Experimental Study And Optimization Of Solar Thermoelectric Power Generation Device

As a representative of renewable and clean energy, solar energy is one of the mostwidely used energy sources at present. Solar Thermoelectric Power Generation Device(STPGD), with the advantages of non-pollution, non-noise, non-moving parts, highreliability and environment friendly, has become an important and promising way toconvert solar energy into electricity. In this thesis, detailed theoretical analysisand experimental study on STPGD were conducted to obtain the power outputperformances of Thermoelectric Module (TEM) and to optimize the STPGD system.Firstly, a description on the basic principles, such as the Seebeck effect, Peltier effect,Thomson effect, Joule effect and Fourier effect, and the interrelationship of these effects,were presented. Then, the characteristics of solar radiation spectrum, the principle ofselective absorption coating and its application in STPGD system, and the workingprinciple of STPGD system were introduced in detail. Based on the above analysis, amathematical model of STPGD system was established to analyze its internal heat transferprocess, output power and system efficiency. Based on the results, the requirements of theworking conditions, under which the STPGD system having the maximal output power orsystem efficiency, were presented.Secondly, the TEM performance test setup was established, and the relationshipsbetween output power and temperature difference of a single TEM and a4-TEM array werederived. The experiments showed that the4-TEM array’s output power was larger than thesum of the output powers of4single TEMs at the same temperature difference. Then, bydesigning and testing a prototype of the STPGD, it was found that when the ambienttemperature was100C and solar irradiance was715W/m2, the temperature difference of theTEM was about600C. Meanwhile, an experiment about the influence of the spot’suniformity on the performance of the STPGD system was accomplished, and the resultshowed that a more uniform spot can enhance the efficiency of the STPGD system.Finally, based on Diffused Focal Points (DFP) method, a design of Fresnelconcentrator with high irradiance uniformity was done. Then, a numerical simulation based on Monte-Carlo ray-tracing method was conducted, and the results showed that DFPmethod can significantly improve the uniformity of solar irradiance distribution, comparingto the traditional method. Moreover, in the DFP method, two arrangements of the lens werecompared, and it was found that the uniformity is better when the lens is arranged in a crossarrangement. The cross arrangement could enhance the working performance of theconcentrator.