Steam turbine flow path drainage system under different operating conditions

Abstract

One of the important elements of anti-erosion protection of the steam turbine last blades is the use of hollow stator blades. There are grooves on the blade surface that lead the steam mixture inside the blades. This mixture is blown to the diffuser area. However, the drain principle fails for low outputs of the turbine, during the so-called ventilation regimes. In the part of blade section the steam flow is reversed and the flow part drain stops working. It was confirmed using experiments of steam turbine carried out in a wide range of power outputs.