The melting process of storage materials with relatively high phase change temperatures in partially filled spherical shells
The melting process of storage materials with relatively high phase change temperatures in partially filled spherical shells
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DOI：
10.1016/j.apenergy.2013.11.048
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发表时间：
2014-03
期刊：
影响因子：
11.2
通讯作者：
Antonio Ramos Archibold;J. González-Aguilar;M. M. Rahman-M.;D. Goswami;M. Romero;E. Stefanakos
中科院分区：
文献类型：
--
作者：
Antonio Ramos Archibold;J. González-Aguilar;M. M. Rahman-M.;D. Goswami;M. Romero;E. Stefanakos
分析了球形潜热蓄热胶囊内熔化过程的传热和流体流动的二维轴对称模型。在胶囊内提供了一个空隙空间，以考虑PCM的体积膨胀。采用有限体积法求解数学模型，采用焓-孔隙率公式求解PCM液固两区能量方程。研究了不同粒径（20、30、40和50 mm）胶囊的Grashof数和Stefan数对其热性能的影响。结果表明，将Grashof数从1.32 × 104增加到2。06 × 105增强传热。当斯戴芬数从0.077增加到0.097时，当斯戴芬数为9.09 × 104时，PCM的熔化速度加快。最后，引入适当的基于傅里叶数、Grashof数和Stefan数组合的无因次变量，以获得硝酸钠熔化过程中液体质量分数与努塞尔数的广义相关性。
A two dimensional axisymmetric model of the heat transfer and fluid flow during the melting process inside a spherical latent heat thermal storage capsule is analyzed. A void space was provided within the capsule to take into account the volumetric expansion of the PCM. The mathematical model was solved using the finite-volume method, and the enthalpy-porosity formulation was employed to solve the energy equations in both the liquid and solid regions of the PCM. The effects of the Grashof and Stefan numbers on the thermal performance of the capsules of various diameters (20, 30, 40 and 50 mm) have been investigated. It was found that increasing the Grashof number from 1.32 × 104to 2. 06 × 105enhances the heat transfer. Also for a constant Grashof number (9.09 × 104) the PCM melts at a faster rate when the Stefan number increases from 0.077 to 0.097. Finally, appropriate dimensionless variables based on a combination of the Fourier, Grashof and Stefan numbers are introduced in order to obtain a generalized correlation for the liquid mass fraction and the Nusselt number during melting of sodium nitrate.