Numerical study on 2-stage phase change heat sink for cooling of photovoltaic panel

Photovoltaic (PV) devices play an increasingly important role in solving the energy crisis. However, the conversion efficiency of the PV panel is small. Cooling of PV panels using phase change devices is an effective way to improve the working performance of PV panels. A phase change device with a two-level arrangement of metal-organic phase change materials (PCMs) is proposed. The PCM is filled in a metal cavity made of aluminium plates. A numerical model of the melting process of the combined PCMs is established, and the flow and heat transfer characteristics of the melting process are analysed. The results show that the temperature variation curve of the metal cavity wall close to the PV panel can be divided into three main stages according to the temperature increasing rate, i.e., the first rapidly rising stage, the slowly rising stage and the second rapidly rising stage. The temperature distribution inside the metallic cavity is more uniform compared to the temperature distribution inside the organic material cavity, and the flow in the metallic cavity is weaker, and the temperature controlling time shows a unimodal variation with the increase of gallium filling proportion in the studied ranges, and the optimal filling proportion is 56.9%.