Asymptotic analysis of a two-phase Stefan problem in annulus: Application to outward solidification in phase change materials

Abstract We numerically investigate the melting and solidi?cation behavior of phase change materials encapsulated in a small-radii cylinder subjected to a cyclic convective boundary condition (square wave). Initially, we explore the effect of the Stefan and Biot numbers on the non-dimensionalized time required (i.e. reference Fourier number Tref ) for a PCM initially held at Tcold to melt and reach the cross?ow temperature Thot. The increase in either Stefan or Biot number decreases Tref and can be predicted accurately using a correlation developed in this work. The variations of the PCM melt fraction, surface temperature, and heat transfer rate as a function of Fourier number are reported and analyzed for the above process. We further study the effect of the cyclic Fourier number on the periodic melting and freezing process. The melting or freezing front initiates at the outer periphery of the PCM and propagates towards the center. At higher frequencies, multiple two-phase interfaces are generated (propagating inward), and higher overall heat transfer is achieved as the surface temperature oscillates in the vicinity of the melting temperature, which increases the effective temperature difference driving the convective heat transfer.

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A second order accurate fixed-grid method for multi-dimensional Stefan problem with moving phase change materials

Applied Mathematics and Computation ◽

10.1016/j.amc.2021.126719 ◽

2022 ◽

Vol 416 ◽

pp. 126719

Author(s):

S. Nandi ◽

Y.V.S.S. Sanyasiraju

Keyword(s):

Phase Change ◽

Stefan Problem ◽

Phase Change Materials ◽

Grid Method ◽

Second Order ◽

Fixed Grid

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Optimization of the rectification factor of radiative thermal diodes based on two phase-change materials

International Journal of Heat and Mass Transfer ◽

10.1016/j.ijheatmasstransfer.2020.119739 ◽

2020 ◽

Vol 154 ◽

pp. 119739 ◽

Cited By ~ 2

Author(s):

Suraju Olawale Kasali ◽

Jose Ordonez-Miranda ◽

Karl Joulain

Keyword(s):

Phase Change ◽

Phase Change Materials ◽

Two Phase ◽

Rectification Factor

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Exergy analysis of two phase change materials storage system for solar thermal power with finite-time thermodynamics

Renewable Energy ◽

10.1016/j.renene.2011.08.026 ◽

2012 ◽

Vol 39 (1) ◽

pp. 447-454 ◽

Cited By ~ 58

Author(s):

Ya-Qi Li ◽

Ya-Ling He ◽

Zhi-Feng Wang ◽

Chao Xu ◽

Weiwei Wang

Keyword(s):

Phase Change ◽

Finite Time ◽

Phase Change Materials ◽

Exergy Analysis ◽

Storage System ◽

Thermal Power ◽

Solar Thermal ◽

Finite Time Thermodynamics ◽

Two Phase ◽

Solar Thermal Power

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Quasi-approximation for Stefan problem of nearly spherical phase change materials

Journal of Physics Conference Series ◽

10.1088/1742-6596/1324/1/012069 ◽

2019 ◽

Vol 1324 ◽

pp. 012069

Author(s):

Jiayan Li ◽

Yue Chan

Keyword(s):

Phase Change ◽

Stefan Problem ◽

Phase Change Materials

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Experimental Study on Solar Heat Battery using Phase Change Materials for Parabolic Dish Collectors

International Journal of Renewable Energy Development ◽

10.14710/ijred.2021.38376 ◽

2021 ◽

Vol 10 (4) ◽

pp. 819-825

Author(s):

Ramalingam Senthil ◽

Inbaraj Infanta Mary Priya ◽

Mukund Gupta ◽

Chinmaya Rath ◽

Nilanshu Ghosh

Keyword(s):

Phase Change ◽

Phase Change Materials ◽

Population Increase ◽

Two Phase ◽

Thermo Electric ◽

Solar Heat ◽

Complete Melting ◽

Parabolic Dish ◽

Present Design ◽

Outdoor Test

Energy consumption has increased withthe population increase, and fossil fuel dependency has risen and causing pollutions. Solar energy is suitableto provide society's thermo-electric needs. Thermal energy storage-based concentrated solar receivers are aimed at store heat energy and transportable to the applications. Acavity receiver with two-phase change materials (PCM) is experimentally investigated using a parabolic dish collector to act as the solar heat battery. The selected PCMs are MgCl2.6H2O and KNO3-NaNO3. PCMs are chosen and placed as perthe temperature zones of the receiver. The outdoor test wasconductedto determine the conical receiver's storage performance using cascaded PCMs. The complete melting of PCM attainsat an average receiver surface temperature of 230°C. The complete melting of the PCM in the receiver took around 30 minutes at average radiation around 700 W/m2, and heat stored is approximately 5000 kJ. The estimated number of cavity receivers to be charged on a sunny day is about 10-15 according to the present design and selected PCMs, for later use

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One-dimensional Stefan problem formulation for solidification of nanostructure-enhanced phase change materials (NePCM)

International Journal of Heat and Mass Transfer ◽

10.1016/j.ijheatmasstransfer.2013.07.095 ◽

2013 ◽

Vol 67 ◽

pp. 202-213 ◽

Cited By ~ 18

Author(s):

Yousef M.F. El Hasadi ◽

J.M. Khodadadi

Keyword(s):

Phase Change ◽

Stefan Problem ◽

Phase Change Materials ◽

Problem Formulation ◽

One Dimensional

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Conductive thermal diode based on two phase-change materials

International Journal of Thermal Sciences ◽

10.1016/j.ijthermalsci.2020.106393 ◽

2020 ◽

Vol 153 ◽

pp. 106393 ◽

Cited By ~ 1

Author(s):

Suraju Olawale Kasali ◽

Jose Ordonez-Miranda ◽

Karl Joulain

Keyword(s):

Phase Change ◽

Phase Change Materials ◽

Two Phase

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Preparation of n-Alkane/Polycaprolactone Phase-Change Microcapsules via Single Nozzle Electro-Spraying: Characterization on Their Formation, Structures and Properties

Applied Sciences ◽

10.3390/app10020561 ◽

2020 ◽

Vol 10 (2) ◽

pp. 561 ◽

Cited By ~ 2

Author(s):

Shengchang Zhang ◽

Christine Campagne ◽

Fabien Salaün

Keyword(s):

Energy Storage ◽

Phase Change ◽

Phase Change Materials ◽

High Efficiency ◽

Two Phase ◽

Structures And Properties ◽

The Matrix ◽

Ft Ir ◽

The Mean ◽

Poly Caprolactone

The phase change microcapsule (mPCM) is one of the primary candidates in the fields of energy storage and thermal regulation. In this study, electro-spraying, as a green, high-efficiency electrohydrodynamic atomization technology, is applied to the microencapsulation of two phase change materials (PCM) (n-hexadecane and n-eicosane) with three loading contents (30%, 50%, and 70% by weight) in a polycaprolactone matrix. Ethyl acetate (EA) and chloroform (Chl) were chosen as solvents to prepare the working solutions. The objective of this study is to clarify the microencapsulation process during electro-spraying and to optimize the structure and properties of the electro-sprayed mPCM. The structures, morphologies, and thermal properties of the mPCM were characterized by optical microscopy (OM), scanning electron microscopy (SEM), differential scanning calorimeter (DSC), thermogravimetric analysis (TGA), and fourier transform infrared spectroscopy (FT-IR). Electro-sprayed spherical and non-porous mPCM have been successfully prepared. The mean diameter and the particle size distribution depend mainly on the choice of the n-alkane, as well as the solvent used to prepare the working solutions. Meanwhile, the structure formation of electro-sprayed mPCM and the loading content of PCM were mainly influenced by the evaporation of the solvent and the phase separation between PCM and poly(caprolactone) (PCL) matrix. During the shell formation or PCL solidification, the control of the PCM leaching out of the matrix allows improving the loading content. Finally, based on a high latent heat and simple formation process, the electro-spraying route of PCM is a green, non-toxic, and high-efficiency direction for energy storage and heat regulation.

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