Renewable Energy, Vol.170, 574-586, 2021
Design and evaluation of flat plate solar collector equipped with nanofluid, rotary tube, and magnetic field inducer in a cold region
Flat plate solar collectors lose a massive part of heat accumulated near the contact region because of the poor thermal characteristics of the working fluid. A new cost-effective design is numerically studied to cover up such deficiency by equipping the flat plate collector with revolutionary tubes and magnetic field inducer to affect Fe3O4/water working nanofluid in the collector tubes. Results substantiate that each of the applied rotary tubes and magnetic field inducer improves the convection mechanism in the tubes by circulating the flow inside the tubes and saves more of available solar energy. Results reveal that 27.8% and 10.44% of lost energy are restored in the solar collector equipped with the magnetic inducer and rotary tubes, respectively. Manipulating the flat plate collector by both rotary tubes and inducer is more influential in comparison with each individual method, and there is an optimal rotational speed in each magnetic field intensity to achieve the best performance. This hybrid technique increases the energetic performance of the plate solar collector from 44.4% to 61.7% which implies that roughly 300 W of the lost energy can be restored in the collector. (c) 2021 Elsevier Ltd. All rights reserved.
Keywords:Flat plate solar collector;Energy and exergy;Thermodynamics;Heat transfer;Magnetic nanofluid