International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395-0056
Volume: 04 Issue: 07 | July -2017
p-ISSN: 2395-0072
www.irjet.net
CFD Analysis and Melting Performance of PCMs in two dimensional sphere Sudha Tripathi1, Archit Tomar2 Mechanical Engineering Department Noida International University, Greater Noida, India -203201 ---------------------------------------------------------------------***---------------------------------------------------------------------
Abstract - Present days the demand of energy is increasing continuously because of high consumption of energy in transport, domestic and industrial sectors. Fossil fuel was only the source of energy that has fulfilled the needs of energy for long time. The high consumption of fossil fuel leads to decrease in availability of reserves and its effect is reflected on the price of fuel which is continuously increases and expected to continue for upcoming years. Solar energy is one of the most important, renewable and clean source of energy that can fulfill all the needs.
In the present numerical study and analysis a two dimensional sphere with hallow section is considered as test section. The grid independent test and time independent test are performed and chosen the appropriate grid size for numerical study. The diameter of hallow section of sphere is 84 mm. The aluminum wall thickness is 1 mm. The isothermal boundary condition is taken for numerical simulation. The three different PCMs (Paraffin wax, Sodium acetate tri-hydrate and Lauric acid) are tested for energy storage and for performance analysis. The energy stored by PCMs is compared. The melt fraction contour and temperature contour are also analyzed at different time of simulation. Key Words: 2 D sphere, phase change materials, thermal energy storage, CFD simulations, melting fraction. Nomenclature Symbol Cpl Cps h Kl Ks L li Si s T Tm β γ μ ρl © 2017, IRJET
Parameter Specific heat (Liquid) Specific heat (Solid) Enthalpy Thermal Conductivity (Liquid) Thermal Conductivity (Solid) Latent heat liquid Source term solid Temperature Melting Point Thermal expansion coefficient Liquid fraction Viscosity Density (Liquid) |
Impact Factor value: 5.181
ρs Abbreviations LHTSS PCMs SAT SHS LHS
Density (Solid) Latent heat thermal storage system Phase changing materials Sodium acetate Trihydrate Sensible heat storage Latent heat storage
1. INTRODUCTION Nowadays the demand of energy is increasing continuously because of high consumption of energy in transport, domestic and industrial sectors. Fossil fuel was only the source of energy that has fulfilled the needs of energy for long time. The high consumption of fossil fuel leads to decrease in availability of reserves and its effect is reflected on the price of fuel which is continuously increases and expected to continue for upcoming years. These fuels are harmful for environment as they are producing CO2 which is main constituent for causing green house effect, global warming etc. Solar energy is one of the most important, renewable and clean source of energy that can fulfill all the needs. Solar energy is intermittent in nature and not continuous, it depends upon weather, seasons, and climate conditions, that is the main drawback of Solar power but the problem of discontinuity can be solve by storing the energy. Thermal energy can be stored by two methods, Sensible heating and Latent heating. In sensible heat storage system thermal energy is stored by raising the temperature of material without change in phase and it is depends on mass, specific heat, temperature difference but in latent heat storage system the energy is stored by absorbing latent heat of material. Y.chen. et al. [1] did numerical analysis using finite element simulation scheme in a rectangular enclosure filled with gallium as a phase change material including natural convection effect and compared with experimental data obtained by Gau and Vishkanta [2]. They chose gallium because its low melting point and its material properties which are available in literature C.Gau et. al. [2] conducted an experiment and reported on the role of natural convection on solid-liquid interface motion and heat transfer during solidification &
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