Modeling of warm-keeping process with hot air in steam turbines

• Autorzy: Łuczyński P. , Többen D. , Wirsum M. , Mohr W.F.D , Helbig K.
• Języki publikacji: EN

Abstrakty

EN

Steam turbines in conventional power plants have to deal with an increasing number of start-ups due to the high share of fluctuating power input in renewable power generation. As a result, the development of new methods for flexibility improvements - such as reductions in start-up time and the effects these start-ups have on turbine lifetime - have become increasingly important. In pursuit of this objective, General Electric has developed a concept for both the pre-warming and warm-keeping of a high-pressure (HP) / intermediate-pressure (IP) steam turbine with hot air: hot air is passed through the turbine while the turbine is rotated by the turning engine. Due to the high impact of transient flow phenomena on heat transfer during turbine warm-keeping operations, the reliable modeling of the time-dependent temperature distribution within thick-walled components is required as a tool for the optimization of these operations. Due to the extremely high computational effort required for conventional transient Conjugate Heat Transfer (CHT) simulations, alternative fast calculation approaches must be developed. The applied methodology for modeling warm-keeping turbine operations with hot air is presented in this paper. Furthermore, the key modeling steps have been analyzed. A fast transient CHT simulation approach called the Equalized Timescales (ET) method was developed to investigate heat transfer in the fluid and blades. Moreover, the setup of ET simulations was optimized with regard to accuracy and computing time. As a result, several operating points characterizing the turbine warm-keeping operational range were calculated for a single stage model. A sensitivity analysis regarding the heat transfer between fluids and solids was conducted to identify the most relevant surfaces. The ET method was then expanded to a numerical 3-stage turbine model in order to determine a HTC characteristic map for heat transfer in warm-keeping operations. This enables fast calculation of heat transfer rates and, consequently, computationally efficient determination of temperature distribution in warm-kept steam turbines. For comparison, the distribution of HTC was additionally calculated for one operating point of a 5-stage turbine model. Finally, the contact heat transfer in blade roots, which is believed to have a high impact on the temperature distribution of the rotor, was experimentally assessed in a test rig. The description of the test rig and the methodology of determination of the thermal contact resistance (TCR), as well as the impact of TCR on the temperature distribution in the rotor are presented.

Słowa kluczowe

EN

district heating networks; heat cost; pipe diameter; graph theory

PL

sieci ciepłownicze; koszty ogrzewania; średnica rury; teoria grafów

• Wydawca: Institute of Heat Engineering, Warsaw University of Technology
• Czasopismo: Journal of Power Technologies
• Rocznik: 2017
• Tom: Vol. 97, nr 5
• Strony: 416--428
• Opis fizyczny: Bibliogr. 25 poz., rys., wykr.

Twórcy

autor

Łuczyński P.

• Institute for Power Plant Technology, Steam and Gas Turbines, RWTH Aachen University, Templergraben 55, 52062 Aachen, Germany

autor

Többen D.

• Institute for Power Plant Technology, Steam and Gas Turbines, RWTH Aachen University, Templergraben 55, 52062 Aachen, Germany

autor

Wirsum M.

• Institute for Power Plant Technology, Steam and Gas Turbines, RWTH Aachen University, Templergraben 55, 52062 Aachen, Germany

autor

Mohr W.F.D

• General Electric (Switzerland) GmbH, Brown Boveri Str. 7, 5401 Baden, Switzerland

autor

Helbig K.

• GE Power AG, Boveristraße 22, 68309 Mannheim, Germany

Bibliografia

• [1] H. Wirth, K. Schneider, Recent facts about photovoltaics in germany, Fraunhofer ISE (2015) 92.
• [2] J. Vogt, T. Schaaf, W. Mohr, K. Helbig, Flexibility improvement of the steam turbine of conventional or ccpp, Power-Gen Europe, Cologne, Germany, June (2013) 4–6.
• [3] S. Flake, et al., Using stream turbine warming blankets to reduce startup time and rotor stress, Power 160 (3) (2016) 14–17.
• [4] J. Spelling, M. Jöcker, A. Martin, Thermal modeling of a solar steam turbine with a focus on start-up time reduction, Journal of engineering for gas turbines and power 134 (1) (2012) 013001.
• [5] M. Topel, M. Genrup, M. Jöcker, J. Spelling, B. Laumert, Operational improvements for startup time reduction in solar steam turbines, Journal of Engineering for Gas Turbines and Power 137 (4) (2015) 042604.
• [6] K. Helbig, C. KÜHNE, W. Mohr, A warming arrangement for a steam turbine in a power plant, eP Patent App. EP20,120,195,309 (Jun. 4.2014).
• [7] L. He, M. Oldfield, Unsteady conjugate heat transfer modeling, Journal of turbo machinery 133 (3) (2011) 031022.
• [8] D. Toebben, P. Łuczyński, M. Diefenthal, M. Wirsum, S. Reitschmidt, W. F. Mohr, K. Helbig, Numerical investigation of the heat transfer and flow phenomena in an ip steam turbine in warm-keeping operation with hot air, in: ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition, American Society of Mechanical Engineers, 2017, pp. V008T29A014–V008T29A014.
• [9] M. Diefenthal, P. Łuczyński, C. Rakut, M. Wirsum, T. Heuer, Thermomechanical analysis of transient temperatures in a radial turbine wheel, Journal of Turbomachinery 139 (9) (2017) 091001.
• [10] M. Diefenthal, P. Łuczyński, M. Wirsum, Speed-up methods for the modeling of transient temperatures with regard to thermal and thermomechanical fatigue, in: 12th European Turbomachinery Conference, 2017.
• [11] D. Bohn, J. Ren, K. Kusterer, Conjugate heat transfer analysis for film cooling configurations with different hole geometries, ASME Paper No. GT2003-38369.
• [12] D. Bohn, T. Heuer, K. Kusterer, Conjugate flow and heat transfer investigation of a turbo charger, Journal of engineering for gas turbines and power 127 (3) (2005) 663–669.
• [13] K. Saunders, S. Alizadeh, L. Lewis, J. Provins, The use of cfd to generate heat transfer boundary conditions for a rotor-stator cavity in a compressor drum thermal model, in: ASME Turbo Expo 2007: Power for Land, Sea, and Air, American Society of Mechanical Engineers, 2007, pp. 1299–1310.
• [14] L. V. Lewis, J. I. Provins, A non-coupled cfd-fe procedure to evaluate windage and heat transfer in rotor-stator cavities, ASME Paper No. GT2004-53246.
• [15] M. Diefenthal, C. Rakut, H. Tadesse, M. Wirsum, T. Heuer, Temperature gradients in a radial turbine in steady state and transient operation, in: International gas turbine conference, Tokyo, Japan, 2015.
• [16] H. D. Baehr, K. Stephan, Wärme-und stoffübertragung, Wärme-und Stoffübertragung:, ISBN 978-3-642-05500-3. Springer-Verlag Berlin Heidelberg, 2010.
• [17] D. Többen, X. E. R. de Graaf, P. Łuczyński, M. Wirsum, W. Mohr, K. Helbig, Test rig for applied experimental investigations of the thermal contact resistance at the blade-rotor-connection in a steam turbine, ISROMAC.
• [18] M. M. Yovanovich, Four decades of research on thermal contact, gap, and joint resistance in microelectronics, IEEE transactions on components and packaging technologies 28 (2) (2005) 182–206.
• [19] H. Fenech, W. Rohsenow, Prediction of thermal conductance of metallic surfaces in contact, journal of Heat Transfer 85 (1) (1963) 15–24.
• [20] B. B. Mikic, W. M. Rohsenow, Thermal contact resistance, National Aeronautics and Space Administration,.
• [21] M. M. Yovanovich, H. Fenech, Thermal contact conductance of nominally flat, rough surfaces in a vacuum environment, Thermophysics and Temperature Control of Spacecraft and Entry Vehicles 18 (1966) 773–794.
• [22] M. Cooper, B. Mikic, M. Yovanovich, Thermal contact conductance, International Journal of heat and mass transfer 12 (3) (1969) 279–300.
• [23] C. V. Madhusudana, Thermal contact conductance.
• [24] V. Ustinov, R. Kneer, F. Al-Sibai, S. Schulz, E. El-Magd, Influence of surface roughness on contact heat transfer, in: 2010 14th International Heat Transfer Conference, American Society of Mechanical Engineers, 2010, pp. 305–312.
• [25] V. Ustinov, S. G. Schulz, R. Kneer, E. El-Magd, Model development for the contact pressure dependent heat transfer, MTZ worldwide 79 (9) (2011) 48–53.

Uwagi

PL

Opracowanie rekordu w ramach umowy 509/P-DUN/2018 ze środków MNiSW przeznaczonych na działalność upowszechniającą naukę (2018).