Estimating Workability of Steam Boilers Superheaters Considering with the High-Temperature Creep and Uniform Chemical Corrosion
DOI:
https://doi.org/10.20998/2078-774X.2019.03.11Анотація
It is proposed theoretical estimating workability of steam boilers superheaters on the base of considering the influence of a high-temperature uniform chemical corrosion on of a high-temperature creep of superheater pipes on account of stresses redistributions the pipes walls due to their thickness decreasing. The high-temperature uniform chemical corrosion is presented by the well-known time and temperature dependences of the height of damaged material. The high-temperature creep is considered using the well-known incremental-type theory taking into account the Cachanov-Rabotnov scalar damage parameter. It is proposed the mathematical model of state of superheaters pipes in the form of initial-boundary-value problem in the domain with the moving boundary. The differential equations, initial and boundary conditions of that problem are corresponded to the well-known in the theory of high-temperature creep. Moving of the boundary is corresponded to the well-known time dependence of the height of damaged material due to the high-temperature uniform chemical corrosion. Although, the used theory of creep and the used regularities of uniform corrosion are well-known separately, considering the influence of uniform corrosion on the creep is the complicated problem due to the moving boundary in the corresponded initial-boundary-value problem. It is shown, that the spatial variable replacement allows to reduce the proposed initial-boundary-value problem with the moving boundary to the initial-boundary-value problem with the fixed normed boundary, that allows to simplify numerical solving of the considered problem. The method of lines is discussed for solving the initial-boundary-value problem, representing the mathematical model of the state of pipes of superheaters.
Посилання
Annaratone D. Steam Generators Description and Design. Berlin Heidelberg: Springer-Verlag, 2008. 427 p. ISBN 978-3- 540-77714-4.
Huang J.-L., Zhou K.-Y., Xu J.-Q., Xu X.-H. and Xie J.-W. Failure evaluation of steam-side oxide scales in superheater tubes during unsteady thermal processes: A probabilistic method. Materials and Corrosion. 2014. Vol. 65, Is. 12. P. 1151– 1161. https://doi.org/10.1002/maco.201307338.
Speicher M., Hueggenberg D., Klenk A., Zickler S., Metzger K. Materials for Advanced Ultra-Supercritical Fossil-Fuel Power Plants: Materials Properties, Microstructure, and Component Behavior. Energy Technology. 2015. Vol. 4, Is. 1. P. 187–192. https://doi.org/10.1002/ente.201500311.
Movahedi-Rad A., Plasseyed S. S., Attarian M. Failure analysis of superheater tube. Engineering Failure Analysis. 2015. Vol. 48. P. 94–104. https://doi.org/10.1016/j.engfailanal.2014.11.012.
Tibba G. S., Altenbach H. Modelling Creep Behaviour of Superheater Materials. Energy Procedia. 2016. Vol. 93. P. 197– 202. https://doi.org/10.1016/j.egypro.2016.07.170.
Abang R., Weiß S., Krautz H. J. Impact of increased power plant cycling on the oxidation and corrosion of coal-fired superheater materials. Fuel. 2018. Vol. 220. P. 521–534. https://doi.org/10.1016/j.fuel.2018.02.047.
Timoshenko S. and Goodier J. N. Theory of elasticity. New York Toronto London: MCGRAW-HILL BOOK COMPANY, Inc., 1947. 506 p.
Timoshenko S. Strength of Materials. Part II: Advanced theory and problems. Toronto New York London: D. VAN NOSTRAND COMPANY, Inc., 1940. 510 p.
Betten J. Creep mechanics. Berlin Heidelberg: Springer-Verlag, 2008. 367 p. ISBN 3-540-23204-4.
Lemaitre J., Desmorat R. Engineering damage mechanics. Ductile, creep, fatigue and brittle failures. Berlin Heidelberg New York: Springer, 2005. 394 p. ISBN 3-540-21503-4.
Антикайн П. А. Коррозия металла парогенераторов. Москва: Энергия, 1977. 112 с.
Morachkovskii O. K. and Romashov Yu. V. Solving initialboundary-value creep problems. International Applied Mechanics. 2009. Vol. 45, No. 10. P. 1061–1070. https://doi.org/10.1007/s10778-010-0247-y.
Ромашов Ю. В., Поволоцкий Э. В. Анализ подходов к оценке работоспособности оболочек стержневых твэлов энергетических ядерных реакторов с учетом ползучести. Вісник НТУ «ХПІ». Серія: Енергетичні та теплотехнічні процеси й устаткування. Харків: НТУ«ХПІ», 2018. № 11(1287). С. 63–66. ISSN 2078-774X. doi: 10.20998/2078- 774X.2018.11.10.
Schiesser W. E. Method of Lines Analysis of Turing Models. New Jersey: World Scientific, 2017. 254 p. ISBN 9789813226692
