scholarly journals Latent Heat Thermal Storage of Nano-Enhanced Phase Change Material Filled by Copper Foam with Linear Porosity Variation in Vertical Direction

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1508
Author(s):  
Mohammad Ghalambaz ◽  
Mohammad Shahabadi ◽  
S. A. M Mehryan ◽  
Mikhail Sheremet ◽  
Obai Younis ◽  
...  
Keyword(s):  
Natural Convection ◽  
Phase Change ◽  
Phase Change Material ◽  
Metal Foam ◽  
Vertical Direction ◽  
Melting Time ◽  
Copper Foam ◽  
Average Porosity ◽  
The Impact ◽  
Change Material

The melting flow and heat transfer of copper-oxide coconut oil in thermal energy storage filled with a nonlinear copper metal foam are addressed. The porosity of the copper foam changes linearly from bottom to top. The phase change material (PCM) is filled into the metal foam pores, which form a composite PCM. The natural convection effect is also taken into account. The effect of average porosity; porosity distribution; pore size density; the inclination angle of enclosure; and nanoparticles’ concentration on the isotherms, melting maps, and the melting rate are investigated. The results show that the average porosity is the most important parameter on the melting behavior. The variation in porosity from 0.825 to 0.9 changes the melting time by about 116%. The natural convection flows are weak in the metal foam, and hence, the impact of each of the other parameters on the melting time is insignificant (less than 5%).

scholarly journals Numerical Study of Latent Heat Thermal Energy Storage Enhancement by Nano-PCM in Aluminum Foam

Inventions ◽  
2018 ◽  
Vol 3 (4) ◽  
pp. 76 ◽  
Author(s):  
Bernardo Buonomo ◽  
Anna di Pasqua ◽  
Davide Ercole ◽  
Oronzio Manca
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Phase Change Material ◽  
Latent Heat ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Metal Foam ◽  
Storage System ◽  
Melting Time ◽  
Change Material

Thermal storage system (TES) with phase change material (PCM) is an important device to store thermal energy. It works as a thermal buffer to reconcile the supply energy with the energy demand. It has a wide application field, especially for solar thermal energy storage. The main drawback is the low value of thermal conductivity of the PCM making the system useless for thermal engineering applications. A way to resolve this problem is to combine the PCM with a highly conductive material like metal foam and/or nanoparticles. In this paper a numerical investigation on the metal foam effects in a latent heat thermal energy storage system, based on a phase change material with nanoparticles (nano-PCM), is accomplished. The modelled TES is a typical 70 L water tank filled with nano-PCM with pipes to transfer thermal energy from a fluid to the nano-PCM. The PCM is a pure paraffin wax and the nanoparticles are in aluminum oxide. The metal foam is made of aluminum with assigned values of porosity. The enthalpy-porosity theory is employed to simulate the phase change of the nano-PCM and the metal foam is modelled as a porous media. Numerical simulations are carried out using the Ansys Fluent code. The results are shown in terms of melting time, temperature at varying of time, and total amount of stored energy.

Investigation of enclosure aspect ratio effects on melting heat transfer characteristics of metal foam/phase change material composites

2019 ◽  
Vol 29 (9) ◽  
pp. 2994-3011
Author(s):  
Amin Samimi Behbahan ◽  
Aminreza Noghrehabadi ◽  
C.P. Wong ◽  
Ioan Pop ◽  
Morteza Behbahani-Nejad
Keyword(s):  
Heat Transfer ◽  
Aspect Ratio ◽  
Phase Change ◽  
Phase Change Material ◽  
Metal Foam ◽  
Melting Time ◽  
Content Type ◽  
Aspect Ratios ◽  
Optimal Melting ◽  
Change Material

Purpose The purpose of this paper is to study thermal performance of metal foam/phase change materials composite under the influence of the enclosure aspect ratios (ratio of enclosure height: length). In this study, a compound metal foam/phase change material (PCM), which has been proved to be one of the most promising approaches for thermal conductivity promotion on PCMs, was used. Design/methodology/approach The PCM is considered initially at its melting temperature. The enclosure for all the cases has a constant volume with various aspect ratios. The left side of the enclosure is suddenly exposed to a thermal source having a constant heat flux, while the other three surfaces are kept thermally insulated. A two-dimensional numerical model considering the non-equilibrium thermal factor, non-Darcy effect and local natural convection was proposed. The coupling between velocity and pressure is solved using the SIMPLEC, and the Rhie and Chow interpolation is used to avoid the checker-board solutions for the pressure. Findings The effects of foam porosity and aspect ratio of the enclosure on the PCM’s melting time were investigated. The results indicated that enclosure aspect ratio plays a fundamental role in phase change of copper foam/PCM composites. For higher porosities, enclosures with bigger aspect ratios proved to led to optimal melting time. Besides, the best enclosure aspect ratio and foam porosity for a fixed-volume enclosure to have the shortest melting time are 2.1 and 91.66 per cent, respectively. However, for a specific amount of PCM inside a variable volume enclosure, the optimal melting time was for foam with ε = 95 per cent. The achieved results prove the great importance of selection of aspect ratio to benefit both conduction and convection heat transfer simultaneously. Originality/value The area of energy storage systems is original.

Melting of a Phase Change Material Filled in a Metal Foam: A Visualized Study at the Pore-Scale Using Infrared Imaging

2016 ◽  
Author(s):  
Hong-Qing Jin ◽  
Li-Wu Fan
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Thermal Imaging ◽  
Metal Foam ◽  
Temperature Measurements ◽  
Paraffin Wax ◽  
Pore Scale ◽  
Ir Camera ◽  
Copper Foam ◽  
Change Material

The thermal imaging technique was applied in this work to measure the transient temperature fields during melting of a phase change material (PCM) in a metal foam. A paraffin wax was used as the PCM that was filled in an open-celled copper foam. Melting of a paraffin wax in the presence of copper foam was studied in a rectangular cavity that was heated from one lateral side wall, while the top surface was exposed to an infrared (IR) camera. A thermocouple (TC) was also employed to validate the accuracy of temperature measurements by IR thermal imaging. The relative deviation of measured temperature by the TC and IR camera was found to be under 2% in steady state and under 4% during the entire course of melting. The resolution of IR thermal imaging with the aid of a macro lens allowed for temperature measurements at pore-scale of the copper foam. Local thermal imaging was captured through a minor window on the top plate of the container. Three points (Sp1–3) inside a selected individual pore were marked to quantify the temperature variations of melting process within metal foam/PCM at pore-scale. The average temperature differences between Sp1 and Sp2, Sp3 were found to be about 1 °C over the entire course of melting, and the maximum value was up to nearly 10 °C around the melting point. These preliminary results clearly highlighted the effect of metal ligaments on the temperature distributions at pore-scale.

Thermal Energy Storage Through Melting of a Commercial Phase Change Material in an Annulus with Radially Divergent Longitudinal Fins

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Tonny Tabassum Mainul Hasan ◽  
Latifa Begum
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Phase Change Material ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Storage System ◽  
Operating Conditions ◽  
Melting Time ◽  
Bottom Part ◽  
Change Material

This study reports on the unsteady two-dimensional numerical investigations of melting of a paraffin wax (phase change material, PCM) which melts over a temperature range of 8.7oC. The PCM is placed inside a circular concentric horizontal-finned annulus for the storage of thermal energy. The inner tube is fitted with three radially diverging longitudinal fins strategically placed near the bottom part of the annulus to accelerate the melting process there. The developed CFD code used in Tabassum et al., 2018 is extended to incorporate the presence of fins. The numerical results show that the average Nusselt number over the inner tube surface, the total melt fraction, the total stored energy all increased at every time instant in the finned annulus compared to the annulus without fins. This is due to the fact that in the finned annulus, the fins at the lower part of the annulus promotes buoyancy-driven convection as opposed to the slow conduction melting that prevails at the bottom part of the plain annulus. Fins with two different heights have been considered. It is found that by extending the height of the fin to 50% of the annular gap about 33.05% more energy could be stored compared to the bare annulus at the melting time of 82.37 min for the identical operating conditions. The effects of fins with different heights on the temperature and streamfunction distributions are found to be different. The present study can provide some useful guidelines for achieving a better thermal energy storage system.

scholarly journals Numerical Simulation of the Impact of the Heat Source Position on Melting of a Nano-Enhanced Phase Change Material

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1425
Author(s):  
Tarek Bouzennada ◽  
Farid Mechighel ◽  
Kaouther Ghachem ◽  
Lioua Kolsi
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Phase Change Material ◽  
Numerical Study ◽  
Melting Rate ◽  
Heat Transfer Fluid ◽  
Commercial Code ◽  
Tube Position ◽  
The Impact ◽  
Change Material

A 2D-symmetric numerical study of a new design of Nano-Enhanced Phase change material (NEPCM)-filled enclosure is presented in this paper. The enclosure is equipped with an inner tube allowing the circulation of the heat transfer fluid (HTF); n-Octadecane is chosen as phase change material (PCM). Comsol-Multiphysics commercial code was used to solve the governing equations. This study has been performed to examine the heat distribution and melting rate under the influence of the inner-tube position and the concentration of the nanoparticles dispersed in the PCM. The inner tube was located at three different vertical positions and the nanoparticle concentration was varied from 0 to 0.06. The results revealed that both heat transfer/melting rates are improved when the inner tube is located at the bottom region of the enclosure and by increasing the concentration of the nanoparticles. The addition of the nanoparticles enhances the heat transfer due to the considerable increase in conductivity. On the other hand, by placing the tube in the bottom area of the enclosure, the liquid PCM gets a wider space, allowing the intensification of the natural convection.

scholarly journals Discharge of a composite metal foam/phase change material to air heat exchanger for a domestic thermal storage unit

2020 ◽  
Vol 148 ◽  
pp. 987-1001 ◽  
Author(s):  
Pouyan Talebizadeh Sardari ◽  
Donald Giddings ◽  
David Grant ◽  
Mark Gillott ◽  
Gavin S. Walker
Keyword(s):  
Heat Exchanger ◽  
Phase Change ◽  
Phase Change Material ◽  
Metal Foam ◽  
Thermal Storage ◽  
Storage Unit ◽  
Change Material

STUDY ON SOLIDIFICATION OF PHASE CHANGE MATERIAL IN FRACTAL POROUS METAL FOAM

Fractals ◽  
2015 ◽  
Vol 23 (01) ◽  
pp. 1540003 ◽  
Author(s):  
CHENGBIN ZHANG ◽  
LIANGYU WU ◽  
YONGPING CHEN
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Pore Structure ◽  
Phase Change Material ◽  
Fractal Structure ◽  
Metal Foam ◽  
Porous Metal ◽  
Solid Matrix ◽  
Transfer Model ◽  
Change Material

The Sierpinski fractal is introduced to construct the porous metal foam. Based on this fractal description, an unsteady heat transfer model accompanied with solidification phase change in fractal porous metal foam embedded with phase change material (PCM) is developed and numerically analyzed. The heat transfer processes associated with solidification of PCM embedded in fractal structure is investigated and compared with that in single-pore structure. The results indicate that, for the solidification of phase change material in fractal porous metal foam, the PCM is dispersedly distributed in metal foam and the existence of porous metal matrix provides a fast heat flow channel both horizontally and vertically, which induces the enhancement of interstitial heat transfer between the solid matrix and PCM. The solidification performance of the PCM, which is represented by liquid fraction and solidification time, in fractal structure is superior to that in single-pore structure.

Numerical Solution of Melting Processes for Fixed and Unfixed Phase Change Material in the Presence of Magnetic Field: Simulation of Low Gravity Environment

2001 ◽  
Author(s):  
Y. Asako ◽  
E. Gonçalves ◽  
M. Faghri ◽  
M. Charmchi
Keyword(s):  
Magnetic Field ◽  
Natural Convection ◽  
Phase Change ◽  
Phase Change Material ◽  
Flow Patterns ◽  
Transport Processes ◽  
Low Gravity ◽  
Horizontal Magnetic Field ◽  
Wall Heating ◽  
Change Material

Abstract Transport processes associated with melting of an electrically conducting Phase Change Material (PCM), placed inside a rectangular enclosure, under low-gravity environment, and in the presence of a magnetic field is simulated numerically. Electromagnetic forces damp the natural convection as well as the flow induced by sedimentation and/or floatation, and thereby simulating the low gravity environment of outer space. Computational experiments are conducted for both side-wall heating and top-wall heating under horizontal magnetic field. The governing equations are discretized using a control-volume-based finite difference scheme. Numerical solutions are obtained for true low-gravity environment as well as for the simulated-low-gravity conditions resulted by the presence of a horizontal magnetic field. The effects of magnetic field on the natural convection, solid phase floatation/sedimentation, liquid-solid interface location, solid melting rate, and flow patterns are investigated. It is found that the melting under low-gravity environment can reasonably be simulated on earth via applying a strong horizontal magnetic field. However, the flow patterns obtained for the true low-gravity cases are not similar to the corresponding cases solved for the simulated-low-gravity environment.

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