Optimization of Solar Updraft Chimneys by Nonlinear Response Analysis

Abstract:

Solar updraft chimneys (SUCs) form as engines of solar updraft power plants tower-like shell structures of extreme height with rather thin shell walls, similar to high chimneys comprising multiple flue gas ducts. The height of pre-designed SUCs presently reaches up to 1000 m. Thus they are exposed chiefly to extreme wind-loads and thermal actions from the internal flow of warm air. As first design attempt, the structural analysis of solar chimneys generally is carried out by linear elastic models. For optimization, the typical shell-like wind stresses have to be constraint towards a more beam-like response behavior, approaching as far as possible linear stresses over the entire chimney circumference. This requires rather strong ring stiffeners, either as spoke-wheels in the designs of sbp (Schlaich Bergermann and Partners) or as external stiffeners in the designs of K&P (Krätzig and Partners). Both alternatives require considerable construction efforts leading to high investment costs. There exists an interesting simplification of this stiffening, namely applying to the SUC shell relatively soft external rings, and admitting large-widths cracking in the limit state of failure. This cracking constraints and equalizes the meridional stresses over the chimney’s cross-section, saving large amounts of reinforcement steel in the SUC. The design requires materially nonlinear analyses to verify the internal forces under crack-formations. The manuscript will derive this concept and demonstrate the crack analysis by example of a 750 m high solar chimney.

• Periodical: Applied Mechanics and Materials (Volume 283)
• Pages: 25-34
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.283.25
• Online since: January 2013
• Authors: Reinhard Harte, Martin Graffmann, Wilfried B. Krätzig
• Keywords: Materially Non-Linear Analyses, Minimum Reinforcement Steel, Ring-Stiffened Shells, Solar Chimney, Solar Updraft Power Plants

References

[1] Th.W. von Backström, R. Harte, R. Höffer, W.B. Krätzig, D.G. Kröger, H. -J. Niemann and G.P.A.G. van Zijl:. State and Recent Advances in Research and Design of Solar Chimney Power Plant Technology. VGB PowerTech. Vol. 88 (2008), 7, pp.64-71.

[2] D. Busch, R. Harte, W.B. Krätzig and U. Montag: New Natural Draft Cooling Tower of 200 m of Height. IABSE Journal of Engineering Structures Vol. 22 (2002), pp.107-109.

DOI: 10.1016/s0141-0296(02)00082-2

[3] J. Form, W. Krings, H. Mazur and H.L. Peters: Berechnung und Ausführung eines ringversteiften Naturzugkühlturms (in German). Beton- u. Stahlbetonbau 75 (1980), pp.205-212.

DOI: 10.1002/best.198000350

[4] Ph.L. Gould and W.B. Krätzig: Cooling Tower Structures. In: W. -F. Chen, E.M. Lui (eds. ), Handbook of Structural Engineering, p.27/1-27/41, CRC Press, Boca Raton (2004).

[5] M. Graffmann, R. Harte, W.B. Krätzig and U. Montag: Sturmbeanspruchte dünne Stahlbetonschalen im Ingenieurbau. In: P. Mark, M. Strack (Eds. ), Fünf Jahrzehnte in Forschung, Lehre und Praxis, pp.183-195, Ruhr-University Bochum (2007).

[6] R. Harte, W.B. Krätzig, U. Montag and Y.S. Petryna: Damage, rehabilitation and residual life duration of natural draft cooling towers. VGB PowerTech, Vol. 85 (2005) 6, pp.61-66.

[7] W.B. Krätzig, R. Harte, U. Montag and R. Wörmann: From large natural draft cooling tower shells to chimneys of solar upwind power plants. In: A. Domingo, C. Lazaro (eds. ), IASS Symposium on Evolutions and Trends in Design, Analysis and Construction of Shells and Spatial Structures. CD-Rom, University of Valencia (2009).

DOI: 10.1061/41031(341)105

[8] W.B. Krätzig, R. Harte, L. Lohaus and U. Wittek: Naturzugkühltürme (Natural draft cooling towers), Chapter X, Betonkalender 2007/2, pp.231-322, Ernst & Sohn, Germany, Berlin (2007).

DOI: 10.1002/9783433600696.ch10

[9] W.B. Krätzig and Y. S. Petryna: Assessment of structural damage and failure. Arch. of Appl. Mechanics, Vol. 71 (2001), pp.1-15.

[10] W.B. Krätzig. Multi-level modeling techniques for elasto-plastic structural responses. In D. Owen et al. (eds. ) Computational Plasticity, Proc. 5th Intern. Conf., Part 1: pp.457-468. Barcelona: CIMNE-Intern. Center for Numerical Methods in Engineering (1997).

[11] W.B. Krätzig: Naturzugkühltürme - Erreichen wir eine Wachstumsgrenze? In: H. Glubrecht (Hrg. ), Kraftwerksbau als interdisziplinäre Aufgabe. Bauverlag GmbH., Germany, Wiesbaden (1973).

[12] F. Lupi: Structural behaviour, optimization and design of a solar chimney prototype under wind loading and other actions. Master Thesis, Università degli studi di Firenze (2011).

[13] J. Schlaich, R. Bergermann, W. Schiel and G. Weinrebe: Design of Commercial Solar Updraft Tower Systems. Journal of Solar Energy Engineering, Vol. 127 (2005), pp.117-124.

DOI: 10.1115/1.1823493

[14] J. Schlaich: The Solar Chimney, Electricity from the Sun. Edition A. Menges, Stuttgart, Germany (1995).

[15] VGB-610 Ue. Structural Design of Cooling Towers, Technical Guideline for the Structural Design, Computation, and Execution of Cooling Towers", VGB Kraftwerkstechnik (PowerTech), Germany, Essen (2010).

DOI: 10.1201/b17001-36