Patent ID: 8748187

Claim:
A control system for a NOx removal device, wherein the NOx removal device comprises: reagent introducing means for introducing a reducing agent into exhaust gas which is discharged from a boiler and flowing inside a duct, the reducing agent for reducing NOx in the exhaust gas, and a NOx removing portion which has a catalyst and removes NOx from the exhaust gas into which the reducing agent has been introduced, and the control system for the NOx removal device comprises: a temperature measuring device that measures a temperature distribution of the exhaust gas inside the duct, the reducing agent having been introduced into the exhaust gas; a reagent-concentration calculating portion that calculates a concentration distribution of the reducing agent introduced into the exhaust gas based on the temperature distribution determined at the temperature measuring device; a reagent-flow-rate determining portion that determines a desired flow rate of the reducing agent to be introduced into the exhaust gas by the reagent introducing means in accordance with the concentration distribution calculated at the reagent-concentration calculating portion when the concentration distribution does not reach a desired concentration distribution; and a reagent-introducing-means control portion that controls the reagent introducing means so as to introduce the reducing agent into the exhaust gas at the desired flow rate determined at the reagent-flow-rate determining portion.