Let's classify the various types of steam turbines~

Classified by Inlet Parameters

Low-pressure steam turbine:

The main steam pressure is 1.2~2.0MPa. (For example, the main steam pressure of a unit is 1.35MPa and the temperature is 350°C) 

Medium pressure steam turbine:

The main steam pressure is 2.1~4.0MPa. (For example, the main steam pressure of a unit is 3.45MPa and the temperature is 430°C) 

High-pressure steam turbine:

The main steam pressure is 6.0~12.0MPa. (For example, the main steam pressure of a unit is 9.5MPa and the temperature is 520°C)

Ultra-high pressure steam turbine:

the main steam pressure is 12.6~15.0MPa. (For example, the main steam pressure of a unit is 13MPa, the temperature is 535°C, and the reheat temperature is 535°C) 

Subcritical pressure steam turbine:

the main steam pressure is 15.1~22.5MPa. (For example, the main steam pressure of a unit is 16.5MPa, the temperature is 535°C, and the reheat temperature is 535°C) 

Supercritical pressure steam turbine:

The main steam pressure is greater than 22.1MPa. (For example, the parameters of a 660MW supercritical steam turbine are: main steam pressure 23.8MPa, temperature 560°C, reheat steam temperature 560°C)

Ultra-supercritical pressure steam turbine:

The main steam pressure is greater than 27MPa or the steam temperature reaches 600°C. (For example, the parameters of a 1000MW ultra-supercritical steam turbine are: main steam pressure 26.5MPa, temperature 600°C, reheat steam temperature 600°C)

Classified by Thermal Process Characteristics

Condensing steam turbine:

After the steam expands in the steam turbine to do work, it enters the condenser in a high vacuum state and condenses into water. Some steam turbines do not have a steam extraction and recuperation system, which is called a pure condensing steam turbine; In order to improve the circulating thermal efficiency, modern steam turbines generally use several sections of recuperation extraction pipes to heat the feed water, and this kind of steam turbine is still customarily called condensing steam turbine. 

Back-pressure steam turbine:

After the steam enters the steam turbine at all levels for work, the exhaust steam is higher than the atmospheric pressure, and it is directly used for industrial or domestic heating, without a condenser. This type of steam turbine is called a back-pressure steam turbine.

Regulating the extraction steam turbine:

A certain parameter and a certain amount of steam are extracted from a certain stage or several stages in the middle of the steam turbine for external heating, and the rest of the exhaust steam still enters the condenser. This type of steam turbine is called a regulated extraction steam turbine. Since the heat user has certain requirements for the heating steam pressure, it is necessary to adjust the exhaust steam heating pressure to meet the user's needs. Generally, it is divided into primary steam extraction adjustment and secondary steam extraction adjustment.

Intermediate reheat steam turbine:

After the steam entering the steam turbine is expanded to do work through several stages, it is reintroduced into the reheater of the boiler for heating, and then returns to the steam turbine to continue to expand and do work, and the steam enters the condenser, which is called an intermediate reheat steam turbine.

Classified According to The Principle of Work

Impulse steam turbine:

It is mainly composed of an impulse stage that does work according to the principle of impulse, and the steam mainly expands in the nozzle blade grid, and only a small amount expands in the moving blade grid. In order to improve the efficiency of the unit, the impulse steam turbine has a certain degree of reaction, and it is still customary to call the impulse steam turbine. 

Reactionary steam turbine:

It is mainly composed of a reactionary stage that does work according to the principle of anti-impulse, and the steam expands to the same degree in the nozzle vane grid and the moving vane grid. Because the reactionary stage cannot be made into a structure of partial steam intake, the regulating stage often adopts a single-row impulse stage or a complex speed stage, but it is still used to be called a reactionary steam turbine.

Categorized by The Purpose of Use

Power station steam turbine:

Used to drag the generator, the steam turbine generator set needs to run at a fixed speed according to the power supply frequency, also known as a fixed speed steam turbine.

Industrial steam turbines:

Used to drag fans, pumps and other rotating machinery, and their operating speed is often variable, also known as variable speed steam turbines. 

Marine steam turbines:

Used in marine propulsion power units, the speed and steering of which are constantly changing.

Categorized by Other Ways 

In addition to the above classifications, it can also be divided into single-cylinder steam turbine and multi-cylinder steam turbine according to the number of cylinders of the steam turbine; According to the number of shafts, it can be divided into single-shaft steam turbine and double-shaft steam turbine.