Mill primary air flow controller for pulverized coal fired boiler equipment

摘要

PROBLEM TO BE SOLVED: To provide a mill primary air flow rate control device for pulverized coal burning boiler equipment to enable securing of a heat exchange amount by an air preheater without increasing a flow rate of primary air bypassing an air preheater also when coal less in moisture is fed to a mill, and minimize heat, disposed to the outside of a system by lowering a gas temperature at the outlet of the air preheater, and enable improvement of boiler efficiency. SOLUTION: When the air preheater outlet gas temperature 32 is higher than a set value, a mill inlet primary air temperature 34 is lower than a set value, a mill coal feed amount 19 is higher than a set value, and a mill differential pressure 38 is lower than a set value, a mill primary air flow rate set value 23 based on a mill coal feed amount 19 is set to a low value, and a mill primary air flow rate 17 is reduced.