Design of a Scheffler Mosaic Mirror by Optical Raytracing and CAD Software

Abstract

The Scheffler reflector is a parabolic metal concentrator, typically applied in solar thermal systems with receiver fixed to the ground. The Scheffler mirror is deformed during the year to optimize its solar light collection. For practical reasons it is useful to manufacture such a curve reflector as mosaic mirror. This study develops a configuration of the mosaic mirror type starting from the continuous mirror, trying to indicate how the reflector can be designed. Combining a CAD software tool with raytracing simulations, the optical performance of the Scheffler mosaic mirror is compared with a continuous Scheffler collector. The CAD software reproduces the mechanical deformations of a real Scheffler reflector; while the raytracing software simulates the image that the Scheffler reflector concentrates on the receiver. However, the characteristics of the final composed reflector must be revised depending on the receiver requirements. Moreover, the sizing of the elementary mirrors must be chosen considering the final receiver and it also depends on economic considerations.