Experimental study on the influence of Peltier effect and heat transfer boundary condition on the performance of thermoelectric generator

Abstract

ABSTRACT Thermoelectric generator (TEG) has great potential in waste heat recovery which can convert heat into electricity based on the Seebeck effect, while the Peltier effect is negative and inevitable during the energy conversion process. The heat transfer boundary condition and Peltier effect influence the temperature difference which is the main factor determining the power generation performance of TEG. In this paper, to figure out how the heat transfer boundary condition and Peltier effect influenced the power generation performance of TEG, an experiment system was established. In the experiment, the initial hot side temperature of TEG was controlled by a heater, the cold side was cooled by water which belongs to the convective heat transfer boundary. The temperature variation of the hot and cold side of TEG caused by the Peltier effect under different initial hot side temperatures was analyzed firstly. Then, the temperature, internal heat flow, and power generation performance of TEG under different cooling conditions were investigated. The results showed that the Peltier effect reduced the actual temperature difference and resulted in the difference between the experimental and theoretical power generation performance. In addition, the enhancement of cold side heat transfer boundary conditions could raise the actual temperature difference and thus enhance TEG’s power generation performance. Besides, when the Peltier effect and heat transfer boundary conditions were both considered, the enhancement of the cold side heat transfer boundary condition can reduce temperature loss and thus the relative power generation performance loss caused by the Peltier effect. When the load resistance is 0.1 and the water flow rate increases from 0.1 to 7 , the relative power loss decreases from 29.01% to 20.20%, and the relative efficiency loss decreases from 20.49% to 13.60%. The findings of this work may provide a reference for the study of the heat transfer process of TEG.