A novel and efficient thermoelectric-generating (TEG) system of energy harvesting from exhaust gases of passenger vehicles

The exhaust gas from an internal combustion engine carries away about 30% of the heat of combustion. The major technical constraint that prevents successful implementation of waste heat recovery is due to its intermittent and time mismatched demand and availability of energy. In the present work, a thermoelectric generator (TEG) prototype with advanced heatpipe heat exchanger has been developed for capturing waste exhaust heat in vehicles. The completed assembly consists of 60 TEG modules with full electric system component. The overall TEG prototype was tested in a hot-air environment. Improvements in the performance of TEG system have been achieved by facilitating higher heat flux in radial direction of exhaust flow. This high heat flux flow is achieved by means of sandwiching heat pipe based heat exchanger between multi-stage TEG modules. The fuel efficiency is improved by 5% optimally under verifying TEG device and heat pipe exchanger system performance at varies operating conditions. The performance parameters pertaining to the heat pipe heat exchanger and TEG modules such as amount of heat recovered, heat lost, flow rate, conversion efficiency and percentage energy saved are evaluated and reported in this paper.