ABSTRACT OF PAPER PREPARED FOR WWEC 2003:
APPLICABLE SUBJECT NUMBER: 8.3 (New concepts)
TITLE: SOLAR CHIMNEYS AS HYBRID WIND-SOLAR POWER PLANTS
AUTHORS: TW von Backström and NA Cencelli
CORRESPONDING AUTHOR:
Prof. Theodor W von Backström
Department of Mechanical Engineering
University of Stellenbosch
Private Bag X1
Matieland 7602
South Africa
Tel: 27 21 8084267
Fax: 27 21 8084958
E-mail:
CO-AUTHOR:
Nicola A Cencelli,
Graduate student
Department of Mechanical Engineering
University of Stellenbosch
SOLAR CHIMNEYS AS HYBRID WIND-SOLAR POWER PLANTS
TW von Backström and NA Cencelli
BACKGROUND AND INTRODUCTION
A proposed 200 MW solar chimney power plant consists of a large (7 km diameter) greenhouse surrounding a tall (1000 to 1500 m high) chimney [1]. Hot air rising in the chimney first passes through a turbine (or turbines). At maximum power production the wind velocity up the chimney is typically 15 m/s and the pressure drop across the turbine is 1000 Pa.
PURPOSE OF THE WORK:
The purpose of the work is to investigate the effect of wind blowing over the top of the chimney on the power production of the chimney.
APPROACH:
The approach is to use available experimental data [2] for cooling towers and apply it to a proposed design of a solar chimney power plant of which other aspects have been investigated.
SCIENTIFIC INNOVATION AND RELEVANCE:
The problem involves the application of scientific knowledge in the fields of solar and wind energy. It turned out that wind might have an effect of the order of 10 % on plant power production. A solar chimney such as the one described may well be the world’s most powerful single wind energy power plant, and the effect of wind on the plant may be significant in terms of the cost and availability of the power produced.
REFERENCES
1. Gannon, AJ and von Backström TW, Solar chimney cycle analysis with system loss and solar collector performance. ASME Journal of Solar Energy Engineering, Vol 122, pp. 133-137, August 2000.
2. Du Preez, A.F., The influence of cross-winds on the performance of natural draft dry-cooling towers. Ph.D. dissertation, Department of Mechanical Engineering, University of Stellenbosch 1992.
Brief CV of TW von Backström
Born in 1945 in Pretoria. Qualified as South African Air Force Pilot (1963). Awarded BSc(Eng)(Mech)c.l. (1967). Completed MSc(Eng)(Mech) degree at University of Pretoria by part time study (1970), and PhD(Eng)(Mech)(1980) at University of Stellenbosch with Prof DG Kröger as promoter, while working full time. Employed at Atomic Energy Corporation and Uranium Enrichment Corporation from 1968 to 1983 on uranium enrichment technology, process fluid mechanics and process turbo-compressor design. Designed transonic axial flow compressor for first South African gas turbine engine. Professor in fluid mechanics at the University of Stellenbosch since 1984, and was Chairman of Department of Mechanical Engineering in 1986, 1992, 1996-1998 and 2001-2002. Enjoyed sabbaticals as respectively visiting scholar, senior scientist and visiting professor at Whittle Laboratory, Cambridge (1988), at Aerospace Engineering, Pennsylvania State University (1995) and at Aeronautical and Aerospace Engineering, Naval Postgraduate School, Monterey, California (1999). Publications are mostly in CFD, turbomachinery and recently in solar and wind energy. Current research interests are design and application of turbomachinery, for example fans, solar chimney and wind turbines and turbochargers.
SELECTED RECENT PUBLICATIONS
1. Von Backström, T.W. and Gannon, A.J., The solar chimney air standard thermodynamic cycle. SAIMechE R&D Journal, volume 16, No. 1, pp. 16 - 24, 2000.
2. Gannon, A.J. and Von Backström, T.W., Comparison of streamline through-flow and streamline-curvature methods. International Journal of Turbo and Jet Engines, volume 17, pp.161 - 170, 2000.
3. Gannon, A.J. and Von Backström, T.W., Solar chimney cycle analysis with system loss and solar collector performance. ASME Journal of Solar Energy Engineering, volume 122, pp. 133 - 137, August 2000.
4. Von Backström, T.W. and Gannon, A.J., Compressible flow through solar power plant chimneys. ASME Journal of Solar Energy Engineering, volume 122, pp. 138 - 145, August 2000.
5. Von Backström T.W., Calculation of pressure and density in solar power plant chimneys. ASME Journal of Solar Energy Engineering, Vol. 125, No. 1, pp. 127-129, February 2003. (Technical Brief).
6. Gannon, A.J. and Von Backström, T.W., Solar chimney turbine performance. ASME Journal of Solar Energy Engineering, Vol. 125, No. 1, pp. 101-106, February 2003.
7. Von Backström T.W., Benhardt, A. and Gannon, A.J., Pressure drop in solar power plant chimneys. Accepted, and proof read for publication in ASME Journal of Solar Energy Engineering, Vol. 125, May 2003.
8. Von Backström T.W. and Gannon, A.J., Solar chimney turbine characteristics, Accepted for publication in the ISES 2001 Conference, Special Proceedings Issue of the Solar Energy Journal, 2003.
Teetz, H.W., Harms, T.M. and Von Backström T.W., Assessment of the wind power potential at SANAE IV base, Antarctica: a technical and economic feasibility study. Accepted for publication in Renewable Energy, 2003.