Optical design of a tension cable-membrane concentrator

Abstract

This paper proposes a Tension Cable-Membrane Concentrator with an ultra-lightweight, practical and low cost alternative construction which is used in the optical-electrical conversion system. The relationship between the varied count triangular facets of the membrane surface and the focal spot radius are studied. Based on Monte Carol ray-tracing method, the optical performances of the concentrator, such as the concentrate ratio, flux distributions and focal spot radiuses etc., are analyzed in different geometry design parameters. Further, a 15 m aperture Tension Cable-Membrane Concentrator is designed, and the form-finding design is studied and verified by ANSYS®. The optical performance comparisons with the original and pre-stressed shape of the reflective film are discussed. Simulation results exhibit that the surface density of the proposed Tension Cable-Membrane Concentrator is only 5% of that of traditional rigid concentrator. It takes on the ultra-lightweight and low-cost that excite designers. The optical performance comparisons show that the peak flux distribution after form-finding over a 0.25 m receiver approximately deliver up to 800 kW/m2 corresponding to the peak concentrate ratio exceeds 1000 suns which are even better than the traditional steel design and completely satisfy design requirements.

Keywords

• Solar concentrator
• Stretched membrane
• Triangular facets
• Form-finding
• Optical design