The overall structure of coal-fired boiler includes boiler body and auxiliary equipment. The furnace, drum, burner, water wall, superheater, economizer, air preheater, frame and furnace wall in boiler constitute the core part of steam generation, which is called boiler body. The two most important parts in the boiler body are the furnace and the drum. The structure of coal-fired boiler is as follows:

1. Furnace

The hearth is the combustion chamber, which is the space for fuel combustion. The cross section of the furnace is usually square or rectangular. Fuel burns in the furnace to form flame and high temperature flue gas, so the furnace wall around the furnace is composed of high temperature resistant materials and heat insulation materials. Water-cooled wall tubes are often laid on the inner surface of the furnace wall, which not only protects the furnace wall from being burned out, but also absorbs a lot of radiant heat from flames and high-temperature flue gas. The structure, shape, volume and height of the furnace should ensure the full combustion of fuel, and reduce the temperature of flue gas at the outlet of the furnace to below the temperature at which slag begins to condense.

Step 2 drum

The drum body is made of high-quality thick steel plate and is one of the heaviest parts in the boiler. The internal devices of steam drum include steam-water separation and steam cleaning device, water supply distribution pipe, sewage discharge and dosing equipment, etc. Among them, the function of the steam-water separation device is to separate saturated steam and water from the water wall, so as to minimize the fine water droplets carried in the steam.

3. Auxiliary equipment

In addition to the boiler itself, the utility boiler also has many auxiliary equipment: pulverized coal preparation system, which grinds raw coal into powder to facilitate the full combustion of coal, including coal feeder, coal pulverizer, powder exhauster, coarse powder separator and pulverized coal pipeline.

The structure of coal-fired boiler is complex, and the above are the main structural components of coal-fired boiler. In order to respond to the national requirements for boiler safety, energy conservation and environmental protection, the future development direction of coal-fired boilers is to focus on energy conservation and emission reduction, and strive to achieve a balance between economic development and environmental protection.