Experimental Study On Thermoelectric Generation Chips Used In The Solar Thermoelectric System

Energy is the material foundation that the mankind relies on existing and the mostimportant drive of the development of human society. With the high-speed progress for thesocial economy and industrialization development, the energy consumption increasing, andthe environmental problems have become increasingly serious. Government has pay attentionto research and use of new energy.As a clean and renewable energy,the solar energy has theadvantages of abundant, widespread, non-pollution, will be further developed and utilized inthe future. How to more effectively utilize the solar energy has become a hot spot scientists.The solar thermoelectric power generation can cover the solar power to electricity powerdirectly.It has the advantages of long life, low-cost and safe operation with immovable parts.It can adjust the system according to details. This page is basing on the thermoelectric powergeneration theory,investigated the heat transfer performance and the electricity generating ofthe system by the means of theoretical analysis, numerical simulation and experimentalresearch. The main research work and conclusions include as follow:(1) The performance parameters were given based on the theoretical derivation and solarthermal energy analysis model. The work performance of thermoelectric generator is analyzedon the base of temperature, contact effect and internal resistance. This relationship provides afoundation for optimizing output power and conversion efficiency.(2) The platform for testing the performance of thermoelectric generator was built. Fourkinds of common commercial thermoelectric modules were studied and the best one wasselected for further study. Profound study was done through experiments on the outputcharacteristics of single thermal power device and effects of different cooling methods on thecold side. When the heat source heat flux is constant, compared with the air naturalconvention, forced air cooling and25℃water cooling and ice-water mixture cooling cansignificantly reduce the cold side thermal resistance and temperature of the cold side. And theoutput power can be increased by30%to80%. This improvement is more obvious while theheating power is larger.(3) The characteristics of a thermoelectric generation system with series-parallelconnection of thermoelectric components are investigated. The results show that, under certain difference of temperature, the open-circuit voltage of two or three pieces of chip seriesare lower than the theoretical value. When the total number of thermoelectric components arefixed, with the increasing of parallel component count, the maximum output power increase,but the output voltage decrease. So we can adjust the number of series-parallel according todifferent requirement, optimize the system.(4) Base on the basic optical principles, combined with the formation principles ofcompound parabolic concentrator(CPC), study of the design method and the main parametersof compound parabolic concentrator, and design a compound parabolic concentrator. Usetrace_pro design software for ray tracing of the compound parabolic concentrator, analysis ofintensity and irradiance distribution of the receiving surface at different angles of incidentlight. Compare the performance of the concentrator at different truncation, it proved that1/3truncation can reduce the use of material and improve the using of the CPC, it is propitious todevelop the CPC.(5) The compound parabolic concentrator(CPC) solar thermoelectric generation systemwas designed base on the characteristics of the chips and the formation principle. The solarcollecting performance and power output performance of the system were experimentalinvestigated. The results showed that the collector has an excellent effect, the maximumcollector temperature can reach92℃. The open-circuit voltage of the system increased withthe temperature difference of the hot side and cold side. When the hot side temperaturereaches80℃, the cold side temperature is about30℃, the heat transfer fluids flow was1200L/h, and the cooling water flow was340L/h, we can obtain the total open-circuit voltageof55.3V and the maximum output power of7.2W with the load resistor of75.6Ω.