| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control device in an internal combustion engine which can reduce an ammonia slip. <P>SOLUTION: An exhaust emission control device 10 in an internal combustion engine which is composed of an exhaust path 19 making exhaust gas discharged from an engine 11 to circulate therethrough, a SCR catalyst 22 provided at the exhaust path 19, an urea water adding valve 25 serving as an urea water adding means for adding urea water to the exhaust path 19 in an upstream to the SCR catalyst 22, and a control device 30 controlling an adding amount of the urea water added to the exhaust path 19 through the urea water adding valve 25 at fixed time intervals and acquiring an amount converted into ammonia from an adsorption substance adsorbed to the SCR catalyst 22 by adding urea water until a fixed time period elapses after the control of the adding amount of urea water on the basis of a temperature of the SCR catalyst 22, controls the adding amount of urea water injected into the exhaust path 19 through the urea water adding valve 25 on the basis of the amount converted into ammonia from the adsorption substance estimated by the control device 30. <P>COPYRIGHT: (C)2011,JPO&INPIT |
