Expanding the reduced-current approach for thermoelectric generators to achieve higher volumetric power density

Abstract

Thermoelectrics are candidate niche electrical generator devices for energy management. At present, scientists are more focused on thermoelectric (TE) material development, but the TE module design procedure is still in a relatively virgin state. One of the most well-known methods is the reduced current approach (RCA) for TE module design, where the same current is induced through the p and n legs of the thermoelectric generator (TEG). The current density of each element is manipulated by changing the area of both legs. This technique leads to a TE module architecture based on the most efficient configuration of both p and n legs. In the current paper, we apply an extended version of this technique, to show how a TE module with a higher volumetric power density can be designed, compared to the original RCA. Our studies indicate that for some combinations of p and n material properties, optima yielding significant material savings without compromising power output can be determined. The current study has been directed towards obtaining high power output from high-temperature TEGs, rather than focusing on efficiency enhancement.

Simple engineering design for complex thermoelectric generators based on reduced current approach

“…Therefore, by (11), (12), (16) and (17), the heat fluxes (Q ) through each P and N leg can be calculated as follows (Appendix B): By using Equations (13), (14), (18) and (19) the current density in each P and N leg is (Appendix B):…”

“…Therefore, (11), (12) and (23) provide the architecture of the TEG, and (22) and (25) provide the output of the TEG.…”

“…The most efficient area of N and P legs can be calculated as in section 2.2.1 by (10)e (12). Considering conditions where the TEG operates at its highest efficiency, by we can calculate the most efficient current density through the P and N legs by (23), (26) and (27).…”

“…McCarty [11] discussed effects of electrical and thermal load resistance ratios on TEG system, and implied that the both load resistance ratios should operate under the same value which is ffiffiffiffiffiffiffiffiffiffiffiffiffiffi 1 þ zT p . Conversely Wijesekara et al [12] introduce a new optimization strategy for TEGs which based on TE material properties and define when TEG design should focus on highest efficiency and when TEG design should focus on highest power. Schilz et al [13] has presented an optimization process for graded TE devices with considering the importance of the electrical current density.…”

Compatibility approach for the improvement of oxide thermoelectric converters for industrial heat recovery applications

“…More details and model calculations can be found elsewhere. [30][31][32] In a thermoelectric converter, the same electrical current I ¼ J p A p ¼ ÀJ n A n flows in both legs, and thus,…”