Engineering Transactions, 67, 4, pp. 579–591, 2019
10.24423/EngTrans.896.20191210

The Impact of Temperature Oscillations and Heat Transfer Conditions in Thick-Walled Elbows and Tubes on the Local Stress-Strain Behaviour During the Fast Start-Up of Power Boilers

Jerzy OKRAJNI
Silesian University of Technology
Poland

Krzysztof WACŁAWIAK
Silesian University of Technology
Poland

The paper presents results of tests designed for predicting the behaviour of components subjected to variable temperature and mechanical loading conditions. Elbows and tubes, as examples of components widely used in power plant pipelines, have been examined. This analysis includes a description of model characteristics, the operating parameters of devices under industrial conditions, and the results of computational modelling (FEM).
Keywords: stress-strain behaviour; thermo-mechanical fatigue; thick-walled elements; numerical simulation; heat transfer
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Copyright © The Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0).

References

Farragher T.P., Scully S.O., O’Dowd N.P., Leen S.B.: Development of life assessment procedures for power plant headers operated under flexible loading scenarios, International Journal of Fatigue, 49: 50–61, 2013, doi: 10.1016/j.ijfatigue.2012.12.007.

Okrajni J., Twardawa M.: Local strains that lead to the thermo-mechanical fatigue of thick-walled pressure vessels, Materials Performance Characterization, 3(2): 245–261, 2014, doi: 10.1520/MPC20130059.

Farragher T..P, Scully S., O’Dowd N.P., Leen S.B.: Thermomechanical analysis of pressurized pipe under plant conditions, ASME Journal of Pressure Vessels Technology, 135(1): 011204, 2012, doi: 10.1115/1.4007287.

Okrajni J., Twardawa M.: Boundary conditions in models of power plant components under thermal loading, Archives of Materials Science and Engineering, 62(1): 28–35, 2013.

Okrajni J., Twardawa M.: Influence of a variable in time heat transfer coefficient on stresses in models of power plant components, ASME Journal of Pressure Vessel Technology, 136(4): 041602, 2014, doi: 10.1115/1.4026799.

ANSYS Elements Reference, Release 11.0, USA, SAS IP, Inc., 2007.

ANSYS Structural Analysis Guide, Release 12.1, USA, SAS IP, Inc., 2009.

Halama, R.; Sedlák, J., Šofer, M.: Phenomenological modelling of cyclic plasticity, Numerical Modelling, Dr. Peep Miidla (Ed.), ISBN: 978-953-51-0219-9, InTech, 2012, doi: 10.5772/35902.

PN-EN 12952-4:2002: Water-tube boilers and ancillary equipment - Part 4: Calculations of the expected durability of boilers during operation [in Polish: Kotły wodnorurowe i urządzenia pomocnicze – Część 4: Obliczenia oczekiwanej trwałości kotłów podczas eksploatacji].

Bressers J., Remy L. (Eds): Fatigue under thermal and mechanical loading, Netherlands: Kluwer Academic Publishers, 1996.

Hähner P., Rinaldi C., Bicego V., Affeld E., Brendel T., Andersson H., Beck T., Klingelhöffer H., Kühn H-J., Köster A., Laveday M., Marchionni M., Rae C.: Research and development into a European code-of-practice for strain-controlled thermo-mechanical fatigue test, International Journal of Fatigue, 30(2): 372–381, 2008, doi: 10.1016/j.ijfatigue.2007.01.052.

Sehitoglu H.: Thermal and Thermo-mechanical Fatigue of Structural Alloys, [in:] Fatigue and Fracture. ASTM Handbook, Vol. 19, pp. 527–556, 2008, doi: 10.31399/asm.hb.v19.9781627081931.

Okrajni J., Plaza M.: Simulation of the fracture process of materials subjected to low-cycle fatigue of mechanical and thermal character, Journal of Material Processing Technology, 53(1–2): 311–318, 1995, doi: 10.1016/0924-0136(95)01988-Q.

Okrajni J., Junak G., Marek A.: Modelling of the deformation process under thermo-mechanical fatigue conditions, International Journal of Fatigue, 30(2): 324–329, 2008, doi: 10.1016/j.ijfatigue.2007.01.043.




DOI: 10.24423/EngTrans.896.20191210