| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a control device of an exhaust gas treatment device capable of suppressing consumption of a reducer, effectively reducing a specific component in exhaust gas, and purifying the exhaust gas even while having simple and inexpensive structure. <P>SOLUTION: Unlike the prior art of injecting and adding urea water addition amount suitable for a NOx discharge amount discharged from an internal combustion engine 1 upon starting urea water addition, urea water is injected and added by increasing its amount from a state of urea water adding amount =0 by a first prescribed amount at every predetermined time (S1-S3), a detection signal of an ammonia sensor 8 is observed, when NH<SB>3</SB>flows out to an exhaust gas downstream side of a urea SCR catalyst 5, the urea water addition amount is decreased at every predetermined time (S1, S2, S4, S5), and when NH<SB>3</SB>stops flowing out to the exhaust gas downstream side of the urea SCR catalyst 5, the urea water addition amount at that time is maintained (S5, S6). Therefore, compared to the prior art, NOx in exhaust gas can be reduced and exhaust gas can be purified while suppressing the consumption amount of urea water. <P>COPYRIGHT: (C)2009,JPO&INPIT |
