Introduction: Circulating fluidized bed boiler technology is a highly efficient and low-pollution clean combustion technique developed rapidly in recent ten years. Internationally, this technology has been widely used commercially in the fields of power station boilers, industrial boilers and waste treatment and utilization, and has been developed to large-scale circulating fluidized bed boilers with the scale of several hundred thousand kilowatts. The domestic research and development in this area And applications are also gradually emerging, hundreds of circulating fluidized bed boilers have been put into operation or are being manufactured. The next few years will be a rapid development of circulating fluidized bed an important period. I. Overview Circulating fluidized bed boilers have the advantages of good adaptability to fuels and low emission of harmful gases, and have been rapidly developed in China in recent years. Many large circulating fluidized bed boiler units in our country have been put into operation one after another. Because the circulating fluidized bed boiler combustion technology is not mature enough and the manufacturing process is not advanced enough, there are many problems in operation. Among them, the slag cooler, as an important part of the safe and efficient operation of a circulating fluidized bed boiler, is one of the major causes of forced shutdown and load shedding. The high temperature ash discharged from the circulating fluidized bed boiler takes away a large amount of physical heat, resulting in a large amount of slagging heat loss, lowering the boiler efficiency, deteriorating the on-site operating conditions, residual sulfur and nitrogen in ash Can still release sulfur dioxide and nitrogen oxides outside the furnace, resulting in environmental pollution. On the other hand, the handling and transportation of hot ash is troublesome. Therefore, ash cooling is very necessary. In addition, there are also many incompletely reacted fuel and desulfurizer particles in the bottom slag. To further improve the efficiency of combustion and desulfurization, it is necessary to return this part of the fine particles to the hearth. These operations are also performed in the cold slag unit. Now many slag cooler comprehensive utilization of a variety of flow and heat transfer methods, the advantages of various slag cooler together to make it more and more high performance, adaptability getting better. In recent years, large-scale circulating fluidized bed boiler? Plum plum? Second, Feng Shui joint slag cooler common fault analysis Feng Shui combined slag cooler without moving parts, completely solve the most common mechanical failure, while its strong ability of cold slag, to adapt to a wide range of boiler unit thermal efficiency and utilization of units can be improved, but the operation also found many problems, the main (3) hot air pipeline blockage, which is because the entrained fine ash can not be effectively separated. (2) the capacity of handling large pieces of slag is not enough, (4) bed Qg buried tube wear, due to slag slag processing slag screening, so the fluidized air velocity can not be as low as the external heat exchanger, as (5) the design of the air supply system is insufficient, resulting in adjustment difficulties; (6) the performance of the slag cooler needs to be improved. The following on the feng shui common operation of slag cooler in the common causes of failure and processing methods further analysis, I hope some help to the operating staff. 1. Slag into the slag tube clogging phenomenon: Slag into the slag tube temperature decreases; slag cooler room temperature decreases; fluctuating wind volume changes, the choice of room temperature, no change in bed pressure. Analysis of the reasons: the lack of fluidized air flow rate during low load operation, resulting in furnace Qg slag block; hood plugs blocked plugging; falling refractory slag tube off; slag cooler? W phase outages, into the slag tube progressive Constipation clogged. Handling methods and precautions: 1.1 Close observation of slag cooler into the slag temperature and slag cooler room temperature, bed pressure, appropriate to increase the pulsating air volume. 1.2 If the treatment is invalid, the pulse damper should be closed, turn on the purge air purge door, and gradually open the big purge door for intermittent purge. When the temperature of the slag pipe and the temperature of the slag selector, bed pressure and other parameters begin to change, Indicating slag cooler has begun to enter the slag, then immediately reduce or maintain the purge door opening, shut down after normal compressed air purge door, slowly open into the slag duct for air throttle control slag cooler bed pressure in the normal Range Qg. 1.3 running as much as possible put into operation a number of slag cooler, each slag slag slag control at a lower level and continuous operation, so to avoid slag clogging blockage. 1.4 Slag should be shut down slag discharge damper, electric door closed to prevent coking blockage into the slag. 2. slag cooler selection room coking, clogging phenomenon: slag cooler room temperature selection, bed pressure is not normal, or even exceed the hearth temperature; room after the selection of the room temperature is low; to stop the slag, after blowing After the furnace shutdown, it was found that the selection chamber Qg knot n? Clinker, and contains more carbon particles, slag layer is obviously stratified, is a low temperature coke; slag cooler selection room has a lot of coke Piece. Analysis of reasons: Coal has strong coke; Coal is too poor, too much coal gangue and debris, resulting in excessive slagging; fine crusher damage, resulting in coal particle size is too large, difficult to be fluidized by the wind; due to operational adjustments Improper, the formation of the furnace Qg coking, coke block into the slag separator selection room; selection chamber hood plug, or select the room fluidized air flow is low, resulting in selection chamber Qg bed material can not be timely row \ ?, low temperature bonding; Due to the slag temperature close to the hearth of the hearth, there is a lot of air in the selection chamber Qg, and the carbon particles rapidly burn down. As a result, Resulting in clogging of the selection chamber; boiler slagging uncontrollably, a large number of unburned coal particles with slag flow into the slag cooler selection chamber in the thick layer of the slag layer will cause local ditch and local Of the non-fluidized, and in the selection chamber Qg combustibles re-combustion and coking, resulting in the selective chamber slag mouth blockage. 1. Slag into the slag tube blocked Phenomenon: Slag into the slag tube temperature decreases; slag cooler room temperature decreases; fluctuating wind air volume changes, the choice of room temperature, no change in bed pressure. Analysis of the reasons: the lack of fluidized air flow rate during low load operation, resulting in furnace Qg slag blocks; falling hood at the hood cap plugging; slag falling refractory material fall off; slag cooler? W phase outages, into the slag tube progressive Constipation clogged. Processing methods and precautions:
