| 摘要 |
<p>PURPOSE:To prevent the excess injection of NH3 by actually measuring the inlet side NOx concentration of exhaust gas, calculating the NH3 amount necessary for obtaining the specified denitration efficiency, actually measuring the exit side NOx concentration, comparing the same with the NH3 amount necessary for holding the set value of denitration efficiency and controlling the NH3 injection amount by the lower of these values. CONSTITUTION:The combustion exhaust gas from a generating source 1 is led to a denitration reactor 2 and the respectively measured values of a flowmeter 7, thermometer 8, moisture meter 9 and NOx analyzer 10 are inputted to an operator 11 to calculate the NOx content. The NH3 amount A meeting the specified denitration efficiency with respect to this NOx amount is instructed to a flow controller 12 so that NH3 is supplied from a tank 3. On the other hand, the denitration efficiency is calculated from the actually measured value of the NOx analyzer 13 and when it differs from the set value, the corrected NH3 amount B is inputted to the controller 12 and is compared with A. If a control valve 4 is controlled by the lower of either of these values, the excess injection by the miss-operation of the NOx analyzer may be prevented.</p> |
