Qualitative modeling of solar panel cooling by nanofluid jets: Heat transfer and second law analysis

The present paper highlights heat transfer and entropy generation due to mixed convection for an inclined channel. The channel is heated by its upper wall and cooled by two jets of nanofluids penetrating through its lower wall. The studied configuration is chosen to model, in qualitative way, a cooling system for photovoltaic panel. The set of partial differential equations that governing the flow was numerically solved using COMSOL software. Effects of the inclination angle of the channel, Reynolds number and nanoparticles fraction, on heat transfer, hydrodynamic and created entropy are examined. The inclination angle, the Reynolds number and the nanoparticle fraction are ranging from 0 degrees to 30 degrees, from 50 to 150 and from 0% to 8% respectively. It was found that the effect of the angle of inclination, on heat transfer and thermal irreversibility, is weak and that it cannot exceed 2%. Whereas the nanofluid concentration and the Reynolds numbers alter at once the created entropy and the heat transfer. Results show an increase of nearly 15% of Nusselt number and thermal irreversibility when the nanoparticle concentration reaches 8%. The local irreversibility maps reveal that the created entropy is significantly localized at the impact locations of the cooling jets. Since irreversibility is synonymous with the aging of the system, which naturally leads to usury, it can be concluded that the channel may be damaged at these locations.