Study On Characteristics Of Solar Cell Heat Transfer In High Radiation Energy Flux Density Based On The Heat Pipe

Because of high cost and low conversion efficiency, traditional photovoltaic system still not gets into commercial market fully. In order to reduce the use of cells quantity, the cheap condensator was used instead of expensive solar cells in the concentrated photovoltaic system; by use condensator also can increase radiation energy density in per unit area, in order to improve the output power of per unit area solar cells. However, the disadvantage of concentrated photovoltaic system is that the temperature of solar cells would rise rapidly, which will lead to descend of photovoltaic system conversion efficiency. Therefore, it is very significant in research heat transfer characteristic of solar cells in high radiation energy density and high-efficiency and eliminates non-uniformity heat dissipation method.The method of theory analysis and numerical calculate is used in researching heat transfer for concentrated photovoltaic system, in this paper, the temperature characteristic was considered in concentrated system, and design the structure of concentrated system, include the choice of high-power condensator, the variety of solar cells, and the design of heat sink and so on. The laws of temperature and heat stress distribute was analyzed in concentrated condition by theory analysis and numerical simulation. According to the temperature distribution, put forward the choice of cooling method must achieve efficient and uniform heat transfer effects.The main cooling modes was researched for concentrated system at home and abroad, compare with other cooling method, the cooling way of heat pipe was chosen because of the advantage of quick start, high heat conduction, well uniform temperature, small thermal resistance, good heat transfer capability and reliability. Through the establishment of mathematical model, using FLUENT software to simulate the flow and heat transfer characteristics for a single heat pipe, quantitatively described the work situation of the internal heat pipe, compared the different fluid-filled volume and different inclination angle of heat pipe running, finally identified that heat pipe has better heat transfer effect in the case of 30°inclination, which can be applied in the condition of the concentrated cell cooling system.Consider to the limitations of traditional heat pipe cooling, three new types of heat pipe were designed, which can be applied to cell cooling preferably. By the means of numerical calculation, we compared the pressure field, velocity field, temperature field, as well as the volume fraction distribution for the different forms of heat pipe. In the design of the first case, it can significant prevent the occurrence of dry limit and carrying limit, to ensure the normal operation of heat pipe. In the design of the second case and third case, the structure of which was compactly, can be arranged more roots at the back of heat sink, to assure a higher cooling effect. The calculation results of new-type heat pipe and ordinary heat pipe was also compared, what shows that the new-type of heat pipe has more advantages than ordinary heat pipe in the prevention of dry limits and carry limit.