Adjustable (rotated) stator blade aerodynamics in adaptive control of extraction/condensing turbines

Cogeneration of electric energy and heat as well as seasonal changes of the condenser pressure in low-pressure extraction/condensing turbines require adaptive control to adapt the geometry of the blading system to the changing flow conditions. In this paper adaptive control is achieved by means of restaggering (rotating) adjustable stator blades. An increase of turbine efficiency and power coming from adaptive control is numerically estimated for a group of two exit stages of an extraction/condensing turbine of power 60 MW. The calculations are made with the help of a computer code FlowER – a 3D solver of turbomachinery flows based on Reynolds-averaged Navier-Stokes equations for perfect gas.