Ramousse Julien, Goupil Christophe
Laboratoire Optimisation de la Conception et Ingénierie de l'Environnement (LOCIE), Université Savoie Mont Blanc, UMR 5271 Le Bourget du Lac, France.
Laboratoire Interdisciplinaire des Energies de Demain (LIED), Université Paris Diderot, UMR 8236 Paris, France.
Entropy (Basel). 2018 Sep 3;20(9):666. doi: 10.3390/e20090666.
Thermoelectric system's operation needs careful attention to ensure optimal power conversion depending on the application aims. As a ternary diagram of bithermal systems allows a synthetic graphical analysis of the performance attainable by any work-heat conversion system, thermoelectric systems operation is plotted as a parametric curve function of the operating conditions (electric current and reservoirs' temperature), based on the standard model of Ioffe. The threshold of each operating mode (heat engine, heat pump, thermal dissipation, and forced thermal transfer), along with the optimal efficiencies and powers of the heat pump and heat engine modes, are characterized graphically and analytically as a function of the material properties and the operating conditions. The sensibility of the performance aims (maximum efficiency vs. maximum power) with the operating conditions is, thus, highlighted. In addition, the specific contributions of each phenomenon involved in the semiconductor (reversible Seebeck effect, irreversible heat leakage by conduction and irreversible thermal dissipation by Joule effect) are discussed in terms of entropy generation. Finally, the impact of the exo-irreversibilities on the performance is analyzed by taking the external thermal resistances into account.
热电系统的运行需要仔细关注，以根据应用目的确保实现最佳功率转换。由于双热系统的三元图允许对任何功热转换系统可达到的性能进行综合图形分析，基于伊夫（Ioffe）的标准模型，热电系统的运行被绘制为运行条件（电流和储热器温度）的参数曲线函数。每个运行模式（热机、热泵、热耗散和强制热传递）的阈值，以及热泵和热机模式的最佳效率和功率，都通过图形和解析的方式表征为材料特性和运行条件的函数。因此，性能目标（最大效率与最大功率）对运行条件的敏感性得以凸显。此外，从熵产生的角度讨论了半导体中涉及的每种现象（可逆塞贝克效应、传导引起的不可逆热泄漏和焦耳效应引起的不可逆热耗散）的具体贡献。最后，通过考虑外部热阻来分析外部不可逆性对性能的影响。
