Design of free-form trough reflector for solar thermal concentrator system based on quadratic Bézier curves

Abstract

An optimization method based on the mathematical theory of quadratic Bézier curves is proposed for the design of a free-form trough (FF) reflector in a solar concentrator system. Notably, the continuity (or discontinuity) of the surface generated by the proposed method is almost completely independent of the source-target mapping function. It is shown that the proposed method requires only a small number of structural points to approach the optimal design solution. The ZEMAX simulation results show that, compared with traditional cylindrical and parabolic trough concentrators, the FF concentrator yields an effective improvement in the irradiance uniformity on the heat pipe surface. Notably, the proposed method adopts a purely algebraic approach and is hence easily implemented in computer code.