Reprocessing Leading to Lower Thermal Conductivity of ZnO Thermoelectrics | Chapter 06 | New Advances in Materials Science and Engineering Vol. 2

Nanometer sized ZnO powder was co-doped with gamma aluminum oxide and gallium oxide and sintered using a direct current sintering furnace. Sintered samples were reprocessed by crushing the samples in a Carver press, then milling for 4 hours. The reprocessed samples were then re-sintered in the direct current sintering furnace. Heat capacity, density and thermal diffusivity were measured in order to determine thermal conductivity as a function of temperature. Thermoelectric properties were measured. It was found that the thermal conductivity decreased from 7 W/m K to 3.5 W/m K at 805K by using the reprocessing technique. It is projected that the value will be less than 2 W/m K and the figure of merit greater than 0.65 at 1400K.

Author(s) Details

D. S. Tucker
EM32, Marshall Space Flight Center, MSFC, Alabama, USA.

A. O’Connor
School of Nuclear Engineering, Purdue University, West Lafayette, Indiana, USA.

C. Romnes
Department of Nuclear Engineering, University of New Mexico, Albuquerque, Mexico.

C. Hill
EM32, Marshall Space Flight Center, MSFC, Alabama, USA.

X. Zhou
Department of Metallurgical and Materials Engineering, Tuscaloosa, Alabama, USA.

G. Thompson
Department of Metallurgical and Materials Engineering, Tuscaloosa, Alabama, USA.

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Analytical Modeling of the Thermoelectric Effect in Photovoltaic Cells: Combined Solar Photovoltaic and Thermoelectric Generator System (PV+TEG) | Chapter 05 | Advances in Mathematics and Computer Science Vol. 2

Aims: Analytical modeling of the combined systems photovoltaic-thermoelectric (PV + TEG). The advantage of these systems is double:

  • On the one hand, they allow to cool the photovoltaic cells (PV), which avoids the loss of electrical efficiency observed in the devices,
  • On the other hand, recover this lost energy in the form of heat, and transform it into electrical energy thanks to the thermoelectric modules operating in Seebeck mode.

Study Design: Laboratory of Radiation Physics LPR, FAST-UAC, 01 BP 526, Cotonou, Benin. Department of Physics (FAST) and Doctoral Formation Materials Science (FDSM), University of Abomey-Calavi, Benin.

Methodology: We considered the temperature distribution in the semiconductor plate of the Thermoelectric Generator System (TEG). We resolved the thermal conductivity equation described by:

Where  a^2 is the thermal diffusivity, Q(x, y, z) is the heat flow going from the PV to the TEG module which is dissipated through the latter; using constants variation method. We assumed that the temperature along the y-axis is considered uniform.

Results: The results obtained show that, the temperature distribution in the form of a traveling wave is maintained by external heating. This depends on both the hot and cold side temperature and the temperature span.

Conclusion: The heat flux available at the hot side of the TEG is assumed to be what remains of the absorbed radiation of the PV power production.

Author(s) Details

Géraud F. Hounkpatin
Département de Physique (FAST) et Formation Doctorale Sciences des Matériaux (FDSM), Université d’Abomey-Calavi, Bénin.
Laboratoire de Physique du Rayonnement LPR, FAST-UAC, 01 BP 526 Cotonou, Bénin.

Macaire Agbomahéna
Laboratoire de Physique du Rayonnement LPR, FAST-UAC, 01 BP 526 Cotonou, Bénin.
Laboratoire de Caractérisation Thermophysique des Matériaux et Appropriation Energétique (Labo CTMAE/EPAC/UAC), Abomey-Calavi, Bénin.

Basile B. Kounouhéwa
Département de Physique (FAST) et Formation Doctorale Sciences des Matériaux (FDSM), Université d’Abomey-Calavi, Bénin.
Laboratoire de Physique du Rayonnement LPR, FAST-UAC, 01 BP 526 Cotonou, Bénin.
Centre Béninois de la Recherche Scientifique et Technique (CBRST), 03 BP 1665 Cotonou, Bénin.

Vianou I. Madogni
Département de Physique (FAST) et Formation Doctorale Sciences des Matériaux (FDSM), Université d’Abomey-Calavi, Bénin.
Laboratoire de Physique du Rayonnement LPR, FAST-UAC, 01 BP 526 Cotonou, Bénin.

Antoine Vianou
Laboratoire de Caractérisation Thermophysique des Matériaux et Appropriation Energétique (Labo CTMAE/EPAC/UAC), Abomey-Calavi, Bénin.

Cossi N. Awanou
Département de Physique (FAST) et Formation Doctorale Sciences des Matériaux (FDSM), Université d’Abomey-Calavi, Bénin.
Laboratoire de Physique du Rayonnement LPR, FAST-UAC, 01 BP 526 Cotonou, Bénin.

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