Evaluation and optimization of fuel economy for an SUV installed with automobile exhaust thermoelectric generators

To generate higher power for an automobile exhaust thermoelectric generator (AETEG), it is usually necessary to install more thermoelectric modules (TEMs) and thermoelectric generators (TEGs), which increase power loss and affect the vehicle's fuel economy. To address the issues, an AETEG was constructed, its thermal and electric behaviours with different TEG units were assessed based on a multi-physical field model, and their impacts on the fuel economy improvement of a sport utility vehicle (SUV) were investigated using a GT-SUITE software. Findings reveal that the proposed numerical model is feasible to predict the temperature distribution, voltage, and power characteristics of the AETEG system with a maximum error of 3.48 %. Backpressure and AETEG weight are the main factors causing power loss, and choosing the optimal TEG number is beneficial for the vehicle's fuel-saving. When 5 TEGs using plate-type heat exchangers are applied at a speed of 125 km/h, the AETEG system achieves a maximum output power and a maximum net power of 721.76 W and 137.1 W, and the fuel economy improvement caused by them is 3.33 % and 0.67 %, respectively. The suggested approach offers a fresh viewpoint on AETEG system optimization and assesses fuel efficiency improvement of vehicles with different TEG units.