Louisville, Kentucky
June 20, 2010
June 20, 2010
June 23, 2010
2153-5965
Mechanical Engineering
12
15.356.1 - 15.356.12
10.18260/1-2--16715
https://peer.asee.org/16715
456
Design of a Flexible Thermoelectric Element
Abstract
Most thermoelectric devices (TEDs) are rigid. Their rigid nature makes them undesirable for adaption to existing structures with confined areas; locations that may experience severe mechanical vibrations; operate in extremely high temperatures; and where rapid temperature drop exists. The TEDs become a constraint when incorporating them in designs with varying contours. A flexible TED design is therefore desired to enable adaption of the devices in more applications. One approach towards the development of a flexible energy harvesting device such as the TED is to develop a flexible thermoelement. Developing a flexible thermoelement is a multi-stage design process. The design has to account for efficiency, structural integrity, and flexibility. This paper addresses the flexibility aspect while future work will include structural integrity by addressing thermal and mechanical loading; and efficiency by addressing materials selection and segmentation to achieve the highest possible power. The paper presents a Finite Element Analysis (FEA) based approach for thermoelement design studying correlation between element length of the cells and heat flux generation within a thermoelectric unit cell. Varying length sizes contribute towards flexibility of the TED. In conclusion, the paper points out how undergraduate students could benefit from exposure and participation in such a design process even though students were not involved in this study originally.
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Introduction
Thermoelectric devices are used in a wide variety of applications for portable or remote power generation, cooling (refrigeration), temperature measurement, and heat pumping. Thermoelectric generators (TEG) provide quiet, solid state, and reliable power that is not adversely affected by harsh conditions such as major changes in temperatures or vibrations. Due to lack of moving parts, TEGs require virtually no maintenance becoming suitable power sources for remote areas such as space and human body. A challenge facing TEGs is their low efficiency due to obtaining their energy from low energy sources such as waste heat and a low figure of merit (ZT) that enable conversion of heat into electricity1. , where T is the absolute conductivity, and k is thermal conductivity. In power generation, the Seebeck effect enables the direct conversion between heat and electric energy streams. Heating one end of the unit cell while holding the other end cooler induces electromotive force within the material and may be harnessed for electrical power2. In Figure 1, two dissimilar semiconductors A and B are connected electrically in series but thermally in parallel with two junctions maintained at different temperatures3. The effect is that a voltage is
Mativo, J., & Sirinterlikci, A. (2010, June), Design Of A Flexible Thermoelectric Element Paper presented at 2010 Annual Conference & Exposition, Louisville, Kentucky. 10.18260/1-2--16715
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