Melting and solidification enhancement using a combined heat pipe, foil approach

Abstract

Melting and solidification of a phase change material is investigated, experimentally and computationally, using a novel heat pipe-metal foil approach. By embedding a PCM within a metal foil matrix, and delivering (or extracting) thermal energy to (or from) the matrix with a vertically-oriented heat pipe, overall thermal resistances between a working fluid and the PCM solid-liquid interface can be reduced. This leads to increased phase change rates relative to configurations involving only the heat pipe, or only a solid rod of the same physical dimensions as the heat pipe. For a small (approximately 1 percent) volume fraction of foil in the PCM-foil matrix, measured and predicted melting (solidification) rates associated with heat pipe-foil configurations are increased by approximately 300 percent (900 percent) relative to configurations involving the rod with no foil. Melting and solidification rates relative to configurations involving the heat pipe with no foil, are increased by approximately 200 percent and 600 percent. The influence of the heat pipe evaporator-to-condenser length ratio, as well as the overall temperature difference between the working fluid and the PCM fusion temperature, is also reported.

Numerical study of finned heat pipe-assisted thermal energy storage system with high temperature phase change material

“…The results indicated that employing HPs makes considerable improvement in both melting and solidification rates. Sharifi et al [35] investigated the melting and solidification of n-Octadecane (T m = 28°C) using heat http://dx.doi.org/10.1016/j.enconman.2014. 10.053 0196-8904/Ó 2014 Elsevier Ltd. All rights reserved.…”

Heat pipe heat exchangers and heat sinks: Opportunities, challenges, applications, analysis, and state of the art

“…A HP-foil configuration and similarly configured HP-foam system (with aluminum foam replacing the aluminum foil, foam porosities greater than 0.870, and pore densities ranging from 5-40 pores per inch) was also investigated by Allen et al [62,63]. Similar to the results of [61], in [62], the foil-enhanced system (with a porosity of 0.957) exhibited PCM melting (solidification) rates that were nearly 15 (8) times that of the bare rod configuration. The HP-foil system also outperformed the HP-foam system despite the lower porosity (higher metal volume fraction) of the HP-foam system.…”

“…A PCM-HPHX was investigated by Sharifi et al [61] in which a cylinder housed a PCM and a concentrically-located HP. The PCM was further enhanced with aluminum foils (resulting in a PCM-foil matrix porosity of 0.987).…”

Integral Solution of Two-Region Solid–Liquid Phase Change in Annular Geometries and Application to Phase Change Materials–Air Heat Exchangers

“…The integral solution was validated by comparison with computational results obtained from a control volume code based on the temperature transforming method [1]. Validation studies of the code against experimental results has been reported in prior publications by one of the authors [23,24]. Due to the conduction-controlled phase change, the momentum and pressure correction equations where deactivated in the computational model and only the energy equation was solved:…”