Control strategy for main steam pressure of combustion system of pulverized coal boiler

Boiler combustion system is a complicated large delay system. The heat of the coal in steam boiler system is mainly reflected in steam flows. In this paper, a well-performed coal-fed plan is presented for the direct blow pulverized coal-fired boiler according to the conditions of fan mills. Moreover, the caloric value of coal is estimated and acts as the feedback signals of the inner loop; thus, the cascade PID control scheme is carried out for the main steam pressure control. This control strategy has been used in a power plant. The actual operation shows that the main steam pressure can be controlled within the desired scope. The system is running steadily and reliably, and good performance has been achieved.