Apparent heat capacity method to investigate heat transfer in a composite phase change material

2020 ◽  
Vol 28 ◽  
pp. 101239 ◽  
Author(s):  
Y. Khattari ◽  
T. El Rhafiki ◽  
N. Choab ◽  
T. Kousksou ◽  
M. Alaphilippe ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Capacity ◽  
Phase Change ◽  
Phase Change Material ◽  
Apparent Heat Capacity ◽  
Composite Phase Change Material ◽  
Change Material ◽  
Investigate Heat Transfer ◽  
Capacity Method

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.

Fluid Flow and Heat Transfer Characteristics of Microencapsulated Phase Change Material Slurry in Turbulent Flow

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Hessam Taherian ◽  
Jorge L. Alvarado ◽  
Kalpana Tumuluri ◽  
Curt Thies ◽  
Chan-Hyun Park
Keyword(s):  
Heat Transfer ◽  
Heat Capacity ◽  
Fluid Flow ◽  
Turbulent Flow ◽  
Phase Change ◽  
Phase Change Material ◽  
Flow Conditions ◽  
Microencapsulated Phase Change Material ◽  
Change Material ◽  
Turbulent Flow Conditions

Microencapsulated phase change material (MPCM) slurry is consisted of a base fluid in which MPCM is dispersed. Due to apparent high heat capacity associated with phase change process, MPCM slurry can be used as a viable heat transfer fluid (HTF) for turbulent flow conditions. Heat transfer and fluid flow properties of the slurry in turbulent flow (3000 < Re < 6000) were determined experimentally. Dynamic viscosity of the MPCM slurry was measured at different temperatures close to the melting point of the material (20–30 °C). Pressure drop measurements under turbulent flow conditions were recorded for 6 MPCM samples at various concentrations. The pressure drop of the MPCM slurry was comparable to that of water despite the higher viscosity of the slurry. The effect of heat flux, MPCM mass concentration, flow rate and the type of phase change material was investigated. The effective heat capacity of slurry at the location where phase change occurs was found to be considerably higher than that of water. A nondimensional Nusselt number correlation was proposed in order to facilitate design of heat transfer loops with MPCM slurries as working fluid.

Hydrogen Fast Fill Modeling and Optimization of Cylinders Lined With Phase Change Material

2020 ◽  
Author(s):  
Miroslaw Liszka ◽  
Aleksandr Fridlyand ◽  
Ambalavanan Jayaraman ◽  
Michael Bonnema ◽  
Chakravarthy Sishtla
Keyword(s):  
Heat Capacity ◽  
Phase Change ◽  
Phase Change Material ◽  
Initial Conditions ◽  
Filling Process ◽  
Ansys Fluent ◽  
Single Temperature ◽  
Change Material ◽  
Capacity Method ◽  
Gas Properties

Abstract This work is a continuation of a previous study (IMECE2019-11449) which sought to explore the feasibility and means of successfully modeling the hydrogen fast filling process of cylinders lined with phase change material (PCM) entirely in CFD software. The first focus of this work was to address the simplistic approach of how the liner temperature was modelled in the previous study. Previously, the entire liner was assigned a single temperature which was obtained and updated through the lumped heat capacity method. This meant that the hotter gas at the end of the cylinder opposite the inlet was in contact with a liner at a temperature lower than could realistically be expected. This was remedied by splitting the liner into four sections. Two sections were used for the curved portions at each end of the cylinder, and the straight wall section was split into two. Each section had its temperature independently calculated through the lumped heat capacity method. A temperature difference on the order of a ten degrees Celsius was observed between the different sections of the liner prior to latent heating beginning. The mass averaged temperature of the hydrogen inside the cylinder obtained with the sectioned wall case matched that obtained with the single wall temperature almost exactly, less than a degree difference. Despite the unexpected findings of the average hydrogen temperature not changing much when the wall is split into sections, this approach was still taken with all the cases completed in this study. The liner could be split into a greater amount of sections than four, but this was considered unnecessary due to the findings regarding the overall hydrogen temperature. Four sections were considered adequate and used to model the temperature gradient along the wall or liner. The effect of gravity on the filling process was also explored based on the orientation of the cylinder. This required completing three-dimensional simulations to accurately simulate buoyancy driven flow in horizontally mounted cylinders. All the simulations were completed with ANSYS Fluent 2019 R1 without the use of additional software to handle the heat transfer involving the PCM. All simulations were completed with the coupled pressure-based solver and K-Omega SST turbulence model. The gas properties were obtained from tables generated from NIST properties (REFPROP) available within ANSYS Fluent to limit the amount of error in the accumulated mass within the cylinder due to inaccurate gas properties. The initial conditions for the gas and liner temperatures were 25°C and 100 bar for the gas pressure. A constant mass flow rate of 0.02174 kg/s at a temperature 0°C were used as the initial conditions for the inlet hydrogen gas.

Nanoparticle enhanced paraffin and tailing ceramic composite phase change material for thermal energy storage

2020 ◽  
Vol 4 (9) ◽  
pp. 4547-4557
Author(s):  
Runfeng Li ◽  
Yang Zhou ◽  
Xili Duan
Keyword(s):  
Heat Transfer ◽  
Energy Storage ◽  
Phase Change ◽  
Phase Change Material ◽  
Ceramic Composite ◽  
Physical Stability ◽  
Enhanced Heat Transfer ◽  
Composite Phase Change Material ◽  
Change Material ◽  
Transfer Properties

A nanoparticle-paraffin-tailing ceramic composite phase change material is developed with good chemical and physical stability and enhanced heat transfer properties.

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