Investigation of thermal properties and enhanced energy storage/release performance of silica fume/myristic acid composite doped with carbon nanotubes

2019 ◽  
Vol 140 ◽  
pp. 779-788 ◽  
Author(s):  
Ahmet Sarı ◽  
Amir Al-Ahmed ◽  
Alper Bicer ◽  
Fahad A. Al-Sulaiman ◽  
Gökhan Hekimoğlu
Keyword(s):  
Carbon Nanotubes ◽  
Thermal Properties ◽  
Energy Storage ◽  
Silica Fume ◽  
Myristic Acid

scholarly journals Fabrication and Thermal Properties of Capric Acid/Calcinated Iron Tailings/Carbon Nanotubes Composite as Form-Stable Phase Change Materials for Thermal Energy Storage

Minerals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 648
Author(s):  
Peng Liu ◽  
Xiaobin Gu ◽  
Zhikai Zhang ◽  
Jianping Shi ◽  
Jun Rao ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Thermal Properties ◽  
Energy Storage ◽  
Phase Change ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Mass Fraction ◽  
Capric Acid ◽  
Stable Phase ◽  
Impregnation Method

In this study, a novel form-stable phase change material (FSPCM) consisting of calcination iron tailings (CIT), capric acid (CA), and carbon nanotubes (CNT) was prepared using a simple direct melt impregnation method, and a series of tests have been carried out to investigate its properties. The leakage tests showed that CA can be retained in CIT with a mass fraction of about 20 wt.% without liquid leakage during the phase change process. Moreover, the morphology, chemical structure, and thermal properties of the fabricated composite samples were investigated. Scanning electron microscope (SEM) micrographs confirmed that CIT had a certain porous structure to confine CA in composites. According to the Fourier transformation infrared spectroscope (FTIR) results, the CA/CIT/CNT FSPCM had good chemical compatibility. The melting temperature and latent heat of CA/CIT/CNT by differential scanning calorimeter (DSC) were determined as 29.70 °C and 22.69 J/g, respectively, in which the mass fraction of CIT and CNT was about 80 wt.% and 5 wt.%, respectively. The thermal gravity analysis (TGA) revealed that the CA/CIT/CNT FSPCM showed excellent thermal stability above its working temperature. Furthermore, the melting and freezing time of CA/CIT/CNT FSPCM doped with 5 wt.% CNT reduced by 42.86% and 54.55% than those of pure CA, and it showed better heat transfer efficiency. Therefore, based on the above analyses, the prepared CA/CIT/CNT FSPCM is not only a promising candidate material for the application of thermal energy storage in buildings, but it also provides a new approach for recycling utilization of iron tailings.

scholarly journals Preparation and Thermal Properties of Hexadecanol-Myristic Acid Eutectics/ Activated Carbon Composites as Shape-stabilized Phase Change Materials in Thermal Energy Storage

2021 ◽  
Author(s):  
Yanghua CHEN ◽  
Zhaohe WANG ◽  
Minrong GE ◽  
Feng ZHAO
Keyword(s):  
Thermal Stability ◽  
Thermal Properties ◽  
Activated Carbon ◽  
Energy Storage ◽  
Phase Change ◽  
Latent Heat ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Myristic Acid ◽  
Supporting Material

In this study, hexadecanol-myristic acid (HD-MA) binary eutectic mixtures were adsorbed into activated carbon (AC) to prepare the composite phase transition materials(CPCMs). In the hexadecanol-myristic acid/activated carbon (HD-MA/AC) composites, the mixture of HD–MA acted as the phase change energy storage material and the AC was used as the matrix supporting material. Activated carbon is a kind of inorganic supporting material, which has developed pore structure, strong adsorption, high mechanical strength, corrosion resistance and good thermal stability. As the supporting material, activated carbon was helpful to prevent the eutectics from leakage. The chemical structure and crystal phase structure of HD-MA/AC composites were tested by FT-IR and XRD. The microstructure of the composites was observed through field emission scanning electron microscopy (FE-SEM). It was found that the organic binary eutectics were adsorbed on the surface and inside by activated carbon. Thermal properties of the composites were measured by differential scanning calorimetry (DSC). The results of performance test demonstrated that the satisfactory sample CPCM1 melted at 42.38 °C with latent heat of 76.24 J/g and solidified at 38.32 °C with latent heat of 67.08 J/g. The test results of TGA indicated that the prepared composites of hexadecanol-myristic acid/activated carbon possessed great thermal stability and high reliability. It is predicted that the shape-stabilized HD-MA/AC composites have great potential for thermal energy storage.

scholarly journals Demonstration of Phase Change Thermal Energy Storage in Zinc Oxide Microencapsulated Sodium Nitrate

2021 ◽  
Vol 11 (13) ◽  
pp. 6234
Author(s):  
Ciprian Neagoe ◽  
Ioan Albert Tudor ◽  
Cristina Florentina Ciobota ◽  
Cristian Bogdanescu ◽  
Paul Stanciu ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Thermal Properties ◽  
High Temperature ◽  
Energy Storage ◽  
Phase Change ◽  
Thermal Energy ◽  
Sodium Nitrate ◽  
Thermal Energy Storage ◽  
Metal Corrosion ◽  
Scanning Calorimetry

Microencapsulation of sodium nitrate (NaNO3) as phase change material for high temperature thermal energy storage aims to reduce costs related to metal corrosion in storage tanks. The goal of this work was to test in a prototype thermal energy storage tank (16.7 L internal volume) the thermal properties of NaNO3 microencapsulated in zinc oxide shells, and estimate the potential of NaNO3–ZnO microcapsules for thermal storage applications. A fast and scalable microencapsulation procedure was developed, a flow calorimetry method was adapted, and a template document created to perform tank thermal transfer simulation by the finite element method (FEM) was set in Microsoft Excel. Differential scanning calorimetry (DSC) and transient plane source (TPS) methods were used to measure, in small samples, the temperature dependency of melting/solidification heat, specific heat, and thermal conductivity of the NaNO3–ZnO microcapsules. Scanning electron microscopy (SEM) and chemical analysis demonstrated the stability of microcapsules over multiple tank charge–discharge cycles. The energy stored as latent heat is available for a temperature interval from 303 to 285 °C, corresponding to onset–offset for NaNO3 solidification. Charge–self-discharge experiments on the pilot tank showed that the amount of thermal energy stored in this interval largely corresponds to the NaNO3 content of the microcapsules; the high temperature energy density of microcapsules is estimated in the range from 145 to 179 MJ/m3. Comparison between real tank experiments and FEM simulations demonstrated that DSC and TPS laboratory measurements on microcapsule thermal properties may reliably be used to design applications for thermal energy storage.

scholarly journals Multidisciplinary Approaches for Assessing a High Temperature Borehole Thermal Energy Storage Facility at Linköping, Sweden

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4379
Author(s):  
Max Hesselbrandt ◽  
Mikael Erlström ◽  
Daniel Sopher ◽  
Jose Acuna
Keyword(s):  
Thermal Properties ◽  
High Temperature ◽  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Thermal Response ◽  
Site Investigation ◽  
Thermal Response Test ◽  
Response Test ◽  
Crystalline Bedrock

Assessing the optimal placement and design of a large-scale high temperature energy storage system in crystalline bedrock is a challenging task. This study applies and evaluates various methods and strategies for pre-site investigation for a potential high temperature borehole thermal energy storage (HT-BTES) system at Linköping in Sweden. The storage is required to shift approximately 70 GWh of excess heat generated from a waste incineration plant during the summer to the winter season. Ideally, the site for the HT-BTES system should be able to accommodate up to 1400 wells to 300 m depth. The presence of major fracture zones, high groundwater flow, anisotropic thermal properties, and thick Quaternary overburden are all factors that play an important role in the performance of an HT-BTES system. Inadequate input data to the modeling and design increases the risk of unsatisfactory performance, unwanted thermal impact on the surroundings, and suboptimal placement of the HT-BTES system, especially in a complex crystalline bedrock setting. Hence, it is crucial that the subsurface geological conditions and associated thermal properties are suitably characterized as part of pre-investigation work. In this study, we utilize a range of methods for pre-site investigation in the greater Distorp area, in the vicinity of Linköping. Ground geophysical methods, including magnetic and Very Low-Frequency (VLF) measurements, are collected across the study area together with outcrop observations and lab analysis on rock samples. Borehole investigations are conducted, including Thermal Response Test (TRT) and Distributed Thermal Response Test (DTRT) measurements, as well as geophysical wireline logging. Drone-based photogrammetry is also applied to characterize the fracture distribution and orientation in outcrops. In the case of the Distorp site, these methods have proven to give useful information to optimize the placement of the HT-BTES system and to inform design and modeling work. Furthermore, many of the methods applied in the study have proven to require only a fraction of the resources required to drill a single well, and hence, can be considered relatively efficient.

scholarly journals Significantly Improved Dielectric Performance of Poly(1-butene)-Based Composite Films via Filling Polydopamine Modified Ba(Zr0.2Ti0.8)O3-Coated Multiwalled Carbon Nanotubes Nanoparticles

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 285
Author(s):  
Lingfei Li ◽  
Qiu Sun ◽  
Xiangqun Chen ◽  
Zhaohua Jiang ◽  
Yongjun Xu
Keyword(s):  
Carbon Nanotubes ◽  
Dielectric Constant ◽  
Energy Storage ◽  
Composite Film ◽  
Multiwalled Carbon Nanotubes ◽  
Sol Gel ◽  
Composite Films ◽  
Weak Electric Field ◽  
Multiwalled Carbon ◽  
Dielectric Performance

The low dielectric constant of the nonpolar polymer poly(1-butene) (PB-1) limits its application as a diaphragm element in energy storage capacitors. In this work, Ba(Zr0.2Ti0.8)O3-coated multiwalled carbon nanotubes (BZT@MWCNTs) were first prepared by using the sol–gel hydrothermal method and then modified with polydopamine (PDA) via noncovalent polymerization. Finally, PB-1 matrix composite films filled with PDA-modified BZT@MWCNTs nanoparticles were fabricated through a solution-casting method. Results indicated that the PDA-modified BZT@MWCNTs had good dispersion and binding force in the PB-1 matrix. These characteristics improved the dielectric and energy storage performances of the films. Specifically, the PDA-modified 10 vol% BZT@ 0.5 vol% MWCNTs/PB-1 composite film exhibited the best dielectric performance. At 1 kHz, the dielectric constant of this film was 25.43, which was 12.7 times that of pure PB-1 films. Moreover, its dielectric loss was 0.0077. Furthermore, under the weak electric field of 210 MV·m−1, the highest energy density of the PDA-modified 10 vol% BZT@ 0.5 vol% MWCNTs/PB-1 composite film was 4.57 J·cm−3, which was over 3.5 times that of PB-1 film (≈1.3 J·cm−3 at 388 MV·m−1).

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