Exploring performance variations of mono-nanofluid-based parabolic trough solar collectors at various concentrations and mass flow rates: an experimental analysis
摘要
In the renewable energy category, solar energy is one which is an abundantly available, inexhaustible nature, and promising type of energy. It is evergreen, non-polluting, and never provides any screen towards its continuous utilization without any cost. One can opt for this energy, for both electrical (photo-voltaic) and thermal (collector) energy production. Considering the above points and to promote the solar energy utilization from domestic level, an analyses was carried out, to investigate the performance enhancement due to application of alumina/de-ionized water nanofluid in parabolic trough solar collector. To carry out the experiment, a small-scale parabolic trough type solar collector was fabricated with an aperture area, absorber area, rim angle, focal distance and minimum image width as 1.05936 m2, 0.06211 m2, 69.34°, 0.3 m and 0.015856 m, respectively. Alumina-de-ionized water nanofluid at various volume fractions from 0 to 4.0%v/v and flow rates of 72–216 kg h−1 was allowed to flow through the copper receiver tube (concentration/flow rate/day). The outcomes of experimental work showed that the heat loss coefficient was in the range of 4.594 @ 1.0% & 108 kg h−1 and 5.389 W m−2 K-1 @ 4.0% & 216 kg h−1, while the heat transfer coefficient lies between 477 and 1943 W m−2 K−1 @ 2.0% concentration. On the daily average, the results showed that the collector, global and thermal efficiencies were 68.43, 67.03 and 33.05%, respectively, and the corresponding enhancement was reported as 14.45, 8.52 and 48.81%. Finally, this experimental analysis and performance model were compared with previous work, which ensured that the present model, lies between Valanarasu’s (< 3.14%) and Murphy’s (> 1.56%) models. The economic feasibility and experimental error were well within the control.
Graphical abstract