Bypass controlled regeneration of NOx adsorbers

摘要

In a method and apparatus for regenerating a lean NOx adsorber, the NOx adsorber treats exhaust gases created during the combustion of gaseous fuels in general. A bypass line maintains a target regeneration flow of exhaust gas through the NOx adsorber during regeneration regardless of operating demands on the engine. Closed-loop and open-loop control are employed. The closed-loop control employs sensors that determine properties of the exhaust gas during regeneration, and the controller uses those properties to provide an efficient regeneration cycle. A regeneration map is also provided that uses creation of in-cylinder regeneration conditions for the exhaust gas in combination with in-line regeneration conditions for the exhaust gas.