Development and heat transfer analysis of a new heat recovery system with thermoelectric generator

In this study, we develop a novel system to recover the waste heat from the exhaust of a passenger car. A heat exchanger is therefore placed after the exhaust manifold of the vehicle. Thermoelectric generators (TEG) are installed on all pipes of the heat exchanger to generate electricity by the temperature difference between hot and cold sides of the TEG. The heat transfer of the TEG is analyzed numerically. Two configurations of TEG units are investigated for various exhaust flow rates and temperatures. The overall heat transfer rates from the exhaust gas to the TEG, the power capacity of the system and the overall heat transfer coefficients of the system are calculated. It is observed that the power capacity of the system is directly related to the inlet temperature and mass flow rate of the exhaust gas entering the system. The power generated by the system can be improved by 90% with an increase of the mass flow rate and temperature of the exhaust gas. Increasing the size of the TEG system by 66.7% rises the overall heat transfer rate of the system by 33.8%.