Abstract: A compact SCR device is provided for use with a diesel exhaust fluid (DEF) injection system having multiple injectors for providing diesel exhaust fluid to exhaust gas to reduce NOx emissions. The DEF injectors are disposed in the close coupled SCR mixer. A first injector injects into a chamber of the mixer with sidewardly oriented impingement plates having openings. A second injector radially spaced and offset has a different angle from the first injector for injecting DEF into the SCR mixer. A swirl plate forces the exhaust gas in the flow path to turn and exit through an outlet opening. An inlet opening for the mixer is aligned transversely near the first injector and is offset from the outlet opening. Thus, upon entering the compact SCR mixer, the exhaust gas must change direction and passes by at least one injector and impingement plates having flaps and openings before exiting the mixer.

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 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.

Abstract: A compact SCR device is provided for use with a diesel exhaust fluid (DEF) injection system having multiple injectors for providing diesel exhaust fluid to exhaust gas to reduce NOx emissions. The DEF injectors are disposed in the close coupled SCR mixer. A first injector injects into a chamber of the mixer with sidewardly oriented impingement plates having openings. A second injector radially spaced and offset has a different angle from the first injector for injecting DEF into the SCR mixer. A swirl plate forces the exhaust gas in the flow path to turn and exit through an outlet opening. An inlet opening for the mixer is aligned transversely near the first injector and is offset from the outlet opening. Thus, upon entering the compact SCR mixer, the exhaust gas must change direction and passes by at least one injector and impingement plates having flaps and openings before exiting the mixer.

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.

Abstract: A diagnostic for an internal combustion engine exhaust gas treatment means includes a series of enabling conditions for modelling temperature and operational stability of the treatment means and includes first and second stage tests alternately applied on an engine air/fuel ratio cycle-by-cycle basis in accord with the diagnosed performance of the treatment means using post-converter oxygen sensor information. When the treatment means performance is diagnosed as being degraded close to a failed condition, the first stage is disabled and the more statistically rigorous second stage is activated to closely scrutinize converter performance using a two phase approach for false alarm protection.