Stand-alone Solar Reflector Dish
University of Stellenbosch
Rohan Meyer (Undergraduate BEng Mechanical)
Supervisor: Mr Robert Dobson
Energy Postgraduate Conference 2013
How “enginerds” are characterized:
Contents
1) Common designs
2) Our Design Philosophy
3) Our Design
4) Wind loading
5) Beam theory
6) Software theory: MSC Nastran and SimXpert 2011
7) Results
8) Experimental testing
9) The way forward
10) Conclusions and Recommendations
11) Acknowledgements
12) References
Common designs
Source: www.solarenergytopics.com
McDonnell-Douglas
- 12 kWe Stirling dish
- Weight of reflector and
receiver balance on pivot
point
Source: www.cliquesolar.com
Heliofocus design(linear Fresnel)
-
Flat surface with tilted mirrors
Equivalent of Fresnel dish concept
Similar to Solar Tower Heliostat, but
single dish frame
Common designs(continued)
Source: www.titantracker.com
Source: www.xaharts.org
German Eurodish
-
17m diameter, 50kWe
Spanish titan
- 3.2m diameter double dish
Our Design Philosophy
• Cheap! Because less is more.
• Assembly of structure: Think of a camping tent!
• Light weight, but durable and strong.
• The consequence: Rural Africans can assemble their own
power source in their back yard, for next to nothing.
Our design (G. Prinsloo, R. Meyer)
Wind loading
Beam theory
Software theory
MSC Nastran and SimXpert 2011
CBEAM Element geometry in SimXpert
PSHELL CQUAD4 Element in
SimXpert
L-shaped beam cross section
Structure analysed using beam
elements for spokes and bars and
shell elements for middle-flange.
Results(Intuitive model)
• Displacement
Results(continued)
• Torsion due to asymmetric section
Results(continued)
• Maximum combined beam stresses
Experimental testing
• Aluminum strain gauges to measure strain and
displacement. Top and bottom of flat surface for bending, 2
x 45° for “torsion” of a asymmetric L-shaped section.
The way forward
• Added aluminum plates with reflective material in
software simulation. Adds to stiffness and mass matrix of
model.
• Dynamic analysis of structure with wind loading varying
with time.
• Experimental testing
Conclusions and Recommendations
•
•
•
•
•
•
Knowledge on response of structure – future simulations
Easily assembled, stand-alone solar reflector
Possible SKA power source
Renewable energy, replacing sources like nuclear and coal
Solar power to rural African communities
Moral of the story: Always take the motorcycle, because the
clothes won’t fit.
Acknowledgements
• A million thank you’s goes out to Mister Dobson for his
supervision, advice and funding of the research I am doing.
• My sincere appreciation goes out to Mister Gerro Prinsloo,
MSc Mech student, for his astonishing work he is doing on the
design, construction and testing of a self-tracking solar
concentrating reflector and his helpful advice with my
research.
• It is an honour working with people that has faith in
Renewable Energy and that are doing fascinating research in
this field.
References
Cengel, Y. A. & Cimbala, J. M., 2010. Fluid Mechanics Fundamentals
and Applications. Second Edition in SI Units ed. Asia: McGraw-Hill
Education.
Cook, R. D., Malkus, D. S., Plesha, M. E. & Witt, R. J., 2002.
Concepts and Applications of Finite Element Analysis. Fourth
Edition ed. United States: John Wiley & Sons Inc..
MSC, 2012. MSC SimXpert. [Online]
Available at: https://www.mscsoftware.com/product/simxpert
[Accessed 12 March 2013].
Thank you very much!
Rohan Meyer