Turbines are mechanical devices that utilize high-pressure steam to rotate the blades, thereby generating power. Their primary working principle is to convert a portion of the steam's thermal energy into high-speed airflow through expansion, which then drives the blades to rotate and transform this motion into kinetic energy. Inside the turbine, the steam passes through a nozzle chamber where it is depressurized, accelerated, and redirected, converting thermal energy into kinetic energy and being directed towards the moving blades. The moving blades, propelled by the combined force of the steam's impact and reaction, drive the turbine's main shaft to rotate, thus producing mechanical work.

Turbines are generally categorized into two types: impulse and reaction. In an impulse turbine, steam undergoes降压, expansion, and acceleration only in the stationary blade row, without any pressure drop or expansion in the moving blade row, where the moving blades merely convert steam's kinetic energy into mechanical work. In a reaction turbine, steam performs pressure drop, expansion, and acceleration both in the stationary and moving blade rows. The moving blades not only convert the steam's kinetic energy into mechanical work but also transform part of the steam's internal energy into mechanical work.

The main components of a steam turbine include the rotor (impeller, blades), stationary parts (shutters, nozzles, cylinders), and other components (steam seals, shaft bearings). To achieve the required power, steam turbines are typically composed of several stages in series.