METHOD AND DEVICE FOR CONTROLLED ADDITION OF RESTORING AGENT IN THE EXHAUST GAS OF A VEHICLE ENGINE CONTAINING NITROGEN OXIDES

摘要

Process for controlled addition of a reducing agent into nitrogen oxides containing exhaust gas being contacted with a selective reducing catalyst for abatement of the nitrogen oxides by reaction with the reducing agent in contact with the catalyst, comprising the steps of determining mass flow of combustion air passed to the engine; determining concentration of nitrogen oxides in the exhaust gas prior to contact with the catalyst; determining temperature of the exhaust gas at inlet of the catalyst; determining temperature of the exhaust gas at outlet of the catalyst; and communicating determined values of the air mass flow, the nitrogen oxides concentration and the inlet and outlet temperature to an electronic control unit using a serial interface and calculating amount of reducing agent to be injected into the exhaust gas prior to contact with the catalyst.