Study On The Preparation And Performance Of Microchannel Heat Sink For Concentration Photovoltaic Solar Cells

Concentration photovoltaic(CPV)is a high efficient and green renewable energy,which can effectively alleviate the increasingly serious energy and environmental crisis.However,concentration photovoltaic can improve the efficiency of power generation through concentrating,and it will cause heat accumulation,and even cause the performance degradation or even damage of concentration photovoltaic cells.Therefore,high-efficiency microchannel heat sink was used to achieve hight heat dissipation of CPV cells.Through the design and preparation of microchannel structure of high-efficiency microchannel heat sink,and integrated packaging with low thermal resistance of photovoltaic cells,and then tests and evaluates the electrical and thermal performance of the high-efficiency microchannel heat sink cooling photovoltaic system,so as to improve the electrical and thermal performance of the photovoltaic system.Firstly,the channel with special inverted ’Ω’ cross-section is designed,and the copper microchannels including parallel channel,serpentine channel and staggered channel,are fabricated by micro milling and then the microchannels heat sink was finshed by welding sealing.By the way of thermal conductive silicone gel,the concentration photovoltaic cell and microchannel heat sink are integrated and packaged.And the integrated design structure with low thermal resistance and manufacturing process of microchannel and concentration photovoltaic cell insulation layer are proposed,and the integrated heat dissipation structure is completed.Secondly,the thermal simulation model of photovoltaic cells and microchannel heat sink module is established,and fluent is used for simulation.It is found that the serpentine channel with special inverted ’Ω’ cross-section can induce turbulence,promote the mixing of cold and hot fluids,and improve the heat transfer performance.It is found that increasing the flow rate can improve the heat dissipation performance,and with the continuous increase of the flow rate,the improvement of the heat dissipation performance slows down.And the maximum temperature difference of the upper surface of the battery chip is within 1℃ under the different structures.Design and build a concentration photovoltaic outdoor experiment system for comparative test,and performance of single photovoltaic cell module based on microchannel heat sink were tested.Compared with fin air cooling,microchannel heat sink can effectively control the average temperature of cell bottom within 30℃,which is 20-30℃ lower than that of fin heat dissipation under the same conditions.In this experiment,the output power of microchannel can be increased by 56%compared with fin.In addition,the influence of the conditions of the secondary concentration,the internal structure of the microchannel,the entrance flux and the concentration ratio was studied systematically.The array amplification system is designed and performance is analyzed for the microchannel module of concentration photovoltaic cell,the experimental is carried out in pure series and pure parallel way.In both ways,microchannel cooling technology can show excellent temperature control ability.In parallel mode,the overall output electrical performance of microchannel under heat dissipation has been greatly improved,up to 16.3%.