scholarly journals Numerical Study on the Thermal Performance of a Single U-Tube Borehole Heat Exchanger Using Nano-Enhanced Phase Change Materials

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5156 ◽  
Author(s):  
Hossein Javadi ◽  
Javier F. Urchueguia ◽  
Seyed Soheil Mousavi Ajarostaghi ◽  
Borja Badenes
Keyword(s):  
Heat Exchanger ◽  
Phase Change ◽  
Phase Change Material ◽  
Thermal Performance ◽  
Phase Change Materials ◽  
Volume Fraction ◽  
Melting Rate ◽  
Cu Nanoparticles ◽  
Borehole Heat Exchanger ◽  
Change Material

To investigate the impacts of using nano-enhanced phase change materials on the thermal performance of a borehole heat exchanger in the summer season, a three-dimensional numerical model of a borehole heat exchanger is created in the present work. Seven nanoparticles including Cu, CuO, Al2O3, TiO2, SiO2, multi-wall carbon nanotube, and graphene are added to the Paraffin. Considering the highest melting rate and lowest outlet temperature, the selected nano-enhanced phase change material is evaluated in terms of volume fraction (0.05, 0.10, 0.15, 0.20) and then the shape (sphere, brick, cylinder, platelet, blade) of its nanoparticles. Based on the results, the Paraffin containing Cu and SiO2 nanoparticles are found to be the best and worst ones in thermal performance improvement, respectively. Moreover, it is indicated that the increase in the volume fraction of Cu nanoparticles could enhance markedly the melting rate, being 0.20 the most favorable value which increased up to 55% the thermal conductivity of the nano-enhanced phase change material compared to the pure phase change material. Furthermore, the blade shape is by far the most appropriate shape of the Cu nanoparticles by considering about 85% melting of the nano-enhanced phase change material.

scholarly journals Designs of PCM based heat exchangers constructions for thermal energy storage tanks – examples and case study for selected design

2018 ◽  
Vol 70 ◽  
pp. 01010
Author(s):  
Marta Kuta ◽  
Dominika Matuszewska ◽  
Tadeusz Michał Wójcik
Keyword(s):  
Energy Storage ◽  
Heat Exchanger ◽  
Phase Change ◽  
Phase Change Material ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Phase Change Materials ◽  
New Technologies ◽  
Tube Heat Exchanger ◽  
Change Material

Increasing energy consumption in residential and public buildings requires development of new technologies for thermal energy production and storage. One of possibilities for the second listed need is the use of phase change materials (PCMs). This work is focused on solutions in this area and consists of two parts. First one is focused on different designs of thermal energy storage (TES) tanks based on the phase change materials. The second part is the analysis of tests results for TES tank containing shelf and tube heat exchanger and filled with phase change material. Thermal energy storage tank is analyzed in order to use it in domestic heating and hot utility water installations. The aim of this research was to check the applicability of phase change material for mentioned purpose. Results show that using phase change materials for thermal energy storage can increase amount of stored heat. The use of properly selected PCM and heat exchanger enables the process of thermal energy storing and releasing to become more efficient.

scholarly journals Application of Phase Change Material-Based Thermal Capacitor in Double Tube Heat Exchanger—A Numerical Investigation

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4327
Author(s):  
Matthew Fong ◽  
Jundika Kurnia ◽  
Agus P. Sasmito
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Phase Change ◽  
Phase Change Material ◽  
Phase Change Materials ◽  
Oscillation Period ◽  
Temperature Oscillation ◽  
Tube Heat Exchanger ◽  
Inlet Conditions ◽  
Change Material

In many heat transfer related applications, there is a need for a stable, constant supply temperature. As a result, the integration of intermittent renewable sources of heat into these processes can prove to be challenging, requiring special temperature smoothing devices or strategies. This study focuses on the application of phase change materials integrated into a double tube heat exchanger as a possible thermal smoothing device. The objective of this study is to evaluate the ability of the exchanger to smoothen out temperature variations within the cold stream outlet while the hot stream is subject to oscillating inlet conditions. A computational fluid dynamics approach is used where a numerical model is developed, validated and then used to model the conjugate heat transfer within the heat exchanger. Four organic phase change materials (PCM) with different phase change temperatures were selected for investigation (myristic, octadecane, eicosane, and wax) to study the relationship between melting temperature and stabilization performance. A parametric study was then conducted by varying the Reynolds number of the flow as well as temperature oscillation period and amplitude to study the sensitivity of the system. The results confirm the potential of a phase change material-based thermal capacitor at dampening oscillations across the heat exchanger.

Mathematical Model to Describe Thermal Behavior of Phase Change Materials Contained in a Cylindrical Enclosure

2003 ◽  
Author(s):  
Ahmed ElGafy ◽  
Osama Mesalhy ◽  
Khalid Lafdi ◽  
K. Bowman
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Latent Heat ◽  
Thermal Performance ◽  
Phase Change Materials ◽  
Solid Phase ◽  
Operating Conditions ◽  
High Melting ◽  
Space Applications ◽  
Change Material

Heat transfer processes undergoing liquid-solid phase transformation have been of continuing interest for many researchers. Phase Change Materials, (PCMs); have received great consideration in electronic industry for cooling of electronics and in telecommunication equipment to control internal temperature under emergency operating conditions. High melting temperature materials have been proposed as thermal energy storage mediums in space applications because of their high melting temperatures and latent heat. In the present work, a numerical simulation is developed to predict the thermal performance of a phase change material of high melting point in a cylindrical enclosure. In this simulation the phases are assumed to be homogeneous and a source term, S, arises from melting and solidification processes is considered as a function of the latent heat of fusion and the liquid phase fraction. By introducing the thermo-physical properties of one of those materials, the thermal performance of it as a phase change material is predicted.

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