Numerical Study of Natural Convection Effects in Latent Heat Storage using Aluminum Fins and Spiral Fillers

A numerical investigation has carried out to understand the melting characteristics of phase change material (PCM) in a fin type latent heat storage with the addition of embedded aluminum spiral fillers. It is known that melting performance of PCM can be significantly improved by increasing the number of embedded metallic fins in the latent heat storage system but to certain values where only lead to small improvement in heat transfer rate. Hence, adding aluminum spiral fillers within the fin gap can be an option to improve heat transfer internally. This paper presents extensive computational visualizations on the PCM melting patterns of the proposed fin-spiral fillers configuration. The aim of this investigation is to understand the PCM-s melting behaviors by observing the natural convection currents movement and melting fronts formation. Fluent 6.3 simulation software was utilized in producing twodimensional visualizations of melting fractions, temperature distributions and flow fields to illustrate the melting process internally. The results show that adding aluminum spiral fillers in Fin type latent heat storage can promoted small but more active natural convection currents and improve melting of PCM.





References:
[1] Morisson, Abdel-Kalik, 1978. Effect of phase-change energy storage on
the performance of air-based and liquid-based solar heating sytems.
Solar Energy 20: 57-67.
[2] A.A. Ghoneim, 1989. Comparison of theoretical models of phase-change
and sensible heat storage for air and water-based solar heating systems.
Solar Energy 42(3): 209-20.
[3] A. G. Evans, M.Y. He, Hutchinson J.W., Shaw M., 2001. Temperature
distribution in advanced power electronics systems nd the effect of phase
change materials on temperature supprression during power pulses. J.
Electron. Packag.-Trans. ASME 123: 211-217.
[4] S. Jegadheeswaram, S.D. Pohekar, 2009. Performance enhancedment in
latent heat thermal storage system: A review. Renewable and
Sustainable Energy Reviews 13: 2225-2244.
[5] S.M. Hasnain, 1998. Review on sustainable thermal storage
technologies, Part 1: Heat storage materials and techniques. Energy
Convers Mgmt 39: 1127-3-1138.
[6] M. Gharebagi, I. Sezai, 1997. Enhancement of heat transfer in latent heat
storage modules with internal fins. Numer Heat Transf Part A 53: 749-
765.
[7] P. Lamberg, K. Siren, 2004. Numerical and experimental investigation of
melting and freezing processes in phase change material storage. Int J.
Therm Sci 43: 277-287.
[8] Y. Jellouli, R. Chouikh, A. Guizani, A. Belghith, 2007. Numerical study
of the moving boundary problem during melting process in a rectangular
cavity heated from below. Am J. App Sci 4: 251-256.
[9] W.R. Humphries, E.I. Griggs, 1977. A design handbook for phase
change thermal scontrol and energy storage devices. NASA Technicsal
Paper 1074, NASA Scientific and Technical Information Office.
[10] R. Reid, J. Prausnitz, B. Poling, 1987. The Properties of Gases and
Liquids, McGraw-Hill, New Yorok.
[11] V. Shatikan, G. Ziskind, R. Letan, Numerical investigation of a PCMbased
heat sink with internal fins. Int. J. Heat and Mass Transfer 48
(2005) 3689-3706.
[12] A.D. Brent, V.R. Voller, K.J. Reid, 1988. Enthalpy-porosity technique
for modeling convection-diffusion phase change: Application to the
melting of a pure metal, Numer. Heat Transfer 13: 297-318.
[13] ANSYS Inc., ANSYS Fluent 12.0 User-s Guide, 2009