Closed loop control method with low nitrogen burning for fire coal boiler

The present invention provides a closed loop control method with low nitrogen burning for a fire coal boiler, which adopts a method for controlling grading air quantity and correcting emission concentration of nitrogen oxide to control the low-nitrogen burning process. The method includes steps as follows: automatically judging the kind of fire coal in the present fire coal boiler according with operation parameters, automatically selecting corresponding functions for setting grading air quantity according with the kind of fire coal and operating method of system equipment, thereby, processingfeedforward control to the low-nitrogen burning process; confirming a setting value of emission concentration of nitrogen oxide by using an optimal model based on economic environmental protection cost, comparing the setting value of emission concentration with a process value of emission concentration, and correcting the setting value of grading air quality according with the compared result, thereby, realizing the feedback control to the low-nitrogen burning process; generally speaking, the method provided by the invention adopts the forecast optimization intelligent feedforward and optimization feedback cascaded adjustment, which can realize the boiler operate economically, environmental-friendly and optimally in condition of changeable environment factors.