Exhaust channel optimization of the automobile thermoelectric generator to produce the highest net power

The automobile thermoelectric generator is a promising energy conversion technology to enhance fuel economy and decrease the fuel consumption of vehicles. In order to boost the performance of the automobile thermoelectric generator, the fin distance and thickness of the heat exchanger are fully optimized according to a hydraulic-thermoelectric multiphysics model. The net power model of the automobile thermoelectric generator is established by factoring in weight loss, backpressure loss, and pumping power loss. It is found that the optimization of the fin thickness is primarily aimed at minimizing power loss, particularly backpressure loss, while the key parameter for determining the output performance is the fin distance. Based on optimization results, the optimal fin distance and thickness are 2 mm and 0.5 mm, respectively, resulting in a maximum net power of 45.02 W and a maximum net efficiency of 1.5%. By optimizing the fins of the automobile thermoelectric generator, significant improvements are observed in its performance, with output power, conversion efficiency, net power, and net efficiency increasing by 26.85%, 42.22%, 9.52%, and 22.95%, respectively, compared to the generator without fin optimizations. The results of this study are helpful to guide the design of the internal fins of the heat exchanger.