To provide an exhaust emission control device of an internal combustion engine and an exhaust emission control method for an internal combustion engine capable of efficiently removing NOx in the exhaust gases.
This exhaust emission control device of the internal combustion engine comprises an oxidation catalyst and an SCR catalyst disposed on the downstream side of the oxidation catalyst, is installed in the exhaust passage of the internal combustion engine, and removes NOx in the exhaust gases discharged from the internal combustion engine. The exhaust emission control device comprises two NOx sensors disposed in the exhaust passage, a calculation means for calculating the concentrations of NO and NO2 in the exhaust gases flowing to the SCR catalyst from the value of the concentration of NOx measured by the two NOx sensors on the basis of the sensitivities of the two NOx sensors to NO2 calculated beforehand, a setting means for setting the flow or flow passage of the exhaust gases passing the oxidation catalyst correspondingly to the ratio of the calculated concentrations of NO to NO2, and a switching means for changing the flow or flow passage on the basis of signals from the setting means.
MIYAMOTO TAKESHI
KUROKI FUMIHIRO
YOKOTA YASUO
FURUYA YUJI
SUMIYA YOHEI
TANIOKA KENICHI
SUGIMURA TAKEHIRO
Seigo Matsuo
Motoyama dare