Numerical analysis in thermal management of high concentrated photovoltaic systems with spray cooling approach: A comprehensive parametric study

Abstract

High concentrator photovoltaic (HCPV) systems receive concentrated solar irradiation and operate at higher temperatures. It is challenging to control the cell temperature in a permittable range preventing overall performance destruction. In the present study, a comprehensive 3D numerical solution is performed to simulate spray cooling on a multijunction HCPV. The effective parameters are categorized as the distance from the nozzle to the surface, the thickness of the thermal paste, and the spray mass flow rate. The results indicate that the spray cooling method reduces the cell temperature below the allowable operating range (353 K). Increasing the distance from the nozzle to the surface raises the maximum cell temperature by 2–14 % in different concentration ratios, causing the cell temperature to exceed the permittable temperature range. Also, the temperature non-uniformity is within an acceptable range between 1.4 and 7.1 K for the minimum distance from the nozzle to the surface. Increasing the thermal paste thickness negatively affects the cell efficiency by increasing the cell temperature and non-uniformity. The cell temperature is reduced by spray mass flow rate, but the net cell output power is also reduced by 1–7 % as the required pumping power increases. At a fixed distance from the nozzle to the surface, the liquid film temperature increases with the concentration ratio, while the thermal efficiency remains almost constant. The best cooling performance was achieved at the minimum distance from the nozzle to the surface (5 mm) and minimum thermal paste thickness (0.5 mm), improving the solar cell's electrical efficiency by increment rate of 0.2 to 1.4 % (corresponding to concentrations of 250 to 1500 suns).