scholarly journals The effect of surface area on the properties of shape-stabilized phase change material prepared using palm kernel shell activated carbon

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ahmad Fariz Nicholas ◽  
Mohd Zobir Hussein ◽  
Zulkarnain Zainal ◽  
Tumirah Khadiran

Abstract The effect of the surface area of palm kernel shell activated carbon (PKSAC) on the properties of n-octadecane-encapsulated shape stabilized phase change material (SSPCM) for thermal energy storage (TES) application were studied. Various surface areas of the PKSAC were prepared using different amounts of H3PO4 treatment given to palm kernel shells from 0, 5, 10, 30 and 40% before the activation. The impregnation of n-octadecane into the different surface areas of PKSACs produced SSPCMs with different physico-chemical characteristics. The DSC analysis indicates that the higher the surface area of the PKSAC resulted in the higher freezing temperature due to the higher PCM loading that was encapsulated into the PKSAC pores. The results obtained from XRD, FESEM, Raman spectroscopy, TGA/DTG and leakage study indicate that the PKSAC is a good framework material for the development of n-octadecane-encapsulated SSPCM. It was also found that the surface area and porosity of the frameworks, activated carbon play an important role on the PCM loading percentage and their ability to be used as a thermal energy storage material.

RSC Advances ◽  
2017 ◽  
Vol 7 (36) ◽  
pp. 22170-22177 ◽  
Author(s):  
Jie Han ◽  
Songyang Liu

The addition of activated carbon (10%) effectively enhances the thermal conductivity and heat transfer properties of the MA/H-diatomite-2 composite PCM.


Author(s):  
Tonny Tabassum Mainul Hasan ◽  
Latifa Begum

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.


2021 ◽  
Vol 13 (5) ◽  
pp. 2590
Author(s):  
S. A. M. Mehryan ◽  
Kaamran Raahemifar ◽  
Leila Sasani Gargari ◽  
Ahmad Hajjar ◽  
Mohamad El Kadri ◽  
...  

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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