Analysis Of Temperature Field Of Pv Modules And Operation Performance Of A Photovoltaic Sysytem Using Assisited Cooling By Ground Heat Exchangers

The solar cell temperature is a crucial influencing factor to affect the performance of solar photovoltaic module.The photoelectric performance can be improved obviously by taking effective cooling strategy.In this paper,taking the polysilicon solar photovoltaic modules as an example,the operating performance and temperature field were analyzed to evaluate the impact of environmental factors on the temperature field distribution.Based on the results,the performance of the solar photovoltaic modules using assisted cooling by ground heat exchangers(PV/T-GHEs)proposed in this paper was simulated by adopting software TRNSYS.Compared with the PV system,the photoelectric performance of PV/T-GHEs system were estimated in typical regions.The main conclusions are summarized as follows:The photoelectric performance and the temperature field of a polysilicon photovoltaic module were tested.The results showed that the maximum power and fill factor were 187.2W and 71.0%,respectively.In addition,the operating temperatures of operating module were 26.1?56.2? and 22.6?36.0? in sunny and cloudy days.The module temperature of a reference module increased by 3?7? than that of the operating module under the same test conditions.The temperature regression models field of modules under the influences of solar radiation intensity,ambient temperature and wind speed were analyzed,which indicated that the linear regression model was more appropriate for predicting the temperature field distribution of solar photovoltaic modules.The influence of related parameters on PV/T-GHEs system performance was analyzed using software TRNSYS.The results showed that the system performance was affected by the mass flow rate of water,borehole spacing and the thermophysical properties of soil underground.The annual electricity yield and photoelectric efficiency of the system presented a decrease trend with the increase of initial soil temperature.Compared with single U-tube GHEs,the double U-tube GHEs presented a better performance.Furthermore,as the borehole spacing of GHEs increased,the performance of the system tended to be steady gradually after 6m.The module temperature of PV/T-GHEs system decreased dramatically,and the annual electricity yield increased by 7.9% than that of PV system.Considering the differences of division of solar energy resources and geographical locations in China,8 typical regions were selected and the performance of PV systems and PV/T-GHEs systems in different regions were investigated.The results indicated that the electricity yield of the PV/T-GHEs systems increased by 4.4?8.1% than that of PV systems.The long-term operating performances of PV/T-GHEs systems in different solar energy regions were investigated.The results showed that the temperature growth rate of the soil was in the range of 0.12?0.69?/a.Finally,the environmental benefit assessment indicated that PV/T-GHEs system could contribute a better performance than PV system in the regions with high solar radiation intensity.