LAUSR

Abstract In order to increase the energy conversion efficiency of thermoelectric generators for automobile systems where the heat sources are commonly cylindrical, a novel concentric annular thermoelectric generator (CATEG) consisting of annular thermocouples and a concentric annular heat exchanger is proposed. A numerical model of the CATEG is first established using a finite-element method, based on which the thermoelectric performances of the proposed CATEG and the conventional annular thermoelectric generator (ATEG) with a cylindrical heat exchanger are compared. The relationship between the size of the heat exchanger, heat transfer characteristics, and heat flow resistances are comprehensively studied. Furthermore, to balance the relationship between heat transmission and fluid flow resistances, and to extract the maximum net power, the optimal design of the concentric annular exchanger is obtained and analyzed. Simulation results show that the optimized ratio of the inner and outer diameters of the heat exchanger is 0.94, and the new ATEG with the proposed concentric annular heat exchanger can significantly increase the total heat transfer coefficient as well as the pressure drop, leading to a maximum net power of 65% higher than the conventional ATEG.