The circulating fluidized bed boiler adopts the fluidized combustion mode, which is between the suspended combustion of pulverized coal furnace and the fixed combustion of chain furnace, that is, the semi-suspended combustion mode. The circulating fluidized bed (CFB) boiler is an internationally recognized clean coal combustion technology, which is gaining popularity in China's coal-fired power stations due to its wide fuel adaptability, good desulfurization effect, low NOx emission and good load regulation performance.
In the circulating fluidized bed boiler, the boiler fuel after crushing and screening and the desulfurizing limestone are sent into the furnace, and the fluidized boiling combustion rises along the furnace under the action of the first and second air, and the heat is transferred to the water wall and the hanging screen in the furnace, and then continues to rise through the furnace outlet into the cyclone separator at the back. After combustion, the flue gas is separated in gas-solid phase in the cyclone separator. The high-temperature flue gas that is not separated enters the outlet flue through the upper outlet of the separator to the rear flue of the boiler, and the separated solid particles return to the lower part of the furnace through the refeeder.
In the operation of circulating fluidized bed boiler, the solid bed material containing fuel ash, limestone and their reaction products is in constant high-speed circulation flow in the closed loop of furnace, cyclone separator-rechargeer-furnace, and carries out high efficiency combustion and desulfurization reaction in the furnace. In addition to the external circulation flow of bed material in this circuit, the bed material is continuously circulated along the four walls of the furnace under the action of gravity.
Therefore, reliable anti-wear measures are taken in the corresponding parts of the circulation loop to prevent serious wear in the circulation loop, and it is important to ensure the construction quality of wear-resistant refractory materials and ensure the long-term and safe operation of the boiler.