Research On Thermoelectric Performance Of Concentrated Photovoltaic/Thermal Integrated System

Solar energy is one of the most potential energy sources in the world today,which has covered many application fields such as photovoltaic power generation,photothermal power generation,solar heating,industrial and agricultural heat energy utilization,and has a very broad development prospect.The optimal operating temperature range of photovoltaic cells is 25～30℃.Once the operating temperature range is exceeded,the power generation efficiency will be reduced due to the increase of the ambient temperature.At present,monocrystalline silicon and gallium arsenide solar cells on the market have high efficiency,but high cost limits their large-scale use.Therefore,polysilicon solar cells with low cost and improved power generation efficiency are widely used.In order to reduce the working temperature of photovoltaic power generation system and improve the efficiency of polycrystalline silicon solar cells,this paper designs the concentrated photovoltaic/thermal integrated system and explores the research on how to improve the comprehensive utilization efficiency of the system under the integrated photovoltaic power generation and photothermal heat production functions.The main research contents are as follows:Firstly,the theoretical model of the system is constructed.In the Trace Pro software,the concentrating effect of Fresnel lens is simulated,the flow performance of water cooling module is analyzed,and the temperature distribution of the cell after concentrating and the irradiation distribution of the contact surface between the battery and the thermoelectric module are obtained in ANSYS Icepak.On this basis,the photoelectric conversion process and heat transfer process of the solar cell are analyzed.Lay a theoretical foundation for the follow-up study.Secondly,the feasibility of establishing photovoltaic power station is analyzed in PVsyst photovoltaic simulation software.Through collecting the annual meteorological data,such as temperature and solar irradiance,this paper discusses the optimal Angle of daylighting surface in Harbin,analyzes the output power of photovoltaic cells under different conditions and each output simulation,and obtains the ratio of power generation and performance of the system through calculation,and draws the conclusion that it is suitable for building a concentrating photovoltaic/thermal power station in Harbin.Finally,a test platform was built to analyze and record the effects of different temperatures and solar irradiance on the efficiency of the system.The test results show that the maximum output power of concentrated photovoltaic/thermal integrated system can reach 2.67 W,the average power generation efficiency is 24.1%,the heat utilization efficiency is 48.3%,and the total energy utilization rate is 72.4%.The measured actual power generation efficiency of the photovoltaic system is similar to the calculated value of the theoretical model.At the same time,the variation of the power generation efficiency of the system with the solar irradiance under different cooling water flows is analyzed.The comprehensive analysis of the test results shows that temperature,solar irradiance,cooling water flow and other factors will affect the thermoelectric performance of the system.Therefore,the system should be adjusted flexibly in order to improve the thermoelectric performance.The system studied in this paper can achieve efficient power generation throughout the year,improve the practicability of solar photovoltaic photothermal power generation technology,and provide technical and theoretical support for the industrialization of building photovoltaic/thermal integrated system.It is expected to achieve large-scale mass production in the future.