Southwest Research Institute

Vlad L C Ulmet

Magdi K Khair

Gary Dale Neely

Stefan Simescu

Chad P Koci

A method for controlling emissions in the exhaust gas of a diesel engine, the engine having an exhaust gas recirculation (EGR) system. The engine's exhaust aftertreatment system need have only an oxidation catalyst and a particulate filter (with no NOx reduction or adsorption device). In 'normal' engine conditions, the engine is operated with a lean air-fuel ratio, with 'normal' engine conditions being engine conditions other than transient load increase engine conditions. Also, during normal engine conditions, the EGR system is used to reduce engine-out NOx. During transient load increase engine conditions, the engine is operated stoichiometrically or near stoichiometrically and the use of EGR is interrupted.

Diesel engine operation for fast transient response and low emissions

A method of reducing emissions by operating a diesel engine in a stoichiometric air-fuel ratio mode. To achieve an optimal stoichiometric mode, intake throttling, boost air intake control, fuel injection adjustments, and exhaust gas recirculation (EGR) are used. This mode of operation permits an aftertreatment system that has only an oxidation catalyst and a particulate filter.

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San Antonio, TX, United States of America

Vlad L C Ulmet