Control for a power plant coal mill pulverizer having feedforward damper positioning

摘要

Power plant boiler fuel demand is transmitted as a coal feeder speed demand to a coal pulverizer control. A speed controller operates the feeder in accordance with the speed demand, and a position controller for a hot coal transport air damper positions the hot air damper to hold the mill outlet temperature to a setpoint value and to increase or decrease damper position in accordance with a feedforward signal representing the feeding speed demand. A position controller for a cold air damper regulates the total primary air flow to a value needed for safe and smooth transport of the pulverized coal to the boiler burners, and it accordingly acts as a process trim on the feedforward control applied by the hot damper controller.