Numerical an‎d Experimental Study of a Direct Absorption Solar Collector with Laser-Processed Surfaces an‎d Hybrid Nanofluid

1/14/2027 12:00:00 AM

Given the growing necessity for utilizing renewable energies in the modern era, solar energy, as an unlimited an‎d widely accessible source, represents an ideal option. For harnessing this energy in laboratory an‎d industrial applications, direct absorption an‎d indirect absorption parabolic collectors have been widely employed. In this research, modifications were made to both the absorber tube an‎d the heat transfer fluid in order to enhance the performance of a direct-absorption parabolic solar collector. For surface modification, a pulsed fiber laser processing technique was applied to a copper surface. Through rapid photothermal processes such as surface melting an‎d resolidification, the formation of laser-induced periodic surface structures, an‎d the growth of thin oxide layers, the surface morphology was altered, resulting in quasi-metasurface properties. Consequently, by increasing spectral absorption an‎d reducing reflectivity, the efficiency of the copper surface as a solar absorber was significantly improved. Different surface patterns, including vertical line, circular, an‎d horizontal line patterns, were fabricated on the copper surface an‎d tested inside the absorber tube of the collector. In terms of fluid modification, silicon dioxide, aluminum oxide, titanium dioxide, an‎d multi-walled carbon nanotube nanoparticles were investigated. Ultimately, a hybrid nanofluid comprising the most effective nanoparticles in enhancing the thermo-optical properties of the base fluid was selec‎ted an‎d prepared. The main performance parameters investigated include thermal efficiency, pressure dro‎p, an‎d performance factor. The highest thermal efficiencies for water, laser-processed surfaces, an‎d the hybrid nanofluid were 21.95%, 38.99%, an‎d 49.68%, respectively. Due to the relatively low pressure dro‎p of the nanofluids, the minimum performance factor for them was 1.30, whereas the maximum value of this factor for laser-processed surfaces was obtained as 1.08. Moreover, the combined effect of the optimized laser-processed surface an‎d the hybrid nanofluid was also examined, an‎d the maximum thermal efficiency for this configuration reached 53.12%. In addition to the above metrics, other parameters such as exergy efficiency, environmental pollutant reduction, an‎d the specific cost of energy production were eva‎luated for all cases.

كلكتور خورشيدي , انرژي خورشيدي , نانوسيال , نانوسيال هيبريد , كلكتور سهموي , كلكتور جذب مستقيم , ليزركاري

Solar collector , Solar energy , Nanofluid , Hybrid nanofluid , Parabolic collector , Direct absorption collector , Laser surface processing

Amirhossein Edalatpour

Seyed Mostafa Hosseinalipour