Phase Change Heat Transfer During Melting and Resolidification of Melt Around Cylindrical Heat Source(s)/Sink(s)

1989 ◽  
Vol 111 (1) ◽  
pp. 43-49 ◽  
Author(s):  
K. Sasaguchi ◽  
R. Viskanta
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Phase Change Material ◽  
Liquid Interface ◽  
Cylinder Surface ◽  
Storage Unit ◽  
Energy Storage Unit ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Change Material

Melting and resolidification of a phase change material around two cylindrical heat exchangers spaced vertically have been investigated experimentally. Experiments have been performed to examine the effects of the cylinder surface temperatures on heat transfer during the melting and freezing cycle. The processes have been clarified on the basis of observations of timewise variations in the solid/liquid interface and of temperature distribution measurements in the phase change material. The results show that the solid/liquid interface contour during the melting and resolidification of the liquid from the upper cylinder is greatly affected by the surface temperature of the lower cylinder. The results show that multiple liquid regions may develop in the phase change material around the embedded heat sources/sinks, and the temperature swings and melting and freezing periods need to be selected properly in order to effectively utilize the phase change material in a latent heat energy storage unit.

scholarly journals Approximate Analytical Solution for One-Dimensional Solidification Problem of a Finite Superheating Phase Change Material Including the Effects of Wall and Thermal Contact Resistances

2012 ◽  
Vol 2012 ◽  
pp. 1-20 ◽  
Author(s):  
Hamid El Qarnia ◽  
Fayssal El Adnani ◽  
El Khadir Lakhal
Keyword(s):  
Analytical Solution ◽  
Phase Change ◽  
Phase Change Material ◽  
Liquid Interface ◽  
Solid Shell ◽  
Interface Position ◽  
Temperature Distributions ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Change Material

This work reports an analytical solution for the solidification of a superheating phase change material (PCM) contained in a rectangular enclosure with a finite height. The analytical solution has been obtained by solving nondimensional energy equations by using the perturbation method for a small perturbation parameter: the Stefan number,ε. This analytical solution, which takes into account the effects of the superheating of PCM, finite height of the enclosure, thickness of the wall, and wall-solid shell interfacial thermal resistances, was expressed in terms of nondimensional temperature distributions of the bottom wall of the enclosure and both PCM phases, and the dimensionless solid-liquid interface position and its dimensionless speed. The developed solution was firstly compared with that existing in the literature for the case of nonsuperheating PCM. The predicted results agreed well with those published in the literature. Next, a parametric study was carried out in order to study the impacts of the dimensionless control parameters on the dimensionless temperature distributions of the wall, the solid shell, and liquid phase of the PCM, as well as the solid-liquid interface position and its dimensionless speed.

Large-Scale Experimental Study of a Phase Change Material: Shape Identification for the Solid–Liquid Interface

2015 ◽  
Vol 36 (10-11) ◽  
pp. 2897-2915 ◽  
Author(s):  
Soumaya Kadri ◽  
Belgacem Dhifaoui ◽  
Yvan Dutil ◽  
Sadok Ben Jabrallah ◽  
Daniel R. Rousse
Keyword(s):  
Experimental Study ◽  
Phase Change ◽  
Phase Change Material ◽  
Large Scale ◽  
Liquid Interface ◽  
Shape Identification ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Change Material

Experimental Validation of Numerical Predictions for the Transient Performance of a Simple Latent Heat Storage Unit (LHSU) Utilizing Phase Change Material (PCM) and 3-D Printing

2017 ◽  
Author(s):  
Navin Kumar ◽  
Debjyoti Banerjee
Keyword(s):  
Phase Change ◽  
Experimental Validation ◽  
Numerical Models ◽  
Dominant Mode ◽  
Storage Unit ◽  
Latent Heat Storage ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Change Material ◽  
Melting And Solidification

Experimental validation was performed in this study to verify the efficacy of numerical models for predicting the location of solid-liquid interface in an axi-symmetric configuration during both melting and solidification in a Latent Heat Storage Unit (LHSU). Development of analytical solutions for predicting the location of the solid-liquid interface is often intractable in LHSU due to non-linear temperature distribution in the Phase Change Material (PCM). This is further complicated by the moving boundary problem with free convection within the liquid phase of the PCM. Analytical solutions available in the contemporary literature are based on simplified transient heat conduction models and often fail to reliably predict the charging and discharging time constants for LHSU with complex configurations. This study is designed with the goal of developing more sophisticated numerical models for the estimation of transient thermal performance of an LHSU with a simple configuration involving a shell and tube heat exchanger (HX). The LHSU utilized in this study is realized by integrating various types of Phase Change Materials (PCM) contained in the shell side of a HX. The LHSU is charged or discharged by pumping hot or cold fluids in the tube side of the HX (i.e., by pumping water at a fixed inlet temperature from a commercial chiller apparatus). This study enabled the characterization of the transient response of a LHSU subjected to conduction and forced convection heat transfer. The PCM used in this material was paraffin wax (PURETEMP 29). The HX in the LHSU consisted of a single pass straight tube (½ inch copper pipe) mounted within a single shell configuration. The shell was fabricated from plastic material using additive manufacturing (i.e., “3D Printing”). The temperature variation during melting and solidification of the PCM were measured at different radial and axial locations within the cylindrical shell that was mounted vertically. Temperature measurements were performed at different mass flowrate ranging from 0.004 Kg/sec to 0.007 Kg/sec for the same fluid temperature. The water bath temperatures were maintained at a constant temperature of 40°C for melting and 15°C for solidification. The experiment results show that the transient response of the LHSU for charging and discharging (i.e., time required for melting and solidification of the PCM) vary significantly. Comparison of the experimental data with analytical results (involving quasi-stationary models for phase change) demonstrate that natural convection is the dominant mode during the melting process, while conduction is the dominant mode during the solidification process.

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