Numerical investigation of an exhaust thermoelectric generator with a perforated plate

Abstract

The thermoelectric conversion efficiency of an exhaust thermoelectric generator is relatively limited and can be increased by optimizing the structure of the exhaust heat exchanger to improve the heat transfer performance. In this study, a mathematical model, based on a fluid-thermal-electric multi-physical field, of an exhaust thermoelectric generator with four rows of thermoelectric modules is constructed to investigate the effect of inserting a perforated plate on the performance of the generator. The insertion of the perforated plate increases the output power of the generator, and an optimal installation position exists that increases the output power by 73.4%. In addition, as the perforated plate is gradually repositioned toward the outlet of the exhaust heat exchanger, the voltage evenness coefficient of the module increases to a maximum of 0.967 and then decreases, with the voltage distribution being the most uniform when the perforated plate is in the middle of the third row of modules. The variation in the mass flow rate and temperature does not affect the optimal installation location, which indicates that the generator has the flexibility to overcome exhaust gas fluctuations. The findings provide guidelines for the structural optimization of thermoelectric generators.