Performance investigation of a thermoelectric generator system applied in automobile exhaust waste heat recovery

In this paper, a novel fluid-thermal-electric multiphysics numerical model is presented to predict the performance of a thermoelectric generator system applied in automobile waste heat recovery. The model considers the complete geometry, temperature-dependent material properties, topological connection among thermoelectric modules, and impedance matching, which can simulate the actual working conditions. Numerical simulations are carried out on the COMSOL platform combined with the exhaust temperature and exhaust mass flow rate under different vehicle speeds. In addition, the detailed physical field distribution characteristics of the automobile thermoelectric generator system, as well as the variations of output power, conversion efficiency, power losses, and net power with vehicle speed, are obtained. The position of thermoelectric modules on the hot side heat exchanger plays an important role in output uniformity, and the higher the vehicle speed is, the more uniform the output will be. At the vehicle speed of 120 km h(-1), the output power and conversion efficiency of the automobile thermoelectric generator system are 38.07 W and 1.53% respectively. Considering the weight power loss and coolant pumping power loss, the net power is 23.66 W. This work fills the gap in evaluating the performance of automobile thermoelectric generator systems at different vehicle speeds comprehensively. (C) 2021 Elsevier Ltd. All rights reserved.