Topical Problems Associated with Reliability and Safety of Equipment at Thermal Power Stations

The basic problems important for the industrial safety of equipment at thermal power stations (TPS) are formulated. The issues of determination of the residual service life of equipment experiencing high-temperature creep are examined. The correlation between the actual metal properties and the safety factor, as well as the effect of stressed state on accumulation of microdamages in the metal, are considered. The in-service margins of the high-temperature equipment are analyzed from the standpoint of the equipment fitness for service. The damage mechanism of the equipment operating at temperatures below the creep temperature is analyzed, and the in-service margin of this equipment is evaluated. Low efficiency of the examination of the metal conditions using specimens cut out from the equipment operating at moderate temperatures is stated, while strict requirements are imposed on the scope and quality of diagnostics. The current state of affairs in the field of standardization of the diagnostics and fitness for service assessment of thermal mechanical equipment is considered. It is noted that the procedure for setting up the schedule of technical diagnostics and industrial safety expertise of power equipment and the regulations for performance of these procedures have been revised. The principal provisions and requirements included in the newly introduced regulatory documents having the status of Federal Norms and Rules are examined. It is proposed to extend the terms of reference and enhance the capabilities and responsibility of expert organizations. The issues associated with ensuring the reliability of revamping and greenfield projects are analyzed. The advantages of chromium steels with increased heat-resistance in the manufacture of high-temperature equipment are demonstrated. However, the use of chromium steel in equipment with an operating temperature below 560°С is impractical from both the economic and engineering standpoint. The experience with performance of certification tests is briefly described, and the fact that this procedure enjoys current interest is demonstrated. The need is outlined for a thorough revision of the existing regulations on routine inspection and diagnostics of thermal engineering equipment because of its use in assemblies or elements made from new steels.