The main working principle of the boiler is a thermal equipment that transfers the heat energy released after fuel combustion or the waste heat in industrial production to the water in the container to make the water reach the required temperature or a certain pressure of steam. The boiler is carried out at the same time in both "boiler" and "boiler" parts. After the water enters the boiler, the heat absorbed by the boiler heating surface in the steam water system will be transferred to the water supply, so that the water can be heated into hot water of certain temperature and pressure or generate steam, which will be led out for application. In the combustion equipment part, the fuel combustion continuously emits heat. The high temperature flue gas generated by combustion transfers heat to the heating surface of the boiler through heat transmission, while its temperature gradually decreases, and finally it is discharged from the chimney

The original meaning of the boiler refers to the water container heated on the fire, and the furnace refers to the place where fuel is burned. The boiler includes the boiler and the furnace. The hot water or steam generated in the boiler can directly provide the required heat energy for industrial production and people's life, and can also be converted into mechanical energy through the steam power device, or converted into electrical energy through the generator. The boiler that provides hot water is called hot water boiler, which is mainly used for life, and also has a small number of applications in industrial production. The boiler that generates steam is called steam boiler, often referred to as boiler for short, and is mainly used in thermal power plants, ships, locomotives and industrial and mining enterprises.