Design of thermoelectric modules for both mechanical reliability and performance using FE simulation

Thermo-mechanical modeling of the TE modules provides an efficient tool for assessing the mechanical strength of the modules against the induced thermal stresses and subsequently optimizing them in terms of the mechanical reliability. However, the design of TE modules in terms of mechanical reliability cannot be separated completely from the design for performance. These two objectives may conflict such that the improvement of the design parameters for one objective can deteriorate the other one. This trade off can be seen particularly when the geometrical dimensions of a TE module is optimized for these two objectives.
The current study deals with FE simulation of the TE modules to optimize their geometrical dimension in terms of mechanical reliability and performance. First, FE simulation of a TE module consisting of bismuth telluride alloys is carried out and the induced thermal stresses, output power and efficiency of the module is calculated. Then, the geometrical dimensions of the module including the leg length and the cross sections of the TE elements are varied and the corresponding maximum thermal stresses, output power and efficiency of the modules are obtained. Based on the results, the geometrical dimensions of the TE elements for both mechanical reliability and performance are optimized to obtain a compromise design. The present work provides a basis for optimizing the TE modules in terms of their life time and performance.