Erosion of steam turbines: a probabilistic approach: in 3 vol. Vol. 3. Prevention of steam turbine erosion

Based on the analysis of the main probability patterns of erosion wear of materials and full-scale structures, the probabilistic theory of erosion of steam turbines is developed, the calculated methods for predicting the erosion state of the parts of the flow part of wet-steam turbines during operation are developed, and effective passive methods for improving the parametric erosion reliability of steam turbine equipment are proposed. In volume 3 reflects the questions of creation of effective techniques for the prevention of erosion damage to main structural elements of the flow part of the turbine: strategy planning repair wet turbines with the replacement of extremely worn-out rotor blades, and the grading of the eroding elements, causing erosion of protective coatings (overlays), modify the properties of the material and surface hardening, technical diagnostics and monitoring the erosion state of the work of the blading of steam turbines. Chapter 6. Bases of formation of strategy of repair of the eroding turbine stages with replacement of extremely worn-out working blades. Probabilistic evaluation of economic efficiency and kinetics of the performance efficiency of turbine stages with well-known strategy of replacements blades. Planning the strategy of substitutions eroded blades. Optimization strategy of substitutions eroded blades. Chapter 7. Passive methods of anti-erosion protection of structural elements of the steam turbine flow. Method of passive protection of elements of a turbine disk from water-jet erosion. Selective method for a set of protective Stellite plates of working blades. Surface protection of structural elements coatings and various types of hardening. Design and experience of application of various types of erosion-resistant surface protection of structural elements of wet-steam turbines. Experimental studies of erosion resistance of materials for protective coatings of structural elements of wet steam stages. Wave models of formation of the stress state of structural elements with coatings and hardening. Probabilistic models of mechanisms of exhaustion of the resource of surface anti-erosion protection. Selection of design parameters of erosion-resistant coatings. Selection of a rational degree of hardening and the law of hardness change in the thickness of the surface protection. Working blade with edges of increased erosion and fatigue resistance. The method of approximate estimation of changes in the vibration characteristics of the blade apparatus in the separation of Stellite plates. Chapter 8. The subsystem of technical diagnostics of the erosion of the status of the blade devices of steam turbines. Functionality and technical requirements for the diagnostic subsystem. The composition of the functional support of the diagnostic subsystem. The scheme of functioning of the diagnostic subsystem