Modeling and optimization of hybrid solar thermoelectric systems with thermosyphons
Name
Modeling and Optimization of Hybrid Solar Thermoelectric Systems with Thermosyphons.pdf
Description
Main article, figures, and supplementary information
Size
3.6 MB
Format
Adobe PDF
Checksum (MD5)
c63ac6ae11d24595006ce9ee77de0d2f
Author(s)
Miljkovic, Nenad
Wang, Evelyn N.
Date Issued
November 2011
Journal
Solar Energy
Publisher
Elsevier
Citation
Miljkovic, Nenad, and Evelyn N. Wang. “Modeling and Optimization of Hybrid Solar Thermoelectric Systems with Thermosyphons.” Solar Energy 85, no. 11 (November 2011): 2843–2855.
Version
Author's final manuscript
Abstract
We present the modeling and optimization of a new hybrid solar thermoelectric (HSTE) system which uses a thermosyphon to passively transfer heat to a bottoming cycle for various applications. A parabolic trough mirror concentrates solar energy onto a selective surface coated thermoelectric to produce electrical power. Meanwhile, a thermosyphon adjacent to the back side of the thermoelectric maintains the temperature of the cold junction and carries the remaining thermal energy to a bottoming cycle. Bismuth telluride, lead telluride, and silicon germanium thermoelectrics were studied with copper–water, stainless steel–mercury, and nickel–liquid potassium thermosyphon-working fluid combinations. An energy-based model of the HSTE system with a thermal resistance network was developed to determine overall performance. In addition, the HSTE system efficiency was investigated for temperatures of 300–1200 K, solar concentrations of 1–100 suns, and different thermosyphon and thermoelectric materials with a geometry resembling an evacuated tube solar collector. Optimizations of the HSTE show ideal system efficiencies as high as 52.6% can be achieved at solar concentrations of 100 suns and bottoming cycle temperatures of 776 K. For solar concentrations less than 4 suns, systems with thermosyphon wall thermal conductivities as low as 1.2 W/mK have comparable efficiencies to that of high conductivity material thermosyphons, i.e. copper, which suggests that lower cost materials including glass can be used. This work provides guidelines for the design, as well as the optimization and selection of thermoelectric and thermosyphon components for future high performance HSTE systems.
MIT Department
Massachusetts Institute of Technology. Department of Mechanical Engineering
Massachusetts Institute of Technology. Device Research Laboratory
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Creative Commons Attribution-NonCommercial-NoDerivs License
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DOI of Published Version
https://doi.org/10.1016/j.solener.2011.08.021
