Def Injection Strategy for Multiple Injection Systems

Abstract

A diesel exhaust system includes multiple injectors for providing diesel exhaust fluid to an exhaust to reduce NOx emissions. Two or more injectors provide DEF to the exhaust system of an engine. In one mode, the injectors alternately inject DEF fluid. In one embodiment, the system includes a NOx sensor or a NOx model to assist in determining an amount of DEF that must In be provided. In a high DEF output operating mode, the DEF amount for one injector is output at a higher rate than the other injector such that deposits may form. After the injector at the higher rate of injection operates for a selected fraction of time, the other injector provides DEF fluid at the higher rate. Further, the system calculates an estimated developed liquid film mass for each injector output. When the estimated developed liquid film mass is not less than a parameter limit film mass, the system performs ATS regeneration.

Dependencies are inferred from the claim text.