Effects of Performance and Normalized parameters on various materials based Multistage Thermoelectric Generator

Multi-staging and variable cross-section significantly improve the performance of thermoelectric generators. Hence, the present theoretical study analyses a multistage variable-shaped thermoelectric generator (MVS TEG) for a combination of dissimilar materials. Effect on voltage, power, conversion efficiency, normalized constraints (voltage, energy, and conversion efficiency), and second law efficiency with a row number, exhaust inlet temperature, and the coolant flow rate have been investigated. Results reveal that the row number is the most critical input parameter, followed by exhaust inlet temperature and coolant flow rate. Also, the work gives optimum values of rows for voltage and power as Nx=19 for MVS TEG-1, MVS TEG-3, and MVS TEG-4 while Nx=18 for MVS TEG-2. The exhaust inlet temperature variation increases the voltage and power output by 54 to 59% and 53 to 58%, respectively. The coolant flow variation has a more significant impact on the conversion efficiency, and the average improvement in the efficiency is about 9.23% in the present study. The second law efficiency decreases with the increase in all the input parameters.