To efficiently supply a reducing agent to each exhaust emission control device in an exhaust emission control system of an internal combustion engine equipped with the exhaust emission control devices in series in an exhaust passage of the internal combustion engine.
Exhaust gas flowing from a first branch pipe side (second branch pipe side) containing additional fuel by a first fuel addition valve (second fuel addition valve) to a first merging part (second merging part), and exhaust gas not containing additional fuel and flowing from an exhaust pipe side to the first merging part (second merging part), are merged to thereby stir the additional fuel in the exhaust gas and disperse the additional fuel. Further, by expanding an additional fuel distribution area AHC to a wider range, an additional fuel supply period is increased.
Mayuko Wakuda
Kazunobu Sera
Tsutomu Toyama
Takehiko Sekine
Koichiro Sakai
Fuminori Miyashita