| 摘要 |
A reagent dosing system for dosing a reagent into the exhaust gas stream of an internal combustion engine 3 comprises 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. The system may further comprise a priming pump (80) operating at start-up, intermittently or continuously during running. The reagent tank 21 may further comprise a tank module 20 mounted within the tank comprising a reservoir closure member 32, pick-up tube 27 and priming pump (80) disposed within the module. A dosing control unit (DCU) may be included which transmits and receive data to/from the injector module and engine control unit (ECU). The DCU and ECU may be integral or connected via a CAN link 77. The application further includes various arrangements of exhaust systems including a particulate filter, oxidation catalyst, lean NOx trap, SCR catalyst and associated dosing units and methods of dosing comprising first and second dosing schedules and drive current level control. |
