| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control device for an internal combustion engine, in which phosphorus accumulation quantity in NOx purification catalyst can be more precisely estimated, and a process of removal of NOx accumulated in the NOx purification catalyst can be properly performed in accordance with the estimated phosphorus accumulation quantity. <P>SOLUTION: Phosphorus emission flow GPFL which indicates quantity of phosphorus emitted from the engine per unit time is determined in accordance with fuel supply quantity to the engine (S11), and phosphorus accumulation quantity MPAF included in fuel is determined based on the phosphorus emission flow GPFL (S12-S14). Phosphorus accumulation quantity MPOL included in lubricant is determined (S15), and the accumulation quantity MPAF and MPOL are totalled to determine total phosphorus accumulation quantity MPAT (S16). NOx accumulation capacity NOxCAP of the NOx purification catalyst and an NOx reduction ratio correction coefficient KPR are determined in accordance with the total phosphorus quantity MPAT (S17-S19). The NOx accumulation capacity NOxCAP and the reduction ratio correction coefficient KPR are referred to in the NOx removal process. <P>COPYRIGHT: (C)2009,JPO&INPIT |
