Erosion Wear Caused by Coarse Particles in the Flow-Through Part of the Medium-Pressure Stage of T-250/300-240 Turbines

The problem of erosion wear of the first stages of IPC-1 of T-250/300-240 turbines by solid particles is briefly described. It is shown that solid particles arriving at the flow-through part of intermediate-pressure cylinders form as a result of decomposition of an oxide film in the convective superheater piping of supercritical boilers. Fracture of the oxide film is intensified due to the temperature mode of the boiler and changes in the water chemistry. A general picture of wear of the flow-through part including guide and moving blades, shroud seals, and elements of the peripheral zone of the first intermediate-pressure stages by solid particles is presented. Wear of the flow-through part reduces the service life of the blading to two interrepair periods and substantially worsens the efficiency of operation of the intermediate-pressure part. The mechanism of motion of solid particles in the flow-through part is described and the ways to decrease the wear by removing solid particles from the hot reheat line, shutoff valves, and the first intermediate-pressure stage are considered. The latter method has been realized in the form of a protection system containing continuous or periodic double-loop blow. The first loop extracts a steam sample with solid particles from the steam-in box and the second loop removes solid particles from the increased blade clearance of the first stage into a separator-accumulator from which the cleaned steam is returned to the nearest extraction of the turbine. The operating experience of such a system confirms its expedience.     

Activities of Pt/Sibunit-1562 catalysts in the ORR in PEMFC: Effect of Pt content and Pt load at cathode

In this paper, a systematic investigation was carried out of activities at 80 °C of Pt supported on Sibunit-1562 graphitized carbon in the electroreduction of oxygen in the polymer electrolyte fuel cell. Pt content in the Pt/Sibunit-1562 catalysts was 20, 40, and 60 wt.% and Pt load at the cathode was varied in the 200–6.25 μg_Pt cm⁻² interval. The results were compared with the activity of commercial 20 wt.% Pt/Vulcan XC-72 catalyst. To optimize the transport properties of the cathode layer and maintain its thickness upon using Pt/Sibunit −1562 catalysts with varied Pt content and Pt loads a definite amount of Vulcan-XC-72 carbon support was added to the cathode catalytic inks. Higher activity of Pt/Sibunit-1562 catalysts was found as compared to that of commercial 20 wt.% Pt/Vulcan XC-72 with similar particle size of the active component.     

Analyzing the causes and sources of increased content of oxygen in the condensate of T-250/300-240 cogeneration turbines

The problem of reducing the content of oxygen in the turbine condensate of supercritical-pressure cogeneration-turbine condensers is discussed. The sources, causes, and conditions responsible for this problem are analyzed, and measures for preventing and eliminating the causes and consequences of an increased content of oxygen are proposed, which have been implemented in the T-250/300-240 turbines at the TETs-23 cogeneration station and tested during operation.     

Certain kinematic characteristics of the boundary layer at a streamlined elastic plate

Results of measurements are presented pertaining to the coefficients of lateral, in space, correlations and the spectral density of longitudinal velocity fluctuations at a rigid plate and at an elastic plate.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 38, No. 6, pp. 1049–1055, June, 1980.