Translated from Gidrotechnicheskoe Stroitel 'stvo, No. 2, February 2014, pp. 52 -58. Different approaches to problems associated with evaluation of the strength and service life of hydraulic turbines with service lives exceeding the period assigned by the manufacturer are compared. Significant differences in approaches to strength evaluation in the design, construction, and modernization stages, and during an extension in service life are cited. A complex approach permitting establishment of a valid prediction of the behavior of a hydraulic turbine during an extended period of operation is proposed for assessment of remaining service life.The service life of a hydraulic turbine assigned by the manufacturer and secured in standard documents [1, 2] is calculated in years, irrespective of the average-annual running time, and depends on the fabrication date of the turbine: 30 years -for turbines fabricated prior to 1 January 1991; and, 40 years -for turbines fabricated after 1 January 1991. At the present time, the majority of hydraulic turbines operating within the Russian landmass have already exhausted their assigned service life, and for some, it has been exceeded by a factor of nearly two. Moreover, basic equipment components frequently have yet to attain their physical and limiting wear, and, consequently, replacement of the turbines is not a priority problem. Standard document [1] calls for the possibility of repeated staged extension of the service life of basic equipment right up to its having attained the limiting state for which its continued service is disallowed or inexpedient. The possibility of continued reliable and failsafe service of a hydraulic turbine after attaining its assigned service life should be substantiated. A procedure for extension of the service life, which is based on assessment of remaining service life of the hydraulic turbine, i.e., its total running time from the moment of monitoring its current technical condition to its transition to the limiting state, is carried out for this purpose. Moreover, additional restrictions on operating conditions, and intermediate surveys, inspections and testing should be established when needed.As in other fields of power engineering, problems involving extension of service life for water-power equipment should be regulated by standard documentation. A number of new documents establishing requirements for assessment of technical condition, and a procedure for extending the service life of equipment components at HPP have been developed in recent years [3 -11].Until now, however, it has been impossible to speak of extenuating and uniform approaches employed by various specialized organizations for solution of the problem of the possibility of extending the service lives of hydraulic turbines. The diversity and incomparability of the procedures used do not allow for comparison of remaining-life characteristics of hydraulic turbines operating at different HPP, and even monotypic turbines within the bounds of the same plant.A brief description of t...
