Study on the performance of TEG with heat transfer enhancement using graphene-water nanofluid for a TEG cooling system

Improvement of the heat transfer effect of cold side of a thermoelectric generator （TEG） is one of the approaches to enhance the performance of the TEG systems. As a new type of heat transfer media, nanofluids can enhance the heat transfer performance of working liquid significantly. In this study, the performance of a commercial TEG with graphene-water （GW） nanofluid as coolants in a minichannel heat exchanger is investigated experimentally at low temperatures. The results show that the output power of TEG increases with the flow rate under 950 mL/min. However, the fluid flow rate has no influence on the output power of TEG with higher flow rate （larger than 950 mL/min） when the heat transfer dynamic balance state of the system is reached. The optimal concentration and flow rate of nanofluid are 0.1 wt% and 950 mL/min, respectively. At the optimal conditions, the improved voltage, output power and conversion efficiency with GW nanofluid applied in the cooling system are increased by 11.29%, 21.55% and 3.5% in comparison with those with only water applied, respectively.