Thermo-hydraulic and exergetic performance of a cost-effective solar air heater: CFD and experimental study. (January 2022)

• Record Type: Journal Article
• Authors: Nidhul, Kottayat; Yadav, Ajay Kumar; Anish, S.; Arunachala, U.C.
• Is Part Of: Renewable energy. Volume 184(2022)
• Page Start: 627
• Page End: 641
• Publication Date: 2022-01
• Subjects: Solar air heater -- CFD -- Discrete multiple inclined baffles -- Thermo-hydraulic performance -- Collector efficiency; Renewable energy sources -- Periodicals; Power resources -- Periodicals; Énergies renouvelables -- Périodiques; Ressources énergétiques -- Périodiques; 333.794
• DOI: 10.1016/j.renene.2021.11.111
• Languages: English
• ISSNs: 0960-1481

Abstract

Abstract: An experimental and computational fluid dynamics (CFD) study is carried out to investigate the impact of secondary flow strengthening the thermo-hydraulic performance of discrete multiple inclined baffles in a flat plate solar air heater (SAH) with semi-cylindrical sidewalls. Initially, for a fixed relative baffle height ( R h = 0.1), the relative baffle pitch ( R p ) for continuous baffles is varied in the range of 0.6–1 to obtain the optimum baffle pitch for 6000 < Re < 14000. The impact of gaps at leading, trailing, and both leading and trailing apices are studied as three different configurations with the optimum R p . A maximum thermo-hydraulic performance of 2.69 is obtained for the gap at the trailing apex. The proposed design has a higher collector efficiency, 55–70%, compared to the ribbed rectangular SAH design exhibiting 30–55%. With lower exergy losses, the present SAH design has higher exergetic efficiency (1.5%–2.2%)than ribbed rectangular SAH (0.9%–1.7%) for the range of Re studied. Further, at low Re, the present SAH design has a higher coefficient of performance, indicating that it is cost-effective than ribbed rectangular SAH designs. Abstract : Experimental and computational study of the cost-effective solar air heater. The impact of secondary flow strength on energy and exergetic efficiency is studied. A maximum overall performance of 2.69 is obtained with gap at the trailing apex. The present design exhibits higher collector and exergetic efficiency.