Multi-mode heat transfer analysis during freezing of an encapsulated storage medium. (May 2015)

• Record Type: Journal Article
• Authors: Archibold, Antonio Ramos; Yogi Goswami, D.; Rahman, Muhammad M.; Stefanakos, Elias K.
• Is Part Of: International journal of heat and mass transfer. Volume 84(2015:May)
• Page Start: 600
• Page End: 609
• Publication Date: 2015-05
• Subjects: Thermal energy storage -- Radiation heat transfer -- Phase change material -- Spherical shell -- Solidification; Heat -- Transmission -- Periodicals; Mass transfer -- Periodicals; Chaleur -- Transmission -- Périodiques; Transfert de masse -- Périodiques; Electronic journals; 621.4022
• DOI: 10.1016/j.ijheatmasstransfer.2014.12.076
• Languages: English
• ISSNs: 0017-9310

Abstract

Abstract: Simultaneous conduction, convection and thermal radiation have been analyzed during the freezing of a non-opaque, non-gray phase change material (PCM) encapsulated in a closed spherical container and heated at relatively high temperatures (250 ⩽ T ⩽ 325 °C). In contrast to the well-known conduction-dominated model of the single phase Stefan problem, in the present study the influence of the participating thermal radiation and the buoyancy induced natural convection within the melt layer is highlighted and analyzed. A two-dimensional, axisymmetric, transient model has been solved numerically. The discrete ordinate method was used to solve the equation of radiative transfer and the finite volume scheme was used to solve the equations for mass, momentum and energy conservation. The effect of additional parameters like the shell size and the external heat transfer coefficient imposed on the outer shell surface as a boundary condition have also been analyzed. It was found that the contribution of thermal radiation on the solidification process of NaNO 3 is to reduce the solidification time by 17% as compared with the limiting case where thermal radiation is neglected.