Method for controlling injection of urea into exhaust gas tract of motor vehicle, involves setting desired level of content of urea solution in gas tract, and supplying urea solution into tract if actual level is lesser than desired level

摘要

The method involves setting a desired level of a content of an aqueous urea solution in an exhaust gas tract (S1) after a cold start of a motor vehicle and before increasing exhaust gas temperature in the exhaust gas tract to evaporate the urea solution. Operating parameters e.g. exhaust gas temperature and exhaust gas mass flow rate, are measured (S2), and an actual level of the content of the aqueous urea solution in the exhaust gas tract is calculated (S3). The urea solution is supplied (S5) into the exhaust gas tract if the actual level is lesser than the desired level. Independent claims are also included for the following: (1) a controller for an urea injection device (2) a computer readable storage medium comprising a set of instructions for executing a method for controlling injection of urea into exhaust gas tract arranged upstream to an selective catalytic reduction (SCR) of a motor vehicle.