Modeling the Effects of Module Size and Material Property on Thermoelectric Generator Power

It is known that thermoelectric power generators (TEGs) can utilize geothermal resources and recycle waste heat. It is vital to improve the thermoelectric power generation efficiency to economically and efficiently use these thermal resources. In this paper, ANSYS was used to build a three-dimensional model of a very simple TEG with only one pair of p- and n-legs (1-PN-TEG) to find the optimal design. The thickness of the semiconductor elements, the cross-sectional area of p- and n-type semiconductor elements, the heat insulation material, the thickness of copper sheet, and other factors were analyzed to study their effects on the power output of 1-PN-TEG. The results show that the power of TEG increases first and then decreases with the thickness of p- and n-legs (H); the maximum power existed at a specific value of H. The power increases when the cross-sectional areas of p- and n-type semiconductor elements become more extensive, but the power per area decreases. Furthermore, the power increases with the volume of p- and n-type semiconductor elements and tends to be stabilized finally. This observation may be used to estimate how much thermoelectric material is required to generate a specific value of TEG power. The gaps between p- and n-type semiconductor elements were filled with different heat insulation materials. The heat insulation material with lower thermal conductivity had a greater power output. The thickness of the copper sheet, as a conductor between p- and n-type semiconductor elements, was also investigated. The maximum power value was reached when the thickness of the copper sheet was equal to about 1.0 mm. All of the results obtained in this paper might provide a theoretical basis for the configuration and design optimization of a thermoelectric generator, making more efficient use of geothermal resources and the waste heat.