Analysis of the effect of mechanical impurities in water on the hydroabrasive wear of the turbines of the Bozsu hydroelectric power plant

Abstract

The peculiarity of the operation of hydropower facilities (pumping stations and hydroelectric power plants) in the Republic of Uzbekistan is that the equipment works with liquids containing a large amount of mechanical impurities. The purpose of the research is to assess the effect of the content of mechanical impurities in water on waterjet wear. The object of research is the Bozsu HPP (Uzbekistan). To assess the hydroabrasive properties of a liquid with impurities, an analysis of the granulometric and mineralogical composition of sediments and especially those fractions of impurities that pose a danger was carried out. For water passing through the turbins of the Bozsu HPP, these are fractions of feldspar and quartz. Most of the composition of mechanical impurities are feldspar minerals (58.46% with an average diameter of 0.093 mm). The total content of hazardous fractions (feldspar and quartz) is 77.07% or 0.3-0.4 kg/m3, which exceeds the maximum permissible norm (0.2 kg/m3). But at the same time, no dangerous fractions in diameter (more than 0.25 mm) were detected. A full-scale inspection of the turbine parts showed that waterjet wear is present. The type of waterjet wear is fine-scaled wear with rare, separately located, shallow scales and deep (deep) type of wear with long grooves. The degree of waterjet wear quantitatively and qualitatively, this can be attributed to the wear of low and medium activity.