To provide a control technique for controlling the injection amount of NH3 in a denitration apparatus so as to be capable of suppressing the concentration of NOX to a target concentration or less by the minimum injection amount of NH3.
The operation region of the nitration apparatus is divided into a first region (I) wherein a molar ratio is less than the molar ratio (KO) of the minimum point minimizing the concentration of NOX and a second region (II) other than the first region and the imaginary concentration of NOX to the molar ratio is set according to an imaginary characteristic curve monotonously changing without being increased with respect to an increase in molar ratio over the range from the first region (I) to the second region (II). Then, feedback control is performed so as to adjust the injection amount of NH3 corresponding to a flow rate of NOX in the direction of allowing the imaginary concentration of NOX to approach the target concentration of NOX (SV) corresponding to the deviation between the target concentration of NOX (SV) and the imaginary concentration of NOX.
KONO SUSUMU
TAKESHITA KAZUKO
IIDA KOZO
ONISHI TOSHIYUKI
HATTORI AKIRA
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