The boiler superheater is a component in the boiler that further heats the steam from the saturation temperature to the superheated temperature, also known as the steam superheater. The superheater can be divided into convection type, radiation type and semi-radiant type according to the heat transfer mode; according to the structural characteristics, it can be divided into serpentine type, screen type, wall type and wall-enclosed type. They all consist of several parallel pipes and inlet and outlet headers.
In power plants, locomotives and marine boilers, in order to improve the cycle thermal efficiency of the entire steam power plant, superheaters are generally installed.
A superheater is a device that heats saturated steam into superheated steam with a certain temperature. After the saturated steam is heated into superheated steam, the working ability of the steam in the steam turbine is improved, that is, the useful enthalpy of the steam in the steam turbine is increased, thereby improving the cycle efficiency of the heat engine.
In addition, the use of hot steam can also reduce the humidity of the exhaust steam of the steam turbine, avoid the corrosion of the steam turbine blades, and create favorable conditions for the steam turbine to further reduce the exhaust steam pressure and operate safely.
The metal of the superheater tube wall bears the highest temperature in the pressure parts of the boiler, so high-quality low-carbon steel and various chromium-molybdenum alloy steels with high temperature resistance must be used. In the highest temperature part, austenitic chromium-nickel stainless steel is sometimes used. . If the temperature of the pipeline during boiler operation exceeds the allowable temperature limit of the permanent strength, fatigue strength or surface oxidation of the material, accidents such as pipeline bursting will occur.