Patent ID: 8511070
Filing Date: 2013-08-20
Classification: F01N,F02D,Y02T

Abstract:
1. An exhaust purification system for an internal combustion engine, the exhaust purification system comprising: an exhaust passage; a storage-reduction NOx catalyst that is provided in the exhaust passage through which exhaust gas from the internal combustion engine passes and that purifies NOx in the exhaust gas; a fuel addition valve that supplies fuel into the exhaust gas aside from the fuel for burning in a cylinder of the internal combustion engine; and an electronic control unit that includes control logic, which when executed: the rich burn and the lean burn are executed alternately, when a SOx regeneration treatment of the storage-reduction NOx catalyst is executed, such that a rich atmosphere of the storage-reduction NOx catalyst that enables release and reduction of SOx is achieved during a rich period in which the rich burn is executed and a temperature of the storage-reduction NOx catalyst, during the rich period and a lean period in which the lean burn is executed, is maintained at a temperature that enables the release and reduction of the SOx by supplying the fuel into the exhaust gas with the fuel addition valve during the lean period and the rich atmosphere of the storage-reduction NOx catalyst that enables the release and reduction of the SOx is also maintained during the lean period by the fuel supplied into the exhaust gas by the fuel addition valve.