| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control method and an exhaust emission control system capable of preventing white smoke from flowing out by surely oxidizing an unburned fuel fed into exhaust gases regardless of the operating conditions of an internal combustion engine in the regenerative control in which a DPF is heated by oxidizing the unburned fuel fed into the exhaust gases by an oxidation catalyst when the DPF is forcibly regenerated. <P>SOLUTION: In an exhaust emission control system 1, the DPF 12b is controllably heated by feeding the unburned fuel to the upstream side to an oxidation catalyst and oxidizing it, the minimum value Qumin of a first upper limit value Qu1 obtained by deducting a fuel injection amount Qe for cylinder combustion from a first flammable fuel amount Qa1 limited by an air-fuel ratio, a second upper limit value Qu2 obtained by deducting the fuel injection amount Qe for the cylinder combustion from a second flammable fuel amount Qa2 limited by the atmosphere, and a third upper limit value Qu3 as a third flammable fuel amount Qa3 oxidizable by the oxidation catalyst limited by catalyst temperature index temperatures Tg1, Tg2 and the rotational speed Ne of the engine is taken as an upper limit value Qu against the supplied amount Qp of the unburned fuel. <P>COPYRIGHT: (C)2007,JPO&INPIT |
