Experimental Study on Boiling of Nanofluids in Copper Foam

TL;DR

This study experimentally examines how nanofluids boil within copper foam, revealing a gravity-independent liquid squeezing phenomenon and proposing a device to mitigate nanoparticle clogging in heat pipes.

Contribution

It introduces an experimental analysis of nanofluid boiling in copper foam and proposes a novel device to address nanoparticle accumulation in heat pipe wicks.

Findings

Liquid is squeezed out along the boundary during boiling.

The phenomenon is independent of gravity.

A device is designed to redirect squeezed-out liquid.

Abstract

Nanofluids are suspensions of nanoscale particles (such as metals and their oxides) in base fluids (such as water, oil, or alcohol), which can significantly enhance the heat transfer performance of the base fluid. However, when nanofluids are applied to heat pipes, it is common for nanoparticles to accumulate within the heat pipe's capillary wick, clogging it and increasing thermal resistance. This paper investigates the phenomenon of boiling of water and nanofluids enhanced by copper foam through experimental methods. When the liquid is injected into copper foam placed on a heating plate, some of the liquid is squeezed out along the boundary of the heated surface of the copper foam during boiling. This phenomenon is independent of gravity but related to the hydrophilicity or hydrophobicity of the heating surface. Based on these properties, we design a device to guide the squeezed-out liquid to other locations, offering a promising solution to the problem of nanoparticle accumulation in the heat pipe's capillary wick.