Optimization of thermoelectric generator (TEG) integrated with three-way catalytic converter (TWC) for harvesting engine's exhaust waste heat

The exhaust-based thermoelectric generator (TEG) is a promising way to recover the waste heat of internal combustion engines (ICEs). Integrating TEG with three-way catalytic converter (TWC) can improve the output power of TEG and reduce additional pressure drop in the exhaust system. In the present study, some optimization designs for the integration structure of TEG and TWC are carried out through a complete 3-D numerical model. Moreover, the overall performance improvement between the present TEG and a single TEG is illustrated. The results show that the uniform temperature distribution and high output power can be obtained with TWC placed in the rear of heat exchanger. Increasing the number of thermoelectric modules (TEMs) can't always increase the maximum output power of TEG, but can reduce the conversion efficiency of TWC because more heat is absorbed from the exhaust gas. On the condition of maintaining high conversion efficiency of TWC, a moderate height of hollow center body contributes to higher maximum output power of TEG with reasonable pressure drop. Compared with a single TEG, the maximum output power of present TEG is increased by 16%, and the maximum net output power is increased by 37% with considering the power loss caused by the additional pressure drop and increased weight.