Design and Experimental Test of Cooling System for Increasing Thermoelectric Generator Efficiency Installed on Vehicle Exhaust

Wasted heat of the exhaust gas in vehicles can be a daily great source for thermoelectric generators. By improving ways of transferring heat and increasing temperature difference between hot and cold side, produced electric power by thermoelectric generators will be increased. Exhaust temperature can be influenced by different criteria such as wind speed and heat sink system. In order to improve transferring heat, change in exhaust geometry and heat exchanger system are investigated in previous works. These changes influence on heat transferring to thermoelectric generators, but can effect on engine efficiency negatively. In this paper heat sink structure and its effect on cold side temperature are investigated. Wind swept on exhaust can be used for cooling system and it is possible by changing heat sink geometry in a good way. By optimization heat sink geometry structure, using energy for cooling by the other systems such as fan or radiator will be decreased. Furthermore, thermoelectric generator accessories will be simpler in comparison to the proposed structures in the previous works which means the proposed design is more economical and practicable. In this study, a 3-D numerical model based on Finite Element Method for calculating various transport phenomena is used. In order to achieve realistic results, a measurement circuit is prepared and temperature on exhaust during driving is registered. The measured values are imported in to the simulations as initial conditions for each step of calculations and temperature distribution in thermoelectric generator and heat sink are calculated. At last, generating power by an assumed thermoelectric generator network on exhaust is discussed. Finally, experimental prototypes of proposed heat sinks are designed and created in laboratory. In this regard, several experimental tests is implemented for validate proposed results of this paper.

Keywords:

Exhaust , Finite Element Method , Heat Sink , Measurement Circuit , Thermoelectric Generators