What is a boiler and what is its principle?

Boilers are mechanical devices that use heat energy from fuel or other sources of energy to heat water into hot water or steam. The original meaning of pot refers to the water container heated on the fire. The furnace refers to the place where fuel is burned. The boiler consists of pot and furnace.
Hot water or steam generated in boilers can directly provide the thermal energy needed for industrial production and people's lives. It can also be converted into mechanical energy through steam power devices or into electrical energy through generators.
Boilers that provide hot water are called hot water boilers. They are mainly used in daily life and also in industrial production. Boilers that produce steam are called steam boilers, often referred to as boilers, and are mostly used in thermal power plants, ships, locomotives and industrial and mining enterprises.
Boiler is a kind of energy conversion equipment. The energy input to the boiler is in the form of chemical energy, electric energy, heat energy of high temperature flue gas, etc. After boiler conversion, steam, high temperature water or organic heat carrier with certain heat energy is exported.