Experimental and analytical evaluation of nanofluid based parabolic trough solar collector under varying concentrations, flow rates, and ambient temperatures

Among the various solar energy harnessing techniques, the parabolic trough solar collector has emerged as a widely adopted and proven method, delivering solid performance results for both domestic and industrial applications. In this article, alumina-deionized water nanofluid was synthesized at different concentration such as 0, 0.5, 1.5, 2.5, and 3.5 % by volume and exercised at various mass flow rate of 0.02, 0.03, 0.04, 0.05, and 0.06 kg/s on parabolic trough solar collector from 8.00am to 4.00pm daily and it proved fruitful results as first phase. In connection with the experimental work phase, an analytical study was carried out in this study to assess the impact of ambient temperature increase (5 %) on parabolic trough solar collector (PTSC) without allowing any modification in properties and parameters other than ambient temperature and its related calculated properties. While many researchers have explored physical modifications to enhance parabolic trough solar collector's performance, this article makes a step forward by offering an analytical investigation grounded in experimental results. The findings reveal a modest improvement in key performance parameters, such as collector efficiency and global efficiency, which increased by 0.103 %–0.206 % and 0.09 %–0.240 %, respectively, for alumina-deionized water nanofluid concentration of 3.5 % v/v. On the other hand, a decrement was observed in Reynolds' number, ranging from 1.358 % to 0.935 %, and in Nusselt number, ranging from 0.848 % to 0.545 %, at a 0.5 % nanofluid concentration. The wind loss coefficient decreased, ranging from 0.453 % to 0.076 %, at 3.5 % nanofluid concentration. Based on experimental data, the analytical study provides critical insights into the influence of ambient temperature increase on the performance of parabolic trough solar collectors. The results underscore the potential for performance optimization through the strategic use of nanofluid and ambient temperature management.