Thermal and stress analyses in thermoelectric generator with tapered and rectangular pin configurations. (1st November 2016)

• Record Type: Journal Article
• Authors: Yilbas, Bekir Sami; Akhtar, S.S.; Sahin, A.Z.
• Is Part Of: Energy. Volume 114(2016)
• Page Start: 52
• Page End: 63
• Publication Date: 2016-11-01
• Subjects: Thermoelectric generator -- Thermal stress -- Pin geometry -- Tapered pins; Power resources -- Periodicals; Power (Mechanics) -- Periodicals; Energy consumption -- Periodicals; 333.7905
• DOI: 10.1016/j.energy.2016.07.168
• Languages: English
• ISSNs: 0360-5442

Abstract

Abstract: Thermal stress developed in thermoelectric generators is critical for long service applications. High temperature gradients, due to a large temperature difference across the junctions, causes excessive stress levels developed in the device pins and electrodes at the interfaces. In the present study, a thermoelectric generator with horizontal pin configuration is considered and thermal stress analysis in the device is presented. Ceramic wafer is considered to resemble the high temperature plate and copper electrodes are introduced at the pin junctions to reduce the electrical resistance between the pins and the high and low temperature junction plates during the operation. Finite element code is used to simulate temperature and stress fields in the thermoelectric generator. In the simulations, convection and radiation losses from the thermoelectric pins are considered and bismuth telluride pin material with and without tapering is incorporated. It is found that von Mises stress attains high values at the interface between the hot and cold junctions and the copper electrodes. Thermal stress developed in tapered pin configuration attains lower values than that of rectangular pin cross-section. Highlights: Different cold junction temperatures improves thermoelectric generator performance. von Mises stress remains high across copper electrodes and hot junction ceramics. von Mises stress reduces along pin length towards cold junction. Pin tapering lowers stress levels in thermoelectric generator.