scholarly journals On Numerical Modeling of Thermal Performance Enhancementof a Heat Thermal Energy Storage System Using a Phase Change Material and a Porous Foam

Computation ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 3
Author(s):  
Riheb Mabrouk ◽  
Hassane Naji ◽  
Hacen Dhahri ◽  
Zouhir Younsi

In this investigation, a comprehensive numerical analysis of the flow involved in an open-ended straight channel fully filled with a porous metal foam saturated and a phase change material (paraffin) has been performed using a single relaxation time lattice Boltzmann method (SRT-LBM) at the representative elementary volume (REV) scale. The enthalpy-based approach with three density functions has been employed to cope with the governing equations under the local thermal non-equilibrium (LTNE) condition. The in-house code has been validated through a comparison with a previous case in literature. The pore per inch density (10≤PPI≤60) and porosity (0.7≤ε≤0.9) effects of the metal structure were analyzed during melting/solidifying phenomena at two Reynolds numbers (Re = 200 and 400). The relevant findings are discussed for the LTNE intensity and the entropy generation rate (Ns). Through the simulations, the LTNE hypothesis turned out to be secure and valid. In addition, it is maximum for small PPI value (=10) whatever the parameters deemed. On the other hand, high porosity (=0.9) is advised to reduce the system’s irreversibility. However, at a moderate Re (=200), a small PPI (=10) would be appropriate to mitigate the system irreversibility during the charging case, while a large value (PPI = 60) might be advised for the discharging case. In this context, it can be stated that during the melting period, low porosity (=0.7) with low PPI (=10) improves thermal performance, reduces the system irreversibility and speeds up the melting rate, while for high porosity (=0.9), a moderate PPI (=30) should be used during the melting process to achieve an optimal system.

Fractals ◽  
2015 ◽  
Vol 23 (01) ◽  
pp. 1540003 ◽  
Author(s):  
CHENGBIN ZHANG ◽  
LIANGYU WU ◽  
YONGPING CHEN

The Sierpinski fractal is introduced to construct the porous metal foam. Based on this fractal description, an unsteady heat transfer model accompanied with solidification phase change in fractal porous metal foam embedded with phase change material (PCM) is developed and numerically analyzed. The heat transfer processes associated with solidification of PCM embedded in fractal structure is investigated and compared with that in single-pore structure. The results indicate that, for the solidification of phase change material in fractal porous metal foam, the PCM is dispersedly distributed in metal foam and the existence of porous metal matrix provides a fast heat flow channel both horizontally and vertically, which induces the enhancement of interstitial heat transfer between the solid matrix and PCM. The solidification performance of the PCM, which is represented by liquid fraction and solidification time, in fractal structure is superior to that in single-pore structure.


2022 ◽  
Vol 48 ◽  
pp. 103882
Author(s):  
Adeel Arshad ◽  
Mark Jabbal ◽  
Hamza Faraji ◽  
Pouyan Talebizadehsardari ◽  
Muhammad Anser Bashir ◽  
...  

2020 ◽  
Vol 197 ◽  
pp. 08001
Author(s):  
Bernardo Buonomo ◽  
Lucia Capasso ◽  
Oronzio Manca ◽  
Ferdinando Menale ◽  
Sergio Nardini

In this paper, a two-dimensional numerical investigation on a prototypal solar chimney system integrated with an absorbing capacity wall in a south facade of a building is presented. The capacity wall is composed of a high absorbing plate and an assigned thickness of phase change material in metal foam. The chimney consists of a converging channel with one vertical absorbing wall and the glass plate inclined of 2°. The channel height inside the chimney is equal to 4.0 m, whereas the channel gap is at the inlet equal to 0.34 m and at the outlet it is 0.20 m. The thermal energy storage system is 4.0 m high. The numerical analysis was intended to evaluate the thermal and fluid dynamic behaviors of the solar chimney integrated with a latent thermal energy storage system. The investigation has shown that in all cases PCM has not fully melted during the day and the presence of aluminum foam inside the box attenuates the variation of temperatures during the day. The results show that the three different thickness of the thermal storage system present very similar fluid dynamic and thermal behaviors. For the analyzed configurations, the phase change material does not reach a total melting during the considered day.


2020 ◽  
Vol 116 (7) ◽  
pp. 071901 ◽  
Author(s):  
Tianyu Yang ◽  
Jin Gu Kang ◽  
Patricia B. Weisensee ◽  
Beomjin Kwon ◽  
Paul V. Braun ◽  
...  

Inventions ◽  
2018 ◽  
Vol 3 (4) ◽  
pp. 76 ◽  
Author(s):  
Bernardo Buonomo ◽  
Anna di Pasqua ◽  
Davide Ercole ◽  
Oronzio Manca

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.


Sign in / Sign up

Export Citation Format

Share Document