scholarly journals Numerical investigation on latent thermal energy storage in shell and corrugated internal tube with PCM and metal foam

2021 ◽  
Vol 312 ◽  
pp. 03003
Author(s):  
Bernardo Buonomo ◽  
Francescantonio Di Somma ◽  
Oronzio Manca ◽  
Sergio Nardini ◽  
Renato Elpidio Plomitallo
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Numerical Investigation ◽  
Latent Heat ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Metal Foam ◽  
Internal Surface ◽  
Paraffin Wax ◽  
Melting Time

A numerical investigation on Latent Heat Thermal Energy Storage System (LHTESS) based on an aluminum foam totally filled with phase change material (PCM) is accomplished. The PCM used is a pure paraffin wax with melting over a range of temperature and a high latent heat of fusion. The LHTESS geometry under investigation is a vertical shell and tube. The corrugated internal surface of the hollow cylinder is assumed at a constant temperature above the PCM melting temperature. The other external surfaces are assumed adiabatic. The paraffin wax phase change process is modelled with the enthalpy-porosity theory, while the metal foam is considered as a porous media obeying to the Darcy-Forchheimer law. Local thermal non-equilibrium (LTNE) model is assumed to analyze the heat transfer in the metal foam. The governing equations are solved employing the Ansys-Fluent code. The numerical simulations results, reported as a function of time, and concerning the LHTESS charging phase, are compared in terms of melting time, average temperature and energy storage rate. The corrugated internal surface effect is analyzed with respect to the wavelength and wave amplitude of the corrugation.

scholarly journals Numerical Study of Latent Heat Thermal Energy Storage Enhancement by Nano-PCM in Aluminum Foam

Inventions ◽  
2018 ◽  
Vol 3 (4) ◽  
pp. 76 ◽  
Author(s):  
Bernardo Buonomo ◽  
Anna di Pasqua ◽  
Davide Ercole ◽  
Oronzio Manca
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Phase Change Material ◽  
Latent Heat ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Metal Foam ◽  
Storage System ◽  
Melting Time ◽  
Change Material

Thermal storage system (TES) with phase change material (PCM) is an important device to store thermal energy. It works as a thermal buffer to reconcile the supply energy with the energy demand. It has a wide application field, especially for solar thermal energy storage. The main drawback is the low value of thermal conductivity of the PCM making the system useless for thermal engineering applications. A way to resolve this problem is to combine the PCM with a highly conductive material like metal foam and/or nanoparticles. In this paper a numerical investigation on the metal foam effects in a latent heat thermal energy storage system, based on a phase change material with nanoparticles (nano-PCM), is accomplished. The modelled TES is a typical 70 L water tank filled with nano-PCM with pipes to transfer thermal energy from a fluid to the nano-PCM. The PCM is a pure paraffin wax and the nanoparticles are in aluminum oxide. The metal foam is made of aluminum with assigned values of porosity. The enthalpy-porosity theory is employed to simulate the phase change of the nano-PCM and the metal foam is modelled as a porous media. Numerical simulations are carried out using the Ansys Fluent code. The results are shown in terms of melting time, temperature at varying of time, and total amount of stored energy.

Numerical Investigation on the Effect of Aluminum Foam in a Latent Thermal Energy Storage

2015 ◽  
Author(s):  
Bernardo Buonomo ◽  
Davide Ercole ◽  
Oronzio Manca ◽  
Hasan Celik ◽  
Moghtada Mobedi
Keyword(s):  
Heat Transfer ◽  
Energy Storage ◽  
Phase Change ◽  
Numerical Investigation ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Metal Foam ◽  
Local Thermal Equilibrium ◽  
Melting Time ◽  
High Porosity

In this paper, a numerical investigation on Latent Heat Thermal Energy Storage System (LHTESS) based on a phase change material (PCM) is accomplished. The geometry of the system under investigation is a vertical shell and tube LHTES made with two concentric aluminum tubes. The internal surface of the hollow cylinder is assumed at a constant temperature above the melting temperature of the PCM to simulate the heat transfer from a hot fluid. The other external surfaces are assumed adiabatic. The phase change of the PCM is modeled with the enthalpy porosity theory while the metal foam is considered as a porous media that obeys to the Darcy-Forchheimer law. The momentum equations are modified by adding of suitable source term which it allows to model the solid phase of PCM and natural convection in the liquid phase of PCM. Both local thermal equilibrium (LTE) and local thermal non-equilibrium (LTNE) models are examined. Results as a function of time for the charging phase are carried out for different porosities and assigned pore per inch (PPI). The results show that at high porosity the LTE and LTNE models have the same melting time while at low porosity the LTNE has a larger melting time. Moreover, the presence of metal foam improves significantly the heat transfer in the LHTES giving a very faster phase change process with respect to pure PCM, reducing the melting time more than one order of magnitude.

Numerical Investigation on a Latent Thermal Energy Storage With Aluminum Foam

2016 ◽  
Author(s):  
Bernardo Buonomo ◽  
Davide Ercole ◽  
Oronzio Manca ◽  
Sergio Nardini
Keyword(s):  
Heat Transfer ◽  
Energy Storage ◽  
Phase Change ◽  
Numerical Investigation ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Metal Foam ◽  
Local Thermal Equilibrium ◽  
Melting Time ◽  
High Porosity

In this paper, a numerical investigation on Latent Heat Thermal Energy Storage System (LHTESS) based on a phase change material (PCM) in a metal foam is accomplished. A vertical shell and tube LHTESS made with two concentric aluminum tubes is investigated. The internal surface of the hollow cylinder is at a constant temperature above the PCM melting temperature to simulate the heat transfer from a hot fluid. The other external surfaces are assumed adiabatic. The phase change of the PCM is modeled with the enthalpy porosity theory while the metal foam is considered as a porous media that obeys to the Darcy-Forchheimer law. Local thermal non-equilibrium (LTNE) model is assumed to analyze the metal foam and some comparison are accomplished with the local thermal equilibrium model assumption. The governing equations are solved employing the Ansys-Fluent 15 code. Numerical simulations for PCM, PCM in the porous medium in LTE and in LTNE assumptions are obtained. Results as a function of time for the charging phase are carried out for different porosities and assigned pore per inch (PPI). The results show that at high porosity the LTE and LTNE models have the same melting time while at low porosity the LTNE has a larger melting time. Moreover, the presence of metal foam improves significantly the heat transfer in the LHTESS giving a very faster phase change process with respect to pure PCM, reducing the melting time more than one order of magnitude.

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.

scholarly journals Nano-Enhanced Phase Change Materials in Latent Heat Thermal Energy Storage Systems: A Review

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3821
Author(s):  
Kassianne Tofani ◽  
Saeed Tiari
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Latent Heat ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Phase Change Materials ◽  
Storage Systems ◽  
Heat Pipes ◽  
Energy Storage Systems ◽  
Thermal Energy Storage Systems

Latent heat thermal energy storage systems (LHTES) are useful for solar energy storage and many other applications, but there is an issue with phase change materials (PCMs) having low thermal conductivity. This can be enhanced with fins, metal foam, heat pipes, multiple PCMs, and nanoparticles (NPs). This paper reviews nano-enhanced PCM (NePCM) alone and with additional enhancements. Low, middle, and high temperature PCM are classified, and the achievements and limitations of works are assessed. The review is categorized based upon enhancements: solely NPs, NPs and fins, NPs and heat pipes, NPs with highly conductive porous materials, NPs and multiple PCMs, and nano-encapsulated PCMs. Both experimental and numerical methods are considered, focusing on how well NPs enhanced the system. Generally, NPs have been proven to enhance PCM, with some types more effective than others. Middle and high temperatures are lacking compared to low temperature, as well as combined enhancement studies. Al2O3, copper, and carbon are some of the most studied NP materials, and paraffin PCM is the most common by far. Some studies found NPs to be insignificant in comparison to other enhancements, but many others found them to be beneficial. This article also suggests future work for NePCM and LHTES systems.

Improved Melting and Solidification in Thermal Energy Storage Through Topology Optimization of Highly Conductive Fins

2017 ◽  
Author(s):  
Alberto Pizzolato ◽  
Adriano Sciacovelli ◽  
Vittorio Verda
Keyword(s):  
Topology Optimization ◽  
Energy Storage ◽  
Phase Change ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Phase Change Materials ◽  
Optimization Method ◽  
Periodic Pattern ◽  
Melting Time ◽  
Bottom Part

Thermal energy storage units based on phase change materials (PCMs) need a fine design of highly conductive fins to improve the average heat transfer rate. In this paper, we seek the optimal distribution of a highly conductive material embedded in a PCM through a density-based topology optimization method. The phase change problem is solved through an enthalpy-porosity model, which accounts for natural convection in the fluid. Results show fundamental differences in the optimized layout between the solidification and the melting case. Fins optimized for solidification show a quasi-periodic pattern along the angular direction. On the other hand, fins optimized for melting elongate mostly in the bottom part of the unit leaving only two short baffles at the top. In both cases, the optimized structures show non-intuitive details which could not be obtained neglecting fluid flow. These additional features reduce the solidification and melting time by 11 % and 27 % respectively compared to a structure optimized for diffusion.

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