1. Boiler

　　Boiler refers to the use of fuel combustion heat or other thermal energy released to heat water or other masses, in order to produce the specified parameters (temperature, pressure) and quality of steam, hot water or other masses of equipment.

　　2. Boiler working principle and working characteristics

　　(1) working principle.

　　(2) working characteristics

　　1) explosion hazard.

　　2) easy to damage.

　　3) The use of a wide range.

　　4) continuous operation.

　　3. Classification of boilers

　　(1) according to the use of power station boilers, industrial boilers.

　　(2) According to the steam pressure generated by the boiler is divided into supercritical pressure boilers, subcritical pressure boilers, ultra-high-pressure boilers, high-pressure boilers, medium-pressure boilers, low-pressure boilers.

　　(3) According to the evaporation capacity of the boiler is divided into large, medium and small boilers.

　　(4) According to the heat-carrying medium is divided into steam boilers, hot water boilers and organic heat carrier boilers.

　　(5) According to the source of heat energy is divided into coal-fired boilers, oil-fired boilers, gas-fired boilers, waste heat boilers, electric boilers.

　　(6) According to the boiler structure is divided into pot shell boilers, water tube boilers.