Thermal Performance Of Flat-plate Solar Collector Research Articles

Enhancing energy harvesting performance of a flat plate solar collector through integrated carbon-based and metal-based nanofluids

Flat Plate Solar Collectors (FPSCs) have been widely employed in the production of renewable energy for a significant period. To enhance their thermal performance, the utilization of nanofluids as heat transfer fluids has emerged as a popular approach. However, many research works were only carried out with conventional metal-based nanofluids. This numerical study investigates the effects of incorporating two carbon nanotubes, namely single-walled carbon nanotube (SWCNT)/water and multi-walled carbon nanotube (MWCNT)/water, on the fluidic and thermal performance of FPSC. The Nusselt (Nu) and Stanton (St) numbers, as well as the frictional characteristics, are measured and compared to those of metal-based nanofluid of alumina (Al2O3)/water at volume concentrations up to 1%. It is found that Nu increases with a higher Reynolds number (Re) while deteriorating at a higher volume concentration. The lowest Nu was recorded for SWCNT/water in the current investigation. The Stanton number increases with a higher volume concentration and decreases with an increase of Re. Notably, the maximum value of 0.001801 is obtained for the SWCNT nanofluid. The outlet temperature decreases maximum for SWCNT/water with the increase of Re and volume concentration while the friction factor decreases with increasing Re and is independent of the type of nanofluids. Maximum thermo-hydraulic performance parameter of 1.48, 1.32 and 1.29 is achieved for SWCNT, Al2O3 and MWCNT, respectively.

Investigation of the stability of MgO nanofluid and its effect on the thermal performance of flat plate solar collector

Nanofluids are getting the utmost preference for heat transfer applications due to their excellent thermal properties over the base fluid. In the present study, the stability of Magnesium oxide/Ethylene Glycol-Distilled water nanofluid and its effect on the thermal performance of flat plate solar collector (FPSC) was experimentally investigated. Cetyltrimethyl ammonium bromide (CTAB) surfactant was added to the mixture and sonicated to stabilize the suspension. The stability was analysed at different nanoparticle concentrations (0.08%–0.4%) as a function of time. The thermal performance of FPSC was investigated at different particle concentrations (0.08%–0.2%) under varying flow rate (0.5–2.5 Lit/min). Nanofluid characterizations; zeta potential & U–V spectroscopy reveal that nanofluids were stable for more than 15 days up to 0.2 vol% concentration. At higher volume fraction (0.4 vol%), as a result of agglomeration, nanofluid become unstable. The highest thermal efficiency of the collector was achieved by 69.1% for 0.2 vol% at 1.5 Lit/min, which was 16.7% more than EG/DW solely. The results depict that the absorbed energy factor increased by 16.74% and heat loss parameter decreased by 52.2% at the identical parametric condition. The results encourage the use of MgO nanofluid in FPSC.