A finite element modeling of thermal conductivity of fabrics embedded with phase change material

Abstract

The thermal capacitance of a fabric is increased when the fabric is embedded with a phase change material (PCM). This is due to utilizing the latent heat release or absorption of the PCM during its phase change process. This article presents a modified finite element method algorithm based on the Galerkin weak formulation with quadratic shape functions. The modification correctly models the phase change process. A diver's dry suit made from four types of garments, 1-layer Thinsulate, 1-layer PCM, and 2-layer and 4-layer Thinsulate-PCM composites, are investigated using the modified finite element method. Temperature profiles and heat fluxes are compared with and are shown to be superior to results obtained using a finite difference procedure. References

• D. P. Colvin and Y. G. Bryant. Protective clothing containing encapsulated phase change materials. Advances in Heat and Mass Transfer in Biotechnology, HD-Vol. 362/BED-Vol. 40:123--132,1998.
• J. A. Gear, M. J. Lachut and Y. Ding. Enchanced thermal performance of garments embeded with encapsulated phase change material. ANZIAM J., 47(EMAC2005):C137--C151, 2006. http://anziamj.austms.org.au/V47EMAC2005/Gear
• J. M. Hill and J. N. Dewynne. Heat Conduction. Applied mathematics and engineering science texts. Blackwell Scientific Publications, 1987.
• D. C. Hittle and T. L. Andre. A new test instrument and procedure for evaluation of fabrics containing phase-change material. ASHRAE Transactions, 4509:175--182, 2002.
• G. E. R. Lamb and K. Duffy-Morris. Heat loss through fabrics under ventilation with and without a phase transition additive. Textile Research Journal, pages 261--265, ISSN:0040-5175.
• G. A. Lane. Solar heat storage: latent heat material. Vol. I, CRC Press, Boco Raton, Florida, 1983.
• G. N. Mercer, and H. S. Sidhu. Mathematical modelling of the effect of fire exposure on a new type of protective clothing. To appear in ANZIAM J., V49. Proceedings of the 8th Biennial Engineering Mathematics and Applications Conference, EMAC-2007. Editors G. N. Mercer and A. J. Roberts.
• M. L. Nuckols. Analytical modeling of a diver dry suit enhanced with micro-encapsulated phase change materials. Ocean Engineering, 26:547--564, 1999. doi:10.1016/S0029-8018(98)00001-8
• O. C. Zienkiewicz, R. L. Taylor, and J. Z. Zhu. The finite element method: its basis and fundamentals, sixth edition, Elsevier Butterworth--Heinemann 2005. ISBN 0750663200