Study of the influence of material properties in the energy conversion process of thermoelectric generators for waste heat recovery applications

The present study analyzed the effect of material properties in the energy conversion process of Thermoelectric Generators (TEGs). For the development of the study, two materials whose properties vary with respect to temperature (Bi0.4Sb1.6Te3 and Cu11NiSb4S13) and a material with constant properties (Bi2Te3) were analyzed. Through numerical simulation processes, each material was subjected to different temperature differences to monitor the effect on the electrical output power, heat flux, and energy conversion efficiency. The results showed that neglecting the temperature dependence produces higher or lower performance estimations depending on the temperature levels experienced by the TEG.  Overall, the material Bi2Te3 displayed 35% more electrical power output and conversion efficiency compared to the Bi0.4Sb1.6Te3 material. Therefore, considering the variability of thermoelectric materials demonstrated to be essential to obtain realistic process performance. Also, the heat flux produced by the Fourier effect presents the most significant impact on the electrical power generation of the TEG. Among materials with variable properties, the Bi0.4Sb1.6Te3 increases the conversion efficiency up to 25% compared to the Cu11NiSb4S13. In conclusion, the study of material properties using numerical simulations emerged as a robust and practical tool to evaluate TEG performance.