Numerical analysis of heat transfer in a flat-plate solar collector with nanofluids

Heat transfer aspects of a typical flat-plate solar collector utilizing water-based nanofluids as the working fluid were analyzed numerically. Water-based nanofluids of various compositions containing metallic Al2O3 and Cu nanoparticles with volume fractions ranging from 1% to 5% were examined, and the effects of the nanofluids on the heat transfer were quantified. Relevant parameters such as the heat flux, Reynolds number, and the collector tilt angle were calculated and compared to each other at different boundary conditions. The flat-plate solar collector geometry was simplified, and only a fluid carrying pipe with an absorber surface was chosen as a numerical model with a particular at ention to symmetry, instead of taking the entire collector geometry. The numerical model was controlled and confirmed by applying it to similar studies existing in the pertinent literature. All numerical solutions were carried out by using a commercial finite volumes of ware package called ANSYS Fluent. The results show that the nanofluids increase the heat transfer rate ranging from 1% to 8%, when compared to water as a working fluid. © 2017 by Begell House, Inc

Numerical analysis of evacuated tube solar collectors using nanofluids

In this study, numerical analysis of water and water based nanofluids in ETSCs were made by using CFD. Validation of the study was made by comparing an experimental and two different numerical results. Thanks to the analyzes, the effects of water based Al2O3–H2O and CuO–H2O nanofluids compared to water on heat transfer for different volume fractions of nanoparticle, different collector angles, different mass flow rates and different numbers of evacuated tubes were examined. According to these parameters, the thermal and hydraulic statuses of the collector were examined by using the Boussinesq approximation and the tank outlet temperatures were determined. It has been determined that the use of nanofluid in ETSC systems has improved heat transfer and the best improvement was obtained with CuO–H2O nanofluid. © 2019 International Solar Energy Societ