What is a steam turbine

Heat engines

Large, multi-stage steam turbines are used in modern steam turbine power plants for generating electricity. The hot steam in the steam generator can be obtained by burning fossil fuels (e.g. coal, petroleum) or e.g. by a nuclear reactor. First of all, the very hot steam enters the high-pressure turbine and drives it. When leaving the high-pressure turbine, the pressure and temperature of the steam have decreased (the steam is said to "relax"). It is then fed into a medium-pressure turbine, for example, where it continues to relax, and finally a low-pressure turbine is driven with the steam. All turbines sit on the same axis, as does a large generator for generating electricity. In the condenser, the steam is cooled and turned into water. The condensed water is pumped back into the evaporator with the feed water pump. The cooling in the condenser takes place through a pipe system through which cold water from a river or cooled water from a cooling tower with the cooling water pump is passed. There are two circuits in the steam turbine power plant: the steam circuit and the cooling water circuit.

Modern steam turbine systems can generate outputs of around \ (1000 \, \ rm {MW} \). Here are some data from the steam turbine groups in the Lippendorf lignite power plant:

Power delivered to the generator
Live steam volume
Live steam pressure
Live steam temperature

For the energy supply in the age of the "energy turnaround", power plants are required that can quickly go into operation when there is currently a lack of wind and solar energy. So-called combined cycle power plants (gas and steam turbine power plants) have recently been developed here. With these types of power plants, electrical efficiencies in the region of 60% can be achieved.

Note: For those with a handicraft skill, there is a suggestion on the "Energy Makes School" page to build a steam turbine model yourself.