream of the NOx occlusion reduction catalyst unit. In the apparatus, there is provided first fuel supply means for supplying any additional fuel for regeneration of the particulate filter into the cylinder or exhaust system upstream of the S trapping unit. The additional fuel supplied from the first fuel supply means is regulated to the amount for inhibition of any release of SOx from the S trapping unit. In the apparatus, there is further provided second fuel supply means disposed in the exhaust system between the NOx occlusion reduction catalyst unit and the particulate filter in order to compensate for any deficiency for regeneration of the additional fuel supplied by the first fuel supply means.
摘要:
A combustion engine exhaust after treatment system mount (12), including a body (16), with a first mounting position (18), a second mounting position (20), and a foot (22) for mounting the body to an engine or wall, the first mounting position having a first mounting surface (32), the second mounting position having a second mounting surface (34), the first mounting position having a first longitudinal axis (Ai), and the second mounting position having a second longitudinal axis (A2), the first axis positioned substantially parallel to the second axis. In another aspect a combustion engine exhaust after treatment system is disclosed including such a mount and at least two exhaust gas after treatment components chosen from the group including a particle filter (PF), a muffler, a heat source for PF regeneration, a Selective Catalytic Reductor (SCR) and a mixing chamber, at least one of the components being positioned in the first mounting position and the at least one other component being positioned in the second mounting position, fluidly connected to the first component.
摘要:
Disclosed is an internal combustion engine (12) in which harmful substances contained in the exhaust gas are reduced using a purifying device (22, 24). Said purifying device (22, 24) is at least temporarily regenerated by means of an oxidation process, fresh air being at least temporarily directed straight into the exhaust gas flow upstream of the purifying device (22, 24) by a fan (30) when the purifying device (22, 24) is or is to be regenerated. According to the invention, intake air of the internal combustion engine (12) is used as fresh air, said intake air being compressed and being directed at least in part straight into the exhaust gas flow by a fan (compressor, 30) which is located in the intake zone (16).