(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
Question details (Performance):The steam pipe vibrates violently and has a dull impact sound.Answer: fault reason: There is air in pipeline ; automatic air vent valve is not turned on; or it is out of order. Troubleshooting: Check all the air release valves on the water supply pipe and the air release valves on the top of the boiler tube for gas storage. If the valve fails, it should be replaced immediately.
Question details (Performance):1. High temperature of motor, fast temperature rise.2. Overload, high outlet pressure and frequent safety valve open often.3. The vibration is intensified, the side vibration of the fan motor coupling is large, and the fan body never vibrates to vibration.4. No obvious vibration was found in no-load test of fan motor. Answer: Fault reason:Fan bearing vibration is common fault in the operation, the vibration of the fan will cause damage of bearing and blade, bolt looseness, chassis and wind damage, fan vibration rises abruptly in the operation. this is because when the gas enter impeller and the rotating blade working face has certain angle, according to the principle of fluid mechanics, gas from non-working face must be a spiral blade, so the dust particles in the gas will slowly sedimentation due to vortex. Airfoil blades are very easy to accumulate dust. When the accumulated ash reaches a certain weight, a part of the large amount of accumulated ash wi
Question details (Performance):1. The furnace wall at the coal economizer leaks water and steam with abnormal sound.2. The water level in the boiler drops sharply, and the water supply is obviously greater than the evaporation capacity.3. Smoke exhaust temperature and water outlet temperature rise.Answer: Fault reason:1. The water quality does not reach standard, and the oxygen in the water is decomposed into corroded pipe walls when the temperature rises.2. The low feed water temperature and smoke exhaust temperature make the inner and outer wall of the coal economizer pipe produce acid corrosion, or flying ash wear the pipe wall thin. 3. The pipe is blocked by impurities, causing overheating.4. Poor materials, defects in manufacturing, installation and maintenance. Troubleshooting:1. When economizer is slightly broke, it still maintains boiler operation, and the gap seems will not expand rapidly, in this case, load operation should be reduced, and start the spare boiler immediately,
(Question details) Specific performance:The wall thickness of several boiler tubes was significantly reduced in a large area, the remaining wall thickness was 2.0mm, and some furnace tubes were corroded and worn out. Furnace tube wall is covered with a thick layer of uneven scale, the surface of the scale is brick red and black, scale layer is loose, and it is easy to remove the inner wall of the furnace tube, after removing, the furnace tube wall covered with a layer of corrosion pits. There is a thin layer of brick red corrosion on the outer wall of boiler tube, some of which are attached with black adhesive. Answer: Fault reason:1. The boiler is seriously short of water.2. Poor water circulation and uneven combustion.3. The unqualified quality of the boiler water and undemanding chemical supervision make the inner wall of the pipe corrode and scale, causing the pipe overheat and reduction of the strength.4. Due to the presence of impurities and scale, the furnace tube is blocked ins
