The PCM-porous system used to cool the inclined PV panel

Abstract

The PCM composited with metal foam (PCM-porous system) as heat sink to cool photovoltaic (PV) panel is a potential application. However, there has little attention on the differences in cooling effect of PCM-porous systems when PV panels install with different inclination angles. To fill this research gap, the charging processes of PCM-porous systems with different inclined angles (φ = 0°, 30°, 60°, 90°) have been investigated numerically and experimentally in the current work. Meanwhile, the influences of different Rayleigh numbers (Ra = 1.4568 × 106, 1.8210 × 108, 1.1654 × 1010) have been considered. Results show that the inclined angle has little impact on the PCM-porous system with small porosity (ε = 85%, 90%), which is much different from the PCM-porous system with larger porosity (ε = 95%). In the discussion, an interesting phenomenon has been found that the weak natural convection of liquid PCM in porous media induced by the inclined cavity plays a negative role in melting process, which is obvious in PCM-porous system with small porosity (ε = 85%, 90%). But this negative effect is not necessarily a bad thing due to that it can extend the duration time to cool the PV panel. The maximum duration time of PCM-porous system with ε = 85% or 90% is 2 times of system with ε = 95% (φ≠0°).