A novel heat sink for cooling photovoltaic systems using convex/concave dimples and multiple PCMs

Abstract

• PV system integrated with convex/concave dimples and multiple PCMs is numerically studied. • The dimpled surface enhances the melting rate without changing the PCM mass. • The multiple PCMs improve the thermal and electrical performance of the PV system. • The highest performance occurs at (two-PCMs:15–5 mm) arrangement with 8 dimples. The operating temperature of a solar panel affects its electrical efficiency. As the temperature increases, the solar cell's ability to generate electricity decreases so cooling is required to improve its performance. In this study, a novel design of photovoltaic phase change materials (PV-PCMs) system is established. It consists of a separate convex/concave dimpled aluminum plate and multiple PCMs that act as a heat sink. In order to achieve longer thermal management of PVs, the PCMs were arranged along the heat flow direction according to the melting temperatures. The thermal and electrical performance of the PV-PCMs system was numerically analyzed at different inclination angles. The system was tested using different numbers of dimples (smooth, 6, 8, and 10 dimples) and multiple PCMs with different thicknesses (single PCM, two-PCMs:10–10 mm, two-PCMs:15–5 mm) to obtain the optimal design. The numerical model and the literature data agreed very well. The (two-PCMs:15–5 mm) arrangement with 8 dimples provides the longest uniform operating temperature duration and the highest PV electrical efficiency. The thermal management durations were 40, 30, and 25 min, during which the percentage decrease in PV cell temperature was 7.14, 4.65, and 2.22 % at an inclination angle of 90°, 60°, and 30°, respectively, compared to the smooth wall with a single PCM. The novel design is recommended for future modeling of the PV-PCMs system.