| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control system, which includes an exhaust emission control device in an exhaust passage of an internal combustion engine and supplies fuel to the exhaust emission control device as required, and an exhaust emission control method which allows a rise in temperature of a catalyst in the exhaust emission control device by efficiently supplying secondary air to an exhaust passage at desulfurization treatment and PM regeneration treatment after an engine starts. <P>SOLUTION: In an exhaust emission control device 18 in an exhaust passage 11 of an internal combustion engine 10, air A1 not pressurized and air A2 pressurized by a compressor of a supercharger are selectively supplied to an exhaust passage through the medium of a lead valve 32. When an engine starts, air A1 not pressurized is intermittently supplied to the exhaust emission control device 18 in response to pulsation of exhaust pressure so that oxidation reaction of the fuel in a catalyst is promoted. In desulfurization treatment and PM regeneration treatment, pressurized air A2 is supplied to the exhaust emission control device 18 at a sufficient flow rate to oxidize an abundance of fuel, thereby time of raising temperature is shortened. <P>COPYRIGHT: (C)2010,JPO&INPIT |
