| 摘要 |
PROBLEM TO BE SOLVED: To provide an exhaust emission control device of an internal combustion engine capable of surely reducing and purifying NOx.SOLUTION: An exhaust gas is introduced into intake air (S10) by operating one or both of EGR valves, injection of urea water is started from an urea water injector when an exhaust gas temperature between the urea water injector and an ammonia adsorption catalyst is within a prescribed temperature range (S12), and an ammonia adsorption amount Wn adsorbed in the ammonia adsorption catalyst is less than a prescribed amount (S14), and ammonia generated in hydrolysis of the urea water is adsorbed by the ammonia adsorption catalyst (S16). The injection of urea water is terminated (S18) in any of a case when the EGR is not introduced, a case when the exhaust gas temperature is outside of the prescribed range, and a case when the ammonia adsorption amount Wn is the prescribed amount or more. |
