Steam turbine is a kind of rotating machinery that uses steam as power and converts the thermal energy of steam into mechanical work. It is the most widely used prime mover in modern thermal power plants. It has the advantages of large single unit power, high efficiency, and long life. The principle is divided into impulse steam turbine and reaction steam turbine.

——The steam of impulse turbine mainly expands in the stationary blades, and there is only a small amount of expansion in the moving blades.

——The steam of the reaction steam turbine expands in the stationary blade and the moving blade, and the expansion degree is the same.