Design and construction of a solar tracking system for parabolic-trough collector prototype

Abstract

The search for technological alternatives to satisfy diverse global needs has triggered an arduous process of research and technological developments worldwide for the use of renewable resources. For their part, linear parabolic trough collectors have proven to be an alternative for the water heating process and for the production of electric energy. For its part, the research group in energy systems, automation and control (GISEAC) of the Technological Units of Santander, developed a prototype parabolic trough collector with low-cost materials available in the region (Bucaramanga, Colombia). Consequently, in order to improve the performance of the device, this paper presents the sizing, implementation and testing of a single-axis solar trajectory tracking system in a small-scale parabolic trough collector, applying a closed-loop control system. The control system is governed by a system integrated by an ESP32 module and a Raspberry PI3 microcontroller. The axis of the device is coupled to a mechanism composed of a gear and chain transmission system, directly coupled to an electric motor. The positioning of the collector angle is determined by a sensor that directly measures the amount of LUX and identifies by means of the developed algorithm, the location with the highest levels of direct incident solar radiation. In this way, the system can track the solar position throughout the course of the solar day. Finally, it should be noted that the maximum percentage of deviation of the solar tracking system is less than 1%. At the same time, the performance of the implemented solar trajectory tracking system “Automatic solar tracking system” increased by more than 40% with respect to the initial tracking system “Manual solar tracking system”.