scholarly journals Preparation of Stable Phase Change Material Emulsions for Thermal Energy Storage and Thermal Management Applications: A Review

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 121
Author(s):  
Liu Liu ◽  
Jianlei Niu ◽  
Jian-Yong Wu
Keyword(s):  
Heat Transfer ◽  
Energy Storage ◽  
Phase Change ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Storage Capacity ◽  
Heat Storage ◽  
Thermal Storage ◽  
Stable Phase ◽  
Storage Media

Thermal energy storage (TES) is an important means for the conservation and efficient utilization of excessive and renewable energy. With a much higher thermal storage capacity, latent heat storage (LHS) may be more efficient than sensible heat storage. Phase change materials (PCMs) are the essential storage media for LHS. PCM emulsions have been developed for LHS in flow systems, which act as both heat transfer and thermal storage media with enhanced heat transfer, low pumping power, and high thermal storage capacity. However, two major barriers to the application of PCM emulsions are their instability and high degree of supercooling. To overcome these, various strategies have been attempted, such as the reduction of emulsion droplet size, addition of nucleating agents, and optimization of the formulation. To the best of our knowledge, however, there is still a lack of review articles on fabrication methods for PCM emulsions or their latest applications. This review was to provide an up-to-date and comprehensive summary on the effective strategies and the underlying mechanisms for the preparation of stable PCM emulsions and reduction of supercooling, especially with the organic PCMs of paraffin. It was also to share our insightful perspectives on further development and potential applications of PCM emulsions for efficient energy storage.

Experimental Study and Numerical Simulation on Thermal Energy Storage Characteristics of Composite Phase Change Materials in Annular Space of Vertical Double-Pipe Heat Exchanger

2014 ◽  
Vol 1053 ◽  
pp. 143-149 ◽  
Author(s):  
Xiao Hong Liu ◽  
Zi Ye Ling ◽  
Peng Sun ◽  
Xiao Ming Fang ◽  
Tao Xu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Energy Storage ◽  
Phase Change ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Phase Change Materials ◽  
Thermal Storage ◽  
Annular Space ◽  
Double Pipe ◽  
Storage Characteristics

Experimental system on thermal energy storage characteristics of phase change materials (PCMs) in annular space of a vertical double-pipe heat exchanger was set up. The thermal storage performance of paraffin and paraffin/expanded graphite composite PCM with the mass fraction of 70% paraffin was compared. The Fluent software was used to simulate the temperature field of the composite PCM during the thermal storage process. The results show that, for the paraffin, in the sensible heat storage phase, because the heat transfer process is controlled by the heat conduction, the temperature in paraffin gradually reduces from the inside to the outside of the annular space. But for the phase change thermal storage phase, solid-liquid phase change heat transfer is controlled by natural convection and the effect of buoyancy, the temperature in paraffin reduces from top to bottom, from the inside to the outside of the annular space. For the composite PCM, heat transfer is controlled only by the heat conduction process, both the sensible and latent heat storage process, the temperature in the composite PCM decreases from bottom to top, from inside to outside of the annular space. As the thermal conductivity of composite PCM is 15.65 times of paraffin, the thermal energy storage time is shortened by 86.6% than paraffin. The temperature fields of composite PCM in different time are obtained by numerical simulation method, the measured temperatures and simulation results are in good agreement.

scholarly journals Using the Analytic Hierarchy Process to Prioritize and Select Phase Change Materials for Comfort Application in Buildings

2014 ◽  
Vol 10 (1) ◽  
pp. 21-28 ◽  
Author(s):  
Lavinia Gabriela Socaciu ◽  
Paula Veronica Unguresan
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Phase Change Materials ◽  
Storage Capacity ◽  
Heat Storage ◽  
Analytic Hierarchy ◽  
Energy Storage Capacity ◽  
Hierarchy Process

Abstract Phase change materials (PCMs) selection and prioritization for comfort application in buildings have a significant contribution to the improvement of latent heat storage systems. PCMs have a relatively large thermal energy storage capacity in a temperature range close to their switch point. PCMs absorb energy during the heating process as phase change takes place and release energy to the environment in the phase change range during a reverse cooling process. Thermal energy storage systems using PCMs as storage medium offer advantages such as: high heat storage capacity and store/release thermal energy at a nearly constant temperature, relative low weight, small unit size and isothermal behaviour during charging and discharging when compared to the sensible thermal energy storage. PCMs are valuable only in the range of temperature close to their phase change point, since their main thermal energy storage capacity depend on their mass and on their latent heat of fusion. Selection of the proper PCMs is a challenging task because there are lots of different materials with different characteristics. In this research paper the principles and techniques of the Analytic Hierarchy Process (AHP) are presented, discussed and applied in order to prioritize and select the proper PCMs for comfort application in buildings. The AHP method is used for solving complex decisional problems and allows the decision maker to take the most suitable decisions for the problem studied. The results obtained reveal that the AHP method can be successfully applied when we want to choose a PCM for comfort application in buildings.

scholarly journals Thermal energy storage and thermal conductivity properties of fatty acid/fatty acid-grafted-CNTs and fatty acid/CNTs as novel composite phase change materials

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Amir Al-Ahmed ◽  
Ahmet Sarı ◽  
Mohammad Abu Jafar Mazumder ◽  
Billel Salhi ◽  
Gökhan Hekimoğlu ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Fatty Acid ◽  
Energy Storage ◽  
Phase Change ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Phase Change Materials ◽  
Storage Capacity ◽  
Heat Storage ◽  
Transfer Property

Abstract In recent year, fatty acids (FAs) are heavily studied for heat storage applications and they have shown promising advantages over other organic phase change materials (PCMs). Among the FAs; capric, palmitic and stearic acids are the most studied PCMs. Several researchers have investigated these FAs and tried to improve their thermal properties, mainly by adding different high conducting fillers, such as graphite, metal foams, CNTs, graphene etc. In most cases, these fillers improved the thermal conductivity and heat transfer property but reduce the heat storage capacity considerably. These composites also lose the mixing uniformity during the charging and discharging process. To overcome these issues, selected FAs were grafted on the functionalized CNT surfaces and used as conductive fillers to prepare FA based composite PCMs. This process significantly contributed to prevent the drastic reduction of the overall heat storage capacity and also showed better dispersion in both solid and liquid state. Thermal cycling test showed the variations in the thermal energy storage values of all composite PCMs, however, within the tolerable grade and they had appreciable phase change stability and good chemical stability even after 2,000 cycles.

scholarly journals Latent Heat Phase Change Heat Transfer of a Nanoliquid with Nano–Encapsulated Phase Change Materials in a Wavy-Wall Enclosure with an Active Rotating Cylinder

2021 ◽  
Vol 13 (5) ◽  
pp. 2590
Author(s):  
S. A. M. Mehryan ◽  
Kaamran Raahemifar ◽  
Leila Sasani Gargari ◽  
Ahmad Hajjar ◽  
Mohamad El Kadri ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Energy Storage ◽  
Phase Change ◽  
Latent Heat ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Wavy Wall ◽  
Governing Equations ◽  
Stefan Number ◽  
Change Material

A Nano-Encapsulated Phase-Change Material (NEPCM) suspension is made of nanoparticles containing a Phase Change Material in their core and dispersed in a fluid. These particles can contribute to thermal energy storage and heat transfer by their latent heat of phase change as moving with the host fluid. Thus, such novel nanoliquids are promising for applications in waste heat recovery and thermal energy storage systems. In the present research, the mixed convection of NEPCM suspensions was addressed in a wavy wall cavity containing a rotating solid cylinder. As the nanoparticles move with the liquid, they undergo a phase change and transfer the latent heat. The phase change of nanoparticles was considered as temperature-dependent heat capacity. The governing equations of mass, momentum, and energy conservation were presented as partial differential equations. Then, the governing equations were converted to a non-dimensional form to generalize the solution, and solved by the finite element method. The influence of control parameters such as volume concentration of nanoparticles, fusion temperature of nanoparticles, Stefan number, wall undulations number, and as well as the cylinder size, angular rotation, and thermal conductivities was addressed on the heat transfer in the enclosure. The wall undulation number induces a remarkable change in the Nusselt number. There are optimum fusion temperatures for nanoparticles, which could maximize the heat transfer rate. The increase of the latent heat of nanoparticles (a decline of Stefan number) boosts the heat transfer advantage of employing the phase change particles.

scholarly journals Special Issue “Advanced Phase Change Materials for Thermal Storage”

2021 ◽  
Vol 11 (4) ◽  
pp. 1390
Author(s):  
Rocío Bayón
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Phase Change Materials ◽  
Thermal Storage ◽  
Research Topic ◽  
Special Issue ◽  
Advanced Phase

Thermal energy storage using phase change materials (PCMs) is a research topic that has attracted much attention in recent decades [...]

scholarly journals Experimental and Computational Investigations of Phase Change Thermal Energy Storage Canisters

2000 ◽  
Vol 122 (4) ◽  
pp. 176-182 ◽  
Author(s):  
Mounir Ibrahim ◽  
Pavel Sokolov ◽  
Thomas Kerslake ◽  
Carol Tolbert
Keyword(s):  
Heat Transfer ◽  
Energy Storage ◽  
Phase Change ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Radiation Heat Transfer ◽  
Convection Heat Transfer ◽  
Melting Time ◽  
Radiation Heat ◽  
Space Experiments

Two sets of experimental data for cylindrical canisters with thermal energy storage applications were examined in this paper: 1) Ground Experiments and 2) Space Experiments. A 2-D computational model was developed for unsteady heat transfer (conduction and radiation) with phase-change. The radiation heat transfer employed a finite volume method. The following was found in this study: 1) Ground Experiments, the convection heat transfer is equally important to that of the radiation heat transfer; Radiation heat transfer in the liquid is found to be more significant than that in the void; Including the radiation heat transfer in the liquid resulted in lower temperatures (about 15 K) and increased the melting time (about 10 min.); Generally, most of the heat flow takes place in the radial direction. 2) Space Experiments, Radiation heat transfer in the void is found to be more significant than that in the liquid (exactly the opposite to the Ground Experiments); Accordingly, the location and size of the void affects the performance considerably; Including the radiation heat transfer in the void resulted in lower temperatures (about 40 K). [S0199-6231(00)00304-X]

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