Plane facetted reflectors - Structures and mirror fields
Abstract
General systems theory is used to examine the behavior of solar reflective surfaces from a different point of view than classical optical imaging, and to derive precise methods for focussing, control, and structural stability of fields of mirrors. A 100 kW photothermal conversion plant is considered, which requires a concentration of 350 and a paraboloidal shape. Equilateral triangles are utilized to approximate a paraboloid of revolution. Concentrators with fixed surfaces are noted to contain unequal areas of concentration, and the use of movable facets is shown to allow adjustments of the reflected flux to meet demands. Systems theory is applied for a solar source and a converter and the control logic is outlined. The performance of a curved mirror is demonstrated to be a limited case of a facetted mirror, and application to actual installations is shown to be a matter of topological analysis to determine the zones of stable and complete irradiation and partial irradiation.
- Publication:
-
Cooperation Mediterraneenne pour l'Energie Solaire
- Pub Date:
- December 1981
- Bibcode:
- 1981cmes.rept...20A
- Keywords:
-
- Mirrors;
- Solar Reflectors;
- Flat Surfaces;
- Fresnel Reflectors;
- Geometrical Optics;
- Paraboloid Mirrors;
- Systems Analysis;
- Energy Production and Conversion