Investigation of the influence of intra-channel liquid film suction on the structure of the droplet flow downstream a stator blades cascade of a steam turbine

Abstract

The work is devoted to the study of the effect of intra-channel liquid film suction on the characteristics of the wet steam flow downstream a stator blades cascade of a steam turbine. The moisture removal system consisted of two slots on the pressure side of the blade. Each slot was connected to an individual suction chamber. The investigations were carried out with a theoretical Mach number downstream the cascade M 1t = 0.78 and an initial steam wetness y 0 = 3%. The main feature of the research was the use of a "PIV-IT" flow laser diagnostics system in which the PTV method was realized. This allowed conducting a detailed study of the structure of a polydisperse wet steam flow. During the investigation an idea of the complex structure of droplets flows downstream the turbine cascade was generated. The analysis of the obtained data allowed us to reveal the main features of the influence of intra-channel liquid film suction on the flows of the liquid particles. It is established that moisture removal does not have a significant effect on the velocity characteristics of the liquid phase. At the same time, the results of studies have shown that intra-channel liquid film suction systems reduce the number of coarse erosion-hazardous droplets downstream a stator blades cascade.