Extraction condensing turbine
An extraction condensation turbine (also known as extraction steam turbine ) is a steam turbine in which part of the steam can be extracted at higher pressures, but it is also possible to fully utilize the steam enthalpy up to the condensation pressure .
The steam turbine has one or more taps from which partially expanded steam can be taken for district heating or for an industrial process (compare: combined heat and power ). This steam, which is extracted at the taps, has a higher temperature and pressure level than the fully expanded steam that is fed into the condenser after the turbine.
Control at the tapping points can be carried out by the following devices:
- through a withdrawal control wheel,
- adjustable guide vanes or
- an overflow throttle.
Such systems can be operated as required, so that when there is no heat requirement, all of the steam in the low-pressure part of the turbine is expanded. In this way, the enthalpy can be converted into technical work with the highest possible degree of efficiency up to partial condensation in the turbine and into electrical energy via the generator. Conversely, when useful heat is extracted, the electrical output is reduced ( power loss ), because the extracted steam can then no longer do any work in the low-pressure part of the turbine.
1 ... entry of the steam, E ... extraction point, 2 ... exhaust steam equal to the condensation state,
G ... generator, Ko ... condenser, HK .. .Heating condenser, MD ... medium pressure steam turbine part, LP ... low pressure steam turbine part, KoP ... condensate pump