Thermoelectric Performance Of An Exhaust Waste Heat Recovery System Based On Intermediate Fluid Under Different Cooling Methods

Thermoelectric generators (TEGs) can effectively recover waste heat from the exhaust of automobiles and generate electricity. An intermediate-fluid TEG system is based on the vaporization and condensation of an intermediate medium, exhibiting high-efficiency thermoelectric conversion. In this study, a mathematical model of an intermediate-fluid TEG system is established, and the influences of cooling methods and condensed-boiling heat transfer performance in the cavity on the thermoelectric performance are analyzed. The results show that the new generator exhibits better characteristics than the traditional TEG system under both water-cooling and air-cooling methods. We not only improved the power output, but also reduced the optimal thermoelectric module area under the water-cooling method. Moreover, the condensation heat transfer coefficient in the cavity had a significant effect on the power performance of the proposed system. The boiling and condensation heat transfer coefficients should both remain greater than 5000 W/m(2)K for a high efficiency of the TEG. This work provides guidance for the design of new TEGs and high-efficiency utilization of exhaust.