Factors determining the durability of steam superheater chambers

• Autorzy: Mutwil K. , Lisok J.
• Języki publikacji: EN

Abstrakty

EN

Purpose: The paper presents the results of calculations of effort for the material of selected superheater chambers' constructional systems in unsteady operation conditions. Design/methodology/approach: In model tests, the influence was analysed of internal pressure and temperature gradient in the chamber wall on the distribution and value of stress. In the calculations, the process of hot start-up of a boiler was simulated, which was accompanied by short thermal shock induced by rapid cooling of the chamber inner wall. Findings: The random nature of thermal shock, which in the industrial practice may occur in any row and to any number of coil pipes, determines the value of maximal stress and the area of its occurrence. It has a significant influence on the possibility of forecasting the durability of chambers in working conditions. Research limitations/implications: The research has evidenced a link between the method of forcing thermal shock and the value of maximal stress in the area of bridges. Practical implications: The research has demonstrated the existence of connection between the way of forcing thermal shock and the stress value which, depending on the variant of cooling the chamber, ranges between 150-370 MPa. These results are very important to the industry connected with the structure of pipelines. Originality/value: It was found that the primary reason for the superheater chamber damage, leading to crack formation, are thermal shocks. A link has been shown between the method of forcing the thermal shock and the value of maximal stress in the zone of bridges.

Słowa kluczowe

EN

outlet chamber of steam superheater; intermediate pipelines; attemperators; discrete superheater model; nal systems in unsteady operation conditions

PL

podgrzewacz pary; rurociąg

• Wydawca: International OCSCO World Press
• Czasopismo: Archives of Materials Science and Engineering
• Rocznik: 2008
• Tom: Vol. 34, nr 1
• Strony: 43--47
• Opis fizyczny: Bibliogr. 15 poz.

Twórcy

autor

Mutwil K.

autor

Lisok J.

• Department of Process Modelling and Medical Engineering, Faculty of Materials Science and Metallurgy, Silesian University of Technology, ul. Krasińskiego 8, 40-019 Katowice, Poland,

Bibliografia

• [1] E. Zbroińska, J. Dobosiewicz, Damages of steam boilers’ superheater header, Power Engineering 3 (1993) 97 (in Polish).
• [2] J. Dobosiewicz, Superheater chambers deflection, Power Engineering 10 (1995) 459 (in Polish).
• [3] S. Kocańda, Fatigue destruction of metals, WNT, Warsaw, 1978 (in Polish).
• [4] J. Dietrych, S. Kocańda, W. Korewa, Fundamentals of machine construction, WNT, Warsaw, 1971 (in Polish).
• [5] K. Mutwil, M. Cieśla, Estimation of superheater header strenuous in steady-state conditions of power boilers, Proceedings of the 7th Scientific International Conference “Computer Aided Engineering”, Polanica Zdrój, 2004 (in Polish).
• [6] A. Hernas, J. Dobrzański, Durability and destruction of boilers and steam turbines’ elements, Silesian University Press, Gliwice, 2003 (in Polish).
• [7] E. Rusiński, T. Smolnicki, J. Wyszyński, Numerical simulation of the effort of the second stage superheater header in the boilers of Power Plant ‘Turów’, Mechanical Review 5-6 (1999) 30-34 (in Polish).
• [8] K. Mutwil, M. Cieśla, Constructional and operational conditions of steam superheater chambers cracking processes, Materials Engineering 28/6 (2007) 914-919 (in Polish).
• [9] T. Wróblewski, A. Pepłowski, H. Górecki, Boiler equipments, PWN, Warsaw, 1970 (in Polish).
• [10] A. Waynman, Modern state of the problem of hydrogen embitterment of metal of TPP thermo-mechanical equipment of pre-and overcritical parameters, Proceedings of the 3rd International Conference “Facture mechanics of materials and structural integrity”, Lviv, 2004.
• [11] C.C. Spyrakos, Finite Element Modeling in Engineering Practice, West Wirginia University Press, Morgantown, 1994.
• [12] K. Mutwil, M. Cieśla, J. Okrajni, J. Lisok, Forecasting of residual durability of power industry objects by the use of numerical modeling, Surface Mining 50/4-5 (2008) 141-147 (in Polish).
• [13] T. Hobler, Thermal motion and exchangers, WNT, Warsaw, 1956 (in Polish).
• [14] A. Wocławski, Steels characteristics, Series D, Steels operating in elevated and reduced themperatures, Vol. 1, Part 2, Steels for power industry, Śląsk, Katowice, 1984 (in Polish).
• [15] J. Czmochowski, A. Górski, A. Iluk, J. Wyszyński, Numerical strength analysis steam superheater of the power boiler, Proceedings of the 6th Scientific International Conference “Computer Aided Engineering”, Polanica Zdrój, 2002 (in Polish).