A novel strategy of inserting radiation shields to enhance the performance of thermoelectric generator systems for industrial high-temperature heat recovery

Abstract

Static thermoelectric generator (TEG) systems have been widely used for recovering the high-temperature heat from the industrial sector. To control the heat loss through the gap uncovered by the thermoelectric legs for system performance improvement, a novel strategy of inserting the radiation shields in the gap that introduced additional surface and spacing resistances and regulated the gap radiation loss, was proposed. With a constructed high-fidelity theoretical model which used the finite element method to consider the temperature-dependent properties of the thermoelectric materials, comprehensive comparisons were conducted between the systems with/without radiation shields and using three commonly adopted strategies to evaluate the effectiveness and potential of this strategy. Compared to the base case without radiation shields, inserting one radiation shield with an emissivity of 0.5 enhances the TEG efficiency and system power by 15 % and 9.5 % respectively. The system using the proposed strategy outperforms that using the commonly adopted strategies, especially the strategies of lowering the gap pressure and filling the gap with thermal insulation materials, highlighting the potential of the proposed strategy. Besides, the influences of the shield emissivity and number were studied; from it, less than two radiation shields made by the polished copper are recommended for practical applications.