Thermal energy discharging performance of metal foam/paraffin composite phase change material at pore scale

2021 ◽  
pp. 1-32
Author(s):  
Yuanpeng Yao ◽  
Huiying Wu
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Latent Heat ◽  
Thermal Energy ◽  
Thermal Transport ◽  
Metal Foam ◽  
Volume Shrinkage ◽  
Pore Scale ◽  
Composite Phase Change Material ◽  
Change Material

Abstract In this research, thermal energy discharging performance of metal foam/paraffin composite phase change material (MFPC) is investigated at pore scale through direct simulation. A thermal transport model is first developed for heat discharging of MFPC by incorporating the involved effects of solidification phase transition, foam structure and paraffin volume shrinkage. With this model, the detailed phase interface evolutions, temperature fields and heat flux distributions of MFPC are numerically obtained and analyzed. It is found that once phase change heat discharging of MFPC begins, the solidification front of paraffin quickly forms and extends along the foam skeleton, which results in remarkably extended thermal transport interface to release latent heat as well as improved spatial synergy in phase change. The effect of local thermal non-equilibrium between porous metal foam and paraffin proves to be intrinsic and significant, providing an efficient inner driving force for enhancing latent heat discharging within MFPC. The overall energy discharging performance of MFPC unit is remarkably improved as compared with pure paraffin unit, evidenced by a large enhancement in latent heat release rate (more than 3 times) with only small reduction (2.6 %) in heat capacity. Simultaneously, it is found that the paraffin-air interface for MFPC unit descends much faster due to accelerated volume shrinkage of paraffin in metal foam, resulting in a threefold enhancement in thermally-driven dynamic response rate. This study can help more deeply understanding the energy discharging performance of MFPC and providing fundamental guidance for its application in miniaturized thermal systems.

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.

Experimental investigation of a composite phase change material: Thermal-energy storage and release

2012 ◽  
Vol 48 (1) ◽  
pp. 49-62 ◽  
Author(s):  
Abdelwaheb Trigui ◽  
Mustapha Karkri ◽  
Chokri Boudaya ◽  
Yves Candau ◽  
Laurent Ibos ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Energy Storage ◽  
Phase Change ◽  
Phase Change Material ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Composite Phase Change Material ◽  
Change Material

scholarly journals A Numerical Analysis on a Solar Chimney with an Integrated Thermal Energy Storage with Phase Change Material in Metal Foam

2020 ◽  
Vol 197 ◽  
pp. 08001
Author(s):  
Bernardo Buonomo ◽  
Lucia Capasso ◽  
Oronzio Manca ◽  
Ferdinando Menale ◽  
Sergio Nardini
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Phase Change Material ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Metal Foam ◽  
Fluid Dynamic ◽  
Storage System ◽  
Solar Chimney ◽  
Change Material

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.

Numerical Simulation of Melting in Metal Foam/Paraffin Composite Phase Change Material Using a Physically More Reasonable Macroscale Model

2019 ◽  
Author(s):  
Yuanpeng Yao ◽  
Huiying Wu
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Phase Change Material ◽  
Metal Foam ◽  
Phase Interface ◽  
Change Model ◽  
Composite Phase Change Material ◽  
Convection Dominated ◽  
Change Material ◽  
Change Problem

Abstract In this work, a macroscale model for melting phase change of metal foam/paraffin composite phase change material (MFPC) is developed by employing the enthalpy-porosity method and volume averaging technique. Both cases of varied and unvaried paraffin density during phase change are investigated in the model, and diffusion dominated interstitial heat exchange between paraffin and metal foam is considered along with the convection dominated interstitial heat transfer. The visualization experiments on melting phase change of copper foam/paraffin composite are carried out to validate the developed phase change model. It is found that with consideration of varied density of paraffin, the developed model can effectively solve the real melting problem of MFPC when metal foam is initially filled with solid paraffin. If the Boussinesq approximation is employed (i.e., unvaried paraffin density is considered during phase change), the model is more appropriate for the phase change problem on condition that metal foam can just be filled with liquid paraffin in the end of the melting process. Hence according to different treatments of paraffin density, the application of the phase change model needs to consider the influence of real paraffin filling condition of MFPC. The phase change model considering diffusion dominated interstitial heat transfer between stationary paraffin and metal foam can more accurately capture the solid-liquid phase interface positions as compared with the model only considering the convection dominated interstitial heat transfer. The present study can provide guidance for physically more reasonable simulation of the practical phase change problem of MFPC.

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