(Question Details) Specific Performance:(1) There are blasting sounds in the furnace, and the furnace chamber is under positive pressure. There is smoke emitted from the combustion chamber in a leakage. In severe cases, the explosion-proof door of the boiler body opens.(2) Drum water level drops rapidly and the feedwater flow rate is not abnormally larger than steam flow. MFT acts when the water level is below -280mm.(3) Drum pressure, steam flow rate, exhaust temperature decrease, smoke temperature difference increases on both sides.(4) The negative pressure at the inlet of the flue and suction fan becomes smaller and the temperature difference between the two sides increased. (5) Smoke temperature decreases at the inlet and outlet of the cyclone separator, and the temperature of the material returned is low.(6) Bed pressure increases, bed materials clean, fluidization poof, bed temperature distributes unevenly and bottom slag discharge difficultly. Answer：cause of failure:(1) Fly ash
