Finite Element Simulation of Micro-Thermoelectric Generators Based on Microporous Glass Template

Abstract

COMSOL Multiphysics software-based three-dimensional finite element analysis is widely used in the performance simulation of thermoelectric devices. In this study, this software is used to simulate the heat transfer processes and power generation performance of micro-thermoelectric generators based on a microporous glass template. The temperature and electrical potential fields are coupled to each other through the thermoelectric effects during the calculations. The power generation performances of micro-thermoelectric generators with different template heights (d) for various temperature differences between their hot and cold ends (∆Th-c) are calculated. For the micro-thermoelectric generator that included four pairs of TE couples, the temperature difference between the two sides of the TE columns (∆TTE) and the open circuit voltage (Uoc) both increased with increasing d, but the growth rate gradually decreased. When d is greater than 0.2 mm, the increment basically becomes negligible. The maximum output power (Pmax) first increases and then decreases with increasing d, reaching a maximum value when d is 0.2 mm. Therefore, we can optimize the size of device according to the simulation results to ensure that the device produces the optimal output performance during the experiments. A model with the same parameters used in the experiment (i.e., d=0.2 mm) was then established and it generated a Uoc of 35.2 mV and a Pmax of 228.8 μW when ∆Th-c was 107.5 K (∆TTE = 97.55 K). The errors between the simulation and the experimental results are small and thus also verify the accuracy of the power generation performance test results.