Patent ID: 8146850

Claim:
A computerized method of controlling a coal mill comprising: receiving, from a coal mill controller that executes on a computer, a target pulverized fuel flow PF t of pulverized coal to a combustion process; receiving a primary airflow rate PA of primary airflow into the coal mill; receiving a coal feed rate CF of coal being fed into the coal mill; receiving differential pressures dP sensed between each of a plurality of sets of two locations within a fuel path of the coal mill, each differential pressure dP sensed with respect to a powder stage of coal within the fuel path of the coal mill; determining a recirculated load RL of coal within the coal mill and a pulverized fuel flow PF a of coal from the coal mill as a function of the differential pressure dP measurements, the primary airflow rate PA, and the coal feed rate CF; estimating a mass of coal powder in each powder stage within the fuel path of the coal mill; and manipulating, through execution of instructions on at least one processor of the computer, CF and PA into the coal mill while receiving differential pressures dP sensed between the plurality of sets of two locations within a fuel path of the coal mill to approximate a pulverized fuel flow PF a to the combustion process, wherein the CF and PA are manipulated to cause the PF a to approach the PF t .