Solar concentrator of segmented heliostat and a Fresnel lens for sun tracking applications

Abstract

Concentrating solar power systems (CSP) are used on applications that require high temperatures and are often paired to a tracking system capable to align the position of the concentrating surface according to that of the sun. In order to achieve this, movable structures capable of supporting the optical surface while resisting wind loads are required, which increases the cost of the concentrating system. The objective of this research is to propose a novel solar furnace with a segmented heliostat in order to reduce the impact of wind loads over its surface. The proposed system is comprised by a two-axis segmented heliostat tracker, a vertical fixed Fresnel lens and a spot-type receiver. Its performance was analyzed in terms of two effects caused by the elements' configuration: blocking and screening. Both effects were characterized through a mathematical model in order to maximize the intercepted solar radiation by means of finding the optimal distance between the heliostats’ segments and the relative Fresnel lens area to the array. The performance of the system was tested by means of optical simulations and wind load analysis.