Premium
Optimally Distributed Transport Properties Can Produce Highest Performance Thermoelectric Systems
Author(s) -
Bell Lon E.
Publication year - 2019
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201900562
Subject(s) - carnot cycle , fabrication , thermoelectric effect , spark plasma sintering , materials science , figure of merit , thermoelectric materials , energy conversion efficiency , coefficient of performance , refrigeration , thermal conductivity , energy transformation , engineering physics , optoelectronics , sintering , mechanical engineering , thermodynamics , composite material , engineering , heat exchanger , physics , medicine , refrigerant , alternative medicine , pathology
Optimum cooling of conventional thermoelectric (TE) devices is limited to about ⅙ Carnot efficiency for TE materials with figure of merit, ZT ≈ 1. This is ¼ to ½ the efficiency of typical two‐phase refrigeration systems and limits the use of TE materials to specialized applications where a combination of small size, solid‐state operation, and simplicity outweighs device performance limitations. Similarly, TE heating and power generation systems exhibit low efficiency in comparison with most current energy conversion systems. Herein, it is shown that performance efficiencies of TE couples with suitable distributed transport properties (DTP) exceed those of all other TE systems. TE material fabrication methods, including spark plasma sintering, additive manufacturing, and nanoscale material production processes, are evolving, making TE materials with controlled spatially dependent properties more practical to fabricate. Therefore, it is important to determine the performance advantages achievable through the fabrication of such TE couples. Governing equations for the optimum performance of DTP TE systems are derived and solved in a closed analytical form for the spatially dependent Seebeck coefficient, thermal conductivity, and electrical resistivity. Results are presented as analytical solutions for optimum efficiency, optimum spatial distribution of DTP properties, and other operating conditions of interest.