| 摘要 |
PURPOSE:To prevent the injection of excessive NH3 by avoiding a temporary sudden increase in the concn. of NOx at the outlet of a denitrizer and keeping the denitration efficiency corresponding to a set mol ratio. CONSTITUTION:A denitration control device is equipped with an NOx concn. estimating means 11 estimating the concn. of NOx at the inlet of a denitrizer, an inlet NOx concn. correcting means 12 determining the correction signal of the concn. of NOx at the inlet of the denitrizer from the estimated concn. of NOx, an exhaust gas flow rate estimating means 13 estimating the flow rate of exhaust gas from the flow rate of fuel, an NOx injection reference amt. determining means 14 calculating an NH3 injection reference value from a denitrizer inlet NOx total amt. calculated value being the product of the concn. of NOx at the inlet of the denitrizer and the exhaust gas flow rate estimated value, a load differential value and a mol ratio, a denitrizer outlet concn. estimating means 15 estimating the concns. of NOx and NH3 at the outlet of the denitrizer and an NH3 injection correction amt. determining means 16 determining the correction amt. of an NH3 injection amt. from the estimated concns of NOx and NH3 and the NH3 injection reference value. |
