Investigation into the use of phase change materials in thermal management of a solar panel in the vicinity of tubes with slotted rectangular fins

In this paper, a thermal solar panel is simulated numerically. An enclosure of CaCl2.6H2O phase change material (PCM) is placed at the bottom of the panel in the presence of graphene nanoparticles. A tube is placed in the middle of the enclosure in which alumina-water nanofluid flows at the Reynolds numbers of 200 to 800. A number of fins are installed on the tube. The effect of using three different types of fins in a period of 0 to 5 h and Reynolds number on the panel temperature, PCM volume percentage, output nanofluid temperature, bottom panel thermal resistance, and panel temperature uniformity is examined. The finite element method is employed to solve governing equations. The results demonstrate that the best temperature uniformity on the solar panel occurs at Reynolds number of 800. The Reynolds number of 800 also has the lowest maximum temperature, average panel temperature, and thermal resistance. Using the Reynolds number of 800 instead of 200 reduces the PCM volume percentage from 93.14% to 23.40% and reduces the nanofluid output temperature by 4.3 C. Using fins case 3 creates the minimum temperature on the panel and minimum amount of thermal resistance. The fins case 3 and case 2 produce the minimum and maximum amounts of molten PCM.