| 摘要 |
PURPOSE:To maintain an NOX value, by a method wherein, based on the result of comparison of unburnt content (UBC) in ash, produced from an estimated program, with a set UBC, a rise in the air ratio of a burner at each stge, atomization of pulverized coal particles, and carbonization in the low fuel ratio of coal used are effected in order by application of load. CONSTITUTION:The estimated value of a UBC is calculated by a UBC calculating computer 7, and the signal thereof is fed to a UBC setter 8 to compare it with a desired UBC set value. If the estimated value of the UBC exceeds the set value, dampers of air feed branch pipes leading to an air box 6 are opened, in order, from the lower one to the upper one to increase an air ratio. Thereafter, based on a signal sent from a mill condition setter 9, the opening of the vane of a mill 15, a load and a classifier are automatically regulated to gradually decrease the particle size of pulverized coal. Further, in response to a signal sent from a coal selector 10, coal fed to a mill 11 is gradually shifted to a low fuel ratio coal. This enables an unburnt content in ash to be kept at a low level as NOX is maintained at lower than a regulated value.
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