基于相变材料的环形流动以增强光伏/热能装置的热管理

Abstract A novel hybrid heat sink design has been proposed and analysed for photovoltaic/thermal (PV/T) units, featuring an annular tube with a water flow passage in the annular space and a phase change material (PCM) in the inner tube. Two annular heat sinks are investigated, including the concentric (CAT) and eccentric (EAT) annular tubes. The studied heat sinks are compared under two feeding scenarios: (i) the same head loss and (ii) the same pumping power. The performance of the proposed heat sinks is investigated in the presence or absence of PCM within the inner tube under two solar concentration ratios. A three-dimensional, transient computational fluid dynamics model is developed, and its outputs are post-processed with an energy-exergy analysis. The results reveal that the eccentricity of the inner tube can activate PCM’s capacity for passive cooling of the PV panel, achieving a 4.3–9.08 °C temperature reduction compared to a concentric design, benefiting from its parallel thermal resistance circuit and increased water flow rate in the annulus, without additional initial or operational costs, simply by repositioning the inner tube. Therefore, EAT-PCM achieves higher efficiencies than CAT-PCM: thermal (52.01 % vs. 47.26 %), electrical (14.18 % vs. 13.44 %), and overall (91.39 % vs. 84.58 %), under CR = 2.5.