Performance evaluation of thermoelectric generator using CFD

Abstract

The aim of this study is to analyze various ways to increase the performance of Thermoelectric (TEG) by using Computational Fluid Dynamics (CFD) techniques. For this study a three-dimensional model of TEG is developed using design modeling software SOLIDWORKS and the developed geometry is exported to CFD package which is ANSYS-FLUENT for further analysis. Mass flow rate of exhaust gas is 0.279 kg/s at a temperature of 800 K and mass flow rate of the coolant is 0.26Kg/s at a temperature 350 K are taken as boundary conditions. For this analysis various parameters are investigated such as heat exchanger material, inclination and exit gap of heat deflector and use of baffles. The effect of heat exchanger material on the performance of TEG is investigated. For this investigation pure copper, pure aluminum, aluminum alloy and low-carbon steel are chosen as heat exchanger material. Results show that pure copper has given better performance than others with 184.98 K of temperature difference. To study the effect of exit gap between heat deflector and exhaust pipe on TEG performance, exit gap is varied from 10 mm to 15 mm with an increment of 2.5 mm. The inclination angle of heat deflector is varied from 1° to 3.5° with an increment of 0.5°. Results show that 2°inclination angle of deflector with 10 mm exit gap has given better performance than other inclinations and exit gaps. The influence of baffles on TEG performance is also studied. Introducing a baffle in inclined position directs the flow direction of exhaust gas effectively to achieve better heat distribution. Finally, it can be concluded TEG has good performance with copper material as heat exchanger material, 2° inclination angle of deflector and 10 mm exit gap between heat deflector to the exhaust pipe.