ABSTRACT
Heat pipes are devices that use a small amount of working fluid, typically water, and a wick structure together in a hollow tube hermetically sealed under a vacuum to achieve large increases in the effective thermal conductivity versus that of the tube material alone. Typical copper water heat pipes have an effective thermal conductivity 100–500 times larger than solid copper. It is expected that adding nanoparticles to the working fluid of the heat pipe would increase its thermal conductivity and potentially other kinetic properties of the fluid, thus increasing the performance of the heat pipe. However, little work has been published on nanoparticles in a fluid that changes phase from liquid to vapor in a heat pipe/thermosyphon application. It is not well understood how the rate of vaporization and recondensation of the working fluid would affect the mixing and dispersion of the particles, which is one of the most critical parameters of a nanofluid. Careful experimentation is needed to discover any improvements to the heat pipe performance by the nanofluid.
