Purdue University Graduate School
Design And Fabrication Of A Hybrid Nanoparticle-Wick Heat Sink Structure For Thermoelectric Generators In Low-Grade Heat Utilization.pdf (2.56 MB)

Design And Fabrication Of A Hybrid Nanoparticle-Wick Heat Sink Structure For Thermoelectric Generators In Low-Grade Heat Utilization

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posted on 2019-10-30, 15:37 authored by Michael D OzehMichael D Ozeh
Waste heat recovery is a multi-billion-dollar industry with a compound annual growth rate of 8.8% assessed between 2016 to 2024 and low-grade waste heat (< 230oC ± 20oC) makes up 66% of this ubiquitous resource. Thermoelectric generators are preferred for the recovery process because they are cheap and are well suited for this temperature range. They generate power by converting thermal potential to electric potential, known as the Seebeck effect. Since they have no moving parts, they are inherently immune to mechanical failure or an intermittent need for maintenance. However, the challenge has been to effectively harvest waste heat with these modules to generate power, using passive processes. This work is focused on designing a device for optimized harvesting of waste energy from the ambient with a custom, evaporatively-cooled heat sink. This heat sink is designed to passively handle the cooling of the other side of the thermoelectric module so as to enable the attainment of a minimum of 5V, which is the minimum voltage required to power small mobile devices. The heat sink model is similar to a loop heat pipe but engineered for compactness. To ensure this level of efficacy is attained, several studies are made to optimize the wick. Non-metal wicks were considered as they do not contribute to an increase in temperature of the compensation chamber in loop heat pipes. A non-metal wick integrated with nanoparticles is tested and results show a clear thermal management enhancement over similar but virgin non-metal wicks, at over 16%. The heat source section of the device is optimized for energy-harvesting in low grade temperature regimes by incorporating a near-black body coating on the metal heat source section. Experimental results show that both the heat source and sink sections were able to induce sufficient thermal potential for the thermoelectric modules to passively generate up to 5V using eight 40mm by 40mm Bismuth Telluride modules in 3.5 minutes. The prototype is relatively cheap, inherently reliable and presents the possibility of passively harvesting low-grade waste heat for later use, including powering small electronic devices.


Purdue Water Institute


Degree Type

  • Master of Science in Mechanical Engineering


  • Mechanical Engineering

Campus location

  • Hammond

Advisor/Supervisor/Committee Chair

A. G. Agwu Nnanna

Advisor/Supervisor/Committee co-chair

Harvey Abramowitz

Additional Committee Member 2

Chandramouli Viswanatha Chandramouli

Additional Committee Member 3

Nuri Zeytinoglu