Design of non-imaging solar collectors for process heat

In this article, a comprehensive optical analysis of a non-imaging elliptical hyperbolic concentrating collector has been carried out. This collector system has a wide acceptance angle so that it can be operated with no/minimum tracking based on the location of operation. Two types of receivers say flat and trapezoidal surface are considered and the flux distribution over these receivers are estimated and compared. It is found that maximum peak flux is intercepted by the trapezoidal surface receiver. The effect of concentrator geometrical parameters such as concentrator height (Hc) and concentration ratio (CR); receiver geometrical parameters such as aperture width (Wr) and receiver height (Hr) on optical performance of the collector has been studied. The optical efficiency varies between 5-15 % for the concentrators with height less than 1 m whose acceptance angle is about 60°, whereas for the concentrator height greater than 1m, the acceptance angle is +45° and the optical efficiency varies between 20-30 % for incidence angles +30°. The maximum flux incident on the trapezoidal surface is about 60585 W/m2 however for flat surface, it is 40468 W/m2. Based on the optical analysis, it can be seen that this system can be widely used for applications such as low and medium temperature applications and it requires less/no tracking with wider acceptance angle.