Theoretical and experimental analysis of an innovative dual-axis tracking linear Fresnel lenses concentrated solar thermal collector

Abstract

Linear concentrating solar thermal systems offer a promising method for harvesting solar energy. In this paper, a model for a novel linear Fresnel lens collector with dual-axis tracking capability is presented. The main objective is to determine the performance curve of this technology by means of both experiment and theoretical analysis. A mathematical model including the optical model of the concentrator and the heat transfer model of the receiver pipe was developed. This tool was validated with experimental data collected using a proof of concept prototype installed in Bourne, UK. The performance curve of the collector was derived for temperatures between 40°C and 90°C. The results show that the global efficiency of the collector is limited to less than 20%. The energy losses have been analysed. The optical losses in the lens system accounts for 47% of the total energy dissipated. These are due to absorption, reflection and diffraction in the Fresnel lenses. Furthermore manufacturing error in the lens fabrication has to be considered. One third of the solar radiation collected is lost due to the low solar absorptance of the receiver pipe. Thermal radiation and convection accounts for 6% of the total as relatively low temperatures (up to 90 °C) are involved. In order to increase the performance of the system, it is recommended to install an evacuated receiver and to insulate the recirculation system. Considering data from manufacturers, these improvements could increase the global efficiency up to 55%. Utilising the results from this work, there is the intention of building an improved version of this prototype and to conduct further tests.

Advancements in Fresnel Lens Technology across Diverse Solar Energy Applications: A Comprehensive Review

“…A model for a new linear Fresnel lens collector with dual-axis tracking capabilities was provided by Perini et al (2017) [44]. The primary goal was to analyze this technology experimentally and theoretically to identify its performance curve.…”

Optical and thermal performance of a uniaxial bidirectional tracked linear‐focusing Fresnel lens solar concentrator

“…The Fresnel lenses were hosted by an aluminum structure and were maintained normal to sunlight through a 2D tracking device. 10 Experimental results demonstrated that the linearfocusing Fresnel lens with dual-axis tracking could harvest solar energy for all daytime hours. However, such a system takes up considerable land resources and requires large amounts of additional energy consumption to achieve the dual-axis tracking.…”

“…The entire system was mounted on a circular orbit for solar azimuth angle tracking. The Fresnel lenses were hosted by an aluminum structure and were maintained normal to sunlight through a 2D tracking device 10 . Experimental results demonstrated that the linear‐focusing Fresnel lens with dual‐axis tracking could harvest solar energy for all daytime hours.…”

Effect of the collector geometry in the concentrating photovoltaic thermal solar cell performance

“…However, other parameters are determinant in the main features of the solar panels, such as: the orientation (tilt), latitude, azimuth, annual irradiance distribution and commercial applications. A more complete physical model making use of an open-source advanced object-oriented Monte Carlo ray tracing program, such as SolTrace [11] or Tonatiuh [12,13], is required for 3-D calculations, to obtain the light distribution along the receiver. The respective results are also shown and discussed along with a comparative analysis between the proposed collectors and the current solar modules of Solarus AB.…”