Renewable energy of waste heat recovery system for automobiles

A system to recover waste heat comprised of eight thermoelectric generators (TEGs) to convert heat from the exhaust pipe of an automobile to electrical energy has been constructed. Simulations and experiments for the thermoelectric module in this system are undertaken to assess the feasibility of these applications. In order to estimate the temperature difference between thermoelectric elements, a network of thermal resistors is constructed. The results assist in predicting power output of TEG module more precisely. Three configurations of heat sinks, which are comprised of 10, 22, and 44 fins, are applied in this simulation. The results of the simulations show the average thermal resistance of these heat sinks in each section of the system with varied velocity of external flow. As the performance of a TEG module is influenced by an applied pressure through the effect of the thermal contact resistance, we clamp the TE module to our experimental apparatus; the relation between power output and pressure applied in this case is presented. Besides simulations, the system is designed and assembled. Measurements followed the connection of the system to the middle of an exhaust pipe. Through these simulations and experiments, the power generated with a commercial TEG is presented. The results establish the fundamental development of materials that enhance the TEG efficiency for vehicles. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3289832]