Influence of the temperature of the heating steam on the characteristics of the liquid phase downstream the stator blades of steam turbine

Abstract

The paper presents the results of an experimental study of the efficiency of heating with the injection of steam on the surface of the stator blades of the last stages of steam turbines operating in the wet steam flow conditions. The major task of the research was to determine the main mechanisms of the heating temperature influence on the kinematic characteristics of the polydisperse flow of a liquid phase downstream an isolated nozzle blade cascade. Measurement of the characteristics of the liquid phase particles was carried out using a laser flow diagnostic system implemented on the basis of the “PIV-IT”complex and processing the obtained images using the PTV method (particle tracking velocimetry). It is established that heating leads to evaporation of the liquid film formed as a result of the deposition of liquid phase on the surfaces of the nozzle blades, as well as to the increase in the velocities of droplets, and as a consequence, a decrease in diameters and wetness.