Performance Analysis of a Segmented Annular Thermoelectric Generator

We analysed the steady state performance of a segmented annular thermoelectric generator (SATEG). The thermoelectric leg consists of high-, medium- and low-temperature thermoelectric materials joined in series and its cross-sectional area is asumed to be constant. The simplified solution of current in an SATEG and the optimized external resistance corresponding to maximum output power and maximum conversion efficiency are performed. This is more convenient for engineering application than the exact solution. Numerical results calculated based on the simplified solutions agree well with the exact solutions. It is found that the output power and conversion efficiency of an SATEG are not bounded by its segments and can be higher than those of each segment through the proper selection of material combination and segment's length. A design guideline for segmented thermoelectric generators (STEGs) based on figure of merit of high-, medium- and low-temperature thermoelectric segments is proposed. This study will be helpful for the optimization design of STEG devices.