Effect of orientation and heat input on behavior of solid-liquid interface boundary of phase change material in latent heat thermal energy storage container

2021 ◽  
pp. 103539
Author(s):  
J.P. Hadiya ◽  
Chirag Patel ◽  
Maithil Dangarwala ◽  
Sachin Dangar ◽  
Narayan Changlani
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Heat Input ◽  
Interface Boundary ◽  
Storage Container ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Change Material

High Temperature Thermal Energy Storage Using EPCM: The Effect of Void

2014 ◽  
Author(s):  
Laura Solomon ◽  
Ali F. Elmozughi ◽  
Sudhakar Neti ◽  
Alparslan Oztekin
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Liquid Interface ◽  
Heat Of Fusion ◽  
Steel Shell ◽  
Initial Location ◽  
Solid Liquid Interface ◽  
Solid Liquid

Heat transfer simulations and predictions of the thermal energy storage capability using encapsulated phase change materials (EPCM) at high temperatures are conducted. NaNO3 is considered as a phase change material (PCM). The PCM is encapsulated by a stainless steel shell. Two dimensional simulations of a cylindrical capsule are considered. The effects of the buoyancy driven convection in the molten PCM as well as the thermal and volume expansions due to phase change are included in the thermal analysis. An initial void level of 20% is considered in the simulations of the EPCM capsules. EPCM capsules store energy not only by sensible heat but also by the latent heat of fusion as heat is stored or extracted from the capsule. The solid/liquid interface inside the PCM propagates radially inward during the melting process. The effect of a void on the thermal energy storage and on the evolution of the solid/liquid interface is characterized. Two cases are presented, that of a local void initially at the top of the EPCM capsule and an initially random void distribution. The initial location of the void within the capsule has a profound effect on the shape of the solid/liquid interface and the isotherms within the capsule. The results of these simulations can be the basis for the design of an EPCM based thermocline for thermal energy storage (TES) at a concentrated solar power plant and other applications.

Thermal Energy Storage Through Melting of a Commercial Phase Change Material in an Annulus with Radially Divergent Longitudinal Fins

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Tonny Tabassum Mainul Hasan ◽  
Latifa Begum
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Phase Change Material ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Storage System ◽  
Operating Conditions ◽  
Melting Time ◽  
Bottom Part ◽  
Change Material

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.

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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