A condensing turbine is a low pressure - steam turbine in which the steam to the saturated steam condition, or even into the wet steam is -region in relaxed, so that condensation in the exhaust steam enters.
The condensation turbine thus represents the counterpart to the back pressure turbine , in which exhaust steam is extracted in the overpressure range and is superheated , for example in order to use it as process steam ( combined heat and power ).
The condensation turbine is the usual design of steam turbines in steam power plants for generating electricity. A condenser is connected downstream of the turbine, which generates the lowest possible temperature and thus the lowest possible back pressure ( negative pressure ). In this way, maximum energy yield and maximum efficiency are achieved.
Since the steam has a very high specific volume at the low pressures in the vacuum range, condensation turbines have very large exhaust steam volume flows and thus very large exhaust steam cross-sections and very long end blades . The high peripheral speed of the blades in connection with the condensate droplets in the steam can lead to droplet erosion . The surface of the end vanes is therefore usually hardened or coated .