Design, Fabrication and Experimental Testing of Solar Parabolic Trough Collectors with Automated Tracking Mechanism

This paper was concerned with an experimental study of parabolic trough collector’s with its sun tracking system designed and manufactured. To facilitate rapid diffusion and widespread use of solar energy, the systems should also be easy to install, operate and maintain. In order to improve the performance of solar concentrator, different geometries and different types of reflectors were evaluated with respect to their optical and energy conversion efficiency. To assure good performance and long technical lifetime of a concentrating system, the solar reflectance of the reflectors must be high and long term stable. Therefore, different types of reflector materials and absorbing materials were analyzed in this work; also the optical properties and degradation of the reflecting surfaces were assessed. During the research, focus has shifted from evaluation of the performance of concentrating solar collector to analysis of the optical properties of reflector and absorbing materials. The shift of focus was motivated by the need to assess long term system performance and possibilities of optimizing the optical efficiency or reducing costs by using new types of reflector materials and absorbing materials. For the design of the SPTC frame, a finite element model had been developed and used to check the capability of the structure to absorb torsion and bending forces, under dead and wind loads. The SPTC was fabricated in local workshops and the sun tracking system was assembled using electric and electronic components in the market, while the mechanical components making up the driving system were procured from the second hand market. The fabricated SPTC and its tracking system were tested outdoors in the campus under dry and wet weather. The experimental results obtained have shown that the obtained characteristic curve of the tested Aluminium collector is considerably lower than that of a mirror collector which can be attributed to the higher thermal losses for the lack of the evacuated glass envelope around the absorbing tube, the end losses of the collector and the inaccuracy in tracking the sun. However, the mirror collector efficiency is about 8% higher than that of Aluminium under dry weather condition, which is fairly acceptable, considering that it was the first attempt to manufacture such mirror collector locally. Thus, the overall aim of the INTERNATIONAL JOURNAL OF RESEARCH IN AERONAUTICAL AND MECHANICAL ENGINEERING Vol.1 Issue.4,August 2013. Pgs: 36-55 Pradeep Kumar K V, Srinath T, Venkatesh Reddy 38work presented in this research was to investigate