1. If one induced draft fan is found to trip in emergency, and the forced draft blower is tripped in succession, the outlet baffle of the induced draft fan shall be checked and the baffle of the forced fan outlet baffle shall be closed in succession. Total capacity of the forced draft blower >25% shall be checked to maintain stable negative pressure, and when the air  capacity shall be increased to over 40% of the total capacity, the forced draft blower tripped in succession can be started in order to meet the requirement of the air capacity, and it load shall be reduced to 180MW rapidly. If three mills are operating, one mill trips due to action of RB, in the mean time the superheater, reheater temperature and boiler drum water level shall be monitored strictly.
2. If it has been checked that the flame is stable relatively and the negative pressure fluctuation is within 500kPa, it can be considered to use 23 oil guns for stabilizing combustion.
3. If the unit is under the coordinating control mode, RB acts and makes Mill C trip in succession, and the load shedding is quickly up to 200MW below, after the emergency happens, the coordinating control system can be manually relieved to quickly reduce the load, the operation is as the above mentioned.
4. If the flame detection is lost mostly and the flame can not be monitored, the combustion is not stable, then MFT can be manually operated. If the negative pressure reaches to +1600Pa or the boiler drum water level reaches to the shutdown value of boiler, the treatment shall be done according to that the boiler fire is extinguished.