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Impact Estimation of a Transient Temperature Field on the Service Life of the High Pressure Rotor of K-1000-60/3000 Turbine

Chernousenko Olga, Nikulenkova Tetyana, Nikulenkov Anatolii

Rocznik Ochrona Środowiska

2021

Tom 23

408--419

The one of purposes of this paper is to estimation some impact on the service life of the high-pressure cylinder rotor of a typical high-speed turbine K-1000-60/3000. The residual life assessment of power equipment would require determining viability and damage of its base metal. Typical degradation mechanisms of steam turbine equipment include long-term strength reduction and low cycle fatigue accumulation. Intensity of their impact is determined by a numerical examination of equipment thermal (TS) and stress strain states (SSS) for standard operation modes. To perform a numerical examination of the stress strain state would require solving a thermal conductivity boundary problem in quasi-stationary (for nomal operation modes) and nonstationary models (for transients). It is convenient to solve such problems of mathematical physics through discretization of the calculation object using the finite element method (Chernousenko et al. 2018). The service life of steam turbine is determined as an individual one and is assigned based on the results of individual an inspection of a separate element or the largest group of single-type equipment elements of the considered plant. The fleet service life being reached is followed by diagnostics of specific units of power installations and analysis of their operation, measurement of actual dimensions of components, examination of structure, properties and damage accumulation in the metal, non-destructive testing and estimate of stress strain state and residual service life of the component. The results of performed studies are used to determine an individual service life of each element of energy equipment (Nikulenkov et al. 2018).

Obliczeniowa dynamika płynów w analizie zagadnień smarowania hydrodynamicznego

Dąbrowski L., Rotta G., Wasilczuk M.

Tribologia

2008

nr 2

137-143

Współczesne systemy obliczeniowe obliczeniowej dynamiki płynów (ang. Computational Fluid Dynamics - CFD) i szybkie komputery zwiększają możliwości rozwiązywania dotychczas nierozwiązanych problemów hydrodynamicznej teorii smarowania. Z drugiej jednak strony wykorzystywanie systemów CFD do rozwiązywania złożonych zagadnień smarowania hydrodynamicznego nie jest zadaniem prostym. Systemy obliczeniowe były rozwijane do rozwiązywania zróżnicowanych zadań i w przypadku smarowania hydrodynamicznego konieczne jest specjalne podejście, aby uniknąć problemów numerycznych i otrzymywać wiarygodne wyniki. W początkowych etapach badań przeprowadzono badania wpływu gęstości podziału modelu CFD na wyniki, porównywano uzyskiwane wyniki ze znanymi rozwiązaniami analitycznymi itp. ([L. 1, 2]). Kolejnym analizowanym zagadnieniem jest wpływ konstrukcji przestrzeni między segmentami łożyska wzdłużnego i zachodzących w nich zjawisk na temperaturę środka smarowego w strefie wlotowej i, co za tym idzie, właściwości łożyska.

Despite the fact that hydrodynamic theory is over one hundred years old, and numerical simulations have been applied in early 1960's, there are still a lot of problems which are not solved. Very often their origin lies in the nature of other phenomena accompanying lubricant flow in the film, such as fluid flow in the groove between and around bearing pads or heat transfer in whole bearing system. Nowadays, modern Computational Fluid Dynamics (CFD) codes, both commercial and freeware and very fast computers enhance the possibilities of solving some problems that have been impossible to solve up till now. On the other hand application of CFD codes for solving advanced lubrication problems is not a straightforward task. General-purpose CFD codes have been devised for solving a large variety of problems and in case of specific features of film lubrication special approach is necessary to obtain relevant results and avoid numerical problems. The authors attempt to utilise CFD codes for the calculations of hydrodynamic thrust bearings. In this paper some aspects of CFD applications are discussed. The discussed aspects comprise convergence criteria, mesh size and type of flow.