Coal-fired boiler converts chemical energy into heat energy through combustion, so that the water in the boiler can be heated to a certain temperature to become hot water or steam. At present, coal boiler of thermal power plant has large capacity, high parameter, complex technology, high level of mechanization and automation, so the fuel is mainly coal, and coal is made into pulverized coal before combustion, and then sent to the boiler to burn and release heat in the furnace. In short, the boiler is the main working process in terms of fuel combustion, heat transfer, water heating with vaporization and steam overheating, etc.
The feed coal of chain grate boiler falls on the chain grate from the coal sill in front of the furnace by the dead weight of coal, and the grate moves slowly from front to back. The different stages of coal seam combustion are completed at one time as the coal moves on the grate. The incinerated slag falls on the cinder bucket by a slag eliminator at the end of the grate. The coal-fired boilers produced by ZOZEN have a high degree of automation, and have won the recognition and trust of many users especially in the overseas market, because the main operations such as adding coal, removing slag and removing ash are completed by machinery and the operation is reliable and stable. It is ZOZEN technical team’s continuous study on the working principle of coal-fired boilers that makes the performance of coal-fired boilers improve.
The circulating fluidized bed (CFB) coal boiler organizes the coal combustion process based on the principle of circulating fluidization and is characterized by the circulating combustion of a large number of high temperature solid particles carrying fuel. A mode of combustion in which solid particles fill the entire chamber, are suspended and strongly blended. But with the conventional pulverized coal furnace than pure suspension combustion process, the concentration of the particles in the circulating fluidized bed combustion chamber than pulverized coal furnace, and significant particle clouds and bed material particles backmixing, relative velocity between the particle and gas is large, it clearly and suspension based on pneumatic conveying of pulverized coal combustion process is completely different.
In the CFB boiler, desulfurizer is desulphurized in the furnace under the optimal reaction temperature. The internal circulation of fuel and materials in the furnace and the external circulation caused by the separation equipment and the return equipment make the desulfurizer’s average residence time in the furnace as long as dozens of minutes. Therefore, the desulfurization process can be fully carried out. Under the condition of using limestone as desulfurizer Ca/S=2, the desulfurization efficiency can reach above 90%, the utilization rate of the solvent can reach above 50%, and the SO2 content in the flue gas discharged into the atmosphere (standard state) is less than 200mg/m3, which conforms to the national environmental protection standards, so it is unnecessary to use the expensive flue gas desulfurization device.
ZOZEN’s products have successful cases in all industries. A series of characteristics of circulating fluidized bed boiler have gradually developed into a coal fired boiler with wide range of fuel, high efficiency and low pollution, which is not only suitable for industrial boilers, but also for large power station boilers, with broad application and development prospects.