Influence of foamed metal core flow heat transfer enhancement on the performance of thermoelectric generators with different power generation characteristics

Abstract

• Core flow heat transfer enhancement with foamed metal has been studied by experiment. • The effect of different PPI of the foamed metal has been analyzed. • The effect of different filling rate of the foamed metal has been analyzed. • PEC and OP are used to analyze the performance of enhancing heat transfer at core flow. With the development of science and technology, how to recycle the waste heat of high-temperature exhaust gas discharged from daily life and industry has become the focus of attention of the scientific community. Using thermoelectric generation technology to recover and utilize the waste heat of high-temperature gas of this part can effectively improve the efficiency of energy utilization. The thermoelectric generator (TEG) is modified by inserting the foamed metal copper (FMC) at the core flow field of the heat exchanger tube to enhance the heat transfer, and the heat exchange capacity of the heat exchanger can be effectively improved, so that the power generation efficiency of the TEG can also be effectively improved. At the same time, the core flow filling method can also reduce the increased amplitude of the back pressure of the TEG. Therefore, in this article, experiments have been conducted to investigate the effect of improved heat transfer of FMC at the core flow field on the performance of TEG with different power generation characteristics. We first evaluate the effect of different enhanced heat transfer conditions on the heat transfer capacity of TEG hot end heat exchanger with the Performance Evaluation Comprehensive (PEC) evaluation method. The results showed that the enhanced heat transfer by the FMC at the core flow field can significantly improve the heat transfer capacity of the heat exchanger. Then we use the Overall Performance (OP) evaluation method to evaluate the effect of TEG on its performance under different enhanced heat transfer conditions. The results showed that the power generation of the TEG filled with FMC at the core flow field is higher than that of the unfilled TEG, and the filling of FMC with a high filling rate and high pore density can significantly improve the power output and power generation efficiency of the TEG. However, by evaluating the TEG filled with FMC at the core flow field through the OP evaluation method, it was found that the use of FMC with a low filling rate and low pore density can better improve the overall performance of TEG.