Исследование течения жидкости в зоне «спираль – статор» гидротурбины РО 310 с плоскими кольцами статора

Abstract

Considered one of the critical units of the Francis turbine – node "spiral chamber – stator". The turbine stator is the supply element of the flow path of the turbine, which is involved in the formation of flow in front of the impeller. In this paper, the design of the stator with flat rings, the columns of which are pushed into the spiral chamber, is considered. This design of the stator allows you to save the main dimensions of the spiral in the plan for hydraulic turbines with built-in ring gate. Information analysis showed that, along with constructive and technological advantages, the use of stator rings of the column, which are pushed into the spiral chamber, have hydrodynamic disadvantages. Under the considered design of the "spiral – stator with flat rings" assembly, the plot of the meridional velocity component is deformed. As a result, the energy losses associated with flow separation and secondary flows in the spiral chamber can increase. Hydrodynamic studies of the flow structure in the "spiral – stator" zone with flat stator rings are presented – experimental and numerical calculations. It is proposed to study the shape of the stator rings to calculate the axisymmetric flow in the limited "spiral – stator" calculation zone of the turbine using a two-layer model of viscous fluid motion. The experimental data of pressure measurement on the surface of the stator rings are given. Comparison of calculated and experimental data gives a qualitative match. For three variants of stator rings, the boundary layer was calculated in the work. The results showed that the maximum blockage of the stator channel boundary layer reaches 5,2 %. The calculation of the turbulent boundary layer showed that for the studied variants of the rings of local boundary layer separation is not observed. The calculation of the flow around a lattice of stator column profiles on an axisymmetric current surface with the subsequent determination of the profile and impact losses was carried out. The proposed improvement of the method of calculation.