Mathematical Modelling and Heat Transfer Performance of a TEG for Engine Exhaust Heat Recovery

In recent years, thermoelectric power generation has been investigated widely for waste heat recovery of internal combustion engines. In this paper, the exhaust gas of a heavy-duty diesel engine is used as the heat source. A mathematical model and the simulation program of a large thermoelectric generator(TEG) are established. Using the MATLAB software, the trends of the TEG working parameters in the flow direction are analysed. The flow rate and the temperature of the cold sources, the engine speed and load, and the fin structure parameters of the tube-fin heat exchanger are studied. The results show that the error between the simulated output power and the experimental one is within 11%. A higher engine load rate and a lower coolant temperature are conducive to improving the output power and the conversion efficiency of the TEG. Optimizing the fin spacing and fin height is helpful to improve the heat transfer performance of the heat exchanger and increase the thermoelectric conversion efficiency.