Two-phase nanofluid-based thermal management systems for LED cooling

V Kiseev,D Aminev,O Sazhin

doi:10.1088/1757-899x/192/1/012020

V Kiseev, D Aminev + Show 1 more

Open Access

https://doi.org/10.1088/1757-899x/192/1/012020

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Abstract

This research focuses on two-phase thermal control systems, namely loop thermosyphons (LTS) filled with nanofluids, and their use as LED cooling devices. The behavior of the fluid in the thermosyphons and the mechanisms explaining the possible impact of nanoparticles on thermal properties of the working fluid as well as the processes in the LTS are addressed. Nanoparticle distribution in the nanofluid, methods of preparation of nanofluids and nanofluid degradation processes (aging) are studied. The results are obtained from a set of experiments on thermosyphon characteristics depending on the thermophysical properties of the working fluid, filling volume, geometry and materials of radiators. The impact of nanofluids on heat-transfer process occurring inside thermosyphon is also studied. Results indicate strong influence of nanoparticles on the thermal properties of the thermosyphons, with up to 20% increase of the heat transfer coefficient. Additionally, a method of calculating the hydrodynamic limit of the LTS is proposed, which allows for estimation of the maximum heat flux that can be transferred by means of the LTS. Possible ways for further improvement of the model are proposed. The nanofluids are shown to be effective means of enhancing two-phase systems of thermal management.

Highlights

Two-phase heat transfer systems are widely used in different technical devices, especially in spacecraft thermal control systems, as well as in electronic devices such as microprocessors, semiconductor power electronics, modern powerful laser sources, optoelectronic devices, light-emitting diode (LED) lighting [1,2,3], etc
Experimental study assumes obtaining temperatures at specific points on a loop thermosyphon depending on the nominal load of LEDs or heat load, both measured in Watts
We have proposed a model for calculating maximal heat flux based on the thermal properties of working fluids and height difference between the evaporator and the condenser

Summary

Introduction

Two-phase heat transfer systems are widely used in different technical devices, especially in spacecraft thermal control systems, as well as in electronic devices such as microprocessors, semiconductor power electronics, modern powerful laser sources, optoelectronic devices, light-emitting diode (LED) lighting [1,2,3], etc.Recent findings indicate that a new type of liquids with addition of metal or metal oxide nanoparticles may enhance thermal characteristics of two-phase systems. Over the last 12 years, extensive studies of nanofluids have been conducted containing both positive and negative results of the use of nanoparticles in heat transfer systems. Effect of nanoparticles on the system parameters is characterized by change of thermal resistance, critical heat flux, heat transfer coefficient, thermal conductivity, intensification of boiling and changes in the operating mode of the system.

Results

Conclusion