Economic configuration optimization of onboard annual thermoelectric generators under multiple operating conditions

Abstract

Highly variable automobile operating conditions and the ever-fluctuating exhaust parameters pose fundamental challenges to optimizing the design of automobile annular thermoelectric generators (ATEGs). This paper establishes an advanced non-isothermal mathematical model of ATEGs using the finite element method for solving this problem. First, the effects of different vehicle operating conditions on the optimal thermoelectric semiconductor volume are investigated. Based on the results, the optimal range for selecting the thermocouple volume is determined. Aiming to maintain a high net power of ATEG under variable operating conditions, two new schemes are proposed to optimize the system configuration, including 1) a weighted power deviation method and 2) a multi-objective intelligent optimization algorithm. Then, a new method for assessing the power generation cost is proposed for the ATEG. Combined with the characteristics of vehicle exhaust fluctuation in the New European Driving Cycle, the economics of the above two schemes are calculated and compared, and the optimal design is obtained. The results show that the optimal ATEG system configuration is: the PN couple volume in a single ring is 5.0625 × 10−6 m3, the total PN couple volume is 2.835 × 10−4 m3, and the net power and the efficiency can reach 20.85 W and 3.9%, respectively. The proposed model and method contribute to optimize the structural configuration of the on-board ATEGs, and can be further extended for other application scenarios of the thermoelectric generator system.