Comparative analysis of solar-tracking and static solar collector efficiency

The objective of the present work is to conduct a comparative analysis of fixed and moving flat-plate solar collectors’ operation. A testing programme is performed on an experimental set-up installed on a location in Shtip (R. of Macedonia), latitude 41o 45’ and longitude 22o 12’, in order to investigate the effect of the sun tracking system implementation on the solar collector efficiency. The set-up consists of two liquid flat-plate solar collectors, one with a fixed surface tilted at 30о towards the South, and the other one equipped with dual-axis solar-tracking system. The research includes development of a 3-D mathematical model of the collectors system and an extensive numerical simulation programme, based on the computational fluid dynamics (CFD). The main aim of the mathematical modelling is to provide information on conduction, convection and radiation heat transfer, so as to numerically simulate the heat transfer performances and the energy capture capabilities of the fixed and moving collectors in various operating modes. The feasibility of the proposed method was confirmed by experimental verification, showing significant increase of the moving collector, compared to the immobile collector unit. The comparative analysis demonstrates a good agreement between the experimental and numerically predicted results for different running conditions. This is a proof that the presented and verified CFD modelling approach can be used for further investigations of different configurations and flow schemes of thermal solar collectors