| 摘要 |
<p>PURPOSE: To maintain NOx concentration at the outlet of a denitration facility close to a set value by correcting the injection of a reducing agent the basis of the rate of change in load requirement of a combustion apparatus and the rate of change in NOx concentration at the outlet of the denitration facility. CONSTITUTION: The amount of ammonia to be injected is determined from a signal 13 of an ammonia molar ratio necessary to obtain the rate of denitration which is necessary to maintain NOx concentration at the outlet of a denitration facility at a set value, a signal 15 of a feedback correction molar ratio by the output signal of an outlet NOx concent,ration meter 4, a signal 33 of ammonia injection correction by a fuzzy controller 30, and a signal 32 of a dynamic previous value to a signal 5 of load requirement. In this way, the delay of denitration reaction is compensated by dynamic previous control in response to the rate of change in load to the generation of a peak value in NOx concentration at the time of load variation in a coal burning plant, and the shortage of ammonia due to dynamic previous control is compensated by fuzzy control based on the rate of change in load and the rate of change in outlet NOx concentration. Therefore, even at the time of high speed load variation, the outlet NOx concentration is made close to a set value.</p> |
