Super-Cooling Suppression of Microencapsulated PCM

Microencapsulated Phase change material can absorb and release large amounts of latent heat over a defined temperature range as its physical state changes. The microencapsulated PCM has high energy density and isothermal behavior during charging and discharging and can avoid the contradiction of the energy supply and demand unbalance in time and space. Meanwhile, the shell can separate the phase change material from the outside environment in order to protect the core material. But the super-cooling problem is a main barrier for microencapsulated PCM application. So this paper talks about how to dealing with super-cooling based on related literatures and gives an overview about the methodology in this area.

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Comparison of Stratification in a Water Tank and a PCM-Water Tank

ASME 2007 Energy Sustainability Conference ◽

10.1115/es2007-36074 ◽

2007 ◽

Cited By ~ 2

Author(s):

A. Castell ◽

C. Sole´ ◽

M. Medrano ◽

M. Nogue´s ◽

L. F. Cabeza

Keyword(s):

Phase Change ◽

Phase Change Material ◽

Temperature Change ◽

High Energy ◽

Hot Water ◽

The Other ◽

High Energy Density ◽

Water Tank ◽

Charging And Discharging Processes ◽

Change Material

Most of the storage systems available on the market use water as storage medium. Enhancing the storage performance is necessary to increase the performance of most systems. The stratification phenomenon is employed to improve the efficiency of storage tanks. Heat at an intermediate temperature, not high enough to heat up the top layer, can still be used to heat the lower, colder layers. There are a lot of parameters to study the stratification in a water tank such as the Mix Number and the Richardson Number among others. The idea studied here was to use these stratification parameters to compare two tanks with the same dimensions during charging and discharging processes. One of them is a traditional water tank and the other is a PCM-water (a water tank with a Phase Change Material). A PCM is good because it has high energy density if there is a small temperature change, since then the latent heat is much larger than the sensible heat. On the other hand, the temperature change in the top layer of a hot water store with stratification is usually small as it is held as close as possible at or above the temperature for usage. In the system studied the Phase Change Material is placed at the top of the tank, therefore the advantages of the stratification still remain. The aim of this work is to demonstrate that the use of PCM in the upper part of a water tank holds or improves the benefit of the stratification phenomenon.

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Thermal Characterization of a Heat Management Module Containing Microencapsulated Phase Change Material

Energies ◽

10.3390/en12112164 ◽

2019 ◽

Vol 12 (11) ◽

pp. 2164

Author(s):

H.M. Shih ◽

Yi-Pin Lin ◽

L.P. Lin ◽

Chi-Ming Lai

Keyword(s):

Phase Change ◽

Phase Change Material ◽

Wall Temperature ◽

Heat Dissipation ◽

Thermal Protection ◽

Core Material ◽

Heat Management ◽

Microencapsulated Phase Change Material ◽

Aluminum Honeycomb ◽

Change Material

In this study, a heat management module containing a microencapsulated phase change material (mPCM) was fabricated from mPCM (core material: paraffin; melting temperature: 37 °C) and aluminum honeycomb structures (8 mm core cell). The aluminum honeycomb functioned both as structural support and as a heat transfer channel. The thermal management performance of the proposed module under constant-temperature boundary conditions was investigated experimentally. The thermal protection period of the module decreased as the Stefan number increased; however, increasing the subcooling factor could effectively enhance the thermal protection performance. When the cold-wall temperature TC was fixed at 17 °C and the initial hot wall temperature was 47–67 °C, the heat dissipation of the module was complete 140 min after the hot-wall heat supply was stopped. The time required to complete the heat dissipation increased to 280 min when TC increased to 27 °C.

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Optimization of Phase-Change Material–Elastomer Composite and Integration in Kirigami-Inspired Voxel-Based Actuators

Frontiers in Robotics and AI ◽

10.3389/frobt.2021.672934 ◽

2021 ◽

Vol 8 ◽

Author(s):

Gilles Decroly ◽

Romain Raffoul ◽

Clara Deslypere ◽

Paul Leroy ◽

Louis Van Hove ◽

...

Keyword(s):

Phase Change ◽

Phase Change Material ◽

Close Contact ◽

Low Cost ◽

High Energy ◽

Design Approach ◽

High Energy Density ◽

Complex Tasks ◽

Change Material ◽

Actuation Strain

Phase-change material–elastomer composite (PCMEC) actuators are composed of a soft elastomer matrix embedding a phase-change fluid, typically ethanol, in microbubbles. When increasing the temperature, the phase change in each bubble induces a macroscopic expansion of the matrix. This class of actuators is promising for soft robotic applications because of their high energy density and actuation strain, and their low cost and easy manufacturing. However, several limitations must be addressed, such as the high actuation temperature and slow actuation speed. Moreover, the lack of a consistent design approach limits the possibility to build PCMEC-based soft robots able to achieve complex tasks. In this work, a new approach to manufacture PCMEC actuators with different fluid–elastomer combinations without altering the quality of the samples is proposed. The influence of the phase-change fluid and the elastomer on free elongation and bending is investigated. We demonstrate that choosing an appropriate fluid increases the actuation strain and speed, and decreases the actuation temperature compared with ethanol, allowing PCMECs to be used in close contact with the human body. Similarly, by using different elastomer materials, the actuator stiffness can be modified, and the experimental results showed that the curvature is roughly proportional to the inverse of Young’s modulus of the pure matrix. To demonstrate the potential of the optimized PCMECs, a kirigami-inspired voxel-based design approach is proposed. PCMEC cubes are molded and reinforced externally by paper. Cuts in the paper induce anisotropy into the structure. Elementary voxels deforming according to the basic kinematics (bending, torsion, elongation, compression and shear) are presented. The combination of these voxels into modular and reconfigurable structures could open new possibilities towards the design of flexible robots able to perform complex tasks.

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A Novel Approach on the Advancement in Polymer Phase Change Material in Solar Energy

International Journal of Photoenergy ◽

10.1155/2022/3519517 ◽

2022 ◽

Vol 2022 ◽

pp. 1-8

Author(s):

G. Jegan ◽

P. Ramani ◽

T. J. Nagalakshmi ◽

S. Chitra ◽

T. Samraj Lawrence

Keyword(s):

Solar Energy ◽

Phase Change ◽

Phase Change Material ◽

High Energy ◽

High Energy Density ◽

Energy Output ◽

Polymer Phase ◽

Diverse Range ◽

Novel Approach ◽

Change Material

A wide interest has been shown in the application of solar energy in recent times. This motivated the researchers to make a development in the approach of solar energy, but there are different technologies like MPPT, CPG, and grid mode that have been used to maintain a constant temperature. Among these, phase change material has been used to regulate the temperature in the system. Solar energy is becoming an essential approach for increasing the efficiency of thermal energy conversion and utilizing polymeric step change composites, which have attracted extremely large interest in recent years due to their advantages of high energy density and powerful energy output stability. A plethora of reviews and reports have been published to compile the diverse range of PCMs made available for various applications. PCMs are created by improving thermophysical thermodynamic stability, latent heat, and heat capacity. Furthermore, the possible applications of polymer phase PCMs in a variety of fields, such as energy storage devices, thermal corrective action, and temperature-controlled drug carriers, are detailed. In this paper, a novel approach on the advancement of nanoconfined phase change material is defined along with the application of the solar energy system.

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Synthesis and Characterization of Microencapsulated Phase Change Material of Magnesium Sulfate Heptahydrate/Urea Resin via Emulsion Polymerization Method

Volume 2: Micro/Nano-Thermal Manufacturing and Materials Processing; Boiling, Quenching and Condensation Heat Transfer on Engineered Surfaces; Computational Methods in Micro/Nanoscale Transport; Heat and Mass Transfer in Small Scale; Micro/Miniature Multi-Phase Devices; Biomedical Applications of Micro/Nanoscale Transport; Measurement Techniques and Thermophysical Properties in Micro/Nanoscale; Posters ◽

10.1115/mnhmt2016-6344 ◽

2016 ◽

Author(s):

Chenzhen Liu ◽

Ling Ma ◽

Zhonghao Rao ◽

Yimin Li

Keyword(s):

Particle Size ◽

Phase Change ◽

Magnesium Sulfate ◽

Emulsion Polymerization ◽

Phase Change Material ◽

Core Material ◽

Sulfate Heptahydrate ◽

Microencapsulated Phase Change Material ◽

Change Material ◽

Polymerization Method

In this study, Microencapsulated phase change material (MicroPCM) was successfully synthesized by emulsion polymerization method, using magnesium sulfate heptahydrate (MSH) as core material and urea resin (UR) as shell material. The surface morphology of the MicroPCM was tested by scanning electron microscopy (SEM) and optical microscope (OM). The thermal property and particle size were investigated by differential scanning calorimetry (DSC) and laser particle size analyzer (LPA), respectively. The chemical structure of microcapsule was analyzed by Fourier-transform infrared spectroscopy (FTIR).

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Optimized Modeling and Design of a PCM-Enhanced H2 Storage

Energies ◽

10.3390/en14061554 ◽

2021 ◽

Vol 14 (6) ◽

pp. 1554

Author(s):

Andrea Luigi Facci ◽

Marco Lauricella ◽

Sauro Succi ◽

Vittorio Villani ◽

Giacomo Falcucci

Keyword(s):

Energy Storage ◽

Phase Change ◽

Phase Change Material ◽

Power Density ◽

Latent Heat ◽

Metal Hydride ◽

Renewable Energy Sources ◽

High Energy ◽

High Energy Density ◽

Change Material

Thermal and mechanical energy storage is pivotal for the effective exploitation of renewable energy sources, thus fostering the transition to a sustainable economy. Hydrogen-based systems are among the most promising solutions for electrical energy storage. However, several technical and economic barriers (e.g., high costs, low energy and power density, advanced material requirements) still hinder the diffusion of such solutions. Similarly, the realization of latent heat storages through phase change materials is particularly attractive because it provides high energy density in addition to allowing for the storage of the heat of fusion at a (nearly) constant temperature. In this paper, we posit the challenge to couple a metal hydride H2 canister with a latent heat storage, in order to improve the overall power density and realize a passive control of the system temperature. A highly flexible numerical solver based on a hybrid Lattice Boltzmann Phase-Field (LB-PF) algorithm is developed to assist the design of the hybrid PCM-MH tank by studying the melting and solidification processes of paraffin-like materials. The present approach is used to model the storage of the heat released by the hydride during the H2 loading process in a phase change material (PCM). The results in terms of Nusselt numbers are used to design an enhanced metal-hydride storage for H2-based energy systems, relevant for a reliable and cost-effective “Hydrogen Economy”. The application of the developed numerical model to the case study demonstrates the feasibility of the posited design. Specifically, the phase change material application significantly increases the heat flux at the metal hydride surface, thus improving the overall system power density.

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