Design And Analysis Of Concentrated Photovoltaic Combined Thermal Power Generation System Based On Cavity Structure

Nowadays,the world is faced with the shortage of energy and the serious problem of environmental pollution,which makes the development and utilization of renewable energy more and more concerned.Among them,solar energy utilization technology is more important and widely used.In order to solve the problem of low efficiency caused by the rising temperature of photovoltaic cells in the current situation of photovoltaic power generation technology becoming more and more mature,this paper designs a cavity array structure focused photovoltaic thermoelectric combined power generation device,which can be used to solve the problem of low efficiency caused by the rising temperature of photovoltaic cells in the process of photovoltaic power generation.Under the condition of ensuring the normal power supply of photovoltaic cells,the heat of photovoltaic cells is well utilized to for thermoelectric power generation,which solves the problem of waste heat of photovoltaic cells and is of great significance to the development of solar energy utilization technology.In this paper,a cavity structure design is proposed in the arrangement of photovoltaic cell and thermoelectric generator,which is mainly composed of three parts: concentrator,photovoltaic cell and thermoelectric generator.Firstly,the operational principles of the concentrator,photovoltaic cell and thermoelectric generator are introduced,and the structure of the cavity and the design of each part of the device are described in detail.The parabolic concentrator is used in the design,and the heat dissipation of the thermoelectric generator is air-cooled.The photovolataic cell,the thermoelectric generator,the heat sink and the collector are placed at the exit of the parabolic concentrator to ensure that the photovoltaic cell and the thermoelectric generator can absorb more solar radiation.A portion of the solar energy that falls on photovoltaic cells is used to generate photovoltaic power,and most of the rest of the light energy is converted into heat to be transferred to the thermoelectric plate.Therefore,photovoltaic cells also use the heat source of thermoelectric generator to help the thermoelectric conversion of the thermoelectric plates and form a combined power generation system.At the same time,the thermoelectric coupling analysis of the components in the device is also carried out,and the heat conduction,thermoelectric generator and heat sink in the heat conduction and heat convection modes are simulated and analyzed respectively.The temperature distribution of three parts at different positions and the output voltage distribution of the cavity structure thermoelectric generator at different temperature difference are obtained.In addition,in order to further improve the performance of power generation,the maximum power point tracking is applied,and the control circuit of the combined generator is designed,in which the Cuk circuit is used in the MPPT control circuit of photovoltaic cells.The Boost circuit is used in the MPPT control circuit of the thermoelectric generator.After the design of the basic device is completed,the part of data acquisition is also described.The collection part mainly introduces the solar energy radiation intensity sensor,the temperature sensor at both ends of the environment and temperature difference,and the selection and design of the collecting circuit of voltage and current.The data collected by single chip microcomputer is transmitted to the software interface of mobile phone through bluetooth module,and the measurement and monitoring of data is realized.Finally,a test platform is set up and the performance of the combined generator is measured and studied.The results show that during the whole-day performance measurement period of the joint generator,the maximum efficiency of joint generation is 20.04%,and the maximum power of generation is 12.2W.The performance of focused photovoltaic thermoelectric system based on cavity structure is better than that of most combined generation systems.The performance of the combined power generating device is better than that of the photovoltaic cell or thermoelectric generator alone.The combined generator not only realizes the cascade utilization of energy,but also improves the utilization rate of solar energy.