INTERNATIONAL SYMPOSIUM ON AUTOMOTIVE SCIENCE AND TECHNOLOGY, Ankara, Turkey, 5 - 06 September 2019, pp.1-10
This study focuses on energy harvesting from vehicle exhaust gas by employing a thermoelectric generator with a novel structure of heat exchanger. The objective is to achieve a more homogeneous temperature distribution along a number of thermoelectric pieces. The presented heat exchanger design contains an intermediate layer of liquid that helps to attain a more homogeneous temperature distribution. The circulation of the liquid layer and the thermal behavior of the system are investigated by a 3-D computational fluid dynamics model. Liquid sodium is used as intermediate layer fluid. 16 simulation tests were done to identify the efficient operation condition of heat exchanger that circulation of intermediate layer of liquid is effective. These tests are including 4 inlet gas temperatures (500, 550, 600 and 650 K) and 5 inlet gas velocities (48, 60, 70, 80 and 90 m/s).
Results show an increase in heat transfer and power generation of TE modules for all simulation cases except one compared to the reference heat exchanger without an intermediate layer of liquid. In the best inlet gas conditions (600 K-80 m/s), the heat transfer rate is increased by 11.71% and the electric power generation is enhanced by 19.95% by using novel heat exchanger design. The only case that electric power generation was decreased belongs to (650 K-48 m/s) inlet gas conditions.