Investigations of performance improvements on the evacuated tube solar collector with and without the incorporation of preheater through various engineering approaches

Solar irradiation is a clean form of energy, and absorption cooling systems powered by solar energy allow for significant energy savings. In the future, the demand for renewable energy may be the most effective way to serve clean energy, especially in Iraq, which has an excellent geographical location. In this research work, the performances of solar collector with and without of preheater have been evaluated. When compared to flat plate collectors at temperatures above 80°C, glass evacuated tube solar collectors provide the combined effects of a highly selective surface coating and vacuum insulation of the absorber element, resulting in a high heat extraction efficiency. Firstly, the Evacuated Vacuum Tube Solar Collector (EVTSC) was tested through experimentation. Secondly, Computational Fluid Dynamics (CFD) approach has been involved in this EVTSC system and thereby the conductive, convective and radiation based heat transfers are computed. Additionally, all possible with inclusive preheater cases are computationally investigated, thereafter the comprehensive report is prepared though validated computational procedures. Finally, the maximum efficiency is observed to be 53% without using a preheater and 61.8% with the usage of the preheater. The increase in efficiency using the preheater is found to be 16.6%.