SCR denitration adjustment control method for urea pyrolyzing furnace

The invention discloses an SCR denitration adjustment control method for a urea pyrolyzing furnace, and belongs to the field of thermal automatic control of thermal power plants. The method comprisesthe following steps: a main PID loop adjusts the NOx concentration of an outlet of an SCR reactor and corrects the amount of NOx needing to be removed, an auxiliary PID loop adjusts the urea solutionamount of each small spray gun, and an adjusting door performing feedforward action on each small spray gun is added to the auxiliary PID loop. According to the SCR denitration adjustment control method for the urea pyrolyzing furnace, a feedforward control signal can be provided in time when the load of a unit rises and falls and a coal mill is started and stopped, and the ammonia injection amount is adjusted; in the purging process of CEMS at the outlet of the SCR reactor and after purging is finished, the NOx concentration at the outlet of the SCR reactor can be automatically adjusted, continuous input can be realiz