| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To enable proper control of an addition amount of a reducing agent by estimating an adsorption amount of a reducing agent to a NOx reduction catalyst. <P>SOLUTION: In a method for controlling an exhaust emission control device where an NOx reduction catalyst 10 is situated in the middle of an exhaust pipe 9, and urea water 17 (the reducing agent) is added on the upper stream side of the NOx reduction catalyst 10 by a urea water adding means 18, and NOx is reduced and purified, an NOx generating amount is estimated and an addition amount of the urea water 17 corresponding to the estimated value is decided. Meanwhile, an NOx reduction amount is estimated and an ammonia consumption amount corresponding to the estimated value is decided. By reducing an integrated value of a consumption amount from an integrated value of an addition amount of the urea water 17, an adsorption amount of ammonia to the NOx reduction catalyst 10 is estimated. A correction factor corresponding to the adsorption amount is decided and an addition amount of the urea water 17 is corrected by the correction factor, and the corrected addition amount of the urea water 17 is set as an addition indicating value to the urea water adding means 18. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
