Experimental and numerical study of a linear Fresnel solar collector attached with dual axis tracking system

Abstract

The demand for an alternative to fossil fuel energy is increasing as environmental and economic challenges rise. The linear Fresnel solar collector is considered a promising option for obtaining thermal energy at medium and high temperatures. A linear Fresnel solar collector consists of a number of mirror strips that are used to focus solar beam radiation toward a line receiver. This study aims to obtain a clear evaluation of the thermal performance of a linear Fresnel solar collector through design, manufacture, and experimental testing under different outdoor conditions in Baghdad over various periods. There have been tests on April 1 and 22, as well as May 8 and 27, using water as the working fluid. The solar collector used is an aluminum base measuring 200 cm in length and 150 cm in width on which 14 mirror strips from each side are fixed. The receiver (absorber copper tube) has a length of 200 cm and a height of 60 cm from the base. The solar collector is provided with a dual-axis tracking system (North-South and East-West) for ensuring that the solar concentrator faces the sun at normal incidence during all daytime hours. The best thermal performance of the solar collector was observed on May 27, where the average useful energy, thermal and exergy efficiency reached 1042.61 W, 39.15 %, and 1.31 %, respectively. The present study also included a numerical analysis done using computational fluid dynamics (CFD) to verify the experimental results. The numerical results confirmed the validity of the experimental results.

Keywords

• Linear Fresnel collector
• Thermal efficiency
• Exergy efficiency
• Tracking system
• CFD