Determination of temperature and thermal stresses distribution in power boiler elements with use inverse heat conduction method

• Autorzy: Grądziel S.
• Języki publikacji: EN

Abstrakty

EN

The following paper presents the method for solving one-dimensional inverse boundary heat conduction problems. The method is used to estimate the unknown thermal boundary condition on inner surface of a thick-walled Y-branch. Solution is based on measured temperature transients at two points inside the element's wall thickness. Y-branch is installed in a fresh steam pipeline in a power plant in Poland. Determination of an unknown boundary condition allows for the calculation of transient temperature distribution in the whole element. Next, stresses caused by non-uniform transient temperature distribution and by steam pressure inside a Y-branch are calculated using the finite element method. The proposed algorithm can be used for thermal-strength state monitoring in similar elements, when it is not possible to determine a 3-D thermal boundary condition. The calculated temperature and stress transients can be used for the calculation of element durability. More accurate temperature and stress monitoring will contribute to a substantial decrease of maximal stresses that occur during transient start-up and shut-down processes.

Słowa kluczowe

EN

heat transfer coefficient; inverse method; stress distribution; transient temperature

PL

metoda inwersji; propagacja nacisków; szybkozmienna temperatura; współczynnik przenikania ciepła

• Wydawca: Wydawnictwo Instytutu Maszyn Przepływowych PAN ; Komitet Termodynamiki i Spalania PAN
• Czasopismo: Archives of Thermodynamics
• Rocznik: 2011
• Tom: Vol. 32, no. 3
• Strony: 191--200
• Opis fizyczny: Bibliogr. 9 poz.,

Twórcy

autor

Grądziel S.

• Cracow University of Technology, Department of Thermal Power Engineering al. Jana Pawła II 37, 31-864 Krakow, Poland,

Bibliografia

• [1] BECK J.V.: Hanbook of Numerical Heat Transfer. Inverse Problems. John Wiley & Sons, New York 1968.
• [2] CWYNAR L.: Start-up of Steam Boilers. WNT, Warsaw 1981 (in Polish).
• [3] REASON J.: Measure how fast you’re expending boiler life. Power 129(1985), 7, 31–34.
• [4] TALER J., WĘGLOWSKI B., ZIMA W., GRĄDZIEL S., ZBOROWSKI M.: Monitoring of transient temperature and thermal stresses in pressure components of steam boilers. Int. J. Pressure Vessels and Piping 72(1997), 231–241.
• [5] TALER J., GRĄDZIEL S.: An overdetermined two-dimensional transient inverse heat conduction problem. Forschung im Ingenieurwesen 65(1999), 98–106.
• [6] TALER J., GRĄDZIEL S.: Nichtlineares inverses Wärmeleitungsproblem bei der Überwachung von Wärmespannungen. Forschung im Ingenieurwesen 63, 102–111, Springer-Verlag, 1997.
• [7] GRĄDZIEL S.: Identification of the transient thermal state of thick-walled boiler components. Cracow University of Technology, Mechanics 79, Kraków 1997 (in Polish).
• [8] TALER J., WĘGLOWSKI B., ZIMA W., GRĄDZIEL S., ZBOROWSKI M.: Analysis of thermal stresses in a boiler drum during start-up. Trans. ASME J. Pressure Vessel Technology 121(1999), 84–93.
• [9] TALER J., WĘGLOWSKI B., GRĄDZIEL S., DUDA P., ZIMA W.: Monitoring of Thermal Stresses in Pressure Components of Large Steam Boilers. VGB KraftwerksTechnik 1(2002), 73