METHOD OF INTEGRATED ASSESSMENT OF FATIGUE STRESSES IN THE STRUCTURE OF THE RESTORED BLADES OF CHP AND HPS

• Main Authors: Vitalii V. Savinkin, Viktoria N. Kuznetsova, Tatyana Yu. Ratushnaya, Leonid A. Kiselev
• Format: Article
• Language: Russian
• Published: Tomsk Polytechnic University 2019-08-01
• Series: Известия Томского политехнического университета: Инжиниринг георесурсов
• Subjects: fatigue stresses; phase structure; turbine bladeъ; integrated assessment; non-destructive testing methods
• Online Access: http://izvestiya.tpu.ru/archive/article/view/2213/2036
• ISSN: 2500-1019; 2413-1830

The relevance of research is caused by the necessity to develop the method of precise definition of the resource durability and reliability of heavily loaded equipment used for energy production and conversion on the basis of geo-resources (hydro, CHP), based on identification of zones of concentration of internal stresses, as an indicator of phase change in the material structure of the parts. The main aim of the research is to increase resource durability of loaded turbine blades of hydro and thermal power stations due to implementation of the developed integrated methodology of precise prediction of structural-phase changes at the early stages of fatigue defects. The object of research is the turbine blades of CHP and HPP, restored by a source of laser-plasma energy. The complex research method was used to study the concentration of internal stresses in the structure of loaded parts subjected to dynamic loads. The methodology of system analysis was used, as well as the method of distribution of the residual magnetization field in the degraded microstructure of the material. In development of the algorithm of the integrated method of diagnosis and accurate prediction, the methods of mathematical statistics were used. The restored parts were studied by nondestructive testing followed by analysis and processing of the results. Result. The authors have developed the algorithm of diagnostics of the restored details of high-tech complexes of energy production and transformation of georesources, on the example of turbine blades of hydroelectric power station. A database of blade stress concentrations depending on the phase structure of the metal was formed, which allows establishing the cause-and-effect relationships between the defect, technological recovery modes and operating modes of the unit. The scientific problem of creating a single physical model is solved and the limits of applicability of this method are determined. The authors determined the safe operation mode of power equipment (Нх=62–76 A/m), which increases the turbine life by 1,7 times.