Enhancement of the Power-Conversion Efficiency for Thermoelectric Generators

Constrained by low thermodynamic efficiencies, thermoelectric generators (TEGs) require a comparatively large amount of heat to produce a given quantity of electricity. Therefore, further improvements in thermoelectric designs are needed. In this paper, a coupled-field thermoelectric model, which presents a rigorous interfacial energy balance by capturing Joule heating, Seebeck, Peltier and Thomson effects, is developed to gauge the feasibility of the two promising solutions to enhance power generated by the TEGs, utilizing the commercial FEA package COMSOL™ through the Physics Interface Builder. First, the patterned topography on wall surfaces is implemented and the improved performance has been observed by introducing stirred flows into the heat exchangers and equalizing the temperature across the channels. Referring to the analysis, approximately 10% enhancement in power generation can be addressed for the base-relief TEG. Second, the prospect of increasing the thermal transport capability of water by loading CuO nanoparticles in the TEGs with multi-scale heat exchangers is explored. It is found that the conversion performance of the water/CuO nanofluid-based TEG is superior when compared to the water-based TEG at the micro-scale, where the flow rate is relatively low. The significant insight is gained to fabricate the ideal TEGs with optimum power performance.