Answer to Question #165024 in Molecular Physics | Thermodynamics for Rohit

Question

Consider the steady flow of steam through a steam turbine at 6Mpa

Answer 1

The principle of operation of a steam turbine is relatively simple, and its internal structure has not fundamentally changed for over a century. To understand how a turbine works, consider how a thermal power plant works - a place where fossil fuels (gas, coal, fuel oil) are converted into electricity.

The steam turbine itself does not work; it needs steam to function. Therefore, the power plant begins with a boiler, in which fuel is burned, giving off heat to pipes with distilled water that passes through the boiler. In these thin pipes, water is converted to steam.

The turbine is a shaft (rotor) with radially spaced blades, like a large fan. Behind each such disk is a stator - a similar disk with blades of a different shape, which is fixed not on the shaft, but on the housing of the turbine itself, and therefore remains stationary (hence the name - stator).

A pair of one rotating disc with blades and a stator is called a stage. There are dozens of stages in one steam turbine - having passed steam through just one stage, the heavy turbine shaft with a mass from 3 to 150 tons cannot be unwound, therefore the stages are sequentially grouped in order to extract the maximum potential energy of steam.

Steam is supplied to the turbine inlet at a very high temperature and under high pressure. Turbines of low (up to 1.2 MPa), medium (up to 5 MPa), high (up to 15 MPa), ultra-high (15-22.5 MPa), and supercritical (over 22.5 MPa) pressures are distinguished by steam pressure.