Circulating fluidized bed boiler is a specific type of boilers, and compared with the other boilers, it has certain advantages, which are: it has great improvement in combustion technology, which can improve the boiler combustion quality and combustion effect, and in turn, to improve the boiler effect. This is achieved because two return feeders are used in this type of boiler to allow the fuel to form a circulation loop between the furnace and the return feeder.
1. Primary air fan: after being heated by the air pre-heater, primary air enters into the wind chamber, then into the furnace through wind caps through the air distributor to fluidize particulate materials;2. Secondary air fan: after being heated by the air pre-heater, secondary air enters into the furnace through the secondary air ducts for complete combustion of fuels; the seal air, conveying air and fuel spreading air of the feeding device also adopt secondary air; 3. Circ...
The bed temperature rises sharply.
Oxygen levels go down and sometimes drop to zero.
The electric current of primary air fan is less and wind pressure of air compartment is higher.
Negative pressure of furnace is increased while the electric current of induced draft fan is reduced.
The slag discharge is difficult or unsuccessful.
When appearing bed clinkering, the bed temperature and bed pressure will be uneven distributed and not at normal condition; the measuring point of part bed tempe...
(Question Details) Specific Performance:The pipe of superheater bursts in circulating fluidized bed boiler operation.The bed pressure indicator fluctuates little. Answer: causes of failure:(1) Design Factors.(2) Manufacturing process, installation and maintenance quality.(3) The temperature control device is unreasonable or does not work properly.(4) Effect of operating conditions on overheating and explosion of superheater. Troubleshooting:(1) Report the fact to operator on duty and require operating the boiler in low load.(2) When the overheat damage is serious,please report it to operator on duty and require stoping the boiler immediately to prevent blowout of the near pipes.(3) Adjust the steam temperature as much as possible within the normal range.(4) If the superheater tube is not damaged badly, it has little effect on the temperature level of the steam, and it can be allowed to run in a low load range for a short period of time.
(Question Details) Specific Performance:(1) The bed temperature has risen sharply.(2) The oxygen level drops even to zero.(3) The current of the primary blower is reduced, and the wind pressure in the wind chamber is high and fluctuates.(4) The furnace negative pressure increases and the induced draft fan current decreases.(5) Difficulties in slagging.(6) If coking in low temperature, the bed temperature, bed pressure distribution is uneven, the deviation is too large, the bed pressure, the plenum pressure, the bed temperature is not normal, and the local bed temperature measurement point is not normally raised or lowered.(7) The bed pressure indicator value fluctuates little. Answer: causes of failure :(1) Improper operation, resulting in overheated bed temperature and coking.(2) The primary air volume during operation is kept too small, which is lower than the minimum fluidized air volume, so that the material can’t be well fluidized but piled up, the temperature field of the entire
(Details on the problem) Specific Performance:Slagging pipe blocks during operation of circulating fluidized bed boiler. Answer：cause of failure:(1) The internal shape is caused by the limited expansion of the wear-resistant material inside the slag discharge pipe. The internal components of the slag cooler are deformed, affecting the fluidization of the slag cooler; the slag cooler is deactivated for a long time or a single slag cooler is selected for slagging, and the bed material in the deactivated slag cooler is bonded under the influence of steam, which being low temperature coke.(2) The operating personnel did not grasp the ratio of the fluidized air volume of the slag cooler. Inappropriate air volume ratio resulted in poor ash slag fluidization in the slag cooler. Troubleshooting:(1) Operation personnel should strengthen understanding of boiler operating conditions, adjust boiler parameters in a timely manner, set up the concept of boiler material dynamic balance, control boiler
(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
(Question Details) Specific Performance:Broken coal is one of the most common failures of the coal feeder. The coal feeder is the lifeline of the boiler. Its normal operation is the basic guarantee for the normal and stable operation of the boiler, because it’s common occurrence that the coal feeder breaks the coal, especially when multiple coal feeders broken coal simultaneously, the improper handling resulting in overheating, explosion, coking, shutdown and other failures. Answer：cause of failure:(1) The particles of fluidized bed boiler fuel are coarse, but the fine particles in the fuel have a large amount of moisture. It is very easy to bond, resulting in the clogging of coal bunker and coal feeder.(2) Coal particles are jammed and squeezed in the coal feeder, causing the coal feeder chain to break.(3) Impurities in coal, such as woven bags and tree blocks, enter the coal feeder, causing coal feeders to jam, blockage, trip and break pins. Troubleshooting:(1) Fluidized Be
