scholarly journals Observation the melting process of the phase change material inside a half-cylindrical with thermal non-equilibrium porous media: CFD simulation

2021 ◽  
pp. 101496
Author(s):  
Yan Cao ◽  
Hamdaui Ayed ◽  
Hussein Togun ◽  
Hajar Alias ◽  
Souhail Mohamed Bouzgarrou ◽  
...  
Keyword(s):  
Porous Media ◽  
Phase Change ◽  
Phase Change Material ◽  
Cfd Simulation ◽  
Melting Process ◽  
Change Material ◽  
Non Equilibrium

scholarly journals Melting process modeling of Carreau non-Newtonian phase- change material in dual porous vertical concentric cylinders

2020 ◽  
pp. 329-329
Author(s):  
Mohsen Talebzadegan ◽  
Mojtaba Moravej ◽  
Ehsanolah Assareh ◽  
Mohsen Izadi
Keyword(s):  
Porous Media ◽  
Rayleigh Number ◽  
Phase Change ◽  
Phase Change Material ◽  
Melting Process ◽  
Darcy Number ◽  
Melting Time ◽  
Stefan Number ◽  
Concentric Cylinders ◽  
Change Material

In this paper a numerical simulation of the melting process of Carreau non- Newtonian phase-change material (PCM) inside two porous vertical concentric cylinders included constant temperatures of the inner and outer walls, represented by Th and Tc respectively. Half of the void between the two pipes is filled with copper porous media and paraffin wax as a phase change material. The governing equations are converted into a dimentionless form and are solved using the finite element method. The enthalpy- porosity theory is applied to simulate the phase change of PCM while the porous media follow to the Darcy law. Outcomes are shown and compared in terms of the streamline, isotherm, melting fraction and mean Nusselt numbers. The solid- liquid interface location and the temperature distribution are predicted to describe the melting process. The effects of the Carreau index, porosity and non-dimensional parameters such as Stefan number, Darcy number and Rayleigh number are analyzed. Our results indicate a good agreement between this study and the previous investigations. The results show that an increase in Rayleigh number, Stefan number and Darcy number increases the melting volume fraction and reduces the melting time. Also, the time of melting non-Newtonian phase change material decreases when Carreau index and porosity decrease.

scholarly journals Dynamics of Melting Process in Phase Change Material Windows Determined Based on Direct Light Transmission

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 721
Author(s):  
Dariusz Heim ◽  
Michał Krempski-Smejda ◽  
Pablo Roberto Dellicompagni ◽  
Dominika Knera ◽  
Anna Wieprzkowicz ◽  
...  
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Light Transmission ◽  
Melting Process ◽  
Refraction Index ◽  
Light Transmittance ◽  
Reference Case ◽  
Solar Radiation Intensity ◽  
Direct Light ◽  
Change Material

Detailed analyses of melting processes in phase change material (PCM) glazing units, changes of direct transmittance as well as investigation of refraction index were provided based on laboratory measurements. The main goal of the study was to determine the direct light transmittance versus time under constant solar radiation intensity and stable temperature of the surrounding air. The experiment was conducted on a triple glazed unit with one cavity filled with a paraffin RT21HC as a PCM. The unit was installed in a special holder and exposed to the radiation from an artificial sun. The vertical illuminance was measured by luxmeters and compared with a reference case to determine the direct light transmittance. The transmittance was determined for the whole period of measurements when some specific artefacts were identified and theoretically explained based on values of refractive indexes for paraffins in the solid and liquid state, and for a glass. The melting process of a PCM in a glass unit was identified as a complex one, with interreflections and refraction of light on semi layers characterized by a different physical states (solid, liquid or mushy). These optical phenomena caused nonuniformity in light transmittance, especially when the PCM is in a mushy state. It was revealed that light transmittance versus temperature cannot be treated as a linear function.

Investigation on the melting process of phase change material in a square cavity with a single fin attached at the center of the heated wall

2018 ◽  
Vol 83 (1) ◽  
pp. 10902 ◽  
Author(s):  
Müslüm Arıcı ◽  
Ensar Tütüncü ◽  
Hasan Karabay ◽  
Antonio Campo
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Melting Process ◽  
Melting Rate ◽  
Paraffin Wax ◽  
Heated Wall ◽  
Dual Function ◽  
Square Cavity ◽  
Change Material ◽  
Fin Length

In this study, melting of a phase change material (PCM) in a square cavity with a single fin attached at the center of the heated wall is studied numerically employing the enthalpy-porosity method. The opposite wall to the heated wall in the square cavity is cold. The other two adjacent walls are thermally insulated. Paraffin wax is chosen as a PCM due to its demonstrable favorable properties. The thermophysical properties of the paraffin wax are assumed to be a dual function of temperature and phase. The influence of the fin length on the melting process of the paraffin wax is examined. Moreover, the orientation of the square cavity on the melting process is scrutinized. The numerical results elucidate that the melting rates increase significantly by embedding the fin into the paraffin wax. As the fin length is incremented, the melting rate intensifies considerably during the early stages of melting. However, the effect of the fin length on the melting rate diminishes after a long period of heating has happened. It is also observed that the melting rate can be augmented significantly by changing the orientation of the heated wall in the square cavity.

Thermodynamic Optimization of Phase-Change Energy Storage Using Two or More Materials

1992 ◽  
Vol 114 (1) ◽  
pp. 84-90 ◽  
Author(s):  
J. S. Lim ◽  
A. Bejan ◽  
J. H. Kim
Keyword(s):  
Energy Storage ◽  
Melting Point ◽  
Phase Change ◽  
Phase Change Material ◽  
Finite Thickness ◽  
Melting Process ◽  
Two Phase ◽  
In Series ◽  
Optimal Melting ◽  
Change Material

This paper documents the relative merits of using more than one type of phase-change material for energy storage. In the case of two phase-change systems in series, which are melted by the same stream of hot fluid, there exists an optimal melting point for each of the two materials. The first (upstream) system has the higher of the two melting points. The second part of the paper addresses the theoretical limit in which the melting point can vary continuously along the source stream, i.e., when an infinite number of different (and small) phase-change systems are being heated in series. It is shown that the performance of this scheme is equivalent to that which uses an optimum single phase-change material, in which the hot stream remains unmixed during the melting process. The time dependence, finite thickness and longitudinal variation of the melt layer caused by an unmixed stream are considered in the third part of the paper. It is shown that these features have a negligible effect on the optimal melting temperature, which is slightly higher than (T∞Te)1/2.

scholarly journals Numerical investigation on the phase change process of different shaped macro encapsulated PCM

2018 ◽  
Vol 7 (4.5) ◽  
pp. 587
Author(s):  
Jay R. Patel ◽  
Manish K. Rathod
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Phase Change Material ◽  
Melting Process ◽  
Complex Flow ◽  
Ansys Fluent ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Convection Dominated ◽  
Change Material

Latent heat energy storage using macro encapsulated phase change material is an emerging technique for thermal energy storage applica- tions. The main aim of the present investigation is to investigate the melting process of phase change material filled in different shaped configurations. The selected different cavities are square, circular and triangular. A mathematical model based on convection dominated melting is required to be developed, especially in view of the complex flow geometries encountered in such problems. Thus, an attempt has been made to develop a model using ANSYS Fluent 16.2 to investigate the heat transfer rate and solid-liquid interface visualization of PCM filled in different shapes of cavity. It is found that triangular shaped macro encapsulated PCM melts faster than square and circu- lar shaped encapsulated PCM.   

scholarly journals Experimental evaluation of phase change material in radiant cooling panels integrated with thermoelectric modules

2019 ◽  
Vol 111 ◽  
pp. 01002
Author(s):  
Yong-Kwon Kang ◽  
Beom-Jun Kim ◽  
Soo-Yeol Yoon ◽  
Jae-Weon Jeong
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Thermal Energy ◽  
Phase Change Materials ◽  
Target Surface ◽  
Melting Process ◽  
Night Time ◽  
Thermoelectric Modules ◽  
Radiant Cooling ◽  
Change Material

This study proposes a phase change material for use in radiant cooling panels integrated with thermoelectric modules (PCM–TERCP) and evaluates its performance characteristics during the solidification and melting process of phase change materials in design conditions. The PCM–TERCP consists of phase change materials (PCMs), thermoelectric modules (TEMs), and aluminumpanels. TEMs operate to freeze the PCM, and PCM stores the cooling thermal energy to maintain the constant surface temperature of the panel for radiant cooling. The main purpose of thermal energy storage systems is the shift of the electricity consumption from day-time to night-time during the summer season. Therefore, PCM–TERCP can implement off-peak operation according to which energy is expected to be saved. The melting temperature of PCM and the target surface temperatures of the bottom panels of PCM–TERCP were designed to be 16°C. Additionally, the room temperature and mean radiant temperature (MRT) was set to 24°C, while the thickness of the PCM pouch was 10 mm. As a result, the solidification process required 4 h and the total input power was 0.528 kWh. Correspondingly, the melting process can operate passively over a period of 4 h. In most cases, the operating temperature was lower than 19°C, which validates the temperature response of PCM–TERCP.

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