Control method of 600 MW subcritical tangentially fired boiler

• Main Authors: LI DEBO, XU QISHENG, LIU YAMING, WEN ZHIYONG
• Format: Patent
• Language: English
• Published: 16.09.2015
• Subjects: BLASTING; HEATING; LIGHTING; MECHANICAL ENGINEERING; METHODS OF STEAM GENERATION; STEAM BOILERS; STEAM GENERATION; WEAPONS

The invention relates to a control method of a 600 MW subcritical tangentially fired boiler. Five coal pulverizers are put into operation with one for standby application. The oxygen content at the coal economizer outlet and total air volume are adjusted. The opening degree of two stages of over-fire air SOFA, each having three layers, is adjusted. The opening degree of two stages of compact over-fire air CCOFA is adjusted. The oscillating angle of a main combustor and differential pressure of a hearth wind box are adjusted. The components in the oxygen content field of the 600 MW subcritical tangentially fired boiler can be effectively adjusted for changing a flame kernel. Therefore, a combustion characteristic of the boiler is changed for decreasing concentration of nitrogen oxide NOX in a coal economizer outlet. On the premise that the concentration of nitrogen oxide NOX in the coal economizer outlet satisfies the requirement for environmental emission, concentration of carbonic oxide CO of an air pre-heater outlet meets the requirement for environmental emission. Heat loss is reduced and heat efficiency is increased. The better control state of the boiler is achieved by seeking for concentration of nitrogen oxide NOX in the coal economizer outlet, carbonic oxide CO of the air pre-heater outlet, carbon content of fly ash, heat loss and heat efficiency and all balance points of all working condition indicators.