EXHAUST GAS PURIFYING DEVICE AND METHOD FOR INTERNAL COMBUSTION ENGINE

摘要

Removal of fine particles by oxidation or/and sulfur poisoning recovery control may be required when an internal combustion engine has been in an extremely low load state for a predetermined period or more. In this case, the engine speed of the internal combustion engine (I) is adjusted to a range where the temperature of a filter (20) can be raised by heat-up control. The heat- up control is then executed by. a filter temperature control means to raise the temperature of the filter (20) to a predetermined value. When the filter (20) reaches the predetermined temperature by means of low- temperature combustion, post-injection, VIGOM-injection, addition of 10 fuel to an exhaust system and the like, removal of fine particles by oxidation or/and sulfur poisoning recovery control for eliminating sulfur poisoning of a NOx absorbent are conducted. Removal of PMs captured by the filter and sulfur poisoning recovery control of the NOx absorbent can thus be conducted even if the internal combustion engine is left in an extremely low load operational state.