scholarly journals Melting Within a Spherical Enclosure

1982 ◽  
Vol 104 (1) ◽  
pp. 19-23 ◽  
Author(s):  
F. E. Moore ◽  
Y. Bayazitoglu
Keyword(s):  
Mathematical Model ◽  
Energy Storage ◽  
Flow Field ◽  
Phase Change ◽  
Experimental Evidence ◽  
Phase Change Material ◽  
Saturation Temperature ◽  
Temperature Profiles ◽  
Change Material ◽  
Storage Characteristics

Melting of a phase change material within a spherical enclosure is considered. The phase change material is initially at its saturation temperature. Suddenly the enclosure temperature is increased to a fixed value. The density of the solid is assumed to exceed the density of the liquid, the implication being that the solid continually drops toward the bottom of the shell as melting progresses. This motion of the solid generates a flow field within the liquid. A mathematical model is developed and confirmed by experimental evidence. The interface positions and the temperature profiles for various Stefan and Fourier numbers are determined, and the energy storage characteristics are studied. It is found that the convective effects can be neglected only at small Stefan numbers.

Heat Energy Storage Characteristics of a New Type of PCM Heat Exchange Tube

2012 ◽  
Vol 550-553 ◽  
pp. 3131-3134
Author(s):  
Xiao Qin Zhu ◽  
Zhao Sheng Cao ◽  
Zi Yue Zhu ◽  
Jing Hua Chang ◽  
Hai Ming Gu ◽  
...  
Keyword(s):  
Energy Storage ◽  
Heat Exchange ◽  
Phase Change ◽  
Phase Change Material ◽  
Waste Heat ◽  
Heat Energy ◽  
Heat Exchange Tube ◽  
New Type ◽  
Change Material ◽  
Storage Characteristics

Heat energy storage characteristics of a new type of PCM heat exchange tube was researched, in which it took the traditional double-tube exchanger as the total construction foundation and phase change material(CaCl2•6H2O) was filled in the annular area between the inner tube and the outer tube. As air with different temperatures flowed through the PCM heat exchange tube, temperature measurements were carried out at the inlet and the outlet by the experimental system. The experimental results showed that, a new type of PCM heat exchange tube could store heat energy from the hot air by the phase change material in the annular area, and discharge the stored heat energy into the required fluid if necessary. Thus it has two functions of heat exchange and heat energy storage, and is mainly suitable for recovery and utilizations of heat energy in greenhouses, buildings, air conditioning and manifold industrial afterheat or waste heat.

Numerical Model of Time-Dependent Gas Flows Through Bed of Granular Phase Change Material

2019 ◽  
Vol 17 (06) ◽  
pp. 1950010 ◽  
Author(s):  
Nickolay A. Lutsenko ◽  
Sergey S. Fetsov
Keyword(s):  
Mathematical Model ◽  
Energy Storage ◽  
Phase Change ◽  
Numerical Method ◽  
Phase Change Material ◽  
Time Dependent ◽  
Finite Difference Schemes ◽  
Gas Flows ◽  
Calculation Results ◽  
Change Material

A novel mathematical model and original numerical method for investigating time-dependent gas flows through a bed of granular phase change material (PCM) are proposed and described in detail. Such material is modeled as a porous medium, and continua mechanics method are used for constructing the mathematical model. The numerical method is based on a combination of explicit and implicit finite-difference schemes. Comparison of calculation results with known experimental data demonstrates a very good coincidence. The results of the study can be applied in modeling the thermal energy storage with granular PCM in advanced adiabatic compressed air energy storage and other heat storage devices.

NUMERICAL STUDY OF A SOLAR GREENHOUSE DRYER WITH A PHASE-CHANGE MATERIAL AS AN ENERGY STORAGE MEDIUM

2018 ◽  
Vol 49 (6) ◽  
pp. 509-528 ◽  
Author(s):  
Orawan Aumporn ◽  
Belkacem Zeghmati ◽  
Xavier Chesneau ◽  
Serm Janjai
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Phase Change Material ◽  
Numerical Study ◽  
Storage Medium ◽  
Solar Greenhouse ◽  
Change Material

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.

Sign in / Sign up

Export Citation Format

Share Document