Numerical study on thermoelectric-hydraulic performance of a thermoelectric power generator with a plate-fin heat exchanger with longitudinal vortex generators

In this paper, the effect of longitudinal vortex generators (LVGs) on the performance of a thermoelectric power generator (TEG) with a plate-fin heat exchanger is investigated. A fluid-thermal-electric multi-physics coupled model for the TEG is established on the COMSOL® platform, in which the Seebeck, Peltier, Thomson, and Joule heating effects are taken into account. The equivalent thermal-electrical properties of the thermoelectric (TE) module are used in the numerical simulation. The results indicate that the LVGs produce complex three-dimensional vortices in the cross section downstream from the LVGs, thus enhancing the heat transfer and electric performance compared to a TEG without LVGs. Under baseline operating conditions, the heat input and open circuit voltage of the TEG with LVGs are increased by 41-75% compared to a TEG with smooth channel. The simulations also show that the Reynolds number and hot-side inlet temperature have significant effects on the net power and thermal efficiency of the TEG, but the cold-side temperature has a smaller effect. Additionally, the performance of the TEG under a constant heat transfer coefficient boundary condition is almost the same as the performance under a constant temperature boundary condition. Overall, this work demonstrates that LVGs have great potential to enhance the performance of TEGs for waste heat recovery from vehicle exhaust.