EXPERIMENTAL DETERMINATION OF THE EFFECT OF FINS OF DIFFERENT CYLINDRICAL GEOMETRIES ON ELECTRICAL AND THERMAL EFFICIENCY IN AN AIR-COOLED PVT SYSTEM

When the temperature of the photovoltaic cell operating under high radiation intensities increases, there is a decrease in its efficiency, in other words, when it is cooled with a liquid or gas, there is an increase in its electrical efficiency. The thermal energy added to this fluid can be used for different needs. In order to prevent this temperature rise, an experimental setup has been designed and manufactured. For the recycling of solar radiation as thermal energy, cylindrical aluminum fins with different surface areas and different geometries subjected to forced convection have been arranged in the channel. The effects of these fins on the total efficiency were evaluated by making different array configurations within the designed control volume. As a result of the evaluations, it has been observed that a better performance has been achieved in the staggered arrangement, although the surface area is less. In the experimental system, fins with different geometries (3-mm, 6-mm axial channel and helically shaped fins) and array positions (in -line array and staggered array) have been used. With these fins, electrical efficiency depends on the Reynolds numbers (5400, 6400, and 7400) entering the control volume and the radiation intensity (700 W/m2, 950 W/m2, and 1200 W/ m2) is about 13.8-9.7%. This value decreases to 7.9-6.9% in the ordinary PV systems. Thus, it has been concluded that these fins with different surface areas absorb the heat from the photovoltaic cells and play a major role in increasing the efficiency with the decrease in the temperature of the photovoltaic panel. As a result of the measurements, the electrical efficiency of the photovoltaic cells was prevented from falling to 7% under steady-state conditions. In addition to prevention of this energy loss, the thermal energy gained from the control volume is between 630-304 W, depending on the air speed.