Thermal performance of a discontinuous finned heatsink profile for PV passive cooling

Abstract

In this work, an improved CFD model based on previous results is used to evaluate the scaling effects on thermal and hydraulic performance of a passive heatsink design for PV panel cooling purposes. PV systems efficiency degrades when operating temperature increases, a common incidence in hot climates exposed to high solar irradiance. In order to reduce the operating temperature of PV modules and maintain their efficiency, a segmented fin heatsink is proposed, whose performance under varying wind attack conditions outperforms the conventional continuous fin profile heatsink design. Numerical simulations using computational fluid dynamics software are presented, assessing different levels of heatsink fin segmentation (fin width) and its effect on hydraulic performance, as well as temperature level and homogeneity of the PV module. Two prototypes were built for experimental evaluation: the model with better results in the numerical tests, and a conventional design homologue, both manufactured following a cost-effective ratio and using 22-gauge aluminum sheet. Numerical simulation showed a temperature reduction of up to 7 °C using the proposed heatsink, as well as a lower temperature gradient. Regarding hydraulic performance, the segmented fin profile reduces pressure losses up to 49% when compared to a conventional heatsink. Experimental results are in good agreement, as thermal images showed a mean temperature reduction of around 5 °C and similar homogeneity. The proposed heatsink design shows improved hydraulic characteristics, thus enhancing heat transfer using the same amount of material as a conventional design.