Optimal design of a heat exchanger for automotive thermoelectric generator systems applied to a passenger car

The heat exchanger determines the overall performance of automotive thermoelectric generator (ATEG) systems. To obtain the accurate performance of the ATEG system under actual driving conditions, a fluid-thermal-electric multiphysics numerical model is established. Considering the backpressure loss, weight loss, and pumping power loss, a net power model of the ATEG system is established. The performance of the two heat exchangers with and without fins is investigated and compared. Through optimizations, the optimal parameters for the heat exchanger with fins are NW = 2 rows, H = 30 mm, and NL = 5 columns, and those of the heat exchanger without fins are NW = 2 rows, H = 10 mm, and NL = 4 columns. The output power, net power, conversion efficiency, and net ef-ficiency of the optimal ATEG system with fins are 35.49 W, 22.93 W, 1.89%, and 1.22%, respectively, and those of the optimal ATEG system without fins are 16.49 W, 8.67 W, 1.51%, and 0.79%, respectively. Through the use of fins, the net power and net efficiency of the ATEG system can be increased by 164.48% and 54.43% respectively. The results are helpful to guide the optimization and design of ATEG systems.