On the rational form of rotary control diaphragms for steam turbines with industrial and cogeneration steam extraction

National Research University “Moscow Power Engineering Institute, Institute of power engineering and mechanic, Department of steam and gas turbines, Krasnokazarmennaya 14, 111250 Moscow, Russian Federation

^* Corresponding author: lavirev@mail.ru

Abstract

The Russian park of power steam turbines contains a large number of turbines with adjustable steam extraction from the flow path where rotary control diaphragms are used as flow controllers, which structurally easily fit into the flow path of these turbines. This method of regulating the steam flow rate is accompanied by a decrease in the efficiency of the subsequent stages of the turbine and causes the appearance, at reduced loads, of additional disturbing forces acting on the rotor blades. In the presented materials, a variant of a post-sampling stage with a radial rotary control diaphragm is considered. The performed mathematical modeling of the working fluid flows in such a stage showed that in this case, at all turbine loads, a relatively uniform velocity field is provided when steam enters the nozzle apparatus, which naturally entails the elimination of the noted drawbacks.