Optical and thermal performance of a toroidal compound parabolic concentrator.

The design, construction, and ray simulation of a new compound parabolic concentrator based on a toroidal shape (toroidal compound parabolic concentrator, TCPC) are addressed. Such analysis indicates that the amount of concentrated radiation is independent of the Sun trajectory. Thus, the TCPC has the advantage of concentrating Sun rays in a spot, and if positioned with an inclination corresponding to the latitude, a solar tracker would not be needed. Experimental measurements with a prototype model are shown to be in good agreement with the simulation results. The possibility of a variety of applications, as natural illumination for this TCPC device, is also pointed out. The simple design, fabrication, and implementation of the TCPC make it an excellent alternative for low concentration in a spot. We present the analysis of the TCPC in natural illumination as one of these applications.