Experimental Investigation On Thermal Characteristics Of PV Panel Under Windy Conditions

The thermal characteristics of photovoltaic panel under different conditions are one of the research hotspots in the field of photovoltaic power generation,and the temperature distribution and heat dissipation characteristics of it under different working conditions have been researched by many scholars.The photoelectric conversion efficiency of photovoltaic panel will be affected by its temperature distribution.During the operation of photovoltaic panel,the heat dissipation is an important factor that affects the operating temperature of it.Therefore,the research on its temperature distribution and heat dissipation characteristics plays a crucial role in improving the performance of photovoltaic system.An experimental setup featured by thermal characteristics of photovoltaic panel under windy conditions in the laboratory was established.The impacts of wind velocity V,inclination angleα,wind incident angleβand light intensity G on the temperature distribution and heat dissipation of photovoltaic panel were performed experimentally under windy conditions.The main conclusions of this study are expressed as follows:Under windy conditions in the laboratory,when the distance between the light source and the PV panel is relatively close,and the characteristics of light source is linear,the photovoltaic panel has a local spot phenomenon,and different parameters have different effects on the size,location,and temperature of it.Increasing the wind velocity can reduce the area of the hot spot.There is a critical inclination angle of photovoltaic panel that makes the local spot appears,and the change of inclination angleαwill alter the temperature of the photovoltaic panel and the position of hot spot,while the change of incidence angleβdoes slightly.Increasing the light intensity G will increase the surface temperature of the photovoltaic panel and the area of local spot.Different parameters have different effects on the convection heat dissipation Nusselt number Nu_con photovoltaic panel surface.Increasing wind speed will enhance the convection heat dissipation of photovoltaic panel.The increase of the inclination angle of photovoltaic panel will decrease the convection heat dissipation of photovoltaic panel.The convective heat dissipation Nusselt number of the photovoltaic panel tends to decrease and then rises up with the increase of the wind incidence angle,reaches its peak when the wind incidence angle is 90°.The convective heat dissipation of photovoltaic panel will be enhanced when the light intensity increases.In this paper,uncertainty analysis was carried out on the experimental data and the reliability of this experiment was verified.Finally,the regression analysis was carried out,and a novel empirical correlation for convection heat loss Nusselt number incorporating the factors of inclination angle,wind incidence angle,light intensity and wind velocity was put forward.The analysis results showed that it could be applied in practical engineering.