METHOD PERTAINING TO AN SCR SYSTEM AND AN SCR SYSTEM

摘要

A method pertaining to an SCR system wherein a reducing agent is provided in an exhaust gas stream from an engine (231) for purifying the exhaust gas with respect to among other things content of NOx. The SCR system comprises a vaporization portion (361) being arranged upstream a catalyst arrangement (260; 262) (s410). The method includes continuously monitoring changes of a temperature (Tmod) of the vaporizing portion, controlling (s420, s430) a mode of operation of the engine (231) based on changes of the temperature (Tmod) of the vaporizing portion, so as to operate the engine (231) based on requirements regarding fuel economy as well as exhaust gas purification and at the same time, avoiding formation of crystals in the vaporizing portion (261). Also a computer program product comprising program code (P) for a computer (200; 210) for implementing a method according to the invention. Also an SCR system and a motor vehicle equipped with the SCR system.