scholarly journals Thermal properties of sonicated graphene in coconut oil as a phase change material for energy storage in building applications1

2020 ◽  
Vol 15 (4) ◽  
pp. 629-636
Author(s):  
Lulu Safira ◽  
Nandy Putra ◽  
Titin Trisnadewi ◽  
Eny Kusrini ◽  
Teuku Meurah Indra Mahlia
Keyword(s):  
Thermal Conductivity ◽  
Thermal Stability ◽  
Thermal Properties ◽  
Energy Storage ◽  
Melting Point ◽  
Phase Change ◽  
Latent Heat ◽  
Thermal Performance ◽  
Coconut Oil ◽  
Change Material

Abstract This study aims to investigate the thermal properties of a phase change material (PCM) based on coconut oil for building energy storage applications. Coconut oil is classified as an organic PCM composed of fatty acids made from renewable feedstock. However, low thermal conductivity is one of the major drawbacks of organic PCMs that must be improved. Graphene could be an effective material to enhance the thermal performance of organic PCMs. In this study, coconut oil with a latent heat capacity of 114.6 J/g and a melting point of 17.38°C was used. PCMs were prepared by sonicating graphene into coconut oil, as a supporting material. The mass fractions of the prepared PCMs were 0, 0.1, 0.2, 0.3, 0.4 and 0.5. Thermal conductivity tests were performed using a KD2 thermal property analyser under different ambient temperatures of 5, 10, 15, 20 and 25°C simulated with a circulating thermostatic bath. The latent heat, melting point and freezing point were determined through differential scanning calorimetry, the thermal stability was determined using thermogravimetric analysis (TGA) and the morphology and chemical structure were examined using transmission electron microscopy and Fourier-transform infrared spectroscopy, respectively. The results of this study showed that graphene addition to coconut oil improved the thermal performance, with the highest improvement seen in a 0.3 wt% sample at 20°C. The latent heat decreased by 11% owing to molecular movements within the PCM. However, TGA revealed that the composite PCMs showed good thermal stability in ambient building temperature ranges.

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.

The Determination of Thermal Properties of Paraffin-Based Phase Change Material [PCM] Within a Daylighting Panel

2009 ◽  
Author(s):  
John McCloskey ◽  
Amy Fleischer ◽  
Sneha Patel ◽  
Rashida Ng
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Phase Change ◽  
Phase Change Material ◽  
Thermal Performance ◽  
Energy Efficient ◽  
Clear Understanding ◽  
Energy Absorbing ◽  
Change Material

The addition of phase change material (PCM) to a transparent polyester panel is used to create an energy absorbing building material that can be used for daylighting. One of the key development needs of this energy efficient material is the identification of the thermal properties. Without a clear understanding of the thermal properties and thermal performance with embedded solid and liquid PCM, design optimization is not possible. This experiment analyzes the thermal conductivity of various mixtures of thermoplastic polyester and PCMs. It was determined that the addition of PCM slightly increases the thermal conductivity of panels when the PCM is solid. Once the PCM has melted, the panel conductivity is lowered.

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.

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