Modelling of heat and flow phenomena occuring in waterwall tubes of boilers for supercritical steam parameters

• Autorzy: Zima W. , Grądziel S. , Cebula A.
• Języki publikacji: EN

Abstrakty

EN

In this paper a mathematical model enabling the analysis of the heat-flow phenomena occurring in the waterwalls of the combustion chambers of the boilers for supercritical parameters is proposed. It is a one-dimensional model with distributed parameters based on the solution of equations describing the conservation laws of mass, momentum, and energy. The purpose of the numerical calculations is to determine the distributions of the fluid enthalpy and the temperature of the waterwall pipes. This temperature should not exceed the calculation temperature for particular category of steel. The derived differential equations are solved using two methods: with the use of the implicit difference scheme, in which the mesh with regular nodes was applied, and using the Runge-Kutta method. The temperature distribution of the waterwall pipes is determined using the CFD. All thermophysical properties of the fluid and waterwall pipes are computed in real-time. The time-spatial heat transfer coefficient distribution is also computed in the on-line mode. The heat calculations for the combustion chamber are carried out with the use of the zone method, thus the thermal load distribution of the waterwalls is known. The time needed for the computations is of great importance when taking into consideration calculations carried out in the on-line mode. A correctly solved one-dimensional model ensures the appropriately short computational time.

Słowa kluczowe

EN

distributed parameters; Implicit difference scheme; mathematical model; supercritical parameters; waterwalls

PL

ekran wodny; model matematyczny; parametry nadkrytyczne; parametry rozłożone; schemat różnicowy

• Wydawca: Wydawnictwo Instytutu Maszyn Przepływowych PAN ; Komitet Termodynamiki i Spalania PAN
• Czasopismo: Archives of Thermodynamics
• Rocznik: 2010
• Tom: Vol. 31, no. 3
• Strony: 19--31
• Opis fizyczny: Bibliogr. 27 poz.,Rys., tab., wykr., wz.

Twórcy

autor

Zima W.

autor

Grądziel S.

autor

Cebula A.

• Cracov University of Technology, Department of Thermal Power Engineering, Jana Pawła II 37, 31-864 Kraków, Poland,

Bibliografia

• [1] Taler J.: Dynamics of Steam Generators with Natural Circulation Accounting Thermal Stresses. Cracow University of Technology, Cracow 1987 (in Polish).
• [2] Taler J., Duda P.: Solving Direct and Inverse Heat Conduction Problems, Springer, Berlin 2006.
• [3] Zima W.: Mathematical model of transient processes in steam superheaters. Forschung im Ingenieurwesen 68, Springer, Berlin Heidelberg 2003, 51–59.
• [4] Zima W.: Simulation of dynamics of a boiler steam superheater with an attemperator. Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 220(2006), 793–801.
• [5] Zima W.: Mathematical modelling of transient processes in convective heated surfaces of boilers. Forschung im Ingenieurwesen 71, Springer, Berlin Heidelberg 2007, 113–123.
• [6] Grądziel S., Zima W., Cebula A.: Modelling of the transient heat transfer occurring on heated surfaces of boilers. Archives of Energetics 1-2(2007), 53–60 (in Polish).
• [7] Profos P.: Dynamics of Superheater Control. Combustion 31(1959).
• [8] Profos P.: Die Regelung von Dampfanlagen. Springer Verlag, Berlin 1962 (in German).
• [9] Krzyżanowski J.A., Głuch J.: Heat-flow diagnostics of energy objects. IMP PAN, Gdansk 2004 (in Polish).
• [10] Fluent 6.0. Computational fluid dynamics software. Fluent Inc., Lebanon, NH, USA 2006.
• [11] Bertin J. J.: Aerodynamics for Engineers, 4th edn. Prentice Hall, New Jersey 2002.
• [12] Thermodynamic and Transport Properties of Steam. ASME Steam Tables, 6th edn., USA 1993.
• [13] Properties of water and steam using the 1967 IFC formulation for industrial use. American Society of Mechanical Engineers, 1992.
• [14] VDI-Warmeatlas. Springer-Verlag Berlin and Heidelberg GmbH & Co. K., 2006.
• [15] Water & Steam. IAPWS-IF97, Springer-Verlag, 1999.
• [16] Wegst C.W.: Stahlschlüssel. Verlag Stahlschlüssel Wegst GMBH, 2001 (in German).
• [17] Bishop A.A., Sandberg R.O., Tong L.S.: Forced convection heat transfer to water at near-critical temperature and supercritical pressures. Joint Meeting of the American Institute of Chemical Engineers and the British Institution of Chemical Engineers, London 1964.
• [18] Griem H.: A new procedure for the prediction of forced convection heat transfer at near– and supercritical pressure. Heat and Mass Transfer 31(1996), 301–305.
• [19] Kitoh K., Koshizuka S., Oka Yo.: Refinement of transient criteria and safety analysis for a high temperature reactor cooled by supercritical water. In: Proceedings of the Seventh International Conference on Nuclear Engineering (ICONE-7), Tokyo, April 19–23, 1999, Paper No. 7234.
• [20] Loewenberg M.F., Laurien E., Class A., Schulenberg T.: Supercritical water heat transfer in vertical tubes. Progress in Nuclear Energy 50(2008), 532–538.
• [21] Yu J., Jia B., Wu D., Wang D.: Optimization of heat transfer coefficient correlation at supercritical pressure using genetic algorithms, Heat Mass Transfer 45(2009), 757–766.
• [22] Yu J., Liu H., Jia B.: Sub-channel analysis of CANDU-SCWR and review of heat transfer correlations. Progress in Nuclear Energy 51(2009), 246–252.
• [23] Kuznetsov N.W., Nitor W.W., Dubovski I.E. and Karasina E.S.: Thermal Calculations of Steam Boilers. Standard Method, Energy, Moscow 1973 (in Russian).
• [24] Gerald C.F., Wheatley P.O.: Applied Numerical Analysis. Addison-Wesley Publishing Company, New York 1994.
• [25] Fortran PowerStation 4.0. Microsoft Developer Studio, Microsoft Corporation 1994-95.
• [26] Serov E.P., Korolkov B.P.: Dynamics of steam generators. Energia, Moscow 1981 (in Russian).
• [27] Orłowski P., Dobrzański W., Szwarc E.: Steam boilers — structure and calculations. WNT, Warsaw 1979 (in Polish).